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Sample records for fast transition detector

  1. A fast high-voltage current-peak detection system for the ALICE transition radiation detector

    Energy Technology Data Exchange (ETDEWEB)

    Verclas, Robert [Physikalisches Institut, Ruprecht-Karls-Universitaet Heidelberg (Germany); Collaboration: ALICE-Collaboration

    2016-07-01

    During LHC operation in run 1, the gaseous detectors of ALICE occasionally experienced simultaneous trips in their high voltage which affected the majority of the high voltage channels. These trips are caused by large anode currents in the detector and are potentially related to LHC machine operations. We developed and installed a fast current-peak detection system for the ALICE Transition Radiation Detector. This system is based on FPGA technology and monitors 144 out 522 high voltage channels minimally invasively at a maximum readout rate of 2 MHz. It is an integral part of the LHC beam monitoring system. We report on the latest status.

  2. Preamplifier-shaper prototype for the Fast Transition Detector of the Compressed Baryonic Matter (CBM) experiment at FAIR

    CERN Document Server

    Soltveit, Hans Kristian

    2007-01-01

    In this work a preamplifier-shaper prototype for the Fast Transition Detector of the Compressed BaryonicMatter (CBM) experiment at FAIR fabricated using a 0.35 μm CMOS technology will be presented. The ASIC integrates 16 identical Charge Sensitive Amplifiers (CSA) followed by a Pole-Zero network, two bridged-T filters, Common-Mode FeedBack (CMFB) network and two non-inverting level shifting stages. The circuit is optimized for a detector capacitance Cd of (5-10)pF. Measurement results confirm the noise of 330 e− + 12 e−/pF obtained in simulations for a pulse with a Full Width Half Maximum (FWHM) of 71 ns. The circuit recovers to the baseline within 200 ns. The conversion gain is 12.64 mV/fC. An integral nonlinearity of 0.7% is also achieved. The maximum output swing is 2 V. The power consumption is 16 mW/channel where the main contributors are the input transistor and the level shifting stage with 5.3 mW and 6.6 mW, respectively. The total area of the chip is 12 mm2. Although the circuit was designed for...

  3. ALICE Transition Radiation Detector

    CERN Multimedia

    Pachmayer, Y

    2013-01-01

    The Transition Radiation Detector (TRD) is the main electron detector in ALICE. In conduction with the TPC and the ITS, it provides the necessary electron identification capability to study: - Production of light and heavy vector mesons as well as the continuum in the di-electron channel, - Semi leptonic decays of hadrons with open charm and open beauty via the single-electron channel using the displaced vertex information provided by the ITS, - Correlated DD and BB pairs via coincidences of electrons in the central barrel and muons in the forward muon arm, - Jets with high Pτ tracks in one single TRD stack.

  4. Fast Timing for Collider Detectors

    CERN Multimedia

    CERN. Geneva

    2017-01-01

    Advancements in fast timing particle detectors have opened up new possibilities to design collider detectors that fully reconstruct and separate event vertices and individual particles in the time domain. The applications of these techniques are considered for the physics at HL-LHC.

  5. Ultra-fast silicon detectors

    Energy Technology Data Exchange (ETDEWEB)

    Sadrozinski, H. F.-W., E-mail: hartmut@scipp.ucsc.edu [Santa Cruz Institute for Particle Physics, UC Santa Cruz, Santa Cruz, CA 95064 (United States); Ely, S.; Fadeyev, V.; Galloway, Z.; Ngo, J.; Parker, C.; Petersen, B.; Seiden, A.; Zatserklyaniy, A. [Santa Cruz Institute for Particle Physics, UC Santa Cruz, Santa Cruz, CA 95064 (United States); Cartiglia, N.; Marchetto, F. [INFN Torino, Torino (Italy); Bruzzi, M.; Mori, R.; Scaringella, M.; Vinattieri, A. [University of Florence, Department of Physics and Astronomy, Sesto Fiorentino, Firenze (Italy)

    2013-12-01

    We propose to develop a fast, thin silicon sensor with gain capable to concurrently measure with high precision the space (∼10 μm) and time (∼10 ps) coordinates of a particle. This will open up new application of silicon detector systems in many fields. Our analysis of detector properties indicates that it is possible to improve the timing characteristics of silicon-based tracking sensors, which already have sufficient position resolution, to achieve four-dimensional high-precision measurements. The basic sensor characteristics and the expected performance are listed, the wide field of applications are mentioned and the required R and D topics are discussed. -- Highlights: •We are proposing thin pixel silicon sensors with 10's of picoseconds time resolution. •Fast charge collection is coupled with internal charge multiplication. •The truly 4-D sensors will revolutionize imaging and particle counting in many applications.

  6. ALICE Transition Radiation Detector (TRD), test beam.

    CERN Multimedia

    2003-01-01

    Electrons and positrons can be discriminated from other charged particles using the emission of transition radiation - X-rays emitted when the particles cross many layers of thin materials. To develop such a Transition Radiation Detector(TRD) for ALICE many detector prototypes were tested in mixed beams of pions and electrons, as in the example shown here.

  7. Sensors for ultra-fast silicon detectors

    Energy Technology Data Exchange (ETDEWEB)

    Sadrozinski, H.F.-W., E-mail: hartmut@scipp.ucsc.edu [Santa Cruz Institute for Particle Physics, UC Santa Cruz, Santa Cruz, CA 95064 (United States); Baselga, M.; Ely, S.; Fadeyev, V.; Galloway, Z.; Ngo, J.; Parker, C.; Schumacher, D.; Seiden, A.; Zatserklyaniy, A. [Santa Cruz Institute for Particle Physics, UC Santa Cruz, Santa Cruz, CA 95064 (United States); Cartiglia, N. [INFN Torino, Torino (Italy); Pellegrini, G.; Fernández-Martínez, P.; Greco, V.; Hidalgo, S.; Quirion, D. [Centro Nacional de Microelectrónica, IMB-CNM-CSIC, Barcelona (Spain)

    2014-11-21

    We report on electrical and charge collection tests of silicon sensors with internal gain as part of our development of ultra-fast silicon detectors. Using C–V and α TCT measurements, we investigate the non-uniform doping profile of so-called low-gain avalanche detectors (LGAD). These are n-on-p pad sensors with charge multiplication due to the presence of a thin, low-resistivity diffusion layer below the junction, obtained with a highly doped implant. We compare the bias dependence of the pulse shapes of traditional sensors and of LGAD sensors with different dopant density of the diffusion layer, and extract the internal gain.

  8. Sensors for ultra-fast silicon detectors

    International Nuclear Information System (INIS)

    Sadrozinski, H.F.-W.; Baselga, M.; Ely, S.; Fadeyev, V.; Galloway, Z.; Ngo, J.; Parker, C.; Schumacher, D.; Seiden, A.; Zatserklyaniy, A.; Cartiglia, N.; Pellegrini, G.; Fernández-Martínez, P.; Greco, V.; Hidalgo, S.; Quirion, D.

    2014-01-01

    We report on electrical and charge collection tests of silicon sensors with internal gain as part of our development of ultra-fast silicon detectors. Using C–V and α TCT measurements, we investigate the non-uniform doping profile of so-called low-gain avalanche detectors (LGAD). These are n-on-p pad sensors with charge multiplication due to the presence of a thin, low-resistivity diffusion layer below the junction, obtained with a highly doped implant. We compare the bias dependence of the pulse shapes of traditional sensors and of LGAD sensors with different dopant density of the diffusion layer, and extract the internal gain

  9. Fast neutron damage in germanium detectors

    International Nuclear Information System (INIS)

    Kraner, H.W.

    1979-10-01

    The effects of fast neutron radiation damage on the performance of both Ge(Li) and Ge(HP) detectors have been studied during the past decade and will be summarized. A review of the interaction processes leading to the defect structures causing trapping will be made. The neutron energy dependence of observable damage effects will be considered in terms of interaction and defect production cross sections

  10. Particle identification via transition radiation and detectors

    International Nuclear Information System (INIS)

    Egorytchev, V.; Saveliev, V.; Aplin, S.J.

    2000-01-01

    Transition radiation detectors show great promise for the purposes of lepton identification in existing and future experiments in high-energy physics such as HERA-B, ATLAS, ALICE in high-luminosity environment. More high performance can be expected in low-luminosity conditions - neutrino experiments (NOMAD), and ideal condition for the use of transition radiation detectors in flying and space high-energy experiments (AMS). This paper discusses the practical theory of transition radiation, basic equation and algorithm suitable for detailed analysis of transition radiation and optimization of transition radiation detectors in the area of experimental high-energy physics. The results are based on detailed Monte Carlo simulation of transition radiation introduced in GEANT and experimental results

  11. Particle identification via transition radiation and detectors

    CERN Document Server

    Egorytchev, V; Aplin, S J

    2000-01-01

    Transition radiation detectors show great promise for the purposes of lepton identification in existing and future experiments in high- energy physics such as HERA-B, ATLAS, ALICE in high-luminosity environment. More high performance can be expected in low-luminosity conditions-neutrino experiments (NOMAD), and the ideal condition for the use of transition radiation detectors in flying and space high- energy experiments (AMS). This paper discusses the practical theory of transition radiation, basic equation and algorithm suitable for detailed analysis of transition radiation and optimization of transition radiation detectors in the area of experimental high- energy physics. The results are based on detailed Monte Carlo simulation of transition radiation introduced in GEANT and experimental results. (12 refs).

  12. Fast microchannel plate detector for particles

    International Nuclear Information System (INIS)

    Wurz, P.; Gubler, L.

    1996-01-01

    In this article we report on the timing capabilities of a new microchannel plate detector we designed and built. The detector assembly has an impedance-matched transition line (50 Ω line resistance) from anode to cable connector which is considerably smaller than other, commercially available solutions and at the same time has about four times the active area. The detector was tested with an alpha particle source and excellent time response was achieved. Using 10 μm pore size channel plates, a rise time of 300 ps and a pulse width of 520 ps are obtained. The details of the signal analysis are also given in the article. copyright 1996 American Institute of Physics

  13. Fast timing readout for silicon strip detectors

    International Nuclear Information System (INIS)

    Jhingan, A.; Saneesh, N.; Kumar, M.

