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Sample records for composite cawo4 detectors

  1. Synthesis and photoluminescence properties of Sm3+-doped CaWO4 nanoparticles

    International Nuclear Information System (INIS)

    Xiao Qi; Zhou Qitao; Li Ming

    2010-01-01

    The Sm 3+ -doped CaWO 4 nanoparticles were synthesized by hydrothermal method. The room temperature photoluminescence (PL) spectra of Sm 3+ -doped CaWO 4 nanoparticles doped with different Sm 3+ concentrations under 405 nm excitation have been investigated. The PL spectra showed four strong emission peaks at 460, 571, 609, and 653 nm. The first emission peak at 460 nm could be due to a structural defect of the lattice, an oxygen-deficient WO 3 complex. The other three emissions at 571, 609, and 653 nm were due to the f-f forbidden transitions of the 4f electrons of Sm 3+ , corresponding to 4 G 5/2 → 6 H 5/2 (571 nm), 6 H 7/2 (609 nm), and 6 H 9/2 (653 nm), respectively. In addition, the optimum Sm 3+ concentration in CaWO 4 nanoparticles for optical emission was determined to be 1.0%. The Sm 3+4 G 5/2 → 6 H 7/2 (609 nm) emission intensity of Sm 3+ -doped CaWO 4 nanoparticles significantly increased with the increase of Sm 3+ concentration, and showed a maximum when Sm 3+ doping content was 1.0%. If Sm 3+ concentration continued to increase, namely more than 1.0%, the Sm 3+4 G 5/2 → 6 H 7/2 emission intensity would decrease. The present materials might be a promising phosphor for white-light LED applications.

  2. The luminescence of CaWO4: Bi single crystals

    International Nuclear Information System (INIS)

    Zorenko, Yu.; Pashkovsky, M.; Voloshinovskii, A.; Kuklinski, B.; Grinberg, M.

    2006-01-01

    Influence of doping with Bi 3+ ions and Bi 3+ -Na + or Bi 3+ -Li + ions pairs on luminescence, emission kinetics and light yield of CaWO 4 crystals has been investigated. It has been shown that under excitation in the A-band at 272 and 287nm, related to the Bi 3+ ions absorption, the luminescence peaked at 468nm decaying with time τ=0.41μs is observed. For bismuth concentration 50-500ppm and the equimolar concentrations of the Bi 3+ ions accompanied by Na + or Li + ions compensators the significant suppression of the phosphorescence peaked at 520nm, related to the defect WO 3 -V O complex, and an improvement of scintillation characteristics of the CaWO 4 are noticed. Energy transfer from the defect WO 3 -V O and regular WO 4 2- oxy-anions to Bi 3+ ions have been observed at room temperatures and discussed

  3. A study of electron excitations in CaWO sub 4 and PbWO sub 4 single crystals

    CERN Document Server

    Muerk, V; Mihoková, E; Nitsch, K

    1997-01-01

    The excitation spectra of photo- and thermo-luminescence were compared in the VUV-UV spectral region in CaWO sub 4 and PbWO sub 4 scheelite tungstates. Temperature dependences of emission intensities and decay times were measured for PbWO sub 4 in the 80-300 K range and approximated by a simple phenomenological model. The energy level structure of the emission centre excited state and related kinetic processes are discussed for both tungstates. (author)

  4. Synthesis of Nanocrystalline CaWO4 as Low-Temperature Co-fired Ceramic Material: Processing, Structural and Physical Properties

    Science.gov (United States)

    Vidya, S.; Solomon, Sam; Thomas, J. K.

    2013-01-01

    Nanocrystalline scheelite CaWO4, a promising material for low-temperature co-fired ceramic (LTCC) applications, has been successfully synthesized through a single-step autoignition combustion route. Structural analysis of the sample was performed by powder x-ray diffraction (XRD), Fourier-transform infrared spectroscopy, and Raman spectroscopy. The XRD analysis revealed that the as-prepared sample was single phase with scheelite tetragonal structure. The basic optical properties and optical constants of the CaWO4 nanopowder were studied using ultraviolet (UV)-visible absorption spectroscopy, which showed that the material was a wide-bandgap semiconductor with bandgap of 4.7 eV at room temperature. The sample showed poor transmittance in the ultraviolet region but maximum transmission in the visible/near-infrared regions. The photoluminescence spectra recorded at different temperatures showed intense emission in the green region. The particle size estimated from transmission electron microscopy was 23 nm. The feasibility of CaWO4 for LTCC applications was studied from its sintering behavior. The sample was sintered at a relatively low temperature of 810°C to high density, without using any sintering aid. The surface morphology of the sintered sample was analyzed by scanning electron microscopy. The dielectric constant and loss factor of the sample measured at 5 MHz were found to be 10.50 and 1.56 × 10-3 at room temperature. The temperature coefficient of the dielectric constant was -88.71 ppm/°C. The experimental results obtained in this work demonstrate the potential of nano-CaWO4 as a low-temperature co-fired ceramic as well as an excellent luminescent material.

  5. Optical properties of CaWO4 and CaMoO4 crystals in the 4-25 eV region

    International Nuclear Information System (INIS)

    Grasser, R.; Pitt, E.; Scharmann, A.; Zimmerer, G.

    1975-04-01

    The reflection spectra of CaWO 4 and CaMoO 4 single crystals were measured in the region between 4 and 25 eV. The measurements were performed using the electron synchrotron DESY as a light source. Both crystals show very similar spectral features. A relatively sharp, well separated low energy peak is accompanied on the high energy side by two groups of maxima, each group containing three broad main reflection bands which strongly overlap. Besides this, a less pronounced structure is observed over the whole spectral region. The experimental results are discussed in terms of semiempirical MO calculations of the anionic transition metal oxo complexes. (orig.) [de

  6. Scintillation light detectors with Neganov Luke amplification

    Science.gov (United States)

    Isaila, C.; Boslau, O.; Coppi, C.; Feilitzsch, F. v.; Goldstraß, P.; Jagemann, T.; Jochum, J.; Kemmer, J.; Lachenmaier, T.; Lanfranchi, J.-C.; Pahlke, A.; Potzel, W.; Rau, W.; Stark, M.; Wernicke, D.; Westphal, W.

    2006-04-01

    For an active suppression of the gamma and electron background in the Cryogenic Rare Event Search with Superconducting Thermometers (CRESST) dark matter experiment both phonons and scintillation light generated in a CaWO 4 crystal are detected simultaneously. The phonon signal is read out by a transition edge sensor (TES) on the CaWO 4 crystal. For light detection a silicon absorber equipped with a TES is employed. An efficient background discrimination requires very sensitive light detectors. The threshold can be improved by applying an electric field to the silicon crystal leading to an amplification of the thermal signal due to the Neganov-Luke effect. Measurements showing the improved sensitivity of the light detectors as well as future steps for reducing the observed extra noise will be presented.

  7. Scintillation light detectors with Neganov-Luke amplification

    International Nuclear Information System (INIS)

    Isaila, C.; Boslau, O.; Coppi, C.; Feilitzsch, F. von; Goldstrass, P.; Jagemann, T.; Jochum, J.; Kemmer, J.; Lachenmaier, T.; Lanfranchi, J.-C.; Pahlke, A.; Potzel, W.; Rau, W.; Stark, M.; Wernicke, D.; Westphal, W.

    2006-01-01

    For an active suppression of the gamma and electron background in the Cryogenic Rare Event Search with Superconducting Thermometers (CRESST) dark matter experiment both phonons and scintillation light generated in a CaWO 4 crystal are detected simultaneously. The phonon signal is read out by a transition edge sensor (TES) on the CaWO 4 crystal. For light detection a silicon absorber equipped with a TES is employed. An efficient background discrimination requires very sensitive light detectors. The threshold can be improved by applying an electric field to the silicon crystal leading to an amplification of the thermal signal due to the Neganov-Luke effect. Measurements showing the improved sensitivity of the light detectors as well as future steps for reducing the observed extra noise will be presented

  8. A single-phase white light emitting Pr3+ doped Ba2CaWO6 phosphor: synthesis, photoluminescence and optical properties

    Science.gov (United States)

    Sreeja, E.; Vidyadharan, Viji; Jose, Saritha K.; George, Anns; Joseph, Cyriac; Unnikrishnan, N. V.; Biju, P. R.

    2018-04-01

    Pr3+ doped Ba2CaWO6 phosphor were prepared by traditional high-temperature solid-state reaction technique. The structure evolution was systematically investigated by X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analysis. The X-ray powder diffraction patterns indicate that the prepared phosphors crystallized in the cubic double-perovskite structure. The functional groups were identified using FTIR spectra and the elements present in the composition were confirmed by the EDS profile. The morphology of the phosphor was identified using SEM and TEM analysis. The PL spectra illustrated that these phosphors could be efficiently excited by charge transfer band of host and the maximum luminescence intensity was observed at 0.06 wt% of Pr3+ ion. Upon the charge transfer band excitation, emission spectra showed peaks at 489, 532, 647, 685 and 737 nm corresponding to 3P0→3H4, 3P1→3H5, 3P0→3F2, 3P0→3F3 and 3P0→3F4 transitions respectively. The concentration quenching of Ba2CaWO6:Pr3+ phosphor can be mainly attributed to dipole-dipole interaction. The CIE coordinates were estimated to be close to the white region. The decay curves are well fitted with double exponential decay models. The standard and modified Judd-Ofelt (JO) theories were used to determine the Judd-Ofelt intensity parameters, radiative transition probabilities and branching ratios. The optical properties indicate that Ba2CaWO6:Pr3+ phosphors can produce white light emission from a single phase host and its potential application for solid-state lighting and display devices.

  9. Enhanced structural and optical properties of the polyaniline-calcium tungstate (PANI-CaWO4 nanocomposite for electronics applications

    Science.gov (United States)

    Sabu, N. Aloysius; Francis, Xavier; Anjaly, Jose; Sankararaman, S.; Varghese, Thomas

    2017-06-01

    In this article, we report the synthesis and characterization of polyaniline-calcium tungstate nanocomposite, a novel material for potential applications. The PANI-CaWO4 nanocomposite was prepared by in situ oxidative polymerization of aniline in the presence of CaWO4 nanoparticles dispersed in ethanol. Investigations using X-ray diffraction, Fourier-transformed infrared spectroscopy, UV-visible, photoluminescence and Raman spectroscopy confirmed the formation of the nanocomposite of PANI with CaWO4 nanoparticles. Scanning electron microscopy revealed almost uniform distribution of CaWO4 nanoparticles in the polyaniline matrix. These studies also confirmed electronic structure modification as a result of incorporating CaWO4 nanoparticles in PANI. Composite formation resulted in large decrease in the optical band gap and enhanced photoluminescence. The augmented structural, optical and photoluminescence properties of the PANI-CaWO4 nanocomposite can be used to explore potential applications in micro- and optoelectronics. This is the first report presenting synthesis and characterization of the PANI-CaWO4 nanocomposite.

  10. Application of the Neganov-Luke effect to low-threshold light detectors

    International Nuclear Information System (INIS)

    Stark, M.; Boslau, O.; Feilitzsch, F.v.; Goldstrass, P.; Jochum, J.; Kemmer, J.; Potzel, W.; Rau, W.

    2005-01-01

    Simultaneous measurement of a temperature signal and scintillation light of a CaWO 4 crystal can be used for background rejection in cryogenic dark matter experiments. In our case the light is measured with a cryogenic detector that consists of a silicon absorber with a superconducting phase transition thermometer. Due to the Neganov-Luke effect the thermal signal is enhanced when a voltage is applied to the silicon absorber. First results with the application of this effect to our low-threshold light detectors will be discussed in this paper

  11. Modifications in the structural and optical properties of nanocrystalline CaWO4 induced by 8 MeV electron beam irradiation

    International Nuclear Information System (INIS)

    Aloysius Sabu, N.; Priyanka, K.P.; Ganesh, Sanjeev; Varghese, Thomas

    2016-01-01

    In this article we report the post irradiation effects in the structural and optical properties of nanocrystalline calcium tungstate synthesized by chemical precipitation and heat treatment. The samples were subjected to different doses of high-energy electron beam obtained from an 8 MeV Microton. Investigations using X-ray diffraction, scanning electron microscopy and Raman spectra confirmed changes in particle size and structural parameters. However, no phase change was detected for irradiated samples. The stretching/compressive strain caused by high energy electrons is responsible for the slight shift in the XRD peaks of irradiated samples. Modifications in the morphology of different samples were confirmed by scanning electron microscopy. Ultraviolet-visible absorption studies showed variations in the optical band gap (4.08–4.25 eV) upon electron-beam irradiation. New photoluminescence behaviour in electron beam irradiated nanocrystalline CaWO 4 was evidenced. A blue shift of the PL peak with increase in intensity was observed in all the irradiated samples. - Highlights: • Calcium tungstate nanocrystals are synthesized by simple chemical precipitation method. • Electron beam induced modifications in the structural and optical properties are investigated. • New photoluminescence behaviour is evidenced due to beam irradiation.

  12. Simulation of light collection in calcium tungstate scintillation detectors

    Directory of Open Access Journals (Sweden)

    F. A. Danevich

    2015-12-01

    Full Text Available Due to high operational properties, the oxide scintillators are perspective for cryogenic scintillation experiments with aim of study rare nuclear processes. In order to optimize light yield and the energy resolution we performed calculations of the efficiency of light collection for different geometries of scintillation detector with CaWO4 crystal by Monte-Carlo method using Litrani, Geant4 and Zemax packages. The calculations were compared with experimental data in the same configurations, depending on the crystal shape, surface treatment, material and shape of the reflector and presence of optical contact. The best results were obtained with crystals shaped as the right prism with triangle base, with completely diffused surfaces, using mirror reflector shaped as a truncated cone. Simulations by using Litrani have shown the best agreement with experimental results.

  13. Gamma camera system with composite solid state detector

    International Nuclear Information System (INIS)

    Gerber, M.S.; Miller, D.W.

    1977-01-01

    A composite solid-state detector is described for utilization within gamma cameras. The detector's formed of an array of detector crystals, the opposed surfaces of each of which are formed incorporating an impedance-derived configuration for determining one coordinate of the location of discrete impinging photons upon the detector. A combined read-out for all detectors within the composite array is achieved through a row and column interconnection of the impedance configurations. Utilizing the read-outs for respective sides of the discrete crystals, a resultant time-constant characteristic for the composite detector crystal array remains essentially that of individual crystal detectors

  14. A Cryogenic Detector Characterization Facility in the Shallow Underground Laboratory at the Technical University of Munich

    Science.gov (United States)

    Langenkämper, A.; Defay, X.; Ferreiro Iachellini, N.; Kinast, A.; Lanfranchi, J.-C.; Lindner, E.; Mancuso, M.; Mondragón, E.; Münster, A.; Ortmann, T.; Potzel, W.; Schönert, S.; Strauss, R.; Ulrich, A.; Wawoczny, S.; Willers, M.

    2018-04-01

    The Physics Department of the Technical University of Munich operates a shallow underground detector laboratory in Garching, Germany. It provides ˜ 160 {m^2} of laboratory space which is shielded from cosmic radiation by ˜ 6 m of gravel and soil, corresponding to a shielding of ˜ 15 {m.w.e.} . The laboratory also houses a cleanroom equipped with work- and wetbenches, a chemical fumehood as well as a spin-coater and a mask-aligner for photolithographic processing of semiconductor detectors. Furthermore, the shallow underground laboratory runs two high-purity germanium detector screening stations, a liquid argon cryostat and a ^3 He-^4 He dilution refrigerator with a base temperature of ≤ 12-14 mK . The infrastructure provided by the shallow laboratory is particularly relevant for the characterization of CaWO_4 target crystals for the CRESST-III experiment, detector fabrication and assembly for rare event searches. Future applications of the laboratory include detector development in the framework of coherent neutrino nucleus scattering experiments (ν -cleus) and studying its potential as a site to search for MeV-scale dark matter with gram-scale cryogenic detectors.

  15. Possibility of adjusting the photoluminescence spectrum of Ca scheelites to the emission spectrum of incandescent lamps: [ nCaWO4-(1- n)CaMoO4]: Eu3+ solid solutions

    Science.gov (United States)

    Bakovets, V. V.; Zolotova, E. S.; Antonova, O. V.; Korol'kov, I. V.; Yushina, I. V.

    2016-12-01

    The specific features of the photoluminescence of [ nCaWO4-(1- n)CaMoO4]:Eu3+ solid solutions with the scheelite structure are examined using X-ray phase analysis and photoluminescence, Raman scattering, and diffuse reflectance spectroscopy. The studied features are associated with a change in the long- and short-range orders of the crystal lattice upon variations in the composition of solutions in the range n = 0-1.0 (with a pitch of 0.2) at a concentration of red photoluminescence activator Eu3+ of 2 mol %. The mechanism of the modification of photoluminescence of solid solutions upon variations in their composition has been discussed. Anomalies in the variations in parameters of the crystal lattice, its short-range order, and luminescence spectra have been observed in the transition from pure compounds CaMoO4:Eu3+ and CaWO4:Eu3+ to solutions; the concentration of Eu3+ ions in the centrosymmetric localization increases (decreases) in the transition from the molybdate (tungstate). It has been demonstrated that the spectral radiant emittance of solid solution [0.4CaWO4-0.6CaMoO4]:Eu3+ (2 mol %) is the closest to that of an incandescent lamp.

  16. Direct dark matter search with the CRESST-III experiment - status and perspectives

    Science.gov (United States)

    Willers, M.; Angloher, G.; Bento, A.; Bucci, C.; Canonica, L.; Defay, X.; Erb, A.; Feilitzsch, F. v.; Ferreiro Iachellini, N.; Gütlein, A.; Gorla, P.; Hauff, D.; Jochum, J.; Kiefer, M.; Kluck, H.; Kraus, H.; Lanfranchi, J.-C.; Loebell, J.; Mancuso, M.; Münster, A.; Pagliarone, C.; Petricca, F.; Potzel, W.; Pröbst, F.; Puig, R.; Reindl, F.; Schäffner, K.; Schieck, J.; Schönert, S.; Seidel, W.; Stahlberg, M.; Stodolsky, L.; Strandhagen, C.; Strauss, R.; Tanzke, A.; Trinh Thi, H. H.; Türkoǧlu, C.; Uffinger, M.; Ulrich, A.; Usherov, I.; Wawoczny, S.; Wüstrich, M.; Zöller, A.

    2017-09-01

    The CRESST-III experiment, located in the Gran Sasso underground laboratory (LNGS, Italy), aims at the direct detection of dark matter (DM) particles. Scintillating CaWO4 crystals operated as cryogenic detectors are used as target material for DM-nucleus scattering. The simultaneous measurement of the phonon signal from the CaWO4 crystal and of the emitted scintillation light in a separate cryogenic light detector is used to discriminate backgrounds from a possible dark matter signal. The experiment aims to significantly improve the sensitivity for low-mass (≲ 5-10 GeV/c2) DM particles by using optimized detector modules with a nuclear recoil-energy threshold ≲ 100 eV. The current status of the experiment as well as projections of the sensitivity for spin-independent DM-nucleon scattering will be presented.

  17. Impact of geometry on light collection efficiency of scintillation detectors for cryogenic rare event searches

    International Nuclear Information System (INIS)

    Danevich, F.A.; Kobychev, V.V.; Kobychev, R.V.; Kraus, H.; Mikhailik, V.B.; Mokina, V.M.; Solsky, I.M.

    2014-01-01

    Simulations of photon propagation in scintillation detectors were performed with the aim to find the optimal scintillator geometry, surface treatment, and shape of external reflector in order to achieve maximum light collection efficiency for detector configurations that avoid direct optical coupling, a situation that is commonly found in cryogenic scintillating bolometers in experimental searches for double beta decay and dark matter. To evaluate the light collection efficiency of various geometrical configurations we used the ZEMAX ray-tracing software. It was found that scintillators in the shape of a triangular prism with an external mirror shaped as truncated cone gives the highest light collection efficiency. The results of the simulations were confirmed by carrying out measurements of the light collection efficiencies of CaWO 4 crystal scintillators. A comparison of simulated and measured values of light output shows good agreement

  18. A first principle approach for encapsulated type composite detectors

    International Nuclear Information System (INIS)

    Kshetri, R

    2012-01-01

    A first principle approach is presented for modeling a composite detector consisting of several high-purity germanium detector modules. Without making assumptions, if we consider the full energy peak counts from single and multiple detector module interactions, and the decomposition of background counts to counts corresponding to the escaping γ-rays and counts for γ-rays which could be recovered in addback mode, it is observed that the addback mode of a composite detector could be described in terms of four probability amplitudes only. Expressions for peak-to-total and peak-to-background ratios are obtained. Considering details of the scattering and absorption processes in a composite detector, a formalism is introduced for understanding the probability amplitudes. Detailed investigation has been performed on the effect of shape and size of composite detectors on peak-to-total and peak-to-background ratios. In accordance with isoperimetric inequality for hexagonal shapes, we have discussed about the optimal design of detector layout for extremely large values of detector modules. Using experimental data on relative single crystal efficiency, addback factor and peak-to-total ratio at 1332 keV for cluster detector, the peak-to-total and peak-to-background ratios have been calculated for several composite detectors.

  19. Metal-semiconductor, composite radiation detectors

    International Nuclear Information System (INIS)

    Orvis, W.J.; Yee, J.H.; Fuess, D.

    1992-12-01

    In 1989, Naruse and Hatayama of Toshiba published a design for an increased efficiency x-ray detector. The design increased the efficiency of a semiconductor detector by interspersing layers of high-z metal within it. Semiconductors such as silicon make good, high-resolution radiation detectors, but they have low efficiency because they are low-z materials (z = 14). High-z metals, on the other hand, are good absorbers of high-energy photons. By interspersing high-z metal layers with semiconductor layers, Naruse and Hatayama combined the high absorption efficiency of the high-z metals with the good detection capabilities of a semiconductor. This project is an attempt to use the same design to produce a high-efficiency, room temperature gamma ray detector. By their nature, gamma rays require thicker metal layers to efficiently absorb them. These thicker layers change the behavior of the detector by reducing the resolution, compared to a solid state detector, and shifting the photopeak by a predictable amount. During the last year, the authors have procured and tested a commercial device with operating characteristics similar to those of a single layer of the composite device. They have modeled the radiation transport in a multi-layered device, to verify the initial calculations of layer thickness and composition. They have modeled the electrostatic field in different device designs to locate and remove high-field regions that can cause device breakdown. They have fabricated 14 single layer prototypes

  20. Synthesis and characterization of rare-earth-doped calcium tungstate nanocrystals

    Science.gov (United States)

    Suneeta, P.; Rajesh, Ch.; Ramana, M. V.

    2018-02-01

    In this paper, we report synthesis and characterization of rare-earth-ion-doped calcium tungstate (CaWO4) nanocrystals (NCs). Rare-earth ions, such as gadolinium (Gd), neodymium (Nd), praseodymium (Pr), samarium (Sm) and holmium (Ho), were successfully doped in the CaWO4 NCs by changing the synthesis conditions. The adopted synthesis route was found to be fast and eco-friendly. Structural characterizations, such as X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and compositional analysis, were performed using energy dispersive analysis of X-rays (EDAX) on as-synthesized NCs. The results indicate the size of the NCs ranging between 47 to 68nm and incorporation of rare-earth ions in CaWO4 NCs.

  1. Primary Cosmic Rays Composition: Simulations and Detector Design

    International Nuclear Information System (INIS)

    Supanitsky, D.; Etchegoyen, A.; Medina, C.; Medina-Tanco, G.; Gomez Berisso, M.

    2007-01-01

    The Pierre Auger Observatory is a hybrid detector system for the detection of very high energy cosmic rays. A most difficult and important problem in these studies is the determination of the primary cosmic ray composition for which muon content in air showers appears to be one of the best parameters to discriminate between different composition types.Although the Pierre Auger surface detectors, which consist of water Cherenkov tanks, are sensitive to muon content they are not able to measure the number of muons directly. In this work we study using simulations the information that can be gained by adding muon detectors to the Auger surface detectors. We consider muon counters with two alternative areas

  2. Geometric optimization of a neutron detector based on a lithium glass–polymer composite

    Energy Technology Data Exchange (ETDEWEB)

    Mayer, M., E-mail: mike.f.mayer@gmail.com [Department of Mechanical and Nuclear Engineering, The Pennsylvania State University, University Park, PA 16802 (United States); Nattress, J. [Department of Mechanical and Nuclear Engineering, The Pennsylvania State University, University Park, PA 16802 (United States); Trivelpiece, C. [Materials Research Institute, The Pennsylvania State University, University Park, PA 16802 (United States); Jovanovic, I. [Department of Mechanical and Nuclear Engineering, The Pennsylvania State University, University Park, PA 16802 (United States)

    2015-06-01

    We report on the simulation and optimization of a neutron detector based on a glass–polymer composite that achieves high gamma rejection. Lithium glass is embedded in polyvinyltoluene in three geometric forms: disks, rods, and spheres. Optimal shape, geometric configuration, and size of the lithium glass fragments are determined using Geant4 simulations. All geometrical configurations maintain an approximate 7% glass to polymer mass ratio. Results indicate a 125-mm diameter as the optimal detector size for initial prototype design achieving a 10% efficiency for the thermalization of incident fission neutrons from {sup 252}Cf. The geometrical features of a composite detector are shown to have little effect on the intrinsic neutron efficiency, but a significant effect on the gamma rejection is observed. The sphere geometry showed the best overall performance with an intrinsic neutron efficiency of approximately 6% with a gamma rejection better than 10{sup −7} for 280-μm diameter spheres. These promising results provide a motivation for prototype composite detector development based on the simulated designs. - Highlights: • Composite polymer–lithium glass scintillation detector is simulated. • Polymer is considered to be non-scintillating in the simulation. • Three forms of lithium glass are considered: disks, rods, and spheres. • Glass shape has a small effect on neutron efficiency. • Glass shape has a significant effect on gamma rejection.

  3. Hydrothermal synthesis and luminescence of CaMO4:RE3+ (M=W, Mo; RE=Eu, Tb) submicro-phosphors

    International Nuclear Information System (INIS)

    Lei Fang; Yan Bing

    2008-01-01

    Submicrometer crystalline CaMO 4 :RE 3+ (M=W, Mo; RE=Eu, Tb) phosphors with a sheelite structure have been synthesized via the hydrothermal process, which were characterized by X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), X-ray-excited luminescence (XEL), UV-vis diffuse reflectance spectra (UV-vis DRS) and scanning electron microscopy (SEM), respectively. The XRD patterns show that both CaWO 4 and CaMoO 4 have the same structure with space group I41/a. The SEM images indicate that the optimal hydrothermal temperature is 120 deg. C for the particles that aggregate with the increase of temperature. The bands ranging from 380 to 510 nm in the XEL spectra of CaWO 4 :Eu 3+ can be attributed to the charge transfer state from the excited 2p orbits of O 2- to the empty orbits of the central W 6+ of the tungstate groups. The comparison between photoluminescent lifetimes and quantum efficiencies of the two phosphors was also investigated in detail. - Graphical abstract: Submicro-crystalline Eu 3+ -activated tungstate CaWO 4 :RE 3+ phosphors with a sheelite structure have been synthesized via the hydrothermal process; the morphology was determined from the hydrothermal temperature. Scanning electron microscopy (SEM) images show that CaWO 4 :Eu 3+ exhibits spherical particles, which can be controlled by the reaction parameters

  4. Detector Simulations with DD4hep

    Science.gov (United States)

    Petrič, M.; Frank, M.; Gaede, F.; Lu, S.; Nikiforou, N.; Sailer, A.

    2017-10-01

    Detector description is a key component of detector design studies, test beam analyses, and most of particle physics experiments that require the simulation of more and more different detector geometries and event types. This paper describes DD4hep, which is an easy-to-use yet flexible and powerful detector description framework that can be used for detector simulation and also extended to specific needs for a particular working environment. Linear collider detector concepts ILD, SiD and CLICdp as well as detector development collaborations CALICE and FCal have chosen to adopt the DD4hep geometry framework and its DDG4 pathway to Geant4 as its core simulation and reconstruction tools. The DDG4 plugins suite includes a wide variety of input formats, provides access to the Geant4 particle gun or general particles source and allows for handling of Monte Carlo truth information, eg. by linking hits and the primary particle that caused them, which is indispensable for performance and efficiency studies. An extendable array of segmentations and sensitive detectors allows the simulation of a wide variety of detector technologies. This paper shows how DD4hep allows to perform complex Geant4 detector simulations without compiling a single line of additional code by providing a palette of sub-detector components that can be combined and configured via compact XML files. Simulation is controlled either completely via the command line or via simple Python steering files interpreted by a Python executable. It also discusses how additional plugins and extensions can be created to increase the functionality.

  5. Full energy peak efficiency of composite detectors for high energy gamma-rays

    International Nuclear Information System (INIS)

    Kshetri, Ritesh

    2015-01-01

    Experiments involving radioactive beams demand high detection efficiencies. One of the ways to obtain high detection efficiency without deteriorating the energy resolution or timing characteristics is the use of composite detectors which are composed of standard HPGe crystals arranged in a compact way. Two simplest composite detectors are the clover and cluster detectors. The TRIUMF-ISAC Gamma-Ray Escape-Suppressed Spectrometer (TIGRESS) comprises of 16 large volume, 32-fold segmented HPGe clover detectors, where each detector is shielded by a 20-fold segmented escape suppression shield (ESS)

  6. Detector simulations with DD4hep

    CERN Document Server

    AUTHOR|(SzGeCERN)668365; Frank, Markus; Gaede, Frank-Dieter; Lu, Shaojun; Nikiforou, Nikiforos; Sailer, Andre

    2017-01-01

    Detector description is a key component of detector design studies, test beam analyses, and most of particle physics experiments that require the simulation of more and more different detector geometries and event types. This paper describes DD4hep, which is an easy-to-use yet flexible and powerful detector description framework that can be used for detector simulation and also extended to specific needs for a particular working environment. Linear collider detector concepts ILD, SiD and CLICdp as well as detector development collaborations CALICE and FCal have chosen to adopt the DD4hep geometry framework and its DDG4 pathway to Geant4 as its core simulation and reconstruction tools. The DDG4 plugins suite includes a wide variety of input formats, provides access to the Geant4 particle gun or general particles source and allows for handling of Monte Carlo truth information, e.g. by linking hits and the primary particle that caused them, which is indispensable for performance and efficiency studies. An extend...

  7. Enhanced orange-red emission by using Mo codoped in Ba2CaWO6: Eu3+, Li+ phosphor under near UV excitation

    International Nuclear Information System (INIS)

    Sun, Xiaoyuan; Hao, Zhendong; Li, Chunjie; He, Xiaoguang; Qi, Haiyan; Yu, Lijun; Luo, Yongshi; Zhang, Jiahua; Gao, Jiwei; Zhong, Ruixia

    2013-01-01

    The orange-red emitting phosphors Ba 2 Ca 0.9 Mo x W 1−x O 6 :Eu 3+ 0.05 , Li + 0.05 (x=0, 0.05, 0.1, 0.15, 0.2, 0.25, 0.5, 0.75, and 1.0) and Ba 2 Ca 1−2y Mo 0.2 W 0.8 O 6 :Eu 3+ y , Li + y (y=0.03, 0.05, 0.07, 0.1, and 0.15) were synthesized. The crystalline structure and photoluminescence properties of these phosphors were described. The strong orange-red emission of Eu 3+ ( 5 D 0 — 7 F 1 transition) at around 593 nm was observed. Addition of Mo strongly enhances the charge transfer band absorption in the near ultraviolet region that corresponds to near ultraviolet white light emitting diode. The dependence of photoluminescence intensities on Eu 3+ concentrations with optimal Mo concentration under 400 nm excitation was studied. The phosphor is considered to be a promising orange-red emitting phosphor for near ultraviolet GaN-based white light emitting diode. - Highlights: ► The samples form solid solutions when Mo is added into Ba 2 CaWO 6 : Eu 3+ , Li + phosphors. ► Addition of Mo in Ba 2 CaWO 6 : Eu 3+ , Li + shifts the PLE spectra maximum from UV region to near UV region. ► In Ba 2 CaMo x W 1−x O 6 :Eu 3+ , Li + , the most efficient concentrations occur at 0.1 and 0.2 for Eu and Mo.

  8. A Geant4 simulation package for the TASISpec experimental detector setup

    Energy Technology Data Exchange (ETDEWEB)

    Sarmiento, L.G., E-mail: lgsarmientop@unal.edu.co [Universidad Nacional de Colombia, Bogota D.C. 111321 (Colombia); Lund University, S-22100 Lund (Sweden); Andersson, L.-L. [University of Liverpool, Oliver Lodge Laboratory, Liverpool L69 7ZE (United Kingdom); Rudolph, D. [Lund University, S-22100 Lund (Sweden)

    2012-03-01

    The experimental detector setup TASISpec (TA SCA in Small Image mode Spectroscopy) comprises composite Ge- and highly segmented Si-detectors. The setup is constructed to provide multi-coincidence spectroscopic data between {gamma}-rays, X-rays, conversion electrons, fission fragments, and {alpha}-particles for heavy and superheavy elements (Z{>=}100). The full array has been virtually constructed using the Geant4 simulation toolkit. The simulations will not only be used to explore the possibilities of the detector setup itself. More important, however, they will also shed light on the nuclear structure of the heaviest elements. This can be done by comparing the simulated detector response of complex decay modes with the experimental data. Such an iterative or 'self-consistent' way to understand experimental observables will provide more reliability when disentangling the data and deducing experimental decay schemes.

  9. Response function of an HPGe detector simulated through MCNP 4A varying the density and chemical composition of the matrix

    International Nuclear Information System (INIS)

    Leal A, B.; Mireles G, F.; Quirino T, L.; Pinedo, J.L.

    2005-01-01

    In the area of the Radiological Safety it is required of a calibrated detection system in energy and efficiency for the determination of the concentration in activity in samples that vary in chemical composition and by this in density. The area of Nuclear Engineering requires to find the grade of isotopic enrichment of the uranium of the Sub-critic Nuclear Chicago 9000 Mark. Given the experimental importance that has the determination from the curves of efficiency to the effects of establishing the quantitative results, is appealed to the simulation of the response function of the detector used in the Regional Center of Nuclear Studies inside the range of energy of 80 keV to 1400 keV varying the density of the matrix and the chemical composition by means of the application of the Monte Carlo code MCNP-4A. The obtained results in the simulation of the response function of the detector show a grade of acceptance in the range from 500 to 1400 keV energy, with a smaller percentage discrepancy to 10%, in the range of low energy that its go from 59 to 400 keV, the percentage discrepancy varies from 17% until 30%, which is manifested in the opposing isotopic relationship for 5 fuel rods of the Sub critic nuclear assemble. (Author)

  10. Polymer-Ceramic Composite Materials for Pyroelectric Infrared Detectors: An Overview

    Science.gov (United States)

    Aggarwal, M. D; Currie, J. R.; Penn, B. G.; Batra, A. K.; Lal, R. B.

    2007-01-01

    Ferroelectrics:Polymer composites can be considered an established substitute for conventional electroceramics and ferroelectric polymers. The composites have a unique blend of polymeric properties such as mechanical flexibility, high strength, formability, and low cost, with the high electro-active properties of ceramic materials. They have attracted considerable interest because of their potential use in pyroelectric infrared detecting devices and piezoelectric transducers. These flexible sensors and transducers may eventually be useful for their health monitoring applications for NASA crew launch vehicles and crew exploration vehicles being developed. In the light of many technologically important applications in this field, it is worthwhile to present an overview of the pyroelectric infrared detector theory, models to predict dielectric behavior and pyroelectric coefficient, and the concept of connectivity and fabrication techniques of biphasic composites. An elaborate review of Pyroelectric-Polymer composite materials investigated to date for their potential use in pyroelectric infrared detectors is presented.

  11. Focusing of a new germanium counter type : the composite detector. Uses of the TREFLE detector in the EUROGAM multidetector

    International Nuclear Information System (INIS)

    Han, L.

    1995-05-01

    The aim of this thesis is the development of new types of germanium detectors: the composite detectors. Two types of prototypes are then conceived: the stacked planar detector (EDP) and the assembly of coaxial diodes (TREFLE). They are designed for the multidetector EUROGAM destined to the research of nuclear structure at high angular momentum. The four planar diodes of EDP detector were of 7 cm diameter and of 15 to 20 mm thick. The difference between the calculated and measured photopic efficiency is observed. The importance of surface channel induces a weak resistance of neutron damages. The sputtering method for the surface treatment reducing the germanium dead layer as well as a rule of selection concerning the impurity concentration and the thickness of crystal is helpful for the later production of germanium detector. The CLOVER detector consist of for mean size crystals in the same cryostat. The photopic efficiency is much larger than that of the greatest monocrystal detector. And the granulation of composite detector allowed the Doppler broadening correction of gamma ray observed in the nuclear reaction where the recoil velocity is very high. This new type of detector enable the linear polarization measurement of gamma ray. Twenty-four CLOVER detector are actually mounted in the EUROGAM array. The characteristics measured in source as well as in beam, reported in this thesis, meet exactly the charge account. (author). 47 refs., 61 figs., 18 tabs

  12. Measurement of atmospheric neutrino composition with the IMB-3 detector

    International Nuclear Information System (INIS)

    Casper, D.; Becker-Szendy, R.; Bratton, C.B.; Cady, D.R.; Claus, R.; Dye, S.T.; Gajewski, W.; Goldhaber, M.; Haines, T.J.; Halverson, P.G.; Jones, T.W.; Kielczewska, D.; Kropp, W.R.; Learned, J.G.; LoSecco, J.M.; McGrew, C.; Matsuno, S.; Matthews, J.; Mudan, M.S.; Price, L.; Reines, F.; Schultz, J.; Sinclair, D.; Sobel, H.W.; Stone, J.L.; Sulak, L.R.; Svoboda, R.; Thornton, G.; van der Velde, J.C.; The University of Michigan, Ann Arbor, Michigan 48109 Brookhaven National; Laboratory, Upton, New York 11973; Boston University, Boston, Massachusetts 02215; The University of Hawaii, Honolulu, Hawaii 96822 University College, London, WC1E F6BT, United Kingdom; Warsaw University, Warsaw, Poland; Cleveland State University, Cleveland, Ohio 44115; The University of Notre Dame, Notre Dame, Indiana 46556; Lousiana State University, Baton Rouge, Lousisiana 70803; The University of Maryland, College Park, Maryland 20742)

    1991-01-01

    The atmospheric neutrino flux is measured using a 3.4-kt yr exposure of the IMB-3 detector. Single-ring events are classified as showering or nonshowering using the geometry of the Cerenkov pattern. A simulation of neutrino interactions and three models of atmospheric neutrino production are used to predict the composition of the sample. Showering-nonshowering character is strongly correlated with the flavor of the neutrino parent. In the lepton momentum range p<1500 MeV/c, we find that nonshowering events comprise [41±3±2syst]% of the total. The fraction expected is [51±5(syst)]%

  13. Response function of an HPGe detector simulated through MCNP 4A varying the density and chemical composition of the matrix; Funcion respuesta de un detector HPGe simulada mediante MCNP 4A variando la densidad y composicion quimica de la matriz

    Energy Technology Data Exchange (ETDEWEB)

    Leal A, B.; Mireles G, F.; Quirino T, L.; Pinedo, J.L. [Universidad Autonoma de Zacatecas, Zacatecas (Mexico)]. e-mail: bleal79@yahoo.com.mx

    2005-07-01

    In the area of the Radiological Safety it is required of a calibrated detection system in energy and efficiency for the determination of the concentration in activity in samples that vary in chemical composition and by this in density. The area of Nuclear Engineering requires to find the grade of isotopic enrichment of the uranium of the Sub-critic Nuclear Chicago 9000 Mark. Given the experimental importance that has the determination from the curves of efficiency to the effects of establishing the quantitative results, is appealed to the simulation of the response function of the detector used in the Regional Center of Nuclear Studies inside the range of energy of 80 keV to 1400 keV varying the density of the matrix and the chemical composition by means of the application of the Monte Carlo code MCNP-4A. The obtained results in the simulation of the response function of the detector show a grade of acceptance in the range from 500 to 1400 keV energy, with a smaller percentage discrepancy to 10%, in the range of low energy that its go from 59 to 400 keV, the percentage discrepancy varies from 17% until 30%, which is manifested in the opposing isotopic relationship for 5 fuel rods of the Sub critic nuclear assemble. (Author)

  14. Advanced Multilayer Composite Heavy-Oxide Scintillator Detectors for High Efficiency Fast Neutron Detection

    Science.gov (United States)

    Ryzhikov, Vladimir D.; Naydenov, Sergei V.; Pochet, Thierry; Onyshchenko, Gennadiy M.; Piven, Leonid A.; Smith, Craig F.

    2018-01-01

    We have developed and evaluated a new approach to fast neutron and neutron-gamma detection based on large-area multilayer composite heterogeneous detection media consisting of dispersed granules of small-crystalline scintillators contained in a transparent organic (plastic) matrix. Layers of the composite material are alternated with layers of transparent plastic scintillator material serving as light guides. The resulting detection medium - designated as ZEBRA - serves as both an active neutron converter and a detection scintillator which is designed to detect both neutrons and gamma-quanta. The composite layers of the ZEBRA detector consist of small heavy-oxide scintillators in the form of granules of crystalline BGO, GSO, ZWO, PWO and other materials. We have produced and tested the ZEBRA detector of sizes 100x100x41 mm and greater, and determined that they have very high efficiency of fast neutron detection (up to 49% or greater), comparable to that which can be achieved by large sized heavy-oxide single crystals of about Ø40x80 cm3 volume. We have also studied the sensitivity variation to fast neutron detection by using different types of multilayer ZEBRA detectors of 100 cm2 surface area and 41 mm thickness (with a detector weight of about 1 kg) and found it to be comparable to the sensitivity of a 3He-detector representing a total cross-section of about 2000 cm2 (with a weight of detector, including its plastic moderator, of about 120 kg). The measured count rate in response to a fast neutron source of 252Cf at 2 m for the ZEBRA-GSO detector of size 100x100x41 mm3 was 2.84 cps/ng, and this count rate can be doubled by increasing the detector height (and area) up to 200x100 mm2. In summary, the ZEBRA detectors represent a new type of high efficiency and low cost solid-state neutron detector that can be used for stationary neutron/gamma portals. They may represent an interesting alternative to expensive, bulky gas counters based on 3He or 10B neutron

  15. 4π detector for correlation experiments

    International Nuclear Information System (INIS)

    Thorndike, A.M.

    1975-01-01

    A conceptual design of a 4π detector for ISA-BELLE involves a counter hodoscope with 302 elements and an array of proportional wire chambers with 8950 wires. Such a detector could be used for correlation experiments and measurements of total cross section, as has been done by the Pisa-Stony Brook group at the ISR. (U.S.)

  16. The Inner Detector software moves to Geant4

    CERN Multimedia

    Elsing, M

    2004-01-01

    2004 is a year of change and of several major milestones for the Inner Detector software. The first of these milestones was met in March when a set of test events was successfully processed through Geant4 and afterwards through the full Inner Detector offline software chain. In the picture, a reconstructed single muon event from this test sample is displayed in different projections. Even though this looks almost trivial, it required the successful integration of several new software components besides Geant4 into the Inner Detector code. A new ATLAS wide Detector Description software package called GeoModel has been fully deployed in the Inner Detector as the single source of geometry information for both the simulation and the reconstruction. New code to emulate the digitization for all detectors and a new data model have been put in place to cope with the new simulation input. And finally the two major offline reconstruction packages, namely xKalman and iPatRec, were migrated to use the new Inner Detector ...

  17. Performance of CaSO4:Dy detectors

    International Nuclear Information System (INIS)

    Setti, M.C.; Silva, G.R.; Pela, C.A.; Bruco, J.L.; Borges, J.C.

    2004-01-01

    CaSO 4 :Dy detectors have been used in personal dosimetry. The MRA company recently entered into the market of these detectors. Searching to assure a product quality level that would satisfy its customs most expectancies, MRA programmed several tests to qualify and quantify these detectors main characteristics, before their definitive insertion in the market. Preliminary tests furnished a value of 29,5 ± 1,2 nC for homogeneity and a maximum dispersion of 3 % for linearity . (author)

  18. Development and characterization of a neutron detector based on a lithium glass–polymer composite

    Energy Technology Data Exchange (ETDEWEB)

    Mayer, M.; Nattress, J.; Kukharev, V.; Foster, A.; Meddeb, A. [Department of Mechanical and Nuclear Engineering, The Pennsylvania State University, University Park, PA 16802 (United States); Trivelpiece, C. [Materials Research Institute, The Pennsylvania State University, University Park, PA 16802 (United States); Ounaies, Z. [Department of Mechanical and Nuclear Engineering, The Pennsylvania State University, University Park, PA 16802 (United States); Jovanovic, I., E-mail: ijovanovic@psu.edu [Department of Mechanical and Nuclear Engineering, The Pennsylvania State University, University Park, PA 16802 (United States)

    2015-06-11

    We report on the fabrication and characterization of a neutron scintillation detector based on a Li-glass–polymer composite that utilizes a combination of pulse height and pulse shape discrimination (PSD) to achieve high gamma rejection. In contrast to fast neutron detection in a PSD medium, we combine two scintillating materials that do not possess inherent neutron/gamma PSD properties to achieve effective PSD/pulse height discrimination in a composite material. Unlike recoil-based fast neutron detection, neutron/gamma discrimination can be robust even at low neutron energies due to the high Q-value neutron capture on {sup 6}Li. A cylindrical detector with a 5.05 cm diameter and 5.08 cm height was fabricated from scintillating 1 mm diameter Li-glass rods and scintillating polyvinyltoluene. The intrinsic efficiency for incident fission neutrons from {sup 252}Cf and gamma rejection of the detector were measured to be 0.33% and less than 10{sup −8}, respectively. These results demonstrate the high selectivity of the detector for neutrons and provide motivation for prototyping larger detectors optimized for specific applications, such as detection and event-by-event spectrometry of neutrons produced by fission.

  19. Novel fabrication techniques for low-mass composite structures in silicon particle detectors

    Energy Technology Data Exchange (ETDEWEB)

    Hartman, Neal, E-mail: neal.hartman@cern.ch; Silber, Joseph; Anderssen, Eric; Garcia-Sciveres, Maurice; Gilchriese, Murdock; Johnson, Thomas; Cepeda, Mario

    2013-12-21

    The structural design of silicon-based particle detectors is governed by competing demands of reducing mass while maximizing stability and accuracy. These demands can only be met by fiber reinforced composite laminates (CFRP). As detecting sensors and electronics become lower mass, the motivation to reduce structure as a proportion of overall mass pushes modern detector structures to the lower limits of composite ply thickness, while demanding maximum stiffness. However, classical approaches to composite laminate design require symmetric laminates and flat structures, in order to minimize warping during fabrication. This constraint of symmetry in laminate design, and a “flat plate” approach to fabrication, results in more massive structures. This study presents an approach to fabricating stable and accurate, geometrically complex composite structures by bonding warped, asymmetric, but ultra-thin component laminates together in an accurate tool, achieving final overall precision normally associated with planar structures. This technique has been used to fabricate a prototype “I-beam” that supports two layers of detecting elements, while being up to 20 times stiffer and up to 30% lower mass than comparable, independent planar structures (typically known as “staves”)

  20. Realization of the electrical Sentinel 4 detector integration

    Science.gov (United States)

    Hermsen, M.; Hohn, R.; Skegg, M.; Woffinden, C.; Reulke, R.

    2017-09-01

    The detectors of the Sentinel 4 multi spectral imager are operated in flight at 215K while the analog electronics is operated at ambient temperature. The detector is cooled by means of a radiator. For thermal reasons no active component has been allowed in the cooled area closest to the detector as the passive radiator is restricted in its size. For thermal decoupling of detector and electronics a long distance between detector and electronics is considered ideal as thermal conductivity decreases with the length of the connection. In contradiction a short connection between detector and electronics is ideal for the electronic signals. Only a short connection ensures the signal integrity of both the weak detector output signal but similarly also the clock signals for driving the detector. From a mechanical and thermal point of view the connection requires a certain minimum length. The selected solution serves all these needs but had to approach the limits of what is electrically, mechanically and thermally feasible. In addition, shielding from internal (self distortion) and external distorting signals has to be realized for the connection between FEE(Front End Electronics) and detectors. At the time of the design of the flex it was not defined whether the mechanical structure between FEE and FPA (Focal Plane Assembly) would act as a shielding structure. The physical separation between CCD detector and the Front-end Electronics, the adverse EMI environment in which the instrument will be operated in (the location of the instrument on the satellite is in vicinity to a down-link K-band communication antenna of the S/C) require at least the video output signals to be shielded. Both detectors (a NIR and a UVVIS detector) are sensitive to contamination and difficult to be cleaned in case of any contamination. This brings up extreme cleanliness requirements for the detector in manufacturing and assembly. Effectively the detector has to be kept in an ISO 5 environment and

  1. 4π detector at GANIL

    International Nuclear Information System (INIS)

    Babinet, R.; Cassagnou, Y.; Girard, J.

    1979-01-01

    The preliminary ideas put forward by a group of physicists on a wide geometry (approximately 4π) detector for the multiple detection of light particles at Ganil are summarized. The Diogene project of Saturne II served as a basis for the ideas developed [fr

  2. Metal-semiconductor, composite radiation detectors

    International Nuclear Information System (INIS)

    Orvis, W.J.; Yee, J.H.; Fuess, D.A.

    1991-12-01

    In 1989, Naruse and Hatayama of Toshiba published a design for an increased efficiency x-ray detector. The design increased the efficiency of a semiconductor detector by interspersing layers of high-z metal within it. Semiconductors such as silicon make good, high-resolution radiation detectors, but they have low efficiency because they are low-z materials (z = 14). High-z metals, on the other hand, are good absorbers of high-energy photons. By interspersing high-z metal layers with semiconductor layers, Naruse and Hatayama combined the high absorption efficiency of the high-z metals with good detection capabilities of a semiconductor. This project is an attempt to use the same design to produce a high- efficiency gamma ray detector. By their nature, gamma rays require thicker metal layers to efficiently absorb them. These thicker layers change the behavior of the detector by reducing the resolution, compared to a solid state detector, and shifting the photopeak by a predictable amount. During the last year, we have modeled parts of the detector and have nearly completed a prototype device. 2 refs

  3. The research on noise equivalent quanta and detective quantum efficiency of screen-film system

    International Nuclear Information System (INIS)

    Xie Jingdong; Wang Changyuan; Yuan Yude; Zhang Menglong; Wang Jian; Zheng Hao; Sun Yong

    2002-01-01

    Objective: To examine the noise equivalent quanta (NEQ) and detective quantum efficiency (DQE) of screen-film system. Methods: Green 400 screen-Kodak film and CaWO 4 screen-Fuji film were used in the study. The characteristic curves were obtained by distance method. The square wave technique was employed to determine the modulation transfer function (MTF). The Wiener spectrum (WS) was determined by Fourier analysis on uniformly exposed films. The NEQ and DQE were calculated from the characteristic curve slope, MTF, and WS measurements. Results: (1) The NEQ value of Green 400 screen-Kodak film system was 1.48 x 10 6 mm -2 when the spatial frequency was 0.6 cycles/mm, and it was 0.65 times larger than that of CaWO 4 screen-Fuji film system; The NEQ value of Green 400 screen-Kodak film system was 0.329 x 10 4 mm -2 when the spatial frequency was 4.0 cycles/mm, and it was 1.55 times larger than that of CaWO 4 screen-Fuji film system. (2) The DQE value of Green 400 screen-Kodak film system was 0.224 when the spatial frequency was 0.6 cycles/mm, and it was 1.6 times larger than that of CaWO 4 screen-Fuji film system; The DQE value of Green 400 screen-Kodak film system was 0.052 when the spatial frequency was 4.0 cycles/mm, and it was 3.7 times larger than that of CaWO 4 screen-Fuji film system. Conclusion: The Green 400 Screen-Kodak film system has superior NEQ when the spatial frequency was more than 3.0 cycles/mm and has superior DQE among the total spatial frequency in comparison with CaWO 4 screen-Fuji film system

  4. Detectors for Linear Colliders: Detector design for a Future Electron-Positron Collider (4/4)

    CERN Multimedia

    CERN. Geneva

    2010-01-01

    In this lecture I will discuss the issues related to the overall design and optimization of a detector for ILC and CLIC energies. I will concentrate on the two main detector concepts which are being developed in the context of the ILC. Here there has been much recent progress in developing realistic detector models and in understanding the physics performance of the overall detector concept. In addition, I will discuss the how the differences in the detector requirements for the ILC and CLIC impact the overall detector design.

  5. Calibration of the new composite ''clover'' detector as a Compton polarimeter for the EUROGAM array

    International Nuclear Information System (INIS)

    Jones, P.M.; Beck, F.A.; Butler, P.A.; Duchene, G.; France, G. de; Hannachi, F.; Jones, G.D.

    1995-01-01

    The application of a composite Ge detector to the measurement of the linear polarisation of γ-rays has been investigated. The polarisation sensitivity of this device has been determined over the energy range 197-1368 keV. Comparison to a previous design of a similar detector has been made. (orig.)

  6. A novel iterative energy calibration method for composite germanium detectors

    International Nuclear Information System (INIS)

    Pattabiraman, N.S.; Chintalapudi, S.N.; Ghugre, S.S.

    2004-01-01

    An automatic method for energy calibration of the observed experimental spectrum has been developed. The method presented is based on an iterative algorithm and presents an efficient way to perform energy calibrations after establishing the weights of the calibration data. An application of this novel technique for data acquired using composite detectors in an in-beam γ-ray spectroscopy experiment is presented

  7. A novel iterative energy calibration method for composite germanium detectors

    Energy Technology Data Exchange (ETDEWEB)

    Pattabiraman, N.S.; Chintalapudi, S.N.; Ghugre, S.S. E-mail: ssg@alpha.iuc.res.in

    2004-07-01

    An automatic method for energy calibration of the observed experimental spectrum has been developed. The method presented is based on an iterative algorithm and presents an efficient way to perform energy calibrations after establishing the weights of the calibration data. An application of this novel technique for data acquired using composite detectors in an in-beam {gamma}-ray spectroscopy experiment is presented.

  8. The Karlsruhe 4π barium fluoride detector

    International Nuclear Information System (INIS)

    Wisshak, K.; Guber, K.; Kaeppeler, F.; Krisch, J.; Mueller, H.; Rupp, G.; Voss, F.

    1989-12-01

    A new experimental approach has been implemented for accurate measurements of neutron capture cross sections in the energy range from 5 to 200 keV. The Karlsruhe 4π Barium Fluoride Detector consists of 42 crystals shaped as hexagonal and pentagonal truncated pyramids forming a spherical shell with 10 cm inner radius and 15 cm thickness. All crystals are supplied with reflector and photomultiplier, thus representing independent gamma-ray detectors. Each detector module covers the same solid angle with respect to a gamma-ray source located in the centre. The energy resolution of the 4π detector is 14% at 662 keV and 7% at 2.5 MeV gamma-ray energy, the overall time reslution is 500 ps and the peak efficiency 90% at 1 MeV. The detector allows to register capture cascades with 95% probability above a threshold energy of 2.5 MeV in the sum energy spectrum. Neutrons are produced via the 7 Li(p,n) 7 Be reaction using the pulsed proton beam of a Van de Graaff accelerator. The neutron spectrum can be taylored according to the experimental requirements in an energy range from 5 to 200 keV by choosing appropriate proton energies. A collimated neutron beam is passing through the detector and hits the sample in the centre. The energy of captured neutrons is determined via time of flight, the primary flight path being 77 cm. The combination of short primary flight path, a 10 cm inner radius of the spherical BaF 2 shell, and the low capture cross section of barium allows to discriminate background due to capture of sample scattered neutrons in the scintillator by time of flight, leaving part of the neutron energy range completely undisturbed. (orig./HSI) [de

  9. The 4π neutron detector CARMEN

    Energy Technology Data Exchange (ETDEWEB)

    Ledoux, X., E-mail: Xavier.ledoux@ganil.fr [CEA/DAM/DIF, F-91297 Arpajon (France); GANIL, CEA/DRF-CNRS/IN2P3, Caen, F-14076 France (France); Laborie, J.-M.; Pras, P.; Lantuéjoul-Thfoin, I.; Varignon, C. [CEA/DAM/DIF, F-91297 Arpajon (France)

    2017-02-01

    CARMEN is a 4π neutron detector filled with a gadolinium-loaded liquid scintillator built to measure neutron multiplicity distributions. It is used to study fission and (n,xn) reactions. In addition to neutron multiplicity measurements, CARMEN can be used to measure neutron energy spectra with the time-of-flight technique, thanks to the time properties of the prompt signal. The detector, detection technique and efficiency determination are presented in detail. Two examples are also presented: the measurement of {sup 252}Cf spontaneous fission neutron multiplicity probability distribution and the measurement of the neutron energy spectrum emitted by an Am-Be radioactive source.

  10. The Clover detector

    Energy Technology Data Exchange (ETDEWEB)

    Beck, F A; Byrski, Th; Durien, D; Duchene, G; France, G de; Kharraja, B; Wei, L [Strasbourg-1 Univ., 67 (France). Centre de Recherches Nucleaires; Butler, P; Jones, G; Jones, P [Liverpool Univ. (United Kingdom). Oliver Lodge Lab.; Hannachi, F [Daresbury Lab. (United Kingdom)

    1992-08-01

    The EUROGAM Phase I device is almost running for experiments and new technical developments are in progress for its second phase. For example, a composite Ge detector should enable: a very large photopeak efficiency with good energy and timing resolutions; and, the covering, with Ge, of a large portion of 4{pi}-Str. The Clover detector, proposed by the CRN, Strasbourg, is one of this new generation of Ge detectors. It is currently developed in France by the EUROGAM collaboration. The design, the technical characteristics of the counter and the first results of the prototype tests are discussed in this contribution. (author). 1 ref., 2 tabs., 2 refs.

  11. The potential of Neganov-Luke amplified cryogenic light detectors and the scintillation-light quenching mechanism in CaWO4 single crystals in the context of the dark matter search experiment CRESST-II

    International Nuclear Information System (INIS)

    Roth, Sabine B.

    2013-01-01

    The matter in universe is dominated by currently unknown elementary particles, the dark matter. Within the CRESST collaboration, it is attempted to directly detect dark matter for the first time. The interaction of this unknown kind of matter in the detector material creates phonons and light and allows, thus, for the detection and identification of these unknown particles. Within the present work, a new method for detecting the created light was investigated and a microscopic theory of the light creation in the detector material was developed as well as confirmed by experiments.

  12. Rhodium self-powered detector for monitoring neutron fluence, energy production, and isotopic composition of fuel

    International Nuclear Information System (INIS)

    Sokolov, A.P.; Pochivalin, G.P.; Shipovskikh, Yu.M.; Garusov, Yu.V.; Chernikov, O.G.; Shevchenko, V.G.

    1993-01-01

    The use of self-powered detectors (SPDs) with a rhodium emitter customarily involves monitoring of neutron fields in the core of a nuclear reactor. Since current in an SPD is generated primarily because of the neutron flux, which is responsible for the dynamics of particular nuclear transformations, including fission reactions of heavy isotopes, the detector signal can be attributed unambiguously to energy release at the location of the detector. Computation modeling performed with the KOMDPS package of programs of the current formation in a rhodium SPD along with the neutron-physical processes that occur in the reactor core makes it possible to take account of the effect of the principal factors characterizing the operating conditions and the design features of the fuel channel and the detector, reveal quantitative relations between the generated signal and individual physical parameters, and determine the metrological parameters of the detector. The formation and transport of changed particles in the sensitive part of the SPC is calculated by the Monte Carlo method. The emitter activation, neutron transport, and dynamics of the isotopic composition in the fuel channel containing the SPD are determined by solving the kinetic equation in the multigroup representation of the neutron spectrum, using the discrete ordinate method. In this work the authors consider the operation of a rhodium SPD in a bundle of 49 fuel channels of the RBMK-1000 reactor with a fuel enrichment of 2.4% from the time it is inserted into a fresh channel

  13. 4D tracking with ultra-fast silicon detectors

    Science.gov (United States)

    F-W Sadrozinski, Hartmut; Seiden, Abraham; Cartiglia, Nicolò

    2018-02-01

    The evolution of particle detectors has always pushed the technological limit in order to provide enabling technologies to researchers in all fields of science. One archetypal example is the evolution of silicon detectors, from a system with a few channels 30 years ago, to the tens of millions of independent pixels currently used to track charged particles in all major particle physics experiments. Nowadays, silicon detectors are ubiquitous not only in research laboratories but in almost every high-tech apparatus, from portable phones to hospitals. In this contribution, we present a new direction in the evolution of silicon detectors for charge particle tracking, namely the inclusion of very accurate timing information. This enhancement of the present silicon detector paradigm is enabled by the inclusion of controlled low gain in the detector response, therefore increasing the detector output signal sufficiently to make timing measurement possible. After providing a short overview of the advantage of this new technology, we present the necessary conditions that need to be met for both sensor and readout electronics in order to achieve 4D tracking. In the last section, we present the experimental results, demonstrating the validity of our research path.

  14. Orion, a high efficiency 4π neutron detector

    International Nuclear Information System (INIS)

    Crema, E.; Piasecki, E.; Wang, X.M.; Doubre, H.; Galin, J.; Guerreau, D.; Pouthas, J.; Saint-Laurent, F.

    1990-01-01

    In intermediate energy heavy ion collisions the multiplicity of emitted neutrons is strongly connected to energy dissipation and to impact parameter. We present the 4π detector ORION, a high efficiency liquid scintillator detector which permits to get information on the multiplicity of neutrons measured event-wise and on the spatial distribution of these neutrons [fr

  15. Results obtained with the passive radiation detectors in the ICCHIBAN-4 experiment

    International Nuclear Information System (INIS)

    Bilski, P.; Horwacik, T.

    2005-05-01

    In frame of the InterComparison of Cosmic rays with Heavy Ions Beams at NIRS (ICCHIBAN) organized at the HIMAC accelerator in Chiba several types of the thermoluminescent detectors (TLD), as well as CR-39 track detectors, were exposed. Four different types of TLDs were used: MTS-7 ( 7 LiF:Mg,Ti), MTS-6 ( 6 LiF:Mg,Ti), MCP-7 ( 7 LiF:Mg,Cu,P) and MTT-7 ( 7 LiF:Mg,Ti with changed activator composition. All TLDs were manufactured at the Institute of Nuclear Physics (INP) in Cracow. The detectors were irradiated with various doses of He, C, Ne and Fe ions. Part of exposures were done in unknown conditions, to test measuring capabilities of the detectors. For analyses of these results, the method of obtaining information on ionisation density of an unknown radiation field, which is based on ratios of responses of different LiF detectors, was successfully used. (author)

  16. Focusing of a new germanium counter type : the composite detector. Uses of the TREFLE detector in the EUROGAM multidetector; Mise au point d`un nouveau type de compteur germanium: le detecteur composite. Utilisation du detecteur TREFLE dans le multidetecteur EUROGAM

    Energy Technology Data Exchange (ETDEWEB)

    Han, L

    1995-05-01

    The aim of this thesis is the development of new types of germanium detectors: the composite detectors. Two types of prototypes are then conceived: the stacked planar detector (EDP) and the assembly of coaxial diodes (TREFLE). They are designed for the multidetector EUROGAM destined to the research of nuclear structure at high angular momentum. The four planar diodes of EDP detector were of 7 cm diameter and of 15 to 20 mm thick. The difference between the calculated and measured photopic efficiency is observed. The importance of surface channel induces a weak resistance of neutron damages. The sputtering method for the surface treatment reducing the germanium dead layer as well as a rule of selection concerning the impurity concentration and the thickness of crystal is helpful for the later production of germanium detector. The CLOVER detector consist of for mean size crystals in the same cryostat. The photopic efficiency is much larger than that of the greatest monocrystal detector. And the granulation of composite detector allowed the Doppler broadening correction of gamma ray observed in the nuclear reaction where the recoil velocity is very high. This new type of detector enable the linear polarization measurement of gamma ray. Twenty-four CLOVER detector are actually mounted in the EUROGAM array. The characteristics measured in source as well as in beam, reported in this thesis, meet exactly the charge account. (author). 47 refs., 61 figs., 18 tabs.

  17. Low-temperature relative reflectivity measurements of reflective and scintillating foils used in rare event searches

    Science.gov (United States)

    Langenkämper, A.; Ulrich, A.; Defay, X.; Feilitzsch, F. v.; Lanfranchi, J.-C.; Mondragón, E.; Münster, A.; Oppenheimer, C.; Potzel, W.; Roth, S.; Schönert, S.; Steiger, H.; Trinh Thi, H. H.; Wawoczny, S.; Willers, M.; Zöller, A.

    2018-03-01

    In this work we investigate the reflectivity of highly reflective multilayer polymer foils used in the CRESST experiment. The CRESST experiment searches directly for dark matter via operating scintillating CaWO4 crystals as targets for elastic dark matter-nucleon scattering. In order to suppress background events, the experiment employs the so-called phonon-light technique which is based on the simultaneous measurement of the heat signal in the main CaWO4 target crystal and of the emitted scintillation light with a separate cryogenic light detector. Both detectors are surrounded by a highly reflective and scintillating multilayer polymer foil to increase the light collection efficiency and to veto surface backgrounds. While this study is motivated by the CRESST experiment, the results are also relevant for other rare event searches using scintillating cryogenic bolometers in the field of the search of dark matter and neutrinoless double beta decay (0 νββ). In this work a dedicated experiment has been set up to determine the relative reflectivity at 300 K and 20 K of three multilayer foils ("VM2000", "VM2002", "Vikuiti") produced by the company 3M. The intensity of a light beam reflected off the foil is measured with a CCD camera. The ratio of the intensities at 300 K and 20 K corresponds to the relative reflectivity change. The measurements performed in this work show no variation of the reflectivity with temperature at a level of ∼1%.

  18. The Sentinel-4 detectors: architecture and performance

    Science.gov (United States)

    Skegg, Michael P.; Hermsen, Markus; Hohn, Rüdiger; Williges, Christian; Woffinden, Charles; Levillain, Yves; Reulke, Ralf

    2017-09-01

    The Sentinel-4 instrument is an imaging spectrometer, developed by Airbus under ESA contract in the frame of the joint European Union (EU)/ESA COPERNICUS program. SENTINEL-4 will provide accurate measurements of trace gases from geostationary orbit, including key atmospheric constituents such as ozone, nitrogen dioxide, sulfur dioxide, formaldehyde, as well as aerosol and cloud properties. Key to achieving these atmospheric measurements are the two CCD detectors, covering the wavelengths in the ranges 305 nm to 500 nm (UVVIS) and 750 to 775 nm (NIR) respectively. The paper describes the architecture, and operation of these two CCD detectors, which have an unusually high full-well capacity and a very specific architecture and read-out sequence to match the requirements of the Sentinel- 4 instrument. The key performance aspects and their verification through measurement are presented, with a focus on an unusual, bi-modal dark signal generation rate observed during test.

  19. Heavy ion measurement by chemical detectors

    International Nuclear Information System (INIS)

    Huebner, K.; Erzgraeber, G.; Eichhorn, K.

    1979-02-01

    In testing the applicability of the threshold system polyvinyl alcohol/methyl orange/chloral hydrate/sodium tetraborate to the quantitative detection of single particles, the chemical detector was irradiated with 4 He, 12 C, 18 O, 22 He ions of different LET. Detectors with 4 different borax concentrations (chloral hydrate concentration kept constant) have been irradiated. The dose causing the colour change increased linearly with the borax concentration. For equal borax concentrations this dose increases with increasing LET due to the decreasing G value of the HCl. The fluence ranges measurable with the various detector compositions are given. 4 He and 18 O ion ranges have been determined. The measured depth dose curves have been corrected because the dose is LET-dependent. The experimentally determined ranges are in good agreement with values calculated for the detector material

  20. Light composite mirrors for RICH detectors Production, characterisation and stability tests

    CERN Document Server

    Bellunato, T F; Calvi, M; Chignoli, F; D'Ambrosio, C; Matteuzzi, C; Musy, M; Perego, D L

    2005-01-01

    The production of lightweight composite mirror prototypes suitable for application in Ring Imaging Cherenkov (RICH) detectors is described. The goal is the use of such mirrors whenever material budget is a concern. The manufacturing technique is described in detail, together with the achieved results in terms of optical quality. Several ageing tests have been performed on some of the prototypes. The results of these tests are reported.

  1. Spectroscopic micro-tomography of metallic-organic composites by means of photon-counting detectors

    Czech Academy of Sciences Publication Activity Database

    Pichotka, Martin; Jakůbek, Jan; Vavřík, Daniel

    2015-01-01

    Roč. 10, č. 12 (2015), C12033 ISSN 1748-0221 R&D Projects: GA MŠk(CZ) LO1219 Keywords : micro-tomography * photon-counting detectors * metallic-organic composites Subject RIV: BH - Optics, Masers, Lasers Impact factor: 1.310, year: 2015 http://iopscience.iop.org/article/10.1088/1748-0221/10/12/C12033/pdf

  2. Gd2O3:Eu3+/PPO/POPOP/PS composites for digital imaging radiation detectors

    International Nuclear Information System (INIS)

    Oliveira, J.; Correia, V.; Martins, P.M.; Martins, P.; Lanceros-Mendez, S.; Rocha, J.G.

    2015-01-01

    Polymer-based scintillator composites have been produced by combining polystyrene (PS) and Gd 2 O 3 :Eu 3+ scintillator nanoparticles. Polystyrene has been used since it is a flexible and stable binder matrix, resistant to thermal and light deterioration and with suitable optical properties. Gd 2 O 3 :Eu 3+ has been selected as scintillator material due to its wide band gap, high density and visible light yield. The optical, thermal and electrical characteristics of the composites were studied as a function of filler content, together with their performance as scintillator material. Additionally 1 wt.% of 2,5-diphenyloxazole (PPO) and 0.01 wt.% of 1,4 di[2-(5phenyloxazolyl)]benzene (POPOP) were introduced in the polymer matrix in order to strongly improve light yield, i.e., the measured intensity of the output visible radiation, under X-ray irradiation. Increasing scintillator filler concentration (from 0.25 to 7.5 wt.%) increases scintillator light yield and decreases the optical transparency of the composite. The addition of PPO and POPOP strongly increased the overall transduction performance of the composite due to specific absorption and re-emission processes. It is thus shown that Gd 2 O 3 :Eu 3+ /PPO/POPOP/PS composites with 0.25 wt.% of scintillator content with fluorescence molecules are suitable for the development of innovative large-area X-ray radiation detectors with huge demand from the industries. (orig.)

  3. Simulating response functions and pulse shape discrimination for organic scintillation detectors with Geant4

    Energy Technology Data Exchange (ETDEWEB)

    Hartwig, Zachary S., E-mail: hartwig@psfc.mit.edu [Department of Nuclear Science and Engineering, MIT, Cambridge MA (United States); Gumplinger, Peter [TRIUMF, Vancouver, BC (Canada)

    2014-02-11

    We present new capabilities of the Geant4 toolkit that enable the precision simulation of organic scintillation detectors within a comprehensive Monte Carlo code for the first time. As of version 10.0-beta, the Geant4 toolkit models the data-driven photon production from any user-defined scintillator, photon transportation through arbitrarily complex detector geometries, and time-resolved photon detection at the light readout device. By fully specifying the optical properties and geometrical configuration of the detector, the user can simulate response functions, photon transit times, and pulse shape discrimination. These capabilities enable detector simulation within a larger experimental environment as well as computationally evaluating novel scintillators, detector geometry, and light readout configurations. We demonstrate agreement of Geant4 with the NRESP7 code and with experiments for the spectroscopy of neutrons and gammas in the ranges 0–20 MeV and 0.511–1.274 MeV, respectively, using EJ301-based organic scintillation detectors. We also show agreement between Geant4 and experimental modeling of the particle-dependent detector pulses that enable simulated pulse shape discrimination. -- Highlights: • New capabilities enable the modeling of organic scintillation detectors in Geant4. • Detector modeling of complex scintillators, geometries, and light readout. • Enables particle- and energy-dependent production of scintillation photons. • Provides ability to generate response functions with precise optical physics. • Provides ability to computationally evaluate pulse shape discrimination.

  4. The study of response of wide band gap semiconductor detectors using the Geant4

    Directory of Open Access Journals (Sweden)

    Hussain Riaz

    2014-01-01

    Full Text Available The energy dependence on the intrinsic efficiency, absolute efficiency, full energy peak absolute efficiency and peak-to-total ratio have been studied for various wide band gap semiconductor detectors using the Geant4 based Monte Carlo simulations. The detector thickness of 1-4 mm and the area in 16-100 mm2 range were considered in this work. In excellent agreement with earlier work (Rybka et al., [20], the Geant4 simulated values of detector efficiencies have been found to decrease with incident g-ray energy. Both for the detector thickness and the detector area, the increasing trends have been observed for total efficiency as well as for full-energy peak efficiency in 0.1 MeV-50 MeV range. For Cd1-xZnxTe, the detector response remained insensitive to changes in relative proportions of Zn. For various wide band gap detectors studied in this work, the detection efficiency of TlBr was found highest over the entire range of energy, followed by the HgI2, CdTe, and then by CZT.

  5. Implementation of Surface Detector Option in SCALE SAS4 Shielding Module

    International Nuclear Information System (INIS)

    Broadhead, B.L.; Emmett, M.B.; Tang, J.S.

    1999-01-01

    The Shielding Analysis Sequence No. 4 (SAS4) in the Standardized Cask Analysis and Licensing Evaluation System (SCALE) is designed to aid the novice user in the preparation of detailed three-dimensional models and radiation protection studies of transportation or storage packages containing spent fuel from a nuclear reactor facility. The underlying methodology in these analyses is the Monte Carlo particle-tracking approach as incorporated into the MORSE-SGC computer code. The use of these basic procedures is enhanced via the automatic generation of the biasing parameters in the SAS4 sequence, which dramatically increases the calculational efficiency of most standard shielding problems. Until recently the primary mechanism for dose estimates in SAS4 was the use of point detectors, which were effective for single-dose locations, but inefficient for quantification of dose-rate profiles. This paper describes the implementation of a new surface detector option for SAS4 with automatic discretization of the detector surface into multiple segments or subdetectors. Results from several sample problems are given and discussed

  6. Use of diffusion bonded SS-Al composite material in the development of neutron detectors

    International Nuclear Information System (INIS)

    Alex, Mary; Prasad, K.R.; Pappachan, A.L.; Grover, A.K.; Krishnan, J.; Derose, D.J.; Bhanumurthy, K.; Kale, G.B.

    2005-01-01

    The present paper describes the development of a SS-Al composite plate in-house at BARC by diffusion bonding technique. Details of the several tests carried out on the composite material and the use of the plate in the development of a boron lined neutron chamber for Dhruva reactor control instrumentation has been described. The bonded sample has withstood tensile strength test, leak test and thermal cycling test and the leak rate was observed to be less than 3 x 10 -10 stdcc/sec. The chamber with the composite material has been installed in Dhruva Basket C location and connected to the log rate safety channel. It has been working successfully for the past two years. The use of SS-Al composite material has improved the reliability and long-term performance of the detector. (author)

  7. Improved fission neutron energy discrimination with {sup 4}He detectors through pulse filtering

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Ting, E-mail: ting.zhu@ufl.edu [University of Florida, Gainesville, FL (United States); Liang, Yinong; Rolison, Lucas; Barker, Cathleen; Lewis, Jason; Gokhale, Sasmit [University of Florida, Gainesville, FL (United States); Chandra, Rico [Arktis Radiation Detectors Ltd., Räffelstrasse 11, Zürich (Switzerland); Kiff, Scott [Sandia National Laboratories, CA (United States); Chung, Heejun [Korean Institute for Nuclear Nonproliferation and Control, 1534 Yuseong-daero, Yuseong-gu, Daejeon (Korea, Republic of); Ray, Heather; Baciak, James E.; Enqvist, Andreas; Jordan, Kelly A. [University of Florida, Gainesville, FL (United States)

    2017-03-11

    This paper presents experimental and computational techniques implemented for {sup 4}He gas scintillation detectors for induced fission neutron detection. Fission neutrons are produced when natural uranium samples are actively interrogated by 2.45 MeV deuterium-deuterium fusion reaction neutrons. Fission neutrons of energies greater than 2.45 MeV can be distinguished by their different scintillation pulse height spectra since {sup 4}He detectors retain incident fast neutron energy information. To enable the preferential detection of fast neutrons up to 10 MeV and suppress low-energy event counts, the detector photomultiplier gain is lowered and trigger threshold is increased. Pile-up and other unreliable events due to the interrogating neutron flux and background radiation are filtered out prior to the evaluation of pulse height spectra. With these problem-specific calibrations and data processing, the {sup 4}He detector's accuracy at discriminating fission neutrons up to 10 MeV is improved and verified with {sup 252}Cf spontaneous fission neutrons. Given the {sup 4}He detector's ability to differentiate fast neutron sources, this proof-of-concept active-interrogation measurement demonstrates the potential of special nuclear materials detection using a {sup 4}He fast neutron detection system.