    2016-01-01

    The development and performance of a 16 channel hybrid fast timing amplifier (FTA), for extracting timing information from silicon strip detectors (SSD), is described. The FTA will be used in a time of flight (TOF) measurement, in which one SSD is used to obtain the ion velocity (A) as well as the energy information of a scattered particle. The TOF information with a thin transmission SSD, acting as ΔE detector (Z) in a detector telescope, will provide a unique detection system for the identification of reaction products in the slowed down beam campaign of low energy branch (LEB) at NUSTAR-FAIR. Such a system will also provide large solid angle coverage with ~ 100% detection efficiency, and adequate segmentation for angular information. A good timing resolution (≤ 100 ps) enables to have shorter flight paths, thus a closely packed 4π array should be feasible. Preamplifiers for energy readout in SSD are easily available. A major constraint with SSDs is the missing high density multichannel preamplifiers which can provide both fast timing as well as energy. Provision of both timing and energy processing, generally makes circuit bulky, with higher power consumption, which may not be suitable in SSD arrays. In case of DSSSD, the problem was overcome by using timing from one side and energy from the other side. A custom designed 16 channel FTA has been developed for DSSSD design W from Micron Semiconductors, UK

  14. A fast readout system for scintillation detectors

    International Nuclear Information System (INIS)

    Steijger, J.; Kok, E.; Kwakkel, E.; Visschers, J.L.; Zwart, A.N.M.

    1991-01-01

    A system of fast readout electronics for segmented scintillation detectors has been constructed and is now operational. Instead of delaying the analog signals in long coaxial cables, they are digitized immediately and stored in dual-port memories, while the trigger decision is being made. A VMEbus system collects the data from these memories on the data acquisition modules within one crate. Several VME crates are connected via a transputer network to transport the data to an event builder. A separate transputer network is used to perform the VME cycles, needed for the computer-controlled tuning of the experiment. (orig.)

  15. Fast CsI-phoswich detector

    International Nuclear Information System (INIS)

    Langenbrunner, J.R.

    1996-01-01

    An improved phoswich radiation detector used pure CsI crystal and a fast plastic scintillator and a single photomultiplier tube. The plastic is arranged to receive incident radiation, and that which passed through then strikes the CsI crystal. Scintillation light from both the plastic and CsI crystal are applied to the photomultiplier tube, with the light from the plastic passing through the crystal without absorption therein. Electronics are provided for analyzing the output of the photomultiplier tube to discriminate responses due to the plastic and the CsI crystal, through short gate and long gate integration, to produce results which are indicative of the characteristics of the different types of incident radiation, even in the presence of large amounts of radiation. The phoswich detector has excellent timing resolution. The scintillators of the CsI- phoswich were chosen for their fast risetimes, of about 3 ns for NE102A, and 30 ns for the pure CsI. 5 figs

  16. Development of Optical Fiber Detector for Measurement of Fast Neutron

    International Nuclear Information System (INIS)

    YAGI, Takahiro; KAWAGUCHI, Shinichi; MISAWA, Tsuyoshi; PYEON, Cheol Ho; UNESAKI, Hironobu; SHIROYA, Seiji; OKAJIMA, Shigeaki; TANI, Kazuhiro

    2008-01-01

    Measurement of fast neutron flux is important for investigation of characteristic of fast reactors. In order to insert a neutron detector in a narrow space such as a gap of between fuel plates and measure the fast neutrons in real time, a neutron detector with an optical fiber has been developed. This detector consists of an optical fiber whose tip is covered with mixture of neutron converter material and scintillator such as ZnS(Ag). The detector for fast neutrons uses ThO 2 as converter material because 232 Th makes fission reaction with fast neutrons. The place where 232 Th can be used is limited by regulations because 232 Th is nuclear fuel material. The purpose of this research is to develop a new optical fiber detector to measure fast neutrons without 232 Th and to investigate the characteristic of the detector. These detectors were used to measure a D-T neutron generator and fast neutron flux distribution at Fast Critical Assembly. The results showed that the fast neutron flux distribution of the new optical fiber detector with ZnS(Ag) was the same as it of the activation method, and the detector are effective for measurement of fast neutrons. (authors)

  17. Foam radiators for transition radiation detectors

    International Nuclear Information System (INIS)

    Chernyatin, V.; Dolgoshein, B.; Gavrilenko, I.; Potekhin, M.; Romaniouk, A.; Sosnovtsev, V.

    1993-01-01

    A wide variety of foam radiators, potentially useful in the design of a transition radiation detector, the possible particle identification tool in collider experiments, have been tested in the beam. Various characteristics of these radiators are compared, and the conclusion is reached that certain brands of polyethylene foam are best suited for use in the detector. Comparison is made with a 'traditional' radiator, which is a periodic structure of plastic foils. (orig.)

  18. PAMELA Space Mission: The Transition Radiation Detector

    Science.gov (United States)

    Ambriola, M.; Bellotti, R.; Cafagna, F.; Circella, M.; De Marzo, C.; Giglietto, N.; Marangelli, B.; Mirizzi, N.; Romita, M.; Spinelli, P.

    2003-07-01

    PAMELA telescope is a satellite-b orne magnetic spectrometer built to fulfill the primary scientific objectives of detecting antiparticles (antiprotons and positrons) in the cosmic rays, and to measure spectra of particles in cosmic rays. The PAMELA telescope is currently under integration and is composed of: a silicon tracker housed in a permanent magnet, a time of flight and an anticoincidence system both made of plastic scintillators, a silicon imaging calorimeter, a neutron detector and a Transition Radiation Detector (TRD). The TRD detector is composed of 9 sensitive layers of straw tubes working in proportional mode for a total of 1024 channels. Each layer is interleaved with a radiator plane made of carbon fibers. The TRD detector characteristics will be described along with its performance studied exposing the detector to particle beams of electrons, pions, muons and protons of different momenta at both CERN-PS and CERN-SPS facilities.

  19. Fast neutron activating detectors for pulsed flow measurements

    International Nuclear Information System (INIS)

    Dyatlov, V.D.; Kunaev, G.T.; Popytaev, A.N.; Cheremukhov, B.V.

    1979-01-01

    The requirements to the activation detectors of the pulsed flows of the fast neutrons are considered; the criteria of optimum measurement time, geometrical moderator sizes and radioactive detector element properties have been obtained. On their analysis parameter selection has been carried out. The neutron detector to register the short pulses has been designed and calibrated. The ways of further increase of sensitivity and efficiency of such detectors are discussed

  20. The transition radiation detector of the CBM experiment at FAIR

    Energy Technology Data Exchange (ETDEWEB)

    Bergmann, Cyrano [Institut fuer Kernphysik, WWU Muenster (Germany)

    2016-07-01

    The Compressed Baryonic Matter (CBM) experiment is a fixed target heavy-ion experiment at the future FAIR accelerator facility. The CBM Transition Radiation Detector (TRD) is one of the key detectors to provide electron identification above momenta of 1 GeV/c and charged particle tracking. Due its capability to identify charged particles via their specific energy loss, the TRD in addition will provide valuable information for the measurement of fragments. These requirements can be fulfilled with a XeCO{sub 2} based Multi-Wire Proportional Counter (MWPC) detector in combination with an adequate radiator. The default MWPC is composed of a symmetric amplification area of 7 mm thickness, followed by a 5 mm drift region to enhance the TR-photon absorption probability in the active gas volume. This geometry provides also efficient and fast signal creation, as well as read-out, of the order of 200 μs per charged particle track. The performance of this detector is maximized by reducing the material budget between the radiator and gas volume to a minimum. The full detector at SIS100 will be composed of 200 modules in 2 sizes. To limit cost and production time the number of various module types is limited to 6 types and 4 types of Front End Board (FEB) flavors are required. An overview of the design and performance of the TRD detector is given.

  1. A fast neutron detector with IP by track measurement

    International Nuclear Information System (INIS)

    Miao Zhengqiang; Yang Jun; Zhang Qiang; Zhao Xiangfeng; Wang Daohua

    2004-01-01

    Imaging Plate(IP) is very sensitive to electric particles, especially to heavy ions. As we know, the recoiling protons are produced while fast neutrons scattered in light material containing hydrogen. When the recoiling proton enters in the sensitive layer of IP, a track will be recorded by IP. In this paper, a fast neutron detector based on IP and (n, p) reaction is described in detail, the detector's efficiency is studied also. (authors)

  2. The AMS-02 transition radiation detector

    CERN Document Server

    Kirn, Th

    2004-01-01

    The Alpha Magnetic Spectrometer AMS02 will be equipped with a large transition radiation detector (TRD) to achieve a proton background suppression necessary for dark matter searches. The AMS02 TRD consists of 20 layers of fleece radiator each with Xe/CO//2 proportional wire straw tubes read out by a dedicated low-power data- acquisition system. A space-qualified TRD design will be presented. The performance of a 20-layer prototype was tested at CERN with electron, myon and pion beams up to l00 GeV and with protons up to 250 GeV. The beam-test results will be compared to Geant3 MC predictions. The detector is under construction at RWTH Aachen; the gas system will be built at MIT, slow-control at MIT and INFN Rome and DAQ at TH Karlsruhe. This project is funded by the German Space Agency DLR, the US Department of Energy DOE and NASA.

  3. Semi-insulating GaAs detectors of fast neutrons

    International Nuclear Information System (INIS)

    Sagatova, A.; Sedlackova, K.; Necas, V.; Zatko, B.; Dubecky, F.; Bohacek, P.

    2012-01-01

    The present work deals with the technology of HDPE neutron conversion layer application on the surface of semi-insulating (SI) GaAs detectors via developed polypropylene (PP) based glue. The influence of glue deposition on the electric properties of the detectors was studied as well as the ability of the detectors to register the fast neutrons from "2"3"9Pu-Be neutron source. (authors)

  4. Fast-timing methods for semiconductor detectors

    International Nuclear Information System (INIS)

    Spieler, H.

    1982-03-01

    The basic parameters are discussed which determine the accuracy of timing measurements and their effect in a practical application, specifically timing with thin-surface barrier detectors. The discussion focusses on properties of the detector, low-noise amplifiers, trigger circuits and time converters. New material presented in this paper includes bipolar transistor input stages with noise performance superior to currently available FETs, noiseless input terminations in sub-nanosecond preamplifiers and methods using transmission lines to couple the detector to remotely mounted preamplifiers. Trigger circuits are characterized in terms of effective rise time, equivalent input noise and residual jitter

  5. Fast timing methods for semiconductor detectors. Revision

    International Nuclear Information System (INIS)

    Spieler, H.