  8. ILC Reference Design Report Volume 4 - Detectors

    CERN Document Server

    Behnke, Ties; Jaros, John; Miyamoto, Akiya; Aarons, Gerald; Abe, Toshinori; Abernathy, Jason; Ablikim, Medina; Abramowicz, Halina; Adey, David; Adloff, Catherine; Adolphsen, Chris; Afanaciev, Konstantin; Agapov, Ilya; Ahn, Jung-Keun; Aihara, Hiroaki; Akemoto, Mitsuo; del Carmen Alabau, Maria; Albert, Justin; Albrecht, Hartwig; Albrecht, Michael; Alesini, David; Alexander, Gideon; Alexander, Jim; Allison, Wade; Amann, John; Amirikas, Ramila; An, Qi; Anami, Shozo; Ananthanarayan, B.; Anderson, Terry; Andricek, Ladislav; Anduze, Marc; Anerella, Michael; Anfimov, Nikolai; Angal-Kalinin, Deepa; Antipov, Sergei; Antoine, Claire; Aoki, Mayumi; Aoza, Atsushi; Aplin, Steve; Appleby, Rob; Arai, Yasuo; Araki, Sakae; Arkan, Tug; Arnold, Ned; Arnold, Ray; Arnowitt, Richard; Artru, Xavier; Arya, Kunal; Aryshev, Alexander; Asakawa, Eri; Asiri, Fred; Asner, David; Atac, Muzaffer; Atoian, Grigor; Attié, David; Augustin, Jean-Eudes; Augustine, David B.; Ayres, Bradley; Aziz, Tariq; Baars, Derek; Badaud, Frederique; Baddams, Nigel; Bagger, Jonathan; Bai, Sha; Bailey, David; Bailey, Ian R.; Baker, David; Balalykin, Nikolai I.; Balbuena, Juan Pablo; Baldy, Jean-Luc; Ball, Markus; Ball, Maurice; Ballestrero, Alessandro; Ballin, Jamie; Baltay, Charles; Bambade, Philip; Ban, Syuichi; Band, Henry; Bane, Karl; Banerjee, Bakul; Barbanotti, Serena; Barbareschi, Daniele; Barbaro-Galtieri, Angela; Barber, Desmond P.; Barbi, Mauricio; Bardin, Dmitri Y.; Barish, Barry; Barklow, Timothy L.; Barlow, Roger; Barnes, Virgil E.; Barone, Maura; Bartels, Christoph; Bartsch, Valeria; Basu, Rahul; Battaglia, Marco; Batygin, Yuri; Baudot, Jerome; Baur, Ulrich; Elwyn Baynham, D.; Beard, Carl; Bebek, Chris; Bechtle, Philip; Becker, Ulrich J.; Bedeschi, Franco; Bedjidian, Marc; Behera, Prafulla; Bellantoni, Leo; Bellerive, Alain; Bellomo, Paul; Bentson, Lynn D.; Benyamna, Mustapha; Bergauer, Thomas; Berger, Edmond; Bergholz, Matthias; Beri, Suman; Berndt, Martin; Bernreuther, Werner; Bertolini, Alessandro; Besancon, Marc; Besson, Auguste; Beteille, Andre; Bettoni, Simona; Beyer, Michael; Bhandari, R.K.; Bharadwaj, Vinod; Bhatnagar, Vipin; Bhattacharya, Satyaki; Bhattacharyya, Gautam; Bhattacherjee, Biplob; Bhuyan, Ruchika; Bi, Xiao-Jun; Biagini, Marica; Bialowons, Wilhelm; Biebel, Otmar; Bieler, Thomas; Bierwagen, John; Birch, Alison; Bisset, Mike; Biswal, S.S.; Blackmore, Victoria; Blair, Grahame; Blanchard, Guillaume; Blazey, Gerald; Blue, Andrew; Blümlein, Johannes; Boffo, Christian; Bohn, Courtlandt; Boiko, V.I.; Boisvert, Veronique; Bondarchuk, Eduard N.; Boni, Roberto; Bonvicini, Giovanni; Boogert, Stewart; Boonekamp, Maarten; Boorman, Gary; Borras, Kerstin; Bortoletto, Daniela; Bosco, Alessio; Bosio, Carlo; Bosland, Pierre; Bosotti, Angelo; Boudry, Vincent; Boumediene, Djamel-Eddine; Bouquet, Bernard; Bourov, Serguei; Bowden, Gordon; Bower, Gary; Boyarski, Adam; Bozovic-Jelisavcic, Ivanka; Bozzi, Concezio; Brachmann, Axel; Bradshaw, Tom W.; Brandt, Andrew; Brasser, Hans Peter; Brau, Benjamin; Brau, James E.; Breidenbach, Martin; Bricker, Steve; Brient, Jean-Claude; Brock, Ian; Brodsky, Stanley; Brooksby, Craig; Broome, Timothy A.; Brown, David; Brown, David; Brownell, James H.; Bruchon, Mélanie; Brueck, Heiner; Brummitt, Amanda J.; Brun, Nicole; Buchholz, Peter; Budagov, Yulian A.; Bulgheroni, Antonio; Bulyak, Eugene; Bungau, Adriana; Bürger, Jochen; Burke, Dan; Burkhart, Craig; Burrows, Philip; Burt, Graeme; Burton, David; Büsser, Karsten; Butler, John; Butterworth, Jonathan; Buzulutskov, Alexei; Cabruja, Enric; Caccia, Massimo; Cai, Yunhai; Calcaterra, Alessandro; Caliier, Stephane; Camporesi, Tiziano; Cao, Jun-Jie; Cao, J.S.; Capatina, Ofelia; Cappellini, Chiara; Carcagno, Ruben; Carena, Marcela; Carloganu, Cristina; Carosi, Roberto; Stephen Carr, F.; Carrion, Francisco; Carter, Harry F.; Carter, John; Carwardine, John; Cassel, Richard; Cassell, Ronald; Cavallari, Giorgio; Cavallo, Emanuela; Cembranos, Jose A.R.; Chakraborty, Dhiman; Chandez, Frederic; Charles, Matthew; Chase, Brian; Chattopadhyay, Subhasis; Chauveau, Jacques; Chefdeville, Maximilien; Chehab, Robert; Chel, Stéphane; Chelkov, Georgy; Chen, Chiping; Chen, He Sheng; Chen, Huai Bi; Chen, Jia Er; Chen, Sen Yu; Chen, Shaomin; Chen, Shenjian; Chen, Xun; Chen, Yuan Bo; Cheng, Jian; Chevallier, M.; Chi, Yun Long; Chickering, William; Cho, Gi-Chol; Cho, Moo-Hyun; Choi, Jin-Hyuk; Choi, Jong Bum; Choi, Seong Youl; Choi, Young-Il; Choudhary, Brajesh; Choudhury, Debajyoti; Rai Choudhury, S.; Christian, David; Christian, Glenn; Christophe, Grojean; Chung, Jin-Hyuk; Church, Mike; Ciborowski, Jacek; Cihangir, Selcuk; Ciovati, Gianluigi; Clarke, Christine; Clarke, Don G.; Clarke, James A.; Clements, Elizabeth; Coca, Cornelia; Coe, Paul; Cogan, John; Colas, Paul; Collard, Caroline; Colledani, Claude; Combaret, Christophe; Comerma, Albert; Compton, Chris; Constance, Ben; Conway, John; Cook, Ed; Cooke, Peter; Cooper, William; Corcoran, Sean; Cornat, Rémi; Corner, Laura; Cortina Gil, Eduardo; Clay Corvin, W.; Cotta Ramusino, Angelo; Cowan, Ray; Crawford, Curtis; Cremaldi, Lucien M; Crittenden, James A.; Cussans, David; Cvach, Jaroslav; da Silva, Wilfrid; Dabiri Khah, Hamid; Dabrowski, Anne; Dabrowski, Wladyslaw; Dadoun, Olivier; Dai, Jian Ping; Dainton, John; Daly, Colin; Danilov, Mikhail; Daniluk, Witold; Daram, Sarojini; Datta, Anindya; Dauncey, Paul; David, Jacques; Davier, Michel; Davies, Ken P.; Dawson, Sally; De Boer, Wim; De Curtis, Stefania; De Groot, Nicolo; de la Taille, Christophe; de Lira, Antonio; De Roeck, Albert; de Sangro, Riccardo; De Santis,Stefano; Deacon, Laurence; Deandrea, Aldo; Dehmelt, Klaus; Delagnes, Eric; Delahaye, Jean-Pierre; Delebecque, Pierre; Delerue, Nicholas; Delferriere, Olivier; Demarteau, Marcel; Deng, Zhi; Denisov, Yu.N.; Densham, Christopher J.; Desch, Klaus; Deshpande, Nilendra; Devanz, Guillaume; Devetak, Erik; Dexter, Amos; Di benedetto, Vito; Diéguez, Angel; Diener, Ralf; Dinh, Nguyen Dinh; Dixit, Madhu; Dixit, Sudhir; Djouadi, Abdelhak; Dolezal, Zdenek; Dollan, Ralph; Dong, Dong; Dong, Hai Yi; Dorfan, Jonathan; Dorokhov, Andrei; Doucas, George; Downing, Robert; Doyle, Eric; Doziere, Guy; Drago, Alessandro; Dragt, Alex; Drake, Gary; Drásal, Zbynek; Dreiner, Herbert; Drell, Persis; Driouichi, Chafik; Drozhdin, Alexandr; Drugakov, Vladimir; Du, Shuxian; Dugan, Gerald; Duginov, Viktor; Dulinski, Wojciech; Dulucq, Frederic; Dutta, Sukanta; Dwivedi, Jishnu; Dychkant, Alexandre; Dzahini, Daniel; Eckerlin, Guenter; Edwards, Helen; Ehrenfeld, Wolfgang; Ehrlichman, Michael; Ehrlichmann, Heiko; Eigen, Gerald; Elagin, Andrey; Elementi, Luciano; Eliasson, Peder; Ellis, John; Ellwood, George; Elsen, Eckhard; Emery, Louis; Enami, Kazuhiro; Endo, Kuninori; Enomoto, Atsushi; Eozénou, Fabien; Erbacher, Robin; Erickson, Roger; Oleg Eyser, K.; Fadeyev, Vitaliy; Fang, Shou Xian; Fant, Karen; Fasso, Alberto; Faucci Giannelli, Michele; Fehlberg, John; Feld, Lutz; Feng, Jonathan L.; Ferguson, John; Fernandez-Garcia, Marcos; Luis Fernandez-Hernando, J.; Fiala, Pavel; Fieguth, Ted; Finch, Alexander; Finocchiaro, Giuseppe; Fischer, Peter; Fisher, Peter; Eugene Fisk, H.; Fitton, Mike D.; Fleck, Ivor; Fleischer, Manfred; Fleury, Julien; Flood, Kevin; Foley, Mike; Ford, Richard; Fortin, Dominique; Foster, Brian; Fourches, Nicolas; Francis, Kurt; Frey, Ariane; Frey, Raymond; Friedsam, Horst; Frisch, Josef; Frishman, Anatoli; Fuerst, Joel; Fujii, Keisuke; Fujimoto, Junpei; Fukuda, Masafumi; Fukuda, Shigeki; Funahashi, Yoshisato; Funk, Warren; Furletova, Julia; Furukawa, Kazuro; Furuta, Fumio; Fusayasu, Takahiro; Fuster, Juan; Gadow, Karsten; Gaede, Frank; Gaglione, Renaud; Gai, Wei; Gajewski, Jan; Galik, Richard; Galkin, Alexei; Galkin, Valery; Gallin-Martel, Laurent; Gannaway, Fred; Gao, Jian She; Gao, Jie; Gao, Yuanning; Garbincius, Peter; Garcia-Tabares, Luis; Garren, Lynn; Garrido, Luís; Garutti, Erika; Garvey, Terry; Garwin, Edward; Gascón, David; Gastal, Martin; Gatto, Corrado; Gatto, Raoul; Gay, Pascal; Ge, Lixin; Ge, Ming Qi; Ge, Rui; Geiser, Achim; Gellrich, Andreas; Genat, Jean-Francois; Geng, Zhe Qiao; Gentile, Simonetta; Gerbick, Scot; Gerig, Rod; Ghosh, Dilip Kumar; Ghosh, Kirtiman; Gibbons, Lawrence; Giganon, Arnaud; Gillespie, Allan; Gillman, Tony; Ginzburg, Ilya; Giomataris, Ioannis; Giunta, Michele; Gladkikh, Peter; Gluza, Janusz; Godbole, Rohini; Godfrey, Stephen; Goldhaber, Gerson; Goldstein, Joel; Gollin, George D.; Gonzalez-Sanchez, Francisco Javier; Goodrick, Maurice; Gornushkin, Yuri; Gostkin, Mikhail; Gottschalk, Erik; Goudket, Philippe; Gough Eschrich, Ivo; Gournaris, Filimon; Graciani, Ricardo; Graf, Norman; Grah, Christian; Grancagnolo, Francesco; Grandjean, Damien; Grannis, Paul; Grassellino, Anna; Graugés, Eugeni; Gray, Stephen; Green, Michael; Greenhalgh, Justin; Greenshaw, Timothy; Grefe, Christian; Gregor, Ingrid-Maria; Grenier, Gerald; Grimes, Mark; Grimm, Terry; Gris, Philippe; Grivaz, Jean-Francois; Groll, Marius; Gronberg, Jeffrey; Grondin, Denis; Groom, Donald; Gross, Eilam; Grunewald, Martin; Grupen, Claus; Grzelak, Grzegorz; Gu, Jun; Gu, Yun-Ting; Guchait, Monoranjan; Guiducci, Susanna; Guler, Ali Murat; Guler, Hayg; Gulmez, Erhan; Gunion, John; Guo, Zhi Yu; Gurtu, Atul; Ha, Huy Bang; Haas, Tobias; Haase, Andy; Haba, Naoyuki; Haber, Howard; Haensel, Stephan; Hagge, Lars; Hagura, Hiroyuki; Hajdu, Csaba; Haller, Gunther; Haller, Johannes; Hallermann, Lea; Halyo, Valerie; Hamaguchi, Koichi; Hammond, Larry; Han, Liang; Han, Tao; Hand, Louis; Handu, Virender K.; Hano, Hitoshi; Hansen, Christian; Hansen, Jørn Dines; Hansen, Jorgen Beck; Hara, Kazufumi; Harder, Kristian; Hartin, Anthony; Hartung, Walter; Hast, Carsten; Hauptman, John; Hauschild, Michael; Hauviller, Claude; Havranek, Miroslav; Hawkes, Chris; Hawkings, Richard; Hayano, Hitoshi; Hazumi, Masashi; He, An; He, Hong Jian; Hearty, Christopher; Heath, Helen; Hebbeker, Thomas; Hedberg, Vincent; Hedin, David; Heifets, Samuel; Heinemeyer, Sven; Heini, Sebastien; Helebrant, Christian; Helms, Richard; Heltsley, Brian; Henrot-Versille, Sophie; Henschel, Hans; Hensel, Carsten; Hermel, Richard; Herms, Atilà; Herten, Gregor; Hesselbach, Stefan; Heuer, Rolf-Dieter; Heusch, Clemens A.; Hewett, Joanne; Higashi, Norio; Higashi, Takatoshi; Higashi, Yasuo; Higo, Toshiyasu; Hildreth, Michael D.; Hiller, Karlheinz; Hillert, Sonja; Hillier, Stephen James; Himel, Thomas; Himmi, Abdelkader; Hinchliffe, Ian; Hioki, Zenro; Hirano, Koichiro; Hirose, Tachishige; Hisamatsu, Hiromi; Hisano, Junji; Hlaing, Chit Thu; Hock, Kai Meng; Hoeferkamp, Martin; Hohlfeld, Mark; Honda, Yousuke; Hong, Juho; Hong, Tae Min; Honma, Hiroyuki; Horii, Yasuyuki; Horvath, Dezso; Hosoyama, Kenji; Hostachy, Jean-Yves; Hou, Mi; Hou, Wei-Shu; Howell, David; Hronek, Maxine; Hsiung, Yee B.; Hu, Bo; Hu, Tao; Huang, Jung-Yun; Huang, Tong Ming; Huang, Wen Hui; Huedem, Emil; Huggard, Peter; Hugonie, Cyril; Hu-Guo, Christine; Huitu, Katri; Hwang, Youngseok; Idzik, Marek; Ignatenko, Alexandr; Ignatov, Fedor; Ikeda, Hirokazu; Ikematsu, Katsumasa; Ilicheva, Tatiana; Imbault, Didier; Imhof, Andreas; Incagli, Marco; Ingbir, Ronen; Inoue, Hitoshi; Inoue, Youichi; Introzzi, Gianluca; Ioakeimidi, Katerina; Ishihara, Satoshi; Ishikawa, Akimasa; Ishikawa, Tadashi; Issakov, Vladimir; Ito, Kazutoshi; Ivanov, V.V.; Ivanov, Valentin; Ivanyushenkov, Yury; Iwasaki, Masako; Iwashita, Yoshihisa; Jackson, David; Jackson, Frank; Jacobsen, Bob; Jaganathan, Ramaswamy; Jamison, Steven; Janssen, Matthias Enno; Jaramillo-Echeverria, Richard; Jauffret, Clement; Jawale, Suresh B.; Jeans, Daniel; Jedziniak, Ron; Jeffery, Ben; Jehanno, Didier; Jenner, Leo J.; Jensen, Chris; Jensen, David R.; Jiang, Hairong; Jiang, Xiao Ming; Jimbo, Masato; Jin, Shan; Keith Jobe, R.; Johnson, Anthony; Johnson, Erik; Johnson, Matt; Johnston, Michael; Joireman, Paul; Jokic, Stevan; Jones, James; Jones, Roger M.; Jongewaard, Erik; Jönsson, Leif; Joshi, Gopal; Joshi, Satish C.; Jung, Jin-Young; Junk, Thomas; Juste, Aurelio; Kado, Marumi; Kadyk, John; Käfer, Daniela; Kako, Eiji; Kalavase, Puneeth; Kalinin, Alexander; Kalinowski, Jan; Kamitani, Takuya; Kamiya, Yoshio; Kamiya, Yukihide; Kamoshita, Jun-ichi; Kananov, Sergey; Kanaya, Kazuyuki; Kanazawa, Ken-ichi; Kanemura, Shinya; Kang, Heung-Sik; Kang, Wen; Kanjial, D.; Kapusta, Frédéric; Karataev, Pavel; Karchin, Paul E.; Karlen, Dean; Karyotakis, Yannis; Kashikhin, Vladimir; Kashiwagi, Shigeru; Kasley, Paul; Katagiri, Hiroaki; Kato, Takashi; Kato, Yukihiro; Katzy, Judith; Kaukher, Alexander; Kaur, Manjit; Kawagoe, Kiyotomo; Kawamura, Hiroyuki; Kazakov, Sergei; Kekelidze, V.D.; Keller, Lewis; Kelley, Michael; Kelly, Marc; Kelly, Michael; Kennedy, Kurt; Kephart, Robert; Keung, Justin; Khainovski, Oleg; Khan, Sameen Ahmed; Khare, Prashant; Khovansky, Nikolai; Kiesling, Christian; Kikuchi, Mitsuo; Kilian, Wolfgang; Killenberg, Martin; Kim, Donghee; Kim, Eun San; Kim, Eun-Joo; Kim, Guinyun; Kim, Hongjoo; Kim, Hyoungsuk; Kim, Hyun-Chui; Kim, Jonghoon; Kim, Kwang-Je; Kim, Kyung Sook; Kim, Peter; Kim, Seunghwan; Kim, Shin-Hong; Kim, Sun Kee; Kim, Tae Jeong; Kim, Youngim; Kim, Young-Kee; Kimmitt, Maurice; Kirby, Robert; Kircher, François; Kisielewska, Danuta; Kittel, Olaf; Klanner, Robert; Klebaner, Arkadiy L.; Kleinwort, Claus; Klimkovich, Tatsiana; Klinkby, Esben; Kluth, Stefan; Knecht, Marc; Kneisel, Peter; Ko, In Soo; Ko, Kwok; Kobayashi, Makoto; Kobayashi, Nobuko; Kobel, Michael; Koch, Manuel; Kodys, Peter; Koetz, Uli; Kohrs, Robert; Kojima, Yuuji; Kolanoski, Hermann; Kolodziej, Karol; Kolomensky, Yury G.; Komamiya, Sachio; Kong, Xiang Cheng; Konigsberg, Jacobo; Korbel, Volker; Koscielniak, Shane; Kostromin, Sergey; Kowalewski, Robert; Kraml, Sabine; Krammer, Manfred; Krasnykh, Anatoly; Krautscheid, Thorsten; Krawczyk, Maria; James Krebs, H.; Krempetz, Kurt; Kribs, Graham; Krishnagopal, Srinivas; Kriske, Richard; Kronfeld, Andreas; Kroseberg, Jürgen; Kruchonak, Uladzimir; Kruecker, Dirk; Krüger, Hans; Krumpa, Nicholas A.; Krumshtein, Zinovii; Kuang, Yu Ping; Kubo, Kiyoshi; Kuchler, Vic; Kudoh, Noboru; Kulis, Szymon; Kumada, Masayuki; Kumar, Abhay; Kume, Tatsuya; Kundu, Anirban; Kurevlev, German; Kurihara, Yoshimasa; Kuriki, Masao; Kuroda, Shigeru; Kuroiwa, Hirotoshi; Kurokawa, Shin-ichi; Kusano, Tomonori; Kush, Pradeep K.; Kutschke, Robert; Kuznetsova, Ekaterina; Kvasnicka, Peter; Kwon, Youngjoon; Labarga, Luis; Lacasta, Carlos; Lackey, Sharon; Lackowski, Thomas W.; Lafaye, Remi; Lafferty, George; Lagorio, Eric; Laktineh, Imad; Lal, Shankar; Laloum, Maurice; Lam, Briant; Lancaster, Mark; Lander, Richard; Lange, Wolfgang; Langenfeld, Ulrich; Langeveld, Willem; Larbalestier, David; Larsen, Ray; Lastovicka, Tomas; Lastovicka-Medin, Gordana; Latina, Andrea; Latour, Emmanuel; Laurent, Lisa; Le, Ba Nam; Le, Duc Ninh; Le Diberder, Francois; Dû, Patrick Le; Lebbolo, Hervé; Lebrun, Paul; Lecoq, Jacques; Lee, Sung-Won; Lehner, Frank; Leibfritz, Jerry; Lenkszus, Frank; Lesiak, Tadeusz; Levy, Aharon; Lewandowski, Jim; Leyh, Greg; Li, Cheng; Li, Chong Sheng; Li, Chun Hua; Li, Da Zhang; Li, Gang; Li, Jin; Li, Shao Peng; Li, Wei Ming; Li, Weiguo; Li, Xiao Ping; Li, Xue-Qian; Li, Yuanjing; Li, Yulan; Li, Zenghai; Li, Zhong Quan; Liang, Jian Tao; Liao, Yi; Lilje, Lutz; Guilherme Lima, J.; Lintern, Andrew J.; Lipton, Ronald; List, Benno; List, Jenny; Liu, Chun; Liu, Jian Fei; Liu, Ke Xin; Liu, Li Qiang; Liu, Shao Zhen; Liu, Sheng Guang; Liu, Shubin; Liu, Wanming; Liu, Wei Bin; Liu, Ya Ping; Liu, Yu Dong; Lockyer, Nigel; Logan, Heather E.; Logatchev, Pavel V.; Lohmann, Wolfgang; Lohse, Thomas; Lola, Smaragda; Lopez-Virto, Amparo; Loveridge, Peter; Lozano, Manuel; Lu, Cai-Dian; Lu, Changguo; Lu, Gong-Lu; Lu, Wen Hui; Lubatti, Henry; Lucotte, Arnaud; Lundberg, Björn; Lundin, Tracy; Luo, Mingxing; Luong, Michel; Luth, Vera; Lutz, Benjamin; Lutz, Pierre; Lux, Thorsten; Luzniak, Pawel; Lyapin, Alexey; Lykken, Joseph; Lynch, Clare; Ma, Li; Ma, Lili; Ma, Qiang; Ma, Wen-Gan; Macfarlane, David; Maciel, Arthur; MacLeod, Allan; MacNair, David; Mader, Wolfgang; Magill, Stephen; Magnan, Anne-Marie; Maiheu, Bino; Maity, Manas; Majchrzak, Millicent; Majumder, Gobinda; Makarov, Roman; Makowski, Dariusz; Malaescu, Bogdan; Mallik, C.; Mallik, Usha; Malton, Stephen; Malyshev, Oleg B.; Malysheva, Larisa I.; Mammosser, John; Mamta; Mamuzic, Judita; Manen, Samuel; Manghisoni, Massimo; Manly, Steven; Marcellini, Fabio; Marcisovsky, Michal; Markiewicz, Thomas W.; Marks, Steve; Marone, Andrew; Marti, Felix; Martin, Jean-Pierre; Martin, Victoria; Martin-Chassard, Gisèle; Martinez, Manel; Martinez-Rivero, Celso; Martsch, Dennis; Martyn, Hans-Ulrich; Maruyama, Takashi; Masuzawa, Mika; Mathez, Hervé; Matsuda, Takeshi; Matsumoto, Hiroshi; Matsumoto, Shuji; Matsumoto, Toshihiro; Matsunaga, Hiroyuki; Mättig, Peter; Mattison, Thomas; Mavromanolakis, Georgios; Mawatari, Kentarou; Mazzacane, Anna; McBride, Patricia; McCormick, Douglas; McCormick, Jeremy; McDonald, Kirk T.; McGee, Mike; McIntosh, Peter; McKee, Bobby; McPherson, Robert A.; Meidlinger, Mandi; Meier, Karlheinz; Mele, Barbara; Meller, Bob; Melzer-Pellmann, Isabell-Alissandra; Mendez, Hector; Mercer, Adam; Merkin, Mikhail; Meshkov, I.N.; Messner, Robert; Metcalfe, Jessica; Meyer, Chris; Meyer, Hendrik; Meyer, Joachim; Meyer, Niels; Meyners, Norbert; Michelato, Paolo; Michizono, Shinichiro; Mihalcea, Daniel; Mihara, Satoshi; Mihara, Takanori; Mikami, Yoshinari; Mikhailichenko, Alexander A.; Milardi, Catia; Miller, David J.; Miller, Owen; Miller, Roger J.; Milstene, Caroline; Mimashi, Toshihiro; Minashvili, Irakli; Miquel, Ramon; Mishra, Shekhar; Mitaroff, Winfried; Mitchell, Chad; Miura, Takako; Miyata, Hitoshi; Mjörnmark, Ulf; Mnich, Joachim; Moenig, Klaus; Moffeit, Kenneth; Mokhov, Nikolai; Molloy, Stephen; Monaco, Laura; Monasterio, Paul R.; Montanari, Alessandro; Moon, Sung Ik; Moortgat-Pick, Gudrid A.; Mora de Freitas, Paulo; Morel, Federic; Moretti, Stefano; Morgunov, Vasily; Mori, Toshinori; Morin, Laurent; Morisseau, François; Morita, Yoshiyuki; Morita, Youhei; Morita, Yuichi; Morozov, Nikolai; Morozumi, Yuichi; Morse, William; Moser, Hans-Guenther; Moultaka, Gilbert; Mtingwa, Sekazi; Mudrinic, Mihajlo; Mueller, Alex; Mueller, Wolfgang; Muennich, Astrid; Muhlleitner, Milada Margarete; Mukherjee, Bhaskar; Mukhopadhyaya, Biswarup; Müller, Thomas; Munro, Morrison; Murayama, Hitoshi; Muto, Toshiya; Myneni, Ganapati Rao; Nabhiraj, P.Y.; Nagaitsev, Sergei; Nagamine, Tadashi; Nagano, Ai; Naito, Takashi; Nakai, Hirotaka; Nakajima, Hiromitsu; Nakamura, Isamu; Nakamura, Tomoya; Nakanishi, Tsutomu; Nakao, Katsumi; Nakao, Noriaki; Nakayoshi, Kazuo; Nam, Sang; Namito, Yoshihito; Namkung, Won; Nantista, Chris; Napoly, Olivier; Narain, Meenakshi; Naroska, Beate; Nauenberg, Uriel; Nayyar, Ruchika; Neal, Homer; Nelson, Charles; Nelson, Janice; Nelson, Timothy; Nemecek, Stanislav; Neubauer, Michael; Neuffer, David; Newman, Myriam Q.; Nezhevenko, Oleg; Ng, Cho-Kuen; Nguyen, Anh Ky; Nguyen, Minh; Van Nguyen Thi,Hong; Niebuhr, Carsten; Niehoff, Jim; Niezurawski, Piotr; Nishitani, Tomohiro; Nitoh, Osamu; Noguchi, Shuichi; Nomerotski, Andrei; Noonan, John; Norbeck, Edward; Nosochkov, Yuri; Notz, Dieter; Nowak, Grazyna; Nowak, Hannelies; Noy, Matthew; Nozaki, Mitsuaki; Nyffeler, Andreas; Nygren, David; Oddone, Piermaria; O'Dell, Joseph; Oh, Jong-Seok; Oh, Sun Kun; Ohkuma, Kazumasa; Ohlerich, Martin; Ohmi, Kazuhito; Ohnishi, Yukiyoshi; Ohsawa, Satoshi; Ohuchi, Norihito; Oide, Katsunobu; Okada, Nobuchika; Okada, Yasuhiro; Okamura, Takahiro; Okugi, Toshiyuki; Okumi, Shoji; Okumura, Ken-ichi; Olchevski, Alexander; Oliver, William; Olivier, Bob; Olsen, James; Olsen, Jeff; Olsen, Stephen; Olshevsky, A.G.; Olsson, Jan; Omori, Tsunehiko; Onel, Yasar; Onengut, Gulsen; Ono, Hiroaki; Onoprienko, Dmitry; Oreglia, Mark; Oren, Will; Orimoto, Toyoko J.; Oriunno, Marco; Orlandea, Marius Ciprian; Oroku, Masahiro; Orr, Lynne H.; Orr, Robert S.; Oshea, Val; Oskarsson, Anders; Osland, Per; Ossetski, Dmitri; Österman, Lennart; Ostiguy, Francois; Otono, Hidetoshi; Ottewell, Brian; Ouyang, Qun; Padamsee, Hasan; Padilla, Cristobal; Pagani, Carlo; Palmer, Mark A.; Pam, Wei Min; Pande, Manjiri; Pande, Rajni; Pandit, V.S.; Pandita, P.N.; Pandurovic, Mila; Pankov, Alexander; Panzeri, Nicola; Papandreou, Zisis; Paparella, Rocco; Para, Adam; Park, Hwanbae; Parker, Brett; Parkes, Chris; Parma, Vittorio; Parsa, Zohreh; Parsons, Justin; Partridge, Richard; Pasquinelli, Ralph; Pásztor, Gabriella; Paterson, Ewan; Patrick, Jim; Patteri, Piero; Ritchie Patterson, J.; Pauletta, Giovanni; Paver, Nello; Pavlicek, Vince; Pawlik, Bogdan; Payet, Jacques; Pchalek, Norbert; Pedersen, John; Pei, Guo Xi; Pei, Shi Lun; Pelka, Jerzy; Pellegrini, Giulio; Pellett, David; Peng, G.X.; Penn, Gregory; Penzo, Aldo; Perry, Colin; Peskin, Michael; Peters, Franz; Petersen, Troels Christian; Peterson, Daniel; Peterson, Thomas; Petterson, Maureen; Pfeffer, Howard; Pfund, Phil; Phelps, Alan; Van Phi, Quang; Phillips, Jonathan; Phinney, Nan; Piccolo, Marcello; Piemontese, Livio; Pierini, Paolo; Thomas Piggott, W.; Pike, Gary; Pillet, Nicolas; Jayawardena, Talini Pinto; Piot, Phillippe; Pitts, Kevin; Pivi, Mauro; Plate, Dave; Pleier, Marc-Andre; Poblaguev, Andrei; Poehler, Michael; Poelker, Matthew; Poffenberger, Paul; Pogorelsky, Igor; Poirier, Freddy; Poling, Ronald; Poole, Mike; Popescu, Sorina; Popielarski, John; Pöschl, Roman; Postranecky, Martin; Potukochi, Prakash N.; Prast, Julie; Prat, Serge; Preger, Miro; Prepost, Richard; Price, Michael; Proch, Dieter; Puntambekar, Avinash; Qin, Qing; Qu, Hua Min; Quadt, Arnulf; Quesnel, Jean-Pierre; Radeka, Veljko; Rahmat, Rahmat; Rai, Santosh Kumar; Raimondi, Pantaleo; Ramberg, Erik; Ranjan, Kirti; Rao, Sista V.L.S.; Raspereza, Alexei; Ratti, Alessandro; Ratti, Lodovico; Raubenheimer, Tor; Raux, Ludovic; Ravindran, V.; Raychaudhuri, Sreerup; Re, Valerio; Rease, Bill; Reece, Charles E.; Regler, Meinhard; Rehlich, Kay; Reichel, Ina; Reichold, Armin; Reid, John; Reid, Ron; Reidy, James; Reinhard, Marcel; Renz, Uwe; Repond, Jose; Resta-Lopez, Javier; Reuen, Lars; Ribnik, Jacob; Rice, Tyler; Richard, François; Riemann, Sabine; Riemann, Tord; Riles, Keith; Riley, Daniel; Rimbault, Cécile; Rindani, Saurabh; Rinolfi, Louis; Risigo, Fabio; Riu, Imma; Rizhikov, Dmitri; Rizzo, Thomas; Rochford, James H.; Rodriguez, Ponciano; Roeben, Martin; Rolandi, Gigi; Roodman, Aaron; Rosenberg, Eli; Roser, Robert; Ross, Marc; Rossel, François; Rossmanith, Robert; Roth, Stefan; Rougé, André; Rowe, Allan; Roy, Amit; Roy, Sendhunil B.; Roy, Sourov; Royer, Laurent; Royole-Degieux, Perrine; Royon, Christophe; Ruan, Manqi; Rubin, David; Ruehl, Ingo; Jimeno, Alberto Ruiz; Ruland, Robert; Rusnak, Brian; Ryu, Sun-Young; Sabbi, Gian Luca; Sadeh, Iftach; Sadygov, Ziraddin Y; Saeki, Takayuki; Sagan, David; Sahni, Vinod C.; Saini, Arun; Saito, Kenji; Saito, Kiwamu; Sajot, Gerard; Sakanaka, Shogo; Sakaue, Kazuyuki; Salata, Zen; Salih, Sabah; Salvatore, Fabrizio; Samson, Joergen; Sanami, Toshiya; Levi Sanchez, Allister; Sands, William; Santic, John; Sanuki, Tomoyuki; Sapronov, Andrey; Sarkar, Utpal; Sasao, Noboru; Satoh, Kotaro; Sauli, Fabio; Saunders, Claude; Saveliev, Valeri; Savoy-Navarro, Aurore; Sawyer, Lee; Saxton, Laura; Schäfer, Oliver; Schälicke, Andreas; Schade, Peter; Schaetzel, Sebastien; Scheitrum, Glenn; Schibler, Emilie; Schindler, Rafe; Schlösser, Markus; Schlueter, Ross D.; Schmid, Peter; Schmidt, Ringo Sebastian; Schneekloth, Uwe; Schreiber, Heinz Juergen; Schreiber, Siegfried; Schroeder, Henning; Peter Schüler, K.; Schulte, Daniel; Schultz-Coulon, Hans-Christian; Schumacher, Markus; Schumann, Steffen; Schumm, Bruce A.; Schwienhorst, Reinhard; Schwierz, Rainer; Scott, Duncan J.; Scuri, Fabrizio; Sefkow, Felix; Sefri, Rachid; Seguin-Moreau, Nathalie; Seidel, Sally; Seidman, David; Sekmen, Sezen; Seletskiy, Sergei; Senaha, Eibun; Senanayake, Rohan; Sendai, Hiroshi; Sertore, Daniele; Seryi, Andrei; Settles, Ronald; Sever, Ramazan; Shales, Nicholas; Shao, Ming; Shelkov, G.A.; Shepard, Ken; Shepherd-Themistocleous, Claire; Sheppard, John C.; Shi, Cai Tu; Shidara, Tetsuo; Shim, Yeo-Jeong; Shimizu, Hirotaka; Shimizu, Yasuhiro; Shimizu, Yuuki; Shimogawa, Tetsushi; Shin, Seunghwan; Shioden, Masaomi; Shipsey, Ian; Shirkov, Grigori; Shishido, Toshio; Shivpuri, Ram K.; Shrivastava, Purushottam; Shulga, Sergey; Shumeiko, Nikolai; Shuvalov, Sergey; Si, Zongguo; Siddiqui, Azher Majid; Siegrist, James; Simon, Claire; Simrock, Stefan; Sinev, Nikolai; Singh, Bhartendu K.; Singh, Jasbir; Singh, Pitamber; Singh, R.K.; Singh, S.K.; Singini, Monito; Sinha, Anil K.; Sinha, Nita; Sinha, Rahul; Sinram, Klaus; Sissakian, A.N.; Skachkov, N.B.; Skrinsky, Alexander; Slater, Mark; Slominski, Wojciech; Smiljanic, Ivan; Smith, A J Stewart; Smith, Alex; Smith, Brian J.; Smith, Jeff; Smith, Jonathan; Smith, Steve; Smith, Susan; Smith, Tonee; Neville Snodgrass, W.; Sobloher, Blanka; Sohn, Young-Uk; Solidum, Ruelson; Solyak, Nikolai; Son, Dongchul; Sonmez, Nasuf; Sopczak, Andre; Soskov, V.; Spencer, Cherrill M.; Spentzouris, Panagiotis; Speziali, Valeria; Spira, Michael; Sprehn, Daryl; Sridhar, K.; Srivastava, Asutosh; St. Lorant, Steve; Stahl, Achim; Stanek, Richard P.; Stanitzki, Marcel; Stanley, Jacob; Stefanov, Konstantin; Stein, Werner; Steiner, Herbert; Stenlund, Evert; Stern, Amir; Sternberg, Matt; Stockinger, Dominik; Stockton, Mark; Stoeck, Holger; Strachan, John; Strakhovenko, V.; Strauss, Michael; Striganov, Sergei I.; Strologas, John; Strom, David; Strube, Jan; Stupakov, Gennady; Su, Dong; Sudo, Yuji; Suehara, Taikan; Suehiro, Toru; Suetsugu, Yusuke; Sugahara, Ryuhei; Sugimoto, Yasuhiro; Sugiyama, Akira; Suh, Jun Suhk; Sukovic, Goran; Sun, Hong; Sun, Stephen; Sun, Werner; Sun, Yi; Sun, Yipeng; Suszycki, Leszek; Sutcliffe, Peter; Suthar, Rameshwar L.; Suwada, Tsuyoshi; Suzuki, Atsuto; Suzuki, Chihiro; Suzuki, Shiro; Suzuki, Takashi; Swent, Richard; Swientek, Krzysztof; Swinson, Christina; Syresin, Evgeny; Szleper, Michal; Tadday, Alexander; Takahashi, Rika; Takahashi, Tohru; Takano, Mikio; Takasaki, Fumihiko; Takeda, Seishi; Takenaka, Tateru; Takeshita, Tohru; Takubo, Yosuke; Tanaka, Masami; Tang, Chuan Xiang; Taniguchi, Takashi; Tantawi, Sami; Tapprogge, Stefan; Tartaglia, Michael A.; Tassielli, Giovanni Francesco; Tauchi, Toshiaki; Tavian, Laurent; Tawara, Hiroko; Taylor, Geoffrey; Telnov, Alexandre V.; Telnov, Valery; Tenenbaum, Peter; Teodorescu, Eliza; Terashima, Akio; Terracciano, Giuseppina; Terunuma, Nobuhiro; Teubner, Thomas; Teuscher, Richard; Theilacker, Jay; Thomson, Mark; Tice, Jeff; Tigner, Maury; Timmermans, Jan; Titov, Maxim; Toge, Nobukazu; Tokareva, N.A.; Tollefson, Kirsten; Tomasek, Lukas; Tomovic, Savo; Tompkins, John; Tonutti, Manfred; Topkar, Anita; Toprek, Dragan; Toral, Fernando; Torrence, Eric; Traversi, Gianluca; Trimpl, Marcel; Mani Tripathi, S.; Trischuk, William; Trodden, Mark; Trubnikov, G.V.; Tschirhart, Robert; Tskhadadze, Edisher; Tsuchiya, Kiyosumi; Tsukamoto, Toshifumi; Tsunemi, Akira; Tucker, Robin; Turchetta, Renato; Tyndel, Mike; Uekusa, Nobuhiro; Ueno, Kenji; Umemori, Kensei; Ummenhofer, Martin; Underwood, David; Uozumi, Satoru; Urakawa, Junji; Urban, Jeremy; Uriot, Didier; Urner, David; Ushakov, Andrei; Usher, Tracy; Uzunyan, Sergey; Vachon, Brigitte; Valerio, Linda; Valin, Isabelle; Valishev, Alex; Vamra, Raghava; Van der Graaf, Harry; Van Kooten, Rick; Van Zandbergen, Gary; Vanel, Jean-Charles; Variola, Alessandro; Varner, Gary; Velasco, Mayda; Velte, Ulrich; Velthuis, Jaap; Vempati, Sundir K.; Venturini, Marco; Vescovi, Christophe; Videau, Henri; Vila, Ivan; Vincent, Pascal; Virey, Jean-Marc; Visentin, Bernard; Viti, Michele; Vo, Thanh Cuong; Vogel, Adrian; Vogt, Harald; von Toerne, Eckhard; Vorozhtsov, S.B.; Vos, Marcel; Votava, Margaret; Vrba, Vaclav; Wackeroth, Doreen; Wagner, Albrecht; Wagner, Carlos E.M.; Wagner, Stephen; Wake, Masayoshi; Walczak, Roman; Walker, Nicholas J.; Walkowiak, Wolfgang; Wallon, Samuel; Walsh, Roberval; Walston, Sean; Waltenberger, Wolfgang; Walz, Dieter; Wang, Chao En; Wang, Chun Hong; Wang, Dou; Wang, Faya; Wang, Guang Wei; Wang, Haitao; Wang, Jiang; Wang, Jiu Qing; Wang, Juwen; Wang, Lanfa; Wang, Lei; Wang, Min-Zu; Wang, Qing; Wang, Shu Hong; Wang, Xiaolian; Wang, Xue-Lei; Wang, Yi Fang; Wang, Zheng; Wanzenberg, Rainer; Ward, Bennie; Ward, David; Warmbein, Barbara; Warner, David W.; Warren, Matthew; Washio, Masakazu; Watanabe, Isamu; Watanabe, Ken; Watanabe, Takashi; Watanabe, Yuichi; Watson, Nigel; Wattimena, Nanda; Wayne, Mitchell; Weber, Marc; Weerts, Harry; Weiglein, Georg; Weiland, Thomas; Weinzierl, Stefan; Weise, Hans; Weisend, John; Wendt, Manfred; Wendt, Oliver; Wenzel, Hans; Wenzel, William A.; Wermes, Norbert; Werthenbach, Ulrich; Wesseln, Steve; Wester, William; White, Andy; White, Glen R.; Wichmann, Katarzyna; Wienemann, Peter; Wierba, Wojciech; Wilksen, Tim; Willis, William; Wilson, Graham W.; Wilson, John A.; Wilson, Robert; Wing, Matthew; Winter, Marc; Wirth, Brian D.; Wolbers, Stephen A.; Wolff, Dan; Wolski, Andrzej; Woodley, Mark D.; Woods, Michael; Woodward, Michael L.; Woolliscroft, Timothy; Worm, Steven; Wormser, Guy; Wright, Dennis; Wright, Douglas; Wu, Andy; Wu, Tao; Wu, Yue Liang; Xella, Stefania; Xia, Guoxing; Xia, Lei; Xiao, Aimin; Xiao, Liling; Xie, Jia Lin; Xing, Zhi-Zhong; Xiong, Lian You; Xu, Gang; Xu, Qing Jing; Yajnik, Urjit A.; Yakimenko, Vitaly; Yamada, Ryuji; Yamaguchi, Hiroshi; Yamamoto, Akira; Yamamoto, Hitoshi; Yamamoto, Masahiro; Yamamoto, Naoto; Yamamoto, Richard; Yamamoto, Yasuchika; Yamanaka, Takashi; Yamaoka, Hiroshi; Yamashita, Satoru; Yamazaki, Hideki; Yan, Wenbiao; Yang, Hai-Jun; Yang, Jin Min; Yang, Jongmann; Yang, Zhenwei; Yano, Yoshiharu; Yazgan, Efe; Yeh, G.P.; Yilmaz, Hakan; Yock, Philip; Yoda, Hakutaro; Yoh, John; Yokoya, Kaoru; Yokoyama, Hirokazu; York, Richard C.; Yoshida, Mitsuhiro; Yoshida, Takuo; Yoshioka, Tamaki; Young, Andrew; Yu, Cheng Hui; Yu, Jaehoon; Yu, Xian Ming; Yuan, Changzheng; Yue, Chong-Xing; Yue, Jun Hui; Zacek, Josef; Zagorodnov, Igor; Zalesak, Jaroslav; Zalikhanov, Boris; Zarnecki, Aleksander Filip; Zawiejski, Leszek; Zeitnitz, Christian; Zeller, Michael; Zerwas, Dirk; Zerwas, Peter; Zeyrek, Mehmet; Zhai, Ji Yuan; Zhang, Bao Cheng; Zhang, Bin; Zhang, Chuang; Zhang, He; Zhang, Jiawen; Zhang, Jing; Zhang, Jing Ru; Zhang, Jinlong; Zhang, Liang; Zhang, X.; Zhang, Yuan; Zhang, Zhige; Zhang, Zhiqing; Zhang, Ziping; Zhao, Haiwen; Zhao, Ji Jiu; Zhao, Jing Xia; Zhao, Ming Hua; Zhao, Sheng Chu; Zhao, Tianchi; Zhao, Tong Xian; Zhao, Zhen Tang; Zhao, Zhengguo; Zhou, De Min; Zhou, Feng; Zhou, Shun; Zhu, Shou Hua; Zhu, Xiong Wei; Zhukov, Valery; Zimmermann, Frank; Ziolkowski, Michael; Zisman, Michael S.; Zomer, Fabian; Zong, Zhang Guo; Zorba, Osman; Zutshi, Vishnu

    2007-01-01

    This report, Volume IV of the International Linear Collider Reference Design Report, describes the detectors which will record and measure the charged and neutral particles produced in the ILC's high energy e+e- collisions. The physics of the ILC, and the environment of the machine-detector interface, pose new challenges for detector design. Several conceptual designs for the detector promise the needed performance, and ongoing detector R&D is addressing the outstanding technological issues. Two such detectors, operating in push-pull mode, perfectly instrument the ILC interaction region, and access the full potential of ILC physics.

  9. He-4 fast neutron detectors in nuclear security applications

    International Nuclear Information System (INIS)

    Murer, D. E.

    2014-01-01

    This work presents studies of "4He fast neutron detectors for nuclear security applications. Such devices are high pressure gas scintillation detectors, sensitive to neutrons in the energy range of fission sources. First, an introduction to the scope of the intended application is given. This is followed by a description of all components relevant to the operation of the detector. The next chapter presents studies of various characteristics of the neutron detector, among them properties of its scintillation response, differences between neutron and gamma interactions and effects of the light collection process. The results of the detector characterization are used to develop neutron gamma discrimination methods. These methods are put to the test using measurements with a high gamma flux, and the results are compared to performance requirements of Radiation Portal Monitors. Background neutron measurements are presented next. Measured neutron rates are compared to values published in scientific literature. The fluctuation of the background count rate was studied, and the contribution of muons evaluated. Two applications of the detectors in the field of nuclear security are discussed in the last two chapters. The first one is a novel method to measure the plutonium mass in a container filled with Mixed Oxide Fuel. The last chapter presents the development of a Radiation Portal Monitor which, in addition to neutron and gamma counting, exploits time correlation to detect threats such as plutonium and "6"0Co. (author)

  10. He-4 fast neutron detectors in nuclear security applications

    Energy Technology Data Exchange (ETDEWEB)

    Murer, D. E.

    2014-07-01

    This work presents studies of {sup 4}He fast neutron detectors for nuclear security applications. Such devices are high pressure gas scintillation detectors, sensitive to neutrons in the energy range of fission sources. First, an introduction to the scope of the intended application is given. This is followed by a description of all components relevant to the operation of the detector. The next chapter presents studies of various characteristics of the neutron detector, among them properties of its scintillation response, differences between neutron and gamma interactions and effects of the light collection process. The results of the detector characterization are used to develop neutron gamma discrimination methods. These methods are put to the test using measurements with a high gamma flux, and the results are compared to performance requirements of Radiation Portal Monitors. Background neutron measurements are presented next. Measured neutron rates are compared to values published in scientific literature. The fluctuation of the background count rate was studied, and the contribution of muons evaluated. Two applications of the detectors in the field of nuclear security are discussed in the last two chapters. The first one is a novel method to measure the plutonium mass in a container filled with Mixed Oxide Fuel. The last chapter presents the development of a Radiation Portal Monitor which, in addition to neutron and gamma counting, exploits time correlation to detect threats such as plutonium and {sup 60}Co. (author)

  11. 29 CFR 801.4 - Prohibitions on lie detector use.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 3 2010-07-01 2010-07-01 false Prohibitions on lie detector use. 801.4 Section 801.4 Labor Regulations Relating to Labor (Continued) WAGE AND HOUR DIVISION, DEPARTMENT OF LABOR OTHER LAWS APPLICATION... complaint, for testifying in any proceeding, or for exercising any rights afforded by the Act. (b) An...

  12. X-ray inspection of composite materials for aircraft structures using detectors of Medipix type

    International Nuclear Information System (INIS)

    Jandejsek, I; Jakubek, J; Jakubek, M; Krejci, F; Soukup, P; Turecek, D; Vavrik, D; Zemlicka, J; Prucha, P

    2014-01-01

    This work presents an overview of promising X-ray imaging techniques employed for non-destructive defectoscopy inspections of composite materials intended for the Aircraft industry. The major emphasis is placed on non-tomographic imaging techniques which do not require demanding spatial and time measurement conditions. Imaging methods for defects visualisation, delamination detection and porosity measurement of various composite materials such as carbon fibre reinforced polymers and honeycomb sendwiches are proposed. We make use of the new large area WidePix X-ray imaging camera assembled from up to 100 edgeless Medipix type detectors which is highly suitable for this type of measurements

  13. Modeling an array of encapsulated germanium detectors

    International Nuclear Information System (INIS)

    Kshetri, R

    2012-01-01

    A probability model has been presented for understanding the operation of an array of encapsulated germanium detectors generally known as composite detector. The addback mode of operation of a composite detector has been described considering the absorption and scattering of γ-rays. Considering up to triple detector hit events, we have obtained expressions for peak-to-total and peak-to-background ratios of the cluster detector, which consists of seven hexagonal closely packed encapsulated HPGe detectors. Results have been obtained for the miniball detectors comprising of three and four seven hexagonal closely packed encapsulated HPGe detectors. The formalism has been extended to the SPI spectrometer which is a telescope of the INTEGRAL satellite and consists of nineteen hexagonal closely packed encapsulated HPGe detectors. This spectrometer comprises of twelve detector modules surrounding the cluster detector. For comparison, we have considered a spectrometer comprising of nine detector modules surrounding the three detector configuration of miniball detector. In the present formalism, the operation of these sophisticated detectors could be described in terms of six probability amplitudes only. Using experimental data on relative efficiency and fold distribution of cluster detector as input, the fold distribution and the peak-to-total, peak-to-background ratios have been calculated for the SPI spectrometer and other composite detectors at 1332 keV. Remarkable agreement between experimental data and results from the present formalism has been observed for the SPI spectrometer.

  14. An XML description of detector geometries for GEANT4

    International Nuclear Information System (INIS)

    Figgins, J.; Walker, B.; Comfort, J.R.

    2006-01-01

    A code has been developed that enables the geometry of detectors to be specified easily and flexibly in the XML language, for use in the Monte Carlo program GEANT4. The user can provide clear documentation of the geometry without being proficient in the C++ language of GEANT4. The features and some applications are discussed

  15. Spin-phonon and lattice contributions to the ground-state splitting of Gd3+ and Eu2+ in scheelite crystals

    Science.gov (United States)

    Gorlov, A. D.

    2015-07-01

    The EPR spectra of Gd3+ in CaWO4 single crystals have been studied at temperatures T = 1.8, 4.2, and 114-300 K, and the temperature dependence of the parameters b {/n m } ( T) of the spin Hamiltonian has been found. The behavior of b {2/0}( T) has been analyzed. The spin-phonon and static lattice contributions b {2/0}( F) and b {2/0}( L) to b {2/0}( T) have been revealed. For this purpose, the variation of b {2/0}( L) has been calculated taking into account the thermal shifts of oxygen ions in CaWO4. Similar analysis has been carried out for CaWO4: Eu2+ based on the EPR data of other authors (Bronstein, Voterra and Harvey, Kiefte). It has been shown that at b {2/0}( F) > 0, the variation of b {2/0}( F) as a function of T for these impurity centers is described well by the Pfister model and a sign change of b {2/0}( T) for Eu2+ is determined by thermal expansion of the lattice.

  16. Use of GEANT4 vs. MCNPX for the characterization of a boron-lined neutron detector

    Energy Technology Data Exchange (ETDEWEB)

    Ende, B.M. van der; Atanackovic, J.; Erlandson, A.; Bentoumi, G.

    2016-06-01

    This work compares GEANT4 with MCNPX in the characterization of a boron-lined neutron detector. The neutron energy ranges simulated in this work (0.025 eV to 20 MeV) are the traditional domain of MCNP simulations. This paper addresses the question, how well can GEANT4 and MCNPX be employed for detailed thermal neutron detector characterization? To answer this, GEANT4 and MCNPX have been employed to simulate detector response to a {sup 252}Cf energy spectrum point source, as well as to simulate mono-energetic parallel beam source geometries. The {sup 252}Cf energy spectrum simulation results demonstrate agreement in detector count rate within 3% between the two packages, with the MCNPX results being generally closer to experiment than are those from GEANT4. The mono-energetic source simulations demonstrate agreement in detector response within 5% between the two packages for all neutron energies, and within 1% for neutron energies between 100 eV and 5 MeV. Cross-checks between the two types of simulations using ISO-8529 {sup 252}Cf energy bins demonstrates that MCNPX results are more self-consistent than are GEANT4 results, by 3–4%.

  17. The thermal neutron detection using 4H-SiC detectors with 6LiF conversion layer

    International Nuclear Information System (INIS)

    Zatko, B.; Bohacek, P.; Sekacova, M.; Arbet, J.; Sagatova, A.; Necas, V.

    2016-01-01

    In this paper we have examined 4H-SiC detector using a thermal neutron source and studied its detection properties. The detector was exposed to neutrons generated by 238 Pu-Be radiation source. The detection properties of 4H-SiC detectors were evaluated considering the use of the 6 LiF conversion. We prepared 4H-SiC Schottky contact detectors based on high-quality of epitaxial layer. The current-voltage characteristic show operating region between 100 V and 400 V. The detector was connected to the spectrometric set-up and used for detection of alpha particles from 241 Am. Following the 6 LiF conversion layer was applied on the Schottky contact of detector and the detection of thermal neutrons was performed. We are able to resolve alpha particles and tritons which are products of nuclear reaction between thermal neutrons and conversion layer. Also bare detector was used for neutron detection to clearly show significant influence of the used conversion layer.(authors)

  18. Galactic cosmic ray iron composition

    International Nuclear Information System (INIS)

    Scherzer, R.; Enge, W.; Beaujean, R.

    1980-11-01

    We have studied the isotopic compostition of galactic cosmic ray iron in the energy interval 500-750 MeV/nucleon with a visual track detector system consisting of nuclear emulsion and cellulose-nitrate platic. Stopping iron nuclei were identified from ionization - range measurements in the two detector parts. Cone lengths were measured in the plastic sheets and the residual ranges of the particles were measured in plastic and in emulsion. We have determined the mass of 17 iron nuclei with an uncertainty of about 0.3 amu. The isotopic composition at the detector level was found to be 52 Fe: 53 Fe: 54 Fe: 55 Fe: 56 Fe: 57 Fe: 58 Fe = 0:1: 4:3:8:1:0. These numbers are not in conflict with the assumption that the isotopic composition of cosmic ray iron at the source is similar to the solar system composition. (author)

  19. Measurement of radiation shielding properties of polymer composites by using HPGe detector

    International Nuclear Information System (INIS)

    Gupta, Anil; Pillay, H.C.M.; Kale, P.K.; Datta, D.; Suman, S.K.; Gover, V.

    2014-01-01

    Lead is the most common radiation shield and its composite with polymers can be used as flexible radiation shields for different applications. However, lead is very hazardous and has been found to be associated with neurological disorders, kidney failure and hematotoxicity. Lead free radiation shield material has been developed by synthesizing radiation cross linked PDMS/Bi 2 O 3 polymer composites. In order to have a lead free radiation shield the relevant shielding properties such as linear attenuation, half value thickness (HVT) and tenth value thickness (TVT) have been measured by using HPGe detector. The present study describes the methodology of measurement of the shielding properties of the lead free shield material. In the measurement gamma energies such as 59.537 keV ( 241 Am), 122.061 keV and 136.474 keV ( 57 Co) are taken into consideration

  20. Mass composition studies using the surface detector of the Pierre Auger Observatory

    International Nuclear Information System (INIS)

    Wahlberg, Hernan

    2009-01-01

    The mass composition of ultra-high energy cosmic rays is a critical issue to understand their origin and nature. The Pierre Auger Observatory is a hybrid instrument which provides a powerful environment for the determination of the primary mass. The Surface Detector of the Pierre Auger Observatory alone allows the study of several shower parameters with high discriminating power between primary elements. Novel analysis techniques using different features of signals in the Cherenkov stations are discussed. These are the signal risetime, the azimuthal time asymmetry and the muon density of the showers.

  1. Heavy ion inelastic scattering with a 4π gamma detector

    International Nuclear Information System (INIS)

    Gross, E.E.

    1989-01-01

    Heavy-ion inelastic scattering with a new technique that uses a 4π γ-ray detector in coincidence with charged particle detectors is applied to 24 Mg(200 MeV) + 208 Pb scattering. In addition to differential cross sections, a complete particle-γ angular correlation is obtained for decay of the 2 1 + (1.37 MeV) state of 24 Mg. The data are analyzed in coupled-channels. The correlation data proves to be especially sensitive to the static quadrupole moment. 14 refs., 9 figs

  2. Spent Nuclear Fuel Cask and Storage Monitoring with {sup 4}He Scintillation Fast Neutron Detectors

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Hee jun; Kelley, Ryan P; Jordan, Kelly A [Univ. of Florida, Florida (United States); Lee, Wanno [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Chung, Yong Hyun [Yonsei Univ., Wonju (Korea, Republic of)

    2014-10-15

    With this increasing quantity of spent nuclear fuel being stored at nuclear plants across S. Korea, the demand exists for building a long-term disposal facility. However, the Korean government first requires a detailed plan for the monitoring and certification of spent fuel. Several techniques have been developed and applied for the purpose of spent fuel monitoring, including the digital Cerenkov viewing device (DCVD), spent fuel attribute tester (SFAT), and FORK detector. Conventional gamma measurement methods, however, suffer from a lack of nuclear data and interfering background radiation. To date, the primary method of neutron detection for spent fuel monitoring has been through the use of thermal neutron detectors such as {sup 3}He and BF{sub 3} proportional counters. Unfolding the neutron spectrum becomes extremely complicated. In an attempt to overcome these difficulties, a new fast neutron measurement system is currently being developed at the University of Florida. This system is based on the {sup 4}He scintillation detector invented by Arktis Radiation Detectors Ltd. These detectors are a relatively new technological development and take advantage of the high {sup 4}He cross-section for elastic scattering at fast neutron energies, particularly the resonance around 1 MeV. This novel {sup 4}He scintillation neutron detector is characterized by its low electron density, leading to excellent gamma rejection. This detector also has a fast response time on the order of nanoseconds and most importantly, preserves some neutron energy information since no moderator is required. Additionally, these detectors rely on naturally abundant {sup 4}He as the fill gas. This study proposes a new technique using the neutron spectroscopy features of {sup 4}He scintillation detectors to maintain accountability of spent fuel in storage. This research will support spent fuel safeguards and the detection of fissile material, in order to minimize the risk of nuclear proliferation

  3. Aging measurements on triple-GEM detectors operated with $CF_{4}$-based gas mixtures

    CERN Document Server

    Alfonsi, M; De Simone, P; Murtas, F; Poli Lener, M P; Bonivento, W; Cardini, A; Raspino, D; Saitta, B; Pinci, D; Baccaro, S; 10.1016/j.nuclphysbps.2005.03.054

    2006-01-01

    We present the results of a global irradiation test of full size triple-GEM detectors operated with CF/sub 4/-based gas mixtures. This study has been performed in the framework of an R&D activity on detectors for the innermost region of the first muon station of the LHCb experiment. The prototypes have been irradiated at the Calliope facility of the ENEA-Casaccia with a high intensity 1.25 MeV detectors performances have been measured with X-rays and with a 3 Ge V pion beam at CERN. A SEM analysis on several samples of the detectors has been performed to complete the understanding of the physical processes occurring in a GEM detector during a strong irradiation.

  4. Technical Note: A simulation study on the feasibility of radiotherapy dose enhancement with calcium tungstate and hafnium oxide nano- and microparticles.

    Science.gov (United States)

    Sherck, Nicholas J; Won, You-Yeon

    2017-12-01

    To assess the radiotherapy dose enhancement (RDE) potential of calcium tungstate (CaWO 4 ) and hafnium oxide (HfO 2 ) nano- and microparticles (NPs). A Monte Carlo simulation study was conducted to gauge their respective RDE potentials relative to that of the broadly studied gold (Au) NP. The study was warranted due to the promising clinical and preclinical studies involving both CaWO 4 and HfO 2 NPs as RDE agents in the treatment of various types of cancers. The study provides a baseline RDE to which future experimental RDE trends can be compared to. All three materials were investigated in silico with the software Penetration and Energy Loss of Positrons and Electrons (PENELOPE 2014) developed by Francesc Salvat and distributed in the United States by the Radiation Safety Information Computational Center (RSICC) at Oak Ridge National Laboratory. The work utilizes the extensively studied Au NP as the "gold standard" for a baseline. The key metric used in the evaluation of the materials was the local dose enhancement factor (DEF loc ). An additional metric used, termed the relative enhancement ratio (RER), evaluates material performance at the same mass concentrations. The results of the study indicate that Au has the strongest RDE potential using the DEF loc metric. HfO 2 and CaWO 4 both underperformed relative to Au with lower DEF loc of 2-3 × and 4-100 ×, respectively. The computational investigation predicts the RDE performance ranking to be: Au > HfO 2 > CaWO 4 . © 2017 American Association of Physicists in Medicine.

  5. Heavy ion measurements by use of chemical detectors

    International Nuclear Information System (INIS)

    Huebner, K.; Erzgraeber, G.; Eichhorn, K.

    1980-01-01

    In order to test whether the threshold system polyvinyl alcohol/methyl organe/chloral hydrate/sodium tetraborate permits quantitative detection of individual particles, the chemical detector was irradiated at the JINR U-200 cyclotron with 4 He, 12 C, 18 O, 22 Ne ions having different LET. Irradiations were performed with detectors of four different borax concentrations (the chloral hydrate concentration being constant). The colour change dose Dsub(u) increases linearly with increasing borax concentration and at constant borax concentration with increasing LET. Hence it follows that the G value of dehydrochlorination decreases with increasing LET. Fluence ranges measurable with detectors of different composition are given for the heavy ions studied. (author)

  6. SORO post-simulations of Bruce A Unit 4 in-core flux detector verification tests

    Energy Technology Data Exchange (ETDEWEB)

    Braverman, E.; Nainer, O. [Bruce Power, Nuclear Safety Analysis and Support Dept., Toronto, Ontario (Canada)]. E-mail: Evgeny.Braverman@brucepower.com; Ovidiu.Nainer@brucepower.com

    2004-07-01

    During the plant equipment assessment prior to requesting approval for restart of Bruce A Units 3 and 4 it was determined that all in-core flux detectors needed to be replaced. Flux detector verification tests were performed to confirm that the newly installed detectors had been positioned according to design specifications and that their response closely follows the calculated flux shape changes caused by selected reactivity mechanism movements. By comparing the measured and post-simulated RRS and NOP detector responses to various perturbations, it was confirmed that the new detectors are wired and positioned correctly. (author)

  7. Analysis for In-situ Fission Rate Measurements using 4He Gas Scintillation Detectors

    International Nuclear Information System (INIS)

    Lewis, Jason M.; Raetz, Dominik; Jordan, Kelly A.; Murer, David

    2013-06-01

    Active neutron interrogation is a powerful NDA technique that relies on detecting and analyzing fission neutrons produced in a fuel sample by an interrogating high neutron flux. 4 He scintillation gas fast neutron detectors are investigated in this paper for use in a novel fission rate measurement technique The He-4 detectors have excellent gamma rejection, a fast response time, and give significant information on incident neutron energy allowing for energy cuts to be applied to the detected signal. These features are shown in this work to allow for the detection of prompt fission neutrons in-situ during active neutron interrogation of a 238 U sample. The energy spectrum from three different neutrons sources ( 252 Cf, AmBe, AmLi) is measured using the 4 He detection system and analyzed. An initial response matrix for the detector is determined using these measurements and the kinematic interaction properties of the elastic scattering with the 4 He. (authors)

  8. Comparison of CdZnTe neutron detector models using MCNP6 and Geant4

    Science.gov (United States)

    Wilson, Emma; Anderson, Mike; Prendergasty, David; Cheneler, David

    2018-01-01

    The production of accurate detector models is of high importance in the development and use of detectors. Initially, MCNP and Geant were developed to specialise in neutral particle models and accelerator models, respectively; there is now a greater overlap of the capabilities of both, and it is therefore useful to produce comparative models to evaluate detector characteristics. In a collaboration between Lancaster University, UK, and Innovative Physics Ltd., UK, models have been developed in both MCNP6 and Geant4 of Cadmium Zinc Telluride (CdZnTe) detectors developed by Innovative Physics Ltd. Herein, a comparison is made of the relative strengths of MCNP6 and Geant4 for modelling neutron flux and secondary γ-ray emission. Given the increasing overlap of the modelling capabilities of MCNP6 and Geant4, it is worthwhile to comment on differences in results for simulations which have similarities in terms of geometries and source configurations.

  9. Semiconductor radiation detector

    Science.gov (United States)

    Bell, Zane W.; Burger, Arnold

    2010-03-30

    A semiconductor detector for ionizing electromagnetic radiation, neutrons, and energetic charged particles. The detecting element is comprised of a compound having the composition I-III-VI.sub.2 or II-IV-V.sub.2 where the "I" component is from column 1A or 1B of the periodic table, the "II" component is from column 2B, the "III" component is from column 3A, the "IV" component is from column 4A, the "V" component is from column 5A, and the "VI" component is from column 6A. The detecting element detects ionizing radiation by generating a signal proportional to the energy deposited in the element, and detects neutrons by virtue of the ionizing radiation emitted by one or more of the constituent materials subsequent to capture. The detector may contain more than one neutron-sensitive component.

  10. WORKSHOP: Scintillating fibre detectors

    International Nuclear Information System (INIS)

    Anon.

    1989-01-01

    Scintillating fibre detector development and technology for the proposed US Superconducting Supercollider, SSC, was the subject of a recent workshop at Fermilab, with participation from the high energy physics community and from industry. Sessions covered the current status of fibre technology and fibre detectors, new detector applications, fluorescent materials and scintillation compositions, radiation damage effects, amplification and imaging structures, and scintillation fibre fabrication techniques

  11. Aging measurements on triple-GEM detectors operated with $CF_{4}$- based gas mixtures

    CERN Document Server

    Alfonsi, M; Bencivenni, G; Bonivento, W; Cardini, A; Lener, M P; Murtas, F; Pinci, D; Raspino, D; Saitta, B; De Simone, P

    2004-01-01

    We present the results of a global irradiation test of full size triple-GEM detectors operated with CF/sub 4/-based gas mixtures. This study has been performed in the framework of an R&D activity on detectors for the innermost region of the first muon station of the LHCb experiment. The prototypes have been irradiated at the Calliope facility of the ENEA-Casaccia with a high intensity 1.25 MeV gamma from a /sup 60/Co source. After the irradiation test the detectors performances have been measured with X-rays and with a 3 GeV pion beam at CERN. A SEM analysis on several samples of the detectors has been performed to complete the understanding of the physical processes occurring in the GEM detector during the strong irradiation.

  12. Fission signal detection using helium-4 gas fast neutron scintillation detectors

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, J. M., E-mail: lewisj@ufl.edu; Kelley, R. P.; Jordan, K. A. [Nuclear Engineering Program, University of Florida, Gainesville, Florida 32611 (United States); Murer, D. [Arktis Radiation Detectors Ltd., 8045 Zurich (Switzerland)

    2014-07-07

    We demonstrate the unambiguous detection of the fission neutron signal produced in natural uranium during active neutron interrogation using a deuterium-deuterium fusion neutron generator and a high pressure {sup 4}He gas fast neutron scintillation detector. The energy deposition by individual neutrons is quantified, and energy discrimination is used to differentiate the induced fission neutrons from the mono-energetic interrogation neutrons. The detector can discriminate between different incident neutron energies using pulse height discrimination of the slow scintillation component of the elastic scattering interaction between a neutron and the {sup 4}He atom. Energy histograms resulting from this data show the buildup of a detected fission neutron signal at higher energies. The detector is shown here to detect a unique fission neutron signal from a natural uranium sample during active interrogation with a (d, d) neutron generator. This signal path has a direct application to the detection of shielded nuclear material in cargo and air containers. It allows for continuous interrogation and detection while greatly minimizing the potential for false alarms.

  13. Proposal for a forward spectrometer at the 4π detector

    International Nuclear Information System (INIS)

    Berdermann, E.; Luehning, J.; Lynen, U.; Milkau, U.; Mueller, K.; Sann, H.; Stelzer, H.; Trautmann, W.; Kreutz, P.; Kuehmichel, A.; Pinkenburg, C.; Pochodzalla, J.; Moretto, L.; Mueller, W.F.J.; Wozniak, G.; Imme, G.; Raciti, G.; Adloff, G.C.; Bilwes, B.; Bilwes, R.; Michel, M.; Masse, C.; Rudolf, G.; Scheibling, F.; Stuttge, L.

    1988-03-01

    We propose to complement the 4π detector to be installed at the SIS-ESR facility with a forward spectrometer (ALADiN) capable of detecting and identifying nuclear fragments up to the largest masses and momenta expected at SIS. Positioned behind the time-of-flight wall of the 4π detector the spectrometer should subtend an angular range of approximately ±5 0 in horizontal and at least ±2 0 in vertical direction and thus cover a sufficiently large part of the forward region. In order to satisfy these requirements and to obtain the necessary resolution in mass and momentum the dipole magnet needs, at least, a gap height of 0.5 m, a horizontal acceptance of 1.5 m and a bending power of 2 Tm. The following sections of this proposal start out with a more detailed presentation of the physics motivation which will concentrate on multifragmentation as a new and hitherto unexplored decay mode of nuclear matter under extreme conditions. The description of the spectrometer divides into three sections containing the description of the magnet and the vacuum system, of the detectors needed to track and to identify the fragments, and of the performance of the spectrometer. (orig./HSI)

  14. A comparative study of CaWO4 and rare earth intensifying screens

    International Nuclear Information System (INIS)

    Ambiger, T.Y.; Ayappan, P.

    1978-01-01

    Three brands of commercially available calcium tungstate intensifying screens and a brand of rare earth screen emitting blue light have been used with two types of fast medical x-ray films, one imported and the other indigenous in various film-screen combinations and their sensitometric properties have been determined and compared. The rare earth screen has been found to be about 3 to 4 times faster than the tungstate screens without reduction in contrast. This indicates that the use of rare earth screen in medical radiography will help to reduce the patient dose by the same factor. (M.G.B.)

  15. A neutron activation detector

    International Nuclear Information System (INIS)

    Ambardanishvili, T.S.; Kolomiitsev, M.A.; Zakharina, T.Y.; Dundua, V.J.; Chikhladze, N.V.

    1973-01-01

    The present invention concerns a neutron activation detector made from a moulded and hardened composition. According to the invention, that composition contains an activable substance constituted by at least two chemical elements and/or compounds of at least two chemical elements. Each of these chemical elements is capable of reacting with the neutrons forming radio-active isotopes with vatious levels of energy during desintegration. This neutron detector is mainly suitable for measuring integral thermal neutron and fast neutron fluxes during irradiation of the sample, and also for measuring the intensities of neutron fields [fr

  16. The Cosmic Ray Tracking (CRT) detector system

    International Nuclear Information System (INIS)

    Bernloehr, K.; Gamp, S.; Hermann, G.; Hofmann, W.; Kihm, T.; Knoeppler, J.; Leffers, G.; Matheis, V.; Panter, M.; Trunk, U.; Ulrich, M.; Wolf, T.; Zink, R.; Heintze, J.

    1996-01-01

    The Cosmic Ray Tracking (CRT) project represents a study on the use of tracking detectors of the time projection chamber type to detect secondary cosmic ray particles in extensive air showers. In reconstructing the arrival direction of the primary cosmic ray particles, the CRT detectors take advantage of the angular correlation of secondary particles with the cosmic rays leading to these air showers. In this paper, the detector hardware including the custom-designed electronics system is described in detail. A CRT detector module provides an active area of 2.5 m 2 and allows to measure track directions with a precision of 0.4 circle . It consists of two circular drift chambers of 1.8 m diameter with six sense wires each, and a 10 cm thick iron plate between the two chambers. Each detector has a local electronics box with a readout, trigger, and monitoring system. The detectors can distinguish penetrating muons from other types of charged secondaries. A large detector array could be used to search for γ-ray point sources at energies above several TeV and for studies of the cosmic-ray composition. Ten detectors are in operation at the site of the HEGRA air shower array. (orig.)

  17. Construction of a positron emission tomograph with 2.4 mm detectors

    International Nuclear Information System (INIS)

    McIntyre, J.A.; Sprosst, R.L.; Wang, K.

    1986-01-01

    One-quarter of one ring of a positron tomograph has been constructed. The positron annihilation gamma rays are detected by polished plastic scintillators which direct scintillation light by internal reflection to optical fibers for transmission to the photo-multiplier tubes. By viewing each scintillator with four sets of optical fibers, the number of photomultipliers required for an eight ring tomograph with 1024 detectors per ring (2.4 mm wide detectors) can be reduced from 8192 to 288, and the cost of the tomograph reduced accordingly

  18. The Diogene 4π detector at Saturne

    International Nuclear Information System (INIS)

    Alard, J.P.; Arnold, J.; Augerat, J.; Bastid, N.; Costilhes, J.P.; Crouau, M.; Dupieux, P.; Fraysse, L.; Montarou, G.; Parizet, M.J.; Tamain, J.C.; Valero, J.; Babinet, R.; Marco, N. de; Drouet, M.; Fanet, H.; Fodor, Z.; Girard, J.; Gosset, J.; Laspalles, C.; Lemaire, M.C.; L'Hote, D.; Lucas, B.; Papineau, A.; Poitou, J.; Schimmerling, W.; Terrien, Y.; Valette, O.; Brochard, F.; Gorodetzky, P.; Racca, C.

    1987-01-01

    Diogene, an electronic 4π detector, has been built and installed at the Saturne synchrotron in Saclay. The forward angular range (0 0 -6 0 ) is covered by 48 time-of-flight scintillator telescopes that provide charge identification. The trajectories of fragments emitted at larger angles are recorded in a cylindrical 0.4 m 3 Pictorial Drift Chamber (PDC) surrounding the target. The PDC is inside a 1-T magnetic field; the axis of the PDC cylinder and the magnetic field are parallel to the beam. Good identification has been obtained for both positive and negative π mesons and for hydrogen and helium isotopes. Multiplicities in relativistic nucleus-nucleus reactions up to 40 have been detected, limited mainly by the present electronics. (orig.)

  19. A study of dissipative phenomena using Orion, a 4 π sectorized neutron detector

    International Nuclear Information System (INIS)

    Galin, J.; Guerreau, D.; Morjean, M.; Pouthas, J.; Saint-Laurent, F.; Sokolov, A.; Wang, X.M.; Piasecki, E.; Charvet, J.L.; CEA Centre d'Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette

    1990-01-01

    When studying the behavior of hot nuclei, the challenge is twofold: how are they formed in nucleus-nucleus collisions and how do they decay. For heavy and, thus neutron rich systems a large fraction of the thermalized energy is evacuated by neutron evaporation. Therefore the numbering, event-wise, of neutrons, over 4 π, gives a strong handle on energy dissipation for the different reaction channels. The first neutron measurements of this kind were performed using spherical detectors made of two hemispheres. Since then, a new and larger 4 π detector, ORION, has been designed in order to get information on the spatial distribution of the neutrons. The main characteristics of ORION are described and a few examples are given in order to illustrate the capabilities of such a detector in the study of dissipative collisions

  20. Study of phase equilibria and glass formation in the CaO-WO3-P2O5 system

    International Nuclear Information System (INIS)

    Bielis, I.Ya.