    1984-10-01

    This tutorial paper discusses the basic parameters which determine the accuracy of timing measurements and their effect in a practical application, specifically timing with thin-surface barrier detectors. The discussion focusses on properties of the detector, low-noise amplifiers, trigger circuits and time converters. New material presented in this paper includes bipolar transistor input stages with noise performance superior to currently available FETs, noiseless input terminations in sub-nanosecond preamplifiers and methods using transmission lines to couple the detector to remotely mounted preamplifiers. Trigger circuits are characterized in terms of effective rise time, equivalent input noise and residual jitter

  6. Measurements of fast neutrons by bubble detectors

    Energy Technology Data Exchange (ETDEWEB)

    Castillo, F.; Martinez, H. [Laboratorio de Espectroscopia, Instituto de Ciencias Fisicas, Universidad Nacional Autonoma de Mexico, Apartado Postal 48-3, 62251, Cuernavaca Morelos (Mexico); Leal, B. [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Apartado Postal 70-543, 04510, Ciudad Universitaria, Mexico D. F. (Mexico); Rangel, J. [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Apartado Postal 70-543, 04510, Ciudad Universitaria, Mexico D. F (Mexico); Reyes, P. G. [Facultad de Ciencias, Universidad Autonoma del Estado de Mexico, Instituto Literario 100, Col. Centro, 50000, Toluca Estado de Mexico (Mexico)

    2013-07-03

    Neutron bubble detectors have been studied using Am-Be and D-D neuron sources, which give limited energy information. The Bubble Detector Spectrometer (BDS) have six different energy thresholds ranging from 10 KeV to 10 Mev. The number of bubbles obtained in each measurement is related to the dose (standardized response R) equivalent neutrons through sensitivity (b / {mu}Sv) and also with the neutron flux (neutrons per unit area) through a relationship that provided by the manufacturer. Bubble detectors were used with six different answers (0.11 b/ {mu}Sv, 0093 b/{mu}Sv, 0.14 b/{mu}Sv, 0.17 b/{mu}Sv, 0051 b/{mu}Sv). To test the response of the detectors (BDS) radiate a set of six of them with different energy threshold, with a source of Am-Be, placing them at a distance of one meter from it for a few minutes. Also, exposed to dense plasma focus Fuego Nuevo II (FN-II FPD) of ICN-UNAM, apparatus which produces fusion plasma, generating neutrons by nuclear reactions of neutrons whose energy emitting is 2.45 MeV. In this case the detectors were placed at a distance of 50 cm from the pinch at 90 Degree-Sign this was done for a certain number of shots. In both cases, the standard response is reported (Dose in {mu}Sv) for each of the six detectors representing an energy range, this response is given by the expression R{sub i}= B{sub i} / S{sub i} where B{sub i} is the number of bubbles formed in each and the detector sensitivity (S{sub i}) is given for each detector in (b / {mu}Sv). Also, reported for both cases, the detected neutron flux (n cm{sup -2}), by a given ratio and the response involves both standardized R, as the average cross section sigma. The results obtained have been compared with the spectrum of Am-Be source. From these measurements it can be concluded that with a combination of bubble detectors, with different responses is possible to measure the equivalent dose in a range of 10 to 100 {mu}Sv fields mixed neutron and gamma, and pulsed generated fusion

  7. 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

  8. Fast method for geometric calibration of detectors and matching testing between two detectors

    International Nuclear Information System (INIS)

    Pechenova, O.Yu.

    2002-01-01

    A fast method of geometric calibration of detectors has been proposed. The main idea of this method is to determine offsets by fitting the real data distribution by analytic functions which describe the motion of one detector relative to the other one. This method can be applicable to offsets determination for one detector relative to the other detector or for one part of the detector relative to its other part. The detectors should be placed perpendicular to the beam axis. The form of analytic functions depends on the geometry of the experiment and direction of the coordinate axes. The analytic functions have been obtained using the rotation matrices. This method can be applied to the matching testing between two detectors

  9. Conceptual design of the ITER fast-ion loss detector

    International Nuclear Information System (INIS)

    Garcia-Munoz, M.; Ayllon-Guerola, J.; Galdon, J.; Garcia Lopez, J.; Gonzalez-Martin, J.; Jimenez-Ramos, M. C.; Rodriguez-Ramos, M.; Rivero-Rodriguez, J. F.; Sanchis-Sanchez, L.; Kocan, M.; Bertalot, L.; Bonnet, Y.; Casal, N.; Giacomin, T.; Pinches, S. D.; Reichle, R.; Vayakis, G.; Veshchev, E.; Vorpahl, Ch.; Walsh, M.

    2016-01-01

    A conceptual design of a reciprocating fast-ion loss detector for ITER has been developed and is presented here. Fast-ion orbit simulations in a 3D magnetic equilibrium and up-to-date first wall have been carried out to revise the measurement requirements for the lost alpha monitor in ITER. In agreement with recent observations, the simulations presented here suggest that a pitch-angle resolution of ∼5° might be necessary to identify the loss mechanisms. Synthetic measurements including realistic lost alpha-particle as well as neutron and gamma fluxes predict scintillator signal-to-noise levels measurable with standard light acquisition systems with the detector aperture at ∼11 cm outside of the diagnostic first wall. At measurement position, heat load on detector head is comparable to that in present devices.

  10. Conceptual design of the ITER fast-ion loss detector

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Munoz, M., E-mail: mgm@us.es; Ayllon-Guerola, J.; Galdon, J.; Garcia Lopez, J.; Gonzalez-Martin, J.; Jimenez-Ramos, M. C.; Rodriguez-Ramos, M.; Rivero-Rodriguez, J. F.; Sanchis-Sanchez, L. [Department of Atomic, Molecular and Nuclear Physics, University of Seville, 41012 Seville (Spain); CNA (Universidad de Sevilla-CSIC-J. Andalucía), Seville (Spain); Kocan, M.; Bertalot, L.; Bonnet, Y.; Casal, N.; Giacomin, T.; Pinches, S. D.; Reichle, R.; Vayakis, G.; Veshchev, E.; Vorpahl, Ch.; Walsh, M. [ITER Organization, Route de Vinon-sur-Verdon, CS 90 046, 13067 Saint Paul-lez-Durance Cedex (France); and others

    2016-11-15

    A conceptual design of a reciprocating fast-ion loss detector for ITER has been developed and is presented here. Fast-ion orbit simulations in a 3D magnetic equilibrium and up-to-date first wall have been carried out to revise the measurement requirements for the lost alpha monitor in ITER. In agreement with recent observations, the simulations presented here suggest that a pitch-angle resolution of ∼5° might be necessary to identify the loss mechanisms. Synthetic measurements including realistic lost alpha-particle as well as neutron and gamma fluxes predict scintillator signal-to-noise levels measurable with standard light acquisition systems with the detector aperture at ∼11 cm outside of the diagnostic first wall. At measurement position, heat load on detector head is comparable to that in present devices.

  11. Lifetime measurements in transitional nuclei by fast electronic scintillation timing

    Science.gov (United States)

    Caprio, M. A.; Zamfir, N. V.; Casten, R. F.; Amro, H.; Barton, C. J.; Beausang, C. W.; Cooper, J. R.; Gürdal, G.; Hecht, A. A.; Hutter, C.; Krücken, R.; McCutchan, E. A.; Meyer, D. A.; Novak, J. R.; Pietralla, N.; Ressler, J. J.; Berant, Z.; Brenner, D. S.; Gill, R. L.; Regan, P. H.

    2002-10-01

    A new generation of experiments studying nuclei in spherical-deformed transition regions has been motivated by the introduction of innovative theoretical approaches to the treatment of these nuclei. The important structural signatures in the transition regions, beyond the basic yrast level properties, involve γ-ray transitions between low-spin, non-yrast levels, and so information on γ-ray branching ratios and absolute matrix elements (or level lifetimes) for these transitions is crucial. A fast electronic scintillation timing (FEST) system [H. Mach, R. L. Gill, and M. Moszyński, Nucl. Instrum. Methods A 280, 49 (1989)], making use of BaF2 and plastic scintillation detectors, has been implemented at the Yale Moving Tape Collector for the measurement of lifetimes of states populated in β^ decay. Experiments in the A100 (Pd, Ru) and A150 (Dy, Yb) regions have been carried out, and a few examples will be presented. Supported by the US DOE under grants and contracts DE-FG02-91ER-40609, DE-FG02-88ER-40417, and DE-AC02-98CH10886 and by the German DFG under grant Pi 393/1.

  12. R&D on a new type of micropattern gaseous detector: The Fast Timing Micropattern detector

    Energy Technology Data Exchange (ETDEWEB)

    Abbaneo, D.; Abbas, M. [CERN, Geneva (Switzerland); Abbrescia, M. [INFN Bari and University of Bari, Bari (Italy); Akl, M. Abi [Texas A& M University at Qatar, Doha (Qatar); Aboamer, O. [Academy of Scientific Research and Technology, Egyptian Network of High Energy Physics, ASRT-ENHEP, Cairo (Egypt); Acosta, D. [University of Florida, Gainesville (United States); Ahmad, A. [National Center for Physics, Quaid-i-Azam University Campus, Islamabad (Pakistan); Ahmed, W. [INFN Bari and University of Bari, Bari (Italy); Aleksandrov, A. [Institute for Nuclear Research and Nuclear Energy, Sofia (Bulgaria); Altieri, P. [INFN Bari and University of Bari, Bari (Italy); Asawatangtrakuldee, C. [Peking University, Beijing (China); Aspell, P. [CERN, Geneva (Switzerland); Assran, Y. [Academy of Scientific Research and Technology, Egyptian Network of High Energy Physics, ASRT-ENHEP, Cairo (Egypt); Awan, I. [National Center for Physics, Quaid-i-Azam University Campus, Islamabad (Pakistan); Bally, S. [CERN, Geneva (Switzerland); Ban, Y. [Peking University, Beijing (China); Banerjee, S. [Saha Institute of Nuclear Physics, Kolkata (India); Barashko, V. [University of Florida, Gainesville (United States); Barria, P. [Universite Libre de Bruxelles, Brussels (Belgium); Bencze, G. [Institute for Particle and Nuclear Physics, Wigner Research Centre for Physics, Hungarian Academy of Sciences, Budapest (Hungary); and others

    2017-02-11

    This contribution introduces a new type of Micropattern Gaseous Detector, the Fast Timing Micropattern (FTM) detector, utilizing fully Resistive WELL structures. The structure of the prototype will be described in detail and the results of the characterization study performed with an X-ray gun will be presented, together with the first results on time resolution based on data collected with muon/pion test beams.

  13. Study on the fast neutron sensitivity of thermoluminescent detectors

    International Nuclear Information System (INIS)

    Szabo, P.P.; Palfalvi, J.