    1980-01-01

    The method of quenching has been used to investigate the liquidus surface of a portion of the CaO-WO 3 -P 2 O 5 system limited by the Ca(PO 3 ) 2 -W 2 O 3 (PO 4 ) 2 and CaWO 4 -Ca 2 P 2 O 7 cross-sections. The primary crystallization fields on the compounds: WO 3 , W 2 O 3 (PO 4 ) 2 , CaWO 4 , Ca 2 P 7 O 7 , Ca(PO 3 ) 2 are separated. The liquidus surface isotherms at 900, 1000, 1100 and 1200 deg C have been plotted on the concentration triangle plane. It has been found that the cross-sections of W 2 O 3 (PO 4 ) 2 -Ca(PO 3 ) 2 , WO 3 -Ca(PO 3 ) 2 , WO 3 -Ca 2 P 2 O 7 and CaWO 4 -Ca 2 P 2 O 7 are eutectic-type quasi-binary systems. The position of the glass transition region in the CaO-WO 3 -P 2 O 5 system has been determined for the treatment temperatures of 1100, 1200 and 1300 deg C and a correlation between the configuration of the glass transition region and the phase diagram of the system has been demonstrated [ru

  1. On the smell of Composition C-4.

    Science.gov (United States)

    Kranz, William; Kitts, Kelley; Strange, Nicholas; Cummins, Joshua; Lotspeich, Erica; Goodpaster, John

    2014-03-01

    In efforts to locate hidden explosives, humans have had few allies as valuable as the explosives-detecting canine. The unrivaled sensitivity and selectivity of the canine nose have combined to make these animals an attractive choice for law enforcement, military, and private security applications. Although the efficacy of trained detector dogs is well-established, the question of which chemical compounds are responsible for causing a dog to recognize a particular odor and alert to it remains a subject of debate for several explosive formulations--including, perhaps most notably, Composition C-4. Previous studies have indicated that cyclohexanone, 2,3-dimethyl-2,3-dinitrobutane, and 2-ethyl-1-hexanol are the chemicals that may cause canines to alert to C-4. This has led to the suggestion that these substances could be used as a substitute for genuine C-4 in the training, testing, and maintenance of explosives-detecting canines. In this paper, we present an alternative view. Using gas chromatography-mass spectrometry with solid phase microextraction as a pre-concentration technique, we have discovered that 2-ethyl-1-hexanol off-gasses not only from C-4, but also from benign sources, such as the common plasticizers bis(2-ethylhexyl)adipate, bis(2-ethylhexyl)sebacate, and bis(2-ethylhexyl)phthalate; as well as several plasticized items common to our everyday world, including PVC tile, PVC pipe, electrical tape, and credit cards. This observation may potentially discourage the use of 2-ethyl-1-hexanol for training purposes. We also present the results of our own canine field trials focused on the detection of C-4. Through the use of contingency tables and statistical testing, we demonstrate the failure of trained law enforcement dogs in our study to respond in any significant way to these potential odor compounds. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  2. The ATLAS Inner Detector commissioning and calibration

    CERN Document Server

    Aad, G.; Abdallah, J.; Abdelalim, A.A.; Abdesselam, A.; Abdinov, O.; Abi, B.; Abolins, M.; Abramowicz, H.; Abreu, H.; Acharya, B.S.; Adams, D.L.; Addy, T.N.; Adelman, J.; Adorisio, C.; Adragna, P.; Adye, T.; Aefsky, S.; Aguilar-Saavedra, J.A.; Aharrouche, M.; Ahlen, S.P.; Ahles, F.; Ahmad, A.; Ahsan, M.; Aielli, G.; Akdogan, T.; Akesson, T.P.A.; Akimoto, G.; Akimov, A.V.; Aktas, A.; Alam, M.S.; Alam, M.A.; Albert, J.; Albrand, S.; Aleksa, M.; Aleksandrov, I.N.; Alexa, C.; Alexander, G.; Alexandre, G.; Alexopoulos, T.; Alhroob, M.; Aliev, M.; Alimonti, G.; Alison, J.; Aliyev, M.; Allport, P.P.; Allwood-Spiers, S.E.; Almond, J.; Aloisio, A.; Alon, R.; Alonso, A.; Alviggi, M.G.; Amako, K.; Amelung, C.; Amorim, A.; Amoros, G.; Amram, N.; Anastopoulos, C.; Andeen, T.; Anders, C.F.; Anderson, K.J.; Andreazza, A.; Andrei, V.; Anduaga, X.S.; Angerami, A.; Anghinolfi, F.; Anjos, N.; Annovi, A.; Antonaki, A.; Antonelli, M.; Antonelli, S.; Antos, J.; Antunovic, B.; Anulli, F.; Aoun, S.; Arabidze, G.; Aracena, I.; Arai, Y.; Arce, A.T.H.; Archambault, J.P.; Arfaoui, S.; Arguin, J-F.; Argyropoulos, T.; Arik, M.; Armbruster, A.J.; Arnaez, O.; Arnault, C.; Artamonov, A.; Arutinov, D.; Asai, M.; Asai, S.; Asfandiyarov, R.; Ask, S.; Asman, B.; Asner, D.; Asquith, L.; Assamagan, K.; Astbury, A.; Astvatsatourov, A.; Atoian, G.; Auerbach, B.; Augsten, K.; Aurousseau, M.; Austin, N.; Avolio, G.; Avramidou, R.; Axen, D.; Ay, C.; Azuelos, G.; Azuma, Y.; Baak, M.A.; Bach, A.M.; Bachacou, H.; Bachas, K.; Backes, M.; Badescu, E.; Bagnaia, P.; Bai, Y.; Bain, T.; Baines, J.T.; Baker, O.K.; Baker, M.D.; Baker, S.; Baltasar Dos, F.Santos Pedrosa; Banas, E.; Banerjee, P.; Banerjee, S.; Banfi, D.; Bangert, A.; Bansal, V.; Baranov, S.P.; Baranov, S.; Barashkou, A.; Barber, T.; Barberio, E.L.; Barberis, D.; Barbero, M.; Bardin, D.Y.; Barillari, T.; Barisonzi, M.; Barklow, T.; Barlow, N.; Barnett, B.M.; Barnett, R.M.; Baroncelli, A.; Barr, A.J.; Barreiro, F.; Guimara, J.Barreiro; Barrillon, P.; Bartoldus, R.; Bartsch, D.; Bates, R.L.; Batkova, L.; Batley, J.R.; Battaglia, A.; Battistin, M.; Bauer, F.; Bawa, H.S.; Bazalova, M.; Beare, B.; Beau, T.; Beauchemin, P.H.; Beccherle, R.; Bechtle, P.; Beck, G.A.; Beck, H.P.; Beckingham, M.; Becks, K.H.; Beddall, A.J.; Beddall, A.; Bednyakov, V.A.; Bee, C.; Begel, M.; Behar Harpaz, S.; Behera, P.K.; Beimforde, M.; Belanger-Champagne, C.; Bell, P.J.; Bell, W.H.; Bella, G.; Bellagamba, L.; Bellina, F.; Bellomo, M.; Belloni, A.; Belotskiy, K.; Beltramello, O.; Ben Ami, S.; Benary, O.; Benchekroun, D.; Bendel, M.; Benedict, B.H.; Benekos, N.; Benhammou, Y.; Benincasa, G.P.; Benjamin, D.P.; Benoit, M.; Bensinger, J.R.; Benslama, K.; Bentvelsen, S.; Beretta, M.; Berge, D.; Bergeaas Kuutmann, E.; Berger, N.; Berghaus, F.; Berglund, E.; Beringer, J.; Bernat, P.; Bernhard, R.; Bernius, C.; Berry, T.; Bertin, A.; Besana, M.I.; Besson, N.; Bethke, S.; Bianchi, R.M.; Bianco, M.; Biebel, O.; Biesiada, J.; Biglietti, M.; Bilokon, H.; Bindi, M.; Binet, S.; Bingul, A.; Bini, C.; Biscarat, C.; Bitenc, U.; Black, K.M.; Blair, R.E.; Blanchard, J-B.; Blanchot, G.; Blocker, C.; Blondel, A.; Blum, W.; Blumenschein, U.; Bobbink, G.J.; Bocci, A.; Boehler, M.; Boek, J.; Boelaert, N.; Boser, S.; Bogaerts, J.A.; Bohm, C.; Bohm, J.; Boisvert, V.; Bold, T.; Boldea, V.; Bondarenko, V.G.; Bondioli, M.; Boonekamp, M.; Bordoni, S.; Borer, C.; Borisov, A.; Borissov, G.; Borjanovic, I.; Borroni, S.; Bos, K.; Boscherini, D.; Bosman, M.; Boterenbrood, H.; Bouchami, J.; Boudreau, J.; Bouhova-Thacker, E.V.; Boulahouache, C.; Bourdarios, C.; Boveia, A.; Boyd, J.; Boyko, I.R.; Bozovic-Jelisavcic, I.; Bracinik, J.; Braem, A.; Branchini, P.; Brandenburg, G.W.; Brandt, A.; Brandt, G.; Brandt, O.; Bratzler, U.; Brau, B.; Brau, J.E.; Braun, H.M.; Brelier, B.; Bremer, J.; Brenner, R.; Bressler, S.; Britton, D.; Brochu, F.M.; Brock, I.; Brock, R.; Brodet, E.; Bromberg, C.; Brooijmans, G.; Brooks, W.K.; Brown, G.; Bruckman de Renstrom, P.A.; Bruncko, D.; Bruneliere, R.; Brunet, S.; Bruni, A.; Bruni, G.; Bruschi, M.; Bucci, F.; Buchanan, J.; Buchholz, P.; Buckley, A.G.; Budagov, I.A.; Budick, B.; Buscher, V.; Bugge, L.; Bulekov, O.; Bunse, M.; Buran, T.; Burckhart, H.; Burdin, S.; Burgess, T.; Burke, S.; Busato, E.; Bussey, P.; Buszello, C.P.; Butin, F.; Butler, B.; Butler, J.M.; Buttar, C.M.; Butterworth, J.M.; Byatt, T.; Caballero, J.; Urban, S.Cabrera; Caforio, D.; Cakir, O.; Calafiura, P.; Calderini, G.; Calfayan, P.; Calkins, R.; Caloba, L.P.; Calvet, D.; Camarri, P.; Cameron, D.; Campana, S.; Campanelli, M.; Canale, V.; Canelli, F.; Canepa, A.; Cantero, J.; Capasso, L.; Capeans Garrido, M.D.M.; Caprini, I.; Caprini, M.; Capua, M.; Caputo, R.; Caramarcu, C.; Cardarelli, R.; Carli, T.; Carlino, G.; Carminati, L.; Caron, B.; Caron, S.; Carrillo Montoya, G.D.; Carron Montero, S.; Carter, A.A.; Carter, J.R.; Carvalho, J.; Casadei, D.; Casado, M.P.; Cascella, M.; Castaneda Hernadez, A.M.; Castaneda-Miranda, E.; Castillo Gimenez, V.; Castro, N.F.; Cataldi, G.; Catinaccio, A.; Catmore, J.R.; Cattai, A.; Cattani, G.; Caughron, S.; Cauz, D.; Cavalleri, P.; Cavalli, D.; Cavalli-Sforza, M.; Cavasinni, V.; Ceradini, F.; Cerqueira, A.S.; Cerri, A.; Cerrito, L.; Cerutti, F.; Cetin, S.A.; Chafaq, A.; Chakraborty, D.; Chan, K.; Chapman, J.D.; Chapman, J.W.; Chareyre, E.; Charlton, D.G.; Chavda, V.; Cheatham, S.; Chekanov, S.; Chekulaev, S.V.; Chelkov, G.A.; Chen, H.; Chen, S.; Chen, X.; Cheplakov, A.; Chepurnov, V.F.; Cherkaoui El, R.Moursli; Tcherniatine, V.; Chesneanu, D.; Cheu, E.; Cheung, S.L.; Chevalier, L.; Chevallier, F.; Chiarella, V.; Chiefari, G.; Chikovani, L.; Childers, J.T.; Chilingarov, A.; Chiodini, G.; Chizhov, V.; Choudalakis, G.; Chouridou, S.; Christidi, I.A.; Christov, A.; Chromek-Burckhart, D.; Chu, M.L.; Chudoba, J.; Ciapetti, G.; Ciftci, A.K.; Ciftci, R.; Cinca, D.; Cindro, V.; Ciobotaru, M.D.; Ciocca, C.; Ciocio, A.; Cirilli, M.; Citterio, M.; Clark, A.; Clark, P.J.; Cleland, W.; Clemens, J.C.; Clement, B.; Clement, C.; Coadou, Y.; Cobal, M.; Coccaro, A.; Cochran, J.; Coggeshall, J.; Cogneras, E.; Colijn, A.P.; Collard, C.; Collins, N.J.; Collins-Tooth, C.; Collot, J.; Colon, G.; Muino, P.Conde; Coniavitis, E.; Conidi, M.C.; Consonni, M.; Constantinescu, S.; Conta, C.; Conventi, F.; Cooke, M.; Cooper, B.D.; Cooper-Sarkar, A.M.; Cooper-Smith, N.J.; Copic, K.; Cornelissen, T.; Corradi, M.; Corriveau, F.; Corso-Radu, A.; Cortes-Gonzalez, A.; Cortiana, G.; Costa, G.; Costa, M.J.; Costanzo, D.; Costin, T.; Cote, D.; Coura Torres, R.; Courneyea, L.; Cowan, G.; Cowden, C.; Cox, B.E.; Cranmer, K.; Cranshaw, J.; Cristinziani, M.; Crosetti, G.; Crupi, R.; Crepe-Renaudin, S.; Cuenca Almenar, C.; Cuhadar Donszelmann, T.; Curatolo, M.; Curtis, C.J.; Cwetanski, P.; Czyczula, Z.; D'Auria, S.; D'Onofrio, M.; D'Orazio, A.; Da Via, C.; Dabrowski, W.; Dai, T.; Dallapiccola, C.; Dam, M.; Danielsson, H.O.; Dannheim, D.; Dao, V.; Darbo, G.; Darlea, G.L.; Davey, W.; Davidek, T.; Davidson, N.; Davidson, R.; Davies, M.; Davison, A.R.; Dawson, I.; Daya, R.K.; De, K.; de Asmundis, R.; De Castro, S.; De Castro, P.E.Faria Salgado; De Cecco, S.; de Graat, J.; De Groot, N.; de Jong, P.; De Mora, L.; De Oliveira, M.Branco; De Pedis, D.; De Salvo, A.; De Sanctis, U.; De Santo, A.; De Vivie De Regie, J.B.; De Zorzi, G.; Dean, S.; Dedovich, D.V.; Degenhardt, J.; Dehchar, M.; Del Papa, C.; Del Peso, J.; Del Prete, T.; Dell'Acqua, A.; Dell'Asta, L.; Della Pietra, M.; della Volpe, D.; Delmastro, M.; Delsart, P.A.; Deluca, C.; Demers, S.; Demichev, M.; Demirkoz, B.; Deng, J.; Deng, W.; Denisov, S.P.; Derkaoui, J.E.; Derue, F.; Dervan, P.; Desch, K.; Deviveiros, P.O.; Dewhurst, A.; DeWilde, B.; Dhaliwal, S.; Dhullipudi, R.; Di Ciaccio, A.; Di Ciaccio, L.; Di Domenico, A.; Di Girolamo, A.; Di Girolamo, B.; Di Luise, S.; Di Mattia, A.; Di Nardo, R.; Di Simone, A.; Di Sipio, R.; Diaz, M.A.; Diblen, F.; Diehl, E.B.; Dietrich, J.; Dietzsch, T.A.; Diglio, S.; Dindar Yagci, K.; Dingfelder, D.J.; Dionisi, C.; Dita, P.; Dita, S.; Dittus, F.; Djama, F.; Djilkibaev, R.; Djobava, T.; Vale, M.A.B.do; Do Valle, A.Wemans; Doan, T.K.O.; Dobos, D.; Dobson, E.; Dobson, M.; Doglioni, C.; Doherty, T.; Dolejsi, J.; Dolenc, I.; Dolezal, Z.; Dolgoshein, B.A.; Dohmae, T.; Donega, M.; Donini, J.; Dopke, J.; Doria, A.; Dos Anjos, A.; Dotti, A.; Dova, M.T.; Doxiadis, A.; Doyle, A.T.; Drasal, Z.; Dris, M.; Dubbert, J.; Duchovni, E.; Duckeck, G.; Dudarev, A.; Dudziak, F.; Duhrssen, M.; Duflot, L.; Dufour, M-A.; Dunford, M.; Duran Yildiz, H.; Dushkin, A.; Duxfield, R.; Dwuznik, M.; Duren, M.; Ebenstein, W.L.; Ebke, J.; Eckweiler, S.; Edmonds, K.; Edwards, C.A.; Egorov, K.; Ehrenfeld, W.; Ehrich, T.; Eifert, T.; Eigen, G.; Einsweiler, K.; Eisenhandler, E.; Ekelof, T.; El Kacimi, M.; Ellert, M.; Elles, S.; Ellinghaus, F.; Ellis, K.; Ellis, N.; Elmsheuser, J.; Elsing, M.; Emeliyanov, D.; Engelmann, R.; Engl, A.; Epp, B.; Eppig, A.; Erdmann, J.; Ereditato, A.; Eriksson, D.; Ermoline, I.; Ernst, J.; Ernst, M.; Ernwein, J.; Errede, D.; Errede, S.; Ertel, E.; Escalier, M.; Escobar, C.; Espinal Curull, X.; Esposito, B.; Etienvre, A.I.; Etzion, E.; Evans, H.; Fabbri, L.; Fabre, C.; Facius, K.; Fakhrutdinov, R.M.; Falciano, S.; Fang, Y.; Fanti, M.; Farbin, A.; Farilla, A.; Farley, J.; Farooque, T.; Farrington, S.M.; Farthouat, P.; Fassnacht, P.; Fassouliotis, D.; Fatholahzadeh, B.; Fayard, L.; Fayette, F.; Febbraro, R.; Federic, P.; Fedin, O.L.; Fedorko, W.; Feligioni, L.; Felzmann, C.U.; Feng, C.; Feng, E.J.; Fenyuk, A.B.; Ferencei, J.; Ferland, J.; Fernandes, B.; Fernando, W.; Ferrag, S.; Ferrando, J.; Ferrara, V.; Ferrari, A.; Ferrari, P.; Ferrari, R.; Ferrer, A.; Ferrer, M.L.; Ferrere, D.; Ferretti, C.; Fiascaris, M.; Fiedler, F.; Filipcic, A.; Filippas, A.; Filthaut, F.; Fincke-Keeler, M.; Fiolhais, M.C.N.; Fiorini, L.; Firan, A.; Fischer, G.; Fisher, M.J.; Flechl, M.; Fleck, I.; Fleckner, J.; Fleischmann, P.; Fleischmann, S.; Flick, T.; Flores Castillo, L.R.; Flowerdew, M.J.; Fonseca Martin, T.; Formica, A.; Forti, A.; Fortin, D.; Fournier, D.; Fowler, A.J.; Fowler, K.; Fox, H.; Francavilla, P.; Franchino, S.; Francis, D.; Franklin, M.; Franz, S.; Fraternali, M.; Fratina, S.; Freestone, J.; French, S.T.; Froeschl, R.; Froidevaux, D.; Frost, J.A.; Fukunaga, C.; Fullana Torregrosa, E.; Fuster, J.; Gabaldon, C.; Gabizon, O.; Gadfort, T.; Gadomski, S.; Gagliardi, G.; Gagnon, P.; Galea, C.; Gallas, E.J.; Gallo, V.; Gallop, B.J.; Gallus, P.; Galyaev, E.; Gan, K.K.; Gao, Y.S.; Gaponenko, A.; Garcia-Sciveres, M.; Garcia, C.; Navarro, J.E.Garcia; Gardner, R.W.; Garelli, N.; Garitaonandia, H.; Garonne, V.; Gatti, C.; Gaudio, G.; Gauzzi, P.; Gavrilenko, I.L.; Gay, C.; Gaycken, G.; Gazis, E.N.; Ge, P.; Gee, C.N.P.; Geich-Gimbel, Ch.; Gellerstedt, K.; Gemme, C.; Genest, M.H.; Gentile, S.; Georgatos, F.; George, S.; Gershon, A.; Ghazlane, H.; Ghodbane, N.; Giacobbe, B.; Giagu, S.; Giakoumopoulou, V.; Giangiobbe, V.; Gianotti, F.; Gibbard, B.; Gibson, A.; Gibson, S.M.; Gilbert, L.M.; Gilchriese, M.; Gilewsky, V.; Gingrich, D.M.; Ginzburg, J.; Giokaris, N.; Giordani, M.P.; Giordano, R.; Giorgi, F.M.; Giovannini, P.; Giraud, P.F.; Girtler, P.; Giugni, D.; Giusti, P.; Gjelsten, B.K.; Gladilin, L.K.; Glasman, C.; Glazov, A.; Glitza, K.W.; Glonti, G.L.; Godfrey, J.; Godlewski, J.; Goebel, M.; Gopfert, T.; Goeringer, C.; Gossling, C.; Gottfert, T.; Goggi, V.; Goldfarb, S.; Goldin, D.; Golling, T.; Gomes, A.; Gomez Fajardo, L.S.; Goncalo, R.; Gonella, L.; Gong, C.; Gonzalez de la Hoz, S.; Gonzalez Silva, M.L.; Gonzalez-Sevilla, S.; Goodson, J.J.; Goossens, L.; Gordon, H.A.; Gorelov, I.; Gorfine, G.; Gorini, B.; Gorini, E.; Gorisek, A.; Gornicki, E.; Gosdzik, B.; Gosselink, M.; Gostkin, M.I.; Gough Eschrich, I.; Gouighri, M.; Goujdami, D.; Goulette, M.P.; Goussiou, A.G.; Goy, C.; Grabowska-Bold, I.; Grafstrom, P.; Grahn, K-J.; Grancagnolo, S.; Grassi, V.; Gratchev, V.; Grau, N.; Gray, H.M.; Gray, J.A.; Graziani, E.; Green, B.; Greenshaw, T.; Greenwood, Z.D.; Gregor, I.M.; Grenier, P.; Griesmayer, E.; Griffiths, J.; Grigalashvili, N.; Grillo, A.A.; Grimm, K.; Grinstein, S.; Grishkevich, Y.V.; Groh, M.; Groll, M.; Gross, E.; Grosse-Knetter, J.; Groth-Jensen, J.; Grybel, K.; Guicheney, C.; Guida, A.; Guillemin, T.; Guler, H.; Gunther, J.; Guo, B.; Gusakov, Y.; Gutierrez, A.; Gutierrez, P.; Guttman, N.; Gutzwiller, O.; Guyot, C.; Gwenlan, C.; Gwilliam, C.B.; Haas, A.; Haas, S.; Haber, C.; Hadavand, H.K.; Hadley, D.R.; Haefner, P.; Hartel, R.; Hajduk, Z.; Hakobyan, H.; Haller, J.; Hamacher, K.; Hamilton, A.; Hamilton, S.; Han, L.; Hanagaki, K.; Hance, M.; Handel, C.; Hanke, P.; Hansen, J.R.; Hansen, J.B.; Hansen, J.D.; Hansen, P.H.; Hansl-Kozanecka, T.; Hansson, P.; Hara, K.; Hare, G.A.; Harenberg, T.; Harrington, R.D.; Harris, O.M.; Harrison, K.; Hartert, J.; Hartjes, F.; Harvey, A.; Hasegawa, S.; Hasegawa, Y.; Hashemi, K.; Hassani, S.; Haug, S.; Hauschild, M.; Hauser, R.; Havranek, M.; Hawkes, C.M.; Hawkings, R.J.; Hayakawa, T.; Hayward, H.S.; Haywood, S.J.; Head, S.J.; Hedberg, V.; Heelan, L.; Heim, S.; Heinemann, B.; Heisterkamp, S.; Helary, L.; Heller, M.; 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Robertson, S.H.; Robichaud-Veronneau, A.; Robinson, D.; Robinson, J.E.M.; Robinson, M.; Robson, A.; Rocha de Lima, J.G.; Roda, C.; Roda Dos, D.Santos; Rodriguez, D.; Rodriguez Garcia, Y.; Roe, S.; Rohne, O.; Rojo, V.; Rolli, S.; Romaniouk, A.; Romanov, V.M.; Romeo, G.; Romero Maltrana, D.; Roos, L.; Ros, E.; Rosati, S.; Rosenbaum, G.A.; Rosselet, L.; Rossetti, V.; Rossi, L.P.; Rotaru, M.; Rothberg, J.; Rousseau, D.; Royon, C.R.; Rozanov, A.; Rozen, Y.; Ruan, X.; Ruckert, B.; Ruckstuhl, N.; Rud, V.I.; Rudolph, G.; Ruhr, F.; Ruggieri, F.; Ruiz-Martinez, A.; Rumyantsev, L.; Rurikova, Z.; Rusakovich, N.A.; Rutherfoord, J.P.; Ruwiedel, C.; Ruzicka, P.; Ryabov, Y.F.; Ryan, P.; Rybkin, G.; Rzaeva, S.; Saavedra, A.F.; Sadrozinski, H.F-W.; Sadykov, R.; Safai Tehrani, F.; Sakamoto, H.; Salamanna, G.; Salamon, A.; Saleem, M.S.; Salihagic, D.; Salnikov, A.; Salt, J.; Salvachua Ferrando, B.M.; Salvatore, D.; Salvatore, F.; Salvucci, A.; Salzburger, A.; Sampsonidis, D.; Samset, B.H.; Sanchis Lozano, M.A.; Sandaker, H.; Sander, H.G.; Sanders, M.P.; Sandhoff, M.; Sandhu, P.; Sandstroem, R.; Sandvoss, S.; Sankey, D.P.C.; Sanny, B.; Sansoni, A.; Santamarina Rios, C.; Santoni, C.; Santonico, R.; Saraiva, J.G.; Sarangi, T.; Sarkisyan-Grinbaum, E.; Sarri, F.; Sasaki, O.; Sasao, N.; Satsounkevitch, I.; Sauvage, G.; Savard, P.; Savine, A.Y.; Savinov, V.; Sawyer, L.; Saxon, D.H.; Says, L.P.; Sbarra, C.; Sbrizzi, A.; Scannicchio, D.A.; Schaarschmidt, J.; Schacht, P.; Schafer, U.; Schaetzel, S.; Schaffer, A.C.; Schaile, D.; Schamberger, R.D.; Schamov, A.G.; Scharf, V.; Schegelsky, V.A.; Scheirich, D.; Schernau, M.; Scherzer, M.I.; Schiavi, C.; Schieck, J.; Schioppa, M.; Schlenker, S.; Schmidt, E.S.; Schmieden, K.; Schmitt, C.; Schmitz, M.; Schonig, A.; Schott, M.; Schouten, D.; Schovancova, J.; Schram, M.; Schreiner, A.; Schroeder, C.; Schroer, N.; Schroers, M.; Schultes, J.; Schultz-Coulon, H.C.; Schumacher, J.W.; Schumacher, M.; Schumm, B.A.; Schune, Ph.; Schwanenberger, C.; Schwartzman, A.; Schwemling, Ph.; Schwienhorst, R.; Schwierz, R.; Schwindling, J.; Scott, W.G.; Searcy, J.; Sedykh, E.; Segura, E.; Seidel, S.C.; Seiden, A.; Seifert, F.; Seixas, J.M.; Sekhniaidze, G.; Seliverstov, D.M.; Sellden, B.; Semprini-Cesari, N.; Serfon, C.; Serin, L.; Seuster, R.; Severini, H.; Sevior, M.E.; Sfyrla, A.; Shabalina, E.; Shamim, M.; Shan, L.Y.; Shank, J.T.; Shao, Q.T.; Shapiro, M.; Shatalov, P.B.; Shaw, K.; Sherman, D.; Sherwood, P.; Shibata, A.; Shimojima, M.; Shin, T.; Shmeleva, A.; Shochet, M.J.; Shupe, M.A.; Sicho, P.; Sidoti, A.; Siegert, F.; Siegrist, J.; Sijacki, Dj.; Silbert, O.; Silva, J.; Silver, Y.; Silverstein, D.; Silverstein, S.B.; Simak, V.; Simic, Lj.; Simion, S.; Simmons, B.; Simonyan, M.; Sinervo, P.; Sinev, N.B.; Sipica, V.; Siragusa, G.; Sisakyan, A.N.; Sivoklokov, S.Yu.; Sjoelin, J.; Sjursen, T.B.; Skovpen, K.; Skubic, P.; Slater, M.; Slavicek, T.; Sliwa, K.; Sloper, J.; Sluka, T.; Smakhtin, V.; Smirnov, S.Yu.; Smirnov, Y.; Smirnova, L.N.; Smirnova, O.; Smith, B.C.; Smith, D.; Smith, K.M.; Smizanska, M.; Smolek, K.; Snesarev, A.A.; Snow, S.W.; Snow, J.; Snuverink, J.; Snyder, S.; Soares, M.; Sobie, R.; Sodomka, J.; Soffer, A.; Solans, C.A.; Solar, M.; Solc, J.; Solfaroli Camillocci, E.; Solodkov, A.A.; Solovyanov, O.V.; Soluk, R.; Sondericker, J.; Sopko, V.; Sopko, B.; Sosebee, M.; Soukharev, A.; Spagnolo, S.; Spano, F.; Spencer, E.; Spighi, R.; Spigo, G.; Spila, F.; Spiwoks, R.; Spousta, M.; Spreitzer, T.; Spurlock, B.; Denis, R.D.St.; Stahl, T.; Stahlman, J.; Stamen, R.; Stancu, S.N.; Stanecka, E.; Stanek, R.W.; Stanescu, C.; Stapnes, S.; Starchenko, E.A.; Stark, J.; Staroba, P.; Starovoitov, P.; Stastny, J.; Stavina, P.; Steele, G.; Steinbach, P.; Steinberg, P.; Stekl, I.; Stelzer, B.; Stelzer, H.J.; Stelzer-Chilton, O.; Stenzel, H.; Stevenson, K.; Stewart, G.; Stockton, M.C.; Stoerig, K.; Stoicea, G.; Stonjek, S.; Strachota, P.; Stradling, A.R.; Straessner, A.; Strandberg, J.; Strandberg, S.; Strandlie, A.; Strauss, M.; Strizenec, P.; Strohmer, R.; Strom, D.M.; Stroynowski, R.; Strube, J.; Stugu, B.; Sturm, P.; Soh, D.A.; Su, D.; Sugaya, Y.; Sugimoto, T.; Suhr, C.; Suk, M.; Sulin, V.V.; Sultansoy, S.; Sumida, T.; Sun, X.H.; Sundermann, J.E.; Suruliz, K.; Sushkov, S.; Susinno, G.; Sutton, M.R.; Suzuki, T.; Suzuki, Y.; Sykora, I.; Sykora, T.; Szymocha, T.; Sanchez, J.; Ta, D.; Tackmann, K.; Taffard, A.; Tafirout, R.; Taga, A.; Takahashi, Y.; Takai, H.; Takashima, R.; Takeda, H.; Takeshita, T.; Talby, M.; Talyshev, A.; Tamsett, M.C.; Tanaka, J.; Tanaka, R.; Tanaka, S.; Tanaka, S.; Tapprogge, S.; Tardif, D.; Tarem, S.; Tarrade, F.; Tartarelli, G.F.; Tas, P.; Tasevsky, M.; Tassi, E.; Tatarkhanov, M.; Taylor, C.; Taylor, F.E.; Taylor, G.N.; Taylor, R.P.; Taylor, W.; Teixeira-Dias, P.; Ten Kate, H.; Teng, P.K.; Tennenbaum-Katan, Y.D.; Terada, S.; Terashi, K.; Terron, J.; Terwort, M.; Testa, M.; Teuscher, R.J.; Therhaag, J.; Thioye, M.; Thoma, S.; Thomas, J.P.; Thompson, E.N.; Thompson, P.D.; Thompson, P.D.; Thompson, R.J.; Thompson, A.S.; Thomson, E.; Thun, R.P.; Tic, T.; Tikhomirov, V.O.; Tikhonov, Y.A.; Tipton, P.; Tique Aires, F.J.Viegas; Tisserant, S.; Toczek, B.; Todorov, T.; Todorova-Nova, S.; Toggerson, B.; Tojo, J.; Tokar, S.; Tokushuku, K.; Tollefson, K.; Tomasek, L.; Tomasek, M.; Tomoto, M.; Tompkins, L.; Toms, K.; Tonoyan, A.; Topfel, C.; Topilin, N.D.; Torchiani, I.; Torrence, E.; Pastor, E.Torro; Toth, J.; Touchard, F.; Tovey, D.R.; Trefzger, T.; Tremblet, L.; Tricoli, A.; Trigger, I.M.; Trincaz-Duvoid, S.; Trinh, T.N.; Tripiana, M.F.; Triplett, N.; Trischuk, W.; Trivedi, A.; Trocme, B.; Troncon, C.; Trzupek, A.; Tsarouchas, C.; Tseng, J.C-L.; Tsiakiris, M.; Tsiareshka, P.V.; Tsionou, D.; Tsipolitis, G.; Tsiskaridze, V.; Tskhadadze, E.G.; Tsukerman, I.I.; Tsulaia, V.; Tsung, J.W.; Tsuno, S.; Tsybychev, D.; Tuggle, J.M.; Turecek, D.; Turk Cakir, I.; Turlay, E.; Tuts, P.M.; Twomey, M.S.; Tylmad, M.; Tyndel, M.; Uchida, K.; Ueda, I.; Ueno, R.; Ugland, M.; Uhlenbrock, M.; Uhrmacher, M.; Ukegawa, F.; Unal, G.; Undrus, A.; Unel, G.; Unno, Y.; Urbaniec, D.; Urkovsky, E.; Urquijo, P.; Urrejola, P.; Usai, G.; Uslenghi, M.; Vacavant, L.; Vacek, V.; Vachon, B.; Vahsen, S.; Valente, P.; Valentinetti, S.; Valkar, S.; Valladolid Gallego, E.; Vallecorsa, S.; Valls Ferrer, J.A.; Van Berg, R.; van der Graaf, H.; van der Kraaij, E.; van der Poel, E.; van der Ster, D.; van Eldik, N.; van Gemmeren, P.; van Kesteren, Z.; van Vulpen, I.; Vandelli, W.; Vaniachine, A.; Vankov, P.; Vannucci, F.; Vari, R.; Varnes, E.W.; Varouchas, D.; Vartapetian, A.; Varvell, K.E.; Vasilyeva, L.; Vassilakopoulos, V.I.; Vazeille, F.; Vellidis, C.; Veloso, F.; Veneziano, S.; Ventura, A.; Ventura, D.; Venturi, M.; Venturi, N.; Vercesi, V.; Verducci, M.; Verkerke, W.; Vermeulen, J.C.; Vetterli, M.C.; Vichou, I.; Vickey, T.; Viehhauser, G.H.A.; Villa, M.; Villani, E.G.; Villaplana Perez, M.; Vilucchi, E.; Vincter, M.G.; Vinek, E.; Vinogradov, V.B.; Viret, S.; Virzi, J.; Vitale, A.; Vitells, O.; Vivarelli, I.; Vives Vaque, F.; Vlachos, S.; Vlasak, M.; Vlasov, N.; Vogel, A.; Vokac, P.; Volpi, M.; von der Schmitt, H.; von Loeben, J.; von Radziewski, H.; von Toerne, E.; Vorobel, V.; Vorwerk, V.; Vos, M.; Voss, R.; Voss, T.T.; Vossebeld, J.H.; Vranjes, N.; Vranjes Milosavljevic, M.; Vrba, V.; Vreeswijk, M.; Vu Anh, T.; Vudragovic, D.; Vuillermet, R.; Vukotic, I.; Wagner, P.; Walbersloh, J.; Walder, J.; Walker, R.; Walkowiak, W.; Wall, R.; Wang, C.; Wang, H.; Wang, J.; Wang, S.M.; Warburton, A.; Ward, C.P.; Warsinsky, M.; Wastie, R.; Watkins, P.M.; Watson, A.T.; Watson, M.F.; Watts, G.; Watts, S.; Waugh, A.T.; Waugh, B.M.; Weber, M.D.; Weber, M.; Weber, M.S.; Weber, P.; Weidberg, A.R.; Weingarten, J.; Weiser, C.; Wellenstein, H.; Wells, P.S.; Wen, M.; Wenaus, T.; Wendler, S.; Wengler, T.; Wenig, S.; Wermes, N.; Werner, M.; Werner, P.; Werth, M.; Werthenbach, U.; Wessels, M.; Whalen, K.; White, A.; White, M.J.; White, S.; Whitehead, S.R.; Whiteson, D.; Whittington, D.; Wicek, F.; Wicke, D.; Wickens, F.J.; Wiedenmann, W.; Wielers, M.; Wienemann, P.; Wiglesworth, C.; Wiik, L.A.M.; Wildauer, A.; Wildt, M.A.; Wilkens, H.G.; Williams, E.; Williams, H.H.; Willocq, S.; Wilson, J.A.; Wilson, M.G.; Wilson, A.; Wingerter-Seez, I.; Winklmeier, F.; Wittgen, M.; Wolter, M.W.; Wolters, H.; Wosiek, B.K.; Wotschack, J.; Woudstra, M.J.; Wraight, K.; Wright, C.; Wright, D.; Wrona, B.; Wu, S.L.; Wu, X.; Wulf, E.; Wynne, B.M.; Xaplanteris, L.; Xella, S.; Xie, S.; Xu, D.; Xu, N.; Yamada, M.; Yamamoto, A.; Yamamoto, K.; Yamamoto, S.; Yamamura, T.; Yamaoka, J.; Yamazaki, T.; Yamazaki, Y.; Yan, Z.; Yang, H.; Yang, U.K.; Yang, Z.; Yao, W-M.; Yao, Y.; Yasu, Y.; Ye, J.; Ye, S.; Yilmaz, M.; Yoosoofmiya, R.; Yorita, K.; Yoshida, R.; Young, C.; Youssef, S.P.; Yu, D.; Yu, J.; Yuan, L.; Yurkewicz, A.; Zaidan, R.; Zaitsev, A.M.; Zajacova, Z.; Zambrano, V.; Zanello, L.; Zaytsev, A.; Zeitnitz, C.; Zeller, M.; Zemla, A.; Zendler, C.; Zenin, O.; Zenis, T.; Zenonos, Z.; Zenz, S.; Zerwas, D.; della Porta, G.Zevi; Zhan, Z.; Zhang, H.; Zhang, J.; Zhang, Q.; Zhang, X.; Zhao, L.; Zhao, T.; Zhao, Z.; Zhemchugov, A.; Zhong, J.; Zhou, B.; Zhou, N.; Zhou, Y.; Zhu, C.G.; Zhu, H.; Zhu, Y.; Zhuang, X.; Zhuravlov, V.; Zimmermann, R.; Zimmermann, S.; Zimmermann, S.; Ziolkowski, M.; Zivkovic, L.; Zobernig, G.; Zoccoli, A.; zur Nedden, M.

    2010-01-01

    The ATLAS Inner Detector is a composite tracking system consisting of silicon pixels, silicon strips and straw tubes in a 2 T magnetic field. Its installation was completed in August 2008 and the detector took part in data- taking with single LHC beams and cosmic rays. The initial detector operation, hardware commissioning and in-situ calibrations are described. Tracking performance has been measured with 7.6 million cosmic-ray events, collected using a tracking trigger and reconstructed with modular pattern-recognition and fitting software. The intrinsic hit efficiency and tracking trigger efficiencies are close to 100%. Lorentz angle measurements for both electrons and holes, specific energy-loss calibration and transition radiation turn-on measurements have been performed. Different alignment techniques have been used to reconstruct the detector geometry. After the initial alignment, a transverse impact parameter resolution of 22.1+/-0.9 {\\mu}m and a relative momentum resolution {\\sigma}p/p = (4.83+/-0.16)...

  3. The simulation of the LANFOS-H food radiation contamination detector using Geant4 package

    Science.gov (United States)

    Piotrowski, Lech Wiktor; Casolino, Marco; Ebisuzaki, Toshikazu; Higashide, Kazuhiro

    2015-02-01

    Recent incident in the Fukushima power plant caused a growing concern about the radiation contamination and resulted in lowering the Japanese limits for the permitted amount of 137Cs in food to 100 Bq/kg. To increase safety and ease the concern we are developing LANFOS (Large Food Non-destructive Area Sampler)-a compact, easy to use detector for assessment of radiation in food. Described in this paper LANFOS-H has a 4 π coverage to assess the amount of 137Cs present, separating it from the possible 40K food contamination. Therefore, food samples do not have to be pre-processed prior to a test and can be consumed after measurements. It is designed for use by non-professionals in homes and small institutions such as schools, showing safety of the samples, but can be also utilized by specialists providing radiation spectrum. Proper assessment of radiation in food in the apparatus requires estimation of the γ conversion factor of the detectors-how many γ photons will produce a signal. In this paper we show results of the Monte Carlo estimation of this factor for various approximated shapes of fish, vegetables and amounts of rice, performed with Geant4 package. We find that the conversion factor combined from all the detectors is similar for all food types and is around 37%, varying maximally by 5% with sample length, much less than for individual detectors. The different inclinations and positions of samples in the detector introduce uncertainty of 1.4%. This small uncertainty validates the concept of a 4 π non-destructive apparatus.

  4. ISABELLE. Volume 4. Detector R and D

    International Nuclear Information System (INIS)

    1981-01-01

    Workshop participants were asked to assess the current status of detector R and D in terms of the specific needs for ISABELLE experiments: the demands of high particle rates, extremely selective triggers on complex and rare events, and the economics of large detector systems. The detailed results of working groups convened to consider specific areas of detector development are presented. The key points of this assessment, as regards the continuing R and D program for ISABELLE are summarized here. Twenty-six items from the volume were prepared separately for the data base, along with five items previously prepared

  5. ISABELLE. Volume 4. Detector R and D

    Energy Technology Data Exchange (ETDEWEB)

    1981-01-01

    Workshop participants were asked to assess the current status of detector R and D in terms of the specific needs for ISABELLE experiments: the demands of high particle rates, extremely selective triggers on complex and rare events, and the economics of large detector systems. The detailed results of working groups convened to consider specific areas of detector development are presented. The key points of this assessment, as regards the continuing R and D program for ISABELLE are summarized here. Twenty-six items from the volume were prepared separately for the data base, along with five items previously prepared. (GHT)

  6. Department of Radiation Detectors - Overview

    International Nuclear Information System (INIS)

    Piekoszewski, J.

    1997-01-01

    Work carried out in 1996 in the Department of Radiation Detectors concentrated on three subjects: (i) Semiconductor Detectors (ii) X-ray Tube Generators (iii) Material Modification Using Ion and Plasma Beams. The Departamental objectives are: a search for new types of detectors, adapting modern technologies (especially of industrial microelectronics) to detector manufacturing, producing unique detectors tailored for physics experiments, manufacturing standard detectors for radiation measuring instruments. These objectives were accomplished in 1996 by: research on unique detectors for nuclear physics (e.g. a spherical set of particle detectors silicon ball), detectors for particle identification), development of technology of high-resistivity silicon detectors HRSi (grant proposal), development of thermoelectric cooling systems (grant proposal), research on p-i-n photodiode-based personal dosimeters, study of applicability of industrial planar technology in producing detectors, manufacturing detectors developed in previous years, re-generating and servicing customer detectors of various origin. The Department conducts research on the design and technology involved in producing X-ray generators based on X-ray tubes of special construction. Various tube models and their power supplies were developed. Some work has also been devoted to the detection and dosimetry of X-rays. X-ray tube generators are applied to non-destructive testing and are components of analytical systems such as: X-ray fluorescence chemical composition analysis, gauges of layer thickness and composition stress measurements, on-line control of processes, others where an X-ray tube may replace a radio-isotope source. In 1996, the Department: reviewed the domestic demand for X-ray generators, developed an X-ray generator for diagnosis of ostheroporosis of human limbs, prepared a grant proposal for the development of a new instrument for radiotherapy, the so-called needle-like X-ray tube. (author)

  7. Department of Radiation Detectors - Overview

    Energy Technology Data Exchange (ETDEWEB)

    Piekoszewski, J. [Soltan Inst. for Nuclear Studies, Otwock-Swierk (Poland)

    1997-12-31

    Work carried out in 1996 in the Department of Radiation Detectors concentrated on three subjects: (i) Semiconductor Detectors (ii) X-ray Tube Generators (iii) Material Modification Using Ion and Plasma Beams. The Departamental objectives are: a search for new types of detectors, adapting modern technologies (especially of industrial microelectronics) to detector manufacturing, producing unique detectors tailored for physics experiments, manufacturing standard detectors for radiation measuring instruments. These objectives were accomplished in 1996 by: research on unique detectors for nuclear physics (e.g. a spherical set of particle detectors silicon ball), detectors for particle identification), development of technology of high-resistivity silicon detectors HRSi (grant proposal), development of thermoelectric cooling systems (grant proposal), research on p-i-n photodiode-based personal dosimeters, study of applicability of industrial planar technology in producing detectors, manufacturing detectors developed in previous years, re-generating and servicing customer detectors of various origin. The Department conducts research on the design and technology involved in producing X-ray generators based on X-ray tubes of special construction. Various tube models and their power supplies were developed. Some work has also been devoted to the detection and dosimetry of X-rays. X-ray tube generators are applied to non-destructive testing and are components of analytical systems such as: X-ray fluorescence chemical composition analysis, gauges of layer thickness and composition stress measurements, on-line control of processes, others where an X-ray tube may replace a radio-isotope source. In 1996, the Department: reviewed the domestic demand for X-ray generators, developed an X-ray generator for diagnosis of ostheroporosis of human limbs, prepared a grant proposal for the development of a new instrument for radiotherapy, the so-called needle-like X-ray tube. (author).

  8. A Supra-Thermal Energetic Particle detector (STEP) for composition measurements in the range approximately 20 keV/nucleon to 1 MeV/nucleon

    Science.gov (United States)

    Mason, G. M.; Gloeckler, G.

    1981-01-01

    A detector system is described, employing a time-of-flight versus residual energy technique which allows measurement of particle composition (H-Fe), energy spectral and anisotropies in an energy range unaccessible with previously flown sensors. Applications of this method to measurements of the solar wind ion composition are discussed.

  9. Calibration of detector efficiency of neutron detector

    International Nuclear Information System (INIS)

    Guo Hongsheng; He Xijun; Xu Rongkun; Peng Taiping

    2001-01-01

    BF 3 neutron detector has been set up. Detector efficiency is calibrated by associated particle technique. It is about 3.17 x 10 -4 (1 +- 18%). Neutron yield of neutron generator per pulse (10 7 /pulse) is measured by using the detector

  10. Simulations of the Response of the Cluster Detector/Scintillator Wall for the 4π facility at SIS/ESR using the GEANT Detector program

    International Nuclear Information System (INIS)

    Herrmann, N.; Maguire, C.F.; Cerruti, C.; Coffin, J.P.; Fintz, P.; Guillaume, G.; Jundt, F.; Rami, F.; Tezkratt, R.; Wagner, P.

    1990-01-01

    The expected response of the cluster detector/scintillator wall of the SIS/ESR 4π facility has been investigated with the use of the GEANT detector program and the FREESCO event generator code. Results are presented and discussed. It is shown in particular that the efficiency of the track reconstruction method should be acceptable

  11. Preparation and characterization of NiW-nHA composite catalyst for hydrocracking

    Science.gov (United States)

    Zhou, Gang; Hou, Yongzhao; Liu, Lei; Liu, Hongru; Liu, Can; Liu, Jing; Qiao, Huiting; Liu, Wenyong; Fan, Yubo; Shen, Shituan; Rong, Long

    2012-11-01

    The synthesis, characterization and catalytic capability of the NiW-nano-hydroxyapatite (NiW-nHA) composite were investigated in this paper. The NiW-nHA catalyst was prepared by a co-precipitation method. Then Fourier transform infrared (FT-IR) spectroscopy, transmission electron microscopy (TEM), X-ray diffraction (XRD) and energy dispersive spectroscopy (EDX) were used to analyze this material. In addition, the catalytic capacity of the NiW-nHA composite was also examined by FT-IR and gas chromatography (GC). The results of FT-IR analysis indicated that Ni, W and nHA combined closely. TEM observation revealed that this catalyst was needle shaped and the crystal retained a nanometer size. XRD data also suggested that a new phase of CaWO4 appeared and the lattice parameters of nHA changed in this system. nHA was the carrier of metals. The rates of Ni/W-loading were 73.24% and 65.99% according to the EDX data, respectively. Furthermore, the conversion of 91.88% Jatropha oil was achieved at 360 °C and 3 MPa h-1 over NiW-nHA catalyst. The straight chain alkanes ranging from C15 to C18 were the main components in the production. The yield of C15-C18 alkanes was up to 83.56 wt%. The reaction pathway involved hydrocracking of the C&z.dbd;C bonds of these triglycerides from Jatropha oil. This paper developed a novel non-sulfided catalyst to obtain a ``green biofuel'' from vegetable oil.

  12. Limits on Momentum-Dependent Asymmetric Dark Matter with CRESST-II.

    Science.gov (United States)

    Angloher, G; Bento, A; Bucci, C; Canonica, L; Defay, X; Erb, A; Feilitzsch, F V; Ferreiro Iachellini, N; Gorla, P; Gütlein, A; Hauff, D; Jochum, J; Kiefer, M; Kluck, H; Kraus, H; Lanfranchi, J-C; Loebell, J; Münster, A; Pagliarone, C; Petricca, F; Potzel, W; Pröbst, F; Reindl, F; Schäffner, K; Schieck, J; Schönert, S; Seidel, W; Stodolsky, L; Strandhagen, C; Strauss, R; Tanzke, A; Trinh Thi, H H; Türkoğlu, C; Uffinger, M; Ulrich, A; Usherov, I; Wawoczny, S; Willers, M; Wüstrich, M; Zöller, A

    2016-07-08

    The usual assumption in direct dark matter searches is to consider only the spin-dependent or spin-independent scattering of dark matter particles. However, especially in models with light dark matter particles O(GeV/c^{2}), operators which carry additional powers of the momentum transfer q^{2} can become dominant. One such model based on asymmetric dark matter has been invoked to overcome discrepancies in helioseismology and an indication was found for a particle with a preferred mass of 3  GeV/c^{2} and a cross section of 10^{-37}  cm^{2}. Recent data from the CRESST-II experiment, which uses cryogenic detectors based on CaWO_{4} to search for nuclear recoils induced by dark matter particles, are used to constrain these momentum-dependent models. The low energy threshold of 307 eV for nuclear recoils of the detector used, allows us to rule out the proposed best fit value above.

  13. Deuterium-tritium neutron yield measurements with the 4.5 m neutron-time-of-flight detectors at NIF.

    Science.gov (United States)

    Moran, M J; Bond, E J; Clancy, T J; Eckart, M J; Khater, H Y; Glebov, V Yu

    2012-10-01

    The first several campaigns of laser fusion experiments at the National Ignition Facility (NIF) included a family of high-sensitivity scintillator∕photodetector neutron-time-of-flight (nTOF) detectors for measuring deuterium-deuterium (DD) and DT neutron yields. The detectors provided consistent neutron yield (Y(n)) measurements from below 10(9) (DD) to nearly 10(15) (DT). The detectors initially demonstrated detector-to-detector Y(n) precisions better than 5%, but lacked in situ absolute calibrations. Recent experiments at NIF now have provided in situ DT yield calibration data that establish the absolute sensitivity of the 4.5 m differential tissue harmonic imaging (DTHI) detector with an accuracy of ± 10% and precision of ± 1%. The 4.5 m nTOF calibration measurements also have helped to establish improved detector impulse response functions and data analysis methods, which have contributed to improving the accuracy of the Y(n) measurements. These advances have also helped to extend the usefulness of nTOF measurements of ion temperature and downscattered neutron ratio (neutron yield 10-12 MeV divided by yield 13-15 MeV) with other nTOF detectors.

  14. Determination of the 4 mm Gamma Knife helmet relative output factor using a variety of detectors

    International Nuclear Information System (INIS)

    Tsai, J.-S.; Rivard, Mark J.; Engler, Mark J.; Mignano, John E.; Wazer, David E.; Shucart, William A.

    2003-01-01

    Though the 4 mm Gamma Knife helmet is used routinely, there is disagreement in the Gamma Knife users community on the value of the 4 mm helmet relative output factor. A range of relative output factors is used, and this variation may impair observations of dose response and optimization of prescribed dose. To study this variation, measurements were performed using the following radiation detectors: silicon diode, diamond detector, radiographic film, radiochromic film, and TLD cubes. To facilitate positioning of the silicon diode and diamond detector, a three-dimensional translation micrometer was used to iteratively determine the position of maximum detector response. Positioning of the films and TLDs was accomplished by manufacturing custom holders for each technique. Results from all five measurement techniques indicate that the 4 mm helmet relative output factor is 0.868±0.014. Within the experimental uncertainties, this value is in good agreement with results obtained by other investigators using diverse techniques

  15. Proportional 4π detector with an electric field of axial symmetry

    International Nuclear Information System (INIS)

    Guevara, E.A.; Costello, E.D.

    1984-01-01

    A gas-flow proportional 4π counter, with an electric field of axial symmetry, designed and constructed by the authors, whose characteristics allow to work at positive gaseous pressure, is described. Based on the results from the measurements performed, the new detector proved to be suitable for the absolute calibration of beta-emitting radioactive sources and that the accuracy of the determinations can be compared with that achieved at metrologic laboratories of recognized accuracy. The slight dependence of the detector's efficiency on the nuclide's beta energy within the limits studied and its good performance for the measurements of non-punctual sources, are emphasized. Moreover, the spectra obtained, the disintegration schemes and the type of beta transition for each calibrated nuclide are presented. Some detector's parameters of certain interest, the capacity of the chambers in air and the loss of current at the working voltage are included in an annex. (M.E.L.) [es

  16. Construction of the CDF silicon vertex detector

    International Nuclear Information System (INIS)

    Skarha, J.; Barnett, B.; Boswell, C.; Snider, F.; Spies, A.; Tseng, J.; Vejcik, S.; Carter, H.; Flaugher, B.; Gonzales, B.; Hrycyk, M.; Nelson, C.; Segler, S.; Shaw, T.; Tkaczyk, S.; Turner, K.; Wesson, T.; Carithers, W.; Ely, R.; Haber, C.; Holland, S.; Kleinfelder, S.; Merrick, T.; Schneider, O.; Wester, W.; Wong, M.; Amidei, D.; Derwent, P.; Gold, M.; Matthews, J.; Bacchetta, N.; Bisello, D.; Busetto, G.; Castro, A.; Loreti, M.; Pescara, L.; Bedeschi, F.; Bolognesi, V.; Dell'Agnello, S.; Galeotti, S.; Mariotti, M.; Menzione, A.; Punzi, G.; Raffaelli, F.; Risotri, L.; Tartarelli, F.; Turini, N.; Wenzel, H.; Zetti, F.; Bailey, M.; Garfinkel, A.; Shaw, N.; Tipton, P.; Watts, G.

    1992-04-01

    Technical details and methods used in constructing the CDF silicon vertex detector are presented. This description includes a discussion of the foam-carbon fiber composite structure used to silicon microstrip detectors and the procedure for achievement of 5 μm detector alignment. The construction of the beryllium barrel structure, which houses the detector assemblies, is also described. In addition, the 10 μm placement accuracy of the detectors in the barrel structure is discussed and the detector cooling and mounting systems are described. 12 refs

  17. The ATLAS Inner Detector commissioning and calibration

    NARCIS (Netherlands)

    Aad, G.; et al., [Unknown; Bentvelsen, S.; Colijn, A.P.; de Jong, P.; Doxiadis, A.; Garitaonandia, H.; Gosselink, M.; Kayl, M.S.; Koffeman, E.; Lee, H.; Mechnich, J.; Mussche, I.; Ottersbach, J.P.; Rijpstra, M.; Ruckstuhl, N.; Tsiakiris, M.; van der Kraaij, E.; van der Poel, E.; van Kesteren, Z.; van Vulpen, I.; Vermeulen, J.C.; Vreeswijk, M.

    2010-01-01

    The ATLAS Inner Detector is a composite tracking system consisting of silicon pixels, silicon strips and straw tubes in a 2 T magnetic field. Its installation was completed in August 2008 and the detector took part in data-taking with single LHC beams and cosmic rays. The initial detector operation,

  18. Detector normalization and scatter correction for the jPET-D4: A 4-layer depth-of-interaction PET scanner

    Energy Technology Data Exchange (ETDEWEB)

    Kitamura, Keishi [Shimadzu Corporation, 1 Nishinokyo-Kuwabaracho, Nakagyo-ku, Kyoto-shi, Kyoto 604-8511 (Japan)]. E-mail: kitam@shimadzu.co.jp; Ishikawa, Akihiro [Shimadzu Corporation, 1 Nishinokyo-Kuwabaracho, Nakagyo-ku, Kyoto-shi, Kyoto 604-8511 (Japan); Mizuta, Tetsuro [Shimadzu Corporation, 1 Nishinokyo-Kuwabaracho, Nakagyo-ku, Kyoto-shi, Kyoto 604-8511 (Japan); Yamaya, Taiga [National Institute of Radiological Sciences, 9-1 Anagawa-4, Inage-ku, Chiba-shi, Chiba 263-8555 (Japan); Yoshida, Eiji [National Institute of Radiological Sciences, 9-1 Anagawa-4, Inage-ku, Chiba-shi, Chiba 263-8555 (Japan); Murayama, Hideo [National Institute of Radiological Sciences, 9-1 Anagawa-4, Inage-ku, Chiba-shi, Chiba 263-8555 (Japan)

    2007-02-01

    The jPET-D4 is a brain positron emission tomography (PET) scanner composed of 4-layer depth-of-interaction (DOI) detectors with a large number of GSO crystals, which achieves both high spatial resolution and high scanner sensitivity. Since the sensitivity of each crystal element is highly dependent on DOI layer depth and incidental {gamma} ray energy, it is difficult to estimate normalization factors and scatter components with high statistical accuracy. In this work, we implemented a hybrid scatter correction method combined with component-based normalization, which estimates scatter components with a dual energy acquisition using a convolution subtraction-method for an estimation of trues from an upper energy window. In order to reduce statistical noise in sinograms, the implemented scheme uses the DOI compression (DOIC) method, that combines deep pairs of DOI layers into the nearest shallow pairs of DOI layers with natural detector samplings. Since the compressed data preserve the block detector configuration, as if the data are acquired using 'virtual' detectors with high {gamma}-ray stopping power, these correction methods can be applied directly to DOIC sinograms. The proposed method provides high-quality corrected images with low statistical noise, even for a multi-layer DOI-PET.

  19. A compact high resolution flat panel PET detector based on the new 4-side buttable MPPC for biomedical applications.

    Science.gov (United States)

    Wang, Qiang; Wen, Jie; Ravindranath, Bosky; O'Sullivan, Andrew W; Catherall, David; Li, Ke; Wei, Shouyi; Komarov, Sergey; Tai, Yuan-Chuan

    2015-09-11

    Compact high-resolution panel detectors using virtual pinhole (VP) PET geometry can be inserted into existing clinical or pre-clinical PET systems to improve regional spatial resolution and sensitivity. Here we describe a compact panel PET detector built using the new Though Silicon Via (TSV) multi-pixel photon counters (MPPC) detector. This insert provides high spatial resolution and good timing performance for multiple bio-medical applications. Because the TSV MPPC design eliminates wire bonding and has a package dimension which is very close to the MPPC's active area, it is 4-side buttable. The custom designed MPPC array (based on Hamamatsu S12641-PA-50(x)) used in the prototype is composed of 4 × 4 TSV-MPPC cells with a 4.46 mm pitch in both directions. The detector module has 16 × 16 lutetium yttrium oxyorthosilicate (LYSO) crystal array, with each crystal measuring 0.92 × 0.92 × 3 mm 3 with 1.0 mm pitch. The outer diameter of the detector block is 16.8 × 16.8 mm 2 . Thirty-two such blocks will be arranged in a 4 × 8 array with 1 mm gaps to form a panel detector with detection area around 7 cm × 14 cm in the full-size detector. The flood histogram acquired with Ge-68 source showed excellent crystal separation capability with all 256 crystals clearly resolved. The detector module's mean, standard deviation, minimum (best) and maximum (worst) energy resolution were 10.19%, +/-0.68%, 8.36% and 13.45% FWHM, respectively. The measured coincidence time resolution between the block detector and a fast reference detector (around 200 ps single photon timing resolution) was 0.95 ns. When tested with Siemens Cardinal electronics the performance of the detector blocks remain consistent. These results demonstrate that the TSV-MPPC is a promising photon sensor for use in a flat panel PET insert composed of many high resolution compact detector modules.

  20. Research and development of a helium-4 based solar neutrino detector

    International Nuclear Information System (INIS)

    Lanou, R.E.; Maris, H.J.; Seidel, G.M.

    1993-05-01

    Superfluid helium possesses unique properties that enable it to be used as the major component of a very sensitive calorimetric detector: it is extremely pure, and the energy deposited in it is carried out by elementary excitations of the liquid which can produce quantum evaporation of He atoms at a free surface. It has a major advantage of being able to achieve very low background levels. Experimental results presented on the development of helium-4 detector include sensitivity, heat capacity of wafer-calorimeters, coincidence measurements, spectrum of alpha particles in helium, and quantum evaporation: angular dependence and efficiency. 29 refs., 16 figs., 1 tab

  1. HgCdTe e-avalanche photodiode detector arrays

    Directory of Open Access Journals (Sweden)

    Anand Singh

    2015-08-01

    Full Text Available Initial results on the MWIR e-APD detector arrays with 30 μm pitch fabricated on LPE grown compositionally graded p-HgCdTe epilayers are presented. High dynamic resistance times active area (R0A product 2 × 106 Ω-cm2, low dark current density 4 nA/cm2 and high gain 5500 at -8 V were achieved in the n+-υ-p+ HgCdTe e-APD at 80 K. LPE based HgCdTe e-APD development makes this technology amenable for adoption in the foundries established for the conventional HgCdTe photovoltaic detector arrays without any additional investment.

  2. Visual hydrogen detector with variable reversibility

    Science.gov (United States)

    Muradov, Nazim (Inventor)

    2011-01-01

    Methods, processes and compositions are provided for a visual or chemochromic hydrogen-detector with variable or tunable reversible color change. The working temperature range for the hydrogen detector is from minus 100.degree. C. to plus 500.degree. C. A hydrogen-sensitive pigment, including, but not limited to, oxides, hydroxides and polyoxo-compounds of tungsten, molybdenum, vanadium, chromium and combinations thereof, is combined with nano-sized metal activator particles and preferably, coated on a porous or woven substrate. In the presence of hydrogen, the composition rapidly changes its color from white or light-gray or light-tan to dark gray, navy-blue or black depending on the exposure time and hydrogen concentration in the medium. After hydrogen exposure ceases, the original color of the hydrogen-sensitive pigment is restored, and the visual hydrogen detector can be used repeatedly. By changing the composition of the hydrogen-sensitive pigment, the time required for its complete regeneration is varied from a few seconds to several days.

  3. Visual hydrogen detector with variable reversibilty

    Science.gov (United States)

    Muradov, Nazim Z. (Inventor)

    2012-01-01

    Methods, processes and compositions are provided for a visual or chemochromic hydrogen-detector with variable or tunable reversible color change. The working temperature range for the hydrogen detector is from minus 100.degree. C. to plus 500.degree. C. A hydrogen-sensitive pigment, including, but not limited to, oxides, hydroxides and polyoxo-compounds of tungsten, molybdenum, vanadium, chromium and combinations thereof, is combined with nano-sized metal activator particles and preferably, coated on a porous or woven substrate. In the presence of hydrogen, the composition rapidly changes its color from white or light-gray or light-tan to dark gray, navy-blue or black depending on the exposure time and hydrogen concentration in the medium. After hydrogen exposure ceases, the original color of the hydrogen-sensitive pigment is restored, and the visual hydrogen detector can be used repeatedly. By changing the composition of the hydrogen-sensitive pigment, the time required for its complete regeneration is varied from a few seconds to several days.

  4. A supra-thermal energetic particle detector /STEP/ for composition measurements in the range of about 20 keV/nucleon to 1 MeV/nucleon

    Science.gov (United States)

    Mason, G. M.; Gloeckler, G.

    1981-01-01

    A novel detector system is described, employing a time-of-flight versus residual energy technique which allows measurement of particle composition (H-Fe), energy spectra and anisotropies in an energy range unaccessible with previously flown sensors. Applications of this method to measurements of the solar wind ion composition are also discussed.

  5. Scintillation detectors based on poly-2,4-dimethylstyrene: Structure peculiarities and radiation damage

    International Nuclear Information System (INIS)

    Gunder, O.A.; Voronkina, N.I.; Kopina, I.V.

    1995-01-01

    Scintillation detectors based on poly-2,4-dimethyl styrene (P-2,4-DMS) are studied. Investigated is the influence of two methyl groups present in the benzene ring on the energy, spectral and structural characteristics of the polymer. The said factors are assumed to result in the detectors high light output and radiation resistance. It is shown that under radiolysis (77 K) the radiation yield of the paramagnetic centers of P-2,4-DMS exceeds that of polystyrene (PST) by ∼ 1.5. Unlike PST film, the luminescence spectra of P-2,4-DMS are characterized by the presence of both excimer (320-340 nm) and monomer (292 nm) bands. Revealed are the distinction in the nature of the optical characteristics of macroradicals and the efficiency of energy transfer in gamma-irradiated PST and P-2,4-DMS scintillators. The relation between the super-molecular structure of the polymers and the interaction of their macroradicals with molecular O 2 is stated

  6. Designing a new type of neutron detector for neutron and gamma-ray discrimination via GEANT4

    International Nuclear Information System (INIS)

    Shan, Qing; Chu, Shengnan; Ling, Yongsheng; Cai, Pingkun; Jia, Wenbao

    2016-01-01

    Design of a new type of neutron detector, consisting of a fast neutron converter, plastic scintillator, and Cherenkov detector, to discriminate 14-MeV fast neutrons and gamma rays in a pulsed n–γ mixed field and monitor their neutron fluxes is reported in this study. Both neutrons and gamma rays can produce fluorescence in the scintillator when they are incident on the detector. However, only the secondary charged particles of the gamma rays can produce Cherenkov light in the Cherenkov detector. The neutron and gamma-ray fluxes can be calculated by measuring the fluorescence and Cherenkov light. The GEANT4 Monte Carlo simulation toolkit is used to simulate the whole process occurring in the detector, whose optimum parameters are known. Analysis of the simulation results leads to a calculation method of neutron flux. This method is verified by calculating the neutron fluxes using pulsed n–γ mixed fields with different n/γ ratios, and the results show that the relative errors of all calculations are <5%. - Highlights: • A neutron detector is developed to discriminate 14-MeV fast neutrons and gamma rays. • The GEANT4 is used to optimize the parameters of the detector. • A calculation method of neutron flux is established through the simulation. • Several n/γ mixture fields are simulated to validate of the calculation method.

  7. Flux distribution by neutrons semi-conductors detectors during the startup of the EL4 reactor

    International Nuclear Information System (INIS)

    Fuster, S.; Tarabella, A.

    1967-01-01

    The Cea developed neutron semi-conductors detectors which allows a quasi-instantaneous monitoring of neutrons flux distribution, when placed in a reactor during the tests. These detectors have been experimented in the EL4 reactor. The experiment and the results are presented and compared with reference mappings. (A.L.B.)

  8. Ultra-light and stable composite structure to support and cool the ATLAS pixel detector barrel electronics modules

    International Nuclear Information System (INIS)

    Olcese, M.; Caso, C.; Castiglioni, G.; Cereseto, R.; Cuneo, S.; Dameri, M.; Gemme, C.; Glitza, K.-W.; Lenzen, G.; Mora, F.; Netchaeva, P.; Ockenfels, W.; Piano, E.; Pizzorno, C.; Puppo, R.; Rebora, A.; Rossi, L.; Thadome, J.; Vernocchi, F.; Vigeolas, E.; Vinci, A.

    2004-01-01

    The design of an ultra light structure, the so-called 'stave', to support and cool the sensitive elements of the Barrel Pixel detector, the innermost part of the ATLAS detector to be installed on the new Large Hadron Collider at CERN (Geneva), is presented. Very high-dimensional stability, minimization of the material and ability of operating 10 years in a high radiation environment are the key design requirements. The proposed solution consists of a combination of different carbon-based materials (impregnated carbon-carbon, ultra high modulus carbon fibre composites) coupled to a thin aluminum tube to form a very light support with an integrated cooling channel. Our design has proven to successfully fulfil the requirements. The extensive prototyping and testing program to fully qualify the design and release the production are discussed

  9. Nuclear radiation detector based on ion implanted p-n junction in 4H-SiC

    International Nuclear Information System (INIS)

    Vervisch, V.; Issa, F.; Ottaviani, L.; Lazar, M.; Kuznetsov, A.; Szalkai, D.; Klix, A.; Lyoussi, A.; Vermeeren, L.; Hallen, A.

    2013-06-01

    In this paper, we propose a new device detector based on ion implanted p-n junction in 4H-SiC for nuclear instrumentation. We showed the interest to use 10 Boron as a Neutron Converter Layer in order to detect thermal neutrons. We present the main results obtained during irradiation tests performed in the Belgian Reactor 1. We show the capability of our detector by means of first results of the detector response at different reverse voltage biases and at different reactor power (authors)

  10. Instrumentation for characterizing materials and composed semiconductors for ionizing radiation detectors

    International Nuclear Information System (INIS)

    Paschoal, Arquimedes J.A.; Leite, Adolfo M.B.; Nazzre, Fabio V.B.; Santos, Luiz A.P.

    2007-01-01

    The purpose of this work is the development of instrumentation for characterizing some type of ionizing radiation detectors. Those detectors are being manufactured by the Nuclear Instrumentation Laboratory at CRCN/Recife and can be used both on photon beam and with particles. Such detectors consist of semiconductor material in the form of films generated by oxide growing or by means of semiconductor material deposition in a substrate. Those materials can be made of metals, semi-metals, composites or semiconductor polymers. Prior to expose those detectors to ionizing radiation, it must be physically and electrically characterized. In this intention it was developed an electromechanical system. An electrical circuit was built to measure the signal from the detector and another circuit to control the movement of four probes (4-points technique) by using a stepper motor and the micro stepping technique avoiding damage to the detector. This system can be of interest to researchers that work with a sort of semiconductor materials in the form of thin film and in nanotechnological processes aiming the design of radiation ionizing detectors. (author)

  11. Whole body dual X-ray absorptiometry for bone mineral density and body composition using a flat panel detector

    International Nuclear Information System (INIS)

    Dinten, J.M.; Robert-Coutant, C.; Gonon, G.; Bordy, T.

    2003-01-01

    Whole-body dual-energy X-ray absorptiometry (DXA) systems are used for the determination of bone mineral density (BMD) but also for body composition estimates (lean mass and fat mass). The calculation is based on the difference in attenuation of body tissues for a low-energy of about 50 KeV and a high-energy of about 80-100 KeV. The measurement of dual-energy projections allows first to compute to the body composition in the non-bone area, and then to extrapolate the fat / lean ratio of soft tissue into the bone area in order to compute the BMD. Since detectors have limited area, a whole body examination requires a scan of the patient and a reconstruction process in order to build up a large field image from smaller radiographs. This reconstruction process must keep the quantitative value of the radiographs, and avoid any distortion which could be a consequence of the conic acquisition geometry. The cone angle is low (6 at maximum) and the large overlap between radiographs helps to reconstruct an image equivalent with a parallel-beam geometry. Scatter is corrected from the radiographs before reconstruction, as described in a previous paper ('Dual-energy X-rays absorptiometry using a 2D digital radiography detector. Application to bone densitometry', SPIE Medical Imaging 2001, Medical Physics). We have developed an original reconstruction method dedicated to whole-body examinations which will be described. Thanks to the quasi-radiologic quality of the detector, reconstructed images are of very good quality and this makes the measurement of BMD and fat / lean masses easier. (author)

  12. Use of SRIM and Garfield with Geant4 for the characterization of a hybrid 10B/3He neutron detector

    Science.gov (United States)

    van der Ende, B. M.; Rand, E. T.; Erlandson, A.; Li, L.

    2018-06-01

    This paper describes a method for more complete neutron detector characterization using Geant4's Monte Carlo methods for characterizing overall detector response rate and Garfield interfaced with SRIM for the simulation of the detector's raw pulses, as applied to a hybrid 10B/3He detector. The Geant4 models characterizing the detector's interaction with a 252Cf point source and parallel beams of mono-energetic neutrons (assuming ISO 8529 reference energy values) compare and agree well with calibrated 252Cf measurements to within 6.4%. Validated Geant4 model outputs serve as input to Garfield+SRIM calculations to provide meaningful pulse height spectra. Modifications to Garfield for this work were necessary to account for simultaneous tracking of electrons resulting from proton and triton reaction products from a single 3He neutron capture event, and it was further necessary to interface Garfield with the energy loss, range, and straggling calculations provided by SRIM. Individual raw pulses generated by Garfield+SRIM are also observed to agree well with experimentally measured raw pulses from the detector.

  13. The plastic ball spectrometer - an electronic 4π detector with particle identification

    International Nuclear Information System (INIS)

    Baden, A.; Poskanzer, A.M.; Renner, T.; Riedesel, H.

    1982-04-01

    For the high multiplicity events occuring in relativistic nuclear collisions an electronic 4π detector with particle identification has been built. It consists of 815 ΔE-E telescopes and 176 TOF telescopes covering 97% of 4π. Very good particle identification has been obtained for hydrogen and helium isotopes and also π + have been detected with high efficiency. (orig.)

  14. Development of high efficiency neutron detectors

    International Nuclear Information System (INIS)

    Pickrell, M.M.; Menlove, H.O.

    1993-01-01

    The authors have designed a novel neutron detector system using conventional 3 He detector tubes and composites of polyethylene and graphite. At this time the design consists entirely of MCNP simulations of different detector configurations and materials. These detectors are applicable to low-level passive and active neutron assay systems such as the passive add-a-source and the 252 Cf shuffler. Monte Carlo simulations of these neutron detector designs achieved efficiencies of over 35% for assay chambers that can accommodate 55-gal. drums. Only slight increases in the number of detector tubes and helium pressure are required. The detectors also have reduced die-away times. Potential applications are coincident and multiplicity neutron counting for waste disposal and safeguards. The authors will present the general design philosophy, underlying physics, calculation mechanics, and results

  15. The international linear collider. Technical design report. Vol. 4. Detectors

    Energy Technology Data Exchange (ETDEWEB)

    Behnke, Ties; Brau, James E.; Burrows, Philip; Fuster, Juan; Peskin, Michael; Stanitzki, Marcel; Sugimoto, Yasuhiro; Yamada, Sakue; Yamamoto, Hitoshi [eds.

    2013-10-01

    The following topics are dealt with: The Si Vertex detectors, the main tracker, calorimetry, muon detectors, the superconducting spectrometer magnet, the detector electronics and data acquisition, simulation and reconstruction, benchmarking, costs. (HSI)

  16. The international linear collider. Technical design report. Vol. 4. Detectors

    International Nuclear Information System (INIS)

    Behnke, Ties; Brau, James E.; Burrows, Philip; Fuster, Juan; Peskin, Michael; Stanitzki, Marcel; Sugimoto, Yasuhiro; Yamada, Sakue; Yamamoto, Hitoshi

    2013-01-01

    The following topics are dealt with: The Si Vertex detectors, the main tracker, calorimetry, muon detectors, the superconducting spectrometer magnet, the detector electronics and data acquisition, simulation and reconstruction, benchmarking, costs. (HSI)

  17. GEANT4 simulation study of a gamma-ray detector for neutron resonance densitometry

    International Nuclear Information System (INIS)

    Tsuchiya, Harufumi; Harada, Hideo; Koizumi, Mitsuo; Kitatani, Fumito; Takamine, Jun; Kureta, Masatoshi; Iimura, Hideki

    2013-01-01

    A design study of a gamma-ray detector for neutron resonance densitometry was made with GEANT4. The neutron resonance densitometry, combining neutron resonance transmission analysis and neutron resonance capture analysis, is a non-destructive technique to measure amounts of nuclear materials in melted fuels of the Fukushima Daiichi nuclear power plants. In order to effectively quantify impurities in the melted fuels via prompt gamma-ray measurements, a gamma-ray detector for the neutron resonance densitometry consists of cylindrical and well type LaBr 3 scintillators. The present simulation showed that the proposed gamma-ray detector suffices to clearly detect the gamma rays emitted by 10 B(n, αγ) reaction in a high environmental background due to 137 Cs radioactivity with its Compton edge suppressed at a considerably small level. (author)

  18. Application of thermodynamics to silicate crystalline solutions

    Science.gov (United States)

    Saxena, S. K.

    1972-01-01

    A review of thermodynamic relations is presented, describing Guggenheim's regular solution models, the simple mixture, the zeroth approximation, and the quasi-chemical model. The possibilities of retrieving useful thermodynamic quantities from phase equilibrium studies are discussed. Such quantities include the activity-composition relations and the free energy of mixing in crystalline solutions. Theory and results of the study of partitioning of elements in coexisting minerals are briefly reviewed. A thermodynamic study of the intercrystalline and intracrystalline ion exchange relations gives useful information on the thermodynamic behavior of the crystalline solutions involved. Such information is necessary for the solution of most petrogenic problems and for geothermometry. Thermodynamic quantities for tungstates (CaWO4-SrWO4) are calculated.

  19. Simulation and Digitization of a Gas Electron Multiplier Detector Using Geant4 and an Object-Oriented Digitization Program

    Science.gov (United States)

    McMullen, Timothy; Liyanage, Nilanga; Xiong, Weizhi; Zhao, Zhiwen

    2017-01-01

    Our research has focused on simulating the response of a Gas Electron Multiplier (GEM) detector using computational methods. GEM detectors provide a cost effective solution for radiation detection in high rate environments. A detailed simulation of GEM detector response to radiation is essential for the successful adaption of these detectors to different applications. Using Geant4 Monte Carlo (GEMC), a wrapper around Geant4 which has been successfully used to simulate the Solenoidal Large Intensity Device (SoLID) at Jefferson Lab, we are developing a simulation of a GEM chamber similar to the detectors currently used in our lab. We are also refining an object-oriented digitization program, which translates energy deposition information from GEMC into electronic readout which resembles the readout from our physical detectors. We have run the simulation with beta particles produced by the simulated decay of a 90Sr source, as well as with a simulated bremsstrahlung spectrum. Comparing the simulation data with real GEM data taken under similar conditions is used to refine the simulation parameters. Comparisons between results from the simulations and results from detector tests will be presented.

  20. First results with the 4π charged particle detector INDRA at GANIL

    International Nuclear Information System (INIS)

    Dayras, R.

    1995-01-01

    After a three year construction period, the 4π charged particle detector INDRA took its first data at GANIL, during the spring of 1993. After a brief description of the detector characteristics, an overview of the ongoing scientific program is given. The general trend of the data are discussed. For the first time, the energy threshold for the full vaporization of a nuclear system into neutrons and Z=1 and 2 isotopes has been determined for the 36 Ar + 58 Ni reaction. For this system, this threshold is observed for an incident energy of about 50 A.MeV. (author). 18 refs., 6 figs

  1. Compound Semiconductor Radiation Detector

    International Nuclear Information System (INIS)

    Kim, Y. K.; Park, S. H.; Lee, W. G.; Ha, J. H.

    2005-01-01

    In 1945, Van Heerden measured α, β and γ radiations with the cooled AgCl crystal. It was the first radiation measurement using the compound semiconductor detector. Since then the compound semiconductor has been extensively studied as radiation detector. Generally the radiation detector can be divided into the gas detector, the scintillator and the semiconductor detector. The semiconductor detector has good points comparing to other radiation detectors. Since the density of the semiconductor detector is higher than that of the gas detector, the semiconductor detector can be made with the compact size to measure the high energy radiation. In the scintillator, the radiation is measured with the two-step process. That is, the radiation is converted into the photons, which are changed into electrons by a photo-detector, inside the scintillator. However in the semiconductor radiation detector, the radiation is measured only with the one-step process. The electron-hole pairs are generated from the radiation interaction inside the semiconductor detector, and these electrons and charged ions are directly collected to get the signal. The energy resolution of the semiconductor detector is generally better than that of the scintillator. At present, the commonly used semiconductors as the radiation detector are Si and Ge. However, these semiconductor detectors have weak points. That is, one needs thick material to measure the high energy radiation because of the relatively low atomic number of the composite material. In Ge case, the dark current of the detector is large at room temperature because of the small band-gap energy. Recently the compound semiconductor detectors have been extensively studied to overcome these problems. In this paper, we will briefly summarize the recent research topics about the compound semiconductor detector. We will introduce the research activities of our group, too

  2. Life-finding detector development at NASA GSFC using a custom H4RG test bed

    Science.gov (United States)

    Mosby, Gregory; Rauscher, Bernard; Kutyrev, Alexander

    2018-01-01

    Chemical species associated with life, called biosignatures, should be visible in exoplanet atmospheres with larger space telescopes. These signals will be faint and require very low noise (~e-) detectors to robustly measure. At NASA Goddard we are developing a single detector H4RG test bed to characterize and identify potential technology developments needed for the next generation's large space telescopes. The vacuum and cryogenic test bed will include near infrared light sources from integrating spheres using a motorized shutter. The detector control and readout will be handled by a Leach controller. Detector cables have been manufactured and test planning has begun. Planned tests include testing minimum read noise capabilities, persistence mitigation strategies using long wavelength light, and measuring intrapixel variation which might affect science goals of future missions. In addition to providing a means to identify areas of improvement in detector technology, we hope to use this test bed to probe some fundamental physics of these infrared arrays.

  3. NaI(Tl) detectors modeling in MCNP-X and Gate/Geant4 codes

    Energy Technology Data Exchange (ETDEWEB)

    Affonso, Renato Raoni Werneck; Silva, Ademir Xavier da, E-mail: raoniwa@yahoo.com.br, E-mail: ademir@nuclear.ufrj.br [Coordenacao de Pos-Graduacao e Pesquisa de Engenharia (PEN/COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Nuclear; Salgado, Cesar Marques, E-mail: otero@ien.gov.br [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2017-07-01

    NaI (Tl) detectors are widely used in gamma-ray densitometry, but their modeling in Monte Carlo codes, such as MCNP-X and Gate/Geant4, needs a lot of work and does not yield comparable results with experimental arrangements, possibly due to non-simulated physical phenomena, such as light transport within the scintillator. Therefore, it is necessary a methodology that positively impacts the results of the simulations while maintaining the real dimensions of the detectors and other objects to allow validating a modeling that matches up with the experimental arrangement. Thus, the objective of this paper is to present the studies conducted with the MCNPX and Gate/Geant4 codes, in which the comparisons of their results were satisfactory, showing that both can be used for the same purposes. (author)

  4. Characterization of B4C-composite-reinforced aluminum alloy composites

    Science.gov (United States)

    Singh, Ram; Rai, R. N.

    2018-04-01

    Dry sliding wear tests conducted on Pin-on-disk wear test machine. The rotational speed of disc is ranging from (400-600rpm) and under loads ranging from (30-70 N) the contact time between the disc and pin is constant for each pin specimen of composites is 15 minute. In all manufacturing industries the uses of composite materials has been increasing globally, In the present study, an aluminum 5083 alloy is used as the matrix and 5% of weight percentage of Boron Carbide (B4C) as the reinforcing material. The composite is produced using stir casting technique. This is cost effective method. The aluminum 5083 matrix can be strengthened by reinforcing with hard ceramic particles like silicon carbide and boron carbide. In this experiment, aluminum 5083 alloy is selected as one of main material for making parts of the ship it has good mechanical properties, good corrosion resistance and it is can welded very easily and does have good strength. The samples are tested for hardness and tensile strength. The mechanical properties like Hardness can be increased by reinforcing aluminum 5083alloy 5% boron carbide (B4C) particles and tensile strength. Finally the Scanning Electron Microscope (SEM) analysis and EDS is done, which helps to study topography of composites and it produces images of a sample by scanning it with a focused beam of electrons and the presence of composition found in the matrix.

  5. The ALICE forward multiplicity detector

    DEFF Research Database (Denmark)

    Holm Christensen, Christian; Gulbrandsen, Kristjan; Sogaard, Carsten

    2007-01-01

    The ALICE Forward Multiplicity Detector (FMD) is a silicon strip detector with 51,200 strips arranged in 5 rings, covering the range $-3.4......The ALICE Forward Multiplicity Detector (FMD) is a silicon strip detector with 51,200 strips arranged in 5 rings, covering the range $-3.4...

  6. Activation method for measuring the reaction rates and studying the neutron spectra parameters, based on using the unified composition detectors

    International Nuclear Information System (INIS)

    Demidov, A.M.; Dikarev, V.S.; Efimov, B.V.; Ionov, V.S.; Marin, S.V.

    2005-01-01

    The method proposed for estimation of parameters thermal and epithermal parts of energy distribution of neutrons is described. The method based on application of activation measuring with use of unified composition detectors (UCD) and samples of fuel. The method is applicable for definition of neutron spectrum parameters and velocities of division in fuel of nuclear installations. Theoretical bases and the description of a method, expedients of manufacturing and calibration for the detectors, the experimental data, carried out in RRC KI are given and processing of experimental data, and also. The parametric model of a spectrum constructed on the basis of Westcott's formalism is described. The parameter of stiffness is entered and its role for temperature of neutron gas, spectral coefficients of isotopes of detectors, the transition area thermal and epithermal parts of neutron spectra is observationally appreciated. It is offered to confirm the found results by calculations with use of MCU Monte Carlo code [ru

  7. Semiconductor radiation detectors technology and applications

    CERN Document Server

    2018-01-01

    The aim of this book is to educate the reader on radiation detectors, from sensor to read-out electronics to application. Relatively new detector materials, such as CdZTe and Cr compensated GaAs, are introduced, along with emerging applications of radiation detectors. This X-ray technology has practical applications in medical, industrial, and security applications. It identifies materials based on their molecular composition, not densities as the traditional transmission equipment does. With chapters written by an international selection of authors from both academia and industry, the book covers a wide range of topics on radiation detectors, which will satisfy the needs of both beginners and experts in the field.

  8. Surface-Anchored Poly(4-vinylpyridine)–Single-Walled Carbon Nanotube–Metal Composites for Gas Detection

    KAUST Repository

    Yoon, Bora

    2016-08-05

    A platform for chemiresistive gas detectors based upon single-walled carbon nanotube (SWCNT) dispersions stabilized by poly(4-vinylpyridine) (P4VP) covalently immobilized onto a glass substrate was developed. To fabricate these devices, a glass substrate with gold electrodes is treated with 3-bromopropyltrichlorosilane. The resulting alkyl bromide coating presents groups that can react with the P4VP to covalently bond (anchor) the polymer–SWCNT composite to the substrate. Residual pyridyl groups in P4VP not consumed in this quaternization reaction are available to coordinate metal nanoparticles or ions chosen to confer selectivity and sensitivity to target gas analytes. Generation of P4VP coordinated to silver nanoparticles produces an enhanced response to ammonia gas. The incorporation of soft Lewis acidic Pd2+ cations by binding PdCl2 to P4VP yields a selective and highly sensitive device that changes resistance upon exposure to vapors of thioethers. The latter materials have utility for odorized fuel leak detection, microbial activity, and breath diagnostics. A third demonstration makes use of permanganate incorporation to produce devices with large responses to vapors of volatile organic compounds that are susceptible to oxidation.

  9. Units of signals in the surface and underground scintillation detectors of the Yakutsk array

    International Nuclear Information System (INIS)

    Dedenko, L G; Fedorova, G F; Roganova, T M

    2013-01-01

    Signals in the surface and underground scintillation detectors from the extensive air shower particles at the Yakutsk array are measured in some practical units. These units are signals in detectors caused by the near vertical muons. These signals from the near vertical muons in the surface and underground detectors have been simulated with the help of the GEANT4 package. These simulations follow up the real experimental calibration of the surface and underground detectors carried out at the Yakutsk array. Results of simulations show the noticeable difference of ∼5% in energies deposited in these two types of detectors. This difference should be taken into account to interpret correctly data on the fraction of muons observed at the Yakutsk array and to make real conclusions about the composition of the primary cosmic radiation at ultra-high energies.

  10. Composites in small and simple devices to increase mixing on detector surfaces

    Science.gov (United States)

    Hernandez, L. F.; Lima, R. R.; Leite, A. R.; Fachini, E. R.; Silva, M. L. P.

    2013-03-01

    This work aims at three different applications for the betterment of plasma generated-composite thin films: pre-mixing, spray formation in miniaturized structures and an increase in the performance of detector surfaces. Miniaturized structures were projected, simulated with FEMLAB® 3.2 software and then constructed. Clustered films made from tetraethoxysilane (TEOS) and nonafluoro(iso)butyl ether (HFE®) precursors were deposited on silicon, acrylic and quartz substrates for different kinds of film characterization/or in the projected structures. Physical and chemical characterization guided the selection of best films previous to/after UVC exposure. The active surfaces (plasma-deposited films) in structures were modified by UVC exposure and then tested. The applications include pre-mixing of liquids and/or spray formation, best results being obtained with surface covered by derivative-HFE films, which acted as passivation layers. Preliminary results show good humidity sensing for TEOS-derivative films.