    1984-03-01

    Fast neutron (14.7 MeV) sensitivity of several thermoluminescent detectors was determined. The investigated detectors were MTS-N type pellets (made in Poland) used routinely in the authors' institute for personnel dosimetry, 7 LiF powder used for accident dosimetry, CaSO 4 :Dy and CaSO 4 :Tm powders (made in Hungary) used for enviromental monitoring and space dosimetry. Both free-in-air and on-phantom irradiations were performed. The new results are compared with responses calculated and measured earlier. (author)

  14. Model for cryogenic particle detectors with superconducting phase transition thermometers

    International Nuclear Information System (INIS)

    Proebst, F.; Frank, M.; Cooper, S.; Colling, P.; Dummer, D.; Ferger, P.; Nucciotti, A.; Seidel, W.; Stodolsky, L.

    1994-09-01

    We present data on a detector composed of an 18 g Si crystal and a superconducting phase transition thermometer which could be operated over a wide temperature range. An energy resolution of 1 keV (FWHM) has been obtained for 60 keV photons. The signals consist of two components: A fast one and a slow one, with decay times of 1.5 ms and 30-60 ms, respectively. In this paper we present a simple model which takes thermal and non-thermal phonon processes into account and provides a description of the observed temperature dependence of the pulse shape. The fast component, which completely dominates the signal at low temperatures, is due to high-frequency non-thermal phonons being absorbed in the thermometer. Thermalization of these phonons then leads to a temperature rise of the absorber, which causes the slow thermal component. At the highest operating temperatures (T∼80 mK) the amplitude of the slow component is roughly as expected from the heat capacity of the absorber. The strong suppression of the slow component at low temperatures is explained mostly as a consequence of the weak thermal coupling between electrons and phonons in the thermometer at low temperatures. (orig.)

  15. 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)

  16. 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)

  17. Practical prototype of a cluster-counting transition radiation detector

    Energy Technology Data Exchange (ETDEWEB)

    Fabjan, C W; Willis, W [European Organization for Nuclear Research, Geneva (Switzerland); Gavrilenko, I; Maiburov, S; Shmeleva, A; Vasiliev, P [AN SSSR, Moscow. Fizicheskij Inst.; Chernyatin, V; Dolgoshein, B; Kantserov, V; Nevski, P [Moskovskij Inzhenerno-Fizicheskij Inst. (USSR)

    1981-06-15

    A transition radiation detector using a method of cluster counting measurements has been tested. The performance is considerably better than with the usual method of total charge measurements, as well as offering advantages in simplicity of construction and operation.

  18. The ALICE Transition Radiation Detector: construction, operation, and performance

    OpenAIRE

    Acharya, Shreyasi; Adam, Jaroslav; Ahmad, Nazeer; Bhattacharjee, Buddhadeb; Turrisi, Rosario; Tveter, Trine Spedstad; Ullaland, Kjetil; Umaka, Ejiro Naomi; Uras, Antonio; Usai, Gianluca; Utrobicic, Antonija; Vala, Martin; Van Der Maarel, Jasper; Van Hoorne, Jacobus Willem; Bhom, Jihyun

    2018-01-01

    The Transition Radiation Detector (TRD) was designed and built to enhance the capabilities of the ALICE detector at the Large Hadron Collider (LHC). While aimed at providing electron identification and triggering, the TRD also contributes significantly to the track reconstruction and calibration in the central barrel of ALICE. In this paper the design, construction, operation, and performance of this detector are discussed. A pion rejection factor of up to 410 is achieved at a momentum of 1 G...

  19. A large area transition radiation detector for the NOMAD experiment

    Science.gov (United States)

    Bassompierre, G.; Bermond, M.; Berthet, M.; Bertozzi, T.; Détraz, C.; Dubois, J.-M.; Dumps, L.; Engster, C.; Fazio, T.; Gaillard, G.; Gaillard, J.-M.; Gouanère, M.; Manola-Poggioli, E.; Mossuz, L.; Mendiburu, J.-P.; Nédélec, P.; Palazzini, E.; Pessard, H.; Petit, P.; Petitpas, P.; Placci, A.; Sillou, D.; Sottile, R.; Valuev, V.; Verkindt, D.; Vey, H.; Wachnik, M.

    1998-02-01

    A transition radiation detector to identify electrons at 90% efficiency with a rejection factor against pions of 10 3 on an area of 2.85 × 2.85 m 2 has been constructed for the NOMAD experiment. Each of its 9 modules includes a 315 plastic foil radiator and a detector plane of 176 vertical straw tubes filled with a xenon-methane gas mixture. Details of the design, construction and operation of the detector are given.

  20. A large area transition radiation detector for the NOMAD experiment

    CERN Document Server

    Bassompierre, Gabriel; Berthet, M; Bertozzi, T; Détraz, C; Dubois, J M; Dumps, Ludwig; Engster, Claude; Fazio, T; Gaillard, G; Gaillard, Jean-Marc; Gouanère, M; Manola-Poggioli, E; Mossuz, L; Mendiburu, J P; Nédélec, P; Palazzini, E; Pessard, H; Petit, P; Petitpas, P; Placci, Alfredo; Sillou, D; Sottile, R; Valuev, V Yu; Verkindt, D; Vey, H; Wachnik, M

    1997-01-01

    A transition radiation detector to identify electrons at 90% efficiency with a rejection factor against pions of 10 3 on an area of 2.85 × 2.85 m 2 has been constructed for the NOMAD experiment. Each of its 9 modules includes a 315 plastic foil radiator and a detector plane of 176 vertical straw tubes filled with a xenon-methane gas mixture. Details of the design, construction and operation of the detector are given.

  1. Fast neutron detection using solid state nuclear track detectors

    International Nuclear Information System (INIS)

    Vilela, E.C.

    1990-01-01

    CR-39 and Makrofol-E solid state nuclear track detectors were studied aiming their application to fast neutron detection. Optimum etching conditions of those two kinds of materials were determined the followings - the Makrofol-E detector is electrochemically etched in a PEW solution (15% KOH, 40% ethilic alcohol and 45% water) for 2 h., with an applied electric field strength of 30 kV/cm (r/m/s/) and frequency of 2 kHz, at room temperature; - the CR-39 detector is chemically pre-etched during 1 h in a 20% (w/v) NaOH solution at 70 sup(0)C, followed by 13 h electrochemical etch using the same solution at room temperature and an electric field strength of 30 kV/cm (r.m.s.) and frequency of 2 kHz.(E.G.)

  2. Fast rise time IR detectors for lepton colliders

    International Nuclear Information System (INIS)

    Drago, A.; Bini, S.; Guidi, M. Cestelli; Marcelli, A.; Pace, E.

    2016-01-01

    Diagnostics is a fundamental issue for accelerators whose demands are continuously increasing. In particular bunch-by-bunch diagnostics is a key challenge for the latest generation of lepton colliders and storage rings. The Frascati Φ-factory, DAΦNE, colliding at 1.02 GeV in the centre of mass, hosts in the main rings few synchrotron radiation beamlines and two of them collect the synchrotron radiation infrared emission: SINBAD from the electron ring and 3+L from the positron ring. At DAΦNE each bucket is 2.7 ns long and particles are gathered in bunches emitting pulsed IR radiation, whose intensity in the long wavelength regime is directly proportional to the accumulated particles. Compact uncooled photoconductive HgCdTe detectors have been tested in both beamlines using dedicated optical layouts. Actually, the fast rise time of HgCdTe semiconductors give us the chance to test bunch-by-bunch devices for both longitudinal and transverse diagnostics. For the longitudinal case, single pixel detectors have been used, while for the transverse diagnostics, multi-pixel array detectors, with special custom design, are under test. This contribution will briefly describe the status of the research on fast IR detectors at DAΦNE, the results obtained and possible foreseen developments.

  3. Ionization signals from diamond detectors in fast-neutron fields

    Energy Technology Data Exchange (ETDEWEB)

    Weiss, C. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); CIVIDEC Instrumentation, Wien (Austria); Frais-Koelbl, H. [University of Applied Sciences, Wiener Neustadt (Austria); Griesmayer, E.; Kavrigin, P. [CIVIDEC Instrumentation, Wien (Austria); Vienna University of Technology, Wien (Austria)

    2016-09-15

    In this paper we introduce a novel analysis technique for measurements with single-crystal chemical vapor deposition (sCVD) diamond detectors in fast-neutron fields. This method exploits the unique electronic property of sCVD diamond sensors that the signal shape of the detector current is directly proportional to the initial ionization profile. In fast-neutron fields the diamond sensor acts simultaneously as target and sensor. The interaction of neutrons with the stable isotopes {sup 12}C and {sup 13}C is of interest for fast-neutron diagnostics. The measured signal shapes of detector current pulses are used to identify individual types of interactions in the diamond with the goal to select neutron-induced reactions in the diamond and to suppress neutron-induced background reactions as well as γ-background. The method is verified with experimental data from a measurement in a 14.3 MeV neutron beam at JRC-IRMM, Geel/Belgium, where the {sup 13}C(n, α){sup 10}Be reaction was successfully extracted from the dominating background of recoil protons and γ-rays and the energy resolution of the {sup 12}C(n, α){sup 9}Be reaction was substantially improved. The presented analysis technique is especially relevant for diagnostics in harsh radiation environments, like fission and fusion reactors. It allows to extract the neutron spectrum from the background, and is particularly applicable to neutron flux monitoring and neutron spectroscopy. (orig.)

  4. Compositionality for Markov reward chains with fast and silent transitions

    NARCIS (Netherlands)

    Markovski, J.; Sokolova, A.; Trcka, N.; Vink, de E.P.