  11. Composites in small and simple devices to increase mixing on detector surfaces

    International Nuclear Information System (INIS)

    Hernandez, L F; Lima, R R; Leite, A R; Silva, M L P; Fachini, E R

    2013-01-01

    This work aims at three different applications for the betterment of plasma generated-composite thin films: pre-mixing, spray formation in miniaturized structures and an increase in the performance of detector surfaces. Miniaturized structures were projected, simulated with FEMLAB ® 3.2 software and then constructed. Clustered films made from tetraethoxysilane (TEOS) and nonafluoro(iso)butyl ether (HFE ® ) precursors were deposited on silicon, acrylic and quartz substrates for different kinds of film characterization/or in the projected structures. Physical and chemical characterization guided the selection of best films previous to/after UVC exposure. The active surfaces (plasma-deposited films) in structures were modified by UVC exposure and then tested. The applications include pre-mixing of liquids and/or spray formation, best results being obtained with surface covered by derivative-HFE films, which acted as passivation layers. Preliminary results show good humidity sensing for TEOS-derivative films.

  12. Detector Simulation: Data Treatment and Analysis Methods

    CERN Document Server

    Apostolakis, J

    2011-01-01

    Detector Simulation in 'Data Treatment and Analysis Methods', part of 'Landolt-Börnstein - Group I Elementary Particles, Nuclei and Atoms: Numerical Data and Functional Relationships in Science and Technology, Volume 21B1: Detectors for Particles and Radiation. Part 1: Principles and Methods'. This document is part of Part 1 'Principles and Methods' of Subvolume B 'Detectors for Particles and Radiation' of Volume 21 'Elementary Particles' of Landolt-Börnstein - Group I 'Elementary Particles, Nuclei and Atoms'. It contains the Section '4.1 Detector Simulation' of Chapter '4 Data Treatment and Analysis Methods' with the content: 4.1 Detector Simulation 4.1.1 Overview of simulation 4.1.1.1 Uses of detector simulation 4.1.2 Stages and types of simulation 4.1.2.1 Tools for event generation and detector simulation 4.1.2.2 Level of simulation and computation time 4.1.2.3 Radiation effects and background studies 4.1.3 Components of detector simulation 4.1.3.1 Geometry modeling 4.1.3.2 External fields 4.1.3.3 Intro...

  13. Preparation, characterization and enhanced visible-light photocatalytic activities of BiPO4/BiVO4 composites

    International Nuclear Information System (INIS)

    Wu, Siyuan; Zheng, Hong; Lian, Youwei; Wu, Yiying

    2013-01-01

    Graphical abstract: - Highlights: • BiPO 4 /BiVO 4 composites were successfully prepared by the hydrothermal method. • BiPO 4 /BiVO 4 composites exhibited broad absorption in the visible region. • Visible-light photocatalytic activities of BiPO 4 /BiVO 4 composites were enhanced. • P/V molar ratio and pH value of the reaction affect photocatalytic activity. • The mechanism of enhanced visible-light photocatalytic activities was discussed. - Abstract: BiPO 4 /BiVO 4 composites with different P/V molar ratios were prepared by the hydrothermal method and the effect of pH values of hydrothermal reaction on photocatalytic activity of BiPO 4 /BiVO 4 composite was investigated. The photocatalysts were characterized by X-ray diffraction, field emission scanning electron microscopy, energy-dispersive spectroscopy, X-ray photoelectron spectroscopy and UV–vis diffuse reflectance spectroscopy. The photocatalytic property of BiPO 4 /BiVO 4 was evaluated by photocatalytic degradation of Methylene blue under visible light irradiation. The results showed that the photocatalytic activity of the composites was much higher than that of pure BiPO 4 and BiVO 4 . The rate constant of Methylene blue degradation over BiPO 4 /BiVO 4 (P/V molar ratio of 5:1 and hydrothermal reaction pH value of 1.5) is 1.7 times that of pure BiVO 4 . The photocatalytic activity enhancement of BiPO 4 /BiVO 4 composite is closely related to the BiVO 4 functioning as a sensitizer to adsorb visible light and the heterojunction of BiPO 4 /BiVO 4 acting as an active center for hindering the rapid recombination of electron–hole pairs during the photocatalytic reaction

  14. Development of Ultra-Fast Silicon Detectors for 4D tracking

    Science.gov (United States)

    Staiano, A.; Arcidiacono, R.; Boscardin, M.; Dalla Betta, G. F.; Cartiglia, N.; Cenna, F.; Ferrero, M.; Ficorella, F.; Mandurrino, M.; Obertino, M.; Pancheri, L.; Paternoster, G.; Sola, V.

    2017-12-01

    In this contribution we review the progress towards the development of a novel type of silicon detectors suited for tracking with a picosecond timing resolution, the so called Ultra-Fast Silicon Detectors. The goal is to create a new family of particle detectors merging excellent position and timing resolution with GHz counting capabilities, very low material budget, radiation resistance, fine granularity, low power, insensitivity to magnetic field, and affordability. We aim to achieve concurrent precisions of ~ 10 ps and ~ 10 μm with a 50 μm thick sensor. Ultra-Fast Silicon Detectors are based on the concept of Low-Gain Avalanche Detectors, which are silicon detectors with an internal multiplication mechanism so that they generate a signal which is factor ~10 larger than standard silicon detectors. The basic design of UFSD consists of a thin silicon sensor with moderate internal gain and pixelated electrodes coupled to full custom VLSI chip. An overview of test beam data on time resolution and the impact on this measurement of radiation doses at the level of those expected at HL-LHC is presented. First I-V and C-V measurements on a new FBK sensor production of UFSD, 50 μm thick, with B and Ga, activated at two diffusion temperatures, with and without C co-implantation (in Low and High concentrations), and with different effective doping concentrations in the Gain layer, are shown. Perspectives on current use of UFSD in HEP experiments (UFSD detectors have been installed in the CMS-TOTEM Precision Protons Spectrometer for the forward physics tracking, and are currently taking data) and proposed applications for a MIP timing layer in the HL-LHC upgrade are briefly discussed.

  15. Virtual point detector: On the interpolation and extrapolation of scintillation detectors counting efficiencies

    International Nuclear Information System (INIS)

    Presler, Oren; German, Uzi; Pushkarsky, Vitaly; Alfassi, Zeev B.

    2006-01-01

    The concept of transforming the detector volume to a virtual point detector, in order to facilitate efficiency evaluations for different source locations, was proposed in the past for HPGe and Ge(Li) detectors. The validity of this model for NaI(Tl) and BGO scintillation detectors was studied in the present work. It was found that for both scintillation detectors, the point detector model does not seem to fit too well to the experimental data, for the whole range of source-to-detector distances; however, for source-to-detector cap distances larger than 4 cm, the accuracy was found to be high. A two-parameter polynomial expression describing the dependence of the normalized count rate versus the source-to-detector distance was fitted to the experimental data. For this fit, the maximum deviations are up to about 12%. These deviations are much smaller than the values obtained by applying the virtual point concept, even for distances greater than 4 cm, thus the polynomial fitting is to be preferred for scintillation detectors

  16. Gas Detectors Performance in CMS and Excited Muon Search Feasibility Study at 14 teV

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00572294; Mahrous, Ayman; Yasein, Mohamed Nabil

    Within the Standard Model(SM) of particle physics, quarks and leptons are understood to be the fundamental particles and Their existence have been verified experimentally. A search for substructure of quarks or study of quark compositeness is carried out with the CMS detector at LHC, using $ 300 fb^{-1} $ of integrated luminosity at a center-of-mass energy$ \\sqrt{s} =14 TeV $. The discovery of excited muons ($ \\mu^{*} $) would be a first indication of lepton compositeness. In the current study, $ \\mu^{*} $ is assumed to be produced via four-fermions contact interactions in association with a muon ($ \\mu $) and to decay via the gauge mediated process $ \\mu^{*} \\to \\mu\\gamma$, yielding a final state with two muons and a photon. Monte Carlo (MC) samples are produced via MadGraph5 and PYTHIA 8 event generators. To simulate the detector response, GEANT4 which interfaced to CMS software was used for full simulation and Delphes was used for fast simulation, assuming the CMS detector configuration. Objects and ev...

  17. Fading of CaSO4 thermoluminescent detectors after exposure to charged particles

    Czech Academy of Sciences Publication Activity Database

    Pachnerová Brabcová, Kateřina; Štěpán, Václav; Kubančák, Ján; Davídková, Marie; Ambrožová, Iva

    2017-01-01

    Roč. 106, č. 12 (2017), s. 569-572 ISSN 1350-4487 R&D Projects: GA ČR GJ15-16622Y Institutional support: RVO:61389005 Keywords : thermoluminescent detectors * CaSO4:Dy * fading * charged particles Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders OBOR OECD: Nuclear physics Impact factor: 1.442, year: 2016

  18. Characterisation of a SAGe well detector using GEANT4 and LabSOCS

    Energy Technology Data Exchange (ETDEWEB)

    Britton, R., E-mail: rich.britton@awe.co.uk [AWE, Aldermaston, Reading, Berkshire RG7 4PR (United Kingdom); University of Surrey, Guildford GU2 7XH (United Kingdom); Davies, A.V. [AWE, Aldermaston, Reading, Berkshire RG7 4PR (United Kingdom)

    2015-06-21

    This paper reports on the performance of a recently developed Small Anode Germanium (SAGe) well detector from Canberra Industries. This has been specifically designed to improve the energy resolution of the detector, such that it is comparable to the performance of broad-energy designs while achieving far higher efficiencies. Accurate efficiency characterisations and cascade summing correction factors are crucial for quantifying the radionuclides present in environmental samples, and these were calculated for the complex geometry posed by the well detector using two different methodologies. The first relied on Monte-Carlo simulations based upon the GEANT4 toolkit, and the second utilised Canberra Industries GENIE™ 2000 Gamma Analysis software in conjunction with a LabSOCS™ characterisation. Both were found to be in excellent agreement for all nuclides except for {sup 152}Eu, which presents a known issue in the Canberra software (all nuclides affected by this issue were well documented, and fixes are being developed). The correction factors were used to analyse two fully characterised reference samples, yielding results in good agreement with the accepted activity concentrations. Given the sensitivity of well type geometries to cascade summing, this represents a considerable achievement, and paves the way for the use of the SAGe well detector in analysis of ‘real-world’ environmental samples. With the efficiency increase when using the SAGe well in place of a BEGe, substantial reductions in the Minimum Detectable Activity (MDA) should be achievable for a range of nuclides.

  19. Characterisation of a SAGe well detector using GEANT4 and LabSOCS

    International Nuclear Information System (INIS)

    Britton, R.; Davies, A.V.

    2015-01-01

    This paper reports on the performance of a recently developed Small Anode Germanium (SAGe) well detector from Canberra Industries. This has been specifically designed to improve the energy resolution of the detector, such that it is comparable to the performance of broad-energy designs while achieving far higher efficiencies. Accurate efficiency characterisations and cascade summing correction factors are crucial for quantifying the radionuclides present in environmental samples, and these were calculated for the complex geometry posed by the well detector using two different methodologies. The first relied on Monte-Carlo simulations based upon the GEANT4 toolkit, and the second utilised Canberra Industries GENIE™ 2000 Gamma Analysis software in conjunction with a LabSOCS™ characterisation. Both were found to be in excellent agreement for all nuclides except for 152 Eu, which presents a known issue in the Canberra software (all nuclides affected by this issue were well documented, and fixes are being developed). The correction factors were used to analyse two fully characterised reference samples, yielding results in good agreement with the accepted activity concentrations. Given the sensitivity of well type geometries to cascade summing, this represents a considerable achievement, and paves the way for the use of the SAGe well detector in analysis of ‘real-world’ environmental samples. With the efficiency increase when using the SAGe well in place of a BEGe, substantial reductions in the Minimum Detectable Activity (MDA) should be achievable for a range of nuclides

  20. Porous nanocubic Mn3O4-Co3O4 composites and their application as electrochemical supercapacitors.

    Science.gov (United States)

    Pang, Huan; Deng, Jiawei; Du, Jimin; Li, Sujuan; Li, Juan; Ma, Yahui; Zhang, Jiangshan; Chen, Jing

    2012-09-14

    A simple approach has been developed to fabricate ideal supercapacitors based on porous Mn(3)O(4)-Co(3)O(4) nanocubic composite electrodes. We can easily obtain porous corner-truncated nanocubic Mn(3)O(4)-Co(3)O(4) composite nanomaterials without any subsequent complicated workup procedure for the removal of a hard template, seed or by using a soft template. In such a composite, the porous Mn(3)O(4)-Co(3)O(4) enables a fast and reversible redox reaction to improve the specific capacitance. The porous nanocubic Mn(3)O(4)-Co(3)O(4) composite electrode can effectively transport electrolytes and shorten the ion diffusion path, which offers excellent electrochemical performance. These results suggest that such porous Mn(3)O(4)-Co(3)O(4) composite nanocubes are very promising for next generation high-performance supercapacitors.

  1. Pulse Shape Analysis and Discrimination for Silicon-Photomultipliers in Helium-4 Gas Scintillation Neutron Detector

    Science.gov (United States)

    Barker, Cathleen; Zhu, Ting; Rolison, Lucas; Kiff, Scott; Jordan, Kelly; Enqvist, Andreas

    2018-01-01

    Using natural helium (helium-4), the Arktis 180-bar pressurized gas scintillator is capable of detecting and distinguishing fast neutrons and gammas. The detector has a unique design of three optically separated segments in which 12 silicon-photomultiplier (SiPM) pairs are positioned equilaterally across the detector to allow for them to be fully immersed in the helium-4 gas volume; consequently, no additional optical interfaces are necessary. The SiPM signals were amplified, shaped, and readout by an analog board; a 250 MHz, 14-bit digitizer was used to examine the output pulses from each SiPMpair channel. The SiPM over-voltage had to be adjusted in order to reduce pulse clipping and negative overshoot, which was observed for events with high scintillation production. Pulse shaped discrimination (PSD) was conducted by evaluating three different parameters: time over threshold (TOT), pulse amplitude, and pulse integral. In order to differentiate high and low energy events, a 30ns gate window was implemented to group pulses from two SiPM channels or more for the calculation of TOT. It was demonstrated that pulses from a single SiPM channel within the 30ns window corresponded to low-energy gamma events while groups of pulses from two-channels or more were most likely neutron events. Due to gamma pulses having lower pulse amplitude, the percentage of measured gamma also depends on the threshold value in TOT calculations. Similarly, the threshold values were varied for the optimal PSD methods of using pulse amplitude and pulse area parameters. Helium-4 detectors equipped with SiPMs are excellent for in-the-field radiation measurement of nuclear spent fuel casks. With optimized PSD methods, the goal of developing a fuel cask content monitoring and inspection system based on these helium-4 detectors will be achieved.

  2. The Fabrication and Characterization of Ni/4H-SiC Schottky Diode Radiation Detectors with a Sensitive Area of up to 4 cm².

    Science.gov (United States)

    Liu, Lin-Yue; Wang, Ling; Jin, Peng; Liu, Jin-Liang; Zhang, Xian-Peng; Chen, Liang; Zhang, Jiang-Fu; Ouyang, Xiao-Ping; Liu, Ao; Huang, Run-Hua; Bai, Song

    2017-10-13

    Silicon carbide (SiC) detectors of an Ni/4H-SiC Schottky diode structure and with sensitive areas of 1-4 cm² were fabricated using high-quality lightly doped epitaxial 4H-SiC material, and were tested in the detection of alpha particles and pulsed X-rays/UV-light. A linear energy response to alpha particles ranging from 5.157 to 5.805 MeV was obtained. The detectors were proved to have a low dark current, a good energy resolution, and a high neutron/gamma discrimination for pulsed radiation, showing the advantages in charged particle detection and neutron detection in high-temperature and high-radiation environments.

  3. Robust high temperature composite and CO sensor made from such composite

    Science.gov (United States)

    Dutta, Prabir K.; Ramasamy, Ramamoorthy; Li, Xiaogan; Akbar, Sheikh A.

    2010-04-13

    Described herein is a composite exhibiting a change in electrical resistance proportional to the concentration of a reducing gas present in a gas mixture, detector and sensor devices comprising the composite, a method for making the composite and for making devices comprising the composite, and a process for detecting and measuring a reducing gas in an atmosphere. In particular, the reducing gas may be carbon monoxide and the composite may comprise rutile-phase TiO2 particles and platinum nanoclusters. The composite, upon exposure to a gas mixture containing CO in concentrations of up to 10,000 ppm, exhibits an electrical resistance proportional to the concentration of the CO present. The composite is useful for making sensitive, low drift, fast recovering detectors and sensors, and for measuring CO concentrations in a gas mixture present at levels from sub-ppm up to 10,000 ppm. The composites, and devices made from the composites, are stable and operable in a temperature range of from about 450.degree. C. to about 700.degree. C., such as may be found in a combustion chamber.

  4. Measurements on a prototype segmented Clover detector

    CERN Document Server

    Shepherd, S L; Cullen, D M; Appelbe, D E; Simpson, J; Gerl, J; Kaspar, M; Kleinböhl, A; Peter, I; Rejmund, M; Schaffner, H; Schlegel, C; France, G D

    1999-01-01

    The performance of a segmented Clover germanium detector has been measured. The segmented Clover detector is a composite germanium detector, consisting of four individual germanium crystals in the configuration of a four-leaf Clover, housed in a single cryostat. Each crystal is electrically segmented on its outer surface into four quadrants, with separate energy read-outs from nine crystal zones. Signals are also taken from the inner contact of each crystal. This effectively produces a detector with 16 active elements. One of the purposes of this segmentation is to improve the overall spectral resolution when detecting gamma radiation emitted following a nuclear reaction, by minimising Doppler broadening caused by the opening angle subtended by each detector element. Results of the tests with sources and in beam will be presented. The improved granularity of the detector also leads to an improved isolated hit probability compared with an unsegmented Clover detector. (author)

  5. Radiation measurements by pn junction InSb detector at the temperature from 4.2 K to 115 K

    International Nuclear Information System (INIS)

    Kanno, Ikuo; Yoshihara, Fumiki; Nouchi, Ryo; Sugiura, Osamu; Murase, Yasuhiro; Nakamura, Tatsuya; Katagiri, Masaki

    2003-01-01

    We fabricated the pn junction-type detectors on a p-type InSb substrate. Both sides of the InSb substrate were etched using a mixture of nitric and lactic acids. On the top side surface, Sn and Al were deposited by heat evaporation and then the Sn was diffused into the p-type InSb by lamp annealing and resulted in the n-type layer. Based on the confirmation of the performance of the InSb detector at temperatures of 0.5 K and 4.2 K, we concentrated on the measurement of alpha particles by the pm junction-type InSb detectors at higher operating temperatures of up to 115 K. The InSb detector showed a wide temperature operating range. We can conclude that all of the voltage was induced slowly by the holes at 4.2 K and mainly as a result of electrons at 77 K. (T. Tanaka)

  6. Array of germanium detectors for nuclear safeguards

    International Nuclear Information System (INIS)

    Moss, C.E.; Bernard, W.; Dowdy, E.J.; Garcia, C.; Lucas, M.C.; Pratt, J.C.

    1983-01-01

    Our gamma-ray spectrometer system, designed for field use, offers high efficiency and high resolution for safeguards applications. The system consists of three 40% high-purity germanium detectors and a LeCroy 3500 data-acquisition system that calculates a composite spectrum for the three detectors. The LeCroy 3500 mainframe can be operated remotely from the detector array with control exercised through moderns and the telephone system. System performance with a mixed source of 125 Sb, 154 Eu, and 155 Eu confirms the expected efficiency of 120% with an overall resolution that is between the resolution of the best detector and that of the worst

  7. Realization of nuclear aggregates detector integrated into 4Π counter at S.I.S

    International Nuclear Information System (INIS)

    Tezkratt, R.

    1992-06-01

    A new cluster detector composed of ionization chambers and thin plastic scintillation, has been developed as part of the large 4 PI counter of SIS/ESR, in order to explore central collisions of high energy heavy ions. In the first part are reported the definition, description, theoretical and experimental studies and installation on site of this detector. Its expected response has been investigated with the use of GEANT simulation program. Results are presented and discussed in second part. The efficiency of the track reconstruction with plastic wall has been tested. The excitation function measurement of Au+Au system at 100, 150, 250, 400, 600 and 800 A MeV has been realized. The purpose of the last part is the presentation of the first data acquisition. The cluster gauging and the algorithm development of trajectory reconstitution between the cluster detector and plastic scintillator wall are also presented

  8. The Fabrication and Characterization of Ni/4H-SiC Schottky Diode Radiation Detectors with a Sensitive Area of up to 4 cm2

    Directory of Open Access Journals (Sweden)

    Lin-Yue Liu

    2017-10-01

    Full Text Available Silicon carbide (SiC detectors of an Ni/4H-SiC Schottky diode structure and with sensitive areas of 1–4 cm2 were fabricated using high-quality lightly doped epitaxial 4H-SiC material, and were tested in the detection of alpha particles and pulsed X-rays/UV-light. A linear energy response to alpha particles ranging from 5.157 to 5.805 MeV was obtained. The detectors were proved to have a low dark current, a good energy resolution, and a high neutron/gamma discrimination for pulsed radiation, showing the advantages in charged particle detection and neutron detection in high-temperature and high-radiation environments.

  9. Preparation and characterisation of superheated drop detectors

    International Nuclear Information System (INIS)

    Krishnamoorthy, P.

    1989-01-01

    Basic mechanism of bubble nucleation in superheated drops with respect to minimum energy of radiation and temperature is discussed. Experimental details and techniques for the preparation of Superheated Drop Detectors (SDDs) is explained. For the sample preparation, homogeneous composition of polymer (Morarfloc) and glycerine was used as the host medium and three different refrigerants Mafron-21, Mafron-12 and Mafron-11/12 (50:50) were chosen as the sensitive liquids. A pressure reactor developed at Health and Safety Laboratory is used for dispersing the sensitive liquid drops in the homogeneous composition under pressure. Some of the imporatant detector characteristics were studied. (author). 26 refs., 9 figs., 1 tab

  10. Efficient UV-emitting X-ray phosphors: octahedral Zr(PO4)6 luminescence centers in potassium hafnium-zirconium phosphates K2Hf1-xZrx(PO4)2 and KHf2(1-x)Zr2x(PO4)3

    International Nuclear Information System (INIS)

    Torardi, C.C.; Miao, C.R.; Li, J.

    2003-01-01

    Potassium hafnium-zirconium phosphates, K 2 Hf 1-x Zr x (PO 4 ) 2 and KHf 2(1-x) Zr 2x (PO 4 ) 3 , are broad-band UV-emitting phosphors. At room temperature, they have emission peak maxima at approximately 322 and 305 nm, respectively, under 30 kV peak molybdenum X-ray excitation. Both phosphors demonstrate luminescence efficiencies that make them up to ∼60% as bright as commercially available CaWO 4 Hi-Plus. The solid-state and flux synthesis conditions, and X-ray excited UV luminescence of these two phosphors are discussed. Even though the two compounds have different atomic structures, they contain zirconium in the same active luminescence environment as that found in highly efficient UV-emitting BaHf 1-x Zr x (PO 4 ) 2 . All the three materials have hafnium and zirconium in octahedral coordination via oxygen-atom corner sharing with six separate PO 4 tetrahedra. This octahedral Zr(PO 4 ) 6 moiety appears to be an important structural element for efficient X-ray excited luminescence, as are the edge-sharing octahedral TaO 6 chains for tantalate emission

  11. Pyrene As a New Detector for Determining the Composition of Silver Nanoparticle Dispersions in Aqueous Solutions

    Science.gov (United States)

    Romanovskaya, G. I.; Kazakova, S. Yu.; Koroleva, M. V.; Zuev, B. K.

    2018-03-01

    It is proposed that the fluorescence of monomeric molecules of pyrene in solid matrices or in concentrated micellar solutions be used as a detector for determining the compositional homogeneity of silver nanoparticle (NP) dispersions in aqueous solutions synthesized in different ways. It is found that the morphology of silver NPs affects the change in the fluorescence intensity of monomeric molecules of pyrene in a certain (violet or blue) region of the pyrene optical spectrum. The observed phenomenon is attributed to the resonance of electronic transitions in the monomeric molecules of pyrene in regions with plasmon oscillations in silver nanoparticles. A new way of obtaining fluorescent silver NPs is found.

  12. Detector Developments for the High Luminosity LHC Era (1/4)

    CERN Multimedia

    CERN. Geneva

    2010-01-01

    Calorimetry and Muon Spectrometers - Part I : In the first part of the lecture series, the motivation for a high luminosity upgrade of the LHC will be quickly reviewed together with the challenges for the LHC detectors. In particular, the plans and ongoing research for new calorimeter detectors will be explained. The main issues in the high-luminosity era are an improved radiation tolerance, natural ageing of detector components and challenging trigger and physics requirements. The new technological solutions for calorimetry at a high-luminosity LHC will be reviewed.

  13. Absorption phenomenon study of low energies gamma rays in the Eurogam detector STACK

    International Nuclear Information System (INIS)

    Wei, L.; Duchene, G.; Beck, F.A.; Curien, D.; France, G. de; Moszynski, M.; Santos, D.

    1991-05-01

    The composite 4 π γ detector STACK is made of a pile of Ge Crystals in which the 2 circular surfaces are active, one implanted with Boron, the other diffused with Lithium and introducing a dead zone. The goal of this study is to research the dead zones and to study their influence upon the detection efficiency [fr

  14. Neutrons and light nuclei detectors realization for the 4π multidetector amphora

    International Nuclear Information System (INIS)

    Pastor, C.

    1987-01-01

    Detection of light charged particles emitted in reactions induced by heavy ions has been studied. Several types of detectors are presented as phoswiches of scintillators, single scintillators or combinations of scintillators having different functions (either detection of charged particles only or detection of charged particles and neutrons). The AMPHORA 4 π detection array has been designed and built as a set of 140 of these cells. Il covers a solid angle of 82 % out of 4 π around a target bombarded by ion beams delivered by the SARA facility in Grenoble [fr

  15. Evaluation of the phase composition of (NH4)2SO4 + (NH4)H2PO4 mixtures by X-ray diffractometry

    International Nuclear Information System (INIS)

    Ortiz, Angel L.; Cumbrera, Francisco L.; Perez, Jose; Vas, Beatriz del; Perez, Eduardo

    2009-01-01

    The phase composition of standard (NH 4 ) 2 SO 4 + (NH 4 )H 2 PO 4 mixtures was investigated by X-ray diffractometry (XRD) using the internal-standard, reference-intensity-ratio, and Rietveld methods. It was found that the Rietveld method yields the most accurate phase-composition measurements, with an average error of ∼2 wt.%. It was also found that the internal-standard method is only effective in determining the phase composition if the calibration curve for (NH 4 )H 2 PO 4 is used, giving an average error of ∼6.5 wt.%. On the contrary, the internal-standard method with the calibration curve of the (NH 4 ) 2 SO 4 phase and the reference-intensity-ratio method are not valid. The inappropriateness of these two methods was attributed to graininess in the (NH 4 ) 2 SO 4 phase, with the attendant deviation of its diffracted intensities from the theoretical values. Direct scanning electron microscopy observations of the morphology of the powder particles in the mixtures showed clear evidence of the large agglomerates formed because the individual powder particles are partially sintered together during milling, thus corroborating the graininess determined by the XRD analyses. Finally, the implications of the present study for the quantitative phase-composition analysis of (NH 4 ) 2 SO 4 + (NH 4 )H 2 PO 4 mixtures, which are of great technological importance for the fire prevention industry, are discussed.

  16. Gamma radiation detectors for safeguards applications

    International Nuclear Information System (INIS)

    Carchon, R.; Moeslinger, M.; Bourva, L.; Bass, C.; Zendel, M.

    2007-01-01

    The IAEA uses extensively a variety of gamma radiation detectors to verify nuclear material. These detectors are part of standardized spectrometry systems: germanium detectors for High-Resolution Gamma Spectrometry (HRGS); Cadmium Zinc Telluride (CZT) detectors for Room Temperature Gamma Spectrometry (RTGS); and NaI(Tl) detectors for Low Resolution Gamma Spectrometry (LRGS). HRGS with high-purity Germanium (HpGe) detectors cooled by liquid nitrogen is widely used in nuclear safeguards to verify the isotopic composition of plutonium or uranium in non-irradiated material. Alternative cooling systems have been evaluated and electrically cooled HpGe detectors show a potential added value, especially for unattended measurements. The spectrometric performance of CZT detectors, their robustness and simplicity are key to the successful verification of irradiated materials. Further development, such as limiting the charge trapping effects in CZT to provide improved sensitivity and energy resolution are discussed. NaI(Tl) detectors have many applications-specifically in hand-held radioisotope identification devices (RID) which are used to detect the presence of radioactive material where a lower resolution is sufficient, as they benefit from a generally higher sensitivity. The Agency is also continuously involved in the review and evaluation of new and emerging technologies in the field of radiation detection such as: Peltier-cooled CdTe detectors; semiconductor detectors operating at room temperature such as HgI 2 and GaAs; and, scintillator detectors using glass fibres or LaBr 3 . A final conclusion, proposing recommendations for future action, is made

  17. Diogene: A 4π detector, based on a time projection chamber, for studying central collisions of relativistic heavy ions

    International Nuclear Information System (INIS)

    Gosset, J.

    1981-01-01

    'Diogene' is the name we have chosen for a 4π solid angle detector, based on a Time Projection Chamber, designed to perform exclusive measurements of charged particles emitted in central collisions or relativistic heavy ions. This detector is being developed by a collaboration between physicists from Saclay, Strasbourg and Clermont Ferrand, to be installed at the Saturne Synchrotron in Saclay. I first give the motivations for our choice of a TPC rather than any other kind of detector, then I recall the principle of such a detector, before describing it with more detail and describing its present status and forsean capabilities, including some discussion about the possible extension of such a detector towards higher energies and/or heavier beams. (orig.)

  18. Diogene: a 4π detector, based on a time projection chamber, for studying central collisions of relativistic heavy ions

    International Nuclear Information System (INIS)

    Gosset, J.

    1980-10-01

    'Diogene' is the name we have chosen for a 4π solid angle detector, based on a Time Projection Chamber (TPC), designed to perform exclusive measurements of charged particles emitted in central collisions or relativistic heavy ions This detector is being developed by a collaboration between physicists from Saclay, Strasbourg and Clermont-Ferrand, to be installed at the Saturne Synchrotron in Saclay. I shall first give the motivations for our choice of a TPC rather than any other kind of detector, than recall the principle of such a detector, before describing it with more detail and describing its present status and forsean capabilities, including some discussion about the possible extension of such a detector towards higher energies and/or heavier beams

  19. STAR PIXEL detector mechanical design

    Energy Technology Data Exchange (ETDEWEB)

    Wieman, H H; Anderssen, E; Greiner, L; Matis, H S; Ritter, H G; Sun, X; Szelezniak, M [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States)], E-mail: hhwieman@lbl.gov

    2009-05-15

    A high resolution pixel detector is being designed for the STAR [1] experiment at RHIC. This device will use MAPS as the detector element and will have a pointing accuracy of {approx}25 microns. We will be reporting on the mechanical design required to support this resolution. The radiation length of the first layer ({approx}0.3% X{sub 0}) and its distance from the interaction point (2.5 cm) determines the resolution. The design makes use of air cooling and thin carbon composite structures to limit the radiation length. The mechanics are being developed to achieve spatial calibrations and stability to 20 microns and to permit rapid detector replacement in event of radiation damage or other potential failures from operation near the beam.

  20. Detector Developments for the High Luminosity LHC Era (2/4)

    CERN Multimedia

    CERN. Geneva

    2010-01-01

    Calorimetry and Muon Spectromers - Part II: When upgrading the LHC to higher luminosities, the detector and trigger performance shall be preserved - if not improved - with respect to the nominal performance. The ongoing R&D for new radiation tolerant front-end electronics for calorimeters with higher read-out bandwidth are summarized and new possibilities for the trigger systems are presented. Similar developments are foreseen for the muon spectrometers, where also radiation tolerance of the muon detectors and functioning at high background rates is important. The corresponding plans and research work for the calorimeter and muon detectors at a LHC with highest luminsity are presented.

  1. Signal Attenuation Curve for Different Surface Detector Arrays

    Science.gov (United States)

    Vicha, J.; Travnicek, P.; Nosek, D.; Ebr, J.

    2014-06-01

    Modern cosmic ray experiments consisting of large array of particle detectors measure the signals of electromagnetic or muon components or their combination. The correction for an amount of atmosphere passed is applied to the surface detector signal before its conversion to the shower energy. Either Monte Carlo based approach assuming certain composition of primaries or indirect estimation using real data and assuming isotropy of arrival directions can be used. Toy surface arrays of different sensitivities to electromagnetic and muon components are assumed in MC simulations to study effects imposed on attenuation curves for varying composition or possible high energy anisotropy. The possible sensitivity of the attenuation curve to the mass composition is also tested for different array types focusing on a future apparatus that can separate muon and electromagnetic component signals.

  2. Precise measurement of internal sense-wire locations in high-energy physics detectors

    International Nuclear Information System (INIS)

    Dunn, W.L.; O'Foghludha, F.; Yacount, A.M.

    1992-01-01

    Cylindrical straw tubes that contain central sense wires (as anodes) are commonly employed in high-energy and nuclear physics experiments to track charged particles through regions of large detectors. The outer tracking region of the proposed Solenoidal Detector Collaboration (SDC) detector for future experiments at the Superconducting Super Collider (SSC), for instance, is expected to contain more than a hundred thousand 4-mm-diam straw tube drift cells arranged in five cylindrically concentric superlayers. The superlayers will be made up of modules having roughly trapezoidal cross sections. The modules will be up to 4 m long and will contain ∼200 straws each, arranged in either six or eight layers. The module shells are expected to be made of thin but nontransparent carbon/epoxy composite material and the straws of mylar or kapton, which has been coated on the inside with a thin (∼0.15-μm) layer of copper. A precise knowledge of the locations of the sense wires in these modules is crucial to the intended particle tracking

  3. An Optimized Design of Single-Channel Beta-Gamma Coincidence Phoswich Detector by Geant4 Monte Carlo Simulations

    Directory of Open Access Journals (Sweden)

    Weihua Zhang

    2011-01-01

    Full Text Available An optimized single-channel phoswich well detector design has been proposed and assessed in order to improve beta-gamma coincidence measurement sensitivity of xenon radioisotopes. This newly designed phoswich well detector consists of a plastic beta counting cell (BC404 embedded in a CsI(Tl crystal coupled to a photomultiplier tube. The BC404 is configured in a cylindrical pipe shape to minimise light collection deterioration. The CsI(Tl crystal consists of a rectangular part and a semicylindrical scintillation part as a light reflector to increase light gathering. Compared with a PhosWatch detector, the final optimized detector geometry showed 15% improvement in the energy resolution of a 131mXe 129.4 keV conversion electron peak. The predicted beta-gamma coincidence efficiencies of xenon radioisotopes have also been improved accordingly.

  4. A silicon pixel detector prototype for the CLIC vertex detector

    CERN Multimedia

    AUTHOR|(INSPIRE)INSPIRE-00714258

    2017-01-01

    A silicon pixel detector prototype for CLIC, currently under study for the innermost detector surrounding the collision point. The detector is made of a High-Voltage CMOS sensor (top) and a CLICpix2 readout chip (bottom) that are glued to each other. Both parts have a size of 3.3 x 4.0 $mm^2$ and consist of an array of 128 x 128 pixels of 25 x 25 $\\micro m^2$ size.

  5. Dosimetric characteristics of Li2B4O7:Cu,Ag,P solid TL detectors

    International Nuclear Information System (INIS)

    Proki, M.

    2002-01-01

    The main dosimetric characteristics are presented of newly prepared tissue-equivalent, highly sensitive thermoluminescent detector, Li 2 B 4 O 7 :Cu,Ag,P in the form of sintered pellets, developed at the Institute of Nuclear Sciences, Vin a . As a result of an advancement in the preparation procedure by the sensitising of basic copper activated lithium borate TL material, significant improvement in the TL sensitivity of Li 2 B 4 O 7 :Cu,Ag,P was gained. The glow curve of Li 2 B 4 O 7 :Cu,Ag,P consists of well defined main dosimetric peak situated at about 185-190 deg. C with the TL sensitivity which is about four to five times higher than that of LiF:Mg,Ti (TLD-100). From the experimental results a very wide linear dose response range, up to 10 3 Gy is evident. Dosimetric characteristics make sintered solid Li 2 B 4 O 7 :Cu,Ag,P TL detectors very promising for different dosimetry applications particularly in medical dosimetry and also for individual monitoring. (author)

  6. FE-I4 Firmware Development and Integration with FELIX for the Pixel Detector

    CERN Document Server

    Yadav, Amitabh; Sharma, Abhishek; CERN. Geneva. EP Department

    2017-01-01

    CERN has planned a series of upgrades for the LHC. The last in this current series of planned upgrades is designated the HL-LHC. At the same time, the ATLAS Experiment will be extensively changed to meet the challenges of this upgrade (termed as the “Phase-II” upgrade). The Inner Detector will be completely rebuilt for the phase-II. The TRT, SCT and Pixel will be replaced by the all-silicon tracker, termed as the Inner Tracker (ITk). The read-out of this future ITk detector is an engineering challenge for the routing of services and quality of the data. This document describes the FPGA firmware development that integrates the GBT, Elink and Rx-Tx Cores for communication between the FE-I4 modules and the FELIX read-out system.

  7. Structural phase transition and magnetic properties of double perovskites Ba2CaMO6 (M=W, Re, Os)

    International Nuclear Information System (INIS)

    Yamamura, Kazuhiro; Wakeshima, Makoto; Hinatsu, Yukio

    2006-01-01

    Structures and magnetic properties for double perovskites Ba 2 CaMO 6 (M=W, Re, Os) were investigated. Both Ba 2 CaReO 6 and Ba 2 CaWO 6 show structural phase transitions at low temperatures. For Ba 2 CaReO 6 , the second order transition from cubic Fm3-bar m to tetragonal I4/m has been observed near 120K. For Ba 2 CaWO 6 , the space group of the crystal structure is I4/m at 295K and the transition to monoclinic I2/m has been observed between 220K. Magnetic susceptibility measurements show that Ba 2 CaReO 6 (S=1/2) and Ba 2 CaOsO 6 (S=1) transform to an antiferromagnetic state below 15.4 and 51K, respectively. Anomalies corresponding to their structural phase transition and magnetic transition have been also observed through specific heat measurements

  8. Hot pressing of B4C/SiC composites

    International Nuclear Information System (INIS)

    Sahin, F.C.; Turhan, E.; Yesilcubuk, S.A.; Addemir, O.

    2005-01-01

    B 4 C/SiC ceramic composites containing 10-20-30 vol % SiC were prepared by hot pressing method. The effect of SiC addition and hot pressing temperature on sintering behaviour and mechanical properties of hot pressed composites were investigated. Microstructures of hot pressed samples were examined by SEM technique. Three different temperatures (2100 deg. C, 2200 deg. C and 2250 deg. C) were used to optimize hot pressing temperature applying 100 MPa pressure under argon atmosphere during the sintering procedure. The highest relative density of 98.44 % was obtained by hot pressing at 2250 deg. C. However, bending strengths of B 4 C/SiC composite samples were lower than monolithic B 4 C in all experimental conditions. (authors)

  9. Synthesis of Poly(3,4-Ethylenedioxy thiophene)-Poly(Styrene-4-Sulfonate) Composites for Support Fuel Cell Catalyst Layer

    International Nuclear Information System (INIS)

    Eko Sulistiyono; Murni Handayani

    2009-01-01

    Synthesis of poly(3,4-ethylenedioxy thiophene)-poly(styrene-4-sulfonate) composites for support fuel cell catalyst layer are synthesis composites which become fuel cell catalyst support so that catalyst has optimal performance. Main function of composites is support platinum particle for application in fuel cell. This article explains the result of composites production process from ( 3,4 Ethylenedioxy thiophene) and Sodium poly( styrene - 4-sulfonate) using two methods Jingning Shan method (method 1) and Zhigang Qi and Peter G.Pickup method (method 2). Analysis of the synthesis results used Scanning Electron Microscopic –Electron Dispersive X – Ray Spectrophotometer (SEM-EDS ). The analysis result show that both methods produce polymer agglomerate into a sponge-like morphology. Composite from method 1 has morphology, pores and proton transport better than composite produced by method 2. (author)

  10. Melting Behavior and Thermolysis of NaBH4−Mg(BH4)2 and NaBH4−Ca(BH4)2 Composites

    OpenAIRE

    Ley, Morten; Roedern, Elsa; Thygesen, Peter; Jensen, Torben

    2015-01-01

    The physical properties and the hydrogen release of NaBH 4 –Mg(BH 4 ) 2 and NaBH 4 −Ca(BH 4 ) 2 composites are investigated using in situ synchrotron radiation powder X-ray diffraction, thermal analysis and temperature programmed photographic analysis. The composite, x NaBH 4 –(1 − x )Mg(BH 4 ) 2 , x = 0.4 to 0.5, shows melting/frothing between 205 and 220 °C. However, the sample does not become a transparent molten phase. This behavior is similar to other alkali-alkaline earth metal borohydr...

  11. New air Cherenkov light detectors to study mass composition of cosmic rays with energies above knee region

    Energy Technology Data Exchange (ETDEWEB)

    Tsunesada, Yoshiki, E-mail: tsunesada@cr.phys.titech.ac.jp [Graduate School of Science and Engineering, Tokyo Institute of Technology, Meguro, Tokyo 152-8550 Japan (Japan); Katsuya, Ryoichi, E-mail: katsuya@cr.phys.titech.ac.jp [Graduate School of Science and Engineering, Tokyo Institute of Technology, Meguro, Tokyo 152-8550 Japan (Japan); Mitsumori, Yu; Nakayama, Keisuke; Kakimoto, Fumio; Tokuno, Hisao [Graduate School of Science and Engineering, Tokyo Institute of Technology, Meguro, Tokyo 152-8550 Japan (Japan); Tajima, Norio [RIKEN, Wako, Saitama 351-0198 (Japan); Miranda, Pedro; Salinas, Juan; Tavera, Wilfredo [Instituto de Investigaciones Físicas, Universidad Mayor de San Andrés, La Paz (Bolivia, Plurinational State of)

    2014-11-01

    We have installed a hybrid detection system for air showers generated by cosmic rays with energies greater than 3×10{sup 15}eV at Mount Chacaltaya (5200 m above the sea level), in order to study the mass composition of cosmic rays above the knee region. This detection system comprises an air shower array with 49 scintillation counters in an area of 500 m×650 m, and seven new Cherenkov light detectors installed in a radial direction from the center of the air shower array with a separation of 50 m. It is known that the longitudinal development of a particle cascade in the atmosphere strongly depends on the type of the primary nucleus, and an air shower initiated by a heavier nucleus develops faster than that by a lighter primary of the same energy, because of the differences in the interaction cross-section and the energy per nucleon. This can be measured by detecting the Cherenkov radiation emitted from charged particles in air showers at higher altitudes. In this paper we describe the design and performance of our new non-imaging Cherenkov light detectors at Mount Chacaltaya that are operated in conjunction with the air shower array. The arrival directions and energies of air showers are determined by the shower array, and information about the primary masses is obtained from the Cherenkov light data including the time profiles and lateral distributions. The detector consists of photomultiplier tube (PMT), high-speed ADCs, other control modules, and data storage device. The Cherenkov light signals from an air shower are typically 10–100 ns long, and the waveforms are digitized with a sampling frequency of 1 GHz and recorded in situ without long-distance analog signal transfers. All the Cherenkov light detectors record their time-series data by receiving a triggering signal transmitted from the trigger module of the air shower array, which is fired by a coincidence of shower signals in four neighboring scintillation counters. The optical characteristics of the

  12. Upconversion detector for methane atmospheric sensor

    DEFF Research Database (Denmark)

    Meng, Lichun; Fix, Andreas; Høgstedt, Lasse

    2017-01-01

    We demonstrate an efficient upconversion detector (UCD) for a methane (CH4) atmospheric sensor. The UCD shows comparable performance with a conventional detector when measuring the backscattered signal from the hard target located 2.3 km away.......We demonstrate an efficient upconversion detector (UCD) for a methane (CH4) atmospheric sensor. The UCD shows comparable performance with a conventional detector when measuring the backscattered signal from the hard target located 2.3 km away....

  13. Diogene, a 4π detector for the heavy ion physics with Saturne

    International Nuclear Information System (INIS)

    Alard, J.P.; Augerat, J.; Babinet, R.

    A 4π-detection set up is presently being built around the Saturne II facility, to study central collisions between high energy heavy ions. This set up is essentially composed of a cylindrical drift chamber, triggered by a 30-scintillators multiplicity filter. A schematic description of the detector is given first. Then the present status of the project is presented, at last some progresses on track reconstruction technique with simulated events are given [fr

  14. Luminescent properties of red-light-emitting phosphors CaWO4 : Eu ...

    Indian Academy of Sciences (India)

    Department of Optoelectronics, Xiamen University of Technology, Xiamen, Fujian 361024, China ... chips, but its disadvantage is high cost, different drive volt- age, and different ..... Provincial Education Department (Grant nos JA12242 and.

  15. Irradiation induced effects in the FE-I4 front-end chip of the ATLAS IBL detector

    CERN Document Server

    La Rosa, Alessandro; The ATLAS collaboration

    2016-01-01

    The ATLAS Insertable B-Layer (IBL) detector was installed into the ATLAS experiment in 2014 and has been in operation since 2015. During the first year of IBL data taking an increase of the low voltage currents produced by the FE-I4 front-end chip was observed and this increase was traced back to the radiation damage in the chip. The dependence of the current on the total-ionising dose and temperature has been tested with Xray and proton irradiations and will be presented in this paper together with the detector operation guidelines.

  16. R&D studies of a RICH detector using pressurized C$_{4}$F$_{8}$O radiator gas and a CsI-based gaseous photon detector

    CERN Document Server

    Agócs, A.G; Barnaföldi, G.G; Bellwied, R; Bencédi, G; Bencze, G; Berényi, D; Boldizsár, L; Chattopadhyay, S; Chinellato, D.D; Cindolo, F; Das-Bose, L; Das, D; Das, K; De Cataldo, G; Di Bari, D; Di Mauro, A; Futó, E; Garcia, E; Hamar, G; Harton, A; Jimenez, R.T; Kim, D.W; Kim, J.S; Knospe, A; Kovacs, L; Lévai, P; Markert, C; Martinengo, P; Molnar, L; Nappi, E; Olah, L; Paic, G; Pastore, C; Patino, M.E; Peskov, V; Pinsky, L; Piuz, F; Pochybova, S; Sgura, I; Sinha, T; Song, J; Timmins, A; Van Beelen, J.B; Varga, D; Volpe, G; Weber, M; Xaplanteris, L; Yi, J; Yoo, I.-K

    2013-01-01

    We report on studies of layout and performance of a new Ring Imaging Cherenkov detector using for the fi rst time pressurized C 4 F 8 O radiator gas and a photon detector consisting of a MWPC equipped with a CsI photocathode. In particular, we present here the results of beam tests of a MWPC having an adjustable anode – cathode gap, aiming at the optimization of single photoelectron detection and Cherenkov angle resolution. This system was proposed as a Very High Momentum Particle Identi fi cation (VHMPID) upgrade for the ALICE experiment at LHC to provide charged hadron track-by-track identi fi cation in the momentum range 5 – 25 GeV/c.

  17. A 2D 4×4 Channel Readout ASIC for Pixelated CdTe Detectors for Medical Imaging Applications.

    Science.gov (United States)

    Macias-Montero, Jose-Gabriel; Sarraj, Maher; Chmeissani, Mokhtar; Martínez, Ricardo; Puigdengoles, Carles

    2015-10-01

    We present a 16-channel readout integrated circuit (ROIC) with nanosecond-resolution time to digital converter (TDC) for pixelated Cadmium Telluride (CdTe) gamma-ray detectors. The 4 × 4 pixel array ROIC is the proof of concept of the 10 × 10 pixel array readout ASIC for positron-emission tomography (PET) scanner, positron-emission mammography (PEM) scanner, and Compton gamma camera. The electronics of each individual pixel integrates an analog front-end with switchable gain, an analog to digital converter (ADC), configuration registers, and a 4-state digital controller. For every detected photon, the pixel electronics provides the energy deposited in the detector with 10-bit resolution, and a fast trigger signal for time stamp. The ASIC contains the 16-pixel matrix electronics, a digital controller, five global voltage references, a TDC, a temperature sensor, and a band-gap based current reference. The ASIC has been fabricated with TSMC 0.25 μ m mixed-signal CMOS technology and occupies an area of 5.3 mm × 6.8 mm. The TDC shows a resolution of 95.5 ps, a precision of 600 ps at full width half maximum (FWHM), and a power consumption of 130 μ W. In acquisition mode, the total power consumption of every pixel is 200 μ W. An equivalent noise charge (ENC) of 160 e - RMS at maximum gain and negative polarity conditions has been measured at room temperature.

  18. Inferences on mass composition and tests of hadronic interactions from 0.3 to 100 EeV using the water-Cherenkov detectors of the Pierre Auger Observatory

    NARCIS (Netherlands)

    Aab, A.; Abreu, P.; Aglietta, M.; Al Samarai, I.; Albuquerque, I.F.M.; Allekotte, I.; Almela, M.; Zuccarello, F.; van den Berg, Adriaan; Scholten, Olaf

    2017-01-01

    We present a new method for probing the hadronic interaction models atultrahigh energy and extracting details about mass composition. This isdone using the time profiles of the signals recorded with thewater-Cherenkov detectors of the Pierre Auger Observatory. The profilesarise from a mix of the

  19. Preparation of gelatin-assisted polypyrrole-poly(3,4-ethylenedioxythiophene) composites

    Energy Technology Data Exchange (ETDEWEB)

    Jo, Eun Jin; Male, Umashankar; Huh, Do Sung [Dept.of Chemistry and Nanosystem Engineering, Center for Nano Manufacturing, Inje University, Kimhae (Korea, Republic of)

    2016-11-15

    Conductive polymer composite was synthesized by the polymerization of pyrrole with 3,4-ethylenedioxythiophene using ammonium persulfate as an oxidant with different concentrations of gelatin dispersed in aqueous medium along with the polymerization. Differently from pure polypyrrole–poly(3,4-ethylenedioxythiophene) (PPy–PEDOT) copolymer, the gelatin-assisted composites showed good solubility in aqueous media. The prepared PPy–PEDOT/gelatin composites were identified with Fourier-transform infrared, UV–visible spectroscopy, and X-ray diffraction. Morphological analysis and temperature-dependent direct current conductivity of PPy–PEDOT/gelatin composites were carried out. Obtained results revealed that added gelatin greatly increased conductivity due to the improved mobility of charge carriers.

  20. High efficiency scintillation detectors

    International Nuclear Information System (INIS)

    Noakes, J.E.

    1976-01-01

    A scintillation counter consisting of a scintillation detector, usually a crystal scintillator optically coupled to a photomultiplier tube which converts photons to electrical pulses is described. The photomultiplier pulses are measured to provide information on impinging radiation. In inorganic crystal scintillation detectors to achieve maximum density, optical transparency and uniform activation, it has been necessary heretofore to prepare the scintillator as a single crystal. Crystal pieces fail to give a single composite response. Means are provided herein for obtaining such a response with crystal pieces, such means comprising the combination of crystal pieces and liquid or solid organic scintillator matrices having a cyclic molecular structure favorable to fluorescence. 8 claims, 6 drawing figures

  1. Fiberglass Composite Blades for the 4 MW - WTS-4 Wind Turbine

    Science.gov (United States)

    Bussolari, R. J.

    1982-01-01

    The design and fabrication of composite blades for the WTS-4, a four-megawatt horizontal-axis wind turbine, is discussed. The blade consists of a two-cell, monolithic structure of filament-wound, fiberglass/epoxy composite. Filament winding is a low-cost process which can produce a blade with an aerodynamically efficient airfoil and planform with nonlinear twist to achieve high performance in terms of energy capture. Its retention provides a redundant attachment for long, durable life and safety. Advanced tooling concepts and as sophisticated computer control is used to achieve the unique filament-wound shape.

  2. The silicon shower maximum detector for the STIC

    International Nuclear Information System (INIS)

    Alvsvaag, S.J.; Maeland, O.A.; Klovning, A.

    1995-01-01

    The structure of a shashlik calorimeter allows the insertion of tracking detectors within the longitudinal sampling to improve the accuracy in the determination of the direction of the showering particle and the e/π separation ability. The new forward calorimeter of the DELPHI detector has been equipped with two planes of silicon pad detectors respectively after 4 and 7.4 radiation lengths. The novelty of these silicon detectors is that to cope with the shashlik readout fibers, they had to incorporate 1.4 mm holes every cm 2 . The detector consists of circular strips with a radial pitch of 1.7 mm and an angular granularity of 22.5 , read out by means of the MX4 preamplifier. The preamplifier is located at 35 cm from the silicon detector and the signal is carried by Kapton cables bonded to the detector. The matching to the MX4 input pitch of 44 μm was made by a specially developed fanin hybrid. (orig.)

  3. LCDD: A complete detector description package

    Energy Technology Data Exchange (ETDEWEB)

    Graf, Norman, E-mail: Norman.Graf@slac.stanford.edu; McCormick, Jeremy, E-mail: Jeremy.McCormick@slac.stanford.edu

    2015-07-21

    LCDD has been developed to provide a complete detector description package for physics detector simulations using Geant4. All aspects of the experimental setup, such as the physical geometry, magnetic fields, and sensitive detector readouts, as well as control of the physics simulations, such as physics processes, interaction models and kinematic limits, are defined at runtime. Users are therefore able to concentrate on the design of the detector system without having to master the intricacies of C++ programming or being proficient in setting up their own Geant4 application. We describe both the XML-based file format and the processors which communicate this information to the underlying Geant4 simulation toolkit.

  4. 42 CFR 52h.4 - Composition of peer review groups.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Composition of peer review groups. 52h.4 Section... PEER REVIEW OF RESEARCH GRANT APPLICATIONS AND RESEARCH AND DEVELOPMENT CONTRACT PROJECTS § 52h.4 Composition of peer review groups. (a) To the extent applicable, the selection and appointment of members of...

  5. Energy spectra analysis of the four-layer DOI detector for the brain PET scanner: jPET-D4

    International Nuclear Information System (INIS)

    Yoshida, Eiji; Kitamura, Keishi; Tsuda, Tomoaki; Shibuya, Kengo; Yamaya, Taiga; Inadama, Naoko; Hasegawa, Tomoyuki; Murayama, Hideo

    2006-01-01

    A depth of interaction (DOI) detector is being developed for the brain PET scanner, jPET-D4. We introduce a light output correction procedure to compensate for variations among the crystal elements in the DOI detector. Under uniform irradiation with 511 keV gamma rays, we estimate the light output of each crystal element by identifying each crystal element, and generate a look-up table (LUT) for light output correction. We evaluate the energy resolution of all crystal elements. The energy resolution of 16% is achieved after light output correction for all crystal elements. The DOI detector can correct light output variations that are related to the DOI. We analyze the crystal position dependence of the energy spectra due to inter-crystal scattering among the multiple crystal elements in the DOI detector. It is highly possible that gamma rays interacting with central crystal elements in the crystal array are absorbed by surrounding crystal elements and the Compton part of the energy spectrum is decreased. Inter-crystal scattering has less impact on the energy resolution of the DOI detector

  6. Overview of data filtering/acquisition for a 4π detector at the SSC

    International Nuclear Information System (INIS)

    Lankford, A.J.; Dubois, G.P.

    1986-01-01

    The task of the Data Filtering/Acquisition Working Group was to examine the feasibility of acquiring data at the Superconducting Super Collider (SSC) event rates from a 4detector with approximately three-quarters of a million electronic channels. An overview of the work on data filtering and acquisition is provided. The assumptions made about the detector, event rates, and event sizes are reviewed, and the overall picture of data flow through the data acqisition system is outlined. The problems of and the general approach to handling of the data during the analog and higher level trigger decision periods are described. The flow of the data to the online processor farm is sketched. Comments are made on software trigger strategies. Some aspects of the overall picture of a generic data acquisition system are sketched. Major issues and some needed develoments are summarized. 12 refs., 3 figs

  7. Particle tracking at 4 K: The Fast Annihilation Cryogenic Tracking (FACT) detector for the AEgIS antimatter gravity experiment

    Energy Technology Data Exchange (ETDEWEB)

    Storey, J., E-mail: james.storey@cern.ch [Albert Einstein Center for Fundamental Physics, Laboratory for High Energy Physics, University of Bern, 3012 Bern (Switzerland); Canali, C. [University of Zurich, Physics Institute, Winterthurerstrasse 190, 8057 Zurich (Switzerland); Aghion, S. [Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano (Italy); Istituto Nazionale di Fisica Nucleare, Sez. di Milano, Via Celoria 16, 20133 Milano (Italy); Ahlén, O. [European Organisation for Nuclear Research, Physics Department, 1211 Geneva 23 (Switzerland); Amsler, C.; Ariga, A.; Ariga, T. [Albert Einstein Center for Fundamental Physics, Laboratory for High Energy Physics, University of Bern, 3012 Bern (Switzerland); Belov, A.S. [Institute for Nuclear Research of the Russian Academy of Sciences, Moscow 117312 (Russian Federation); Bonomi, G. [University of Brescia, Department of Mechanical and Industrial Engineering, Via Branze 38, 25133 Brescia (Italy); Istituto Nazionale di Fisica Nucleare, Sez. di Pavia, Via Agostino Bassi 6, 27100 Pavia (Italy); Bräunig, P. [University of Heidelberg, Kirchhoff Institute for Physics, Im Neuenheimer Feld 227, 69120 Heidelberg (Germany); Bremer, J. [European Organisation for Nuclear Research, Physics Department, 1211 Geneva 23 (Switzerland); Brusa, R.S. [Dipartimento di Fisica, Università di Trento and INFN, Gruppo Collegato di Trento, Via Sommarive 14, 38050 Povo, Trento (Italy); Burghart, G. [European Organisation for Nuclear Research, Physics Department, 1211 Geneva 23 (Switzerland); Cabaret, L. [Laboratoire Aimé Cotton, CNRS, Université Paris Sud, ENS Cachan, Bâtiment 505, Campus d' Orsay, 91405 Orsay Cedex (France); Carante, M. [Istituto Nazionale di Fisica Nucleare, Sez. di Pavia, Via Agostino Bassi 6, 27100 Pavia (Italy); Caravita, R. [University of Milano, Department of Physics, Via Celoria 16, 20133 Milano (Italy); and others

    2013-12-21

    The AEgIS experiment is an international collaboration with the main goal of performing the first direct measurement of the Earth's gravitational acceleration on antimatter. Critical to the success of AEgIS is the production of cold antihydrogen (H{sup ¯}) atoms. The FACT detector is used to measure the production and temperature of the H{sup ¯} atoms and for establishing the formation of a H{sup ¯} beam. The operating requirements for this detector are very challenging: it must be able to identify each of the thousand or so annihilations in the 1 ms period of pulsed H{sup ¯} production, operate at 4 K inside a 1 T solenoidal field and not produce more than 10 W of heat. The FACT detector consists of two concentric cylindrical layers of 400 scintillator fibres with a 1 mm diameter and a 0.6 mm pitch. The scintillating fibres are coupled to clear fibres which transport the scintillation light to 800 silicon photomultipliers. Each silicon photomultiplier signal is connected to a linear amplifier and a fast discriminator, the outputs of which are sampled continuously by Field Programmable Gate Arrays (FPGAs). In the course of the developments for the FACT detector we have established the performance of scintillating fibres at 4 K by means of a cosmic-ray tracker operating in a liquid helium cryostat. The FACT detector was installed in the AEgIS apparatus in December 2012 and will be used to study the H{sup ¯} formation when the low energy antiproton physics programs resume at CERN in the Summer of 2014. This paper presents the design requirements and construction methods of the FACT detector and provides the first results of the detector commissioning.

  8. Particle tracking at 4 K: The Fast Annihilation Cryogenic Tracking (FACT) detector for the AEgIS antimatter gravity experiment

    International Nuclear Information System (INIS)

    Storey, J.; Canali, C.; Aghion, S.; Ahlén, O.; Amsler, C.; Ariga, A.; Ariga, T.; Belov, A.S.; Bonomi, G.; Bräunig, P.; Bremer, J.; Brusa, R.S.; Burghart, G.; Cabaret, L.; Carante, M.; Caravita, R.

    2013-01-01

    The AEgIS experiment is an international collaboration with the main goal of performing the first direct measurement of the Earth's gravitational acceleration on antimatter. Critical to the success of AEgIS is the production of cold antihydrogen (H ¯ ) atoms. The FACT detector is used to measure the production and temperature of the H ¯ atoms and for establishing the formation of a H ¯ beam. The operating requirements for this detector are very challenging: it must be able to identify each of the thousand or so annihilations in the 1 ms period of pulsed H ¯ production, operate at 4 K inside a 1 T solenoidal field and not produce more than 10 W of heat. The FACT detector consists of two concentric cylindrical layers of 400 scintillator fibres with a 1 mm diameter and a 0.6 mm pitch. The scintillating fibres are coupled to clear fibres which transport the scintillation light to 800 silicon photomultipliers. Each silicon photomultiplier signal is connected to a linear amplifier and a fast discriminator, the outputs of which are sampled continuously by Field Programmable Gate Arrays (FPGAs). In the course of the developments for the FACT detector we have established the performance of scintillating fibres at 4 K by means of a cosmic-ray tracker operating in a liquid helium cryostat. The FACT detector was installed in the AEgIS apparatus in December 2012 and will be used to study the H ¯ formation when the low energy antiproton physics programs resume at CERN in the Summer of 2014. This paper presents the design requirements and construction methods of the FACT detector and provides the first results of the detector commissioning

  9. Comparison of bulk and epitaxial 4H-SiC detectors for radiation hard particle tracking

    CERN Document Server

    Quinn, T; Bruzzi, M; Cunningham, W; Mathieson, K; Moll, M; Nelson, T; Nilsson, H E; Pintillie, I; Rahman, M; Reynolds, L; Sciortino, S; Sellin, P J; Strachan, H; Svensson, B G; Vaitkus, J

    2003-01-01

    Measurements and simulations have been carried out using bulk and epitaxial SiC detectors. Samples were irradiated to fluences of around 10**1**4 hardrons/cm**2. Material of thickness 40um gave a charge collection efficiency of 100% dropping to around 60% at 100mum thickness. Detailed MEDICI simulations incorporated the main defect levels in SiC, the vanadium center, Z-center and a mid-gap level as measured by deep level transient spectroscopy and other techniques. Calculated recombination currents and charge collection efficiencies at varying fluences were comparable to experimental data. The study suggests that SiC detectors will operate up to fluences around 10 **1**6/cm**2 as required by future particle physics experiments.

  10. VHMPID RICH prototype using pressurized C{sub 4}F{sub 8}O radiator gas and VUV photon detector

    Energy Technology Data Exchange (ETDEWEB)

    Acconcia, T.V. [UNICAMP, University of Campinas, Campinas (Brazil); Agócs, A.G. [Wigner RCP of the HAS, Budapest (Hungary); Barile, F. [INFN Sezione di Bari and Universitá degli Studi di Bari, Dipartimento Interateneo di Fisica M. Merlin, Bari (Italy); Barnaföldi, G.G. [Wigner RCP of the HAS, Budapest (Hungary); Bellwied, R. [University of Houston, Houston (United States); Bencédi, G. [Wigner RCP of the HAS, Budapest (Hungary); Bencze, G., E-mail: Gyorgy.Bencze@cern.ch [Wigner RCP of the HAS, Budapest (Hungary); Berényi, D.; Boldizsár, L. [Wigner RCP of the HAS, Budapest (Hungary); Chattopadhyay, S. [Saha Institute, Kolkata (India); Chinellato, D.D. [University of Houston, Houston (United States); Cindolo, F. [University of Salerno, Salerno (Italy); Cossyleon, K. [Chicago State University, Chicago, IL (United States); Das, D.; Das, K.; Das-Bose, L. [Saha Institute, Kolkata (India); Dash, A.K. [UNICAMP, University of Campinas, Campinas (Brazil); D' Ambrosio, S. [University of Salerno, Salerno (Italy); De Cataldo, G. [INFN Sezione di Bari and Universitá degli Studi di Bari, Dipartimento Interateneo di Fisica M. Merlin, Bari (Italy); De Pasquale, S. [University of Salerno, Salerno (Italy); and others

    2014-12-11

    A small-size prototype of a new Ring Imaging Cherenkov (RICH) detector using for the first time pressurized C4F8O radiator gas and a photon detector consisting of MWPC equipped with a CsI photocathode has been built and tested at the PS accelerator at CERN. It contained all the functional elements of the detector proposed as Very High Momentum Particle Identification (VHMPID) upgrade for the ALICE experiment at LHC to provide charged hadron track-by-track identification in the momentum range starting from 5 potentially up to 25 GeV/c. In the paper the equipment and its elements are described and some characteristic test results are shown.

  11. Conductivity And Thermal Stability of Solid Acid Composites CsH2PO4 /NaH2PO4/ SiO2

    International Nuclear Information System (INIS)

    Norsyahida Mohammad; Abu Bakar Mohamad; Abu Bakar Mohamad; Abdul Amir Hassan Kadhum

    2016-01-01

    Solid acid composites CsH 2 PO 4 / NaH 2 PO 4 / SiO 2 with different mole ratios of CsH 2 PO 4 and NaH 2 PO 4 to SiO 2 were synthesized and characterized. Preliminary infrared measurements of CsH 2 PO 4 and its composites indicated that hydrogen bonds breaking and formation were detected between 1710 to 2710 cm -1 , while the rotation of phosphate tetrahedral anions occurred between 900 and 1200 cm -1 . The superprotonic transition of CsH 2 PO 4 / NaH 2 PO 4 / SiO 2 composite was identified at superprotonic temperatures between 230 and 260 degree Celcius, under atmospheric pressure. This study reveals higher conductivity values for composites with higher CsH 2 PO 4 (CDP) content. Solid acid composite CDP 613 appeared as the composite with the highest conductivity that is 7.2x10 -3 S cm -1 at 230 degree Celcius. Thermal stability of the solid acid composites such as temperature of dehydration, melting and decomposition were investigated. The addition of NaH 2 PO 4 lowers the dehydration temperature of the solid acid composites. (author)

  12. Image formation in track-etch detectors: Pt. 4

    International Nuclear Information System (INIS)

    Ilic, Radomir; Najzer, Mitja

    1990-01-01

    The radiographic performance of solid state nuclear track detectors was analysed with respect to image quality. Image quality is expressed in terms of three image quality factors: contrast or gradient of the detector, image unsharpness and detail discernment. Equations for the image quality factors were derived from the radiographic transfer function, taking into account image inhomogeneity caused by statistical fluctuations of track density. To find optimal radiographic conditions for a given application, a single quantity called the figure of radiographic merit was defined. It is expressed as the weighted product of the image quality factors. It was found that optimum image quality of a balanced image, characterized by equal importance of all three image quality factors, is obtained at an exposure value (defined as the product of the average visible track area and track density) of unity. (author)

  13. Mesoporous Fe3O4/hydroxyapatite composite for targeted drug delivery

    International Nuclear Information System (INIS)

    Gu, Lina; He, Xiaomei; Wu, Zhenyu

    2014-01-01

    Highlights: • Mesoporous Fe 3 O 4 /hydroxyapatite composite was synthesized by a simple, efficient and environmental friendly method. • The prepared material had a large surface area, high pore volume, and good magnetic separability. • DOX-loaded Fe 3 O 4 /hydroxyapatite composite exhibited surprising slow drug release behavior and pH-dependent behavior. - Abstract: In this contribution, we introduced a simple, efficient, and green method of preparing a mesoporous Fe 3 O 4 /hydroxyapatite (HA) composite. The as-prepared material had a large surface area, high pore volume, and good magnetic separability, which made it suitable for targeted drug delivery systems. The chemotherapeutic agent doxorubicin (DOX) was used to investigate the drug release behavior of Fe 3 O 4 /HA composite. The drug release profiles displayed a little burst effect and pH-dependent behavior. The release rate of DOX at pH 5.8 was larger than that at pH 7.4, which could be attributed to DOX protonation in acid medium. In addition, the released DOX concentrations remained at 0.83 and 1.39 μg/ml at pH 7.4 and 5.8, respectively, which indicated slow, steady, and safe release rates. Therefore, the as-prepared Fe 3 O 4 /hydroxyapatite composite could be an efficient platform for targeted anticancer drug delivery

  14. Hot pressing of B{sub 4}C/SiC composites

    Energy Technology Data Exchange (ETDEWEB)

    Sahin, F.C.; Turhan, E.; Yesilcubuk, S.A.; Addemir, O. [Ystanbul Technical University, Faculty of Chemistry and Metallurgy, Materials and Metallurgical Engineering Dept., Maslak-Ystanbul (Turkey)

    2005-07-01

    B{sub 4}C/SiC ceramic composites containing 10-20-30 vol % SiC were prepared by hot pressing method. The effect of SiC addition and hot pressing temperature on sintering behaviour and mechanical properties of hot pressed composites were investigated. Microstructures of hot pressed samples were examined by SEM technique. Three different temperatures (2100 deg. C, 2200 deg. C and 2250 deg. C) were used to optimize hot pressing temperature applying 100 MPa pressure under argon atmosphere during the sintering procedure. The highest relative density of 98.44 % was obtained by hot pressing at 2250 deg. C. However, bending strengths of B{sub 4}C/SiC composite samples were lower than monolithic B{sub 4}C in all experimental conditions. (authors)

  15. Ground detectors for the study of cosmic ray showers

    International Nuclear Information System (INIS)

    Salazar, H; Villasenor, L

    2008-01-01

    We describe the work that we have done over the last decade to design and construct instruments to measure properties of cosmic rays in Mexico. We describe the detection of decaying and crossing muons in a water Cherenkov detector and discuss an application of these results to calibrate water Cherenkov detectors. We also describe a technique to separate isolated isolated muons and electrons in water Cherenkov detector. Next we describe the design and performance of a hybrid extensive air shower detector array built on the Campus of the University of Puebla (19 deg. N, 90 deg. W, 800 g/cm 2 ) to measure the energy, arrival direction and composition of primary cosmic rays with energies around 1 PeV

  16. Multilayer detector for operative estimation of spectral composition of neutron fields

    CERN Document Server

    Dedenko, G L; Kaplun, A A; Kolesnikov, S V; Samosadnyj, A V; Samosadnyj, V T

    2002-01-01

    Paper describes measuring and control equipment to detect and to identify neutron sources. The equipment comprises two multilayer detectors based on sup 3 He-counters of slow neutron and poly ethylene moderator of fast neutrons, as well as, intensifiers-signal shapers, power multichannel intensifies, power unit, 8-bit microprocessor base information acquisition and processing system. Paper contains the results of measurements of energy dependence of sensitivity of neutron recording by detector layers with application of monoenergetic neutron fluxes. Difference of the experimental data and the Monte Carlo method base calculation results is 10% maximum

  17. A new configuration of the Moxon-Rae detector based on Si detector

    International Nuclear Information System (INIS)

    Niu, H.; Hsu, J.Y.; Liang, J.H.; Yuan, L.G.

    2002-01-01

    A new Moxon-Rae detector configuration based on Si semiconductor detector was proposed in this paper. Three γ-ray sources, 137 Cs, 60 Co, and 24 Na, were employed to make actual measurements using the new Moxon-Rae detector. The measured pulse height spectra and detection efficiencies were compared with the EGS4 simulated values. The results revealed that the proposed new configuration is indeed a successful method and specially a useful technique for higher energy γ-ray measurement

  18. Operation of a high-purity silicon diode alpha particle detector at 1.4 K

    International Nuclear Information System (INIS)

    Martoff, C.J.; Kaczanowicz, E.; Neuhauser, B.J.; Lopez, E.; Zhang, Y.; Ziemba, F.P.

    1991-01-01

    Detection of alpha particles at temperatures as low as 1.4 K was demonstrated using a specially fabricated Si diode. The diode was 475 mm 2 by 0.280 mm thick, fabricated from high-purity silicon with degenerately doped contacts. This is an important step toward development of dual-mode (ionization plus phonon) silicon detectors for low energy radiation. (orig.)

  19. Operation of a high-purity silicon diode alpha particle detector at 1. 4 K

    Energy Technology Data Exchange (ETDEWEB)

    Martoff, C.J.; Kaczanowicz, E. (Temple Univ., Philadelphia, PA (USA)); Neuhauser, B.J.; Lopez, E.; Zhang, Y. (San Francisco State Univ., CA (USA)); Ziemba, F.P. (Quantrad Corp. (USA))

    1991-03-01

    Detection of alpha particles at temperatures as low as 1.4 K was demonstrated using a specially fabricated Si diode. The diode was 475 mm{sup 2} by 0.280 mm thick, fabricated from high-purity silicon with degenerately doped contacts. This is an important step toward development of dual-mode (ionization plus phonon) silicon detectors for low energy radiation. (orig.).

  20. Scintillation detectors of Alborz-I experiment

    International Nuclear Information System (INIS)

    Pezeshkian, Yousef; Bahmanabadi, Mahmud; Abbasian Motlagh, Mehdi; Rezaie, Masume

    2015-01-01

    A new air shower experiment of the Alborz Observatory, Alborz-I, located at the Sharif University of Technology, Iran, will be constructed in near future. An area of about 30×40 m 2 will be covered by 20 plastic scintillation detectors (each with an area of 50×50 cm 2 ). A series of experiments have been performed to optimize the height of light enclosures of the detectors for this array and the results have been compared to an extended code simulation of these detectors. Operational parameters of the detector obtained by this code are cross checked by the Geant4 simulation. There is a good agreement between the extended-code and Geant4 simulations. We also present further discussions on the detector characteristics, which can be applicable for all scintillation detectors with a similar configuration

  1. Synthesis of spherical LiMnPO4/C composite microparticles

    International Nuclear Information System (INIS)

    Bakenov, Zhumabay; Taniguchi, Izumi

    2011-01-01

    Highlights: → We could prepare LiMnPO 4 /C composites by a novel preparation method. → The LiMnPO 4 /C composites were spherical particles with a mean diameter of 3.65 μm. → The LiMnPO 4 /C composite cathode exhibited 112 mAh g -1 at 0.05 C. → It also showed a good rate capability up to 5 C at room temperature and 55 o C. -- Abstract: Spherical LiMnPO 4 /C composite microparticles were prepared by a combination of spray pyrolysis and spray drying followed by heat treatment and examined as a cathode material for lithium batteries. The structure, morphology and electrochemical performance of the resulting spherical LiMnPO 4 /C microparticles were characterized by X-ray diffraction, field-emission scanning electron microscopy, transmission electronic microscopy and standard electrochemical techniques. The final sample was identified as a single phase orthorhombic structure of LiMnPO 4 and spherical powders with a geometric mean diameter of 3.65 μm and a geometric standard deviation of 1.34. The electrochemical cells contained the spherical LiMnPO 4 /C microparticles exhibited first discharge capacities of 112 and 130 mAh g -1 at 0.05 C at room temperature and 55 o C, respectively. These also showed a good rate capability up to 5 C at room temperature and 55 o C.

  2. THGEM based photon detector for Cherenkov imaging applications

    CERN Document Server

    Alexeev, M; Bradamante, F; Bressan, A; Chiosso, M; Ciliberti, P; Croci, G; Colantoni, M L; Dalla Torre, S; Duarte Pinto, S; Denisov, O; Diaz, V; Ferrero, A; Finger, M; Finger, M Jr; Fischer, H; Giacomini, G; Giorgi, M; Gobbo, B; Heinsius, F H; Herrmann, F; Jahodova, V; Königsmann, K; Lauser, L; Levorato, S; Maggiora, A; Martin, A; Menon, G; Nerling, F; Panzieri, D; Pesaro, G; Polak, J; Rocco, E; Ropelewski, L; Sauli, F; Sbrizzai, G; Schiavon, P; Schill, C; Schopferer, S; Slunecka, M; Sozzi, F; Steiger, L; Sulc, M; Takekawa, S; Tessarotto, F; Wollny, H

    2010-01-01

    We are developing a single photon detector for Cherenkov imaging counters. This detector is based on the use of THGEM electron multipliers in a multilayer design. The major goals of our project are ion feedback suppression down to a few per cent, large gain, fast response, insensitivity to magnetic fields, and a large detector size. We report about the project status and perspectives. In particular, we present a systematic study of the THGEM response as a function of geometrical parameters, production techniques and the gas mixture composition. The first figures obtained from measuring the response of a CsI coated THGEM to single photons are presented.

  3. Particle identification method in the CsI(Tl) scintillator used for the CHIMERA 4 pi detector

    CERN Document Server

    Alderighi, M; Basssini, R; Berceanu, I; Blicharska, J; Boiano, C; Borderie, B; Bougault, R; Bruno, M; Cali, C; Cardella, G; Cavallaro, S; D'Agostino, M; D'andrea, M; Dayras, R; De Filippo, E; Fichera, F; Geraci, E; Giustolisi, F; Grzeszczuk, A; Guardone, N; Guazzoni, P; Guinet, D; Iacono-Manno, M; Kowalski, S; La Guidara, E; Lanchais, A L; Lanzalone, G; Lanzanò, G; Le Neindre, N; Li, S; Maiolino, C; Majka, Z; Manfredi, G; Nicotra, D; Paduszynski, T; Pagano, A; Papa, M; Petrovici, C M; Piasecki, E; Pirrone, S; Politi, G; Pop, A; Porto, F; Rivet, M F; Rosato, E; Sacca, G; Sechi, G; Simion, V; Sperduto, M L; Steckmeyer, J C; Trifiró, A; Trimarchi, M; Urso, S; Vannini, G; Vigilante, M; Wilczynski, J; Wu, H; Xiao, Z; Zetta, L; Zipper, W

    2002-01-01

    The charged particle identification obtained by the analysis of signals coming from the CsI(Tl) detectors of the CHIMERA 4 pi heavy-ion detector is presented. A simple double-gate integration method, with the use of the cyclotron radiofrequency as reference time, results in low thresholds for isotopic particle identification. The dependence of the identification quality on the gate generation timing is discussed. Isotopic identification of light ions up to Beryllium is clearly seen. For the first time also the identification of Z=5 particles is observed. The identification of neutrons interacting with CsI(Tl) by (n,alpha) and (n,gamma) reactions is also discussed.

  4. Detectors - Electronics

    International Nuclear Information System (INIS)

    Bregeault, J.; Gabriel, J.L.; Hierle, G.; Lebotlan, P.; Leconte, A.; Lelandais, J.; Mosrin, P.; Munsch, P.; Saur, H.; Tillier, J.

    1998-01-01

    The reports presents the main results obtained in the fields of radiation detectors and associated electronics. In the domain of X-ray gas detectors for the keV range efforts were undertaken to rise the detector efficiency. Multiple gap parallel plate chambers of different types as well as different types of X → e - converters were tested to improve the efficiency (values of 2.4% at 60 KeV were reached). In the field of scintillators a study of new crystals has been carried out (among which Lutetium orthosilicate). CdTe diode strips for obtaining X-ray imaging were studied. The complete study of a linear array of 8 CdTe pixels has been performed and certified. The results are encouraging and point to this method as a satisfying solution. Also, a large dimension programmable chamber was used to study the influence of temperature on the inorganic scintillators in an interval from -40 deg. C to +150 deg. C. Temperature effects on other detectors and electronic circuits were also investigated. In the report mentioned is also the work carried out for the realization of the DEMON neutron multidetector. For neutron halo experiments different large area Si detectors associated with solid and gas position detectors were realized. In the frame of a contract with COGEMA a systematic study of Li doped glasses was undertaken aiming at replacing with a neutron probe the 3 He counters presently utilized in pollution monitoring. An industrial prototype has been realised. Other studies were related to integrated analog chains, materials for Cherenkov detectors, scintillation probes for experiments on fundamental processes, gas position sensitive detectors, etc. In the field of associated electronics there are mentioned the works related to the multidetector INDRA, data acquisition, software gamma spectrometry, automatic gas pressure regulation in detectors, etc

  5. Cometary Coma Chemical Composition (C4) Mission

    Science.gov (United States)

    Carle, Glenn C.; Clark, Benton C.; Knocke, Philip C.; OHara, Bonnie J.; Adams, Larry; Niemann, Hasso B.; Alexander, Merle; Veverka, Joseph; Goldstein, Raymond; Huebner, Walter; hide

    1994-01-01

    Cometary exploration remains of great importance to virtually all of space science. Because comets are presumed to be remnants of the early solar nebula, they are expected to provide fundamental knowledge as to the origin and development of the solar system as well as to be key to understanding of the source of volatiles and even life itself in the inner solar system. Clearly the time for a detailed study of the composition of these apparent messages from the past has come. A comet rendezvous mission, the Cometary Coma Chemical Composition (C4) Mission, is now being studied as a candidate for the new Discovery program. This mission is a highly-focussed and usefully-limited subset of the Cometary Rendezvous Asteroid Flyby (CRAF) Mission. The C4 mission will concentrate on measurements that will produce an understanding of the composition and physical makeup of a cometary nucleus. The core science goals of the C4 mission are 1) to determine the chemical, elemental, and isotopic composition of a cometary nucleus and 2) to characterize the chemical and isotopic nature of its atmosphere. A related goal is to obtain temporal information about the development of the cometary coma as a function of time and orbital position. The four short-period comets -- Tempel 1, Tempel 2, Churyumov-Gerasimenko, and Wirtanen -which all appear to have acceptable dust production rates, were identified as candidate targets. Mission opportunities have been identified beginning as early as 1998. Tempel I with a launch in 1999, however, remains the baseline comet for studies of and planning the C4 mission. The C4 mission incorporates two science instruments and two engineering instruments in the payload to obtain the desired measurements. The science instruments include an advanced version of the Cometary Ice and Dust Experiment (CIDEX), a mini-CIDEX with a sample collection system, an X-ray Fluorescence Spectrometer and a Pyrolysis-Gas Chromatograph, and a simplified version of the Neutral

  6. Coordinate-sensitive charged particle detector for spectroscopy

    Directory of Open Access Journals (Sweden)

    Sidorenko V. P.