    2009-01-01

    A parallel composition is defined for Markov reward chains with stochastic discontinuity, and with fast and silent transitions. In this setting, compositionality with respect to the relevant aggregation preorders is established. For Markov reward chains with fast transitions the preorders are

  5. The investigation of fast neutron Threshold Activation Detectors (TAD)

    International Nuclear Information System (INIS)

    Gozani, T; King, M J; Stevenson, J

    2012-01-01

    The detection of fast neutrons is usually done by liquid hydrogenous organic scintillators, where the separation between the ever present gamma rays and neutrons is achieved by the pulse shape discrimination (PSD). In many practical situation the detection of fast neutrons has to be carried out while the intense source (be it neutrons, gamma rays or x-rays) that creates these neutrons, for example by the fission process, is present. This source, or ''flash'', usually blinds the neutron detectors and temporarily incapacitates them. By the time the detectors recover the prompt neutron signature does not exist. Thus to overcome the blinding background, one needs to search for processes whereby the desired signature, such as fission neutrons could in some way be measured long after the fission occurred and when the neutron detector is fully recovered from the overload. A new approach was proposed and demonstrated a good sensitivity for the detection of fast neutrons in adverse overload situations where normally it could not be done. A temporal separation of the fission event from the prompt neutrons detection is achieved via the activation process. The main idea, called Threshold Activation Detection (or detector)-TAD, is to find appropriate substances that can be selectively activated by the fission neutrons and not by the source radiation, and then measure the radioactively decaying activation products (typically beta and γ-rays) well after the source pulse has ended. The activation material should possess certain properties: a suitable half-life; an energy threshold below which the numerous source neutrons will not activate it (e.g. about 3 MeV); easily detectable activation products and has a usable cross section for the selected reaction. Ideally the substance would be part of the scintillator. There are several good candidates for TAD. The first one we have selected is based on fluorine. One of the major advantages of this element is the fact that it is a major

  6. The investigation of fast neutron Threshold Activation Detectors (TAD)

    Science.gov (United States)

    Gozani, T.; King, M. J.; Stevenson, J.

    2012-02-01

    The detection of fast neutrons is usually done by liquid hydrogenous organic scintillators, where the separation between the ever present gamma rays and neutrons is achieved by the pulse shape discrimination (PSD). In many practical situation the detection of fast neutrons has to be carried out while the intense source (be it neutrons, gamma rays or x-rays) that creates these neutrons, for example by the fission process, is present. This source, or ``flash'', usually blinds the neutron detectors and temporarily incapacitates them. By the time the detectors recover the prompt neutron signature does not exist. Thus to overcome the blinding background, one needs to search for processes whereby the desired signature, such as fission neutrons could in some way be measured long after the fission occurred and when the neutron detector is fully recovered from the overload. A new approach was proposed and demonstrated a good sensitivity for the detection of fast neutrons in adverse overload situations where normally it could not be done. A temporal separation of the fission event from the prompt neutrons detection is achieved via the activation process. The main idea, called Threshold Activation Detection (or detector)-TAD, is to find appropriate substances that can be selectively activated by the fission neutrons and not by the source radiation, and then measure the radioactively decaying activation products (typically beta and γ-rays) well after the source pulse has ended. The activation material should possess certain properties: a suitable half-life; an energy threshold below which the numerous source neutrons will not activate it (e.g. about 3 MeV); easily detectable activation products and has a usable cross section for the selected reaction. Ideally the substance would be part of the scintillator. There are several good candidates for TAD. The first one we have selected is based on fluorine. One of the major advantages of this element is the fact that it is a major

  7. Fabrication of Ultrasensitive Transition Edge Sensor Bolometric Detectors for HIRMES

    Science.gov (United States)

    Brown, Ari-David; Brekosky, Regis; Franz, David; Hsieh, Wen-Ting; Kutyrev, Alexander; Mikula, Vilem; Miller, Timothy; Moseley, S. Harvey; Oxborrow, Joseph; Rostem, Karwan; hide

    2017-01-01

    The high resolution mid-infrared spectrometer (HIRMES) is a high resolving power (R approx. 100,000) instrument operating in the 25-122 micron spectral range and will fly on board the Stratospheric Observatory for Far-Infrared Astronomy (SOFIA) in 2019. Central ot HIRMES are its two transition edge sensor (TES) bolometric cameras, an 8x16 detector high resolution array and a 64x16 detector low resolution array. Both types of detectors consist of MoAu TES fabricated on leg-isolated Si membranes. Whereas the high resolution detectors, with noise equivalent power (NEP) approx. 2 aW/square root of (Hz), are fabricated on 0.45 micron Si substrates, the low resolution detectors, with NEP approx. 10 aW/square root of (Hz), are fabricated on 1.40 micron Si. Here we discuss the similarities and difference in the fabrication methodologies used to realize the two types of detectors.

  8. Self powered neutron detectors as in-core detectors for Sodium-cooled Fast Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Verma, V., E-mail: vasudha.verma@physics.uu.se [Division of Applied Nuclear Physics, Uppsala University, Box 516, SE-75120 Uppsala (Sweden); CEA, DEN, DER, Instrumentation Sensors and Dosimetry Laboratory, Cadarache, F-13108 St-Paul-lez-Durance (France); Barbot, L.; Filliatre, P. [CEA, DEN, DER, Instrumentation Sensors and Dosimetry Laboratory, Cadarache, F-13108 St-Paul-lez-Durance (France); Hellesen, C. [Division of Applied Nuclear Physics, Uppsala University, Box 516, SE-75120 Uppsala (Sweden); Jammes, C. [CEA, DEN, DER, Instrumentation Sensors and Dosimetry Laboratory, Cadarache, F-13108 St-Paul-lez-Durance (France); Svärd, S. Jacobsson [Division of Applied Nuclear Physics, Uppsala University, Box 516, SE-75120 Uppsala (Sweden)

    2017-07-11

    Neutron flux monitoring system forms an integral part of the design of a Generation IV sodium cooled fast reactor. Diverse possibilities of detector system installation must be studied for various locations in the reactor vessel in order to detect any perturbations in the core. Results from a previous paper indicated that it is possible to detect changes in neutron source distribution initiated by an inadvertent withdrawal of outer control rod with in-vessel fission chambers located azimuthally around the core. It is, however, not possible to follow inner control rod withdrawal and precisely know the location of the perturbation in the core. Hence the use of complimentary in-core detectors coupled with the peripheral fission chambers is proposed to enable robust core monitoring across the radial direction. In this paper, we assess the feasibility of using self-powered neutron detectors (SPNDs) as in-core detectors in fast reactors for detecting local changes in the power distribution when the reactor is operated at nominal power. We study the neutron and gamma contributions to the total output current of the detector modelled with Platinum as the emitter material. It is shown that this SPND placed in an SFR-like environment would give a sufficiently measurable prompt neutron induced current of the order of 600 nA/m. The corresponding induced current in the connecting cable is two orders of magnitude lower and can be neglected. This means that the SPND can follow in-core power fluctuations. This validates the operability of an SPND in an SFR-like environment. - Highlights: • Studied possibility of using SPNDs as in-core detectors in SFRs. • Study done to detect local power profile changes when reactor is at nominal power. • SPND with a Pt-emitter gives measurable prompt current of the order of 600 nA/m. • Dominant proportion of prompt response is maintained throughout the operation. • Detector signal gives dynamic information on the power fluctuations.

  9. Fast infrared detectors for beam diagnostics with synchrotron radiation

    International Nuclear Information System (INIS)

    Bocci, A.; Marcelli, A.; Pace, E.; Drago, A.; Piccinini, M.; Cestelli Guidi, M.; De Sio, A.; Sali, D.; Morini, P.; Piotrowski, J.

    2007-01-01

    Beam diagnostic is a fundamental constituent of any particle accelerators either dedicated to high-energy physics or to synchrotron radiation experiments. All storage rings emit radiations. Actually they are high brilliant sources of radiation: the synchrotron radiation emission covers from the infrared range to the X-ray domain with a pulsed structure depending on the temporal characteristics of the stored beam. The time structure of the emitted radiation is extremely useful as a tool to perform time-resolved experiments. However, this radiation can be also used for beam diagnostic to determine the beam stability and to measure the dimensions of the e - or e + beam. Because of the temporal structure of the synchrotron radiation to perform diagnostic, we need very fast detectors. Indeed, the detectors required for the diagnostics of the stored particle bunches at third generation synchrotron radiation sources and FEL need response times in the sub-ns and even ps range. To resolve the bunch length and detect bunch instabilities, X-ray and visible photon detectors may be used achieving response times of a few picoseconds. Recently, photon uncooled infrared devices optimized for the mid-IR range realized with HgCdTe semiconductors allowed to obtain sub-nanosecond response times. These devices can be used for fast detection of intense IRSR sources and for beam diagnostic. We present here preliminary experimental data of the pulsed synchrotron radiation emission of DAΦNE, the electron positron collider of the LNF laboratory of the INFN, performed with new uncooled IR detectors with a time resolution of a few hundreds of picoseconds

  10. Fast flux test facility, transition project plan

    International Nuclear Information System (INIS)

    Guttenberg, S.

    1994-01-01

    The FFTF Transition Project Plan, Revision 1, provides changes and project baseline for the deactivation activities necessary to transition the FFTF to a radiologically and industrially safe shutdown condition

  11. Fast flux test facility, transition project plan

    Energy Technology Data Exchange (ETDEWEB)

    Guttenberg, S.

    1994-11-15

    The FFTF Transition Project Plan, Revision 1, provides changes and project baseline for the deactivation activities necessary to transition the FFTF to a radiologically and industrially safe shutdown condition.

  12. Transition-radiation detectors for cosmic-ray research

    International Nuclear Information System (INIS)

    Mueller, D.; Chicago Univ., Ill.

    1975-01-01

    Transition-radiation detectors for cosmic-ray work are described which consist of plastic foam of multiple plastic foil radiators, followed by proportional chambers. A summary of the properties of such detectors is given, and the detection and discrimination efficiencies for energetic particles are discussed. Several possible applications of such devices for studies of cosmic-ray particles in the energy region γ=E/mc 2 >10 3 are advertised

  13. FastSim: A Fast Simulation for the SuperB Detector

    International Nuclear Information System (INIS)

    Andreassen, R; Sokoloff, M; Arnaud, N; Burmistrov, L; Brown, D N; Carlson, J; Gaponenko, I; Suzuki, A; Cheng, C-h; Simone, A Di; Manoni, E; Perez, A; Walsh, J; Rama, M; Roberts, D; Rotondo, M; Simi, G

    2011-01-01

    We have developed a parameterized (fast) simulation for detector optimization and physics reach studies of the proposed SuperB Flavor Factory in Italy. Detector components are modeled as thin sections of planes, cylinders, disks or cones. Particle-material interactions are modeled using simplified cross-sections and formulas. Active detectors are modeled using parameterized response functions. Geometry and response parameters are configured using xml files with a custom-designed schema. Reconstruction algorithms adapted from BaBar are used to build tracks and clusters. Multiple sources of background signals can be merged with primary signals. Pattern recognition errors are modeled statistically by randomly misassigning nearby tracking hits. Standard BaBar analysis tuples are used as an event output. Hadronic B meson pair events can be simulated at roughly 10Hz.

  14. FastSim: A Fast Simulation for the SuperB Detector

    Science.gov (United States)

    Andreassen, R.; Arnaud, N.; Brown, D. N.; Burmistrov, L.; Carlson, J.; Cheng, C.-h.; Di Simone, A.; Gaponenko, I.; Manoni, E.; Perez, A.; Rama, M.; Roberts, D.; Rotondo, M.; Simi, G.; Sokoloff, M.; Suzuki, A.; Walsh, J.

    2011-12-01

    We have developed a parameterized (fast) simulation for detector optimization and physics reach studies of the proposed SuperB Flavor Factory in Italy. Detector components are modeled as thin sections of planes, cylinders, disks or cones. Particle-material interactions are modeled using simplified cross-sections and formulas. Active detectors are modeled using parameterized response functions. Geometry and response parameters are configured using xml files with a custom-designed schema. Reconstruction algorithms adapted from BaBar are used to build tracks and clusters. Multiple sources of background signals can be merged with primary signals. Pattern recognition errors are modeled statistically by randomly misassigning nearby tracking hits. Standard BaBar analysis tuples are used as an event output. Hadronic B meson pair events can be simulated at roughly 10Hz.

  15. Fast sub-electron detectors review for interferometry

    Science.gov (United States)

    Feautrier, Philippe; Gach, Jean-Luc; Bério, Philippe

    2016-08-01

    New disruptive technologies are now emerging for detectors dedicated to interferometry. The detectors needed for this kind of applications need antonymic characteristics: the detector noise must be very low, especially when the signal is dispersed but at the same time must also sample the fast temporal characteristics of the signal. This paper describes the new fast low noise technologies that have been recently developed for interferometry and adaptive optics. The first technology is the Avalanche PhotoDiode (APD) infrared arrays made of HgCdTe. In this paper are presented the two programs that have been developed in that field: the Selex Saphira 320x256 [1] and the 320x255 RAPID detectors developed by Sofradir/CEA LETI in France [2], [3], [4]. Status of these two programs and future developments are presented. Sub-electron noise can now be achieved in the infrared using this technology. The exceptional characteristics of HgCdTe APDs are due to a nearly exclusive impaction ionization of the electrons, and this is why these devices have been called "electrons avalanche photodiodes" or e-APDs. These characteristics have inspired a large effort in developing focal plan arrays using HgCdTe APDs for low photon number applications such as active imaging in gated mode (2D) and/or with direct time of flight detection (3D imaging) and, more recently, passive imaging for infrared wave front correction and fringe tracking in astronomical observations. In addition, a commercial camera solution called C-RED, based on Selex Saphira and commercialized by First Light Imaging [5], is presented here. Some groups are also working with instruments in the visible. In that case, another disruptive technology is showing outstanding performances: the Electron Multiplying CCDs (EMCCD) developed mainly by e2v technologies in UK. The OCAM2 camera, commercialized by First Light Imaging [5], uses the 240x240 EMMCD from e2v and is successfully implemented on the VEGA instrument on the CHARA

  16. Self powered neutron detectors as in-core detectors for Sodium-cooled Fast Reactors

    Science.gov (United States)

    Verma, V.; Barbot, L.; Filliatre, P.; Hellesen, C.; Jammes, C.; Svärd, S. Jacobsson

    2017-07-01

    Neutron flux monitoring system forms an integral part of the design of a Generation IV sodium cooled fast reactor. Diverse possibilities of detector system installation must be studied for various locations in the reactor vessel in order to detect any perturbations in the core. Results from a previous paper indicated that it is possible to detect changes in neutron source distribution initiated by an inadvertent withdrawal of outer control rod with in-vessel fission chambers located azimuthally around the core. It is, however, not possible to follow inner control rod withdrawal and precisely know the location of the perturbation in the core. Hence the use of complimentary in-core detectors coupled with the peripheral fission chambers is proposed to enable robust core monitoring across the radial direction. In this paper, we assess the feasibility of using self-powered neutron detectors (SPNDs) as in-core detectors in fast reactors for detecting local changes in the power distribution when the reactor is operated at nominal power. We study the neutron and gamma contributions to the total output current of the detector modelled with Platinum as the emitter material. It is shown that this SPND placed in an SFR-like environment would give a sufficiently measurable prompt neutron induced current of the order of 600 nA/m. The corresponding induced current in the connecting cable is two orders of magnitude lower and can be neglected. This means that the SPND can follow in-core power fluctuations. This validates the operability of an SPND in an SFR-like environment.

  17. Fast digitizing and digital signal processing of detector signals

    International Nuclear Information System (INIS)

    Hannaske, Roland

    2008-01-01

    A fast-digitizer data acquisition system recently installed at the neutron time-of-flight experiment nELBE, which is located at the superconducting electron accelerator ELBE of Forschungszentrum Dresden-Rossendorf, is tested with two different detector types. Preamplifier signals from a high-purity germanium detector are digitized, stored and finally processed. For a precise determination of the energy of the detected radiation, the moving-window deconvolution algorithm is used to compensate the ballistic deficit and different shaping algorithms are applied. The energy resolution is determined in an experiment with γ-rays from a 22 Na source and is compared to the energy resolution achieved with analogously processed signals. On the other hand, signals from the photomultipliers of barium fluoride and plastic scintillation detectors are digitized. These signals have risetimes of a few nanoseconds only. The moment of interaction of the radiation with the detector is determined by methods of digital signal processing. Therefore, different timing algorithms are implemented and tested with data from an experiment at nELBE. The time resolutions achieved with these algorithms are compared to each other as well as to reference values coming from analog signal processing. In addition to these experiments, some properties of the digitizing hardware are measured and a program for the analysis of stored, digitized data is developed. The analysis of the signals shows that the energy resolution achieved with the 10-bit digitizer system used here is not competitive to a 14-bit peak-sensing ADC, although the ballistic deficit can be fully corrected. However, digital methods give better result in sub-ns timing than analog signal processing. (orig.)

  18. Successful beam tests for ALICE Transition Radiation Detector

    CERN Multimedia

    2002-01-01

    Another round of beam tests of prototypes for the Transition Radiation Detector (TRD) for ALICE has been completed and there are already some good results. Mass production of the components of the detector will start early next year.   Top view of the setup for the Transition Radiation Detector prototype tests at CERN.On the left, can be seen the full-scale TRD prototype together with four smaller versions. These are busy days for the TRD (Transition Radiation Detector) team of ALICE. Twenty people - mainly from Germany, but also from Russia and Japan - were working hard during the beam tests this autumn at CERN to assess the performance of their detector prototypes. Analysis of the data shows that the TRD can achieve the desired physics goal even for the highest conceivable multiplicities in lead-lead collisions at the LHC. In its final configuration in the ALICE experiment, the TRD will greatly help in identifying high-momentum electrons, which are 'needles in a haystack' that consists mostly of...

  19. A novel fast timing micropattern gaseous detector: FTM

    CERN Document Server

    De Oliveira, Rui; Sharma, Archana

    2015-01-01

    In recent years important progress in micropattern gaseous detectors has been achieved in the use of resistive material to build compact spark-protected devices. The novel idea presented here consists of the polarisation of WELL structures using only resistive coating. This allows a new device to be built with an architecture based on a stack of several coupled layers where drift and WELL multiplication stages alternate in the structure. The signals from each multiplication stage can be read out from any external readout boards through the capacitive couplings. Each layer provides a signal with a gain of 10^4-10^5. The main advantage of this new device is the dramatic improvement of the timing provided by the competition of the ionisation processes in the different drift regions, which can be exploited for fast timing at the high luminosity accelerators (e.g. HL-LHC upgrade) as well as far applications like medical imaging.

  20. A novel fast timing micropattern gaseous detector: FTM

    CERN Document Server

    De Oliveira, Rui; Maggi, Marcello

    2015-01-01

    In recent years important progress in micropattern gaseous detectors has been achieved in the use of resistive material to build compact spark-protected devices. The novel idea presented here consists of the polarisation of WELL structures using only resistive electrodes. This allows a new device to be built with an architecture based on a stack of several coupled layers where drift and WELL multiplication stages alternate in the structure. The signals from each multiplication stage can be read out from any external readout boards through the capacitive couplings. Each layer provides a signal with a gain of 10^4 - 10^5. The main advantage of this new device is the dramatic improvement of the timing provided by the competition of the ionisation processes in the different drift regions, which can be exploited for fast timing at the high luminosity accelerators (e.g. HL-LHC upgrade) as well as applications outside particle physics.

  1. Dose Calibration of the ISS-RAD Fast Neutron Detector

    Science.gov (United States)

    Zeitlin, C.

    2015-01-01

    The ISS-RAD instrument has been fabricated by Southwest Research Institute and delivered to NASA for flight to the ISS in late 2015 or early 2016. ISS-RAD is essentially two instruments that share a common interface to ISS. The two instruments are the Charged Particle Detector (CPD), which is very similar to the MSL-RAD detector on Mars, and the Fast Neutron Detector (FND), which is a boron-loaded plastic scintillator with readout optimized for the 0.5 to 10 MeV energy range. As the FND is completely new, it has been necessary to develop methodology to allow it to be used to measure the neutron dose and dose equivalent. This talk will focus on the methods developed and their implementation using calibration data obtained in quasi-monoenergetic (QMN) neutron fields at the PTB facility in Braunschweig, Germany. The QMN data allow us to determine an approximate response function, from which we estimate dose and dose equivalent contributions per detected neutron as a function of the pulse height. We refer to these as the "pSv per count" curves for dose equivalent and the "pGy per count" curves for dose. The FND is required to provide a dose equivalent measurement with an accuracy of ?10% of the known value in a calibrated AmBe field. Four variants of the analysis method were developed, corresponding to two different approximations of the pSv per count curve, and two different implementations, one for real-time analysis onboard ISS and one for ground analysis. We will show that the preferred method, when applied in either real-time or ground analysis, yields good accuracy for the AmBe field. We find that the real-time algorithm is more susceptible to chance-coincidence background than is the algorithm used in ground analysis, so that the best estimates will come from the latter.

  2. A transition radiation detector for positron identification in a balloon-borne particle astrophysics experiment

    International Nuclear Information System (INIS)

    Barbarito, E.; Bellotti, R.; Cafagna, F.; Castellano, M.; Circella, M.; De Cataldo, G.; De Marzo, C.; Fusco, P.; Giglietto, N.; Mongelli, M.; Marangelli, B.; Perchiazzi, M.; Raino, A.; Sacchetti, A.; Spinelli, P.