    2016-10-01

    Full Text Available The authors have designed, manufactured and tested a coordinate-sensitive detector for charged particle spectroscopy. The detector can be used in the devices for the elemental analysis of materials, providing simultaneous analysis of all the elemental composition with high sensitivity and precision. The designed device is based on an integrated circuit (IC and a microchannel plate (MCP electron multiplier. The IC is mounted on a ceramic substrate. Ions fall on the MCP mounted above the IC. Giving rise to a pulse which typically exceeds 106 electrons, each ion falls on the detector electrodes and these pulses are counted. In this research, a two stage stack of MCPs (Hamamatsu was used. The MCPs have a channel diameter of 12 μm on a 15 μm pitch. The results of tests carried out in a mass spectrometer are presented. The designed detector is small, light, and low-power.

  7. Directional crystallization of B4C-NbB2 and B4C-MoB2 eutectic compositions

    International Nuclear Information System (INIS)

    Paderno, Varvara; Paderno, Y.B.; Filippov, Vladimir; Liashchenko, Alfred

    2004-01-01

    We studied the directional crystallization of different compositions in B 4 C-NbB 2 and B 4 C-MoB 2 systems. The eutectic compositions for both systems are evaluated. It is shown that in the first system the rod-like eutectic structure is formed, in second, the 'Chinese hieroglyphics'. In both cases high hardness and high microplasticity are observed, which are much more than for individual component phases. These compositions may be considered as a new kind of self-strengthening composite materials

  8. Workshops on radiation imaging detectors

    International Nuclear Information System (INIS)

    Sochinskii, N.V.; Sun, G.C.; Kostamo, P.; Silenas, A.; Saynatjoki, A.; Grant, J.; Owens, A.; Kozorezov, A.G.; Noschis, E.; Van Eijk, C.; Nagarkar, V.; Sekiya, H.; Pribat, D.; Campbell, M.; Lundgren, J.; Arques, M.; Gabrielli, A.; Padmore, H.; Maiorino, M.; Volpert, M.; Lebrun, F.; Van der Putten, S.; Pickford, A.; Barnsley, R.; Anton, M.E.G.; Mitschke, M.; Gros d'Aillon, E.; Frojdh, C.; Norlin, B.; Marchal, J.; Quattrocchi, M.; Stohr, U.; Bethke, K.; Bronnimann, C.H.; Pouvesle, J.M.; Hoheisel, M.; Clemens, J.C.; Gallin-Martel, M.L.; Bergamaschi, A.; Redondo-Fernandez, I.; Gal, O.; Kwiatowski, K.; Montesi, M.C.; Smith, K.

    2005-01-01

    This document gathers the transparencies that were presented at the international workshop on radiation imaging detectors. 9 sessions were organized: 1) materials for detectors and detector structure, 2) front end electronics, 3) interconnected technologies, 4) space, fusion applications, 5) the physics of detection, 6) industrial applications, 7) synchrotron radiation, 8) X-ray sources, and 9) medical and other applications

  9. Workshops on radiation imaging detectors

    Energy Technology Data Exchange (ETDEWEB)

    Sochinskii, N V; Sun, G C; Kostamo, P; Silenas, A; Saynatjoki, A; Grant, J; Owens, A; Kozorezov, A G; Noschis, E; Van Eijk, C; Nagarkar, V; Sekiya, H; Pribat, D; Campbell, M; Lundgren, J; Arques, M; Gabrielli, A; Padmore, H; Maiorino, M; Volpert, M; Lebrun, F; Van der Putten, S; Pickford, A; Barnsley, R; Anton, M E.G.; Mitschke, M; Gros d' Aillon, E; Frojdh, C; Norlin, B; Marchal, J; Quattrocchi, M; Stohr, U; Bethke, K; Bronnimann, C H; Pouvesle, J M; Hoheisel, M; Clemens, J C; Gallin-Martel, M L; Bergamaschi, A; Redondo-Fernandez, I; Gal, O; Kwiatowski, K; Montesi, M C; Smith, K

    2005-07-01

    This document gathers the transparencies that were presented at the international workshop on radiation imaging detectors. 9 sessions were organized: 1) materials for detectors and detector structure, 2) front end electronics, 3) interconnected technologies, 4) space, fusion applications, 5) the physics of detection, 6) industrial applications, 7) synchrotron radiation, 8) X-ray sources, and 9) medical and other applications.

  10. In-Situ Preparation and Magnetic Properties of Fe3O4/WOOD Composite

    Science.gov (United States)

    Gao, Honglin; Zhang, Genlin; Wu, Guoyuan; Guan, Hongtao

    2011-06-01

    Fe3O4/wood composite, a magnetic material, was prepared by In-situ chemosynthesis method at room temperature. The X-ray diffraction (XRD) shows that the average partical size of Fe3O4 was about 14 nm. The magnetic properties of the resulting composites were investigated by vibrating sample magnetometer (VSM). The composites have saturation magnetization (Ms) values from 4.7 to 25.3 emu/g with the increase of weight percent gains (WPG) of the wood for the composites, but coercive forces (Hc) are invariable, which is different from the magnetic materials reported before. It may be due to the fact that the interaction between wood and Fe3O4 becomes stronger when less of Fe3O4 particles are introduced in the composition, and this also changes the surface anisotropy (Ks) of the magnetism. A structural characterization by Fourier transform infrared (FTIR) proved the interaction between Fe3O4 particles and wood matrix, and it also illustrates that this interaction influences the coercive force of the composite.

  11. Electrodeposited Mn3O4-NiO-Co3O4 as a composite electrode material for electrochemical capacitor

    International Nuclear Information System (INIS)

    Rusi; Majid, S.R.

    2015-01-01

    Highlights: • Composite electrodes were synthesized by in situ electrodeposition method. • The highest specific capacitance of composite electrode is 7404 F g −1 . • The power density of composite electrode is 99 kW kg −1 at current density of 20 A g −1 . • The addition of K 3 Fe(CN) 6 in KOH electrolyte has improved the electrochemical performance. - Abstract: A simple and easy galvanostatic electrodeposition method is used to synthesise a composite electrode consisting of manganese oxide (Mn 3 O 4 ), nickel oxide (NiO) and cobalt oxide (Co 3 O 4 ). The influence of Co 3 O 4 on the morphology of fixed Mn 3 O 4 -NiO particles is investigated with a field emission scanning electron microscope (FESEM) and transmission electron microscope (TEM). The nature and elemental of the composite are examined by means of X-ray diffraction (XRD) and energy dispersive X-ray spectroscopy (EDX). The electrochemical performances of an Mn 3 O 4 -NiO-Co 3 O 4 nanostructure/SS composite electrode are studied by cyclic voltammetry (CV) and galvanostatic charge-discharge (CD) in various electrolytes, i.e. 0.5 M Na 2 SO 4 , 0.5 M KOH, 0.5 M Na 2 SO 4 /0.04 M K 3 Fe(CN) 6 and 0.5 M KOH/0.04 M K 3 Fe(CN) 6 electrolytes. The composite electrode prepared from 0.15 M Co deposition solution exhibits the optimum specific capacitance of 7404 F g −1 with high energy and power density of 1028 Wh kg −1 and 99 kW kg −1 at 20 A g −1 in mix KOH/0.04 M K 3 Fe(CN) 6 electrolyte, respectively. The results show that the incorporation of K 3 Fe(CN) 6 in KOH electrolyte influences the capacitance of Mn 3 O 4 -NiO-Co 3 O 4 composite electrodes

  12. Development of hybrid low-pressure MSGC neutron detectors

    International Nuclear Information System (INIS)

    Gebauer, B.; Alimov, S.S.; Klimov, A.Yu.; Levchanovski, F.V.; Litvinenko, E.I.; Nikiforov, A.S.; Prikhodko, V.I.; Richter, G.; Rogov, V.; Schulz, Ch.; Shashkin, V.I.; Wilhelm, M.; Wilpert, Th.

    2004-01-01

    For very high rate and resolution time-resolved experiments at next generation pulsed spallation neutron sources like ESS large-area hybrid low-pressure micro-strip gas chamber detectors are being developed. Due to their thin composite converter foil and exponential gas multiplication commencing at the converter surfaces the detectors are free of parallax, and according to detailed modeling the very high transverse and longitudinal localization accuracies in the conversion and gas multiplication processes allow position and time resolutions of ∼100 μm and 8 cps. This will open up novel applications based on time-of-flight (TOF) and single-event detection with very high dynamic range, replacing integrating CCD and image plate detectors, e.g. in radiography/tomography, TOF Laue diffraction, single crystal diffraction and focusing low-Q SANS. In this conference report new results concerning the technical realization of this detector system are reported in conjunction with a brief summary of the detector principle and with reference to earlier results

  13. Ultrafast, superhigh gain visible-blind UV detector and optical logic gates based on nonpolar a-axial GaN nanowire

    Science.gov (United States)

    Wang, Xingfu; Zhang, Yong; Chen, Xinman; He, Miao; Liu, Chao; Yin, Yian; Zou, Xianshao; Li, Shuti

    2014-09-01

    Nonpolar a-axial GaN nanowire (NW) was first used to construct the MSM (metal-semiconductor-metal) symmetrical Schottky contact device for application as visible-blind ultraviolet (UV) detector. Without any surface or composition modifications, the fabricated device demonstrated a superior performance through a combination of its high sensitivity (up to 104 A W-1) and EQE value (up to 105), as well as ultrafast (memory storage.Nonpolar a-axial GaN nanowire (NW) was first used to construct the MSM (metal-semiconductor-metal) symmetrical Schottky contact device for application as visible-blind ultraviolet (UV) detector. Without any surface or composition modifications, the fabricated device demonstrated a superior performance through a combination of its high sensitivity (up to 104 A W-1) and EQE value (up to 105), as well as ultrafast (memory storage. Electronic supplementary information (ESI) available: Details of the EDS and SAED data, supplementary results of the UV detector, and the discussion of the transport properties of the MSM Schottky contact devices. See DOI: 10.1039/c4nr03581j

  14. A new 4π(LS)-γ coincidence counter at NCBJ RC POLATOM with TDCR detector in the beta channel.

    Science.gov (United States)

    Ziemek, T; Jęczmieniowski, A; Cacko, D; Broda, R; Lech, E

    2016-03-01

    A new 4π(LS)-γ coincidence system (TDCRG) was built at the NCBJ RC POLATOM. The counter consists of a TDCR detector in the beta channel and scintillation detector with NaI(Tl) crystal in the gamma channel. The system is equipped with a digital board with FPGA, which records and analyses coincidences in the TDCR detector and coincidences between the beta and gamma channels. The characteristics of the system and a scheme of the FPGA implementation with behavioral simulation are given. The TDCRG counter was validated by activity measurements on (14)C and (60)Co solutions standardized in RC POLATOM using previously validated methods. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Development and application of a luminol-based nitrogen dioxide detector

    International Nuclear Information System (INIS)

    Wendel, G.J.

    1985-01-01

    An instrument for the continuous measurement of nitrogen dioxide (NO 2 ) at all atmospheric concentration ranges and conditions was developed. The detector is based on the chemiluminescent reaction between 5-amino-2,3-dihydro-1,4-phthalazinedione (luminol) and NO 2 in alkaline aqueous solution. Development included the optimization of the cell design and the solution composition. Sodium sulfite (Na 2 SO 3 ) and methanol (CH 3 OH) were added to the solution to improve sensitivity and specificity. The detector was favorably compared to two different instruments measuring NO 2 by NO + O 3 chemiluminescent and by a tunable diode laser absorption spectrometry system. The detector has demonstrated a detection limit of 30 parts-per-trillion by volume (ppt) and a frequency response of 0.3 Hz. The instrument was operated for two one-month periods on Bermuda. The purpose was to study air masses from the East Coast of the United States after transport over the ocean. Average daily values were 400 ppt with values as low as 100 ppt measured. Other field experiments involved monitoring of NO 2 in ambient air in the range of 1 to 60 parts-per-billion by volume

  16. Subsolidus Phase Relations of the CaO-WO3-CuO System at 800 °C in Air

    DEFF Research Database (Denmark)

    Grivel, J. -C.

    2012-01-01

    The subsolidus phase relations of the CaO-WO3-CuO system were investigated in air. The samples were equilibrated at 800 degrees C. Under these conditions, five binary oxide phases are stable: Ca2CuO3, Cu3WO6, CuWO4, CaWO4 and Ca3WO6. The pseudo-ternary section is characterised by 6 three...

  17. The WUW ML bundle detector A flow through detector for alpha-emitters

    CERN Document Server

    Wenzel, U; Lochny, M

    1999-01-01

    Using conventional laboratory ware, we designed and manufactured a flow through cell for monitoring alpha-bearing solutions. The cell consists of a bundle of thermoplastic, transparent tubes coated with a thin layer of the meltable scintillator MELTILEX sup T sup M at the inner surface. With appropriate energy windows set, the detector can suppress beta-particles to a great extent due to its geometrical dimensions. For pure alpha-solutions, the detection limits are 5 Bq/ml, for composite nuclide mixtures, the detector is capable to monitor the decontamination of medium active waste (<=10 sup 7 Bq/ml) down to 100 Bq alpha/g solution. At a throughput of 1 ml/s, the pressure build-up amounts to approx 2 bar. We have developed a quality control program to ensure the regularity of the individual bundle loops.

  18. Separation of hadronic W and Z decays in the CLIC_ILD and the CLICdet detector models at 1.4 and 3TeV

    CERN Document Server

    AUTHOR|(SzGeCERN)793139; Roloff, Philipp Gerhard; Strom, Lars Rickard; Weber, Matthias Artur

    2017-01-01

    A study of the W and Z separation was performed for the CLIC_ILD and the CLICdet detector models for the proposed Compact Linear Collider (CLIC). Comparisons were done for fully-hadronic WW and ZZ events at the collision energies of 1.4 and 3 TeV. Particle flow objects are reconstructed using a full simulation of the events including relevant beam-induced background processes. Several different collections of particles, with varying level of background suppression, were compared for each of the detector models and optimal jet clustering parameters were found in each case, resulting in the best separation of the W and Z mass peaks. The CLICdet detector model performs similar to CLIC_ILD with an achieved jet mass separation of around 1.6 $\\sigma$ at 1.4 TeV and 1.3 $\\sigma$ at 3 TeV. For both detector models we achieve a better separation at 1.4 TeV when comparing dijet masses rather than large-R jet masses. At 3 TeV jets with a radius around R=0.5 perform similarly well as dijets.

  19. Noninvasive evaluation of cerebral arteriovenous malformations by 4D-CT angiography using 320-detector row CT

    International Nuclear Information System (INIS)

    Tajiri, H.; Jin, L.; Tsukiyama, M.; Suzuki, Y.; Sekine, S.; Shimizu, T.; Ohiwa, T.

    2012-01-01

    Full text: Objective: Four-dimensional computed tomography angiography (4D-CTA) is a new and promising technique in the diagnosis of patients with cerebral arteriovenous malformations (AVMs). The purpose of this retrospective study was to investigate the utility of 4D-CTA using whole-brain 320-detector row CT for assessing cerebral AVMs compared with conventional angiography (CA). Materials and methods: Participants included patients admitted to our institution from November 2010 to March 2012 due to cerebral AVMs who underwent both 4D-CTA and CA within 14 days. The diagnosis of AVM was finally confirmed by CA. Two readers reviewed 4D-CTA and CA under consensus regarding AVM detection rate and each component of the AVM (feeders, nidi, drainers) using a four-point grading scale (excellent=3, good=2, fair=1, poor=0), and the Spetzler-Martin (S-M) grade. Results: During the study period, 11 patients met the inclusion criteria. The average score for feeders, nidi, and drainers was 2.0, 2.3, and 2.5 in 4D-CTA and 2.4, 2.6, and 2.7 in CA, respectively. The average S-M grade score was 2.0 in all patients. There were no statistically significant differences between the two modalities (P<.005). Conclusion: 4D-CTA using 320-detector row CT is a very reliable method and offers diagnostic performance equivalent to CA for detecting and predicting S-M classification of cerebral AVMs.

  20. GEANT4 simulation diagram showing the architecture of the ATLAS test line: the detectors are positioned to receive the beam from the SPS. A muon particle which enters the magnet and crosses all detectors is shown (blue line).

    CERN Multimedia

    2004-01-01

    GEANT4 simulation diagram showing the architecture of the ATLAS test line: the detectors are positioned to receive the beam from the SPS. A muon particle which enters the magnet and crosses all detectors is shown (blue line).

  1. The IMB proton decay detector

    International Nuclear Information System (INIS)

    Svoboda, R.C.; Gajewski, W.; Kropp, W.R.; Reines, F.; Schultz, J.; Smith, D.W.; Sobel, H.; Wuest, C.; Bionta, R.M.; Cortez, B.G.; Errede, S.; Foster, G.W.; Greenberg, J.; Park, H.S.; Shumard, E.; Sinclair, D.; Stone, J.L.; Sulak, L.R.; Velde, J.C. van der; Goldhaber, M.; Blewitt, G.; Lehmann, E.; LoSecco, J.M.; Bratton, C.B.; Learned, J.; Svoboda, R.; Jones, T.W.; Ramana Murthy, P.V.

    1983-01-01

    A description is given of the Irvine-Michigan-Brookhaven proton decay detector which is nearing completion in a salt mine in Cleveland, Ohio, U.S.A. The detector is a water Cerenkov one with a fiducial volume of 4,000 tons and a threshold of 24 MeV. Initial results indicate that the detector is working according to specification and has a high potential for deep underground cosmic ray applications. I will give a brief account of the IMB detector construction and operation and also its present status and possible cosmic ray applications. (orig.)

  2. Research ampersand development of a helium-4 based solar neutrino detector

    International Nuclear Information System (INIS)

    Lanou, R.E.; Maris, H.J.; Seidel, G.M.

    1989-12-01

    This Progress Report covers the first six months of our May 1989 Continuation Grant. The purpose of the project is to develop and test a new detection technique for neutrinos using 4 He in the superfluid state. Based upon the expected test results it should be possible to design a practical detector leading to the ultimate goal of detecting low energy solar neutrinos. During the last six months the construction phase has moved ahead substantially. Among the areas of progress discussed in the report are: the construction of the cryostat and dilution refrigerators; the gas handling systems; computer system design; tests for radioactivity of construction materials and roton pulse simulation by computer. 5 figs

  3. Strengthening mechanisms in Ti-6Al-4V/TiC composites

    International Nuclear Information System (INIS)

    Johnson, A.J. Wagoner; Kumar, K.S.; Briant, C.L.

    2004-01-01

    In this study, the compressive behavior of Ti-6Al-4V/TiC composites considered for ballistic applications was examined at strain rates of 0.1, 1.0, and 10 s-1. As little as 1 vol% of particulate TiC provided nearly a 25% increase in strength in Ti-6Al-4V/TiC composites over that of the monolithic Ti-6Al-4V, while subsequent additions of TiC did not provide proportional benefit. The mechanisms responsible for such a significant increase in strength were investigated for the first time in this study. Microscopy (optical, SEM, TEM) aided in identifying the possible strengthening mechanisms that are typically important to the strength of metal matrix composites. These mechanisms include grain size and subgrain size refinement and an increase in dislocation density, all of which can occur during processing. Two other important mechanisms are thermal mismatch strains and load transfer from the matrix to the particle; the contribution of these mechanisms to the strength of the composite was evaluated using the Eshelby approach. A quantitative comparison of the mechanisms listed clearly showed that none of them was responsible for the large increase in strength with only 1vol%TiC in Ti-6Al-4V. The results from this study show for the first time that carbon in solution is, by far, the most potent strengthening mechanism in the Ti-6Al-4V/TiC particulate composites

  4. The pin pixel detector--neutron imaging

    CERN Document Server

    Bateman, J E; Derbyshire, G E; Duxbury, D M; Marsh, A S; Rhodes, N J; Schooneveld, E M; Simmons, J E; Stephenson, R

    2002-01-01

    The development and testing of a neutron gas pixel detector intended for application in neutron diffraction studies is reported. Using standard electrical connector pins as point anodes, the detector is based on a commercial 100 pin connector block. A prototype detector of aperture 25.4 mmx25.4 mm has been fabricated, giving a pixel size of 2.54 mm which matches well to the spatial resolution typically required in a neutron diffractometer. A 2-Dimensional resistive divide readout system has been adapted to permit the imaging properties of the detector to be explored in advance of true pixel readout electronics. The timing properties of the device match well to the requirements of the ISIS-pulsed neutron source.

  5. Large diameter lithium compensated silicon detectors for the NASA Advanced Composition Explorer (ACE) mission

    International Nuclear Information System (INIS)

    Allbritton, G.L.; Andersen, H.; Barnes, A.

    1996-01-01

    Fabrication of the 100 mm diameter, 3 mm thick lithium-compensated silicon, Si(Li), detectors for the Cosmic Ray Isotope Spectrometer (CRIS) instrument on board the ACE satellite required development of new float-zone silicon growing techniques, new Si(Li) fabrication procedures, and new particle beam testing sequences. These developments are discussed and results are presented that illustrate the advances made in realizing these CRIS Si(Li) detectors, which, when operational in the CRIS detector telescopes, will usher in a new generation of cosmic-ray isotope spectrometers

  6. CLIC Detector Concepts as described in the CDR: Differences between the GEANT4 and Engineering Models

    CERN Document Server

    Elsener, K; Schlatter, D; Siegrist, N

    2011-01-01

    The CLIC_ILD and CLIC_SiD detector concepts as used for the CDR Vol. 2 in 2011 exist both in GEANT4 simulation models and in engineering layout drawings. At this early stage of a conceptual design, there are inevitably differences between these models, which are described in this note.

  7. Characterization of laser deposited Ti6Al4V/TiC composite powders on a Ti6Al4V substrate

    CSIR Research Space (South Africa)

    Mahamood, RM

    2014-01-01

    Full Text Available This paper reports the material characterization of Ti6Al4V/TiC composite produced by laser metal deposition. The Ti6Al4V/TiC composites were deposited with a composition ratio of 50 wt.% Ti64l4V and 50 wt.% TiC. The depositions were achieved...

  8. Development of high sensitivity radon detectors

    CERN Document Server

    Takeuchi, Y; Kajita, T; Tasaka, S; Hori, H; Nemoto, M; Okazawa, H

    1999-01-01

    High sensitivity detectors for radon in air and in water have been developed. We use electrostatic collection and a PIN photodiode for these detectors. Calibration systems have been also constructed to obtain collection factors. As a result of the calibration study, the absolute humidity dependence of the radon detector for air is clearly observed in the region less than about 1.6 g/m sup 3. The calibration factors of the radon detector for air are 2.2+-0.2 (counts/day)/(mBq/m sup 3) at 0.08 g/m sup 3 and 0.86+-0.06 (counts/day)/(mBq/m sup 3) at 11 g/m sup 3. The calibration factor of the radon detector for water is 3.6+-0.5 (counts/day)/(mBq/m sup 3). The background level of the radon detector for air is 2.4+-1.3 counts/day. As a result, one standard deviation excess of the signal above the background of the radon detector for air should be possible for 1.4 mBq/m sup 3 in a one-day measurement at 0.08 g/m sup 3.

  9. The CRESST-III detector module

    Energy Technology Data Exchange (ETDEWEB)

    Wuestrich, Marc [Max-Planck-Institut f. Physik (Werner-Heisenberg-Institut) (Germany); Collaboration: CRESST-Collaboration

    2016-07-01

    The direct dark matter experiment CRESST uses scintillating calorimeters to detected WIMP induced nuclear scattering in CaWO{sub 4} single crystals. Equipped with transition edge sensors (TESs), these detectors can achieve detection thresholds well below 1 keV. The last physics run of CRESST-II proved the high potential of the experiment especially for small WIMP masses and triggered the development of a new detector module using much smaller CaWO{sub 4} main absorbers. The upcoming CRESST-III run will mainly be equipped with these newly developed modules, which combine a fully scintillating detector housing with an improved detection threshold (<100 keV). While many features of the new module were adapted from previous module designs in an improved way, also new features are implemented like instrumented sticks (iSticks) holding the crystals and optimized TES structures for phonon and light detectors. First tests above ground validated the improved performance of these detector modules and promise to explore new regions in the WIMP parameter space in the next CRESST-III run.

  10. Photon Counting Energy Dispersive Detector Arrays for X-ray Imaging.

    Science.gov (United States)

    Iwanczyk, Jan S; Nygård, Einar; Meirav, Oded; Arenson, Jerry; Barber, William C; Hartsough, Neal E; Malakhov, Nail; Wessel, Jan C

    2009-01-01

    The development of an innovative detector technology for photon-counting in X-ray imaging is reported. This new generation of detectors, based on pixellated cadmium telluride (CdTe) and cadmium zinc telluride (CZT) detector arrays electrically connected to application specific integrated circuits (ASICs) for readout, will produce fast and highly efficient photon-counting and energy-dispersive X-ray imaging. There are a number of applications that can greatly benefit from these novel imagers including mammography, planar radiography, and computed tomography (CT). Systems based on this new detector technology can provide compositional analysis of tissue through spectroscopic X-ray imaging, significantly improve overall image quality, and may significantly reduce X-ray dose to the patient. A very high X-ray flux is utilized in many of these applications. For example, CT scanners can produce ~100 Mphotons/mm(2)/s in the unattenuated beam. High flux is required in order to collect sufficient photon statistics in the measurement of the transmitted flux (attenuated beam) during the very short time frame of a CT scan. This high count rate combined with a need for high detection efficiency requires the development of detector structures that can provide a response signal much faster than the transit time of carriers over the whole detector thickness. We have developed CdTe and CZT detector array structures which are 3 mm thick with 16×16 pixels and a 1 mm pixel pitch. These structures, in the two different implementations presented here, utilize either a small pixel effect or a drift phenomenon. An energy resolution of 4.75% at 122 keV has been obtained with a 30 ns peaking time using discrete electronics and a (57)Co source. An output rate of 6×10(6) counts per second per individual pixel has been obtained with our ASIC readout electronics and a clinical CT X-ray tube. Additionally, the first clinical CT images, taken with several of our prototype photon-counting and

  11. Preparation of Shape-Controlled Graphene/Co3O4 Composites for Supercapacitors

    Science.gov (United States)

    Chen, Jun; Chen, Ningna; Feng, Xiaomiao; Hou, Wenhua

    2016-09-01

    Graphene/Co3O4 nanocomposites with different morphologies were fabricated by hydrothermal method. The morphology of nanocomposites was characterized by scanning electron microscopy. These composites could be used as the electrode materials for supercapacitors. The eletrochemical behavior of the composite was tested by cyclic voltammetry and galvanostatic charge-discharge measurements in 1.0 mol/L KOH solution. The results showed that the graphene/Co3O4 nanopetal composite exhibited excellent electrochemical performance. The specific capacitance value could reach up to 714 F/g at a scan rate of 2 mV/s. Besides, the capacitance of the graphene/Co3O4 nanopetal composite was 841 F/g at a current density of 0.1 A/g. After galvanostatic charge-discharge 1000 laps at the current density of 0.4 A/g, the specific capacitance could keep 96.7% of original capacitive value, demonstrating its good cycling stability.

  12. Neutrino induced events in the MINOS detectors

    International Nuclear Information System (INIS)

    Litchfield, Reuben Phillip

    2008-01-01

    The MINOS experiment is designed to study neutrino oscillations. It uses an accelerator generated beam of neutrinos and two detectors, the smaller at a distance of 1km and the larger at 735 km. By comparing the spectrum and flavour composition of the beam at the two detectors precise determinations of the oscillation parameters are possible. This thesis concentrates on the analysis of data from the larger Far Detector. By studying the spectrum of neutral current events it is possible to look for evidence of non-interacting 'sterile' neutrinos. The thesis describes how events are selected for this analysis, and a method for discriminating between charged current and neutral current events. The systematic uncertainties resulting from these cuts are evaluated. Several techniques for using Near Detector data to eliminate systematic uncertainties in the predicted Far Detector spectrum are compared. An oscillation analysis, based on the first year of MINOS data, uses the selected events to make a measurement of f s , the fraction of unseen neutrinos that are sterile. The measured value is f s = 0.07 +0.32 at 68%C.L., and is consistent with the standard three-neutrino picture, which has no sterile neutrino

  13. The pin pixel detector--X-ray imaging

    CERN Document Server

    Bateman, J E; Derbyshire, G E; Duxbury, D M; Marsh, A S; Simmons, J E; Stephenson, R

    2002-01-01

    The development and testing of a soft X-ray gas pixel detector, which uses connector pins for the anodes is reported. Based on a commercial 100 pin connector block, a prototype detector of aperture 25.4 mm centre dot 25.4 mm can be economically fabricated. The individual pin anodes all show the expected characteristics of small gas detectors capable of counting rates reaching 1 MHz per pin. A 2-dimensional resistive divide readout system has been developed to permit the imaging properties of the detector to be explored in advance of true pixel readout electronics.

  14. Analysis of the scintillation mechanism in a pressurized 4He fast neutron detector using pulse shape fitting

    Directory of Open Access Journals (Sweden)

    R.P. Kelley

    2015-03-01

    Full Text Available An empirical investigation of the scintillation mechanism in a pressurized 4He gas fast neutron detector was conducted using pulse shape fitting. Scintillation signals from neutron interactions were measured and averaged to produce a single generic neutron pulse shape from both a 252Cf spontaneous fission source and a (d,d neutron generator. An expression for light output over time was then developed by treating the decay of helium excited states in the same manner as the decay of radioactive isotopes. This pulse shape expression was fitted to the measured neutron pulse shape using a least-squares optimization algorithm, allowing an empirical analysis of the mechanism of scintillation inside the 4He detector. A further understanding of this mechanism in the 4He detector will advance the use of this system as a neutron spectrometer. For 252Cf neutrons, the triplet and singlet time constants were found to be 970 ns and 686 ns, respectively. For neutrons from the (d,d generator, the time constants were found to be 884 ns and 636 ns. Differences were noted in the magnitude of these parameters compared to previously published data, however the general relationships were noted to be the same and checked with expected trends from theory. Of the excited helium states produced from a 252Cf neutron interaction, 76% were found to be born as triplet states, similar to the result from the neutron generator of 71%. The two sources yielded similar pulse shapes despite having very different neutron energy spectra, validating the robustness of the fits across various neutron energies.

  15. Nucleon and composite-particle production in spallation reactions studied with the multi-purpose detector NESSI

    International Nuclear Information System (INIS)

    Herbach, C.M.; Hilscher, D.; Jahnke, U.; Tishchenko, V.G.; Galin, J.; Lott, B.; Letourneau, A.; Peghaire, A.; Filges, D.; Goldenbaum, F.; Nuenighoff, K.; Schaal, H.; Sterzenbach, G.; Wohlmuther, M.; Pienkowski, L.; Kostecke, D.; Schroeder, W.U.; Toke, J.

    2003-01-01

    NESSI, a 4π-detector for neutrons and charged particles, was used in studies of proton-induced spallation reactions at the COSY facility. Due to the high detection efficiency of NESSI for particles evaporated from excited nuclei, measured particle multiplicities provide event-by-event information on the nuclear excitation energy. Data obtained for proton-induced reactions on thin targets ranging from Al to U and proton energies from 0.8 to 2.5 GeV are compared with model predictions. (orig.)

  16. Detector simulation needs for detector designers

    International Nuclear Information System (INIS)

    Hanson, G.G.

    1987-11-01

    Computer simulation of the components of SSC detectors and of the complete detectors will be very important for the designs of the detectors. The ratio of events from interesting physics to events from background processes is very low, so detailed understanding of detector response to the backgrounds is needed. Any large detector for the SSC will be very complex and expensive and every effort must be made to design detectors which will have excellent performance and will not have to undergo major rebuilding. Some areas in which computer simulation is particularly needed are pattern recognition in tracking detectors and development of shower simulation code which can be trusted as an aid in the design and optimization of calorimeters, including their electron identification performance. Existing codes require too much computer time to be practical and need to be compared with test beam data at energies of several hundred GeV. Computer simulation of the processing of the data, including electronics response to the signals from the detector components, processing of the data by microprocessors on the detector, the trigger, and data acquisition will be required. In this report we discuss the detector simulation needs for detector designers

  17. Fabrication, characterization and simulation of 4H-SiC Schottky diode alpha particle detectors for pyroprocessing actinide monitoring

    Science.gov (United States)

    Garcia, Timothy Richard

    Pyroprocessing is a method of using high-temperature molten salts and electric fields to separate and collect fuel isotopes of used nuclear fuel. It has been has been tested in the U.S. at Idaho National Laboratory as a key step in closing the nuclear fuel cycle. One technical problem with the pyroprocessing method is a lack of knowledge regarding the actinide concentrations in the salt bath during operation, since on-line techniques for measuring these concentrations are not presently available. 4H-SiC Schottky diode detectors can potentially fulfill this need. Such detectors would operate in contact with the molten salt, and measure concentrations via alpha-particle spectroscopy. This work seeks to fabricate and characterize 4H-SiC Schottky diode detectors at high temperature, model the alpha particle spectrum expected in a molten salt, and model the operation of the detectors to confirm the physics of operation is as expected. In this work, 4H-SiC Schottky diode detectors were fabricated at OSU Nanotech West. After fabrication, these detectors were characterized using both I-V curves and Am-241 alpha-particle energy spectra. All measurements were made as a function of temperature, from room temperature up to 500°C. The average energy required to create an electron-hole pair was observed to decrease with an increase of temperature, due to a decrease of both the 4H-SiC bandgap and non-linear energy loss terms. Furthermore, the FWHM of the spectra was observed to be dependent on the leakage current at a certain temperature, and not dependent on the temperature itself. Secondly, the alpha particle energy spectrum in the pyroprocessing environment was modeled using SRIM. The molten salt was modeled in 3 different geometries, with or without a protective cover material on top of the detector. Due to the loss of alpha-particle energy in the molten salt itself, a high-energy alpha emitter may completely cover the spectrum from a lower-energy alpha emitter. Each of the

  18. 4th International Conference on New Photo-Detectors

    CERN Document Server

    2016-01-01

    The purpose of this Conference is to discuss new ideas and recent developments in photo-detectors and their applications in various fields: high energy physics, neutrino physics, particle and astroparticle physics, nuclear physics, nuclear medicine and industry. The main topics of the Conference relate to APD, SiPM, PMT, Hybrid PMT, MCP-PMT, and electronics: front-end and readout of large systems.

  19. Onboard autonomous mineral detectors for Mars rovers

    Science.gov (United States)

    Gilmore, M. S.; Bornstein, B.; Castano, R.; Merrill, M.; Greenwood, J.

    2005-12-01

    Mars rovers and orbiters currently collect far more data than can be downlinked to Earth, which reduces mission science return; this problem will be exacerbated by future rovers of enhanced capabilities and lifetimes. We are developing onboard intelligence sufficient to extract geologically meaningful data from spectrometer measurements of soil and rock samples, and thus to guide the selection, measurement and return of these data from significant targets at Mars. Here we report on techniques to construct mineral detectors capable of running on current and future rover and orbital hardware. We focus on carbonate and sulfate minerals which are of particular geologic importance because they can signal the presence of water and possibly life. Sulfates have also been discovered at the Eagle and Endurance craters in Meridiani Planum by the Mars Exploration Rover (MER) Opportunity and at other regions on Mars by the OMEGA instrument aboard Mars Express. We have developed highly accurate artificial neural network (ANN) and Support Vector Machine (SVM) based detectors capable of identifying calcite (CaCO3) and jarosite (KFe3(SO4)2(OH)6) in the visible/NIR (350-2500 nm) spectra of both laboratory specimens and rocks in Mars analogue field environments. To train the detectors, we used a generative model to create 1000s of linear mixtures of library end-member spectra in geologically realistic percentages. We have also augmented the model to include nonlinear mixing based on Hapke's models of bidirectional reflectance spectroscopy. Both detectors perform well on the spectra of real rocks that contain intimate mixtures of minerals, rocks in natural field environments, calcite covered by Mars analogue dust, and AVIRIS hyperspectral cubes. We will discuss the comparison of ANN and SVM classifiers for this task, technical challenges (weathering rinds, atmospheric compositions, and computational complexity), and plans for integration of these detectors into both the Coupled Layer

  20. Ionic conductivity and the formation of cubic CaH2 in the LiBH4-Ca(BH4)2 composite

    DEFF Research Database (Denmark)

    Sveinbjörnsson, Dadi Þorsteinn; Blanchard, Didier; Mýrdal, Jón Steinar Garðarsson

    2014-01-01

    LiBH4–Ca(BH4)2 composites were prepared by ball milling. Their crystal structures and phase composition were investigated using synchrotron X-ray diffraction and Rietveld refinement, and their ionic conductivity was measured using impedance spectroscopy. The materials were found to form a physical...... treatment. Concurrent formation of elemental boron may also occur. The ionic conductivity of the composites was measured using impedance spectroscopy, and was found to be lower than that of ball milled LiBH4. Electronic band structure calculations indicate that cubic CaH2 with hydrogen defects...... is electronically conducting. Its formation along with the possible precipitation of boron therefore has an effect on the measured conductivity of the LiBH4–Ca(BH4)2 composites and may increase the risk of an internal short-circuit in the cells....

  1. From a single encapsulated detector to the spectrometer for INTEGRAL satellite: predicting the peak-to-total ratio at high γ-energies

    International Nuclear Information System (INIS)

    Kshetri, R

    2012-01-01

    In two recent papers (R. Kshetri, JINST 2012 7 P04008; ibid., P07006), a probabilistic formalism was introduced to predict the response of encapsulated type composite germanium detectors like the SPI (spectrometer for INTEGRAL satellite). Predictions for the peak-to-total and peak-to-background ratios are given at 1.3 MeV for the addback mode of operation. The application of the formalism to clover germanium detector is discussed in two separate papers (R. Kshetri, JINST 2012 7 P07008; ibid., P08015). Using the basic approach developed in those papers, for the first time we present a procedure for calculating the peak-to-total ratio of the cluster detector for γ-energies up to 8 MeV. Results are shown for both bare and suppressed detectors as well as for the single crystal and addback modes of operation. We have considered the experimental data of (i) peak-to-total ratio at 1.3 MeV, and (ii) single detector efficiency and addback factor for other energies up to 8 MeV. Using this data, an approximate method of calculating the peak-to-total ratio of other composite detectors, is shown. Experimental validation of our approach (for energies up to 8 MeV) has been confirmed considering the data of the SPI spectrometer. We have discussed about comparisons between various modes of operation and suppression cases. The present paper is the fifth in the series of papers on composite germanium detectors and for the first time discusses about the change in fold distribution and peak-to-total ratio for sophisticated detectors consisting of several modules of miniball, cluster and SPI detectors. Our work could provide a guidance in designing new composite detectors and in performing experimental studies with the existing detectors for high energy gamma-rays.

  2. From a single encapsulated detector to the spectrometer for INTEGRAL satellite: predicting the peak-to-total ratio at high γ-energies

    Science.gov (United States)

    Kshetri, R.

    2012-12-01

    In two recent papers (R. Kshetri, JINST 2012 7 P04008; ibid., P07006), a probabilistic formalism was introduced to predict the response of encapsulated type composite germanium detectors like the SPI (spectrometer for INTEGRAL satellite). Predictions for the peak-to-total and peak-to-background ratios are given at 1.3 MeV for the addback mode of operation. The application of the formalism to clover germanium detector is discussed in two separate papers (R. Kshetri, JINST 2012 7 P07008; ibid., P08015). Using the basic approach developed in those papers, for the first time we present a procedure for calculating the peak-to-total ratio of the cluster detector for γ-energies up to 8 MeV. Results are shown for both bare and suppressed detectors as well as for the single crystal and addback modes of operation. We have considered the experimental data of (i) peak-to-total ratio at 1.3 MeV, and (ii) single detector efficiency and addback factor for other energies up to 8 MeV. Using this data, an approximate method of calculating the peak-to-total ratio of other composite detectors, is shown. Experimental validation of our approach (for energies up to 8 MeV) has been confirmed considering the data of the SPI spectrometer. We have discussed about comparisons between various modes of operation and suppression cases. The present paper is the fifth in the series of papers on composite germanium detectors and for the first time discusses about the change in fold distribution and peak-to-total ratio for sophisticated detectors consisting of several modules of miniball, cluster and SPI detectors. Our work could provide a guidance in designing new composite detectors and in performing experimental studies with the existing detectors for high energy gamma-rays.

  3. Dedicated detectors for surface studies by Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Bibicu, I.; Rogalski, M.S.; Nicolescu, G.

    2001-01-01

    Moessbauer spectroscopy is a nuclear resonance method largely utilized in solid state studies. Following resonant nuclear absorption, gamma radiations, conversion X-rays, conversion or Auger electrons are emitted. By detection of gamma radiations information about the sample as a whole are obtained while by detection of electrons or X radiation one obtains data on the surface layer. Our laboratory was among the firsts to produce and use flow gas proportional detectors for surface studies by Moessbauer spectroscopy. Four types of detectors were devised: - detectors for electron detection (90% He + 10% CH 4 ); - detectors for conversion X-ray detection (90% Ar + 10% CH 4 ); - detectors for electrons or internal conversion X rays; - detectors for simultaneous detection of electrons and conversion X rays emitted from the same source. All detectors allow simultaneous Moessbauer measurements both for surface and volume for a given sample. Details of construction are presented for the four types of detectors

  4. Build Your Own Particle Detector

    CERN Document Server

    Mehlhase, Sascha; The ATLAS collaboration

    2016-01-01

    To support the outreach activities of Atlas institutes and to grab people's attention in science exhibitions and during public events, we have created both a very detailed model of the experiment built entirely out of about Lego bricks as well as an outreach programme using Lego bricks to get people to think about particle detectors and involve them into a conversation about particle physics in general. A large Lego model, consisting of about 9500 pieces, has been 'exported' to more than 55 Atlas institutes and has been used in numerous exhibitions to explain the proportion and composition of the experiment to the public. As part of 'Build Your Own Particle Detector' programme (byopd.org) we conducted more than 15 events,either involving a competition to design and build the 'best' particle detector from a random pile of pieces or to take part in the construction of one of the large models, as part of a full day outreach event. Recently we've added miniature models of all four LHC experiments, that will be us...

  5. Characterization of detectors of neutrons from B+ZnS (Ag) as an alternative to 3He detectors

    International Nuclear Information System (INIS)

    Gonzalez, Juan A.; Suarez, Maria J.; Pujol, Luis; Lorente, Alfredo; Gallego, Eduardo

    2013-01-01

    The objective of this paper is to present the progress made in the design of prototypes for dynamic detection of neutron detectors based on scintillation of B + ZnS (Ag), which can replace existing 3 He detectors for the detection of illicit traffic of radioactive material and special nuclear material. These detectors B + ZnS (Ag) can be used, together with gamma detectors, PVT and NaI (Tl) also developed in the UPM. Two neutron detectors of different shapes and sizes were characterized using two neutron sources of 241 Am + Be. Were determined depth, overall efficiency, intrinsic efficiency and limit of detection. The results of these tests allow to verify that: 1) two cylindrical detectors B + ZnS (Ag) of 5x68 cm, or 4x15x132 cm rectangular detector can replace the cylindrical detector of 5x180 cm 3 He currently employed in the arcades. 2) the dynamic detection limit obtained is less than 20000 neutrons per second, when the sample becomes 2 m to 2m/s, with a probability of having no false positive or negative of the 99.99% 3) digital electronics eliminates interference from gamma emissions samples when their dose rate in the neutron detector is 65 μSv/h in less than factor 10 - 8, and keeps its detection limit and 4) two cylindrical detectors with two moderators of different thickness, of 25 to 50 mm of high density polyethylene, allow to measure the average energy of the neutrons

  6. Operational Experience with the ATLAS Pixel Detector

    CERN Document Server

    Djama, Fares; The ATLAS collaboration

    2017-01-01

    Run 2 of the LHC collider sets new challenges to track and vertex reconstruction because of its higher energy, pileup and luminosity. The ATLAS tracking performance relies critically on the Pixel Detector. Therefore, in view of Run 2, the ATLAS collaboration has constructed the first 4-layer pixel detector in Particle Physics by installing a new pixel layer, called Insertable B-Layer (IBL). Operational experience and performance of the 4-layer Pixel Detector during Run 2 are presented.

  7. MPX Detectors as LHC Luminosity Monitor

    CERN Document Server

    Sopczak, Andre; Asbah, Nedaa; Bergmann, Benedikt; Bekhouche, Khaled; Caforio, Davide; Campbell, Michael; Heijne, Erik; Leroy, Claude; Lipniacka, Anna; Nessi, Marzio; Pospisil, Stanislav; Seifert, Frank; Solc, Jaroslav; Soueid, Paul; Suk, Michal; Turecek, Daniel; Vykydal, Zdenek

    2015-01-01

    A network of 16 Medipix-2 (MPX) silicon pixel devices was installed in the ATLAS detector cavern at CERN. It was designed to measure the composition and spectral characteristics of the radiation field in the ATLAS experiment and its surroundings. This study demonstrates that the MPX network can also be used as a self-sufficient luminosity monitoring system. The MPX detectors collect data independently of the ATLAS data-recording chain, and thus they provide independent measurements of the bunch-integrated ATLAS/LHC luminosity. In particular, the MPX detectors located close enough to the primary interaction point are used to perform van der Meer calibration scans with high precision. Results from the luminosity monitoring are presented for 2012 data taken at sqrt(s) = 8 TeV proton-proton collisions. The characteristics of the LHC luminosity reduction rate are studied and the effects of beam-beam (burn-off) and beam-gas (single bunch) interactions are evaluated. The systematic variations observed in the MPX lum...

  8. Switching a gas detector types misromegas

    International Nuclear Information System (INIS)

    Hafsi, Marwa; Gannouni, Sonia

    2010-01-01

    Micromegas is a gas enclosure made up of two stages separated by a micro grille: the first volume of gas, 2 cm is limited by cathode and the micro grille, is the space of conversion or of drift where are creating the primary electron-ion pairs. The second volume, 100 μ m limited by the micro grille and the plan of conduction (anode), is the space of amplification which with the function to amplify the electrons by phenomenon d' avalanche. The function of this type of detector rests on various physical parameters which come into play: speed of drift of the electrons in gas, space and temporal resolution, attachment The simulations allow studying these parameters to optimize the operation of the detector by choosing a good compromise, in particular with regard to the composition of gas. Two simulation programs used to understand certain physical phenomena (configuration of the field electric in the detector, properties of transport of the electrons in gas) are Garfield and Magboltz.

  9. Production and characterization of AA6061-B4C stir cast composite

    International Nuclear Information System (INIS)

    Kalaiselvan, K.; Murugan, N.; Parameswaran, Siva

    2011-01-01

    Highlights: → Stir casting of AA6061-B 4 C Composite. Color metallographic of composites → Enhanced wetting of B 4 C particles by K 2 TiF 6 flux. → Effect of B 4 C particles on mechanical properties of AA6061. -- Abstract: This work focuses on the fabrication of aluminum (6061-T6) matrix composites (AMCs) reinforced with various weight percentage of B 4 C particulates by modified stir casting route. The wettability of B 4 C particles in the matrix has been improved by adding K 2 TiF 6 flux into the melt. The microstructure and mechanical properties of the fabricated AMCs are analyzed. The optical microstructure and scanning electron microscope (SEM) images reveal the homogeneous dispersion of B 4 C particles in the matrix. The reinforcement dispersion has also been identified with X-ray diffraction (XRD). The mechanical properties like hardness and tensile strength have improved with the increase in weight percentage of B 4 C particulates in the aluminum matrix.

  10. Mechanical Properties of TC4 Matrix Composites Prepared by Laser Cladding

    Directory of Open Access Journals (Sweden)

    WANG Lin

    2017-06-01

    Full Text Available In order to improve the penetration performance of TC4, the direct laser deposition technology was used to prepare TC4 composite material. TA15+30% TiC powder, TA15+20%Cr3C2 powder and TA15+15%B4C powder were used as deposited materials for TC4 matrix. The micromorphology, change of hardness of the deposited coating and mechanical properties of the three composites were studied. The experimental results demonstrate that the TC4 matrix with the three kinds of materials can form a complete metallurgical bonding, and the strength of TC4-(TA15+TiC, TC4-(TA15+Cr3C2 and TC4-(TA15+B4C are higher than that of TC4 matrix materials, while the plasticity is slightly worse.

  11. Modeling of clover detector in addback mode

    Science.gov (United States)

    Kshetri, R.

    2012-07-01

    Based on absorption and scattering of gamma-rays, a formalism has been presented for modeling the clover germanium detector in addback mode and to predict its response for high energy γ-rays. In the present formalism, the operation of a bare clover detector could be described in terms of three quantities only. Considering an additional parameter, the formalism could be extended for suppressed clover. Using experimental data on relative single crystal efficiency and addback factor as input, the peak-to-total ratio has been calculated for three energies (Eγ = 3.401, 5.324 and 10.430 MeV) where direct measurement of peak-to-total ratio is impossible due to absence of a radioactive source having single monoenergetic gamma-ray of that energy. The experimental validation and consistency of the formalism have been shown considering data for TIGRESS clover detector. In a recent work (R. Kshetri, JINST 2012 7 P04008), we showed that for a given γ-ray energy, the formalism could be used to predict the peak-to-total ratio as a function of number of detector modules. In the present paper, we have shown that for a given composite detector (clover detector is considered here), the formalism could be used to predict the peak-to-total ratio as a function of γ-ray energy.

  12. Modeling of clover detector in addback mode

    International Nuclear Information System (INIS)

    Kshetri, R

    2012-01-01

    Based on absorption and scattering of gamma-rays, a formalism has been presented for modeling the clover germanium detector in addback mode and to predict its response for high energy γ-rays. In the present formalism, the operation of a bare clover detector could be described in terms of three quantities only. Considering an additional parameter, the formalism could be extended for suppressed clover. Using experimental data on relative single crystal efficiency and addback factor as input, the peak-to-total ratio has been calculated for three energies (E γ = 3.401, 5.324 and 10.430 MeV) where direct measurement of peak-to-total ratio is impossible due to absence of a radioactive source having single monoenergetic gamma-ray of that energy. The experimental validation and consistency of the formalism have been shown considering data for TIGRESS clover detector. In a recent work (R. Kshetri, JINST 2012 7 P04008), we showed that for a given γ-ray energy, the formalism could be used to predict the peak-to-total ratio as a function of number of detector modules. In the present paper, we have shown that for a given composite detector (clover detector is considered here), the formalism could be used to predict the peak-to-total ratio as a function of γ-ray energy.

  13. The BABAR Detector

    Energy Technology Data Exchange (ETDEWEB)

    Luth, Vera G

    2001-05-18

    BABAR, the detector for the SLAC PEP-II asymmetric e{sup +}e{sup -} B Factory operating at the {Upsilon}(4S) resonance, was designed to allow comprehensive studies of CP-violation in B-meson decays. Charged particle tracks are measured in a multi-layer silicon vertex tracker surrounded by a cylindrical wire drift chamber. Electromagentic showers from electrons and photons are detected in an array of CsI crystals located just inside the solenoidal coil of a superconducting magnet. Muons and neutral hadrons are identified by arrays of resistive plate chambers inserted into gaps in the steel flux return of the magnet. Charged hadrons are identified by dE/dx measurements in the tracking detectors and in a ring-imaging Cherenkov detector surrounding the drift chamber. The trigger, data acquisition and data-monitoring systems, VME- and network-based, are controlled by custom-designed online software. Details of the layout and performance of the detector components and their associated electronics and software are presented.

  14. nGEM fast neutron detectors for beam diagnostics

    International Nuclear Information System (INIS)

    Croci, G.; Claps, G.; Cavenago, M.; Dalla Palma, M.; Grosso, G.; Murtas, F.; Pasqualotto, R.; Perelli Cippo, E.; Pietropaolo, A.; Rebai, M.; Tardocchi, M.; Tollin, M.; Gorini, G.

    2013-01-01

    Fast neutron detectors with a sub-millimetric space resolution are required in order to qualify neutron beams in applications related to magnetically-controlled nuclear fusion plasmas and to spallation sources. A nGEM detector has been developed for the CNESM diagnostic system of the SPIDER NBI prototype for ITER and as beam monitor for fast neutrons lines at spallation sources. The nGEM is a triple GEM gaseous detector equipped with polypropylene and polyethylene layers used to convert fast neutrons into recoil protons through the elastic scattering process. This paper describes the results obtained by testing a nGEM detector at the ISIS spallation source on the VESUVIO beam line. Beam profiles (σ x =14.35 mm, σ y =15.75 mm), nGEM counting efficiency (around 10 -4 for 3 MeV n <15 MeV), detector stability (≈4.5%) and the effect of filtering the beam with different type of materials were successfully measured. The x beam profile was compared to the one measured by a single crystal diamond detector. Finally, the efficiency of the detector was simulated exploiting the GEANT4 tool

  15. Helium ion distributions in a 4 kJ plasma focus device by 1 mm-thick large-size polycarbonate detectors

    Energy Technology Data Exchange (ETDEWEB)

    Sohrabi, M., E-mail: dr_msohrabi@yahoo.com; Habibi, M.; Ramezani, V.

    2014-11-14

    Helium ion beam profile, angular and iso-ion beam distributions in 4 kJ Amirkabir plasma focus (APF) device were effectively observed by the unaided eyes and studied in single 1 mm-thick large-diameter (20 cm) polycarbonate track detectors (PCTD). The PCTDs were processed by 50 Hz–HV electrochemical etching using a large-size ECE chamber. The results show that helium ions produced in the APF device have a ring-shaped angular distribution peaked at an angle of ∼±60° with respect to the top of the anode. Some information on the helium ion energy and distributions is also provided. The method is highly effective for ion beam studies. - Highlights: • Helium iso-ion beam profile and angular distributions were studied in the 4 kJ APF device. • Large-area 1 mm-thick polycarbonate detectors were processed by 50 Hz-HV ECE. • Helium ion beam profile and distributions were observed by unaided eyes in a single detector. • Helium ion profile has ring-shaped distributions with energies lower at the ring location. • Helium iso-ion track density, diameter and energy distributions are estimated.

  16. The AGILE anticoincidence detector

    International Nuclear Information System (INIS)

    Perotti, F.; Fiorini, M.; Incorvaia, S.; Mattaini, E.; Sant'Ambrogio, E.

    2006-01-01

    AGILE is a γ-ray astrophysics space mission which will operate, starting from 2006, in the 30 MeV-50 GeV energy range with imaging capability also in the 15-45 keV energy band. In order to achieve the required detection sensitivity, all AGILE detectors are surrounded by an anticoincidence detector aimed at charged particle background rejection with an inefficiency as low as 10 -4 . In this work, the design and the structure of this anticoincidence detector are presented, as well as its performances in terms of charged particles detection inefficiency as derived from extensive calibrations performed at CERN PS

  17. Hot nuclei studies with a 4 π-Neutron detector

    International Nuclear Information System (INIS)

    Galin, J.; Crema, E.; Doubre, H.; Guerreau, D.; Jiang, D.X.; Morjean, M.; Piasecki, E.; Pouthas, J.; Saint-Laurent, F.; Sokolov, A.; Wang, X.D.; Charvet, J.L.; Frehaut, J.; Lott, B.; Magnago, C.; Patin, Y.; Gatty, B.; Jacquet, D.; Lott, B.

    1989-01-01

    When studying the behavior of hot nuclei, the challenge is twofold: how are they formed in nucleus-nucleus collisions and how do they decay Systematic studies have been undertaken at GANIL by bombarding heavy targets (Au, Th) with intermediate energy projectiles (27, 35, 44 and 77 MeV/u Ar and 32 MeV/u Kr). For such neutron rich systems the thermalized energy can be roughly evaluated simply by measuring the multiplicity of evaporated neutrons using a 4 π Gd loaded, liquid scintillator detector. The influence of the bombarding energy and projectile mass on the energy dissipation has been investigated for different exit channels and special emphasis has been put in the study of the most dissipative collisions. The thermal energy, derived by summing the energy removed by both evaporated neutrons and light charged particles is shown to saturate at E * ≅ 650 MeV in the Ar induced reactions between 27 and 77 MeV/u, in good consistency with the predictions of semi-classical Landau-Vlasov calculations

  18. Composite detector for mixed radiations based on CsI(Tl) and dispersions of small ZnSe(Te) crystals

    International Nuclear Information System (INIS)

    Ryzhikov, V.; Gal'chinetskii, L.; Katrunov, K.; Lisetskaya, E.; Gavriluk, V.; Zelenskaya, O.; Starzhynskiy, N.; Chernikov, V.

    2005-01-01

    A new large area detector of high-energy X-ray and β-radiation has been designed and studied. A composite material based on small-crystalline ZnSe(Te) was applied onto the wide surface of a light guide. An experimental specimen has been prepared, which showed β-sensitivity C β =5.5cm 2 . The spectrograms of a 90 Sr+ 90 Y β-source obtained with the specimen under study make it possible to evaluate the age of the source by the ratio of low- and high-energy regions of the spectrum. The combined detector (CD) comprises a single crystalline plate of ZnSe(Te) placed onto the output window of a scintillating transparent light guide made of CsI(Tl) in the shape of a truncated pyramid. The CsI(Tl) light guide is used to create an additional channel for detection of γ-radiation, as well as for protecting the photodiode from the penetrating radiation. It is shown that introduction of the light guide does not worsen the energy resolution characteristics of ZnSe(Te). Separate detection of α- and γ-radiation has been achieved under simultaneous excitation by 239 Pu (ZnSe(Te), R α =6%) and 241 Am (CsI(Tl), R γ =20%). The use of selective optical filters allows separation of the peaks of total absorption (p.t.a.) in the case of their superposition

  19. Evaluation of prototype silicon drift detectors

    International Nuclear Information System (INIS)

    Ellison, J.; Hall, G.; Roe, S.; Lucas, A.

    1988-01-01

    Operating characteristics of several prototypes of silicon drift detectors are investigated. Detectors are made of unpolished silicon produced by the zone melting method and characterized by n-type conductivity and specific resistance of 3.6-4.6 kOhmxcm. The detectors comprise 40 parallel bands of 200 μm width and 1 cm length separated by 50 μm intervals. Data characterizing the potential distribution near anodes under the operating bias voltage, dependences of capacities and leakage as well as the detector space resolution

  20. Searches for heavy long-lived sleptons and R-hadrons with the ATLAS detector

    Directory of Open Access Journals (Sweden)

    Mehlhase Sascha

    2013-05-01

    Full Text Available A search for long-lived particles is performed using a data sample of 4.7 fb−1 from proton-proton collisions at a centre-of-mass energy √s = 7 TeV collected by the ATLAS detector at the LHC. No excess is observed above the estimated background and lower limits, at 95% confidence level, are set on the mass of the long-lived particles in different scenarios, based on their possible interactions in the inner detector, the calorimeters and the muon spectrometer. Long-lived staus in gauge-mediated SUSY-breaking models are excluded up to a mass of 300 GeV for tan β = 5 − 20. Directly produced long-lived sleptons are excluded up to a mass of 278 GeV. R-hadrons, composites of gluino (stop, sbottom and light quarks, are excluded up to a mass of 985 GeV (683 GeV, 612 GeV when using a generic interaction model. Additionally two sets of limits on R-hadrons are obtained that are less sensitive to the interaction model for R-hadrons. One set of limits is obtained using only the inner detector and calorimeter observables, and a second set of limits is obtained based on the inner detector alone. The full paper can be found in [1].

  1. Measurement of the cosmic ray muon charge ratio with the OPERA detector

    OpenAIRE

    Mauri, N; Siol, M

    2010-01-01

    The OPERA detector at the Gran Sasso underground laboratory (LNGS) was used to measure the cosmic ray muon charge ratio Rμ = Nμ+/Nμ− in the TeV energy region. We analyzed 403069 cosmic ray muons corresponding to 113.4 days of livetime during the 2008 CNGS run. We computed separately the muon charge ratio for single and for multiple muon events in order to select different energy regions of the primary cosmic ray spectrum and to test the Rμ dependence on the primary composition. Rμ is also sho...

  2. System tests, initial operation and first data of the AMIGA muon detector for the Pierre Auger Observatory

    Energy Technology Data Exchange (ETDEWEB)

    Pontz, Michael

    2013-07-01

    Investigating the energy region between 10{sup 17} eV and 4 x 10{sup 18} eV for primary cosmic particles will lead to a deeper understanding of the origin of cosmic rays. Effects of the transition from galactic to extragalactic origin are expected to be visible in this region. The knowledge of the composition of cosmic rays strongly depends on the hadronic interaction models, which are applied in the air shower reconstruction. Directly determining the number of muons from an air shower on ground level will improve the precision of the composition measurements by reducing the dependence on the models. The Pierre Auger Observatory is facing these challenges with an upgrade of the original detector setup. A denser sub-array of water Cherenkov detectors and a dedicated muon detector (MD) array constitute the AMIGA enhancement (Auger Muon and Infill for the Ground Array). Additional fluorescence telescopes constitute HEAT (High Elevation Auger Telescopes). Seven MD modules have been installed until mid 2012 in a first hexagon at the site of the Pierre Auger Observatory in Malarguee, Argentina. The corresponding readout electronics, and 19 more of these setups, were assembled and tested in Siegen to assure correct functionality. The detectors were incorporated in the trigger structure of the original surface detector (SD) array of the Pierre Auger Observatory and are now taking data synchronously. In the framework of this thesis, system tests have been developed, a pre-unitary cell (PUC) of seven modules has been successfully operated and their trigger has been synchronised with the SD trigger. First data from the MD have been analysed and have been combined with data from the SD.

  3. Method for manufacturing nuclear radiation detector with deep diffused junction

    International Nuclear Information System (INIS)

    Hall, R.N.

    1977-01-01

    Germanium radiation detectors are manufactured by diffusing lithium into high purity p-type germanium. The diffusion is most readily accomplished from a lithium-lead-bismuth alloy at approximately 430 0 C and is monitored by a quartz half cell containing a standard composition of this alloy. Detectors having n-type cores may be constructed by converting high purity p-type germanium to n-type by a lithium diffusion and subsequently diffusing some of the lithium back out through the surface to create a deep p-n junction. Production of coaxial germanium detectors comprising deep p-n junctions by the lithium diffusion process is described

  4. Analysis of dosimetric peaks of MgB4O7:Dy (40% Teflon versus LiF:Mg,Ti TL detectors

    Directory of Open Access Journals (Sweden)

    Paluch-Ferszt Monika

    2016-03-01

    Full Text Available Magnesium tetraborate doped with dysprosium (MgB4O7:Dy is known as a good thermoluminophor for personal dosimetry of gamma ray and X-ray radiation because of its high sensitivity and close tissue equivalence. This material can be produced by different routes. The sintered pastilles of magnesium tetraborate mixed with Teflon (40% used in this work were manufactured at the Federal University of Sergipe, Department of Physics by the solid-state synthesis. Magnesium tetraborate was already used for high-dose dosimetry, exhibiting linearity for a wide range of doses. In this work, the authors examined its main characteristics prior to potential use of detectors in everyday dosimetry, comparing this material to a widely used LiF:Mg,Ti phosphor. The following tests influencing dosimetric peaks of MgB4O7:Dy were presented: (1 the shape of the glow curves, (2 annealing conditions and post-irradiation annealing and its influence for background of the detectors, (3 the choice of the heating rates at the read-out and (4 the threshold dose, that is, the lowest possible dose to be measured. Similar tests were performed with LiF:Mg,Ti detectors, produced and widely used in Poland. The results were compared and discussed.

  5. Tribomechanical behavior of B{sub 4}C{sub p} reinforced Al 359 composites

    Energy Technology Data Exchange (ETDEWEB)

    Ramasamy, Deivasigamani; Rathanasamy, Rajasekar [Kongu Engineering College, Tamil Nadu (India). Dept. of Mechanical Engineering; Subramanian, Mohan Kumar; Kaliyannan, Gobinath Velu [PAAVAI Engineering College, Tamil Nadu (India). Dept. of Mechatronics Engineering; Palaniappan, Sathish Kumar [Indian Institute of Technology, Kharagpur, West Bengal (India); Durairaj, Jayanth

    2017-03-01

    n the present investigation, the influence of B{sub 4}C{sub p} particles on the mechanical and tribological behavior of Al 359 composites has been studied. B{sub 4}C{sub p} particle reinforced Al 359 composite samples were prepared by stir casting process. Hardness, tensile strength and wear behavior of the composites were studied and compared with a control specimen. Hardness of B{sub 4}C{sub p} particles reinforced Al 359 matrix increases compared to base matrix due to the presence of the ceramic phase. Coefficient of friction considerably increases with up to 20 wt.-% addition of B{sub 4}C{sub p} in base matrix. Specimens were subjected to wear tests under different load conditions and the following five different wear mechanisms such as wear groove, abrasion, delamination, oxidation and plastic deformation were evaluated. The abrasion results prove the increase in wear resistance of B{sub 4}C{sub p} reinforced composites compared to a control specimen.

  6. Mesoporous Fe{sub 3}O{sub 4}/hydroxyapatite composite for targeted drug delivery

    Energy Technology Data Exchange (ETDEWEB)

    Gu, Lina; He, Xiaomei; Wu, Zhenyu, E-mail: zhenyuwuhn@sina.com

    2014-11-15

    Highlights: • Mesoporous Fe{sub 3}O{sub 4}/hydroxyapatite composite was synthesized by a simple, efficient and environmental friendly method. • The prepared material had a large surface area, high pore volume, and good magnetic separability. • DOX-loaded Fe{sub 3}O{sub 4}/hydroxyapatite composite exhibited surprising slow drug release behavior and pH-dependent behavior. - Abstract: In this contribution, we introduced a simple, efficient, and green method of preparing a mesoporous Fe{sub 3}O{sub 4}/hydroxyapatite (HA) composite. The as-prepared material had a large surface area, high pore volume, and good magnetic separability, which made it suitable for targeted drug delivery systems. The chemotherapeutic agent doxorubicin (DOX) was used to investigate the drug release behavior of Fe{sub 3}O{sub 4}/HA composite. The drug release profiles displayed a little burst effect and pH-dependent behavior. The release rate of DOX at pH 5.8 was larger than that at pH 7.4, which could be attributed to DOX protonation in acid medium. In addition, the released DOX concentrations remained at 0.83 and 1.39 μg/ml at pH 7.4 and 5.8, respectively, which indicated slow, steady, and safe release rates. Therefore, the as-prepared Fe{sub 3}O{sub 4}/hydroxyapatite composite could be an efficient platform for targeted anticancer drug delivery.

  7. Zr, Hf, Mo and W-containing oxide phases as pinning additives in Bi-2212 superconductor

    International Nuclear Information System (INIS)

    Makarova, M.V.; Kazin, P.E.; Tretyakov, Yu.D.; Jansen, M.; Reissner, M.; Steiner, W.

    2005-01-01

    Phase formation was investigated in Bi-Sr-Ca-Cu-M-O (M = Mo, W) systems at 850-900 deg C. It was found that Sr 2 CaMO 6 phases were chemically compatible with Bi-2212. The composites Bi-2212-Sr 2 CaMO 6 and Bi-2212-SrAO 3 (A = Zr, Hf) were obtained from a sol-gel precursor using crystallisation from the melt. The materials consisted of Bi-2212 matrix and submicron or micron grains of the corresponding dispersed phase. T c was equal or exceeded that for undoped Bi-2212, reaching T c = 97 K in the Mo-containing composite. The composites exhibited enhanced pinning in comparison with similar prepared pure Bi-2212, especially at T = 60 K. The best pinning parameters were observed for the Bi-2212-Sr 2 CaWO 6 composite

  8. Neutrino induced events in the MINOS detectors

    Energy Technology Data Exchange (ETDEWEB)

    Litchfield, Reuben Phillip [Univ. of Oxford (United Kingdom). Keble College

    2008-01-01

    The MINOS experiment is designed to study neutrino oscillations. It uses an accelerator generated beam of neutrinos and two detectors, the smaller at a distance of 1km and the larger at 735 km. By comparing the spectrum and flavour composition of the beam at the two detectors precise determinations of the oscillation parameters are possible. This thesis concentrates on the analysis of data from the larger Far Detector. By studying the spectrum of neutral current events it is possible to look for evidence of non-interacting 'sterile' neutrinos. The thesis describes how events are selected for this analysis, and a method for discriminating between charged current and neutral current events. The systematic uncertainties resulting from these cuts are evaluated. Several techniques for using Near Detector data to eliminate systematic uncertainties in the predicted Far Detector spectrum are compared. An oscillation analysis, based on the first year of MINOS data, uses the selected events to make a measurement of f{sub s}, the fraction of unseen neutrinos that are sterile. The measured value is fs = 0.07+0.32 at 68%C.L., and is consistent with the standard three-neutrino picture, which has no sterile neutrino.

  9. Measurement stand for diagnosis of semiconductor detectors based on IBM PC/XT computer (4-way spectrometric analysis of pulses)

    International Nuclear Information System (INIS)

    Gruszecki, M.

    1990-01-01

    The technical assumptions and partial realization of our technological stand for quality inspection of semiconductor detectors for ionizing radiation manufactured in the INP in Cracow are described. To increase the efficiency of the measurements simultaneous checking of 4 semiconductor chips or finished products is suggested. In order to justify this measurement technique a review of possible variants of the measurement apparatus is presented for the systems consisting of home made units. Comparative parameters for the component modules and for complete measuring systems are given. The construction and operation of data acquisition system based on IBM PC/XT are described. The system ensures simultaneous registration of pulses obtained from 4 detectors with maximal rate of up to 500 x 10 3 pulses/s. 42 refs., 6 figs., 3 tabs. (author)

  10. Bulletin of Materials Science | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Hot corrosion performance of LVOF sprayed Al2O3–40% TiO2 coating on ... Investigation of the effects of temperature and time on reduction of graphene ..... Luminescent properties of red-light-emitting phosphors CaWO4 : Eu, Li for ... Low resistivity molybdenum thin film towards the back contact of dye-sensitized solar cell.

  11. Coaxial nuclear radiation detector with deep junction and radial field gradient

    International Nuclear Information System (INIS)

    Hall, R.N.

    1979-01-01

    Germanium radiation detectors are manufactured by diffusion lithium into high purity p-type germanium. The diffusion is most readily accomplished from a lithium-lead-bismuth alloy at approximately 430 0 and is monitored by a quartz half cell containing a standard composition of this alloy. Detectors having n-type cores may be constructed by converting high purity p-type germanium to n-type by a lithium diffusion and subsequently diffusing some of the lithium back out through the surface to create a deep p-n junction. Coaxial germanium detectors comprising deep p-n junctions are produced by the lithium diffusion process

  12. Performance of the DELPHI detector

    CERN Document Server

    Abreu, P; Adye, T; Agasi, E; Ajinenko, I; Aleksan, Roy; Alekseev, G D; Alemany, R; Allport, P P; Almehed, S; Alvsvaag, S J; Amaldi, Ugo; Amato, S; Andreazza, A; Andrieux, M L; Antilogus, P; Apel, W D; Arnoud, Y; Åsman, B; Augustin, J E; Augustinus, A; Baillon, Paul; Bambade, P; Barão, F; Barate, R; Barbiellini, Guido; Bardin, Dimitri Yuri; Baroncelli, A; Bärring, O; Barrio, J A; Bartl, Walter; Bates, M J; Battaglia, Marco; Baubillier, M; Baudot, J; Becks, K H; Begalli, M; Beillière, P; Belokopytov, Yu A; Benvenuti, Alberto C; Berggren, M; Bertrand, D; Bianchi, F; Bigi, M; Bilenky, S M; Billoir, P; Bloch, D; Blume, M; Blyth, S; Bolognese, T; Bonesini, M; Bonivento, W; Booth, P S L; Borisov, G; Bosio, C; Bosworth, S; Botner, O; Bouquet, B; Bourdarios, C; Bowcock, T J V; Bozzo, M; Branchini, P; Brand, K D; Brenke, T; Brenner, R A; Bricman, C; Brillault, L; Brown, R C A; Brückman, P; Brunet, J M; Bugge, L; Buran, T; Burgsmüller, T; Buschmann, P; Buys, A; Cabrera, S; Caccia, M; Calvi, M; Camacho-Rozas, A J; Camporesi, T; Canale, V; Canepa, M; Cankocak, K; Cao, F; Carena, F; Carrilho, P; Carroll, L; Caso, Carlo; Castillo-Gimenez, M V; Cattai, A; Cavallo, F R; Cerrito, L; Chabaud, V; Charpentier, P; Chaussard, L; Chauveau, J; Checchia, P; Chelkov, G A; Chen, M; Chierici, R; Chliapnikov, P V; Chochula, P; Chorowicz, V; Chudoba, J; Cindro, V; Collins, P; Contreras, J L; Contri, R; Cortina, E; Cosme, G; Cossutti, F; Crawley, H B; Crennell, D J; Crosetti, G; Cuevas-Maestro, J; Czellar, S; Dahl-Jensen, Erik; Dahm, J; D'Almagne, B; Dam, M; Damgaard, G; Dauncey, P D; Davenport, Martyn; Da Silva, W; Defoix, C; Deghorain, A; Della Ricca, G; Delpierre, P A; Demaria, N; De Angelis, A; de Boer, Wim; De Brabandere, S; De Clercq, C; La Vaissière, C de; De Lotto, B; De Min, A; De Paula, L S; De Saint-Jean, C; Dijkstra, H; Di Ciaccio, Lucia; Djama, F; Dolbeau, J; Dönszelmann, M; Doroba, K; Dracos, M; Drees, J; Drees, K A; Dris, M; Dufour, Y; Dupont, F; Edsall, D M; Ehret, R; Eigen, G; Ekelöf, T J C; Ekspong, Gösta; Elsing, M; Engel, J P; Ershaidat, N; Erzen, B; Espirito-Santo, M C; Falaleev, V P; Falk, E; Fassouliotis, D; Feindt, Michael; Fenyuk, A; Ferrer, A; Filippas-Tassos, A; Firestone, A; Fischer, P A; Föth, H; Fokitis, E; Fontanelli, F; Formenti, F; Franek, B J; Frenkiel, P; Fries, D E C; Frodesen, A G; Frühwirth, R; Fulda-Quenzer, F; Fuster, J A; Galloni, A; Gamba, D; Gandelman, M; García, C; García, J; Gaspar, C; Gasparini, U; Gavillet, P; Gazis, E N; Gelé, D; Gerber, J P; Gerdyukov, L N; Gibbs, M; Gokieli, R; Golob, B; Gopal, Gian P; Gorn, L; Górski, M; Guz, Yu; Gracco, Valerio; Graziani, E; Grosdidier, G; Grzelak, K; Gumenyuk, S A; Gunnarsson, P; Günther, M; Guy, J; Hahn, F; Hahn, S; Hajduk, Z; Hallgren, A; Hamacher, K; Hao, W; Harris, F J; Hedberg, V; Henriques, R P; Hernández, J J; Herquet, P; Herr, H; Hessing, T L; Higón, E; Hilke, Hans Jürgen; Hill, T S; Holmgren, S O; Holt, P J; Holthuizen, D J; Hoorelbeke, S; Houlden, M A; Hrubec, Josef; Huet, K; Hultqvist, K; Jackson, J N; Jacobsson, R; Jalocha, P; Janik, R; Jarlskog, C; Jarlskog, G; Jarry, P; Jean-Marie, B; Johansson, E K; Jönsson, L B; Jönsson, P E; Joram, Christian; Juillot, P; Kaiser, M; Kapusta, F; Karafasoulis, K; Karlsson, M; Karvelas, E; Karyukhin, A N; Katsanevas, S; Katsoufis, E C; Keränen, R; Khomenko, B A; Khovanskii, N N; King, B J; Kjaer, N J; Klein, H; Klovning, A; Kluit, P M; Köne, B; Kokkinias, P; Koratzinos, M; Kourkoumelis, C; Kuznetsov, O; Kramer, P H; Krammer, Manfred; Kreuter, C; Kronkvist, I J; Krumshtein, Z; Krupinski, W; Kubinec, P; Kucewicz, W; Kurvinen, K L; Lacasta, C; Laktineh, I; Lamblot, S; Lamsa, J; Lanceri, L; Lane, D W; Langefeld, P; Lapin, V; Last, I; Laugier, J P; Lauhakangas, R; Leder, Gerhard; Ledroit, F; Lefébure, V; Legan, C K; Leitner, R; Lemoigne, Y; Lemonne, J; Lenzen, Georg; Lepeltier, V; Lesiak, T; Liko, D; Lindner, R; Lipniacka, A; Lippi, I; Lörstad, B; Loken, J G; López, J M; López-Aguera, M A; Loukas, D; Lutz, P; Lyons, L; MacNaughton, J N; Maehlum, G; Maio, A; Malychev, V; Mandl, F; Marco, J; Maréchal, B; Margoni, M; Marin, J C; Mariotti, C; Markou, A; Maron, T; Martínez-Rivero, C; Martínez-Vidal, F; Martí i García, S; Masik, J; Matorras, F; Matteuzzi, C; Matthiae, Giorgio; Mazzucato, M; McCubbin, M L; McKay, R; McNulty, R; Medbo, J; Meroni, C; Meyer, S; Meyer, W T; Michelotto, M; Migliore, E; Mirabito, L; Mitaroff, Winfried A; Mjörnmark, U; Moa, T; Møller, R; Mönig, K; Monge, M R; Morettini, P; Müller, H; Mundim, L M; Murray, J; Muryn, B; Myatt, Gerald; Naraghi, F; Navarria, Francesco Luigi; Navas, S; Nawrocki, K; Negri, P; Neumann, W; Neumeister, N; Nicolaidou, R; Nielsen, B S; Nieuwenhuizen, M; Nikolaenko, V; Niss, P; Nomerotski, A; Normand, Ainsley; Oberschulte-Beckmann, W; Obraztsov, V F; Olshevskii, A G; Onofre, A; Orava, Risto; Österberg, K; Ouraou, A; Paganini, P; Paganoni, M; Pagès, P; Palka, H; Papadopoulou, T D; Papageorgiou, K; Pape, L; Parkes, C; Parodi, F; Passeri, A; Pegoraro, M; Peralta, L; Perevozchikov, V; Pernegger, H; Perrotta, A; Petridou, C; Petrolini, A; Petrovykh, M; Phillips, H T; Piana, G; Pierre, F; Pimenta, M; Pindo, M; Plaszczynski, S; Podobrin, O; Pol, M E; Polok, G; Poropat, P; Pozdnyakov, V; Prest, M; Privitera, P; Pukhaeva, N; Pullia, Antonio; Radojicic, D; Ragazzi, S; Rahmani, H; Rames, J; Ratoff, P N; Read, A L; Reale, M; Rebecchi, P; Redaelli, N G; Regler, Meinhard; Reid, D; Renton, P B; Resvanis, L K; Richard, F; Richardson, J; Rídky, J; Rinaudo, G; Ripp, I; Romero, A; Roncagliolo, I; Ronchese, P; Roos, L; Rosenberg, E I; Rosso, E; Roudeau, Patrick; Rovelli, T; Rückstuhl, W; Ruhlmann-Kleider, V; Ruiz, A; Rybicki, K; Saarikko, H; Sacquin, Yu; Sadovskii, A; Sajot, G; Salt, J; Sánchez, J; Sannino, M; Schimmelpfennig, M; Schneider, H; Schwickerath, U; Schyns, M A E; Sciolla, G; Scuri, F; Seager, P; Sedykh, Yu; Segar, A M; Seitz, A; Sekulin, R L; Shellard, R C; Siccama, I; Siegrist, P; Simonetti, S; Simonetto, F; Sissakian, A N; Sitár, B; Skaali, T B; Smadja, G; Smirnov, N; Smirnova, O G; Smith, G R; Solovyanov, O; Sosnowski, R; Souza-Santos, D; Spiriti, E; Sponholz, P; Squarcia, S; Stanescu, C; Stapnes, Steinar; Stavitski, I; Stichelbaut, F; Stocchi, A; Strauss, J; Strub, R; Stugu, B; Szczekowski, M; Szeptycka, M; Tabarelli de Fatis, T; Tavernet, J P; Chikilev, O G; Tilquin, A; Timmermans, J; Tkatchev, L G; Todorov, T; Toet, D Z; Tomaradze, A G; Tomé, B; Tonazzo, A; Tortora, L; Tranströmer, G; Treille, D; Trischuk, W; Tristram, G; Trombini, A; Troncon, C; Tsirou, A L; Turluer, M L; Tyapkin, I A; Tyndel, M; Tzamarias, S; Überschär, B; Ullaland, O; Valenti, G; Vallazza, E; Van der Velde, C; van Apeldoorn, G W; van Dam, P; Van Doninck, W K; Van Eldik, J; Vassilopoulos, N; Vegni, G; Ventura, L; Venus, W A; Verbeure, F; Verlato, M; Vertogradov, L S; Vilanova, D; Vincent, P; Vitale, L; Vlasov, E; Vodopyanov, A S; Vrba, V; Wahlen, H; Walck, C; Weierstall, M; Weilhammer, Peter; Weiser, C; Wetherell, Alan M; Wicke, D; Wickens, J H; Wielers, M; Wilkinson, G R; Williams, W S C; Winter, M; Witek, M; Woschnagg, K; Yip, K; Zach, F; Zaitsev, A; Zalewska-Bak, A; Zalewski, Piotr; Zavrtanik, D; Zevgolatakos, E; Zimin, N I; Zito, M; Zontar, D; Zuberi, R; Zucchelli, G C; Zumerle, G; Belokopytov, Yu; Charpentier, Ph; Gavillet, Ph; Gouz, Yu; Jarlskog, Ch

    1996-01-01

    DELPHI (DEtector with Lepton, Photon and Hadron Identification) is a detector for e^+e^- physics, designed to provide high granularity over a 4\\pi solid angle, allowing an effective particle identification. It has been operating at the LEP (Large Electron-Positron) collider at CERN since 1989. This article reviews its performance.

  13. ORLANDO - Oak Ridge Large Neutrino Detector

    International Nuclear Information System (INIS)

    Bugg, W.; Cohn, H.; Efremenko, Yu.; Fazely, A.; Gabriel, T.; Kamyshkov, Yu.; Plasil, F.; Svoboda, R.

    1999-01-01

    We discuss a proposal for construction of an Oak Ridge LArge Neutrino DetectOr (ORLANDO) to search for neutrino oscillations at the Spallation Neutron Source (SNS). A 4 MW SNS is proposed to be built at the Oak Ridge National Laboratory with the first stage to be operative around 2006. It will have two target stations, which makes it possible with a single detector to perform a neutrino oscillation search at two different distances. Initial plans for the placement of the detector and the discovery potential of such a detector are discussed

  14. Comparison of Experiment and Simulation of the triple GEM-Based Fast Neutron Detector

    International Nuclear Information System (INIS)

    Wang Xiao-Dong; Luo Wen; Zhang Jun-Wei; Yang He-Run; Duan Li-Min; Lu Chen-Gui; Hu Rong-Jiang; Hu Bi-Tao; Zhang Chun-Hui; Yang Lei; Zhou Jian-Rong; An Lv-Xing

    2015-01-01

    A detector for fast neutrons based on a 10 × 10 cm"2 triple gas electron multiplier (GEM) device is developed and tested. A neutron converter, which is a high density polyethylene (HDPE) layer, is combined with the triple GEM detector cathode and placed inside the detector, in the path of the incident neutrons. The detector is tested by obtaining the energy deposition spectrum with an Am Be neutron source in the Institute of Modern Physics (IMP) at Lanzhou. In the present work we report the results of the tests and compare them with those of simulations. The transport of fast neutrons and their interactions with the different materials in the detector are simulated with the GEANT4 code, to understand the experimental results. The detector displays a clear response to the incident fast neutrons. However, an unexpected disagreement in the energy dependence of the response between the simulated and measured spectra is observed. The neutron sources used in our simulation include deuterium-tritium (DT, 14 MeV), deuterium-deuterium (DD, 2.45 MeV), and Am Be sources. The simulation results also show that among the secondary particles generated by the incident neutron, the main contributions to the total energy deposition are from recoil protons induced in hydrogen-rich HDPE or Kapton (GEM material), and activation photons induced by neutron interaction with Ar atoms. Their contributions account for 90% of the total energy deposition. In addition, the dependence of neutron deposited energy spectrum on the composition of the gas mixture is presented. (paper)

  15. Irradiation of 4H-SiC UV detectors with heavy ions

    International Nuclear Information System (INIS)

    Kalinina, E. V.; Lebedev, A. A.; Bogdanova, E.; Berenquier, B.; Ottaviani, L.; Violina, G. N.; Skuratov, V. A.

    2015-01-01

    Ultraviolet (UV) photodetectors based on Schottky barriers to 4H-SiC are formed on lightly doped n-type epitaxial layers grown by the chemical vapor deposition method on commercial substrates. The diode structures are irradiated at 25°C by 167-MeV Xe ions with a mass of 131 amu at a fluence of 6 × 10 9 cm −2 . Comparative studies of the optical and electrical properties of as-grown and irradiated structures with Schottky barriers are carried out in the temperature range 23–180°C. The specific features of changes in the photosensitivity and electrical characteristics of the detector structures are accounted for by the capture of photogenerated carriers into traps formed due to fluctuations of the conduction-band bottom and valence-band top, with subsequent thermal dissociation

  16. Charged-particle induced radiation damage of a HPGe gamma-ray detector during spaceflight

    Energy Technology Data Exchange (ETDEWEB)

    Evans, Larry G. [Computer Sciences Corporation, Science Programs, Lanham, MD 20706 (United States); Starr, Richard [The Catholic University of America, Department of Physics, Washington, DC 20064 (United States); Brueckner, Johannes [Max-Planck-Institut fuer Chemie, Mainz (Germany); Boynton, William V. [University of Arizona, Lunar and Planetary Laboratory, Tucson, AZ 85721 (United States); Bailey, S.H. [University of Arizona, Lunar and Planetary Laboratory, Tucson, AZ 85721 (United States); Trombka, J.I. [NASA Goddard Space Flight Center, Code 691, Greenbelt, MD 20771 (United States)

    1999-02-11

    The Mars Observer spacecraft was launched on September 26, 1992 with a planned arrival at Mars after an 11-month cruise. Among the scientific instruments carried on the spacecraft was a Gamma-Ray Spectrometer (GRS) experiment to measure the composition of Mars. The GRS used a passively cooled high-purity germanium detector for measurements in the 0.2-10 MeV region. The sensor was a closed-end co-axial detector, 5.5 cm diameter by 5.5 cm long, and had an efficiency along its axis of 28% at 1332 keV relative to a standard NaI(Tl) detector. The sensor was surrounded by a thin (0.5 cm) plastic charged-particle shield. This was the first planetary mission to use a cooled Ge detector. It was expected that the long duration in space of three years would cause an increase in the energy resolution of the detector due to radiation damage and could affect the expected science return of the GRS. Shortly before arrival, on August 21, 1993, contact was lost with the spacecraft following the pressurization of the propellent tank for the orbital-insertion rocket motor. During much of the cruise to Mars, the GRS was actively collecting background data. The instrument provided over 1200 h of data collection during periods of both quiescent sun and solar flares. From the charged particle interactions in the shield, the total number of cosmic ray hits on the detector could be determined. The average cosmic ray flux at the MO GRS was about 2.5 cm{sup -2} s{sup -1}. The estimated fluence of charged particles during cruise was about 10{sup 8} particles cm{sup -2} with 31% of these occurring during a single solar proton event of approximately 10 days duration. During cruise, the detector energy resolution determined from a background gamma-ray at 1312 keV degraded from 2.4 keV full-width at half-maximum shortly after launch to 6.4 keV 11 months later. This result agrees well with measurements from ground-based accelerator irradiations (at 1.5 GeV) on a similar size detector.

  17. Pyroelectric Materials for Uncooled Infrared Detectors: Processing, Properties, and Applications

    Science.gov (United States)

    Aggarwal, M. D.; Batra, A. K.; Guggilla, P.; Edwards, M. E.; Penn, B. G.; Currie, J. R., Jr.

    2010-01-01

    Uncooled pyroelectric detectors find applications in diverse and wide areas such as industrial production; automotive; aerospace applications for satellite-borne ozone sensors assembled with an infrared spectrometer; health care; space exploration; imaging systems for ships, cars, and aircraft; and military and security surveillance systems. These detectors are the prime candidates for NASA s thermal infrared detector requirements. In this Technical Memorandum, the physical phenomena underlying the operation and advantages of pyroelectric infrared detectors is introduced. A list and applications of important ferroelectrics is given, which is a subclass of pyroelectrics. The basic concepts of processing of important pyroelectrics in various forms are described: single crystal growth, ceramic processing, polymer-composites preparation, and thin- and thick-film fabrications. The present status of materials and their characteristics and detectors figures-of-merit are presented in detail. In the end, the unique techniques demonstrated for improving/enhancing the performance of pyroelectric detectors are illustrated. Emphasis is placed on recent advances and emerging technologies such as thin-film array devices and novel single crystal sensors.

  18. Accumulation of radon in the underground detector cups

    International Nuclear Information System (INIS)

    Qiu Yuanhuo.

    1985-01-01

    Theoretical calculations based on the radon migration mechanism (i. e. diffusion, convection and atmospheric pumping etc) show that the balance of radon concentration in underground detector cups buried and in surrounding soil gas requires about 0.7-10 hours. However, the equilibrium of radon with its daughter products in the cups needs about 4 hours. Therefore, it is considered that 4.5-12 hours are needed for these two processes. It takes 3-4 days for Tn to reach radioactive equilibrium with its short-lived daughter products. When thorium concentration is higher than background exposure time of the detector cups should be over 3-4 days. Using buried detector cups, field experiments give correlative results compared with those of theoretical calculations. The study is oriented both for optimizing the burial time of the detector cup and interpretation of radon anomalies detected

  19. Development of a custom on-line ultrasonic vapour analyzer and flow meter for the ATLAS inner detector, with application to Cherenkov and gaseous charged particle detectors

    Science.gov (United States)

    Alhroob, M.; Bates, R.; Battistin, M.; Berry, S.; Bitadze, A.; Bonneau, P.; Bousson, N.; Boyd, G.; Bozza, G.; Crespo-Lopez, O.; Degeorge, C.; Deterre, C.; DiGirolamo, B.; Doubek, M.; Favre, G.; Godlewski, J.; Hallewell, G.; Hasib, A.; Katunin, S.; Langevin, N.; Lombard, D.; Mathieu, M.; McMahon, S.; Nagai, K.; O'Rourke, A.; Pearson, B.; Robinson, D.; Rossi, C.; Rozanov, A.; Strauss, M.; Vacek, V.; Zwalinski, L.

    2015-03-01

    Precision sound velocity measurements can simultaneously determine binary gas composition and flow. We have developed an analyzer with custom microcontroller-based electronics, currently used in the ATLAS Detector Control System, with numerous potential applications. Three instruments monitor C3F8 and CO2 coolant leak rates into the nitrogen envelopes of the ATLAS silicon microstrip and Pixel detectors. Two further instruments will aid operation of the new thermosiphon coolant recirculator: one of these will monitor air leaks into the low pressure condenser while the other will measure return vapour flow along with C3F8/C2F6 blend composition, should blend operation be necessary to protect the ATLAS silicon tracker under increasing LHC luminosity. We describe these instruments and their electronics.

  20. PREPARATION,COMPLEX MECHANISM AND STRUCTURE MODEL OF METALLOPHTHALOC- YANINE-Fe3O4 NANOPARTICLES COMPOSITE

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    MPc-Fe3O4-nanoparticles composite(M=Co, Cu, Ni, Mn) have been prepared and the factors that influence their mean size have been studied. The mean size of the nanoparticles composite increase with the increase of complex temperature. The interaction of MPc with Fe3O4 nanoparticles has been studied. There are M-O covalent bonding and ionic bonding between MPc and Fe3O4 nanoparticles. The intensities of M-O bonding and ionic bonding are in vestigated .The complex mechanism of MPc with Fe3O4 nanoparticles have been studied. First, there are complex between MPc and all Fe3O4 nanoparticles. Then, Fe3O4 nanoparticles accumulate together to form the accumulators, MPc have the function of cohering Fe3O4 nanoparticles. A considerable number of MPc combine with Fe3O4 nanoparticles on the surface of the accumulators to form MPc-Fe3O4 nanoparticles composite. All the above proesses take place spontaneously. The structure model of MPc-Fe3O4 nanoparticles composite has also been investigated. Inside the MPc-Fe3O4 nanoparticles composite, Fe3O4 nanoparticles accumulate together without order, on the surface of the composite, MPc form molecular dispersion layer. The threshold of molecular dispersion layer are also investigated.

  1. Utah Fly's Eye detector

    Energy Technology Data Exchange (ETDEWEB)

    Baltrusaitis, R.M.; Cady, R.; Cassiday, G.L.; Cooper, R.; Elbert, J.W.; Gerhardy, P.R.; Ko, S.; Loh, E.C.; Salamon, M.; Steck, D.; Sokolsky, P.

    1985-10-15

    We report the details of the design, operation and performance of the University of Utah Fly's Eye detector which was built to record the passage of ultra-high energy cosmic rays through the atmosphere via atmospheric fluorescence. Emphasized in the presentation are (1) light production by charged particles in the atmosphere, (2) kinematics of an EAS as seen by the Fly's Eye, (3) signal to noise considerations and its impact on detector design, (4) details of detector hardware and software, (5) detector calibration, (6) techniques employed in measurement of shower longitudinal development profiles and primary particle energy, and (7) assessment of detector performance by a comparison of Monte Carlo and real data distributions. (orig.).

  2. Ultra high resolution X-ray detectors

    International Nuclear Information System (INIS)

    Hess, U.; Buehler, M.; Hentig, R. von; Hertrich, T.; Phelan, K.; Wernicke, D.; Hoehne, J.

    2001-01-01

    CSP Cryogenic Spectrometers GmbH is developing cryogenic energy dispersive X-ray spectrometers based on superconducting detector technology. Superconducting sensors exhibit at least a 10-fold improvement in energy resolution due to their low energy gap compared to conventional Si(Li) or Ge detectors. These capabilities are extremely valuable for the analysis of light elements and in general for the analysis of the low energy range of the X-ray spectrum. The spectrometer is based on a mechanical cooler needing no liquid coolants and an adiabatic demagnetization refrigerator (ADR) stage which supplies the operating temperature of below 100 mK for the superconducting sensor. Applications include surface analysis in semiconductor industry as well material analysis for material composition e.g. in ceramics or automobile industry

  3. Facile preparation and enhanced microwave absorption properties of flake carbonyl iron/Fe3O4 composite

    International Nuclear Information System (INIS)

    Min, Dandan; Zhou, Wancheng; Luo, Fa; Zhu, Dongmei

    2017-01-01

    Highlights: • Flake carbonyl iron/Fe 3 O 4 composites were prepared by surface oxidation technique. • Lower permittivity and modest permeability was obtained by the FCI/Fe 3 O 4 composites. • Enhanced absorption efficiency and broader absorption band were obtained. - Abstract: Flake carbonyl iron/Fe 3 O 4 (FCI/Fe 3 O 4 ) composites with enhanced microwave absorption properties were prepared by a direct and flexible surface oxidation technique. The phase structures, morphology, magnetic properties, frequency-dependent electromagnetic and microwave absorption properties of the composites were investigated. The measurement results showed that lower permittivity as well as modest permeability was obtained by the FCI/Fe 3 O 4 composites. The calculated microwave absorption properties indicated that enhanced absorption efficiency and broader absorption band were obtained by the FCI/Fe 3 O 4 composite comparing with the FCI composite. The absorption frequency range with reflection loss (RL) below −5 dB of FCI/Fe 3 O 4 composites at reaction time of 90 min at thickness of 1.5 mm is 13.3 GHz from 4.7 to 18 GHz, while the bandwidth of the FCI composite is only 5.9 GHz from 2.6 to 8.5 GHz at the same thickness. Thus, such absorbers could act as effective and wide broadband microwave absorbers in the GHz range.

  4. Radiation detectors

    International Nuclear Information System (INIS)

    2013-01-01

    This sixth chapter presents the operational principles of the radiation detectors; detection using photographic emulsions; thermoluminescent detectors; gas detectors; scintillation detectors; liquid scintillation detectors; detectors using semiconductor materials; calibration of detectors; Bragg-Gray theory; measurement chain and uncertainties associated to measurements

  5. Quantitative microanalysis in the analytical electronmicroscope using an HPGe-x ray detector

    International Nuclear Information System (INIS)

    Grogger, W.

    1994-01-01

    Energy dispersive x-ray spectrometry (EDX) is a routine method for determining the chemical composition of a sample in the analytical electronmicroscope. Since some years high purity germanium x-ray detectors (HPGe) are commercially available for use in EDX. This new type of detector offers some advantages over the commonly used Si (Li) detector: better energy resolution, better detector efficiency for high energy lines (> 30 keV) and better stability against exterior influences. For quantitative analysis one needs sensitivity factors (k-factors), which correlate the measured intensity to the concentration of a specific element. These k-factors can be calculated or determined experimentally. For a precise quantitative analysis of light elements measured k-factors are absolutely necessary. In this study k-factors were measured with an HPGe detector using standards. The accuracy of the k-factors was proved using some examples of practical relevance. Additionally some special features of the HPGe detector were examined, which lead to a better understanding of EDX spectrometry using an HPGe detector (escape lines, icing of the detector, artifacts). (author)

  6. A first principle approach for clover detector

    Science.gov (United States)

    Kshetri, R.

    2012-08-01

    A simple model based on probability flow arguments has been presented for understanding the clover germanium detector. Using basic concepts of absorption and scattering of gamma-rays, the operation of the clover detector has been described in terms of six probability amplitudes and a parameter. Instead of using an empirical method or simulation, this work presents the first attempt to calculate the peak-to-total and peak-to-background ratios of the clover detector using experimental data of relative single crystal efficiency and addback factor as an input. A unique feature of our approach is that these ratios could be calculated for energies where their direct measurement is impossible due to absence of a radioactive source having single monoenergetic gamma-ray of that energy. Results for four gamma-ray energies (Eγ = 1.408, 3.907, 7.029 and 10.430 MeV) have been discussed. Agreement between experimental data and analysis results has been observed. The present approach could describe clover-type detectors as well. As an example, the nine element detector has been considered. We have demonstrated that our formalism can describe both finite and infinite interactions of γ-rays with the clover crystals. The work presented in this paper follows similar philosophy as presented in a recent paper (R. Kshetri, JInst 2012 7 P04008), which deals with modeling of encapsulated type composite detectors like miniball, cluster and SPI (Spectrometer for INTEGRAL satellite).

  7. A first principle approach for clover detector

    International Nuclear Information System (INIS)

    Kshetri, R

    2012-01-01

    A simple model based on probability flow arguments has been presented for understanding the clover germanium detector. Using basic concepts of absorption and scattering of gamma-rays, the operation of the clover detector has been described in terms of six probability amplitudes and a parameter. Instead of using an empirical method or simulation, this work presents the first attempt to calculate the peak-to-total and peak-to-background ratios of the clover detector using experimental data of relative single crystal efficiency and addback factor as an input. A unique feature of our approach is that these ratios could be calculated for energies where their direct measurement is impossible due to absence of a radioactive source having single monoenergetic gamma-ray of that energy. Results for four gamma-ray energies (E γ = 1.408, 3.907, 7.029 and 10.430 MeV) have been discussed. Agreement between experimental data and analysis results has been observed. The present approach could describe clover-type detectors as well. As an example, the nine element detector has been considered. We have demonstrated that our formalism can describe both finite and infinite interactions of γ-rays with the clover crystals. The work presented in this paper follows similar philosophy as presented in a recent paper (R. Kshetri, JInst 2012 7 P04008), which deals with modeling of encapsulated type composite detectors like miniball, cluster and SPI (Spectrometer for INTEGRAL satellite).

  8. Determination of the detection efficiency of a HPGe detector by means of the MCNP 4A simulation code; Determinacion de la eficiencia de deteccion de un detector HPGe mediante el codigo de simulacion MCNP 4A

    Energy Technology Data Exchange (ETDEWEB)

    Leal, B. [Centro Regional de Estudios Nucleares, A.P. 579C, 98068 Zacatecas (Mexico)

    2004-07-01

    In the majority of the laboratories, the calibration in efficiency of the detector is carried out by means of the standard sources measurement of gamma photons that have a determined activity, or for matrices that contain a variety of radionuclides that can embrace the energy range of interest. Given the experimental importance that has the determination from the curves of efficiency to the effects of establishing the quantitative results, is appealed to the simulation of the response function of the detector used in the Regional Center of Nuclear Studies inside the energy range of 80 keV to 1400 keV varying the density of the matrix, by means of the application of the Monte Carlo code MCNP-4A. The adjustment obtained shows an acceptance grade in the range of 100 to 600 keV, with a smaller percentage discrepancy to 5%. (Author)

  9. Calorimetric low-temperature detectors on semiconductor base for the energy-resolving detection of heavy ions

    International Nuclear Information System (INIS)

    Kienlin, A. von.

    1994-01-01

    In the framework of this thesis for the first time calorimetric low-temperature detectors for the energy-resolving detection of heavy ions were developed and successfully applied. Constructed were two different detector types, which work both with a semiconductor thermistor. The temperature increasement effected by a particle incidence is read out. In the first detector type the thermistor was simutaneously used as absorber. The thickness of the germanium crystals was sufficient in order to stop the studied heavy ions completely. In the second type, a composed calorimeter, a sapphire crystal, which was glued on a germanium thermistor, served as absorber for the incident heavy ions. The working point of the calorimeter lies in the temperature range (1.2-4.2 K), which is reachable with a pumped 4 He cryostat. The temperatur increasement of the calorimeter amounts after the incidence of a single α particle about 20-30 μK and that after a heavy ion incidence up to some mK. An absolute energy resolution of 400-500 keV was reached. In nine beam times the calorimeters were irradiated by heavy ions ( 20 Ne, 40 Ar, 136 Xe, 208 Pb, 209 Bi) of different energies (3.6 MeV/nucleon< E<12.5 MeV/nucleon) elastically scattered from gold foils. In the pulse height spectra of the first detector type relatively broad, complex-structurated line shapes were observed. By systematic measurements dependences of the complex line structures on operational parameters of the detector, the detector temperature, and the position of the incident particle could be detected. Together with the results of further experiments a possible interpretation of these phenomena is presented. Contrarily to the complex line structures of the pure germanium thermistor the line shapes in the pulse height spectra, which were taken up in a composite germanium/sapphire calorimeter, are narrow and Gauss-shaped

  10. Fabrication of MgAl2O4 spinel/niobium laminar composites by plasma spraying

    International Nuclear Information System (INIS)

    Boncoeur, M.; Lochet, N.; Miomandre, F.; Schnedecker, G.

    1994-01-01

    The feasibility of plasma spray manufacturing of laminar ceramic matrix composites made of alternate thin layers of a ceramic oxide and a metal is demonstrated with a composite made of 7 layers, each 0.2 mm thick, of MgAl 2 O 4 spinel and niobium. Microstructure and mechanical characteristics have been studied with both as-sprayed and heat-treated under vacuum at 1400 C conditions. It is shown that the as-sprayed composite is brittle but becomes pseudo-plastic after heat treatment. These laminar composites are very attractive for the manufacturing of large surface, few millimeter thick components. (from authors). 4 figs., 4 refs

  11. Development of floating strip micromegas detectors

    Energy Technology Data Exchange (ETDEWEB)

    Bortfeldt, Jonathan

    2014-04-28

    Micromegas are high-rate capable, high-resolution micro-pattern gaseous detectors. Square meter sized resistive strip Micromegas are foreseen as replacement of the currently used precision tracking detectors in the Small Wheel, which is part of the forward region of the ATLAS muon spectrometer. The replacement is necessary to ensure tracking and triggering performance of the muon spectrometer after the luminosity increase of the Large Hadron Collider beyond its design value of 10{sup 34} cm{sup -2}s{sup -1} around 2020. In this thesis a novel discharge tolerant floating strip Micromegas detector is presented and described. By individually powering copper anode strips, the effects of a discharge are confined to a small region of the detector. This reduces the impact of discharges on the efficiency by three orders of magnitude, compared to a standard Micromegas. The physics of the detector is studied and discussed in detail. Several detectors are developed: A 6.4 x 6.4 cm{sup 2} floating strip Micromegas with exchangeable SMD capacitors and resistors allows for an optimization of the floating strip principle. The discharge behavior is investigated on this device in depth. The microscopic structure of discharges is quantitatively explained by a detailed detector simulation. A 48 x 50 cm{sup 2} floating strip Micromegas is studied in high energy pion beams. Its homogeneity with respect to pulse height, efficiency and spatial resolution is investigated. The good performance in high-rate background environments is demonstrated in cosmic muon tracking measurements with a 6.4 x 6.4 cm{sup 2} floating strip Micromegas under lateral irradiation with 550 kHz 20 MeV proton beams. A floating strip Micromegas doublet with low material budget is developed for ion tracking without limitations from multiple scattering in imaging applications during medical ion therapy. Highly efficient tracking of 20 MeV protons at particle rates of 550 kHz is possible. The reconstruction of the

  12. Development of floating strip micromegas detectors

    International Nuclear Information System (INIS)

    Bortfeldt, Jonathan

    2014-01-01

    Micromegas are high-rate capable, high-resolution micro-pattern gaseous detectors. Square meter sized resistive strip Micromegas are foreseen as replacement of the currently used precision tracking detectors in the Small Wheel, which is part of the forward region of the ATLAS muon spectrometer. The replacement is necessary to ensure tracking and triggering performance of the muon spectrometer after the luminosity increase of the Large Hadron Collider beyond its design value of 10 34 cm -2 s -1 around 2020. In this thesis a novel discharge tolerant floating strip Micromegas detector is presented and described. By individually powering copper anode strips, the effects of a discharge are confined to a small region of the detector. This reduces the impact of discharges on the efficiency by three orders of magnitude, compared to a standard Micromegas. The physics of the detector is studied and discussed in detail. Several detectors are developed: A 6.4 x 6.4 cm 2 floating strip Micromegas with exchangeable SMD capacitors and resistors allows for an optimization of the floating strip principle. The discharge behavior is investigated on this device in depth. The microscopic structure of discharges is quantitatively explained by a detailed detector simulation. A 48 x 50 cm 2 floating strip Micromegas is studied in high energy pion beams. Its homogeneity with respect to pulse height, efficiency and spatial resolution is investigated. The good performance in high-rate background environments is demonstrated in cosmic muon tracking measurements with a 6.4 x 6.4 cm 2 floating strip Micromegas under lateral irradiation with 550 kHz 20 MeV proton beams. A floating strip Micromegas doublet with low material budget is developed for ion tracking without limitations from multiple scattering in imaging applications during medical ion therapy. Highly efficient tracking of 20 MeV protons at particle rates of 550 kHz is possible. The reconstruction of the track inclination in a single

  13. Pulse height model for deuterated scintillation detectors

    International Nuclear Information System (INIS)

    Wang, Haitang; Enqvist, Andreas

    2015-01-01

    An analytical model of light pulse height distribution for finite deuterated scintillation detectors is created using the impulse approximation. Particularly, the energy distribution of a scattered neutron is calculated based on an existing collision probability scheme for general cylindrical shaped detectors considering double differential cross-sections. The light pulse height distribution is analytically and numerically calculated by convoluting collision sequences with the light output function for an EJ-315 detector from our measurements completed at Ohio University. The model provides a good description of collision histories capturing transferred neutron energy in deuterium-based scintillation materials. The resulting light pulse height distribution details pulse compositions and their corresponding contributions. It shows that probabilities of neutron collision with carbon and deuterium nuclei are comparable, however the light pulse amplitude due to collisions with carbon nuclei is small and mainly located at the lower region of the light pulse distribution axis. The model can explore those neutron interaction events that generate pulses near or below a threshold that would be imposed in measurements. A comparison is made between the light pulse height distributions given by the analytical model and measurements. It reveals a significant probability of a neutron generating a small light pulse due to collisions with carbon nuclei when compared to larger light pulse generated by collisions involving deuterium nuclei. This model is beneficial to understand responses of scintillation materials and pulse compositions, as well as nuclei information extraction from recorded pulses.

  14. MPX detectors as LHC luminosity monitor

    Energy Technology Data Exchange (ETDEWEB)

    Sopczak, Andre; Ali, Babar; Bergmann, Benedikt; Caforio, Davide; Heijne, Erik; Pospisil, Stanislav; Seifert, Frank; Solc, Jaroslav; Suk, Michal; Turecek, Daniel [IEAP CTU in Prague (Czech Republic); Ashba, Nedaa; Leroy, Claude; Soueid, Paul [University of Montreal (Canada); Bekhouche, Khaled [Biskra University (Algeria); Campbell, Michael; Nessi, Marzio [CERN (Switzerland); Lipniacka, Anna [Bergen University (Norway)

    2016-07-01

    A network of 16 Medipix-2 (MPX) silicon pixel devices was installed in the ATLAS detector cavern at CERN. It was designed to measure the composition and spectral characteristics of the radiation field in the ATLAS experiment and its surroundings. This study demonstrates that the MPX network can also be used as a self-sufficient luminosity monitoring system. The MPX detectors collect data independently of the ATLAS data-recording chain, and thus they provide independent measurements of the bunch-integrated ATLAS/LHC luminosity. In particular, the MPX detectors located close enough to the primary interaction point are used to perform van der Meer calibration scans with high precision. Results from the luminosity monitoring are presented for 2012 data taken at √(s) =8 TeV proton-proton collisions. The characteristics of the LHC luminosity reduction rate are studied and the effects of beam-beam (burn-off) and beam-gas (single bunch) interactions are evaluated. The systematic variations observed in the MPX luminosity measurements are below 0.3% for one minute intervals.

  15. An empirical method for peak-to-total ratio computation of a gamma-ray detector

    International Nuclear Information System (INIS)

    Cesana, A.; Terrani, M.

    1989-01-01

    A simple expression for peak-to-total ratio evaluation of gamma-ray detectors in the energy range 0.3-10 MeV is proposed. The quantities one needs to know for the computation are: Detector dimensions and chemical composition, photon corss sections and an empirical energy dependent function which is valid for all the detector materials considered. This procedure seems able to produce peak-to-total values with an accuracy comparable with the most sophisticated Monte Carlo calculations. It has been tested using experimental peak-to-total values of Ge, NaI, CsI and BGO detectors but it is reasonable to suppose that it is valid for any detector material. (orig.)

  16. MUON DETECTORS: RPC

    CERN Multimedia

    P. Paolucci

    2011-01-01

    During data-taking in 2010 the RPC system behaviour was very satisfactory for both the detector and trigger performances. Most of the data analyses are now completed and many results and plots have been approved in order to be published in the muon detector paper. A very detailed analysis of the detector efficiency has been performed using 60 million muon events taken with the dedicated RPC monitor stream. The results have shown that the 96.3% of the system was working properly with an average efficiency of 95.4% at 9.35 kV in the Barrel region and 94.9% at 9.55 kV in the Endcap. Cluster size goes from 1.6 to 2.2 showing a clear and well-known correlation with the strip pitch. Average noise in the Barrel is less than 0.4 Hz/cm2 and about 98% of full system has averaged noise less then 1 Hz/cm2. A linear dependence of the noise versus the luminosity has been preliminary observed and is now under study. Detailed chamber efficiency maps have shown a few percent of chambers with a non-uniform efficiency distribu...

  17. Neutrino-4 experiment on search for sterile neutrino with multi-section model of detector

    Science.gov (United States)

    Serebrov, A.; Ivochkin, V.; Samoilov, R.; Fomin, A.; Polyushkin, A.; Zinoviev, V.; Neustroev, P.; Golovtsov, V.; Chernyj, A.; Zherebtsov, O.; Martemyanov, V.; Tarasenkov, V.; Aleshin, V.; Petelin, A.; Izhutov, A.; Tuzov, A.; Sazontov, S.; Ryazanov, D.; Gromov, M.; Afanasiev, V.; Zaytsev, M.; Chaikovskii, M.

    2017-09-01

    In order to carry out research in the field of possible existence of a sterile neutrino the laboratory based on SM-3 reactor (Dimitrovgrad, Russia) was created to search for oscillations of reactor antineutrino. The prototype of a multi-section neutrino detector with liquid scintillator volume of 350 l was installed in the middle of 2015. It is a moveable inside the passive shielding detector, which can be set at distance range from 6 to 11 meters from the reactor core. Measurements of antineutrino flux at such small distances from the reactor core are carried out with moveable detector for the first time. The measurements carried out with detector prototype demonstrated a possibility of measuring a reactor antineutrino flux in difficult conditions of cosmic background at Earth surface.

  18. PNGS-A unit 4 composite graphite valve packing program

    International Nuclear Information System (INIS)

    Meaney, F.

    1992-01-01

    During the outage of Pickering 4 for retubing and rehabilitation, a composite graphite packing program was completed on 100 conventional valves and 50 nuclear valves. This paper describes component refurbishment, related maintenance, and manpower requirements. 2 figs

  19. Precision of MPX detectors as LHC luminosity monitor

    Energy Technology Data Exchange (ETDEWEB)

    Sopczak, Andre; Ali, Babar; Benes, Petr; Bergmann, Benedikt; Biskup, Bartolomej; Caforio, Davide; Heijne, Erik; Pospisil, Stanislav; Seifert, Frank; Solc, Jaroslav; Suk, Michal; Turecek, Daniel; Vykydal, Zdenek [IEAP CTU in Prague (Czech Republic); Asbah, Nedaa; Leroy, Claude; Soueid, Paul [University of Montreal (Canada); Campbell, Michael; Nessi, Marzio [CERN (Switzerland); Kladiva, Edward [IEP SAS Kosice (Slovakia)

    2015-07-01

    A network consisting of MPX detectors based on Medipix2 silicon pixel devices were originally adapted for measuring the composition and spectral characteristics of the radiation field in the ATLAS experiment and its surroundings. We demonstrate that the MPX network, which consists of 16 MPX detectors, is a self-contained luminosity monitor system. As the MPX detectors are collecting data independently of the ATLAS data-recording chain, they provide independent measurements of the bunch-integrated ATLAS/LHC luminosity. In particular, the MPX detectors close enough to the primary interaction point are used to perform van der Meer calibration scans with good precision. Results from the luminosity monitoring are presented for 2012 data taken at √(s)=8 TeV proton-proton collisions. The characteristics of the LHC luminosity reduction are studied and the effects of beam-beam (burn-off) and beam-gas (single bunch) interactions are evaluated. The variations of the MPX luminosity measurements around the fitted curve lead to a relative uncertainty on the luminosity measurement below 0.3% for one minute time intervals.

  20. Ionization detector

    International Nuclear Information System (INIS)

    Steele, D.S.

    1987-01-01

    An ionization detector having an array of detectors has, for example, grounding pads positioned in the spaces between some detectors (data detectors) and other detectors (reference detectors). The grounding pads are kept at zero electric potential, i.e. grounded. The grounding serves to drain away electrons and thereby prevent an unwanted accumulation of charge in the spaces, and cause the electric field lines to be more perpendicular to the detectors in regions near the grounding pads. Alternatively, no empty space is provided there being additional, grounded, detectors provided between the data and reference detectors. (author)

  1. Sensitive detectors in HPLC

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    Detection of sample components in HPLC is difficult for many reasons; the key difficulty is the mobile phase which usually has properties similar to the solute. A variety of detectors have been developed for use in HPLC based on one of the above approaches; however, the search is still continuing for an ideal or universal detector. A universal detector should have the following characteristics: (1) responds to all solutes or has predictable specificity; (2) high detectability and the same predictable response; (3) fast response; (4) wide range of linearity; (5) unaffected by changes in temperature and mobile-phase flow; (6) responds independently of the mobile phase; (7) makes no contribution to extracolumn band broadening; (8) reliable and convenient to use; (9) nondestructive to the solute; (10) provides qualitative information on the detected peak. Unfortunately, no available HPLC detector possesses all these properties. 145 refs

  2. Study on response function of CdTe detector

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyunduk; Cho, Gyuseong [Department of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, Daejeon 305-701 (Korea, Republic of); Kang, Bo-Sun [Department of Radiological Science, Catholic University of Daegu, Kyoungsan, Kyoungbuk 712-702 (Korea, Republic of)], E-mail: bskang@cu.ac.kr

    2009-10-21

    So far the origin of the mechanism of light emission in the sonoluminescence has not elucidated whether it is due to blackbody radiation or bremsstrahlung. The final goal of our study is measuring X-ray energy spectrum using high-sensitivity cadmium telluride (CdTe) detector in order to obtain information for understanding sonoluminescence phenomena. However, the scope of this report is the measurement of X-ray spectrum using a high-resolution CdTe detector and determination of CdTe detector response function to obtain the corrected spectrum from measured soft X-ray source spectrum. In general, the measured spectrum was distorted by the characteristics of CdTe detector. Monte Carlo simulation code, MCNP, was used to obtain the reference response function of the CdTe detector. The X-ray spectra of {sup 57}Co, {sup 133}Ba, and {sup 241}Am were obtained by a 4x4x1.0(t) mm{sup 3} CdTe detector at room temperature.

  3. The PANDA detector at FAIR

    International Nuclear Information System (INIS)

    Bersani, Andrea

    2012-01-01

    The PANDA detector will be installed at FAIR to enterprise a long-term, wide-spectrum physics program in the strong interaction framework. The detector will be installed at the HESR accumulation ring, which will provide an anti-proton beam of unprecedented luminosity and momentum definition. The beam will interact with an internal target. The detector has been designed to allow a 4π coverage around the interaction region. Due to the relatively high energy of the beam, up to 15 GeV, PANDA will feature two magnetic spectrometers: the target spectrometer (TS), with a superconducting solenoid and covering the interaction region, and a forward spectrometer (FS), with a normal-conducting dipole and covering the small angles region. Since the physics program is wide and the requirements on the various subsystems are different, the detector has been designed to be as flexible as possible. The complete detector will be described in detail, both from the viewpoint of the proposed techniques and from the viewpoint of the expected performances. An overview of the status of various components of the detector will be presented, too.

  4. The PANDA detector at FAIR

    Science.gov (United States)

    Bersani, Andrea

    2012-10-01

    The PANDA detector will be installed at FAIR to enterprise a long-term, wide-spectrum physics program in the strong interaction framework. The detector will be installed at the HESR accumulation ring, which will provide an anti-proton beam of unprecedented luminosity and momentum definition. The beam will interact with an internal target. The detector has been designed to allow a 4π coverage around the interaction region. Due to the relatively high energy of the beam, up to 15 GeV, PANDA will feature two magnetic spectrometers: the target spectrometer (TS), with a superconducting solenoid and covering the interaction region, and a forward spectrometer (FS), with a normal-conducting dipole and covering the small angles region. Since the physics program is wide and the requirements on the various subsystems are different, the detector has been designed to be as flexible as possible. The complete detector will be described in detail, both from the viewpoint of the proposed techniques and from the viewpoint of the expected performances. An overview of the status of various components of the detector will be presented, too.

  5. Low Energy X-Ray and γ-Ray Detectors Fabricated on n-Type 4H-SiC Epitaxial Layer

    Science.gov (United States)

    Mandal, Krishna C.; Muzykov, Peter G.; Chaudhuri, Sandeep K.; Terry, J. Russell

    2013-08-01

    Schottky barrier diode (SBD) radiation detectors have been fabricated on n-type 4H-SiC epitaxial layers and evaluated for low energy x- and γ-rays detection. The detectors were found to be highly sensitive to soft x-rays in the 50 eV to few keV range and showed 2.1 % energy resolution for 59.6 keV gamma rays. The response to soft x-rays for these detectors was significantly higher than that of commercial off-the-shelf (COTS) SiC UV photodiodes. The devices have been characterized by current-voltage (I-V) measurements in the 94-700 K range, thermally stimulated current (TSC) spectroscopy, x-ray diffraction (XRD) rocking curve measurements, and defect delineating chemical etching. I-V characteristics of the detectors at 500 K showed low leakage current ( nA at 200 V) revealing a possibility of high temperature operation. The XRD rocking curve measurements revealed high quality of the epitaxial layer exhibiting a full width at half maximum (FWHM) of the rocking curve 3.6 arc sec. TSC studies in a wide range of temperature (94-550 K) revealed presence of relatively shallow levels ( 0.25 eV) in the epi bulk with a density 7×1013 cm-3 related to Al and B impurities and deeper levels located near the metal-semiconductor interface.

  6. A chemically activated graphene-encapsulated LiFePO4 composite for high-performance lithium ion batteries.

    Science.gov (United States)

    Ha, Jeonghyun; Park, Seung-Keun; Yu, Seung-Ho; Jin, Aihua; Jang, Byungchul; Bong, Sungyool; Kim, In; Sung, Yung-Eun; Piao, Yuanzhe

    2013-09-21

    A composite of modified graphene and LiFePO4 has been developed to improve the speed of charging-discharging and the cycling stability of lithium ion batteries using LiFePO4 as a cathode material. Chemically activated graphene (CA-graphene) has been successfully synthesized via activation by KOH. The as-prepared CA-graphene was mixed with LiFePO4 to prepare the composite. Microscopic observation and nitrogen sorption analysis have revealed the surface morphologies of CA-graphene and the CA-graphene/LiFePO4 composite. Electrochemical properties have also been investigated after assembling coin cells with the CA-graphene/LiFePO4 composite as a cathode active material. Interestingly, the CA-graphene/LiFePO4 composite has exhibited better electrochemical properties than the conventional graphene/LiFePO4 composite as well as bare LiFePO4, including exceptional speed of charging-discharging and excellent cycle stability. That is because the CA-graphene in the composite provides abundant porous channels for the diffusion of lithium ions. Moreover, it acts as a conducting network for easy charge transfer and as a divider, preventing the aggregation of LiFePO4 particles. Owing to these properties of CA-graphene, LiFePO4 could demonstrate enhanced and stably long-lasting electrochemical performance.

  7. Highly atom-economic synthesis of graphene/Mn3O4 hybrid composites for electrochemical supercapacitors

    Science.gov (United States)

    Jiangying, Qu; Feng, Gao; Quan, Zhou; Zhiyu, Wang; Han, Hu; Beibei, Li; Wubo, Wan; Xuzhen, Wang; Jieshan, Qiu

    2013-03-01

    A highly atom-economic procedure for the preparation of reduced graphene oxide/Mn3O4 (rGO/Mn3O4) composites is reported. Pristine graphene oxide/manganese sulfate (GO/MnSO4) suspension produced by modified Hummers method is utilized with high efficiency, which has been in situ converted into GO/Mn3O4 hybrid composite by air oxidation, then into rGO/Mn3O4 composite by means of dielectric barrier discharge (DBD) plasma-assisted deoxygenation. The Mn3O4 content of the rGO/Mn3O4 composites can be readily tailored. It is observed that Mn3O4 nanoparticles of 15-24 nm are well-dispersed on graphene sheets with Mn3O4 loading as high as 90%. The specific capacitance of the as-prepared rGO/Mn3O4 hybrids with 90% Mn3O4 reaches 193 F g-1 when employed as the electrode material in neutral Na2SO4 electrolyte solutions (76 F g-1 for pristine graphene and 95 F g-1 for pure Mn3O4), which indicates the positive synergetic effects from both graphene and attached Mn3O4. The method developed in this study should offer a new technique for the large scale and highly atom-economic production of graphene/MnOx composites for many applications.

  8. CMS Barrel Pixel Detector Overview

    CERN Document Server

    Kästli, H C; Erdmann, W; Gabathuler, K; Hörmann, C; Horisberger, Roland Paul; König, S; Kotlinski, D; Meier, B; Robmann, P; Rohe, T; Streuli, S

    2007-01-01

    The pixel detector is the innermost tracking device of the CMS experiment at the LHC. It is built from two independent sub devices, the pixel barrel and the end disks. The barrel consists of three concentric layers around the beam pipe with mean radii of 4.4, 7.3 and 10.2 cm. There are two end disks on each side of the interaction point at 34.5 cm and 46.5 cm. This article gives an overview of the pixel barrel detector, its mechanical support structure, electronics components, services and its expected performance.

  9. The water Cherenkov detector array for studies of cosmic rays at the University of Puebla

    International Nuclear Information System (INIS)

    Cotzomi, J.; Moreno, E.; Murrieta, T.; Palma, B.; Perez, E.; Salazar, H.; Villasenor, L.

    2005-01-01

    We describe the design and performance of a hybrid extensive air shower detector array built on the Campus of the University of Puebla (19 - bar N, 90 - bar W, 800g/cm 2 ) to measure the energy, arrival direction and composition of primary cosmic rays with energies around 1PeV, i.e., around the knee of the cosmic ray spectrum. The array consists of 3 water Cherenkov detectors of 1.86m 2 cross-section and 12 liquid scintillator detectors of 1m 2 distributed in a square grid with a detector spacing of 20m over an area of 4000m 2 . We discuss the calibration and stability of the array for both sets of detectors and report on preliminary measurements and reconstruction of the lateral distributions for the electromagnetic (EM) and muonic components of extensive air showers. We also discuss how the hybrid character of the array can be used to measure mass composition of the primary cosmic rays by estimating the relative contents of muons with respect to the EM component of extensive air showers. This facility is also used to train students interested in the field of cosmic rays

  10. Development of porous Ti6Al4V/chitosan sponge composite scaffold for orthopedic applications

    International Nuclear Information System (INIS)

    Guo, Miao; Li, Xiang

    2016-01-01

    A novel composite scaffold consisting of porous Ti6Al4V part filled with chitosan sponge was fabricated using a combination of electron beam melting and freeze-drying. The mechanical properties of porous Ti6Al4V part were examined via compressive test. The ultimate compressive strength was 85.35 ± 8.68 MPa and the compressive modulus was 2.26 ± 0.42 GPa. The microstructure of composite scaffold was characterized using scanning electron microscopy. The chitosan sponge filled in Ti6Al4V part exhibited highly porous and well-interconnected micro-pore architecture. The osteoblastic cells were seeded on scaffolds to test their seeding efficiency and biocompatibility. Significantly higher cell seeding efficiency was found on composite scaffold. The biological response of osteoblasts on composite scaffolds was superior in terms of improved cell attachment, higher proliferation, and well-spread morphology in relation to porous Ti6Al4V part. These results suggest that the Ti6Al4V/chitosan composite scaffold is potentially useful as a biomedical scaffold for orthopedic applications. - Highlights: • A novel composite scaffold with sufficient mechanical properties and favorable cell affinity environment was developed. • Significantly higher cell seeding efficiency was found on composite scaffold. • The osteoblasts on composite scaffolds showed well-spread morphology, improved cell attachment and higher proliferation.

  11. Detectors for the Atacama Cosmology Telescope

    Science.gov (United States)

    Marriage, Tobias Andrew

    The Atacama Cosmology Telescope (ACT) will make measurements of the brightness temperature anisotropy in the Cosmic Microwave Background (CMB) on degree to arcminute angular scales. The ACT observing site is located 5200 m near the top of Cerro Toco in the Atacama Desert of northern Chile. This thesis presents research on the detectors which capture the image of the CMB formed at ACT's focal plane. In the first chapter, the primary brightness temperature fluctuations in the Cosmic Microwave Background are reviewed. In Chapter 2, a calculation shows how the CMB brightness is translated by ACT to an input power to the detectors. Chapter 3 describes the ACT detectors in detail and presents the response and sensitivity of the detectors to the input power computed in Chapter 2. Chapter 4 describes the detector fabrication at NASA Goddard Space Flight Center. Chapter 5 summarizes experiments which characterize the ACT detector performance.

  12. Response of Moxon-Rae type gamma detectors for neutron capture cross section measurements

    International Nuclear Information System (INIS)

    Iyengar, K.V.K.; Lal, B.; Jhingan, M.L.

    1974-01-01

    A detector devised by Moxon and Rae for the absolute measurement of (n,γ) cross sections is briefly described. This detector is supposed to have an efficiency per MeV of γ-ray energy independent of the energy of the γ-rays. Such a detector consists of an electron converter placed before a thin plastic scintillator which detects the electron emitted by interaction of the γ-ray in the converter. The performance of this type of detector depends on the thickness and composition of the converter. Detailed Monte-Carlo calculations of the response for γ-ray energies from 0.2 to 12 MeV has been carried out for elements ranging from C to Bi and for a mixture of elements as well as for a mixture of an element plus compound, to find out the suitable material and thickness of the converter. Among the elements studied for the converter, Ni, Mo and Sn have a uniform response over the photon energy range 1-12 MeV. Out of these elements Mo has a low neutron capture cross section in the energy range 1-1000 keV and is thus to be preferred. A mixture of C + Bi 2 O 3 in the weight ratio 11.6 : 88.4 gives a uniform response over the photon energy range 1-12 MeV. (K.B.)

  13. Fabrication, structure, and properties of Fe{sub 3}O{sub 4}-C encapsulated with YVO{sub 4}:Eu{sup 3+} composites

    Energy Technology Data Exchange (ETDEWEB)

    Shi Jianhui; Tong Lizhu; Liu Deming; Yang Hua, E-mail: huayang86@sina.com [Jilin University, College of Chemistry (China)

    2012-03-15

    The use of carbon shells offers many advantages in surface coating or surface modification due to their surface with activated carboxyl and carbonyl groups. In this study, the Fe{sub 3}O{sub 4}-C-YVO{sub 4}:Eu{sup 3+} composites were prepared through a simple sol-gel process. Reactive carbon interlayer was introduced as a key component, which separates lanthanide-based luminescent component from the magnetite, more importantly, it effectively prevent oxidation of the Fe{sub 3}O{sub 4} core during the whole preparation process. The morphology, structure, magnetic, and luminescent properties of the composites were characterized by transmission electron microscopy (TEM), high-resolution TEM, X-ray diffraction, X-ray photoelectron spectra, VSM, and photoluminescent spectrophotometer. As a result, the Fe{sub 3}O{sub 4}-C/YVO{sub 4}:Eu{sup 3+} composites with well-crystallized and core-shell structure were prepared and the YVO{sub 4}:Eu{sup 3+} luminescent layer decorating the Fe{sub 3}O{sub 4}-C core-shell microspheres are about 10 nm. In addition, the Fe{sub 3}O{sub 4}-C-YVO{sub 4}:Eu{sup 3+} composites have the excellent magnetic and luminescent properties, which allow them great potential for bioapplications such as magnetic bioseparation, magnetic resonance imaging, and drug/gene delivery.

  14. Highly sensitive x-ray detectors in the low-energy range on n-type 4H-SiC epitaxial layers

    Energy Technology Data Exchange (ETDEWEB)

    Mandal, Krishna C.; Muzykov, Peter G. [Department of Electrical Engineering, University of South Carolina, Columbia, South Carolina 29208 (United States); Russell Terry, J. [Space Science and Applications Group (ISR-1), Intelligence and Space Research Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

    2012-07-30

    Schottky diodes on n-type 4H-SiC epitaxial layers have been fabricated for low-energy x-ray detection. The detectors were highly sensitive to soft x-rays and showed improved response compared to the commercial SiC UV photodiodes. Current-voltage characteristics at 475 K showed low leakage current revealing the possibility of high temperature operation. The high quality of the epi-layer was confirmed by x-ray diffraction and chemical etching. Thermally stimulated current measurements performed at 94-550 K revealed low density of deep levels which may cause charge trapping. No charge trapping on detectors' responsivity in the low x-ray energy was found.

  15. Detectors - Electronics; Detecteurs - Electronique

    Energy Technology Data Exchange (ETDEWEB)

    Bregeault, J.; Gabriel, J.L.; Hierle, G.; Lebotlan, P.; Leconte, A.; Lelandais, J.; Mosrin, P.; Munsch, P.; Saur, H.; Tillier, J. [Lab. de Physique Corpusculaire, Caen Univ., 14 (France)

    1998-04-01

    The reports presents the main results obtained in the fields of radiation detectors and associated electronics. In the domain of X-ray gas detectors for the keV range efforts were undertaken to rise the detector efficiency. Multiple gap parallel plate chambers of different types as well as different types of X {yields} e{sup -} converters were tested to improve the efficiency (values of 2.4% at 60 KeV were reached). In the field of scintillators a study of new crystals has been carried out (among which Lutetium orthosilicate). CdTe diode strips for obtaining X-ray imaging were studied. The complete study of a linear array of 8 CdTe pixels has been performed and certified. The results are encouraging and point to this method as a satisfying solution. Also, a large dimension programmable chamber was used to study the influence of temperature on the inorganic scintillators in an interval from -40 deg. C to +150 deg. C. Temperature effects on other detectors and electronic circuits were also investigated. In the report mentioned is also the work carried out for the realization of the DEMON neutron multidetector. For neutron halo experiments different large area Si detectors associated with solid and gas position detectors were realized. In the frame of a contract with COGEMA a systematic study of Li doped glasses was undertaken aiming at replacing with a neutron probe the {sup 3}He counters presently utilized in pollution monitoring. An industrial prototype has been realised. Other studies were related to integrated analog chains, materials for Cherenkov detectors, scintillation probes for experiments on fundamental processes, gas position sensitive detectors, etc. In the field of associated electronics there are mentioned the works related to the multidetector INDRA, data acquisition, software gamma spectrometry, automatic gas pressure regulation in detectors, etc

  16. Light Collection in the High Energy X-ray Detector with the Pixelated CdWO4 Scintillator using Monte Carlo Method

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Chang Hwy; Moon, Myung-Kook; Lee, Suhyun; Kim, Jongyul; Kim, Jeongho [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Park, Jong Won [Korea Research Institute of Ships and Ocean Engineering, Daejeon (Korea, Republic of)

    2015-05-15

    The performance of indirect detectors, which use the scintillator as CdWO{sub 4}, BGO, CsI, NaI, etc., are effected by optical properties of scintillator and geometrical condition of scintillator. Some of generated lights by interaction between x-ray photons and scintillator are collected at the photo-sensor and others are absorbed in scintillator or escape out of detector. In order to make the high performance image detector, detector should be able to gather the generated lights as much as possible. To minimize the loss of generated lights, thickness of scintillator is to be chosen appropriately. Therefore, the quality of the image detector using the pixelated scintillator is determined by scintillator size, reflectance of scintillator surface, electric noise, etc. In this study, we carried out a study the correlation between the number of collected light and the change of thickness of scintillator using Monte Carlo method. As shown in results, the optimal thickness of a scintillator should be properly selected depending on the incident x-ray energy. In case of without reflector, the scintillator thickness range for x-ray detection is thinner than other cases (with reflector). In the case of a scintillator with reflector, number of collected light and the optima thickness of a scintillator is higher and thicker than scintillator without reflector.

  17. SSC muon detector group report

    International Nuclear Information System (INIS)

    Carlsmith, D.; Groom, D.; Hedin, D.; Kirk, T.; Ohsugi, T.; Reeder, D.; Rosner, J.; Wojcicki, S.

    1986-01-01

    We report here on results from the Muon Detector Group which met to discuss aspects of muon detection for the reference 4π detector models put forward for evaluation at the Snowmass 1986 Summer Study. We report on: suitable overall detector geometry; muon energy loss mechanisms; muon orbit determination; muon momentum and angle measurement resolution; raw muon rates and trigger concepts; plus we identify SSC physics for which muon detection will play a significant role. We conclude that muon detection at SSC energies and luminosities is feasible and will play an important role in the evolution of physics at the SSC

  18. SSC muon detector group report

    Energy Technology Data Exchange (ETDEWEB)

    Carlsmith, D.; Groom, D.; Hedin, D.; Kirk, T.; Ohsugi, T.; Reeder, D.; Rosner, J.; Wojcicki, S.

    1986-01-01

    We report here on results from the Muon Detector Group which met to discuss aspects of muon detection for the reference 4..pi.. detector models put forward for evaluation at the Snowmass 1986 Summer Study. We report on: suitable overall detector geometry; muon energy loss mechanisms; muon orbit determination; muon momentum and angle measurement resolution; raw muon rates and trigger concepts; plus we identify SSC physics for which muon detection will play a significant role. We conclude that muon detection at SSC energies and luminosities is feasible and will play an important role in the evolution of physics at the SSC.

  19. Tribological characteristics of Si3N4-based composites in unlubricated sliding against steel ball

    International Nuclear Information System (INIS)

    Liu, C.-C.; Huang, J.-L.

    2004-01-01

    The dry-sliding wear mechanism of Si 3 N 4 -based composites against AISI-52100 steel ball was studied using a ball-on-disc mode in a reciprocation motion. The addition of TiN particles can increase the fracture toughness of Si 3 N 4 -based composites. The fracture toughness of Si 3 N 4 -based composites played an important role for wear behavior. The Si 3 N 4 -based composites exhibits a small friction and wear coefficient compared to monolithic Si 3 N 4 . Atomic force microscopy (AFM) studies displayed fine wear grooves along the sliding traces. The subsurface deformation shows that the microcrack propagation extends along the TiN/Si 3 N 4 grain interface. The wear mechanisms were determined with scanning electron microscopy, transmission electron microscopy, X-ray diffraction and atomic force microscopy

  20. Solid-state cadmium telluride radiation detector

    Energy Technology Data Exchange (ETDEWEB)

    Takeuchi, Yoji; Kitamoto, Hisashi; Hosomatsu, Haruo

    1984-09-01

    The growth of CdTe single crystal and its application to CdTe detector array was studied for X-ray computed tomography (XCT) equipment. A p-type CdTe single crystal with 10/sup 4/ ohm.cm specific resistivity was grown in a quartz ampoule under vapor pressure control of Cd in a vertical Bridgman furnace. An 18-element detector array was fabricated with this single crystal. The detector was operated with no bias and the sensitivity was confirmed to be between 2.8 x 10/sup -12/ and 14 x 10/sup -12/ A.h/(R.mm/sup 2/). Commercial CdTe single crystal was used to manufacture as 560-element detector array for XCT. Results show that CdTe detector is sensitive, linear and has high resolution.

  1. Magnesium borate radiothermoluminescent detectors

    International Nuclear Information System (INIS)

    Kazanskaya, V.A.; Kuzmin, V.V.; Minaeva, E.E.; Sokolov, A.D.

    1974-01-01

    In the report the technology of obtaining polycrystalline magnesium borate activated by dysprosium is described briefly and the method of preparing the tabletted detectors from it is presented. The dependence of the light sum of the samples on the proportion of the components and on the sintering regime has shown that the most sensitive material is obtained at the proportion of boric anhydride and magnesium oxide 2.2-2.4 and at the dysprosium concentration about 1 milligram-atom per gram molecule of the base. The glow curve of such a material has a simple form with one peak the maximum of which is located at 190-200 0 C. The measurement of the main dosimetric characteristics of the magnesium borate tabletted detectors and the comparison with similar parmaeters of the lithium fluoride tabletted detectors have shown that at practically identical effective number the former detectors have the following substantial advantages: the sensitivity is ten-twenty times as large, they are substantially more technological on synthesis of the radiothermoluminophor and during the production of the tabletted detectors, they have a simple glow curve, they do not require the utilization of the thermocycling during the use. (author)

  2. A novel detector assembly for detecting thermal neutrons, fast neutrons and gamma rays

    Energy Technology Data Exchange (ETDEWEB)

    Cester, D., E-mail: davide.cester@gmail.com [Dipartimento di Fisica ed Astronomia dell' Università di Padova, Via Marzolo 8, I-35131 Padova (Italy); Lunardon, M.; Moretto, S. [Dipartimento di Fisica ed Astronomia dell' Università di Padova, Via Marzolo 8, I-35131 Padova (Italy); INFN Sezione di Padova, Via Marzolo 8, I-35131 Padova (Italy); Nebbia, G. [INFN Sezione di Padova, Via Marzolo 8, I-35131 Padova (Italy); Pino, F. [Dipartimento di Fisica ed Astronomia dell' Università di Padova, Via Marzolo 8, I-35131 Padova (Italy); Sajo-Bohus, L. [Dipartimento di Fisica ed Astronomia dell' Università di Padova, Via Marzolo 8, I-35131 Padova (Italy); Laboratorio de Fisica Nuclear, Universidad Simon Bolivar, Apartado 89000, 1080 A Caracas (Venezuela, Bolivarian Republic of); Stevanato, L.; Bonesso, I.; Turato, F. [Dipartimento di Fisica ed Astronomia dell' Università di Padova, Via Marzolo 8, I-35131 Padova (Italy)

    2016-09-11

    A new composite detector has been developed by combining two different commercial scintillators. The device has the capability to detect gamma rays as well as thermal and fast neutrons; the signal discrimination between the three types is performed on-line by means of waveform digitizers and PSD algorithms. This work describes the assembled detector and its discrimination performance to be employed in the applied field.

  3. A novel detector assembly for detecting thermal neutrons, fast neutrons and gamma rays

    International Nuclear Information System (INIS)

    Cester, D.; Lunardon, M.; Moretto, S.; Nebbia, G.; Pino, F.; Sajo-Bohus, L.; Stevanato, L.; Bonesso, I.; Turato, F.

    2016-01-01

    A new composite detector has been developed by combining two different commercial scintillators. The device has the capability to detect gamma rays as well as thermal and fast neutrons; the signal discrimination between the three types is performed on-line by means of waveform digitizers and PSD algorithms. This work describes the assembled detector and its discrimination performance to be employed in the applied field.

  4. Activation neutron detector

    International Nuclear Information System (INIS)

    Ambardanishvili, T.S.; Kolomiitsev, M.A.; Zakharina, T.Y.; Dundua, V.J.; Chikhladze, N.V.

    1976-01-01

    An activation neutron detector made as a moulded and cured composition of a material capable of being neutron-activated is described. The material is selected from a group consisting of at least two chemical elements, a compound of at least two chemical elements and their mixture, each of the chemical elements and their mixture, each of the chemical elements being capable of interacting with neutrons to form radioactive isotopes having different radiation energies when disintegrating. The material capable of being neutron-activated is distributed throughout the volume of a polycondensation resin inert with respect to neutrons and capable of curing. 17 Claims, No Drawings

  5. Advantages and Limits of 4H-SIC Detectors for High- and Low-Flux Radiations

    Science.gov (United States)

    Sciuto, A.; Torrisi, L.; Cannavò, A.; Mazzillo, M.; Calcagno, L.

    2017-11-01

    Silicon carbide (SiC) detectors based on Schottky diodes were used to monitor low and high fluxes of photons and ions. An appropriate choice of the epilayer thickness and geometry of the surface Schottky contact allows the tailoring and optimizing the detector efficiency. SiC detectors with a continuous front electrode were employed to monitor alpha particles in a low-flux regime emitted by a radioactive source with high energy (>5.0 MeV) or generated in an ion implanter with sub-MeV energy. An energy resolution value of 0.5% was measured in the high energy range, while, at energy below 1.0 MeV, the resolution becomes 10%; these values are close to those measured with a traditional silicon detector. The same SiC devices were used in a high-flux regime to monitor high-energy ions, x-rays and electrons of the plasma generated by a high-intensity (1016 W/cm2) pulsed laser. Furthermore, SiC devices with an interdigit Schottky front electrode were proposed and studied to overcome the limits of the such SiC detectors in the detection of low-energy (˜1.0 keV) ions and photons of the plasmas generated by a low-intensity (1010 W/cm2) pulsed laser. SiC detectors are expected to be a powerful tool for the monitoring of radioactive sources and ion beams produced by accelerators, for a complete characterization of radiations emitted from laser-generated plasmas at high and low temperatures, and for dosimetry in a radioprotection field.

  6. Studies of Cosmic Ray Composition and Air Shower Structure with the Pierre Auger Observatory

    Energy Technology Data Exchange (ETDEWEB)

    Abraham, : J.; Abreu, P.; Aglietta, M.; Aguirre, C.; Ahn, E.J.; Allard, D.; Allekotte, I.; Allen, J.; Alvarez-Muniz, J.; Ambrosio, M.; Anchordoqui, L.

    2009-06-01

    These are presentations to be presented at the 31st International Cosmic Ray Conference, in Lodz, Poland during July 2009. It consists of the following presentations: (1) Measurement of the average depth of shower maximum and its fluctuations with the Pierre Auger Observatory; (2) Study of the nuclear mass composition of UHECR with the surface detectors of the Pierre Auger Observatory; (3) Comparison of data from the Pierre Auger Observatory with predictions from air shower simulations: testing models of hadronic interactions; (4) A Monte Carlo exploration of methods to determine the UHECR composition with the Pierre Auger Observatory; (5) The delay of the start-time measured with the Pierre Auger Observatory for inclined showers and a comparison of its variance with models; (6) UHE neutrino signatures in the surface detector of the Pierre Auger Observatory; and (7) The electromagnetic component of inclined air showers at the Pierre Auger Observatory.

  7. Porous quasi three-dimensional nano-Mn3O4 + PbO2 composite as supercapacitor electrode material

    International Nuclear Information System (INIS)

    Dan Yuanyuan; Lin Haibo; Liu Xiaolei; Lu Haiyan; Zhao Jingzhe; Shi Zhan; Guo Yupeng

    2012-01-01

    Highlights: ► We prepare nano-PbO 2 + Mn 3 O 4 composite material by composite deposition method. ► The nano-PbO 2 + Mn 3 O 4 composite has porous quasi three-dimensional structure. ► Maximum electrochemically effective area (R F ) of the composite is 72. ► The composite shows high specific capacitance up to ∼340 F g −1 . ► A general knowledge of the pesudocapacitance behavior of the composite is acquired. - Abstract: Nano-Mn 3 O 4 + PbO 2 composite electrode materials with different compositions are prepared by anodic composite electrodeposition in Pb 2+ plating solution containing suspended nano-Mn 3 O 4 particles (40–60 nm). The particles are synthesized via one-step homogeneous precipitation at low temperature. The composite materials are characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM) analyses. The results indicate that the composite composed of γ-Mn 3 O 4 and β-PbO 2 is porous and quasi three-dimensional (3D), and its maximum electrochemically effective area ratio (R F ) is 72. The capacitance performance of the composite is determined by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and charge–discharge test. The composite shows a high specific capacitance up to 338 F g −1 .

  8. Time differential {sup 57}Fe Mössbauer spectrometer with unique 4π YAP:Ce 122.06 keV gamma-photon detector

    Energy Technology Data Exchange (ETDEWEB)

    Novak, Petr [Department of Experimental Physics, Faculty of Science, Palacky University, 17. listopadu 1192/12, 77 146 Olomouc (Czech Republic); Pechousek, Jiri, E-mail: jiri.pechousek@upol.cz [Department of Experimental Physics, Faculty of Science, Palacky University, 17. listopadu 1192/12, 77 146 Olomouc (Czech Republic); Prochazka, Vit [Department of Experimental Physics, Faculty of Science, Palacky University, 17. listopadu 1192/12, 77 146 Olomouc (Czech Republic); Navarik, Jakub [Regional Centre of Advanced Technologies and Materials, Department of Experimental Physics, Faculty of Science, Palacky University, 17. listopadu 12, 77 146 Olomouc (Czech Republic); Kouril, Lukas; Kohout, Pavel; Vrba, Vlastimil [Department of Experimental Physics, Faculty of Science, Palacky University, 17. listopadu 1192/12, 77 146 Olomouc (Czech Republic); Machala, Libor [Regional Centre of Advanced Technologies and Materials, Department of Experimental Physics, Faculty of Science, Palacky University, 17. listopadu 12, 77 146 Olomouc (Czech Republic)

    2016-10-01

    This paper presents a conceptually new design of the {sup 57}Fe Time Differential Mössbauer Spectrometer (TDMS) with the gamma-photon detector optimized for registration of a radiation emitted in a maximum solid angle. A high detection efficiency of 80% in 4π region was achieved for 122.06 keV photons emitted from {sup 57}Co source. Detector parameters have been optimized for the use in the Time Differential Mössbauer Spectroscopy where the high time resolution in range of 176–200 ns is highly required. Technical concept of the TDMS is based on the virtual instrumentation technique and uses fast digital oscilloscope. Performance and detector utilization have been clarified by decreasing the Mössbauer spectral line-width of K{sub 2}MgFe(CN){sub 6} reference sample from 0.33 mm/s (integral mode) to 0.23 mm/s (time differential mode). This report also describes characterization and utilization of the detector together with additional electronic blocks and two-channel fast data-acquisition system construction.

  9. Detector calibration measurements in CRESST

    Energy Technology Data Exchange (ETDEWEB)

    Westphal, W. [Technische Universitaet Muenchen, Physik Department E15, James-Franck-Strasse, D-85748 Garching (Germany)]. E-mail: westphal@ph.tum.de; Coppi, C. [Technische Universitaet Muenchen, Physik Department E15, James-Franck-Strasse, D-85748 Garching (Germany); Feilitzsch, F. von [Technische Universitaet Muenchen, Physik Department E15, James-Franck-Strasse, D-85748 Garching (Germany); Isaila, C. [Technische Universitaet Muenchen, Physik Department E15, James-Franck-Strasse, D-85748 Garching (Germany); Jagemann, T. [Eberhard Karls Universitaet Tuebingen, Physikalisches Institut I, Auf der Morgenstelle 14, D-72076 Tuebingen (Germany); Jochum, J. [Eberhard Karls Universitaet Tuebingen, Physikalisches Institut I, Auf der Morgenstelle 14, D-72076 Tuebingen (Germany); Koenig, J. [Technische Universitaet Muenchen, Physik Department E15, James-Franck-Strasse, D-85748 Garching (Germany); Lachenmaier, T. [Technische Universitaet Muenchen, Physik Department E15, James-Franck-Strasse, D-85748 Garching (Germany); Lanfranchi, J.-C. [Technische Universitaet Muenchen, Physik Department E15, James-Franck-Strasse, D-85748 Garching (Germany); Potzel, W. [Technische Universitaet Muenchen, Physik Department E15, James-Franck-Strasse, D-85748 Garching (Germany); Rau, W. [Technische Universitaet Muenchen, Physik Department E15, James-Franck-Strasse, D-85748 Garching (Germany); Stark, M. [Technische Universitaet Muenchen, Physik Department E15, James-Franck-Strasse, D-85748 Garching (Germany); Wernicke, D. [Technische Universitaet Muenchen, Physik Department E15, James-Franck-Strasse, D-85748 Garching (Germany); VeriCold Technologies GmbH, Bahnhofstrasse 21, D-85737 Ismaning (Germany)

    2006-04-15

    The CRESST dark matter experiment uses the simultaneous measurement of the scintillation light and the heat signal of a CaWO{sub 4} crystal to discriminate between background electron recoil and nuclear recoil events. At the Technical University of Munich calibration measurements have been performed to characterize the detectors. These measurements include the determination of the light output and scintillation time constants of CaWO{sub 4} at temperatures below 50 mK. The setup used in these measurements consist of a CaWO{sub 4} crystal, which is mounted in a reflective housing together with a silicon light detector carrying an Ir/Au transition edge sensor (TES) evaporated directly onto it.

  10. Radiation detectors for reactors

    International Nuclear Information System (INIS)

    Balagi, V.

    2005-01-01

    Detection and measurement of radiation plays a vital role in nuclear reactors from the point of view of control and safety, personnel protection and process control applications. Various types of radiation are measured over a wide range of intensity. Consequently a variety of detectors find use in nuclear reactors. Some of these devices have been developed in Electronics Division. They include gas-filled detectors such as 10 B-lined proportional counters and chambers, fission detectors and BF 3 counters are used for the measurement of neutron flux both for reactor control and safety, process control as well as health physics instrumentation. In-core neutron flux instrumentation employs the use detectors such as miniature fission detectors and self-powered detectors. In this development effort, several indigenous materials, technologies and innovations have been employed to suit the specific requirement of nuclear reactor applications. This has particular significance in view of the fact that several new types of reactors such as P-4, PWR and AHWR critical facilities, FBTR, PFBR as well as the refurbishment of old units like CIRUS are being developed. The development work has sought to overcome some difficulties associated with the non-availability of isotopically enriched neutron-sensing materials, achieving all-welded construction etc. The present paper describes some of these innovations and performance results. (author)

  11. The LHCb RICH system; detector description and operation

    Energy Technology Data Exchange (ETDEWEB)

    Papanestis, A., E-mail: antonis.papanestis@stfc.ac.uk

    2014-12-01

    Two RICH detectors provide positive charged hadron identification in the LHCb experiment at the Large Hadron Collider at CERN. RICH 1 covers the full acceptance of the spectrometer and contains two radiators: aerogel and C{sub 4}F{sub 10}. RICH 2 covers half the acceptance and uses CF{sub 4} as a Cherenkov radiator. Photon detection is performed by the Hybrid Photon Detectors (HPDs), with silicon pixel sensors and bump-bonded readout encapsulated in a vacuum tube for efficient, low-noise single photon detection. The LHCb RICH detectors form a complex system of three radiators, 120 mirrors and 484 photon detectors operating in the very challenging environment of the LHC. The high performance of the system in pion and kaon identification in the momentum range of 2–100 GeV/c is reached only after careful calibration of many parameters. Operational efficiency above 99% was achieved by a high level of automatization in the operation of the detectors, from switching-on to error recovery. The challenges of calibrating and operating such a system will be presented. - Highlights: • This paper describes the operation and calibration of the LHCb RICH detectors. • The scintillation of CF{sub 4} was successfully suppressed with CO{sub 2}. • The refractive index of the gas radiators was calibrated with data to an accuracy better than 0.1%. • The Hybrid Photons Detectors were calibrated for operation in a magnetic field without loss of resolution.

  12. Operational Experience with the ATLAS Pixel Detector

    CERN Document Server

    Lantzsch, Kerstin; The ATLAS collaboration

    2016-01-01

    Run 2 of the LHC is providing new challenges to track and vertex reconstruction with higher energies, denser jets and higher rates. Therefore the ATLAS experiment has constructed the first 4-layer Pixel detector in HEP, installing a new Pixel layer, also called Insertable B-Layer (IBL). In addition the Pixel detector was refurbished with new service quarter panels to recover about 3% of defective modules lost during run 1 and a new optical readout system to readout the data at higher speed while reducing the occupancy when running with increased luminosity. The commissioning, operation and performance of the 4-layer Pixel Detector will be presented.

  13. Department of Radiation Detectors: Overview

    International Nuclear Information System (INIS)

    Piekoszewski, J.

    1998-01-01

    (full text) Work carried out in 1997 in the Department of Radiation Detectors concentrated on three subjects: (i) Semiconductor Detectors (ii) X-ray Tube Generators (iii) Material Modification using Ion and Plasma Beams. Semiconductor detectors: Semiconductor detectors of ionizing radiation are among the basic tools utilized in such fields of research and industry as nuclear physics, high energy physics, medical (oncology) radiotherapy, radiological protection, environmental monitoring, energy dispersive X-ray fluorescence non-destructive analysis of chemical composition, nuclear power industry. The Department all objectives are: - search for new types of detectors, - adapting modern technologies (especially of industrial microelectronics) to detector manufacturing, - producing unique detectors tailored for physics experiments, - manufacturing standard detectors for radiation measuring instruments, - scientific development of the staff. These 1997 objectives were accomplished particularly by: - research on unique detectors for nuclear physics (e.g. transmission type Si(Li) detectors with extremely thin entrance and exit window), - development of technology of high-resistivity (HRSi) silicon detectors and thermoelectric cooling systems (KBN grant), - study of the applicability of industrial planar technology in producing detectors, - manufacturing detectors developed in previous years, re-generating and servicing customer detectors of various origin. In accomplishing of the above, the Department cooperated with interested groups of physicists from our Institute (P-I and P-II Departments), Warsaw University, Warsaw Heavy Ion Laboratory and with some technology Institutes based in Warsaw (ITME, ITE). Some detectors and services have been delivered to customers on a commercial basis. X-Rat tube generators: The Department conducts research on design and technology of producing X-ray generators based on X-ray tubes of special construction. In 1997, work on a special

  14. Detectors for proton counting. Si-APD and scintillation detectors

    International Nuclear Information System (INIS)

    Kishimoto, Shunji

    2008-01-01

    Increased intensity of synchrotron radiation requests users to prepare photon pulse detectors having higher counting rates. As detectors for photon counting, silicon-avalanche photodiode (Si-APD) and scintillation detectors were chosen for the fifth series of detectors. Principle of photon detection by pulse and need of amplification function of the detector were described. Structure and working principle, high counting rate measurement system, bunch of electrons vs. counting rate, application example of NMR time spectroscopy measurement and comments for users were described for the Si-APD detector. Structure of scintillator and photomultiplier tube, characteristics of scintillator and performance of detector were shown for the NaI detector. Future development of photon pulse detectors was discussed. (T. Tanaka)

  15. A recoil detector of Koala experiment at HESR

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Huagen [Forschungszentrum Juelich (Germany)

    2015-07-01

    The concept of the luminosity detector for the PANDA experiment is based on measuring antiproton-proton elastic scattering in the Coulomb-nuclear interference region by 4 planes of HV-MAPS tracking detectors. The absolute precision is limited by the lack of existing data of the physics quantities σ{sub tot}, ρ and b describing the differential cross section as a function of squared 4-momentum transfer t in the relevant beam momentum region. Therefore, the so-called Koala experiment has been proposed to measure antiproton-proton elastic scattering. The goal of Koala experiment is to measure a wide range of t-distribution to determine the parameters σ{sub tot}, ρ and b. The idea is to measure the scattered beam antiprotons at forward angles by tracking detectors and the recoil target protons near 90 {sup circle} by energy detectors. In order to validate this method a recoil detector has been designed and built. Commissioning of the recoil detector by measuring proton-proton elastic scattering has been performed at COSY. Preliminary results of the commissioning are presented.

  16. A low mass pixel detector upgrade for CMS

    CERN Document Server

    Kästli, H C

    2010-01-01

    The CMS pixel detector has been designed for a peak luminosity of 10^34cm-2s-1 and a total dose corresponding to 2 years of LHC operation at a radius of 4 cm from the interaction region. Parts of the pixel detector will have to be replaced until 2015. The detector performance will be degraded for two reasons: radiation damage of the innermost layers and the planned increase of the LHC peak luminosity by a factor of 2-3. Based on the experience in planning, constructing and commissioning of the present pixel detector, we intend to upgrade the whole pixel detector in 2015. The main focus is on lowering the material budget and adding more tracking points. We will present the design of a new low mass pixel system consisting of 4 barrel layers and 3 end cap disks on each side. The design comprises of thin detector modules and a lightweight mechanical support structure using CO2 cooling. In addition, large efforts have been made to move material from the services out of the tracking region.

  17. The 4D Composite Higgs

    CERN Document Server

    De Curtis, Stefania; Tesi, Andrea

    2012-01-01

    We propose a four dimensional description of Composite Higgs Models which represents a complete framework for the physics of the Higgs as a pseudo-Nambu-Goldstone boson. Our setup captures all the relevant features of 5D models and more in general of composite Higgs models with partial compositeness. We focus on the minimal scenario where we include a single multiplet of resonances of the composite sector, as these will be the only degrees of freedom which might be accessible at the LHC. This turns out to be sufficient to compute the effective potential and derive phenomenological consequences of the theory. Moreover our simplified approach is well adapted to simulate these models at the LHC. We also consider the impact of non-minimal terms in the effective lagrangian which do not descend from a 5D theory and could be of phenomenological relevance, for example contributing to the S-parameter.

  18. Benchmarking the Geant4 full system simulation of an associated alpha-particle detector for use in a D-T neutron generator.

    Science.gov (United States)

    Zhang, Xiaodong; Hayward, Jason P; Cates, Joshua W; Hausladen, Paul A; Laubach, Mitchell A; Sparger, Johnathan E; Donnald, Samuel B

    2012-08-01

    The position-sensitive alpha-particle detector used to provide the starting time and initial direction of D-T neutrons in a fast-neutron imaging system was simulated with a Geant4-based Monte Carlo program. The whole detector system, which consists of a YAP:Ce scintillator, a fiber-optic faceplate, a light guide, and a position-sensitive photo-multiplier tube (PSPMT), was modeled, starting with incident D-T alphas. The scintillation photons, whose starting time follows the distribution of a scintillation decay curve, were produced and emitted uniformly into a solid angle of 4π along the track segments of the alpha and its secondaries. Through tracking all photons and taking into account the quantum efficiency of the photocathode, the number of photoelectrons and their time and position distributions were obtained. Using a four-corner data reconstruction formula, the flood images of the alpha detector with and without optical grease between the YAP scintillator and the fiber-optic faceplate were obtained, which show agreement with the experimental results. The reconstructed position uncertainties of incident alpha particles for both cases are 1.198 mm and 0.998 mm respectively across the sensitive area of the detector. Simulation results also show that comparing with other faceplates composed of 500 μm, 300 μm, and 100 μm fibers, the 10-μm-fiber faceplate is the best choice to build the detector for better position performance. In addition, the study of the background originating inside the D-T generator suggests that for 500-μm-thick YAP:Ce coated with 1-μm-thick aluminum, and very good signal-to-noise ratio can be expected through application of a simple threshold. Copyright © 2012 Elsevier Ltd. All rights reserved.

  19. Development of a Geant4 application to characterise a prototype neutron detector based on three orthogonal 3He tubes inside an HDPE sphere.

    Science.gov (United States)

    Gracanin, V; Guatelli, S; Prokopovich, D; Rosenfeld, A B; Berry, A

    2017-01-01

    The Bonner Sphere Spectrometer (BSS) system is a well-established technique for neutron dosimetry that involves detection of thermal neutrons within a range of hydrogenous moderators. BSS detectors are often used to perform neutron field surveys in order to determine the ambient dose equivalent H*(10) and estimate health risk to personnel. There is a potential limitation of existing neutron survey techniques, since some detectors do not consider the direction of the neutron field, which can result in overly conservative estimates of dose in neutron fields. This paper shows the development of a Geant4 simulation application to characterise a prototype neutron detector based on three orthogonal 3 He tubes inside a single HDPE sphere built at the Australian Nuclear Science and Technology Organisation (ANSTO). The Geant4 simulation has been validated with respect to experimental measurements performed with an Am-Be source. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

  20. Workshop on detectors for third-generation synchrotron sources: Proceedings

    International Nuclear Information System (INIS)

    1994-12-01

    The aims of the workshop were (1) to acquaint APS users with current R and D being carried out on detectors, (2) to identify new detector systems possible during the next five years, (3) to identify new detectors theoretically possible in the future, (4) to stimulate interactions between user groups and detector developers, and (5) to obtain recommendations from expert panels on technical issues needing resolution. Development of detectors at ESRF, Spring-8, BNL, CERN and LBL are included

  1. Workshop on detectors for third-generation synchrotron sources: Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-12-01

    The aims of the workshop were (1) to acquaint APS users with current R and D being carried out on detectors, (2) to identify new detector systems possible during the next five years, (3) to identify new detectors theoretically possible in the future, (4) to stimulate interactions between user groups and detector developers, and (5) to obtain recommendations from expert panels on technical issues needing resolution. Development of detectors at ESRF, Spring-8, BNL, CERN and LBL are included.