    1995-01-01

    We have built and tested a transition radiation detector of about 76x80 cm 2 active surface to discriminate positrons from protons in an experiment performed on a balloon flight to search for primordial antimatter. The TRD is made of ten modules each consisting of a carbon fiber radiator followed by a multiwire proportional chamber. In order to achieve a proton-electron rejection factor of the order of 10 -3 with a strict limitation on power consumption to about 40 mW per chamber channel, as required by experimental constraints, we have developed a low power consumption ''cluster counting'' electronics. Different analysis procedures of calibration data are shown. In addition, comparisons of the performances of this detector are also made with a previous similar prototype equipped with standard fast electronics and similar detectors from other authors. ((orig.))

  3. Integrated High-Rate Transition Radiation Detector and Tracking Chamber for the LHC

    CERN Multimedia

    2002-01-01

    % RD-6 \\\\ \\\\Over the past five years, RD-6 has developed a transition radiation detector and charged particle tracker for high rate operation at LHC. The detector elements are based on C-fibre reinforced kapton straw tubes of 4~mm diameter filled with a Xenon gas mixture. Detailed measurements with and without magnetic field have been performed in test beams, and in particular have demonstrated the possibility of operating straw tubes at very high rate (up to 20~MHz) with accurate drift-time measurement accuracy. A full-scale engineering prototype containing 10~000 straws is presently under assembly and will be accurately measured with a powerful X-ray tube. Integrated front-end electronics with fast readout have been designed and successfully operated in test beam. \\\\ \\\\Finally extensive simulations performed for ATLAS have shown that such a detector will provide powerful pattern recognition, accurate momentum measurements, efficient level-2 triggering and excellent electron identification, even at the highe...

  4. Glass transition of anhydrous starch by fast scanning calorimetry.

    Science.gov (United States)

    Monnier, Xavier; Maigret, Jean-Eudes; Lourdin, Denis; Saiter, Allisson

    2017-10-01

    By means of fast scanning calorimetry, the glass transition of anhydrous amorphous starch has been measured. With a scanning rate of 2000Ks -1 , thermal degradation of starch prior to the glass transition has been inhibited. To certify the glass transition measurement, structural relaxation of the glassy state has been investigated through physical aging as well as the concept of limiting fictive temperature. In both cases, characteristic enthalpy recovery peaks related to the structural relaxation of the glass have been observed. Thermal lag corrections based on the comparison of glass transition temperatures measured by means of differential and fast scanning calorimetry have been proposed. The complementary investigations give an anhydrous amorphous starch glass transition temperature of 312±7°C. This estimation correlates with previous extrapolation performed on hydrated starches. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Human skeletal muscle: transition between fast and slow fibre types.

    Science.gov (United States)

    Neunhäuserer, Daniel; Zebedin, Michaela; Obermoser, Magdalena; Moser, Gerhard; Tauber, Mark; Niebauer, Josef; Resch, Herbert; Galler, Stefan

    2011-05-01

    Human skeletal muscles consist of different fibre types: slow fibres (slow twitch or type I) containing the myosin heavy chain isoform (MHC)-I and fast fibres (fast twitch or type II) containing MHC-IIa (type IIA) or MHC-IId (type IID). The following order of decreasing kinetics is known: type IID > type IIA > type I. This order is especially based on the kinetics of stretch activation, which is the most discriminative property among fibre types. In this study we tested if hybrid fibres containing both MHC-IIa and MHC-I (type C fibres) provide a transition in kinetics between fast (type IIA) and slow fibres (type I). Our data of stretch activation kinetics suggest that type C fibres, with different ratios of MHC-IIa and MHC-I, do not provide a continuous transition. Instead, a specialized group of slow fibres, which we called "transition fibres", seems to provide a transition. Apart of their kinetics of stretch activation, which is most close to that of type IIA, the transition fibres are characterized by large cross-sectional areas and low maximal tensions. The molecular cause for the mechanical properties of the transition fibres is unknown. It is possible that the transition fibres contain an unknown slow MHC isoform, which cannot be separated by biochemical methods. Alternatively, or in addition, isoforms of myofibrillar proteins, other than MHC, and posttranslational modifications of myofibrillar proteins could play a role regarding the characteristics of the transition fibres.

  6. A New Transition Radiation Detector for the CREAM experiment

    CERN Document Server

    Malinin, A; Angelaszek, D

    The Cosmic Ray Energetics And Mass (CREAM) experiment is designed to investigate the source, propagation and acceleration mechanism of high energy cosmic-ray nuclei, by directly measuring their energy and charge. Incorporating a Transition Radiation Detector (TRD) provides a model independent energy measurement complementary to the calorimeter, as well as additional track reconstruction capability. A new TRD design provides a compact, robust, reliable, low density detector to measure incident nucleus energy for 3 < Z < 26 nuclei in the Lorentz gamma factor range of 10 2 -10 5. The TRD design, R&D;, construction milestones, beam test results and a progress of the final TRD integration in the CREAM instrument are reported.

  7. The ALICE Transition Radiation Detector: Construction, operation, and performance

    Science.gov (United States)

    Alice Collaboration

    2018-02-01

    The Transition Radiation Detector (TRD) was designed and built to enhance the capabilities of the ALICE detector at the Large Hadron Collider (LHC). While aimed at providing electron identification and triggering, the TRD also contributes significantly to the track reconstruction and calibration in the central barrel of ALICE. In this paper the design, construction, operation, and performance of this detector are discussed. A pion rejection factor of up to 410 is achieved at a momentum of 1 GeV/ c in p-Pb collisions and the resolution at high transverse momentum improves by about 40% when including the TRD information in track reconstruction. The triggering capability is demonstrated both for jet, light nuclei, and electron selection.

  8. Fast parallel ring recognition algorithm in the RICH detector of the CBM experiment at FAIR

    International Nuclear Information System (INIS)

    Lebedev, S.

    2011-01-01

    The Compressed Baryonic Matter (CBM)experiment at the future FAIR facility at Darmstadt will measure dileptons emitted from the hot and dense phase in heavy ion collisions. In case of an electron measurement, a high purity of identified electrons is required in order to suppress the background. Electron identification in CBM will be performed by a Ring Imaging Cherenkov (RICH) detector and Transition Radiation Detector (TRD). Very fast data reconstruction is extremely important for CBM because of the huge amount of data which has to be handled. In this contribution, a parallelized ring recognition algorithm is presented. Modern CPUs have two features, which enable parallel programming. First, the SSE technology allows using the SIMD execution model. Second, multicore CPUs enable the use of multithreading. Both features have been implemented in the ring reconstruction of the RICH detector. A considerable speedup factor from 357 to 2.5 ms/event has been achieved including preceding code optimization for Intel Xeon X5550 processors at 2.67 GHz

  9. Fast simulation of the forward tracking detector of HPLUS

    International Nuclear Information System (INIS)

    Zhang Yapeng; Fan Ruirui; Fu Fen; Yue Ke; Yuan Xiaohua; Xu Huagen; Chinese Academy of Sciences, Beijing; Yao Nan; Xu Hushan; Jin Genming; Liang Jinjie; Chen Ruofu; Sun Zhiyu; Duan Limin; Xiao Zhigang; Tsinghua Univ., Beijing

    2008-01-01

    The necessity of installing a forward tracking detector stack is discussed for the Hadron Physics Lanzhou Spectrometer(HPLUS). A local tracker is developed to solve the multi-track finding problem. The track candidates are searched iteratively via Hough Transform. The fake tracks are removed by a least square fitting process. With this tracker we have studied the feasibility of pp→pp+φ(→K + K - ), a typical physical channel proposed on HPLUS. The single track momentum resolution due to the uncertainty of the positioning in FTD is 1.3%. The multiple scattering effect contributes about 20% to the momentum resolution in the FTD coverage. The width and the signal-to-background ratio of the reconstructed φ are 1.51 MeV and 4.36, respectively, taking into account the direct Kaon channel pp→pp+K + K - as background. The geometry coverage of FTD for qb events is about 85.4%. Based on the current fast simulation and estimation, the geometrical configuration of FTD meets the physical requirement of HPLUS under the current luminosity and multiplicity conditions. The tracker is applicable in the full simulation coming next and is extendable to other tracking component of HPLUS. (authors)

  10. Fast change in core transport after L-H transition

    International Nuclear Information System (INIS)

    Kadomtsev, B.B.; Itoh, K.; Itoh, S.

    1995-03-01

    The transport in the core tokamak plasma is known to change very rapidly after the L-H transition in the edge plasma. A qualitative discussion is given for this fast transmission of the transport change. A picture based on the successive bifurcations is presented. (author)

  11. Improvement of radiation response characteristic on CdTe detectors using fast neutron irradiation

    International Nuclear Information System (INIS)

    Miyamaru, Hiroyuki; Takahashi, Akito; Iida, Toshiyuki

    1999-01-01

    The treatment of fast neutron pre-irradiation was applied to a CdTe radiation detector in order to improve radiation response characteristic. Electron transport property of the detector was changed by the irradiation effect to suppress pulse amplitude fluctuation in risetime. Spectroscopic performance of the pre-irradiated detector was compared with the original. Additionally, the pre-irradiated detector was employed with a detection system using electrical signal processing of risetime discrimination (RTD). Pulse height spectra of 241 Am, 133 Ba, and 137 Cs gamma rays were measured to examine the change of the detector performance. The experimental results indicated that response characteristic for high-energy photons was improved by the pre-irradiation. The combination of the pre-irradiated detector and the RTD processing was found to provide further enhancement of the energy resolution. Application of fast neutron irradiation effect to the CdTe detector was demonstrated. (author)

  12. Fast neutron dosimetry by means of different solid state nuclear track detectors

    International Nuclear Information System (INIS)

    Spurny, F.; Turek, K.

    1977-01-01

    The comparative study of three different types of fast neutron dosimeters based on solid state nuclear track detectors is presented; the dosimeters studied were: - microscopic soda glass in contact with 232 Th; - polycarbonate Makrofol E; and - cellulose nitrate Kodak LR 115. All detectors were evaluated by visual counting in a microscope. The authors have studied such properties as the background, angular as well as energetical dependences of detectors. The results obtained show that all studied detectors are suitable for fast neutron dosimetry; their application depends however on the concrete experimental conditions (neutron spectrum, fluence etc.). Both advantages and disadvantages of each of them are presented. (Auth.)

  13. fastBMA: scalable network inference and transitive reduction.