  2. Vapor diffusion synthesis of rugby-shaped CoFe2O4/graphene composites as absorbing materials

    International Nuclear Information System (INIS)

    Zhang, Shenli; Jiao, Qingze; Hu, Ju; Li, Jingjing; Zhao, Yun; Li, Hansheng; Wu, Qin

    2015-01-01

    Graphical abstract: CoFe 2 O 4 rugbies/graphene composites were prepared using a vapor diffusion method followed by calcination. As-synthesized rugby-like CoFe 2 O 4 particles were distributed on the graphene sheet. PVP played a key role for the formation of rugby-shaped morphology of CoFe 2 O 4 particles. A minimum reflection loss of −39.0 dB was observed at 10.9 GHz for the CoFe 2 O 4 rugbies/graphene composites with a thickness of 2 mm, and the effective absorption bandwidth was 4.7 GHz. The CoFe 2 O 4 rugbies/graphene composites exhibited better microwave absorbing performance than that of the CoFe 2 O 4 nanoparticles/graphene composites prepared without PVP. - Highlights: • CoFe 2 O 4 rugbies/graphene hybrids were synthesized using a vapor diffusion method. • PVP played a key role for the formation of CoFe 2 O 4 rugbies. • CoFe 2 O 4 rugbies/graphene composites showed excellent microwave absorbing property. - Abstract: Rugby-shaped CoFe 2 O 4 /graphene composites were synthesized using a vapor diffusion method in combination with calcination. The morphologies and structures of the products were characterized by field emission scanning electron microscopy, X-ray diffractometer, Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. The magnetic and electromagnetic parameters were measured using a vibrating sample magnetometer and a vector network analyzer, respectively. Results show that rugby-shaped CoFe 2 O 4 particles are distributed on graphene sheets. A minimum reflection loss (RL) of −39.0 dB is observed at 10.9 GHz for the sample with a thickness of 2.0 mm, and the effective absorption frequency (RL < −10 dB) ranges from 9.6 to 14.3 GHz, indicating the excellent microwave absorption performance of the products. The absorbing performance of the CoFe 2 O 4 rugbies/graphene composites is better than that of the CoFe 2 O 4 nanoparticles/graphene composites

  3. A portable gas recirculation unit for gaseous detectors

    Science.gov (United States)

    Guida, R.; Mandelli, B.

    2017-10-01

    The use of greenhouse gases (usually C2H2F4, CF4 and SF6) is sometimes necessary to achieve the required performance for some gaseous detectors. The consumption of these gases in the LHC systems is reduced by recycling the gas mixture thanks to a complex gas recirculation system. Beyond greenhouse gas consumption due to LHC systems, a considerable contribution is generated by setups used for LHC detector upgrade projects, R&D activities, detector quality assurance or longevity tests. In order to minimise this emission, a new flexible and portable gas recirculation unit has been developed. Thanks to its low price, flexibility and user-friendly operation it can be easily adapted for the different types of detector systems and set-ups.

  4. A New Virtual Point Detector Concept for a HPGe detector

    International Nuclear Information System (INIS)

    Byun, Jong In; Yun, Ju Yong

    2009-01-01

    For last several decades, the radiation measurement and radioactivity analysis techniques using gamma detectors have been well established. Especially , the study about the detection efficiency has been done as an important part of gamma spectrometry. The detection efficiency depends strongly on source-to-detector distance. The detection efficiency with source-to-detector distance can be expressed by a complex function of geometry and physical characteristics of gamma detectors. In order to simplify the relation, a virtual point detector concept was introduced by Notea. Recently, further studies concerning the virtual point detector have been performed. In previous other works the virtual point detector has been considered as a fictitious point existing behind the detector end cap. However the virtual point detector position for the front and side of voluminous detectors might be different due to different effective central axis of them. In order to more accurately define the relation, therefore, we should consider the virtual point detector for the front as well as side and off-center of the detector. The aim of this study is to accurately define the relation between the detection efficiency and source-to-detector distance with the virtual point detector. This paper demonstrates the method to situate the virtual point detectors for a HPGe detector. The new virtual point detector concept was introduced for three area of the detector and its characteristics also were demonstrated by using Monte Carlo Simulation method. We found that the detector has three virtual point detectors except for its rear area. This shows that we should consider the virtual point detectors for each area when applying the concept to radiation measurement. This concept can be applied to the accurate geometric simplification for the detector and radioactive sources.

  5. Development of a custom on-line ultrasonic vapour analyzer/flowmeter for the ATLAS inner detector, with application to gaseous tracking and Cherenkov detectors

    CERN Document Server

    Bates, R.; Berry, S.; Berthoud, J.; Bitadze, A.; Bonneau, P.; Botelho-Direito, J.; Bousson, N.; Boyd, G.; Bozza, G.; Da Riva, E.; Degeorge, C.; DiGirolamo, B.; Doubek, M.; Godlewski, J.; Hallewell, G.; Katunin, S.; Lombard, D.; Mathieu, M.; McMahon, S.; Nagai, K.; Perez-Rodriguez, E.; Rossi, C.; Rozanov, A.; Vacek, V.; Vitek, M.; Zwalinski, L.

    2013-01-01

    Precision sound velocity measurements can simultaneously determine binary gas composition and flow. We have developed an analyzer with custom electronics, currently in use in the ATLAS inner detector, with numerous potential applications. The instrument has demonstrated ~0.3% mixture precision for C3F8/C2F6 mixtures and < 10-4 resolution for N2/C3F8 mixtures. Moderate and high flow versions of the instrument have demonstrated flow resolutions of +/- 2% F.S. for flows up to 250 l.min-1, and +/- 1.9% F.S. for linear flow velocities up to 15 ms-1; the latter flow approaching that expected in the vapour return of the thermosiphon fluorocarbon coolant recirculator being built for the ATLAS silicon tracker.

  6. Facile synthesis of hybrid CNTs/NiCo2S4 composite for high performance supercapacitors

    Science.gov (United States)

    Li, Delong; Gong, Youning; Pan, Chunxu

    2016-07-01

    In this work, a novel carbon nanotubes (CNTs)/NiCo2S4 composite for high performance supercapacitors was prepared via a simple chemical bath deposition combined with a post-anion exchange reaction. The morphologies and phase structures of the composites were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), Raman spectroscopy (Raman), X-ray photoelectron spectroscopy (XPS) and low-temperature sorption of nitrogen (BET). The electro-chemical tests revealed that the CNT/NiCo2S4 composite exhibited high electrochemical performance, because the CNTs were used as a conductive network for the NiCo2S4 hexagonal nanoplates. Compared with pure NiCo2S4 and the mechanically mixed CNTs/NiCo2S4 composite, the CNTs/NiCo2S4 composite electrode material exhibited excellent supercapacitive performance, such as a high specific capacitance up to 1537 F/g (discharge current density of 1 A/g) and an outstanding rate capability of 78.1% retention as the discharge current density increased to 100 A/g. It is therefore expected to be a promising alternative material in the area of energy storage.

  7. Facile synthesis of hybrid CNTs/NiCo2S4 composite for high performance supercapacitors.

    Science.gov (United States)

    Li, Delong; Gong, Youning; Pan, Chunxu

    2016-07-11

    In this work, a novel carbon nanotubes (CNTs)/NiCo2S4 composite for high performance supercapacitors was prepared via a simple chemical bath deposition combined with a post-anion exchange reaction. The morphologies and phase structures of the composites were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), Raman spectroscopy (Raman), X-ray photoelectron spectroscopy (XPS) and low-temperature sorption of nitrogen (BET). The electro-chemical tests revealed that the CNT/NiCo2S4 composite exhibited high electrochemical performance, because the CNTs were used as a conductive network for the NiCo2S4 hexagonal nanoplates. Compared with pure NiCo2S4 and the mechanically mixed CNTs/NiCo2S4 composite, the CNTs/NiCo2S4 composite electrode material exhibited excellent supercapacitive performance, such as a high specific capacitance up to 1537 F/g (discharge current density of 1 A/g) and an outstanding rate capability of 78.1% retention as the discharge current density increased to 100 A/g. It is therefore expected to be a promising alternative material in the area of energy storage.

  8. Transmutation detectors

    Energy Technology Data Exchange (ETDEWEB)

    Viererbl, L., E-mail: vie@ujv.c [Research Centre Rez Ltd. (Czech Republic); Nuclear Research Institute Rez plc (Czech Republic); Lahodova, Z. [Research Centre Rez Ltd. (Czech Republic); Nuclear Research Institute Rez plc (Czech Republic); Klupak, V. [Nuclear Research Institute Rez plc (Czech Republic); Sus, F. [Research Centre Rez Ltd. (Czech Republic); Nuclear Research Institute Rez plc (Czech Republic); Kucera, J. [Research Centre Rez Ltd. (Czech Republic); Nuclear Physics Institute, Academy of Sciences of the Czech Republic (Czech Republic); Kus, P.; Marek, M. [Research Centre Rez Ltd. (Czech Republic); Nuclear Research Institute Rez plc (Czech Republic)

    2011-03-11

    We have designed a new type of detectors, called transmutation detectors, which can be used primarily for neutron fluence measurement. The transmutation detector method differs from the commonly used activation detector method in evaluation of detector response after irradiation. Instead of radionuclide activity measurement using radiometric methods, the concentration of stable non-gaseous nuclides generated by transmutation in the detector is measured using analytical methods like mass spectrometry. Prospective elements and nuclear reactions for transmutation detectors are listed and initial experimental results are given. The transmutation detector method could be used primarily for long-term measurement of neutron fluence in fission nuclear reactors, but in principle it could be used for any type of radiation that can cause transmutation of nuclides in detectors. This method could also be used for measurement in accelerators or fusion reactors.

  9. Transmutation detectors

    International Nuclear Information System (INIS)

    Viererbl, L.; Lahodova, Z.; Klupak, V.; Sus, F.; Kucera, J.; Kus, P.; Marek, M.

    2011-01-01

    We have designed a new type of detectors, called transmutation detectors, which can be used primarily for neutron fluence measurement. The transmutation detector method differs from the commonly used activation detector method in evaluation of detector response after irradiation. Instead of radionuclide activity measurement using radiometric methods, the concentration of stable non-gaseous nuclides generated by transmutation in the detector is measured using analytical methods like mass spectrometry. Prospective elements and nuclear reactions for transmutation detectors are listed and initial experimental results are given. The transmutation detector method could be used primarily for long-term measurement of neutron fluence in fission nuclear reactors, but in principle it could be used for any type of radiation that can cause transmutation of nuclides in detectors. This method could also be used for measurement in accelerators or fusion reactors.

  10. Shock-resistant scintillation detector

    International Nuclear Information System (INIS)

    Novak, W.P.

    1979-01-01

    A unique scintillation detector unit is disclosed which employs a special light transfer and reflector means that encases and protects the scintillator crystal against high g forces. The light transfer means comprises a flexible silicon rubber optical material bonded between the crystal and the optical window and having an axial thickness sufficient to allow the scintillator to move axially inside the container under high g forces without destroying the bonds. The reflector means comprises a soft elastic silicone rubber sleeve having a multiplicity of closely arranged tapered protrusions radiating toward and engaging the periphery of the scintillator crystal to cushion shocks effectively and having a reflective material, such as aluminum oxide powder, in the spaces between the protrusions. The reflector means provides improved shock absorption because of the uniform support and cushioning action of the protrusions and also provides the detector with high efficiency. The silicon rubber composition is specially compounded to include a large amount of aluminum oxide which enables the rubber to function effectively as a light reflector

  11. LHC luminosity upgrade detector challenges

    CERN Multimedia

    CERN. Geneva; de Roeck, Albert; Bortoletto, Daniela; Wigmans, Richard; Riegler, Werner; Smith, Wesley H

    2006-01-01

    LHC luminosity upgrade: detector challenges The upgrade of the LHC machine towards higher luminosity (1035 cm -2s-1) has been studied over the last few years. These studies have investigated scenarios to achieve the increase in peak luminosity by an order of magnitude, as well as the physics potential of such an upgrade and the impact of a machine upgrade on the LHC DETECTORS. This series of lectures will cover the following topics: • Physics motivation and machine scenarios for an order of magnitude increase in the LHC peak luminosity (lecture 1) • Detector challenges including overview of ideas for R&D programs by the LHC experiments: tracking and calorimetry, other new detector developments (lectures 2-4) • Electronics, trigger and data acquisition challenges (lecture 5) Note: the much more ambitious LHC energy upgrade will not be covered

  12. Application of cadmium telluride detectors to high energy computed tomography

    International Nuclear Information System (INIS)

    Glasser, F.; Thomas, G.; Cuzin, M.; Verger, L.

    1991-01-01

    15 years ago, Cadmium Telluride detectors have been investigated in our laboratory as possible detectors for medical scanners [1]. Today most of these machines are using high pressure Xenon gas as multicells detectors, BGO or CdWO 4 scintillators for industrial computerized tomography. Xenon gas detectors are well suited for detection of 100 KeV X-rays and enables to build 1000 cells homogeneous detector with a dynamic range of 3 decades. BGO and CdWO 4 scintillators, associated with photomultipliers or photodiodes are used for higher energy (400 KeV). They present a low afterglow and a dynamic range of 4 to 5 decades. Non destructive testing of very absorbing objects (eg 2 m diameter solid rocket motor) by X-ray tomography requires much higher energy X-rays (16 MeV) and doses up to 12000 rads/min at 1 meter. For this application Cadmium Telluride detectors operating as photoconductors are well suited. A prototype of tomograph machine, able to scan 0.5 m diameter high density objects has been realized with 25 CdTe detectors (25x15x0.8 mm 3 ). It produces good quality 1024x1024 tomographic images

  13. Synchrotron radiation and multichannel detectors in structural analysis

    Energy Technology Data Exchange (ETDEWEB)

    Mokulskii, M

    1979-10-01

    A survey is presented of the development of multichannel synchrotron X radiation detectors for the structural analysis of crystals. Tests are currently under way of a 4-thousand-channel plane detector of soft X radiation. The detector consists of a multiwire proportional counter using argon and CO/sub 2/ as the working gases. The detector is coupled to a computer processing information and displaying the respective X-ray diffraction images on the monitor. The described equipment allows imaging, eg., the cross section of the elementary cell of a DNA crystal. A 16-thousand-channel detector exists in the present time and the building is envisaged of a detector with 65 thousand channels.

  14. Synchrotron radiation and multichannel detectors in structural analysis

    International Nuclear Information System (INIS)

    Mokulskij, M.

    1979-01-01

    A survey is presented of the development of multichannel synchrotron X radiation detectors for the structural analysis of crystals. Tests are currently under way of a 4-thousand-channel plane detector of soft X radiation. The detector consists of a multiwire proportional counter using argon and CO 2 as the working gases. The detector is coupled to a computer processing information and displaying the respective X-ray diffraction images on the monitor. The described equipment allows imaging, eg., the cross section of the elementary cell of a DNA crystal. A 16-thousand-channel detector exists in the present time and the building is envisaged of a detector with 65 thousand channels. (J.B.)

  15. Detectors for Linear Colliders: Tracking and Vertexing (2/4)

    CERN Multimedia

    CERN. Geneva

    2010-01-01

    Efficient and precise determination of the flavour of partons in multi-hadron final states is essential to the anticipated LC physics program. This makes tracking in the vicinity of the interaction region of great importance. Tracking extrapolation and momentum resolution are specified by precise physics requirements. The R&D towards detectors able to meet these specifications will be discussed, together with some of their application beyond particle physics.

  16. Effect of intensifying screens to subject contrast

    International Nuclear Information System (INIS)

    Lee, In Ja; Huh, Joon; Kang, Hong Seok; Yoon, Chul Ho

    1990-01-01

    It is an experimental report about object contrast according to the Kinds of screen and obtained results as follows ; 1. In the same object radiography, use acquired the difference of the object contrast between LT-II(CaWO 4 system) and G4(Gd system) screens. 2. object contrast more decreased in Gd system screen than CaWO 4 and object contrast controlled by X-ray tube voltage. 3. The difference of object contrast seen clearly in 80 kVp

  17. The ALICE Silicon Pixel Detector System (SPD)

    CERN Document Server

    Kluge, A; Antinori, Federico; Burns, M; Cali, I A; Campbell, M; Caselle, M; Ceresa, S; Dima, R; Elias, D; Fabris, D; Krivda, Marian; Librizzi, F; Manzari, Vito; Morel, M; Moretto, Sandra; Osmic, F; Pappalardo, G S; Pepato, Adriano; Pulvirenti, A; Riedler, P; Riggi, F; Santoro, R; Stefanini, G; Torcato De Matos, C; Turrisi, R; Tydesjo, H; Viesti, G; PH-EP

    2007-01-01

    The ALICE silicon pixel detector (SPD) comprises the two innermost layers of the ALICE inner tracker system. The SPD includes 120 detector modules (half-staves) each consisting of 10 ALICE pixel chips bump bonded to two silicon sensors and one multi-chip read-out module. Each pixel chip contains 8192 active cells, so that the total number of pixel cells in the SPD is ≈ 107. The on-detector read-out is based on a multi-chip-module containing 4 ASICs and an optical transceiver module. The constraints on material budget and detector module dimensions are very demanding.

  18. Detector Control System for the ATLAS Forward Proton detector

    CERN Document Server

    Czekierda, Sabina; The ATLAS collaboration

    2017-01-01

    The ATLAS Forward Proton (AFP) is a forward detector using a Roman Pot technique, recently installed in the LHC tunnel. It is aiming at registering protons that were diffractively or electromagnetically scattered in soft and hard processes. Infrastructure of the detector consists of hardware placed both in the tunnel and in the control room USA15 (about 330 meters from the Roman Pots). AFP detector, like the other detectors of the ATLAS experiment, uses the Detector Control System (DCS) to supervise the detector and to ensure its safe and coherent operation, since the incorrect detector performance may influence the physics results. The DCS continuously monitors the detector parameters, subset of which is stored in data bases. Crucial parameters are guarded by alarm system. A detector representation as a hierarchical tree-like structure of well-defined subsystems built with the use of the Finite State Machine (FSM) toolkit allows for overall detector operation and visualization. Every node in the hierarchy is...

  19. Particle tracking at 4K: The Fast Annihilation Cryogenic Tracking (FACT) detector for the AEgIS antimatter gravity experiment

    CERN Document Server

    Storey, J; Ahlén, O; Amsler, C; Ariga, A; Ariga, T; Belov, A.S; Bonomi, G; Bräunig, P; Bremer, J; Brusa, R.S; Burghart, G; Cabaret, L; Canali, C; Carante, M; Caravita, R; Castelli, F; Cerchiari, G; Cialdi, S; Comparat, D; Consolati, G; Dassa, L; Di Domizio, S; Di Noto, L; Doser, M; Dudarev, A; Ereditato, A; Ferragut, R; Fontana, A; Genova, P; Giammarchi, M; Gligorova, A; Gninenko, S.N; Haider, S; Hogan, S.D; Huse, T; Jordan, E; Jørgensen, L.V; Kaltenbacher, T; Kawada, J; Kellerbauer, A; Kimura, M; Knecht, A; Krasnický, D; Lagomarsino, V; Magnani, A; Mariazzi, S; Matveev, V.A; Merkt, F; Moia, F; Nebbia, G; Nédélec, P; Oberthaler, M.K; Pacifico, N; Petrácek, V; Pistillo, C; Prelz, F; Prevedelli, M; Regenfus, C; Riccardi, C; Røhne, O; Rotondi, A; Sandaker, H; Scampoli, P; Spacek, M; Subieta Vasquez, M.A; Testera, G; Trezzi, D; Vaccarone, R; Zavatarelli, S

    2013-01-01

    The AEgIS experiment is an international collaboration with the main goal of performing the fi rst direct measurement of the Earth ' s gravitational acceleration on antimatter. Critical to the success of AEgIS is the production of cold antihydrogen ( H) atoms. The FACT detector is used to measure the production and temperature of the H atoms and for establishing the formation of a H beam. The operating requirements for this detector are very challenging: it must be able to identify each of the thousand or so annihilations in the 1 ms period of pulsed H production, operate at 4 K inside a 1 T solenoidal fi eld and not produce more than 10 W of heat. The FACT detector consists of two concentric cylindrical layers of 400 scintillator fi bres with a 1 mm diameter and a 0.6 mm pitch. The scintillating fi bres are coupled to clear fi bres which transport the scintillation light to 800 silicon photomultipliers. Each silicon photomultiplier signal is connected to a linear ampli fi er and a fast discriminator, the out...

  20. Position sensitive detector for X-ray photons

    International Nuclear Information System (INIS)

    Barbosa, A.F.

    1988-01-01

    This work reports the theoretical basis and the details of the construction process, characterization and application of gas X-ray position sensitive detectors. The unidimensional detector consists of a gas camera (argon and CH 4 ), a metallic anode, a cathode and a delay line. Details of the construction process are given in order to allow the reproduction of the detector. It has been characterized by measuring its spatial resolution, homogeneity and linerity. The built linear detector has been used to obtain diffraction diagrams from polycrystalline silicon, C 23 H 48 paraffin and glassy carbon. These diagrams have been compared with those obtained under equivalent conditions with a conventional proportional detector by the step scanning method. It has been shown that the detector provides diffraction diagrams of equivalent quality to those obtained by the step scanning method, in appreciably lower time intervals. (author) [pt

  1. Interfacial reaction in SiC_f/Ti-6Al-4V composite by using transmission electron microscopy

    International Nuclear Information System (INIS)

    Huang, Bin; Li, Maohua; Chen, Yanxia; Luo, Xian; Yang, Yanqing

    2015-01-01

    The interfacial reactions of continuous SiC fiber reinforced Ti-6Al-4V matrix composite (SiC_f/Ti-6Al-4V composite) and continuous SiC fiber coated by C reinforced Ti-6Al-4V matrix composite (SiC_f/C/Ti-6Al-4V composite) were investigated by using micro-beam electron diffraction (MBED) and energy disperse spectroscopy (EDS) on transmission electron microscopy (TEM). The sequence of the interfacial reactions in the as-processed and exposed at 900°C for 50h SiC_f/Ti-6Al-4V composites can be described as SiC||TiC||Ti_5Si_3 + TiC||Ti-6Al-4V and SiC||TiC||Ti_5Si_3||TiC||Ti_5Si_3||TiC||Ti_5Si_3||Ti-6Al-4V, respectively. Additionally, both in as-processed and exposed composites, Ti_3SiC_2 and Ti_3Si are absent at the interfaces. For the SiC_f/C/Ti-6Al-4V composite exposed at 900 °C for 50 h, the sequence of the interfacial reaction can be described as SiC||C||TiC_F||TiC_C||Ti-6Al-4V before C coating is completely consumed by interfacial reaction. When interfacial reaction consumes C coating completely, the sequence of the interfacial reaction can be described as SiC||TiC||Ti_5Si_3||TiC||Ti-6Al-4V. Furthermore, in SiC_f/C/Ti-6Al-4V composite, C coating can absolutely prevent Si diffusion from SiC fiber to matrix. Basing on these results, the model of formation process of the interfacial reaction products in the composites was proposed. - Highlights: • We obtained the sequence of the interfacial reactions in the as-processed and exposed at 900 °C for 50 h SiC_f/Ti-6Al-4 V composites as well as in the SiC_f/C/Ti-6Al-4 V composite exposed at 900 °C for 50 h. • We verified that both in as-processed and exposed SiC_f/Ti-6Al-4 V composites, Ti_3SiC_2 and Ti_3Si are absent at the interfaces. • Carbon coating can absolutely prevent silicon diffusion from SiC fiber to matrix. • Basing on these results, the model of formation process of the interfacial reaction products in the composites was proposed.

  2. Renal stone characterization using high resolution imaging mode on a photon counting detector CT system

    Science.gov (United States)

    Ferrero, A.; Gutjahr, R.; Henning, A.; Kappler, S.; Halaweish, A.; Abdurakhimova, D.; Peterson, Z.; Montoya, J.; Leng, S.; McCollough, C.

    2017-03-01

    In addition to the standard-resolution (SR) acquisition mode, a high-resolution (HR) mode is available on a research photon-counting-detector (PCD) whole-body CT system. In the HR mode each detector consists of a 2x2 array of 0.225 mm x 0.225 mm subpixel elements. This is in contrast to the SR mode that consists of a 4x4 array of the same subelements, and results in 0.25 mm isotropic resolution at iso-center for the HR mode. In this study, we quantified ex vivo the capabilities of the HR mode to characterize renal stones in terms of morphology and mineral composition. Forty pure stones - 10 uric acid (UA), 10 cystine (CYS), 10 calcium oxalate monohydrate (COM) and 10 apatite (APA) - and 14 mixed stones were placed in a 20 cm water phantom and scanned in HR mode, at radiation dose matched to that of routine dual-energy stone exams. Data from micro CT provided a reference for the quantification of morphology and mineral composition of the mixed stones. The area under the ROC curve was 1.0 for discriminating UA from CYS, 0.89 for CYS vs COM and 0.84 for COM vs APA. The root mean square error (RMSE) of the percent UA in mixed stones was 11.0% with a medium-sharp kernel and 15.6% with the sharpest kernel. The HR showed qualitatively accurate characterization of stone morphology relative to micro CT.

  3. Detection of dopamine in non-treated urine samples using glassy carbon electrodes modified with PAMAM dendrimer-Pt composites

    International Nuclear Information System (INIS)

    Garcia, M.G.; Armendariz, G.M.E.; Godinez, Luis A.; Torres, J.; Sepulveda-Guzman, S.; Bustos, E.

    2011-01-01

    Composites of hydroxyl-terminated PAMAM dendrimers, generation 4.0 (64 peripheral OH groups) containing Pt nanoparticles were synthesized at different reaction times using a microwave reactor. The synthetic procedure resulted in dendrimer encapsulated nanoparticles of Pt (DENs-Pt) of 1.53 ± 0.17 nm diameter that was calculated from transmission electron microscopy, and the Pt nanoparticles had single crystal plane in (1 1 1) orientation determinate by selective area diffraction. Each composite was electrochemically immobilized on a pre-functionalized glassy carbon (GC) electrode that was incorporated as a flow injection amperometric (FIA) detector, for the selective detection and quantification of dopamine (DA) in untreated urine samples. Comparison of the analytical performance of the novel electrochemical detector revealed that the DENs-Pt modified GC electrode with the composite synthesized for 30 min in the microwave reactor, showed the best response for the detection of DA in samples of non-treated urine, being the detection and quantification limits smaller (19 and 9 ppb, respectively) than those corresponding to the naked a GC electrode (846 and 423 ppb, respectively) using the FIA detector. In addition, it was found that this electroanalytical approach suffers minimal matrix effects that arise in the analysis of DA in untreated samples of urine.

  4. Detection of dopamine in non-treated urine samples using glassy carbon electrodes modified with PAMAM dendrimer-Pt composites

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, M.G. [Laboratory of Bioelectrochemistry, Centro de Investigacion y Desarrollo Tecnologico en Electroquimica, S. C., Parque Tecnologico, Queretaro, Sanfandila, Pedro Escobedo 76703, Queretaro (Mexico); Department of Chemistry, Universidad de Guanajuato, Cerro de la Venada S/N Col. Pueblito de Rocha, 36040 Guanajuato, Gto (Mexico); Armendariz, G.M.E.; Godinez, Luis A.; Torres, J. [Laboratory of Bioelectrochemistry, Centro de Investigacion y Desarrollo Tecnologico en Electroquimica, S. C., Parque Tecnologico, Queretaro, Sanfandila, Pedro Escobedo 76703, Queretaro (Mexico); Sepulveda-Guzman, S. [Centro de Innovacion, Investigacion y Desarrollo en Ingenieria y Tecnologia, Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon, Av. Universidad, San Nicolas de los Garza, Nuevo Leon, 66451 Nuevo Leon (Mexico); Bustos, E., E-mail: ebustos@cideteq.mx [Laboratory of Bioelectrochemistry, Centro de Investigacion y Desarrollo Tecnologico en Electroquimica, S. C., Parque Tecnologico, Queretaro, Sanfandila, Pedro Escobedo 76703, Queretaro (Mexico)

    2011-09-01

    Composites of hydroxyl-terminated PAMAM dendrimers, generation 4.0 (64 peripheral OH groups) containing Pt nanoparticles were synthesized at different reaction times using a microwave reactor. The synthetic procedure resulted in dendrimer encapsulated nanoparticles of Pt (DENs-Pt) of 1.53 {+-} 0.17 nm diameter that was calculated from transmission electron microscopy, and the Pt nanoparticles had single crystal plane in (1 1 1) orientation determinate by selective area diffraction. Each composite was electrochemically immobilized on a pre-functionalized glassy carbon (GC) electrode that was incorporated as a flow injection amperometric (FIA) detector, for the selective detection and quantification of dopamine (DA) in untreated urine samples. Comparison of the analytical performance of the novel electrochemical detector revealed that the DENs-Pt modified GC electrode with the composite synthesized for 30 min in the microwave reactor, showed the best response for the detection of DA in samples of non-treated urine, being the detection and quantification limits smaller (19 and 9 ppb, respectively) than those corresponding to the naked a GC electrode (846 and 423 ppb, respectively) using the FIA detector. In addition, it was found that this electroanalytical approach suffers minimal matrix effects that arise in the analysis of DA in untreated samples of urine.

  5. Study of the effect of the misalignment of the muon detectors at the ATLAS experiment on the discovery of the Higgs particle H->4mu

    CERN Document Server

    Stefanidis, E

    2003-01-01

    The ATLAS (A Toroidal LHC ApparatuS) detector is one of the four detectors which will be installed in the new accelerator, at LHC, CERN. One of the experiments' research aims is the discovery of the Higgs particle and thus, the confirmation or not of the Standard Model. The Muon Spectrometer of the detector has special importance, because the decay channels of the Higgs particle which have muons at the final state are clear signatures of the existence of the Higgs particle. This project focuses on the Higgs decay through the channel: H->ZZ->4mu. The alignment of the muon detectors has to be very accurate, so that its contribution on the measurement of the muons' momentum, to be low compared to the intrinsic resolution of the detectors themselves. Although the alignment of the muons detectors at the barrel and the end-caps regions is well controlled, the relative alignment of the end-caps with respect to barrel is not controlled with the same accuracy. In this project, we study the influence of such misalignme...

  6. Systematic study of Si-based GeSn photodiodes with 2.6 µm detector cutoff for short-wave infrared detection.

    Science.gov (United States)

    Pham, Thach; Du, Wei; Tran, Huong; Margetis, Joe; Tolle, John; Sun, Greg; Soref, Richard A; Naseem, Hameed A; Li, Baohua; Yu, Shui-Qing

    2016-03-07

    Normal-incidence Ge 1-x Sn x photodiode detectors with Sn compositions of 7 and 10% have been demonstrated. Such detectors were based on Ge/Ge 1-x Sn x /Ge double heterostructures grown directly on a Si substrate via a chemical vapor deposition system. A temperature-dependence study of these detectors was conducted using both electrical and optical characterizations from 300 to 77 K. Spectral response up to 2.6 µm was achieved for a 10% Sn device at room temperature. The peak responsivity and specific detectivity (D*) were measured to be 0.3 A/W and 4 × 10 9 cmHz 1/2 W -1 at 1.55 µm, respectively. The spectral D* of a 7% Sn device at 77 K was only one order-of-magnitude lower than that of an extended-InGaAs photodiode operating in the same wavelength range, indicating the promising future of GeSn-based photodetectors.

  7. Melting Behavior and Thermolysis of NaBH4−Mg(BH42 and NaBH4−Ca(BH42 Composites

    Directory of Open Access Journals (Sweden)

    Morten B. Ley

    2015-04-01

    Full Text Available The physical properties and the hydrogen release of NaBH4–Mg(BH42 and NaBH4−Ca(BH42 composites are investigated using in situ synchrotron radiation powder X-ray diffraction, thermal analysis and temperature programmed photographic analysis. The composite, xNaBH4–(1 − xMg(BH42, x = 0.4 to 0.5, shows melting/frothing between 205 and 220 °C. However, the sample does not become a transparent molten phase. This behavior is similar to other alkali-alkaline earth metal borohydride composites. In the xNaBH4–(1 − xCa(BH42 system, eutectic melting is not observed. Interestingly, eutectic melting in metal borohydrides systems leads to partial thermolysis and hydrogen release at lower temperatures and the control of sample melting may open new routes for obtaining high-capacity hydrogen storage materials.

  8. Obtaining muonic density estimates via application of matrix formalism to proposed surface detector upgrade at the Pierre Auger Observatory

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, David; Engel, Ralph; Roth, Markus [Karlsruhe Institute of Technology, Karlsruhe (Germany); Collaboration: Pierre Auger-Collaboration

    2015-07-01

    Event-by-event identification of cosmic ray primary composition lends itself to enhanced event selection in the search for anisotropic arrival directions. Principally, the number of muons reaching Earth's surface in an extensive air shower is indicative of composition. The Pierre Auger Observatory seeks to capitalize on this axiom by improving reconstructed muonic density estimates via an upgrade to its surface detector array. This upgrade, consisting of placing a scintillator on top of each existing water Cherenkov detector, exploits the differing response of two detectors to muonic and electromagnetic particles. Exploitation of this difference may be expressed in a matrix formalism whose application to simulated proton and iron showers is presented here.

  9. Improved Charge Separation in WO3/CuWO4 Composite Photoanodes for Photoelectrochemical Water Oxidation

    Directory of Open Access Journals (Sweden)

    Danping Wang

    2016-05-01

    Full Text Available Porous tungsten oxide/copper tungstate (WO3/CuWO4 composite thin films were fabricated via a facile in situ conversion method, with a polymer templating strategy. Copper nitrate (Cu(NO32 solution with the copolymer surfactant Pluronic®F-127 (Sigma-Aldrich, St. Louis, MO, USA, generic name, poloxamer 407 was loaded onto WO3 substrates by programmed dip coating, followed by heat treatment in air at 550 °C. The Cu2+ reacted with the WO3 substrate to form the CuWO4 compound. The composite WO3/CuWO4 thin films demonstrated improved photoelectrochemical (PEC performance over WO3 and CuWO4 single phase photoanodes. The factors of light absorption and charge separation efficiency of the composite and two single phase films were investigated to understand the reasons for the PEC enhancement of WO3/CuWO4 composite thin films. The photocurrent was generated from water splitting as confirmed by hydrogen and oxygen gas evolution, and Faradic efficiency was calculated based on the amount of H2 produced. This work provides a low-cost and controllable method to prepare WO3-metal tungstate composite thin films, and also helps to deepen the understanding of charge transfer in WO3/CuWO4 heterojunction.

  10. Design and test results of the AMS RICH detector

    CERN Document Server

    Casadei, D.

    2002-01-01

    The AMS-02 detector will operate for at least 3 years on the International Space Station, measuring cosmic ray spectra at about 400 km above sea level over a wide range of geomagnetic latitude. The proximity focusing ring imaging \\v{C}erenkov counter of AMS-02 will measure the particle velocity $\\beta$ with $\\approx 0.1%$ uncertainty, making possible to discriminate Beryllium isotopes up to about 15 GeV/nucl. In addition its charge measurement will allow to study the elemental composition of cosmic rays up to Iron. A prototype of the RICH detector was tested with cosmic rays and on a ion beam accelerated by SPS, at CERN (October 2002).

  11. The Saskatchewan-Alberta large acceptance detector for photonuclear physics

    Science.gov (United States)

    Cairns, E. B.; Cameron, J.; Choi, W. C.; Fielding, H. W.; Green, P. W.; Greeniaus, L. G.; Hackett, E. D.; Holm, L.; Kolb, N. R.; Korkmaz, E.; Langill, P. P.; McDonald, W. J.; Mack, D.; Olsen, W. C.; Peterson, B. A.; Rodning, N. L.; Soukup, J.; Zhu, J.; Hutcheon, D.; Caplan, H. S.; Pywell, R. E.; Skopik, D. M.; Vogt, J. M.; van Heerden, I. J.

    1992-09-01

    The Saskatchewan-Alberta Large Acceptance Detector (SALAD) is a 4 π detector designed and built for studies of photonuclear reactions with a tagged photon beam. The design and performance of the detector are described. Its characteristics have been studied by examining p-p elastic scattering with a proton beam at TRIUMF.

  12. Detectors and focal plane modules for weather satellites

    Science.gov (United States)

    D'Souza, A. I.; Robinson, E.; Masterjohn, S.; Ely, P.; Khalap, V.; Babu, S.; Smith, D. S.

    2016-05-01

    Weather satellite instruments require detectors with a variety of wavelengths ranging from the visible to VLWIR. One of the remote sensing applications is the geostationary GOES-ABI imager covering wavelengths from the 450 to 490 nm band through the 13.0 to 13.6 μm band. There are a total of 16 spectral bands covered. The Cross-track infrared Sounder (CrIS) is a Polar Orbiting interferometric sensor that measures earth radiances at high spectral resolution, using the data to provide pressure, temperature and moisture profiles of the atmosphere. The pressure, temperature and moisture sounding data are used in weather prediction models that track storms, predict levels of precipitation etc. The CrIS instrument contains SWIR (λc ~ 5 μm at 98K), MWIR (λc ~ 9 μm at 98K) and LWIRs (λc ~ 15.5 μm at 81K) bands in three Focal Plane Array Assemblies (FPAAs). GOES-ABI contains three focal plane modules (FPMs), (i) a visible-near infrared module consisting of three visible and three near infrared channels, (ii) a MWIR module comprised of five channels from 3.9 μm to 8.6 μm and (iii) a 9.6 μm to 13.3 μm, five-channel LWIR module. The VNIR FPM operates at 205 K, and the MWIR and LWIR FPMs operate at 60 K. Each spectral channel has a redundant array built into a single detector chip. Switching is thus permitted from the primary selected array in each channel to the redundant array, given any degradation in performance of the primary array during the course of the mission. Silicon p-i-n detectors are used for the 0.47 μm to 0.86 μm channels. The thirteen channels above 1 μm are fabricated in various compositions of Hg1-xCdxTe, and in this particular case using two different detector architectures. The 1.38 μm to 9.61 μm channels are all fabricated in Hg1-xCdxTe grown by Liquid Phase Epitaxy (LPE) using the HDVIP detector architecture. Molecular beam epitaxy (MBE)-grown Hg1-xCdxTe material are used for the LWIR 10.35 μm to 13.3 μm channels fabricated in Double

  13. An arc detector for neutron crystal structure investigations

    Energy Technology Data Exchange (ETDEWEB)

    Habib, N [Reactor and Neutron Physics Dept., Nuclear Research Center. AEA, Cairo (Egypt)

    1997-12-31

    An arc detector for neutron structure investigations of powder crystals using time-of-flight technique is described. In order to enable the measurement of integral intensity from about 1/4 of the Debye-Scherrer ring and for simplicity reasons, the scattering angle 20-90 degree was chosen and a special arc collimator was built. The arc collimator-detector had a divergency of about 20 minutes of arc, and the distance between detector-sample was 64 cm. Four {sup 3} He detectors were fixed on the arc of the collimator. Both efficiency and space sensitivity of the detector were determined using a point neutron source. Results of measurements show that parameters of the arc detector are acceptable for high resolution crystal structure investigations. 6 figs.

  14. Department of Radiation Detectors: Overview

    International Nuclear Information System (INIS)

    Piekoszewski, J.

    1999-01-01

    Full text: Work carried out in 1998 in the Department of Radiation Detectors concentrated on three subjects: (i) Semiconductor Detectors (ii) X-ray Tube Generators (iii) Material Modification Using Ion and Plasma Beams. SEMICONDUCTOR DETECTORS: Semiconductor detectors of ionizing radiation are among the basic tools utilized in such fields of research and industry as nuclear physics, high energy physics, medical (oncology) radiotherapy, radiological protection, environmental monitoring, energy dispersive X-ray fluorescence non-destructive analysis of chemical composition, nuclear power industry. The departmental objectives are: a search for new types of detectors; producing unique detectors tailored for physics experiments; manufacturing standard detectors for radiation measuring instruments; scientific development of the staff. These objectives were accomplished in 1998 particularly by: research on unique thin silicon detectors for identification of particles in E-ΔE telescopes, modernization of technology of manufacturing Ge(Li) detectors capable of detecting broader range of gamma energies, manufacturing detectors developed in previous years, re-generating and servicing customer detectors of various origin. In accomplishment of the above the Department co-operated with groups of physicists from IPJ, PAN Institute of Physics (Warsaw), and with some technology Institutes based in Warsaw (ITME, ITE). Some detectors and services have been delivered to customers on a commercial basis. X-Ray TUBE GENERATORS: The Department conducts research on design and technology of manufacturing X-ray generators as well as on imaging and dosimetry of X-ray beams. Various models of special construction X-ray tubes and their power supplies are under construction. In 1998 work concentrated on: completing laboratory equipment for manufacturing X-ray tubes and their components, developing technology of manufacturing X-ray tubes and their components, completing a laboratory set-up with

  15. The WASA detector at CELSIUS

    International Nuclear Information System (INIS)

    Bilger, R.; Blom, M.; Bogoslawsky, D.; Bondar, A.; Brodowski, W.; Calen, H.; Chuvilo, I.; Clement, H.; Dunin, V.; Dyring, J.; Ekstroem, C.; Fransson, K.; Friden, C-J.; Gustafsson, L.; Haeggstroem, S.; Hoeistad, B.; Jacewicz, M.; Johanson, J.; Johansson, A.; Johansson, T.; Khoukaz, A.; Kilian, K.; Kimura, N.; Koch, I.; Kolachev, G.; Komogorov, M.; Kullander, S.; Kupsc, A.; Kurdadze, L.; Kuzmin, A.; Kuznetsov, A.; Marciniewski, P.; Martemyanov, A.; Martemyanov, B.; Morosov, B.; Moertsell, A.; Nawrot, A.; Oelert, W.; Oreshkin, S.; Petukhov, Y.; Povtorejko, A.; Przestrzelska, K.; Paetzold, J.; Reistad, D.; Ruber, R.J.M.Y.; Sandukovsky, V.; Schuberth, U.; Sefzick, T.; Sidorov, V.; Shwartz, B.; Sopov, V.; Stepaniak, J.; Sukhanov, A.; Sukhanov, A.; Sundberg, P.; Tchernychev, V.; Tikhomirov, V.; Turowiecki, A.; Wagner, G.; Wilhelmi, Z.; Yamamoto, A.; Yamaoka, H.; Zabierowski, J.; Zernov, A.; Zlomanczuk, J.

    2000-01-01

    The assembly of the WASA 4π detector at the The Svedberg Laboratory in Uppsala is now completed. The superconducting solenoid, the vacuum chambers and all of the sensitive parts of the detector have been installed at the CELSIUS accelerator and storage ring. The pellet generator, providing internal hydrogen (and deuterium) targets, has been installed on top of WASA. The first test run together with the CELSIUS proton beam was carried through in May 1999

  16. Preparation and photoelectric properties of p-CaFe2O4/n-WO3 composites

    International Nuclear Information System (INIS)

    Wan, Ruiqin; Jia, Caihong; Zhang, Weifeng

    2012-01-01

    Highlights: ► Surface photovoltage spectroscopy investigation on p-CaFe 2 O 4 /n-WO 3 composites. ► The photovoltaic response is enhanced in p-CaFe 2 O 4 /n-WO 3 composites. ► The multielectron process and high rate of carrier migration in WO 3 . - Abstract: Composites of p-CaFe 2 O 4 /n-WO 3 are prepared via a sol–gel technique. Their structures and optical properties are characterized with X-ray diffraction, scanning electron microscopy and UV–vis absorption spectroscopy. The photoelectric characteristics are investigated by surface photovoltage spectroscopy combined with electric field induced surface photovoltage spectroscopy. The results indicate that CaFe 2 O 4 can well form a p–n type composite with WO 3 , and the intensity and spectral region of surface photovoltaic response for the composites are strongly dependent on the molar ratio of two components. The enhancement in photoelectric properties and the effective separation of photogenerated carriers could be attributed to the energy level matching between the two components, multielectron process and the high migration rate in WO 3 .

  17. Mechanical Properties and Thermal Shock Resistance Analysis of BNNT/Si3N4 Composites

    Science.gov (United States)

    Wang, Shouren; Wang, Gaoqi; Wen, Daosheng; Yang, Xuefeng; Yang, Liying; Guo, Peiquan

    2018-04-01

    BNNT/Si3N4 ceramic composites with different weight amount of BNNT fabricated by hot isostatic pressing were introduced. The mechanical properties and thermal shock resistance of the composites were investigated. The results showed that BNNT-added ceramic composites have a finer and more uniform microstructure than that of BNNT-free Si3N4 ceramic because of the retarding effect of BNNT on Si3N4 grain growth. The addition of 1.5 wt.% BNNT results in simultaneous increase in flexural strength, fracture toughness, and thermal shock resistance. The analysis of the results indicates that BNNT brings many thermal transport channels in the microstructure, increasing the efficiency of thermal transport, therefore results in increase of thermal shock resistance. In addition, BNNT improves the residual flexural strength of composites by crack deflection, bridging, branching and pinning, which increase the crack propagation resistance.

  18. Nanophosphor composite scintillators comprising a polymer matrix

    Science.gov (United States)

    Muenchausen, Ross Edward; Mckigney, Edward Allen; Gilbertson, Robert David

    2010-11-16

    An improved nanophosphor composite comprises surface modified nanophosphor particles in a solid matrix. The nanophosphor particle surface is modified with an organic ligand, or by covalently bonding a polymeric or polymeric precursor material. The surface modified nanophosphor particle is essentially charge neutral, thereby preventing agglomeration of the nanophosphor particles during formation of the composite material. The improved nanophosphor composite may be used in any conventional scintillator application, including in a radiation detector.

  19. The NA49 large acceptance hadron detector

    International Nuclear Information System (INIS)

    Afanasiev, S.; Alber, T.; Appelshaeuser, H.; Baechler, J.; Barna, D.; Barnby, L.S.; Bartke, J.; Barton, R.A.; Betev, L.; Bialkowska, H.; Bieser, F.; Billmeier, A.; Blyth, C.O.; Bock, R.; Bormann, C.; Bracinik, J.; Brady, F.P.; Brockmann, R.; Brun, R.; Buncic, P.; Caines, H.L.; Cebra, D.; Cooper, G.E.; Cramer, J.G.; Csato, P.; Cyprian, M.; Dunn, J.; Eckardt, V.; Eckhardt, F.; Empl, T.; Eschke, J.; Ferguson, M.I.; Fessler, H.; Fischer, H.G.; Flierl, D.; Fodor, Z.; Frankenfeld, U.; Foka, P.; Freund, P.; Friese, V.; Ftacnik, J.; Fuchs, M.; Gabler, F.; Gal, J.; Ganz, R.; Gazdzicki, M.; Gladysz, E.; Grebieszkow, J.; Guenther, J.; Harris, J.W.; Hegyi, S.; Henkel, T.; Hill, L.A.; Hlinka, V.; Huang, I.; Huemmler, H.; Igo, G.; Irmscher, D.; Ivanov, M.; Janik, R.; Jacobs, P.; Jones, P.G.; Kadija, K.; Kolesnikov, V.I.; Kowalski, M.; Lasiuk, B.; Levai, P.; Liebicher, K.; Lynen, U.; Malakhov, A.I.; Margetis, S.; Markert, C.; Marks, C.; Mayes, B.; Melkumov, G.L.; Mock, A.; Molnar, J.; Nelson, J.M.; Oldenburg, M.; Odyniec, G.; Palla, G.; Panagiotou, A.D.; Pestov, Y.; Petridis, A.; Pikna, M.; Pimpl, W.; Pinsky, L.; Piper, A.; Porter, R.J.; Poskanzer, A.M.; Poziombka, S.; Prindle, D.J.; Puehlhofer, F.; Rauch, W.; Reid, J.G.; Renfordt, R.; Retyk, W.; Ritter, H.G.; Roehrich, D.; Roland, C.; Roland, G.; Rudolph, H.; Rybicki, A.; Sammer, T.; Sandoval, A.; Sann, H.; Schaefer, E.; Schmidt, R.; Schmischke, D.; Schmitz, N.; Schoenfelder, S.; Semenov, A.Yu.; Seyboth, J.; Seyboth, P.; Seyerlein, J.; Sikler, F.; Sitar, B.; Skrzypczak, E.; Squier, G.T.A.; Stelzer, H.; Stock, R.; Strmen, P.; Stroebele, H.; Struck, C.; Susa, T.; Szarka, I.; Szentpetery, I.; Szymanski, P.; Sziklai, J.; Toy, M.; Trainor, T.A.; Trentalange, S.; Ullrich, T.; Vassiliou, M.; Veres, G.; Vesztergombi, G.; Vranic, D.; Wang, F.Q.; Weerasundara, D.D.; Wenig, S.; Whitten, C.; Wieman, H.; Wienold, T.; Wood, L.; Yates, T.A.; Zimanyi, J.; Zhu, X.-Z.; Zybert, R.

    1999-01-01

    The NA49 detector is a wide acceptance spectrometer for the study of hadron production in p+p, p+A, and A+A collisions at the CERN SPS. The main components are 4 large-volume TPCs for tracking and particle identification via dE/dx. TOF scintillator arrays complement particle identification. Calorimeters for transverse energy determination and triggering, a detector for centrality selection in p+A collisions, and beam definition detectors complete the set-up. A description of all detector components is given with emphasis on new technical realizations. Performance and operational experience are discussed in particular with respect to the high track density environment of central Pb+Pb collisions

  20. The NA49 large acceptance hadron detector

    CERN Document Server

    Afanasiev, S V; Appelshäuser, H; Bächler, J; Barna, D; Barnby, L S; Bartke, Jerzy; Barton, R A; Betev, L; Bialkowska, H; Bieser, F; Billmeier, A; Blyth, C O; Böck, R K; Bormann, C; Bracinik, J; Brady, F P; Brockmann, R; Brun, R; Buncic, P; Caines, H L; Cebra, D; Cooper, G E; Cramer, J G; Csató, P; Cyprian, M; Dunn, J; Eckardt, V; Eckhardt, F; Empl, T; Eschke, J; Ferguson, M I; Fessler, H; Fischer, H G; Flierl, D; Fodor, Z; Frankenfeld, Ulrich; Foka, P Y; Freund, P; Friese, V; Ftácnik, J; Fuchs, M; Gabler, F; Gál, J; Ganz, R E; Gazdzicki, M; Gladysz-Dziadus, E; Grebieszkow, J; Günther, J; Harris, J W; Hegyi, S; Henkel, T; Hill, L A; Hlinka, V; Huang, I; Hümmler, H; Igo, G; Irmscher, D; Ivanov, M; Janik, R; Jacobs, P; Jones, P G; Kadija, K; Kolesnikov, V I; Kowalski, M; Lasiuk, B; Lévai, Peter; Liebicher, K; Lynen, U; Malakhov, A I; Margetis, S; Markert, C; Marks, C; Mayes, B W; Melkumov, G L; Mock, A; Molnár, J; Nelson, J M; Oldenburg, M; Odyniec, Grazyna Janina; Pálla, G; Panagiotou, A D; Pestov, Yu N; Petridis, A; Pikna, M; Pimpl, W; Pinsky, L; Piper, A; Porter, R J; Poskanzer, A M; Poziombka, S; Prindle, D J; Pühlhofer, F; Rauch, W; Reid, J G; Renfordt, R E; Retyk, W; Ritter, H G; Röhrich, D; Roland, C; Roland, G; Rudolph, H; Rybicki, A; Sammer, T; Sandoval, A; Sann, H; Schäfer, E; Schmidt, R; Schmischke, D; Schmitz, N; Schönfelder, S; Semenov, A Yu; Seyboth, J; Seyboth, P; Seyerlein, J; Siklér, F; Sitár, B; Skrzypczak, E; Squier, G T A; Stelzer, H; Stock, Reinhard; Strmen, P; Ströbele, H; Struck, C; Susa, T; Szarka, I; Szentpétery, I; Szymanski, P; Sziklai, J; Toy, M; Trainor, T A; Trentalange, S; Ullrich, T S; Vassiliou, Maria; Veres, G I; Vesztergombi, G; Vranic, D; Wang, F; Weerasundara, D D; Wenig, S; Whitten, C; Wieman, H H; Wienold, T; Wood, L; Yates, T A; Zimányi, J; Zhu, X Z; Zybert, R

    1999-01-01

    The NA49 detector is a wide acceptance spectrometer for the study of hadron production in p+p, p+A, and A+A collisions at the CERN SPS. The main components are 4 large volume TPCs for tracking and particle identification via $dE/dx$. TOF scintillator arrays complement particle identification. Calorimeters for transverse energy determination and triggering, a detector for centrality selection in p+A collisions, and beam definition detectors complete the set-up. A description of all detector components is given with emphasis on new technical realizations. Performance and operational experience are discussed in particular with respect to the high track density environment of central Pb+Pb collisions.

  1. The International Linear Collider Technical Design Report - Volume 4: Detectors

    CERN Document Server

    Behnke, Ties; Burrows, Philip N.; Fuster, Juan; Peskin, Michael; Stanitzki, Marcel; Sugimoto, Yasuhiro; Yamada, Sakue; Yamamoto, Hitoshi

    2013-01-01

    The International Linear Collider Technical Design Report (TDR) describes in four volumes the physics case and the design of a 500 GeV centre-of-mass energy linear electron-positron collider based on superconducting radio-frequency technology using Niobium cavities as the accelerating structures. The accelerator can be extended to 1 TeV and also run as a Higgs factory at around 250 GeV and on the Z0 pole. A comprehensive value estimate of the accelerator is give, together with associated uncertainties. It is shown that no significant technical issues remain to be solved. Once a site is selected and the necessary site-dependent engineering is carried out, construction can begin immediately. The TDR also gives baseline documentation for two high-performance detectors that can share the ILC luminosity by being moved into and out of the beam line in a "push-pull" configuration. These detectors, ILD and SiD, are described in detail. They form the basis for a world-class experimental programme that promises to incr...

  2. The pin detector - a simple, robust, cheap and effective nuclear radiation detector

    International Nuclear Information System (INIS)

    Bateman, J.E.

    1984-01-01

    The development of a series of radiation detectors bases on the point anode is reported. Using readily available preformed pins from a variety of electrical connectors as the anodes, a family of devices has been created with useful properties as X-ray detectors, radiation monitors and internal beta counters. A wide variety of gas fillings can be used, argon/CH 4 premix being the most convenient. The structures are robust and call for no precision alignments so keeping costs down. Performance of the devices in respect of sensitivity and pulse height resolution is comparable to that of conventional wire counters. (author)

  3. Radiation detectors laboratory; Laboratorio de detectores de radiacion

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez J, F.J. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    1997-07-01

    The Radiation detectors laboratory was established with the assistance of the International Atomic Energy Agency which gave this the responsibility to provide its services at National and regional level for Latin America and it is located at the ININ. The more expensive and delicate radiation detectors are those made of semiconductor, so it has been put emphasis in the use and repairing of these detectors type. The supplied services by this laboratory are: selection consultant, detectors installation and handling and associated systems. Installation training, preventive and corrective maintenance of detectors and detection systems calibration. (Author)

  4. Full LCD detector simulation with GISMO

    International Nuclear Information System (INIS)

    Cassell, Ronald

    2001-01-01

    We present a status update of a full simulation package using GISMO. This package is a functioning tool producing simulation data for the two standard LCD detector designs, in a framework allowing easy changes to the detector designs. The simulation engine, GISMO, is separated from the application code, GISMOAPPS, to allow for a future upgrade to GEANT4 within the same framework

  5. Plasma measurements with surface barrier detectors

    International Nuclear Information System (INIS)

    Futch, A.H. Jr.; Bradley, A.E.

    1969-01-01

    A surface barrier detector system for measuring the loss rate of protons from a hydrogen plasma and their energy spectrum is described. A full width at half maximum (FWHM) resolution of 1.4 keV for 15-keV hydrogen atoms was obtained using a selected detector having a sensitive area of 3 mm 2 and a depletion depth of 700 microns

  6. Comparison of microstructural and mechanical properties of Al–TiC, Al–B4C and Al–TiC–B4C composites prepared by casting techniques

    International Nuclear Information System (INIS)

    Mazaheri, Y.; Meratian, M.; Emadi, R.; Najarian, A.R.

    2013-01-01

    In the present work, production of Al–10%TiC, Al–10% B 4 C, Al–5%TiC–5%B 4 C (volume fraction) composites by casting techniques were studied. However, casting techniques suffers from poor incorporation and distribution of the reinforcement particles in the matrix. These problems become especially significant as the reinforcement size decreases due to greater agglomeration tendency and reduced wettability of the particles with the melt. Microstructure characterization of the composite samples was investigated by using scanning electron microscopy (SEM) equipped with energy dispersive spectroscopy (EDS) and X-ray diffractometer (XRD).The results showed heat treatment of B 4 C particles and addition of TiC particles with the flux improved the wettability and incorporation of reinforcement particles into melt. Mechanical characterization of samples showed that maximum hardness had belonged to Al–5%TiC–5%B 4 C composite, maximum yield and tensile strength had belonged to Al–10%B 4 C composite and maximum elongation had belonged to Al–10%TiC composite. Furthermore, wear properties of composites revealed the better behavior for Al–B 4 C composite.

  7. A novel approach for modeling the cluster detector and the SPI spectrometer

    International Nuclear Information System (INIS)

    Kshetri, Ritesh

    2013-01-01

    Using available experimental data on cluster detector, predictions for the peak-to-total ratio have been given for energy region having no direct experimental information about them. The predictions for the fold distribution are found to be in agreement with the experimental data. The formulation here does not include ad-hoc fits, but expressions that are justifiable by probability flow arguments. Instead of using an empirical method or simulation, a novel approach for calculating the peak-to-total ratio of the cluster detector and the SPI spectrometer for high gamma energies has been presented here. This could provide guidance in designing new composite detectors and in performing experimental studies with the SPI spectrometer for high energy gamma-rays

  8. Detection of 14 MeV neutrons in high temperature environment up to 500 deg. C using 4H-SiC based diode detector

    Energy Technology Data Exchange (ETDEWEB)

    Szalkai, D.; Klix, A. [KIT- Karlsruhe Institute of Technology, Institute of Neutron Physics and Reactor Technology Karlsruhe 76344 (Germany); Ferone, R.; Issa, F.; Ottaviani, L.; Vervisch, V. [IM2NP, UMR CNRS 7334, Aix-Marseille University, Case 231 -13397 Marseille Cedex 20 (France); Gehre, D. [Inst. for Nucl.- and Particle-Phys., Dresden University of Technology, Dresden 01069 (Germany); Lyoussi, A. [CEA, DEN, Departement d' Etudes des Reacteurs, Service de Physique Experimentale, Laboratoire Dosimetrie Capteurs Instrumentation, 13108 Saint-Paul-lez-Durance (France)

    2015-07-01

    In reactor technology and industrial applications detection of fast and thermal neutrons plays a crucial role in getting relevant information about the reactor environment and neutron yield. The inevitable elevated temperatures make neutron yield measurements problematic. Out of the currently available semiconductors 4H-SiC seems to be the most suitable neutron detector material under extreme conditions due to its high heat and radiation resistance, large band-gap and lower cost of production than in case of competing diamond detectors. In the framework of the European I-Smart project, optimal {sup 4}H-SiC diode geometries were developed for high temperature neutron detection and have been tested with 14 MeV fast neutrons supplied by a deuterium-tritium neutron generator with an average neutron flux of 10{sup 10}-10{sup 11} n/(s*cm{sup 2}) at Neutron Laboratory of the Technical University of Dresden in Germany from room temperatures up to several hundred degrees Celsius. Based on the results of the diode measurements, detector geometries appear to play a crucial role for high temperature measurements up to 500 deg. C. Experimental set-ups using SiC detectors were constructed to simulate operation in the harsh environmental conditions found in the tritium breeding blanket of the ITER fusion reactor, which is planned to be the location of neutron flux characterization measurements in the near future. (authors)

  9. Soft x-ray detection with diamond photoconductive detectors

    International Nuclear Information System (INIS)

    Kania, D.R.; Pan, L.; Kornblum, H.; Bell, P.; Landen, O.N.; Pianetta, P.

    1990-01-01

    Photoconductive detectors fabricated from natural lla diamonds have been used to measure the x-ray power emitted from laser produced plasmas. The detector was operated without any absorbing filters to distort the x-ray power measurement. The 5.5 eV bandgap of the detector material practically eliminates its sensitivity to scattered laser radiation thus permitting filterless operation. The detector response time or carrier life time was 90 ps. Excellent agreement was achieved between a diamond PCD and a multichannel photoemissive diode array in the measurement of radiated x-ray power and energy. 4 figs

  10. A large solid angle multiparameter neutron detector

    International Nuclear Information System (INIS)

    Ricco, G.; Anghinolfi, M.; Corvisiero, P.; Durante, E.; Maggiolo, S.; Prati, P.; Rottura, A.; Taiuti, M.

    1991-01-01

    A 4π neutron detector has been realized using organic scintillators: the detector is suitable for high efficiency, low background measurements of very low neutron rates in the 0.6-5 MeV energy range. Gamma-neutron discrimination has been performed by pulse shape, energy and neutron lifetime analysis and backgrounds have been reduced by anticoincidence detectors and paraffin-lead shielding. Tests of efficiency, energy resolution and radiation identification have been made with a low intensity Am-Be neutron source. (orig.)

  11. The Measurement of Spectral Characteristics and Composition of Radiation in Atlas with MEDIPIX2-USB Devices

    Science.gov (United States)

    Campbell, M.; Doležal, Z.; Greiffenberg, D.; Heijne, E.; Holy, T.; Idárraga, J.; Jakůbek, J.; Král, V.; Králík, M.; Lebel, C.; Leroy, C.; Llopart, X.; Lord, G.; Maneuski, D.; Ouellette, O.; Sochor, V.; Pospíšil, S.; Suk, M.; Tlustos, L.; Vykydal, Z.; Wilhelm, I.

    2008-06-01

    A network of devices to perform real-time measurements of the spectral characteristics and composition of radiation in the ATLAS detector and cavern during its operation is being built. This system of detectors will be a stand alone system fully capable of delivering real-time images of fluxes and spectral composition of different particle species including slow and fast neutrons. The devices are based on MEDIPIX2 pixel silicon detectors that will be operated via active USB cables and USB-Ethernet extenders through an Ethernet network by a PC located in the USA15 ATLAS control room. The installation of 14 devices inside ATLAS (detector and cavern) is in progress.

  12. The Measurement of Spectral Characteristics and Composition of Radiation in ATLAS with MEDIPIX2-USB Devices

    CERN Document Server

    Campbell, M.; Greiffenberg, D.; Heijne, E.; Holy, T.; Idárraga, J.; Jakubek, J.; Král, V.; Králík, M.; Lebel, C.; Leroy, C.; Llopart, X.; Lord, G.; Maneuski, D.; Ouellette, O.; Sochor, V.; Prospísil, S.; Suk, M; Tlustos, L.; Vykydal, Z.; Wilhelm, I.

    2008-01-01

    A network of devices to perform real-time measurements of the spectral characteristics and composition of radiation in the ATLAS detector and cavern during its operation is being built. This system of detectors will be a stand alone system fully capable of delivering real-time images of fluxes and spectral composition of different particle species including slow and fast neutrons. The devices are based on MEDIPIX2 pixel silicon detectors that will be operated via active USB cables and USB-Ethernet extenders through an Ethernet network by a PC located in the USA15 ATLAS control room. The installation of 14 devices inside ATLAS (detector and cavern) is in progress.

  13. Rational construction of Z-scheme Ag_2CrO_4/g-C_3N_4 composites with enhanced visible-light photocatalytic activity

    International Nuclear Information System (INIS)

    Luo, Jin; Zhou, Xiaosong; Ma, Lin; Xu, Xuyao

    2016-01-01

    Highlights: • Novel visible-light driven Ag_2CrO_4/g-C_3N_4 composites were synthesized. • Ag_2CrO_4/g-C_3N_4 exhibited enhanced visible-light photocatalytic activity. • The reasons for the enhanced photocatalytic activity were revealed. - Abstract: Novel visible-light driven Z-scheme Ag_2CrO_4/g-C_3N_4 composites with different contents of Ag_2CrO_4 were fabricated by a facile chemical precipitation method and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), UV–vis diffuse reflectance spectroscopy (UV-vis DRS), photoluminescence (PL) spectroscopy and photoelectrochemical measurements. Compared with individual g-C_3N_4 and Ag_2CrO_4, the Ag_2CrO_4/g-C_3N_4 composites displayed much larger photocatalytic activities for the photocatalytic degradation of methyl orange (MO) solution at room temperature under visible light irradiation (λ > 420 nm). Importantly, the optimum photodegradation rate constant of the Ag_2CrO_4/g-C_3N_4 composite at a theoretical weight content of 8.0% Ag_2CrO_4 for the photodegradation of MO was 0.0068 min"−"1, which was 5.7 and 4.3 times higher than that of pure g-C_3N_4 and Ag_2CrO_4, respectively. Such enormous enhancement in photocatalytic performance was predominantly ascribed to the efficient separation and transfer of photogenerated electrons and holes at the Ag_2CrO_4/g-C_3N_4 interface imparted through the Z-scheme electron transfer. Furthermore, radical trap experiments depicted that both the holes and superoxide radical anions were thought to dominate oxidative species of the Ag_2CrO_4/g-C_3N_4 composite for MO degradation under visible light irradiation. Ultimately, a tentative Z-scheme photodegradation mechanism was proposed. This work may be useful for the rational design of new types of Z-scheme photocatalysts and provide some illuminate insights into the Z-scheme transfer mechanism for application in energy

  14. Detector and System Developments for LHC Detector Upgrades

    CERN Document Server

    Mandelli, Beatrice; Guida, Roberto; Rohne, Ole; Stapnes, Steinar

    2015-05-12

    The future Large Hadron Collider (LHC) Physics program and the consequent improvement of the LHC accelerator performance set important challenges to all detector systems. This PhD thesis delineates the studies and strategies adopted to improve two different types of detectors: the replacement of precision trackers with ever increasingly performing silicon detectors, and the improvement of large gaseous detector systems by optimizing their gas mixtures and operation modes. Within the LHC tracker upgrade programs, the ATLAS Insertable B-layer (IBL) is the first major upgrade of a silicon-pixel detector. Indeed the overall ATLAS Pixel Detector performance is expected to degrade with the increase of luminosity and the IBL will recover the performance by adding a fourth innermost layer. The IBL Detector makes use of new pixel and front-end electronics technologies as well as a novel thermal management approach and light support and service structures. These innovations required complex developments and Quality Ass...

  15. Calibration and GEANT4 Simulations of the Phase II Proton Compute Tomography (pCT) Range Stack Detector

    Energy Technology Data Exchange (ETDEWEB)

    Uzunyan, S. A. [Northern Illinois Univ., DeKalb, IL (United States); Blazey, G. [Northern Illinois Univ., DeKalb, IL (United States); Boi, S. [Northern Illinois Univ., DeKalb, IL (United States); Coutrakon, G. [Northern Illinois Univ., DeKalb, IL (United States); Dyshkant, A. [Northern Illinois Univ., DeKalb, IL (United States); Francis, K. [Northern Illinois Univ., DeKalb, IL (United States); Hedin, D. [Northern Illinois Univ., DeKalb, IL (United States); Johnson, E. [Northern Illinois Univ., DeKalb, IL (United States); Kalnins, J. [Northern Illinois Univ., DeKalb, IL (United States); Zutshi, V. [Northern Illinois Univ., DeKalb, IL (United States); Ford, R. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Rauch, J. E. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Rubinov, P. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Sellberg, G. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Wilson, P. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Naimuddin, M. [Univ. of Delhi, New Delhi (India)

    2015-12-29

    Northern Illinois University in collaboration with Fermi National Accelerator Laboratory (FNAL) and Delhi University has been designing and building a proton CT scanner for applications in proton treatment planning. The Phase II proton CT scanner consists of eight planes of tracking detectors with two X and two Y coordinate measurements both before and after the patient. In addition, a range stack detector consisting of a stack of thin scintillator tiles, arranged in twelve eight-tile frames, is used to determine the water equivalent path length (WEPL) of each track through the patient. The X-Y coordinates and WEPL are required input for image reconstruction software to find the relative (proton) stopping powers (RSP) value of each voxel in the patient and generate a corresponding 3D image. In this Note we describe tests conducted in 2015 at the proton beam at the Central DuPage Hospital in Warrenville, IL, focusing on the range stack calibration procedure and comparisons with the GEANT~4 range stack simulation.

  16. A calibration method for phoswich detectors

    CERN Document Server

    Gawlikowicz, W; Schröder, W U

    2002-01-01

    A new method of particle identification and energy calibration is proposed for phoswich detectors consisting of a fast plastic scintillator optically coupled to a CsI(Tl) crystal. In this method, functional relationships between integrated yields of three properly selected portions of the observed composite light output signal are parameterized in terms of three physical components (overlapping in time) of this signal. Then, a complete set of calibration constants is derived, linking these integrated partial yields to particle atomic numbers (Z) and energies (E). The calibration is based on the correlations between partial yields observed in actual data from the physics or 'production' runs, and energy deposits calculated for detector elements. The method is found suitable for a wide range of incident particle species and energies, largely eliminating the need for costly and time-consuming conventional calibration experiments with a variety of beams, targets, and bombarding energies.

  17. Optical sensor platform based on cellulose nanocrystals (CNC) - 4'-(hexyloxy)-4-biphenylcarbonitrile (HOBC) bi-phase nematic liquid crystal composite films.

    Science.gov (United States)

    Santos, Moliria V; Tercjak, Agnieszka; Gutierrez, Junkal; Barud, Hernane S; Napoli, Mariana; Nalin, Marcelo; Ribeiro, Sidney J L

    2017-07-15

    The preparation of composite materials has gained tremendous attention due to the potential synergy of the combined materials. Here we fabricate novel thermal/electrical responsive photonic composite films combining cellulose nanocrystals (CNC) with a low molecular weight nematic liquid crystal (NLC), 4'-(hexyloxy)-4-biphenylcarbonitrile (HOBC). The obtained composite material combines both intense structural coloration of photonic cellulose and thermal and conductive properties of NLC. Scanning electron microscopy (SEM) results confirmed that liquid crystals coated CNC films maintain chiral nematic structure characteristic of CNC film and simultaneously, transversal cross-section scanning electron microscopy images indicated penetration of liquid crystals through the CNC layers. Investigated composite film maintain NLC optical properties being switchable as a function of temperature during heating/cooling cycles. The relationship between the morphology and thermoresponsive in the micro/nanostructured materials was investigated by using transmission optical microscopy (TOM). Conductive response of the composite films was proved by Electrostatic force microscopy (EFM) measurement. Designed thermo- and electro-responsive materials open novel simple pathway of fabrication of CNC-based materials with tunable properties. Copyright © 2017. Published by Elsevier Ltd.

  18. Tracking Detectors in the STAR Experiment at RHIC

    Science.gov (United States)

    Wieman, Howard

    2015-04-01

    The STAR experiment at RHIC is designed to measure and identify the thousands of particles produced in 200 Gev/nucleon Au on Au collisions. This talk will focus on the design and construction of two of the main tracking detectors in the experiment, the TPC and the Heavy Flavor Tracker (HFT) pixel detector. The TPC is a solenoidal gas filled detector 4 meters in diameter and 4.2 meters long. It provides precise, continuous tracking and rate of energy loss in the gas (dE/dx) for particles at + - 1 units of pseudo rapidity. The tracking in a half Tesla magnetic field measures momentum and dE/dX provides particle ID. To detect short lived particles tracking close to the point of interaction is required. The HFT pixel detector is a two-layered, high resolution vertex detector located at a few centimeters radius from the collision point. It determines origins of the tracks to a few tens of microns for the purpose of extracting displaced vertices, allowing the identification of D mesons and other short-lived particles. The HFT pixel detector uses detector chips developed by the IPHC group at Strasbourg that are based on standard IC Complementary Metal-Oxide-Semiconductor (CMOS) technology. This is the first time that CMOS pixel chips have been incorporated in a collider application.

  19. One-step synthesis of graphitic-C 3 N 4 /ZnS composites for enhanced supercapacitor performance

    KAUST Repository

    Wei, Binbin

    2017-11-24

    A series of graphitic-C3N4/ZnS (g-C3N4/ZnS) supercapacitor electrode materials have been prepared via a one-step calcination process of zinc acetate/thiourea with different mass ratios under nitrogen atmosphere. The optimized g-C3N4/ZnS composite shows a highest specific capacitance of 497.7 F/g at 1 A/g and good cycling stability with capacitance retention of 80.4% at 5 A/g after 1000 cycles. Moreover, g-C3N4/ZnS composites display an improved supercapacitor performance in terms of specific capacitance compared to the pure g-C3N4 and ZnS. In addition, our designed symmetric supercapacitor device based on g-C3N4/ZnS composite electrodes can exhibit an energy density of 10.4 Wh/kg at a power density of 187.3 W/kg. As a result, g-C3N4/ZnS composites are expected to be a prospective material for supercapacitors and other energy storage applications.

  20. One-step synthesis of graphitic-C 3 N 4 /ZnS composites for enhanced supercapacitor performance

    KAUST Repository

    Wei, Binbin; Liang, Hanfeng; Wang, Rongrong; Zhang, Dongfang; Qi, Zhengbing; Wang, Zhoucheng

    2017-01-01

    A series of graphitic-C3N4/ZnS (g-C3N4/ZnS) supercapacitor electrode materials have been prepared via a one-step calcination process of zinc acetate/thiourea with different mass ratios under nitrogen atmosphere. The optimized g-C3N4/ZnS composite shows a highest specific capacitance of 497.7 F/g at 1 A/g and good cycling stability with capacitance retention of 80.4% at 5 A/g after 1000 cycles. Moreover, g-C3N4/ZnS composites display an improved supercapacitor performance in terms of specific capacitance compared to the pure g-C3N4 and ZnS. In addition, our designed symmetric supercapacitor device based on g-C3N4/ZnS composite electrodes can exhibit an energy density of 10.4 Wh/kg at a power density of 187.3 W/kg. As a result, g-C3N4/ZnS composites are expected to be a prospective material for supercapacitors and other energy storage applications.

  1. Detector Unit

    CERN Multimedia

    1960-01-01

    Original detector unit of the Instituut voor Kernfysisch Onderzoek (IKO) BOL project. This detector unit shows that silicon detectors for nuclear physics particle detection were already developed and in use in the 1960's in Amsterdam. Also the idea of putting 'strips' onto the silicon for high spatial resolution of a particle's impact on the detector were implemented in the BOL project which used 64 of these detector units. The IKO BOL project with its silicon particle detectors was designed, built and operated from 1965 to roughly 1977. Detector Unit of the BOL project: These detectors, notably the ‘checkerboard detector’, were developed during the years 1964-1968 in Amsterdam, The Netherlands, by the Natuurkundig Laboratorium of the N.V. Philips Gloeilampen Fabrieken. This was done in close collaboration with the Instituut voor Kernfysisch Onderzoek (IKO) where the read-out electronics for their use in the BOL Project was developed and produced.

  2. Al-Si/B{sub 4}C composite coatings on Al-Si substrate by plasma spray technique

    Energy Technology Data Exchange (ETDEWEB)

    Sarikaya, Ozkan [Sakarya University, Faculty of Engineering, Department of Mechanical Engineering, Esentepe Campus, Sakarya 54187 (Turkey); Anik, Selahaddin [Sakarya University, Faculty of Engineering, Department of Mechanical Engineering, Esentepe Campus, Sakarya 54187 (Turkey); Aslanlar, Salim [Sakarya University, Faculty of Technical Education, Department of Mechanical Engineering, Esentepe Campus, Sakarya 54187 (Turkey); Cem Okumus, S. [Sakarya University, Faculty of Engineering, Department of Metallurgical and Materials Engineering, Esentepe Campus, Sakarya 54187 (Turkey); Celik, Erdal [Dokuz Eylul University, Engineering Faculty, Department of Metallurgical and Materials Engineering, Buca, Izmir 35160 (Turkey)]. E-mail: erdal.celik@deu.edu.tr

    2007-07-01

    Plasma-sprayed coatings of Al-Si/B{sub 4}C have been prepared on Al-Si piston alloys for diesel engine motors. The Al-Si/B{sub 4}C composite powders including 5-25 wt% B{sub 4}C were prepared by mixing and ball-milling processes. These powders were deposited on Al-Si substrate using an atmospheric plasma spray technique. The coatings have been characterised with respect to phase composition, microstructure, microhardness, bond strength and thermal expansion. It was found that Al, Si, B{sub 4}C and Al{sub 2}O{sub 3} phases were determined in the coatings with approximately 600 {mu}m thick by using X-ray diffraction analysis. Scanning electron microscope observation revealed that boron carbide particles were uniformly distributed in composite coatings and B{sub 4}C particles were fully wetted by Al-Si alloy. Also, no reaction products were observed in Al-Si/B{sub 4}C composite coatings. It was found that surface roughness, porosity, bond strength and thermal expansion coefficient of composite coatings decreased with increasing fraction of the boron carbide particle. It was demonstrated that the higher the B{sub 4}C content, the higher the hardness of coatings because the hardness of B{sub 4}C is higher than that of Al-Si.

  3. Quantitative material decomposition using spectral computed tomography with an energy-resolved photon-counting detector

    International Nuclear Information System (INIS)

    Lee, Seungwan; Choi, Yu-Na; Kim, Hee-Joung

    2014-01-01

    Dual-energy computed tomography (CT) techniques have been used to decompose materials and characterize tissues according to their physical and chemical compositions. However, these techniques are hampered by the limitations of conventional x-ray detectors operated in charge integrating mode. Energy-resolved photon-counting detectors provide spectral information from polychromatic x-rays using multiple energy thresholds. These detectors allow simultaneous acquisition of data in different energy ranges without spectral overlap, resulting in more efficient material decomposition and quantification for dual-energy CT. In this study, a pre-reconstruction dual-energy CT technique based on volume conservation was proposed for three-material decomposition. The technique was combined with iterative reconstruction algorithms by using a ray-driven projector in order to improve the quality of decomposition images and reduce radiation dose. A spectral CT system equipped with a CZT-based photon-counting detector was used to implement the proposed dual-energy CT technique. We obtained dual-energy images of calibration and three-material phantoms consisting of low atomic number materials from the optimal energy bins determined by Monte Carlo simulations. The material decomposition process was accomplished by both the proposed and post-reconstruction dual-energy CT techniques. Linear regression and normalized root-mean-square error (NRMSE) analyses were performed to evaluate the quantitative accuracy of decomposition images. The calibration accuracy of the proposed dual-energy CT technique was higher than that of the post-reconstruction dual-energy CT technique, with fitted slopes of 0.97–1.01 and NRMSEs of 0.20–4.50% for all basis materials. In the three-material phantom study, the proposed dual-energy CT technique decreased the NRMSEs of measured volume fractions by factors of 0.17–0.28 compared to the post-reconstruction dual-energy CT technique. It was concluded that the

  4. Pressureless sintering of dense Si3N4 and Si3N4/SiC composites with nitrate additives

    International Nuclear Information System (INIS)

    Kim, J.Y.; Iseki, Takayoshi; Yano, Toyohiko

    1996-01-01

    The effect of aluminum and yttrium nitrate additives on the densification of monolithic Si 3 N 4 and a Si 3 N 4 /SiC composite by pressureless sintering was compared with that of oxide additives. The surfaces of Si 3 N 4 particles milled with aluminum and yttrium nitrates, which were added as methanol solutions, were coated with a different layer containing Al and Y from that of Si 3 N 4 particles milled with oxide additives. Monolithic Si 3 N 4 could be sintered to 94% of theoretical density (TD) at 1,500 C with nitrate additives. The sintering temperature was about 100 C lower than the case with oxide additives. After pressureless sintering at 1,750 C for 2 h in N 2 , the bulk density of a Si 3 N 4 /20 wt% SiC composite reached 95% TD with nitrate additives

  5. Vickers microhardness comparison of 4 composite resins with different types of filler.

    Directory of Open Access Journals (Sweden)

    René García-Contreras

    2015-10-01

    Full Text Available Composite resins are the material of choice to restore minimal invasive cavities; conversely, it is important to explore the mechanical properties of commercially available dental materials. Objective: To compare the Vickers microhardness (VHN of four available commercial composite resins using standardized samples and methods. Methodology: Composite cylinders were manufactured in a Teflon mould. We used the follow composite resins (n=4/gp: Microhybrid resins [Feeling Lux (Viarden and Amelogen Plus (Ultradent], Hybrid resin [Te-Econom Plus (Ivoclar] and Nanohybrid resin [Filtek Z350 (3M ESPE]. All samples were incubated in distilled water at 37ºC for five days. The test was carried out with microhardness indenter at 10 N, and a dwelling time of 10 s for 9 indentations across the specimens resulting in a total of 36 indentations for each group. Data were subjected to Kolmogorov-Smirnov normality test and ANOVA (post-hoc Tukey test. Results: The VHN mean values ranged from harder to softer as follows: Filtek Z350 (71.96±6.44 (p Amelogen Plus (59.90±4.40 (p Feeling lux (53.52±5.72> Te-Econom Plus (53.26±5.19. Conclusion: According to our results, the microhardness of the evaluated conventional composite resins can withstand the masticatory forces; however nanohybrid composite resins showed better Vickers microhardness and therefore are a more clinically suitable option for minimal invasion treatments.

  6. X-ray photoemission analysis of chemically modified TlBr surfaces for improved radiation detectors

    International Nuclear Information System (INIS)

    Nelson, A. J.; Voss, L. F.; Beck, P. R.; Graff, R. T.; Conway, A. M.; Nikolic, R. J.; Payne, S. A.; Lee, J.-S.; Kim, H.; Cirignano, L.; Shah, K.

    2013-01-01

    We subjected device-grade TlBr to various chemical treatments used in room temperature radiation detector fabrication to determine the resulting surface composition and electronic structure. As-polished TlBr was treated separately with HCl, SOCl 2 , Br:MeOH and HF solutions. High-resolution photoemission measurements on the valence band electronic structure and Tl 4f, Br 3d, Cl 2p and S 2p core lines were used to evaluate surface chemistry and shallow heterojunction formation. Surface chemistry and valence band electronic structure were correlated with the goal of optimizing the long-term stability and radiation response

  7. Facile preparation and enhanced microwave absorption properties of flake carbonyl iron/Fe{sub 3}O{sub 4} composite

    Energy Technology Data Exchange (ETDEWEB)

    Min, Dandan, E-mail: mdd4776@126.com; Zhou, Wancheng; Luo, Fa; Zhu, Dongmei

    2017-08-01

    Highlights: • Flake carbonyl iron/Fe{sub 3}O{sub 4} composites were prepared by surface oxidation technique. • Lower permittivity and modest permeability was obtained by the FCI/Fe{sub 3}O{sub 4} composites. • Enhanced absorption efficiency and broader absorption band were obtained. - Abstract: Flake carbonyl iron/Fe{sub 3}O{sub 4} (FCI/Fe{sub 3}O{sub 4}) composites with enhanced microwave absorption properties were prepared by a direct and flexible surface oxidation technique. The phase structures, morphology, magnetic properties, frequency-dependent electromagnetic and microwave absorption properties of the composites were investigated. The measurement results showed that lower permittivity as well as modest permeability was obtained by the FCI/Fe{sub 3}O{sub 4} composites. The calculated microwave absorption properties indicated that enhanced absorption efficiency and broader absorption band were obtained by the FCI/Fe{sub 3}O{sub 4} composite comparing with the FCI composite. The absorption frequency range with reflection loss (RL) below −5 dB of FCI/Fe{sub 3}O{sub 4} composites at reaction time of 90 min at thickness of 1.5 mm is 13.3 GHz from 4.7 to 18 GHz, while the bandwidth of the FCI composite is only 5.9 GHz from 2.6 to 8.5 GHz at the same thickness. Thus, such absorbers could act as effective and wide broadband microwave absorbers in the GHz range.

  8. Fabrication of double-sided thallium bromide strip detectors

    Energy Technology Data Exchange (ETDEWEB)

    Hitomi, Keitaro, E-mail: keitaro.hitomi@qse.tohoku.ac.jp [Department of Quantum Science and Energy Engineering, Graduate School of Engineering, Tohoku University, Sendai 980-8579 (Japan); Nagano, Nobumichi [Department of Quantum Science and Energy Engineering, Graduate School of Engineering, Tohoku University, Sendai 980-8579 (Japan); Onodera, Toshiyuki [Department of Electronics and Intelligent Systems, Tohoku Institute of Technology, Sendai 982-8577 (Japan); Kim, Seong-Yun; Ito, Tatsuya; Ishii, Keizo [Department of Quantum Science and Energy Engineering, Graduate School of Engineering, Tohoku University, Sendai 980-8579 (Japan)

    2016-07-01

    Double-sided strip detectors were fabricated from thallium bromide (TlBr) crystals grown by the traveling-molten zone method using zone-purified materials. The detectors had three 3.4-mm-long strips with 1-mm widths and a surrounding electrode placed orthogonally on opposite surfaces of the crystals at approximately 6.5×6.5 mm{sup 2} in area and 5 mm in thickness. Excellent charge transport properties for both electrons and holes were observed from the TlBr crystals. The mobility-lifetime products for electrons and holes in the detector were measured to be ~3×10{sup −3} cm{sup 2}/V and ~1×10{sup −3} cm{sup 2}/V, respectively. The {sup 137}Cs spectra corresponding to the gamma-ray interaction position were obtained from the detector. An energy resolution of 3.4% of full width at half maximum for 662-keV gamma rays was obtained from one “pixel” (an intersection of the strips) of the detector at room temperature.

  9. Results from the crystal ball detector at SPEAR

    International Nuclear Information System (INIS)

    Bloom, E.D.

    1979-11-01

    The Crystal Ball detector is a device particularly suited to the measurement of photons with energies lower than 1 GeV. The detector has as its principal component a 16 radiation length thick, highly segmented shell of NaI(Tl) surrounding cylindrical, proportional, and magnetostrictive spark chambers. The main Ball and various elements of the central chambers cover 94% of 4π sr. Segmented endcap NaI(Tl) detectors of 20 radiation lengths behind magneto strictive spark chambers supplement the main Ball. The Ball and endcaps close the solid angle for charged particle and photon detection to 98% of 4π sr. In addition, detectors of interspersed iron and proportional tubes provide for μ-π separation over 15% of 4π sr, about theta/sub CM/ = 90 0 . In this report preliminary results are presented from the data obtained. In particular, QED at E/sub CM/ = 6.5 GeV, R/sub hadron/ and related inclusive distributions, eta branching fractions at J/psi and psi'', and a detailed study of the psionium system are discussed

  10. CdWO{sub 4}-on-MEH-PPV:PS as a candidate for real-time dosimeters

    Energy Technology Data Exchange (ETDEWEB)

    Silva, M.M. [Laboratory of Polymers and Electronic Properties of Materials, UFOP, 35400-000 (Brazil); Novais, S.M.V.; Silva, E.S.S. [Group of Advanced Ceramic Materials, UFS, 49100-000 (Brazil); Schimitberger, T. [Laboratory of Polymers and Electronic Properties of Materials, UFOP, 35400-000 (Brazil); Macedo, Z.S. [Group of Advanced Ceramic Materials, UFS, 49100-000 (Brazil); Bianchi, R.F., E-mail: bianchi@iceb.ufop.br [Laboratory of Polymers and Electronic Properties of Materials, UFOP, 35400-000 (Brazil)

    2012-10-15

    We report on the investigations about the modification of optical properties induced by X-rays onto film detectors of cadmium tungstate (CdWO{sub 4}), poly[2-methoxy-5(2 Prime -ethylhexyloxy)-p-phenylenevinylene] (MEH-PPV) and polystyrene (PS) This device takes advantage of reduction of spectral overlap between the radioluminescence (RL) of CdWO{sub 4} and the absorption of MEH-PPV as it is exposed to radiation, forming the basis of a new dosimeter that is capable of converting the orange-red radioluminescence of PS:MEH-PPV:CdWO{sub 4} into green. We propose an explanation of the optical processes occurring in MEH-PPV:CdWO{sub 4} in terms of the radiation hardness of CdWO{sub 4} combined to the RL-induced degradation of MEH-PPV. Highlights: Black-Right-Pointing-Pointer Thin composite film dosimeters using a combination of a scintillator crystal and a light-emitting polymer. Black-Right-Pointing-Pointer A X-ray dose detector based on MEH-PPV/CdWO{sub 4} materials which are rarely seen together. Black-Right-Pointing-Pointer A new smart, disposable and easy-to-read organic-inorganic radiation detector.

  11. RID-41 gamma flaw detector

    International Nuclear Information System (INIS)

    Glebov, V.N.; Zubkov, V.S.; Majorov, A.N.; Murashev, A.I.; Firstov, V.G.; Yampol'skij, V.V.; Goncharov, V.I.; Sakhanov, A.S.

    1978-01-01

    The design is described and the main characteristics are given of a universal stationary hose-type gamma flow detector with a 60 Co source from 3O to 4g0 Ci for high-productive control of thick-walled products from steel and other materials. The principal units of the instrument are a radiation head, a control panel, and a charge-exchange container. The flaw detector may be used both in shield chambers and in shop or mounting conditions on complying with due requirements of radiation protection. The high activity of the source at relatively small dimensions of its active part ensures good detection of defects. The high radioscopy rate permits to use the flaw detector in conditions of increased background radiation, e.g. during routine repairs and inspections at nuclear power plants. The instrument may also be used in radiometric complexes, and produces a considerable economic effect. This flaw-detector corresponds to ISO and IAEA requirements and may be delivered for export

  12. Hydrothermal synthesis of magnetic Fe{sub 3}O{sub 4}/graphene composites with good electromagnetic microwave absorbing performances

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Lingyu; Zeng, Xiaojun; Li, Xiaopan; Yang, B., E-mail: byang@buaa.edu.cn; Yu, Ronghai, E-mail: rhyu@buaa.edu.cn

    2017-03-15

    The Fe{sub 3}O{sub 4} sub-microspheres have been embedded uniformly into the reduced graphene oxide (rGO) to form a new-type Fe{sub 3}O{sub 4}/rGO composites through a one-pot solvothermal method. The dielectric properties for these magnetic Fe{sub 3}O{sub 4}/rGO composites can be greatly tuned by their different rGO additions. A good impedance matching from the balanced dielectric and magnetic loss is achieved in the Fe{sub 3}O{sub 4}/rGO composites with 4 wt% rGO addition, which dominates their excellent microwave absorbing performances including the minimum reflection loss (RL) value of −45 dB at a frequency of 8.96 GHz with a sample thickness of 3.5 mm and an effective absorption bandwidth of 3.2 GHz (below −10 dB) superior to those of the most magnetic materials and carbon-based composites. The controlled Fe{sub 3}O{sub 4}/rGO composite structure also exhibits high chemical stability and low density, which shows great potential application in high-performance electromagnetic microwave-absorbing materials. - Highlights: • Magnetic Fe{sub 3}O{sub 4}/rGO composites are fabricated by a facile solvothermal method. • The dielectric properties for the Fe{sub 3}O{sub 4}/rGO composites can be tuned. • The Fe{sub 3}O{sub 4}/rGO composites exhibits high chemical stability and low density. • Excellent microwave absorption performances for the composites are obtained.

  13. Status of fully integrated GaAs particle detectors

    International Nuclear Information System (INIS)

    Braunschweig, W.; Breibach, J.; Kubicki, Th.; Luebelsmeyer, K.; Maesing, Th.; Rente, C.; Roeper, Ch.; Siemes, A.

    1999-01-01

    GaAs strip detectors are of interest because of their radiation hardness at room temperature and the high absorption coefficient of GaAs for x-rays. The detectors currently under development will be used in the VLQ-experiment at the H1 experiment at the HERA collider. This will be the first high energy physics experiment where GaAs detectors will be used. The detectors have a sensitive area of 5 x 4 cm with a pitch of 62 μ m. Due to the high density of channels the biasing resistors and coupling capacitors are integrated. For the resistors a resistive layer made of Cermet is used. The properties of the first fully integrated strip detector are presented

  14. Detector problems at the SSC

    International Nuclear Information System (INIS)

    Wojcicki, S.G.

    1985-02-01

    During the last couple of years there has been considerable concern expressed among the US high energy community as to whether detector limitations would prevent one from being able to fully exploit a luminosity of 10 33 cm -2 sec -1 at a hadron-hadron high energy collider. As a result of these concerns, a considerable amount of work has been done recently in trying to understand the nature of potential difficulties and the required R and D that needs to be performed. A lot of this work has been summarized in the 1984 DPF Summer Study at Snowmass. This paper attempts to review some of these results. This work is limited to the discussion of detector problems associated with the study of high energy hadron-hadron collisions. We shall start with the discussion of the desirable features of the detectors and of the SSC environment in which they will have to work. After a brief discussion of the model 4π detectors, we shall discuss specific detector aspects: lepton identification, tracking, calorimetry and computing and triggering. We shall end with some remarks about possible future course of events. 15 refs., 10 figs

  15. Optimization of the collection charge of a detector type LEM

    International Nuclear Information System (INIS)

    Ben Dhahbi, Anis

    2010-01-01

    Several discoveries were made with gaseous detectors, mainly Multi Wires Proportional Chambers M WPC i nvented by G. Charpak. This kind of detector is the ancestor of many detectors used at CERN today, which were used to examine the ultimate constituents of matter and can also be adapted for medical imaging. This work has been included in research and development of a detection plane of Micro Pattern Gaseous Detectors (MPGD) named Large Electron Multiplier (LEM) for better detection by acting on the dimensions of gap and diameter of holes. In this work simulation programs have been conducted to study the configuration of the electric field in the detector, more precisely in the amplification zone to optimize the detector dimensions. The transport properties of electrons inside the detector have been studied in different mixtures of gases (CF4, P10, Xenon-CF4 ...). A prototype was available in the Neuchatel University S witzerland t o study the gain and the energy resolution by detecting low energy radiation ( 55 Fe source with 5.9 keV of energy).

  16. Recent results on the development of radiation-hard diamond detectors

    CERN Document Server

    Conway, J S; Bauer, C; Berdermann, E; Bergonzo, P; Bogani, F; Borchi, E; Brambilla, A; Bruzzi, Mara; Colledani, C; Dabrowski, W; Da Graca, J; Delpierre, P A; Deneuville, A; Dulinski, W; van Eijk, B; Fallou, A; Fizzotti, F; Foulon, F; Friedl, M; Gan, K K; Gheeraert, E; Grigoriev, E; Hallewell, G D; Hall-Wilton, R; Han, S; Hartjes, F G; Hrubec, Josef; Husson, D; Jamieson, D; Kagan, H; Kania, D R; Kaplon, J; Karl, C; Kass, R; Knöpfle, K T; Krammer, Manfred; Lo Giudice, A; Lü, R; Manfredi, P F; Manfredotti, C; Marshall, R D; Meier, D; Mishina, M; Oh, A; Pan, L S; Palmieri, V G; Pernicka, Manfred; Peitz, A; Pirollo, S; Plano, R; Polesello, P; Prawer, S; Pretzl, Klaus P; Procario, M; Re, V; Riester, J L; Roe, S; Roff, D G; Rudge, A; Russ, J; Schnetzer, S; Sciortino, S; Somalwar, S V; Speziali, V; Stelzer, H; Stone, R; Suter, B; Tapper, R J; Tesarek, R; Thomson, G B; Trawick, M; Trischuk, W; Vittone, E; Walsh, A M; Wedenig, R; Weilhammer, Peter; White, C; Ziock, H J; Zöller, M

    1999-01-01

    Charged particle detectors made from chemical vapor deposition (CVD) diamond have radiation hardness greatly exceeding that of silicon- based detectors. The CERN-based RD42 Collaboration has developed and tested CVD diamond microstrip and pixel detectors with an eye to their application in the intense radiation environment near the interaction region of hadron colliders. This paper presents recent results from tests of these detectors. (4 refs).

  17. The status of the Brazilian spherical detector

    International Nuclear Information System (INIS)

    Aguiar, O D; Andrade, L A; Filho, L Camargo; Costa, C A; Araujo, J C N de; Neto, E C de Rey; Souza, S T de; Fauth, A C; Frajuca, C; Frossati, G; Furtado, S R; Furtado, V G S; Magalhaes, N S; Jr, R M Marinho; Matos, E S; Meliani, M T; Melo, J L; Miranda, O D; Jr, N F Oliveira; Ribeiro, K L; Salles, K B M; Stellati, C; Jr, W F Velloso

    2002-01-01

    The first phase of the Brazilian Graviton Project is the construction and operation of the gravitational wave detector Mario Schenberg at the Physics Institute of the University of Sao Paulo. This gravitational wave spherical antenna is planned to feature a sensitivity better than h = 10 -21 Hz -1/2 at the 3.0-3.4 kHz bandwidth, and to work not only as a detector, but also as a testbed for the development of new technologies. Here we present the status of this detector

  18. Amorphous selenium based detectors for medical imaging applications

    Science.gov (United States)

    Mandal, Krishna C.; Kang, Sung H.; Choi, Michael; Jellison, Gerald E., Jr.

    2006-08-01

    We have developed and characterized large volume amorphous (a-) selenium (Se) stabilized alloys for room temperature medical imaging devices and high-energy physics detectors. The synthesis and preparation of well-defined and high quality a-Se (B, As, Cl) alloy materials have been conducted using a specially designed alloying reactor at EIC and installed in an argon atmosphere glove box. The alloy composition has been precisely controlled and optimized to ensure good device performance. The synthesis of large volume boron (B) doped (natural and isotopic 10B) a-Se (As, Cl) alloys has been carried out by thoroughly mixing vacuum distilled and zone-refined (ZR) Se with previously synthesized Se-As master alloys, Se-Cl master alloys and B. The synthesized a-Se (B, As, Cl) alloys have been characterized by x-ray diffraction (XRD), differential scanning calorimetry (DSC), Fourier transform infra-red spectroscopy (FTIR), x-ray photoelectron spectroscopy (XPS), inductively coupled plasma mass spectroscopy (ICP-MS), and detector testing. The a- Se alloys have shown high promise for x-ray detectors with its high dark resistivity (10 10-10 13 Ωcm), good charge transport properties, and cost-effective large area scalability. Details of various steps about detector fabrication and testing of these imaging devices are also presented.

  19. Search for the solar pp-neutrinos with an upgrade of CTF detector

    International Nuclear Information System (INIS)

    Smirnov, O.Yu.; Zajmidoroga, O.A.; Derbin, A.V.

    2001-01-01

    A possibility to use ultrapure liquid organic scintillator as a low energy solar neutrino detector is discussed. The detector with an active volume of 10 tons and 4π coverage will count 1.8 pp-neutrinos and 5.4 7 Be neutrinos per day with an energy threshold of 170 keV for the recoil electrons. The evaluation of the detector sensitivity and backgrounds is based on the results obtained by the Borexino collaboration with the Counting Test Facility (CTF). The detector can be build at the Italian Gran Sasso underground laboratory as an upgrade of the CTF detector using already developed technologies

  20. Measurement of charge composition of electron flows with an energy above hundreds MeV in inner radiaion belt

    International Nuclear Information System (INIS)

    Gusev, A.A.; Pugacheva, G.I.

    1990-01-01

    A detector for studying the charge composition of a high-energy electron component of an internal radiation belt when measuring the precipitation of charged particles in the region of Brazil magnetic anomaly is suggested. The detector is a telescope consisting of two semiconductors and CsI crystal housed into a protection detector in the form of a cup made of plastic scintillator. An absorber of plastic scintillator is placed between semiconductive detections. The detector may record positrons with energy up to 5 MeV in the composition of precipitating particles from the belt in definite detector signal combination and specific energy release 511 keV in CsI crystal. 16 refs.; 3 figs

  1. CdWO4 polymorphs: Selective preparation, electronic structures, and photocatalytic activities

    International Nuclear Information System (INIS)

    Yan, Tingjiang; Li, Liping; Tong, Wenming; Zheng, Jing; Wang, Yunjian; Li, Guangshe

    2011-01-01

    This work explored the selective synthesis of polymorphs of CdWO 4 in either tetragonal or monoclinic phase by optimizing the experimental parameters. Systematic characterization indicated that both polymorphs possessed similar spherical morphologies but different structural building blocks. Electronic structures calculations for both polymorphs demonstrated the same constructions of conduction band or valence band, while the conduction band widths of both polymorphs were quite different. Both CdWO 4 polymorphs exhibited good photocatalytic activity for degradation of methyl orange under UV light irradiation. When comparing to some other well-known tungstate oxide materials, the photocatalytic activity was found to follow such a consequence, monoclinic CdWO 4 ∼monoclinic ZnWO 4 >tetragonal CdWO 4 >tetragonal CaWO 4 . The specific photocatalytic activity of monoclinic CdWO 4 was even higher than that of commercial TiO 2 photocatalyst (Degussa P25). The increased activity from the tetragonal CdWO 4 to the monoclinic was consistent with the trend of the decreased symmetry, and this could be explained in terms of the geometric structures and electronic structures for both polymorphs. -- Graphical abstract: Monoclinic CdWO 4 exhibited a much higher photocatalytic activity than the tetragonal form owing to the lower symmetry, more distorted geometric structure, and the dispersive band configuration. Display Omitted Research highlights: → Polymorphs of CdWO 4 in either tetragonal or monoclinic phase were selectively synthesized. → Both polymorphs possessed similar spherical morphologies, while the relevant structural building blocks were different. → Photocatalytic activities of CdWO 4 polymorphs depended strongly on the symmetry, geometric structure, as well as band configuration.

  2. Performance characterization of the EarthCARE BBR Detectors

    Science.gov (United States)

    Proulx, C.; Allard, M.; Pope, T.; Tremblay, B.; Williamson, F.; Julien, C.; Larouche, C.; Delderfield, J.; Parker, D.

    2017-11-01

    The Broadband Radiometer (BBR) is an instrument being developed for the ESA EarthCARE satellite. The BBR instrument objective is to provide measurements of the reflected short-wave (0.25-4.0 μm) and emitted long-wave (4.0-50 μm) top of the atmosphere (TOA) radiance over three along-track views (forward, nadir and backward). The instrument has three fixed telescopes, one for each view, each containing a broadband detector. The BBR instrument is led by SEA in the UK with RAL responsible for the BBR optics unit (OU) while EADS Astrium is the EarthCARE prime contractor. A detailed description of the instrument is provided in [1]. The BBR detectors consist in three dedicated assemblies under the responsibility of INO. The detectors development started in 2008 and led to the design and implementation of a new gold black deposition facility at INO [2], in parallel with the preliminary and detailed design phases of the detector assemblies. As of today, two breadboard models and one engineering model have been delivered to RAL. In the BBR OU each detector mechanically interfaces with the telescope and electrically with the front-end electronics (FEE). The detectors' development is now at the Critical Design Review (CDR) level. This paper first provides a description of the detector design along with its principles of operation. It further presents and discusses measurement and analysis results for the performance characterization of the engineering model in the context of the applicable requirements. Detector-level qualification planning is finally discussed.

  3. Device simulation and optimization of laterally-contacted-unipolar-nuclear detector

    CERN Document Server

    Lee, E Y

    1999-01-01

    Unipolar gamma-ray detectors offer the possibility of enhanced energy resolution and detection sensitivity over the conventional planar detectors. However, these detectors are difficult to understand and to fabricate, due to their three-dimensional geometry and multiple electrodes. Computer simulation offers a powerful way to design and to optimize these detectors, by giving the internal electric fields, weighting potentials, and spatially resolved detector responses. Simulation and optimization of an unipolar gamma-ray detector called laterally-contacted-unipolar-nuclear detector (LUND) are shown. For 662 keV gamma-rays from a sup 1 sup 3 sup 7 Cs source, the simulation and optimization of LUND resulted in improvement in the energy resolution from 1.6% to 1.3% and improvement in the active detector volume from 4% to 38% of the total detector volume.

  4. Easily Dispersible NiFe2O4/RGO Composite for Microwave Absorption Properties in the X-Band

    Science.gov (United States)

    Bateer, Buhe; Zhang, Jianjao; Zhang, Hongchen; Zhang, Xiaochen; Wang, Chunyan; Qi, Haiqun

    2018-01-01

    Composites with good dispersion and excellent microwave absorption properties have important applications. Therefore, an easily dispersible NiFe2O4/reduced graphene oxide (RGO) composite has been prepared conveniently through a simple hydrothermal method. Highly crystalline, small size (about 7 nm) monodispersed NiFe2O4 nanoparticles (NPs) are evenly distributed on the surface of RGO. The microwave absorbability revealed that the NiFe2O4/RGO composite exhibits excellent microwave absorption properties in the X-band (8-12 GHz), and the minimum reflection loss of the NiFe2O4/RGO composite is -27.7 dB at 9.2 GHz. The NiFe2O4/RGO composite has good dispersibility in nonpolar solvent, which facilitates the preparation of stable commercial microwave absorbing coatings. It can be a promising candidate for lightweight microwave absorption materials in many application fields.

  5. Neutron and X-ray Detectors

    Energy Technology Data Exchange (ETDEWEB)

    Carini, Gabriella [SLAC National Accelerator Lab., Menlo Park, CA (United States); Denes, Peter [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Gruener, Sol [Cornell Univ., Ithaca, NY (United States); Lessner, Elianne [Dept. of Energy (DOE), Washington DC (United States). Office of Science Office of Basic Energy Sciences

    2012-08-01

    The Basic Energy Sciences (BES) X-ray and neutron user facilities attract more than 12,000 researchers each year to perform cutting-edge science at these state-of-the-art sources. While impressive breakthroughs in X-ray and neutron sources give us the powerful illumination needed to peer into the nano- to mesoscale world, a stumbling block continues to be the distinct lag in detector development, which is slowing progress toward data collection and analysis. Urgently needed detector improvements would reveal chemical composition and bonding in 3-D and in real time, allow researchers to watch “movies” of essential life processes as they happen, and make much more efficient use of every X-ray and neutron produced by the source The immense scientific potential that will come from better detectors has triggered worldwide activity in this area. Europe in particular has made impressive strides, outpacing the United States on several fronts. Maintaining a vital U.S. leadership in this key research endeavor will require targeted investments in detector R&D and infrastructure. To clarify the gap between detector development and source advances, and to identify opportunities to maximize the scientific impact of BES user facilities, a workshop on Neutron and X-ray Detectors was held August 1-3, 2012, in Gaithersburg, Maryland. Participants from universities, national laboratories, and commercial organizations from the United States and around the globe participated in plenary sessions, breakout groups, and joint open-discussion summary sessions. Sources have become immensely more powerful and are now brighter (more particles focused onto the sample per second) and more precise (higher spatial, spectral, and temporal resolution). To fully utilize these source advances, detectors must become faster, more efficient, and more discriminating. In supporting the mission of today’s cutting-edge neutron and X-ray sources, the workshop identified six detector research challenges

  6. Determining dose rate with a semiconductor detector - Monte Carlo calculations of the detector response

    Energy Technology Data Exchange (ETDEWEB)

    Nordenfors, C

    1999-02-01

    To determine dose rate in a gamma radiation field, based on measurements with a semiconductor detector, it is necessary to know how the detector effects the field. This work aims to describe this effect with Monte Carlo simulations and calculations, that is to identify the detector response function. This is done for a germanium gamma detector. The detector is normally used in the in-situ measurements that is carried out regularly at the department. After the response function is determined it is used to reconstruct a spectrum from an in-situ measurement, a so called unfolding. This is done to be able to calculate fluence rate and dose rate directly from a measured (and unfolded) spectrum. The Monte Carlo code used in this work is EGS4 developed mainly at Stanford Linear Accelerator Center. It is a widely used code package to simulate particle transport. The results of this work indicates that the method could be used as-is since the accuracy of this method compares to other methods already in use to measure dose rate. Bearing in mind that this method provides the nuclide specific dose it is useful, in radiation protection, since knowing what the relations between different nuclides are and how they change is very important when estimating the risks

  7. Calibration Improvements in the Detector-to-Detector Differences for the MODIS Ocean Color Bands

    Science.gov (United States)

    Li, Yonghong; Angal, Amit; Wu, Aisheng; Geng, Xu; Link, Daniel; Xiong, Xiaoxiong

    2016-01-01

    The Moderate Resolution Imaging Spectroradiometer (MODIS), a major instrument within NASAs Earth Observation System missions, has operated for over 16 and 14 years onboard the Terra and Aqua satellites, respectively. Its reflective solar bands (RSB) covering a spectral range from 0.4 to 2.1 micrometers are primarily calibrated using the on-board solar diffuser(SD), with its on-orbit degradation monitored using the Solar Diffuser Stability Monitor. RSB calibrations are supplemented by near-monthly lunar measurements acquired from the instruments space-view port. Nine bands (bands 8-16) in the visible to near infrared spectral range from 0.412 to 0.866 micrometers are primarily used for ocean color observations.During a recent reprocessing of ocean color products, performed by the NASA Ocean Biology Processing Group, detector-to-detector differences of up to 1.5% were observed in bands 13-16 of Terra MODIS. This paper provides an overview of the current approach to characterize the MODIS detector-to-detector differences. An alternative methodology was developed to mitigate the observed impacts for bands 13-16. The results indicated an improvement in the detector residuals and in turn are expected to improve the MODIS ocean color products. This paper also discusses the limitations,subsequent enhancements, and the improvements planned for future MODIS calibration collections.

  8. WFC3 UVIS Detector Performance

    Science.gov (United States)

    Gunning, Heather C.; Baggett, Sylvia M.; Gosmeyer, Catherine; Bourque, Matthew; MacKenty, John W.; Anderson, Jay; WFC3 Team

    2015-01-01

    The Wide Field Camera 3 (WFC3) is a fourth-generation imaging instrument installed on the Hubble Space Telescope (HST) during Servicing Mission 4 (SM4) in May 2000. WFC3 has two observational channels, UV/visible (UVIS) and infrared (IR); both have been performing well on-orbit. Since installation, the WFC3 team has been diligent in monitoring the performance of both detectors. The UVIS channel consists of two e2v, backside illuminated, 2Kx4K CCDs arranged in a 2x1 mosaic. We present results from some of the monitoring programs used to check various aspects of the UVIS detector. We discuss the growth trend of hot pixels and the efficacy of regular anneals in controlling the hot pixel population. We detail a pixel population with lowered-sensitivity that evolves during the time between anneals, and is largely reset by each anneal procedure. We discuss the stability of the post-flash LED lamp, used and recommended for CTE mitigation in observations with less than 12 e-/pixel backgrounds. Finally, we summarize long-term photometric trends of the UVIS detector, as well as the absolute gain measurement, used as a proxy for the on-orbit evolution of the UVIS channel.

  9. The OPAL muon barrel detector

    International Nuclear Information System (INIS)

    Akers, R.J.; Allison, J.; Ashton, P.; Bahan, G.A.; Baines, J.T.M.; Banks, J.N.; Barlow, R.J.; Barnett, S.; Beeston, C.; Chrin, J.T.M.; Clowes, S.G.; Davies, O.W.; Duerdoth, I.P.; Hinde, P.S.; Hughes-Jones, R.E.; Lafferty, G.D.; Loebinger, F.K.; Macbeth, A.A.; McGowan, R.F.; Moss, M.W.; Murphy, P.G.; Nijjhar, B.; O'Dowd, A.J.P.; Pawley, S.J.; Phillips, P.D.; Richards, G.E.; Skillman, A.; Stephens, K.; Tresillian, N.J.; Wood, N.C.; Wyatt, T.R.

    1995-01-01

    The barrel part of the OPAL muon detector consists of 110 drift chambers forming four layers outside the hadron absorber. Each chamber covers an area of 1.2 m by up to 10.4 m and has two cells with wires parallel to the beam and a drift distance of 297 mm. A detailed description of the design, construction, operation and performance of the sub-detector is given. The system has been operating successfully since the start of LEP in 1989. ((orig.))

  10. Gas-discharge particle detector with ball-tipped anodes

    International Nuclear Information System (INIS)

    Travkin, V.I.; Khazins, D.M.

    1987-01-01

    A new gas-discharge particle detector, whose anode is a set of balls 2mm in diameter is investigated. The chamber is blowing down by the argon-methane-methylal gas mixture with the ratio 3:1:1. The detector operates in the self-quenching streamer mode, has high efficiency and a wide counting characteristic plateau. The maximum counting rate of particles at one ball is ∼ 2.5x10 4 s -1 . The ball-tipped anodes allow making reliable complex-shaped detectors. Two-coordinate detection of multiparticle events can be naturally organized in detectors like that

  11. Large area liquid argon detectors for interrogation systems

    Energy Technology Data Exchange (ETDEWEB)

    Gary, Charles; Kane, Steve; Firestone, Murray I.; Smith, Gregory [Adelphi Technology LLC, Purdue Technology Center, 5225 Exploration Drive, Indianapolis, IN 46241 (United States); Gozani, Tsahi; Brown, Craig; Kwong, John; King, Michael J. [Rapiscan Laboratories, 520 Almanor Avenue, Sunnyvale, CA 94085 (United States); Nikkel, James A.; McKinsey, Dan [Physics Department, Yale University, New Haven, CT 06520 (United States)

    2013-04-19

    Measurements of the efficiency, pulse shape, and energy and time resolution of liquid argon (LAr) detectors are presented. Liquefied noble gas-based (LNbG) detectors have been developed for the detection of dark matter and neutrinoless double-beta decay. However, the same qualities that make LNbG detectors ideal for these applications, namely their size, cost, efficiency, pulse shape discrimination and resolution, make them promising for portal screening and the detection of Special Nuclear Materials (SNM). Two 18-liter prototype detectors were designed, fabricated, and tested, one with pure LAr and the other doped with liquid Xe (LArXe). The LArXe detector presented the better time and energy resolution of 3.3 ns and 20% at 662 KeV, respectively. The total efficiency of the detector was measured to be 35% with 4.5% of the total photons detected in the photopeak.

  12. Large area liquid argon detectors for interrogation systems

    International Nuclear Information System (INIS)

    Gary, Charles; Kane, Steve; Firestone, Murray I.; Smith, Gregory; Gozani, Tsahi; Brown, Craig; Kwong, John; King, Michael J.; Nikkel, James A.; McKinsey, Dan

    2013-01-01

    Measurements of the efficiency, pulse shape, and energy and time resolution of liquid argon (LAr) detectors are presented. Liquefied noble gas-based (LNbG) detectors have been developed for the detection of dark matter and neutrinoless double-beta decay. However, the same qualities that make LNbG detectors ideal for these applications, namely their size, cost, efficiency, pulse shape discrimination and resolution, make them promising for portal screening and the detection of Special Nuclear Materials (SNM). Two 18-liter prototype detectors were designed, fabricated, and tested, one with pure LAr and the other doped with liquid Xe (LArXe). The LArXe detector presented the better time and energy resolution of 3.3 ns and 20% at 662 KeV, respectively. The total efficiency of the detector was measured to be 35% with 4.5% of the total photons detected in the photopeak.

  13. A High-Granularity Timing Detector for the Phase-II upgrade of the ATLAS Detector System

    CERN Document Server

    Agapopoulou, Christina; The ATLAS collaboration

    2017-01-01

    The expected increase of the particle flux at the high luminosity phase of the LHC with instantaneous luminosities up to L = 7.5 × 10^{34} cm^{−2}s^{−1} will have a severe impact on pile-up. The pile-up is expected to increase on average to 200 interactions per bunch crossing. The reconstruction performance for especially jets and transverse missing energy will be severely degraded in the end-cap and forward region of the ATLAS detector. A High Granularity Timing Detector (HGTD) is proposed in front of the liquid Argon end-cap calorimeters of ATLAS for pile-up mitigation in the offline reconstruction. An additional use of the detector as a luminometer is proposed. This device covers the pseudo-rapidity range of 2.4 to about 4. Four layers of Silicon sensors are foreseen to provide precision timing information with a time resolution of the order of 30 picoseconds per minimum ionizing particle in order to assign the energy deposits in the calorimeter to different proton-proton collision vertices. Each read...

  14. Determination of the detection efficiency of a HPGe detector by means of the MCNP 4A simulation code

    International Nuclear Information System (INIS)

    Leal, B.

    2004-01-01

    In the majority of the laboratories, the calibration in efficiency of the detector is carried out by means of the standard sources measurement of gamma photons that have a determined activity, or for matrices that contain a variety of radionuclides that can embrace the energy range of interest. Given the experimental importance that has the determination from the curves of efficiency to the effects of establishing the quantitative results, is appealed to the simulation of the response function of the detector used in the Regional Center of Nuclear Studies inside the energy range of 80 keV to 1400 keV varying the density of the matrix, by means of the application of the Monte Carlo code MCNP-4A. The adjustment obtained shows an acceptance grade in the range of 100 to 600 keV, with a smaller percentage discrepancy to 5%. (Author)

  15. Composite perovskite materials, methods of making, and methods of use

    KAUST Repository

    Yu, Weili; Amassian, Aram

    2017-01-01

    Embodiments of the present disclosure provide materials, devices and systems including a composite of halide perovskite single crystals and nanotubes, and the like. Embodiments of the composite can be used in devices such as detectors, solar panels, transistors, sensors, and the like.

  16. Composite perovskite materials, methods of making, and methods of use

    KAUST Repository

    Yu, Weili

    2017-12-14

    Embodiments of the present disclosure provide materials, devices and systems including a composite of halide perovskite single crystals and nanotubes, and the like. Embodiments of the composite can be used in devices such as detectors, solar panels, transistors, sensors, and the like.

  17. Scintillators

    International Nuclear Information System (INIS)

    Cusano, D.A.; Holub, F.F.; Prochazka, S.

    1979-01-01

    Scintillator bodies comprising phosphor materials and having high optical translucency with low light absorption, and methods of making the scintillator bodies, are described. Fabrication methods include (a) a hot-pressing process, (b) cold-pressing followed by sintering, (c) controlled cooling from a melt, and (d) hot-forging. The scintillator bodies that result are easily machined to desired shapes and sizes. Suitable phosphors include BaFCl:Eu, LaOBr:Tb, CsI:Tl, CaWO 4 and CdWO 4 . (U.K.)

  18. The International Linear Collider Technical Design Report - Volume 4: Detectors

    Energy Technology Data Exchange (ETDEWEB)

    Behnke, Ties [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

    2013-06-26

    The International Linear Collider Technical Design Report (TDR) describes in four volumes the physics case and the design of a 500 GeV centre-of-mass energy linear electron-positron collider based on superconducting radio-frequency technology using Niobium cavities as the accelerating structures. The accelerator can be extended to 1 TeV and also run as a Higgs factory at around 250 GeV and on the Z0 pole. A comprehensive value estimate of the accelerator is give, together with associated uncertainties. It is shown that no significant technical issues remain to be solved. Once a site is selected and the necessary site-dependent engineering is carried out, construction can begin immediately. The TDR also gives baseline documentation for two high-performance detectors that can share the ILC luminosity by being moved into and out of the beam line in a "push-pull" configuration. These detectors, ILD and SiD, are described in detail. They form the basis for a world-class experimental programme that promises to increase significantly our understanding of the fundamental processes that govern the evolution of the Universe.

  19. Shower maximum detector for SDC calorimetry

    International Nuclear Information System (INIS)

    Ernwein, J.

    1994-01-01

    A prototype for the SDC end-cap (EM) calorimeter complete with a pre-shower and a shower maximum detector was tested in beams of electrons and Π's at CERN by an SDC subsystem group. The prototype was manufactured from scintillator tiles and strips read out with 1 mm diameter wave-length shifting fibers. The design and construction of the shower maximum detector is described, and results of laboratory tests on light yield and performance of the scintillator-fiber system are given. Preliminary results on energy and position measurements with the shower max detector in the test beam are shown. (authors). 4 refs., 5 figs

  20. Simulation framework and XML detector description for the CMS experiment

    CERN Document Server

    Arce, P; Boccali, T; Case, M; de Roeck, A; Lara, V; Liendl, M; Nikitenko, A N; Schröder, M; Strässner, A; Wellisch, H P; Wenzel, H

    2003-01-01

    Currently CMS event simulation is based on GEANT3 while the detector description is built from different sources for simulation and reconstruction. A new simulation framework based on GEANT4 is under development. A full description of the detector is available, and the tuning of the GEANT4 performance and the checking of the ability of the physics processes to describe the detector response is ongoing. Its integration on the CMS mass production system and GRID is also currently under development. The Detector Description Database project aims at providing a common source of information for Simulation, Reconstruction, Analysis, and Visualisation, while allowing for different representations as well as specific information for each application. A functional prototype, based on XML, is already released. Also examples of the integration of DDD in the GEANT4 simulation and in the reconstruction applications are provided.

  1. New electronics for the surface detectors of the Pierre Auger Observatory

    Energy Technology Data Exchange (ETDEWEB)

    Kleifges, M., E-mail: Matthias.Kleifges@kit.edu [Karlsruhe Institute of Technology – Institute for Data Processing and Electronics, Karlsruhe (Germany)

    2016-07-11

    The Pierre Auger Observatory is the largest installation worldwide for the investigation of ultra-high energy cosmic rays. Air showers are detected using a hybrid technique with 27 fluorescence telescopes and 1660 water-Cherenkov detectors (WCD) distributed over about 3000 km{sup 2}. The Auger Collaboration has decided to upgrade the electronics of the WCD and complement the surface detector with scintillators (SSD). The objective is to improve the separation between the muonic and the electron/photon shower component for better mass composition determination during an extended operation period of 8–10 years. The surface detector electronics records data locally and generates time stamps based on the GPS timing. The performance of the detectors is significantly improved with a higher sampling rate, an increased dynamic range, new generation of GPS receivers, and FPGA integrated CPU power. The number of analog channels will be increased to integrate the new SSD, but the power consumption needs to stay below 10 W to be able to use the existing photovoltaic system. In this paper, the concept of the additional SSD is presented with a focus on the design and performance of the new surface detector electronics.

  2. Density and water content measurement with two dual detector probes

    International Nuclear Information System (INIS)

    Cariou, J.; Menard, J.

    1980-01-01

    The ''Laboratoires des Ponts et Chaussees'' have developed an electronic device for geological prospections. This system includes gamma-gamma and neutron-neutron probes for continuous measurement in borehole down to one hundred meters. It is used, as well to measure the density and the water content in the field of soil mechanic engineering. When the diameter is not constant all along the borehole the two probes have to use a dual detector procedure. When constant, a simple detector procedure is sufficient to obtain density and water content. Two examples show the possibilities of this apparatus, particularly to control the borehole diameter and the soil chemical composition [fr

  3. 46 CFR 108.407 - Detectors for electric fire detection system.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Detectors for electric fire detection system. 108.407... DRILLING UNITS DESIGN AND EQUIPMENT Fire Extinguishing Systems § 108.407 Detectors for electric fire detection system. (a) Each detector in an electric fire detection system must be located where— (1) No...

  4. Two-dimensional position sensitive neutron detector

    Indian Academy of Sciences (India)

    The detector is a 3He + Kr filled multiwire proportional counter with charge division position readout and has a sensitive area of 345 mm × 345 mm, pixel size 5 mm × 5 mm, active depth 25 mm and is designed for efficiency of 70% for 4 Å neutrons. The detector is tested with 0.5 bar 3He + 1.5 bar krypton gas mixture in active ...

  5. UV-light-assisted ethanol sensing characteristics of g-C3N4/ZnO composites at room temperature

    Science.gov (United States)

    Zhai, Jiali; Wang, Tao; Wang, Chuang; Liu, Dechen

    2018-05-01

    A highly efficient UV-light-assisted room temperature sensor based on g-C3N4/ZnO composites were prepared by an in situ precipitation method. The thermostability, composition, structure, and morphology properties of the as-prepared g-C3N4/ZnO composites were characterized by TGA, XRD, FT-IR, TEM, and XPS, respectively. And then, we studied the ethanol (C2H5OH) sensing performance of the g-C3N4/ZnO composites at the room temperature. Compared with pure ZnO and g-C3N4, the gas sensing activity of g-C3N4/ZnO composites was greatly improved at room temperature, for example, the g-C3N4/ZnO-8% composites showed an obvious response of 121-40 ppm C2H5OH at room temperature, which was 60 times higher than the pure ZnO based on the sensors under the same condition. The great enhancement of the C2H5OH sensing properties of composites can be understood by the efficient separation of photogenerated charge carriers of g-C3N4/ZnO heterogeneous and the UV-light catalytic effect. Finally, a possible mechanism for the gas sensing activity was proposed.

  6. Silicon detectors

    International Nuclear Information System (INIS)

    Klanner, R.

    1984-08-01

    The status and recent progress of silicon detectors for high energy physics is reviewed. Emphasis is put on detectors with high spatial resolution and the use of silicon detectors in calorimeters. (orig.)

  7. A study of composite models at LEP with ALEPH

    International Nuclear Information System (INIS)

    Badaud, F.

    1992-04-01

    Tests of composite models are performed in e + e - collisions in the vicinity of the Z 0 pole using the ALEPH detector. Two kinds of substructure effects are searched for: deviations of differential cross section for reactions e + e - → l + l - and e + e - → γ γ from standard model predictions, and direct search for excited neutrino. A new interaction, parametrized by a 4-fermion contact term, cell, is studied in lepton pair production reactions, assuming different chiralities of the currents. Lower limits on the compositeness scale Λ are obtained by fitting model predictions to the data. They are in the range from 1 to a few TeV depending on model and lepton flavour. Researches for the lightest excited particle that could be the excited neutrino, are presented

  8. Enhanced luminescence in SrMgAl(x)O(17±δ):yMn4+ composite phosphors.

    Science.gov (United States)

    Cao, Renping; Sharafudeen, Kaniyarakkal N; Qiu, Jianrong

    2014-01-03

    Red-emitting SrMgAlxO17±δ:yMn(4+) composite phosphors (x=10-100; y=0.05-4.0 mol%) are synthesized by solid-state reaction method in air. Addition of Al2O3 leads to the formation of two concomitant phases, i.e., SrMgAl10O17 and Al2O3 phases in the composite phosphor. Red emission from Mn(4+) ions in the composite phosphors is greatly enhanced due to multiple scattering and absorption of excitation light between SrMgAl10O17 and Al2O3 phases. SrMgAlxO17±δ:yMn(4+) composite phosphors would be a promising candidate as red phosphor in the application of a 397 nm near UV-based W-LED. Copyright © 2013 Elsevier B.V. All rights reserved.

  9. Preparation of WO3/g-C3N4 composites and their application in oxidative desulfurization

    Science.gov (United States)

    Zhao, Rongxiang; Li, Xiuping; Su, Jianxun; Gao, Xiaohan

    2017-01-01

    WO3/graphitic carbon nitride (g-C3N4) composites were successfully synthesized through direct calcining of a mixture of WO3 and g-C3N4 at 400 °C for 2 h. The WO3 was prepared by calcination of phosphotungstic acid at 550 °C for 4 h, and the g-C3N4 was obtained by calcination of melamine at 520 °C for 4 h. The WO3/g-C3N4 composites were characterized by X-ray diffraction (XRD), Scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FT-IR), and Brunner-Emmett-Teller analysis (BET). The WO3/g-C3N4 composites exhibited stronger XRD peaks of WO3 and g-C3N4 than the WO3 and pure g-C3N4. In addition, two WO3 peaks at 25.7° and 26.6° emerged for the 36% -WO3/g-C3N4 composite. This finding indicated that WO3 was highly dispersed on the surface of the g-C3N4 nanosheets and interacted with the nanosheets, which resulted in the appearance of (012) and (022) planes of WO3. The WO3/g-C3N4 composite also exhibited a larger specific surface area and higher degree of crystallization than WO3 or pure g-C3N4, which resulted in high catalytic activity of the catalyst. Desulfurization experiments demonstrated that the desulfurization rate of dibenzothiophene (DBT) in model oil reached 91.2% under optimal conditions. Moreover, the activity of the catalyst was not significantly decreased after five recycles.

  10. Commissioning and Performance of the ATLAS Inner Detector with proton-proton Collisions at the LHC

    CERN Document Server

    Limosani, A; The ATLAS collaboration

    2010-01-01

    The ATLAS Inner Detector is a composite tracking system consisting of silicon pixels, silicon strips and straw tubes in a 2 T magnetic field. Its installation was completed in August 2008 and the detector has taken part in datataking with colliding LHC beams. Utilising collision data we present studies of the individual sub-systems, which include measurements of the Lorentz angle, timing, noise characteristics and cluster reconstruction efficiency. We also report results of the post collision alignment of the detector geometry and probe the agreement between data and simulation in the early stages of track reconstruction at ATLAS.

  11. Study of RPC bakelite electrodes and detector performance for INO-ICAL

    International Nuclear Information System (INIS)

    Kumar, A.; Gaur, A.; Hasbuddin, Md.; Kumar, P.; Kumar, P.; Kaur, D.; Mishra, S.; Naimuddin, Md.

    2014-01-01

    The Resistive Plate Chambers (RPCs) are going to be used as the active detectors in the India-based Neutrino Observatory (INO)-Iron Calorimeter (ICAL) experiment for the detection and study of atmospheric neutrinos. In this paper, an extensive study of structural and electrical properties for different kind of bakelite RPC electrodes is presented. RPCs fabricated from these electrodes are tested for their detector efficiency and noise rate. The study concludes with the variation of efficiency, leakage current and counting rate over the period of operation with different gas compositions and operational conditions like temperature and relative humidity

  12. Dose measurements with a HPGe detector - a technical manual

    Energy Technology Data Exchange (ETDEWEB)

    Lidstroem, K.; Nordenfors, C.; Aagren, G

    2000-06-01

    This paper is a technical manual for estimations of dose based on a gamma spectrum. The method used is based on the Monte Carlo code EGS4. Since dose estimations from spectra are specific for each detector, this work is performed on two mobile HPGe detectors at FOA NBC Defence in Umeaa. This technical manual describes the method used in three steps: Part 1 explains how to construct a model of the detector geometry and the specific material for a new detector. Part 2 describes the underlying work of Monte Carlo simulations of a detector given geometry and material. Part 3 describes dose estimations from a gamma spectrum.

  13. Layered Composite of TiC-TiB2 to Ti-6Al-4V in Graded Composition by Combustion Synthesis in High-gravity Field

    International Nuclear Information System (INIS)

    Huang Xuegang; Zhao Zhongmin; Zhang Long

    2013-01-01

    By taking combustion synthesis to prepare solidified TiB 2 matrix ceramic in high-gravity field, the layered composite of TiC-TiB 2 ceramic to Ti-6Al-4V substrate in graded composition was achieved. XRD, FESEM and EDS results showed that the bulk full-density solidified TiC-TiB 2 composite was composed of fine TiB 2 platelets, TiC irregular grains, a few of α-Al 2 O 3 inclusions and Cr alloy phases, and α'-Ti phases alternating with Ti-enriched carbides constituted the matrix of the joint in which fine TiB platelets were embedded, whereas some C, B atoms were also detected at the heat-affected zone of Ti-6A1-4V substrate. The layered composite of the solidified ceramic to Ti-6Al-4V substrate in graded composition with continuous microstructure was considered a result of fused joint and inter-diffusion between liquid ceramic and surface-molten Ti alloy, followed by TiB 2 -Ti peritectic reaction and subsequent eutectic reaction in TiC-TiB-Ti ternary system.

  14. A Detector for (n,gamma) Cross Section Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Hellstroem, J; Beshai, S

    1971-09-15

    A new detector to be used for determining total (n,gamma) cross sections has been developed in this laboratory. The detector is a large liquid scintillator of approximately 4pi geometry. When used in an experiment the overall time resolution was found to be 10 ns

  15. Development of sintered composites CaSO4 doped with Dy and Nd

    International Nuclear Information System (INIS)

    Chagas, M.A.P.; Parente, L.J.; Souza, D.N.

    2007-01-01

    The main of this work was the developing of sintered composites in order to use as thermoluminescent dosimeters using a simple route to preparation, employing high temperature. The composites were prepared with CaSO 4 .2H 2 O doped with Dy 2 O 3 and NdO 3 . Initially CaSO 4 .2H 2 O was dehydrated in oven at 100 deg C by 1h. After the addiction dopants and homogenization of compounds, PVA was incorporated to make easy to compaction of composites. The pellets with 6 mm of diameter and 1 mm thickness were sintered at 900 deg C and 1000 deg C by 6 h. The TL emission showed two peaks when the samples were irradiated with beta source (Sr 90 +Y 90 ). In all cases, the calibration curves presented responses proportional to absorbed dose. The results showed that this material have potential to be used in dosimetry. (author)

  16. A mathematical method to calculate efficiency of BF3 detectors

    International Nuclear Information System (INIS)

    Si Fenni; Hu Qingyuan; Peng Taiping

    2009-01-01

    In order to calculate absolute efficiency of the BF 3 detector, MCNP/4C code is applied to calculate relative efficiency of the BF 3 detector first, and then absolute efficiency is figured out through mathematical techniques. Finally an energy response curve of the BF 3 detector for 1-20 MeV neutrons is derived. It turns out that efficiency of BF 3 detector are relatively uniform for 2-16 MeV neutrons. (authors)

  17. Performance of Geant4 in simulating semiconductor particle detector response in the energy range below 1 MeV

    Science.gov (United States)

    Soti, G.; Wauters, F.; Breitenfeldt, M.; Finlay, P.; Kraev, I. S.; Knecht, A.; Porobić, T.; Zákoucký, D.; Severijns, N.

    2013-11-01

    Geant4 simulations play a crucial role in the analysis and interpretation of experiments providing low energy precision tests of the Standard Model. This paper focuses on the accuracy of the description of the electron processes in the energy range between 100 and 1000 keV. The effect of the different simulation parameters and multiple scattering models on the backscattering coefficients is investigated. Simulations of the response of HPGe and passivated implanted planar Si detectors to β particles are compared to experimental results. An overall good agreement is found between Geant4 simulations and experimental data.

  18. ATLAS Pixel Detector Design For HL-LHC

    CERN Document Server

    Smart, Ben; The ATLAS collaboration

    2016-01-01

    The ATLAS Inner Detector will be replaced for the High-Luminosity LHC (HL-LHC) running in 2026. The new Inner Detector will be called the Inner Tracker (ITk). The ITk will cover an extended eta-range: at least to |eta|<3.2, and likely up to |eta|<4.0. The ITk will be an all-Silicon based detector, consisting of a Silicon strip detector outside of a radius of 362mm, and a Silicon pixel detector inside of this radius. Several novel designs are being considered for the ITk pixel detector, to cope with high-eta charged particle tracks. These designs are grouped into 'extended' and 'inclined' design-types. Extended designs have long pixel staves with sensors parallel to the beamline. High-eta particles will therefore hit these sensors at shallow angles, leaving elongated charge clusters. The length of such a charge cluster can be used to estimate the angle of the passing particle. This information can then be used in track reconstruction to improve tracking efficiency and reduce fake rates. Inclined designs ...

  19. Hydrogen generation behaviors of NaBH4-NH3BH3 composite by hydrolysis

    Science.gov (United States)

    Xu, Yanmin; Wu, Chaoling; Chen, Yungui; Huang, Zhifen; Luo, Linshan; Wu, Haiwen; Liu, Peipei

    2014-09-01

    In this work, NH3BH3 (AB) is used to induce hydrogen generation during NaBH4 (SB) hydrolysis in order to reduce the use of catalysts, simplify the preparation process, reduce the cost and improve desorption kinetics and hydrogen capacity as well. xNaBH4-yNH3BH3 composites are prepared by ball-milling in different proportions (from x:y = 1:1 to 8:1). The experimental results demonstrate that all composites can release more than 90% of hydrogen at 70 °C within 1 h, and their hydrogen yields can reach 9 wt% (taking reacted water into account). Among them, the composites in the proportion of 4:1 and 5:1, whose hydrogen yields reach no less than 10 wt%, show the best hydrogen generation properties. This is due to the impact of the following aspects: AB additive improves the dispersibility of SB particles, makes the composite more porous, hampers the generated metaborate from adhering to the surface of SB, and decreases the pH value of the composite during hydrolysis. The main solid byproduct of this hydrolysis system is NaBO2·2H2O. By hydrolytic kinetic simulation of the composites, the fitted activation energies of the complexes are between 37.2 and 45.6 kJ mol-1, which are comparable to the catalytic system with some precious metals and alloys.

  20. Preparation and characterization of Fe3O4@Au-C225 composite targeted nanoparticles for MRI of human glioma.

    Science.gov (United States)

    Ge, Yaoqi; Zhong, Yuejiao; Ji, Guozhong; Lu, Qianling; Dai, Xinyu; Guo, Zhirui; Zhang, Peng; Peng, Gang; Zhang, Kangzhen; Li, Yuntao

    2018-01-01

    To study the characterization of Fe3O4@Au-C225 composite targeted MNPs. Fe3O4@Au-C225 was prepared by the absorption method. The immunosorbent assay was used to evaluate its absorption efficiency at C225 Fc. ZETA SIZER3000 laser particle size analyzer, ultraviolet photometer and its characteristics were analyzed by VSM. the targeting effect of Fe3O4@Au-C225 composite targeted MNPs on U251 cells in vitro were detected by 7.0 Tesla Micro-MR; and subcutaneous transplanted human glioma in nude mice were performed the targeting effect in vivo after tail vein injection of Fe3O4@Au-C225 composite targeted MNPs by MRI. The self-prepared Fe3O4@Au composite MNPs can adsorb C225 with high efficiency of adsorption so that Fe3O4@Au-C225 composite targeted MNPs were prepared successfully. Fe3O4@Au-C225 composite targeted MNPs favorably targeted human glioma cell line U251 in vitro; Fe3O4@Au-C225 composite targeted MNPs have good targeting ability to xenografted glioma on nude mice in vivo, and can be traced by MRI. The Fe3O4@Au-C225 composite targeted MNPs have the potential to be used as a tracer for glioma in vivo.

  1. Stilbene crystalline powder in polymer base as a new fast neutron detector

    International Nuclear Information System (INIS)

    Budakovsky, S.V.; Galunov, N.Z.; Grinyov, B.V.; Karavaeva, N.L.; Kyung Kim, Jong; Kim, Yong-Kyun; Pogorelova, N.V.; Tarasenko, O.A.

    2007-01-01

    A new organic scintillation material consisting of stilbene grains in a polymer glue base is presented. The crystalline grains of stilbene are obtained by mechanical grinding of stilbene single crystals. The resulting composite scintillators have been studied as detectors for fast neutrons

  2. Mobility and powering of large detectors. Moving large detectors

    International Nuclear Information System (INIS)

    Thompson, J.

    1977-01-01

    The possibility is considered of moving large lepton detectors at ISABELLE for readying new experiments, detector modifications, and detector repair. A large annex (approximately 25 m x 25 m) would be built adjacent to the Lepton Hall separated from the Lepton Hall by a wall of concrete 11 m high x 12 m wide (for clearance of the detector) and approximately 3 m thick (for radiation shielding). A large pad would support the detector, the door, the cryogenic support system and the counting house. In removing the detector from the beam hall, one would push the pad into the annex, add a dummy beam pipe, bake out the beam pipe, and restack and position the wall on a small pad at the door. The beam could then operate again while experimenters could work on the large detector in the annex. A consideration and rough price estimate of various questions and proposed solutions are given

  3. Absolute Standardization Of 90Sr Using 4 pi(PC) Detector

    International Nuclear Information System (INIS)

    Pujadi; Wardiyanto, Gatot; Wijaya I, Nazar; Sudarsono

    2000-01-01

    Standardization of exp.90 Sr with absolute measurement using 4 pi proporsional detector has been carried out. The counting efficiency of beta particle mainly depends on self and VYNS absorption. The correction of self absorption were determined by means of the beta maximum energy vs. absorption curve. Self absorption value of exp.90 Sr with Emax. 0,55 MeV is 2,5%, and exp.90 Y with Emax. 2,28% MeV is 0,5%. The VYNS absorptions were determined by counting using variations of VYNS thickness. The corrections of VYNS are 0,70% at Eeta max. 0,55 MeV and 0,1% at Ebeta max. 2,28 MeV, for every VYNS sheet having thickness of n 15 mugr/cm exp.2. The samples were made from the source without dilution, and with dilution factors of 6,9 and 9,9. The activity of samples were determined by counting using two methods, with and without variation of VYNS thickness. The result of measurement by variation dilution of solution and VYNS thickness is fairly good, the difference is 1,68%. The difference between result of activity measurement of exp.90 Sr with this methods and the activity of master solution is fairly good, with the discrepancies are from 0,5 to 1,16%

  4. Volume 10 No. 4 April 2010 2379 NUTRIENT COMPOSITION AND ...

    African Journals Online (AJOL)

    Administrator

    2010-04-04

    Apr 4, 2010 ... This study examined the nutrient composition and sensory properties of fruit juice produced from ... processed into juice with appreciable nutritive value and acceptable sensory properties. Key words: .... (11.5%) respectively were higher than that reported for sweet orange 45 kcal and 10.5%, respectively [1] ...

  5. Borehole Muon Detector Development

    Science.gov (United States)

    Bonneville, A.; Flygare, J.; Kouzes, R.; Lintereur, A.; Yamaoka, J. A. K.; Varner, G. S.

    2015-12-01

    Increasing atmospheric CO2 concentrations have spurred investigation into carbon sequestration methods. One of the possibilities being considered, storing super-critical CO2 in underground reservoirs, has drawn more attention and pilot projects are being supported worldwide. Monitoring of the post-injection fate of CO2 is of utmost importance. Generally, monitoring options are active methods, such as 4D seismic reflection or pressure measurements in monitoring wells. We propose here to develop a 4-D density tomography of subsurface CO2 reservoirs using cosmic-ray muon detectors deployed in a borehole. Muon detection is a relatively mature field of particle physics and there are many muon detector designs, though most are quite large and not designed for subsurface measurements. The primary technical challenge preventing deployment of this technology in the subsurface is the lack of miniaturized muon-tracking detectors capable of fitting in standard boreholes and that will resist the harsh underground conditions. A detector with these capabilities is being developed by a collaboration supported by the U.S. Department of Energy. Current simulations based on a Monte Carlo modeling code predict that the incoming muon angle can be resolved with an error of approximately two degrees, using either underground or sea level spectra. The robustness of the design comes primarily from the use of scintillating rods as opposed to drift tubes. The rods are arrayed in alternating layers to provide a coordinate scheme. Preliminary testing and measurements are currently being performed to test and enhance the performance of the scintillating rods, in both a laboratory and a shallow underground facility. The simulation predictions and data from the experiments will be presented.

  6. Small area detectors at the European XFEL

    Science.gov (United States)

    Turcato, M.; Gessler, P.; Hauf, S.; Kuster, M.; Meyer, M.; Nordgren, J.; Sztuk-Dambietz, J.; Youngman, C.

    2014-05-01

    The detectors to be used at the European XFEL have to deal with the unique time structure of the machine, delivering up to 2700 pulses, with a repetition rate of 4.5 MHz, ten times per second, the very high photon flux and the need to combine single-photon sensitivity and a large dynamic range. This represents a challenge not only for the large-area 2D imaging detectors but also for the smaller-area detectors and makes the use of standard commercial devices impossible. Dedicated solutions are therefore envisaged for small imaging- or strip-detectors. In this contribution the focus is put on two particular small-area detector solutions which are planned to be used at the European XFEL, a strip detector for hard X-rays (with energy 3 < E < 25 keV) and an imaging detector for soft X-rays (0.25 < E < 3 keV). Hard X-rays photon-beam diagnostics as well as hard X-ray absorption and emission spectroscopy at the European XFEL make use of strip detectors as detectors for beam spectrometers or as energy-dispersive detectors in combination with an energy-dispersive element. The European XFEL is establishing cooperation with the Paul Scherrer Institute in Villigen to develop a new version of the Gotthard detector best suited to the European XFEL needs. The use case and the required detector specifications are illustrated. Starting from the present detector version, the modifications planned to adapt it to the European XFEL running conditions are described. These include the capability of running at an increased rate and to provide a veto signal to the large 2D imaging detectors, in order to be able to remove non-interesting images already at early stages of the DAQ system. In another particular application, resonant inelastic X-ray scattering, a Micro-Channel Plate detector matched to a delay-line readout is foreseen to be used. In this case the European XFEL is aiming for a highly customized solution provided by the German company Surface Concept. The use case is described

  7. Preliminary evaluation of a novel energy-resolved photon-counting gamma ray detector.

    Science.gov (United States)

    Meng, L-J; Tan, J W; Spartiotis, K; Schulman, T

    2009-06-11

    In this paper, we present the design and preliminary performance evaluation of a novel energy-resolved photon-counting (ERPC) detector for gamma ray imaging applications. The prototype ERPC detector has an active area of 4.4 cm × 4.4 cm, which is pixelated into 128 × 128 square pixels with a pitch size of 350 µm × 350µm. The current detector consists of multiple detector hybrids, each with a CdTe crystal of 1.1 cm × 2.2 cm × 1 mm, bump-bonded onto a custom-designed application-specific integrated circuit (ASIC). The ERPC ASIC has 2048 readout channels arranged in a 32 × 64 array. Each channel is equipped with pre- and shaping-amplifiers, a discriminator, peak/hold circuitry and an analog-to-digital converter (ADC) for digitizing the signal amplitude. In order to compensate for the pixel-to-pixel variation, two 8-bit digital-to-analog converters (DACs) are implemented into each channel for tuning the gain and offset. The ERPC detector is designed to offer a high spatial resolution, a wide dynamic range of 12-200 keV and a good energy resolution of 3-4 keV. The hybrid detector configuration provides a flexible detection area that can be easily tailored for different imaging applications. The intrinsic performance of a prototype ERPC detector was evaluated with various gamma ray sources, and the results are presented.

  8. Four channel Cosmic Ray detector based on polymaq

    Science.gov (United States)

    Herrera-Guzman, K. N.; Gutierrez-Sanchez, R. A.; Felix, J.

    2017-01-01

    The Cherenkov radiation has been widely studied in transparent materials, and applied to detect and identify elementary particles. But it has not been widely studied in opaque materials. A four channels radiation detector has been designed, built, characterized, and operated; based on four polymaq (UHMW-PE) bars of 2.54 cm X 5.08 cm X 25.4 cm, which is an opaque material to visible radiation to the human eye. Silicon photo detectors, Hamamatsu, avalanche type (APD) are used to detect the radiation produced by the passage of particles in the detector blocks. The design, construction, characterization, operation, and preliminary results of this cosmic ray detector details are presented.

  9. The 150 ns detector project: Prototype preamplifier results

    Science.gov (United States)

    Warburton, W. K.; Russell, S. R.; Kleinfelder, Stuart A.

    1994-08-01

    The long-term goal of the 150 ns detector project is to develop a pixel area detector capable of 6 MHz frame rates (150 ns/frame). Our milestones toward this goal are: a single pixel, 1×256 1D and 8×8 2D detectors, 256×256 2D detectors and, finally, 1024 × 1024 2D detectors. The design strategy is to supply a complete electronics chain (resetting preamp, selectable gain amplifier, analog-to-digital converter (ADC), and memory) for each pixel. In the final detectors these will all be custom integrated circuits. The front-end preamplifiers are integrated first, since their design and performance are the most unusual and also critical to the project's success. Similarly, our early work is concentrated on devising and perfecting detector structures. In this paper we demonstrate the performance of prototypes of our integrated preamplifiers. While the final design will have 64 preamps to a chip, including a switchable gain stage, the prototypes were integrated 8 channels to a "Tiny Chip" and tested in 4 configurations (feedback capacitor Cf equal 2.5 or 4.0 pF, output directly or through a source follower). These devices have been tested thoroughly for reset settling times, gain, linearity, and electronic noise. They generally work as designed, being fast enough to easily integrate detector charge, settle, and reset in 150 ns. Gain and linearity appear to be acceptable. Current values of electronic noise, in double-sampling mode, are about twice the design goal of {2}/{3} of a single photon at 6 keV. We expect this figure to improve with the addition of the onboard amplifier stage and improved packaging. Our next test chip will include these improvements and allow testing with our first detector samples, which will be 1×256 (50 μm wide pixels) and 8×8 (1 mm 2 pixels) element detector on 1 mm thick silicon.

  10. LISe pixel detector for neutron imaging

    Energy Technology Data Exchange (ETDEWEB)

    Herrera, Elan; Hamm, Daniel [Department of Nuclear Engineering, University of Tennessee, Knoxville, TN (United States); Wiggins, Brenden [Technology Development, Y-12 National Security Complex, Oak Ridge, TN (United States); Department of Physics and Astronomy, Vanderbilt University, Nashville, TN (United States); Milburn, Rob [Department of Nuclear Engineering, University of Tennessee, Knoxville, TN (United States); Burger, Arnold [Department of Physics and Astronomy, Vanderbilt University, Nashville, TN (United States); Department of Life and Physical Sciences, Fisk University, Nashville, TN (United States); Bilheux, Hassina [Chemical and Engineering Materials Division, Oak Ridge National Laboratory, Oak Ridge, TN (United States); Santodonato, Louis [Instrument and Source Division, Oak Ridge National Laboratory, Oak Ridge National Laboratory, Oak Ridge, TN (United States); Chvala, Ondrej [Department of Nuclear Engineering, University of Tennessee, Knoxville, TN (United States); Stowe, Ashley [Department of Nuclear Engineering, University of Tennessee, Knoxville, TN (United States); Technology Development, Y-12 National Security Complex, Oak Ridge, TN (United States); Department of Physics and Astronomy, Vanderbilt University, Nashville, TN (United States); Lukosi, Eric, E-mail: elukosi@utk.edu [Department of Nuclear Engineering, University of Tennessee, Knoxville, TN (United States)

    2016-10-11

    Semiconducting lithium indium diselenide, {sup 6}LiInSe{sub 2} or LISe, has promising characteristics for neutron detection applications. The 95% isotopic enrichment of {sup 6}Li results in a highly efficient thermal neutron-sensitive material. In this study, we report on a proof-of-principle investigation of a semiconducting LISe pixel detector to demonstrate its potential as an efficient neutron imager. The LISe pixel detector had a 4×4 of pixels with a 550 µm pitch on a 5×5×0.56 mm{sup 3} LISe substrate. An experimentally verified spatial resolution of 300 µm was observed utilizing a super-sampling technique.

  11. Elastic-plastic analysis of AS4/PEEK composite laminate using a one-parameter plasticity model

    Science.gov (United States)

    Sun, C. T.; Yoon, K. J.

    1992-01-01

    A one-parameter plasticity model was shown to adequately describe the plastic deformation of AS4/PEEK (APC-2) unidirectional thermoplastic composite. This model was verified further for unidirectional and laminated composite panels with and without a hole. The elastic-plastic stress-strain relations of coupon specimens were measured and compared with those predicted by the finite element analysis using the one-parameter plasticity model. The results show that the one-parameter plasticity model is suitable for the analysis of elastic-plastic deformation of AS4/PEEK composite laminates.

  12. Nonlinear analysis of AS4/PEEK thermoplastic composite laminate using a one parameter plasticity model

    Science.gov (United States)

    Sun, C. T.; Yoon, K. J.

    1990-01-01

    A one-parameter plasticity model was shown to adequately describe the orthotropic plastic deformation of AS4/PEEK (APC-2) unidirectional thermoplastic composite. This model was verified further for unidirectional and laminated composite panels with and without a hole. The nonlinear stress-strain relations were measured and compared with those predicted by the finite element analysis using the one-parameter elastic-plastic constitutive model. The results show that the one-parameter orthotropic plasticity model is suitable for the analysis of elastic-plastic deformation of AS4/PEEK composite laminates.

  13. Mechanical Properties and Fabrication of Nanostructured Mg_2SiO_4-MgAl_2O_4 Composites by High-Frequency Induction Heated Combustion

    International Nuclear Information System (INIS)

    Shon, In-Jin; Kang, Hyun-Su; Hong, Kyung-Tae; Doh, Jung-Mann; Yoon, Jin-Kook

    2011-01-01

    Nanopowders of MgO, Al_2O_3 and SiO_2 were made by high energy ball milling. The rapid sintering of nanostructured MgAl_2O_4-Mg_2SiO_4 composites was investigated by a high-frequency induction heating sintering process. The advantage of this process is that it allows very quick densification to near theoretical density and inhibition of grain growth. Nanocrystalline materials have received much attention as advanced engineering materials with improved physical and mechanical properties. As nanomaterials possess high strength, high hardness, excellent ductility and toughness, undoubtedly, more attention has been paid for the application of nanomaterials. Highly dense nanostructured MgAl_2O_4-Mg_2SiO_4 composites were produced with simultaneous application of 80 MPa pressure and induced output current of total power capacity (15 kW) within 2 min. The sintering behavior, gain size and mechanical properties of MgAl_2O_4-Mg_2SiO_4 composites were investigated.

  14. Report on neutral particle detectors and QED: PEP summer study

    International Nuclear Information System (INIS)

    Bloom, E.D.; Bulos, F.; Buschhorn, G.

    1974-08-01

    The exploration of the neutral particle final states in e + e/sup /minus// annihilation using a 4π neutral particle detector is discussed. Charge particle final state physics is also considered in the context of a neutral detector. Design criteria are discussed, and a possible detector design is presented. 15 refs., 13 figs., 2 tabs

  15. Facile One-Step Sonochemical Synthesis and Photocatalytic Properties of Graphene/Ag3PO4 Quantum Dots Composites

    Science.gov (United States)

    Reheman, Abulajiang; Tursun, Yalkunjan; Dilinuer, Talifu; Halidan, Maimaiti; Kadeer, Kuerbangnisha; Abulizi, Abulikemu

    2018-03-01

    In this study, a novel graphene/Ag3PO4 quantum dot (rGO/Ag3PO4 QD) composite was successfully synthesized via a facile one-step photo-ultrasonic-assisted reduction method for the first time. The composites were analyzed by various techniques. According to the obtained results, Ag3PO4 QDs with a size of 1-4 nm were uniformly dispersed on rGO nanosheets to form rGO/Ag3PO4 QD composites. The photocatalytic activity of rGO/Ag3PO4 QD composites was evaluated by the decomposition of methylene blue (MB). Meanwhile, effects of the surfactant dosage and the amount of rGO on the photocatalytic activity were also investigated. It was found that rGO/Ag3PO4 QDs (WrGO:Wcomposite = 2.3%) composite exhibited better photocatalytic activity and stability with degrading 97.5% of MB within 5 min. The improved photocatalytic activities and stabilities were majorly related to the synergistic effect between Ag3PO4 QDs and rGO with high specific surface area, which gave rise to efficient interfacial transfer of photogenerated electrons and holes on both materials. Moreover, possible formation and photocatalytic mechanisms of rGO/Ag3PO4 QDs were proposed. The obtained rGO/Ag3PO4 QDs photocatalysts would have great potentials in sewage treatment and water splitting.

  16. CVD diamond detectors for ionizing radiation

    Science.gov (United States)

    Friedl, M.; Adam, W.; Bauer, C.; Berdermann, E.; Bergonzo, P.; Bogani, F.; Borchi, E.; Brambilla, A.; Bruzzi, M.; Colledani, C.; Conway, J.; Dabrowski, W.; Delpierre, P.; Deneuville, A.; Dulinski, W.; van Eijk, B.; Fallou, A.; Fizzotti, F.; Foulon, F.; Gan, K. K.; Gheeraert, E.; Grigoriev, E.; Hallewell, G.; Hall-Wilton, R.; Han, S.; Hartjes, F.; Hrubec, J.; Husson, D.; Kagan, H.; Kania, D.; Kaplon, J.; Karl, C.; Kass, R.; Knöpfle, K. T.; Krammer, M.; Logiudice, A.; Lu, R.; Manfredi, P. F.; Manfredotti, C.; Marshall, R. D.; Meier, D.; Mishina, M.; Oh, A.; Pan, L. S.; Palmieri, V. G.; Pernegger, H.; Pernicka, M.; Peitz, A.; Pirollo, S.; Polesello, P.; Pretzl, K.; Re, V.; Riester, J. L.; Roe, S.; Roff, D.; Rudge, A.; Schnetzer, S.; Sciortino, S.; Speziali, V.; Stelzer, H.; Stone, R.; Tapper, R. J.; Tesarek, R.; Thomson, G. B.; Trawick, M.; Trischuk, W.; Vittone, E.; Walsh, A. M.; Wedenig, R.; Weilhammer, P.; Ziock, H.; Zoeller, M.; RD42 Collaboration

    1999-10-01

    In future HEP accelerators, such as the LHC (CERN), detectors and electronics in the vertex region of the experiments will suffer from extreme radiation. Thus radiation hardness is required for both detectors and electronics to survive in this harsh environment. CVD diamond, which is investigated by the RD42 Collaboration at CERN, can meet these requirements. Samples of up to 2×4 cm2 have been grown and refined for better charge collection properties, which are measured with a β source or in a testbeam. A large number of diamond samples has been irradiated with hadrons to fluences of up to 5×10 15 cm-2 to study the effects of radiation. Both strip and pixel detectors were prepared in various geometries. Samples with strip metallization have been tested with both slow and fast readout electronics, and the first diamond pixel detector proved fully functional with LHC electronics.

  17. Implantation of a 4πγ, with well type Nal(Tl) detector, for calibration of gamma emitters radionuclides

    International Nuclear Information System (INIS)

    Barros, Douglas Cisneiros de

    2001-04-01

    Among the absolute calibration methods for activity quantity of radionuclides the most used in the metrology laboratories are: the 4πβγ coincidence counting), defined solid angle counting, sum-peak (or γ-γ coincidence) and 4π γ method. The 4πγ method is appropriate to measure the activity of radionuclides with complex decay scheme and its implementation at Laboratorio Nacional de Metrologia das Radiacoes Ionizantes, commissioned by INMETRO from 1989, will provide to the expansion of the jobs to supply the users by standard radioactive sources. The determination of activity can be made using calibration factor and/or the efficiency curve. For the implantation of this calibration method at LNMRI, after the selection of the detector and the electronic instrumentation, the attainment of the efficiency curve in function of gamma rays energy, standard sources with one or two peaks each were used. The method is based in ε Τ = Πι (1 - ε ΤΕ ι) where ΕΤ is the total efficiency for each radionuclide and eTi is the efficiency for each gamma transition of this radionuclide. The detector selected was a 8 x 8'' well type Nal(Tl), with well dimensions 6'' deep and 3'' of diameter, from Harshaw The standards sources used are: Am-241, Pb- 210, Mn-54, Co-57, Cd-109, Ce-139, Co-60, Na-22, Y-88 and Zn-65. The preliminary results are consistent with the literature. (author)

  18. Uso de detectores de neutrinos para el monitoreo de reactores nucleares Uso de detectores de neutrinos para el monitoreo de reactores nucleares

    Directory of Open Access Journals (Sweden)

    Gerardo Moreno

    2012-02-01

    Full Text Available Se estudia la factibilidad del uso de los detectores de antineutrinos para el monitoreo de reactores nucleares. Usando un modelo sencillo de cascada de fisión a dos componentes, se ilustra la dependencia del número de antineutrinos detectados a una distancia L del reactor según la composición nuclear del combustible. Se explica el principio de detección de neutrinos de reactores en base al decaimiento beta inverso y se describe como los detectores de neutrinos pueden emplearse para el monitoreo de la producción de materiales fisibles en el reactor. Se comenta como generalizar este análisis al caso real de un reactor nuclear in situ y uno de los principales experimentos internacionales dedicados a este propósito. We study the feasibility to use antineutrinos detectors for monitoring of nuclear reactors. Using a simple model of fission shower with two components, we illustrate how the numbers of antineutrinos detected at a distance L from the reactor depend on the composition of the nuclear combustible. We explain the principles of reactor neutrino detection using inverse beta decays and we describe how neutrinos detectors can be used for monitoring the production of fissile materials within the reactors. We comment how to generalize this analysis to the realistic case of a nuclear reactor in situ and one of the main international experiments dedicated to study the use of neutrinos detectors as nuclear safeguards.

  19. Determination of the KQclinfclin,Qmsr fmsr correction factors for detectors used with an 800 MU/min CyberKnife(®) system equipped with fixed collimators and a study of detector response to small photon beams using a Monte Carlo method.

    Science.gov (United States)

    Moignier, C; Huet, C; Makovicka, L

    2014-07-01

    detectors were in good agreement with OFMC,w except for the 5 mm field size (about -7.5% for the diamond and +3% for the SFD). A good agreement with OFMC,w was obtained with the EBT2 film and micro-LiF dosimeters (deviation less than 1.4% for all fields investigated). [Formula: see text] correction factors for several detectors used in this work have been calculated. The impact of atomic composition on the dosimetric response of detectors was found to be insignificant, unlike the mass density and size of the detecting material. The results obtained with the passive dosimeters showed that they can be used for small beam OF measurements without correction factors. The study of detector response showed that ORdet is depending on the mass density, the volume averaging, and the coating effects of the detecting material. Each effect was quantified for the PTW 60016 and 60017 diodes, the micro-LiF, and the PTW 60003 diamond detectors. None of the active detectors used in this work can be recommended as a reference for small field dosimetry, but an improved diode detector with a smaller silicon chip coated with tissue-equivalent material is anticipated (by simulation) to be a reliable small field dosimetric detector in a nonequilibrium field.

  20. 2011 ATLAS Detector Performance - ID and Forward detectors

    CERN Document Server

    Davies‎, E; The ATLAS collaboration; Abdel Khalek, S

    2012-01-01

    This poster describes the performance of 2 parts of ATLAS: - The Inner Detector which consists of 3 subdetectors: the Pixel detector, the SemiConductor Tracker (or SCT) and the Transition Radiation Tracker (or TRT). Here, we report on Pixel detector and SCT performance over 2011. - ALFA detector which will determine the absolute luminosity of the CERN LHC at the ATLAS Interaction Point (IP), and the total proton-proton cross section, by tracking elastically scattered protons at very small angles in the limit of the Coulomb Nuclear interference region.