    Science.gov (United States)

    Hung, Ling-Hong; Shi, Kaiyuan; Wu, Migao; Young, William Chad; Raftery, Adrian E; Yeung, Ka Yee

    2017-10-01

    Inferring genetic networks from genome-wide expression data is extremely demanding computationally. We have developed fastBMA, a distributed, parallel, and scalable implementation of Bayesian model averaging (BMA) for this purpose. fastBMA also includes a computationally efficient module for eliminating redundant indirect edges in the network by mapping the transitive reduction to an easily solved shortest-path problem. We evaluated the performance of fastBMA on synthetic data and experimental genome-wide time series yeast and human datasets. When using a single CPU core, fastBMA is up to 100 times faster than the next fastest method, LASSO, with increased accuracy. It is a memory-efficient, parallel, and distributed application that scales to human genome-wide expression data. A 10 000-gene regulation network can be obtained in a matter of hours using a 32-core cloud cluster (2 nodes of 16 cores). fastBMA is a significant improvement over its predecessor ScanBMA. It is more accurate and orders of magnitude faster than other fast network inference methods such as the 1 based on LASSO. The improved scalability allows it to calculate networks from genome scale data in a reasonable time frame. The transitive reduction method can improve accuracy in denser networks. fastBMA is available as code (M.I.T. license) from GitHub (https://github.com/lhhunghimself/fastBMA), as part of the updated networkBMA Bioconductor package (https://www.bioconductor.org/packages/release/bioc/html/networkBMA.html) and as ready-to-deploy Docker images (https://hub.docker.com/r/biodepot/fastbma/). © The Authors 2017. Published by Oxford University Press.

  14. The transition radiation detector of the PAMELA space mission

    Science.gov (United States)

    Ambriola, M.; Bellotti, R.; Cafagna, F.; Circella, M.; de Marzo, C.; Giglietto, N.; Marangelli, B.; Mirizzi, N.; Romita, M.; Spinelli, P.

    2004-04-01

    PAMELA space mission objective is to flight a satellite-borne magnetic spectrometer built to fulfill the primary scientific goals of detecting antiparticles (antiprotons and positrons) and to measure spectra of particles in cosmic rays. The PAMELA telescope is composed of: a silicon tracker housed in a permanent magnet, a time-of-flight and an anticoincidence system both made of plastic scintillators, a silicon imaging calorimeter, a neutron detector and a Transition Radiation Detector (TRD). The TRD is composed of nine sensitive layers of straw tubes working in proportional mode for a total of 1024 channels. Each layer is interleaved with a radiator plane made of carbon fibers. The TRD characteristics will be described along with its performances studied at both CERN-PS and CERN-SPS facilities, using electrons, pions, muons and protons of different momenta.

  15. The transition radiation detector of the PAMELA space mission

    International Nuclear Information System (INIS)

    Ambriola, M.; Bellotti, R.; Cafagna, F.; Circella, M.; De Marzo, C.; Giglietto, N.; Marangelli, B.; Mirizzi, N.; Romita, M.; Spinelli, P.

    2004-01-01

    PAMELA space mission objective is to flight a satellite-borne magnetic spectrometer built to fulfill the primary scientific goals of detecting antiparticles (antiprotons and positrons) and to measure spectra of particles in cosmic rays. The PAMELA telescope is composed of: a silicon tracker housed in a permanent magnet, a time-of-flight and an anticoincidence system both made of plastic scintillators, a silicon imaging calorimeter, a neutron detector and a Transition Radiation Detector (TRD). The TRD is composed of nine sensitive layers of straw tubes working in proportional mode for a total of 1024 channels. Each layer is interleaved with a radiator plane made of carbon fibers. The TRD characteristics will be described along with its performances studied at both CERN-PS and CERN-SPS facilities, using electrons, pions, muons and protons of different momenta

  16. Progress in the development of a tracking transition radiation detector

    International Nuclear Information System (INIS)

    Whitaker, J.S.; Beatty, J.; Shank, J.T.; Wilson, R.J.; Polychronakos, V.A.; Radeka, V.; Stephani, D.; Beker, H.; Bock, R.K.; Botlo, M.; Fabjan, C.W.; Pfennig, J.; Price, M.J.; Willis, W.J.; Akesson, T.; Chernyatin, V.; Dolgoshein, B.; Nevsky, P.; Potekhin, M.; Romanjuk, A.; Sosnovtsev, V.; Gavrilenko, I.; Maiburov, S.; Muravjev, S.; Shmeleva, A.

    1990-01-01

    The purpose of the TRD/Tracker is to provide charged particle tracking in the r-z plane and to provide particle identification capabilities that are independent of and complementary to calorimetric methods. The tracking goals include observation of the charged particle multiplicity and topology, reconstruction of the primary vertex or vertices, and assignment of charged particles to the correct vertex. Particle identification goals include the independent validation of electron candidates selected by calorimetric signatures, the rejection of false electron candidates that rise from accidental overlaps of low momentum charged particles with photon-induced electromagnetic showers in the calorimeter, and the identification of electrons arising from Dalitz decays or from photon conversions. The authors report on progress towards the development of an integrated transition radiation detector and charged particle tracker. Mechanical design and simulation of a detector has been pursued; a prototype device with 240 channels has been constructed and tested. Innovative construction techniques have been developed

  17. Fast SiPM Readout of the PANDA TOF Detector

    International Nuclear Information System (INIS)

    Böhm, M.; Lehmann, A.; Motz, S.; Uhlig, F.

    2016-01-01

    For the identification of low momentum charged particles and for event timing purposes a barrel Time-of-Flight (TOF) detector surrounding the interaction point is planned for the PANDA experiment at FAIR . Since the boundary conditions in terms of available radial space and radiation length are quite strict the favored layout is a hodoscope composed of several thousand small scintillating tiles (SciTils) read out by silicon photomultipliers (SiPMs). A time resolution of well below 100 ps is aimed for. With the originally proposed 30 × 30 × 5 mm 3 SciTils read out by two single 3 × 3 mm 2 SiPMs at the rims of the scintillator the targeted time resolution can be just reached, but with a considerable position dependence across the scintillator surface. In this paper we discuss other design options to further improve the time resolution and its homogeneity. It will be shown that wide scintillating rods (SciRods) with a size of, e.g., 50 × 30 × 5 mm 3 or longer and read out at opposite sides by a chain of four serially connected SiPMs a time resolution down to 50 ps can be reached without problems. In addition, the position dependence of the time resolution is negligible. These SciRods were tested in the laboratory with electrons of a 90 Sr source and under real experimental conditions in a particle beam at CERN. The measured time resolutions using fast BC418 or BC420 plastic scintillators wrapped in aluminum foil were consistently between 45 and 75 ps dependent on the SciRod design. This is a significant improvement compared to the original SciTil layout.

  18. The ALICE Transition Radiation Detector: Construction, operation, and performance

    Czech Academy of Sciences Publication Activity Database

    Acharya, S.; Adamová, Dagmar; Bielčík, J.; Bielčíková, Jana; Brož, M.; Contreras, J. G.; Ferencei, Jozef; Hladký, Jan; Horák, D.; Křížek, Filip; Kučera, Vít; Kushpil, Svetlana; Lavička, R.; Mareš, Jiří A.; Petráček, V.; Šumbera, Michal; Vaňát, Tomáš; Závada, Petr

    2018-01-01

    Roč. 881, č. 2 (2018), s. 88-127 ISSN 0168-9002 R&D Projects: GA MŠk(CZ) LG15052 Institutional support: RVO:68378271 ; RVO:61389005 Keywords : fibre/foam sendwich radiator * transition radiation detector * multi-wire proportional drift chamber * Xenon-based gas micture * tracking * lonisation energy loss Subject RIV: BG - Nuclear, Atomic and Molecular Physics , Colliders; BF - Elementary Particles and High Energy Physics (FZU-D) OBOR OECD: Nuclear physics ; Particles and field physics (FZU-D) Impact factor: 1.362, year: 2016

  19. Performance of the AMS-02 Transition Radiation Detector

    CERN Document Server

    von Doetinchem, P.; Karpinski, W.; Kirn, T.; Luebelsmeyer, K.; Orboeck, J.; Schael, S.; Schultz von Dratzig, A.; Schwering, G.; Siedenburg, T.; Siedling, R.; Wallraff, W.; Becker, U.; Burger, J.; Henning, R.; Kounine, A.; Koutsenko, V.; Wyatt, J.

    2006-01-01

    For cosmic particle spectroscopy on the International Space Station the AMS experiment will be equipped with a Transition Radiation Detector (TRD) to improve particle identification. The TRD has 20 layers of fleece radiator with Xe/CO2 proportional mode straw tube chambers. They are supported in a conically shaped octagon structure made of CFC-Al-honeycomb. For low power consumption VA analog multiplexers are used as front-end readout. A 20 layer prototype built from final design components has achieved proton rejections from 100 to 2000 at 90% electron efficiency for proton beam energies up to 250 GeV with cluster counting, likelihood and neural net selection algorithms.

  20. Fast electric dipole transitions in Ra-Ac nuclei

    International Nuclear Information System (INIS)

    Ahmad, I.

    1985-01-01

    Lifetime of levels in 225 Ra, 225 Ac, and 227 Ac have been measured by delayed coincidence techniques and these have been used to determine the E1 gamma-ray transition probabilities. The reduced E1 transition probabilities. The reduced E1 transition probabilities in 225 Ra and 225 Ac are about two orders of magnitude larger than the values in mid-actinide nuclei. On the other hand, the E1 rate in 227 Ac is similar to those measured in heavier actinides. Previous studies suggest the presence of octupole deformation in all the three nuclei. The present investigation indicates that fast E1 transitions occur for nuclei with octupole deformation. However, the studies also show that there is no one-to-one correspondence between E1 rate and octupole deformation. 13 refs., 4 figs

  1. Near midplane scintillator-based fast ion loss detector on DIII-D.

    Science.gov (United States)

    Chen, X; Fisher, R K; Pace, D C; García-Muñoz, M; Chavez, J A; Heidbrink, W W; Van Zeeland, M A

    2012-10-01

    A new scintillator-based fast-ion loss detector (FILD) installed near the outer midplane of the plasma has been commissioned on DIII-D. This detector successfully measures coherent fast ion losses produced by fast-ion driven instabilities (≤500 kHz). Combined with the first FILD at ∼45° below the outer midplane [R. K. Fisher, et al., Rev. Sci. Instrum. 81, 10D307 (2010)], the two-detector system measures poloidal variation of losses. The phase space sensitivity of the new detector (gyroradius r(L) ∼ [1.5-8] cm and pitch angle α ∼ [35°-85°]) is calibrated using neutral beam first orbit loss measurements. Since fast ion losses are localized poloidally, having two FILDs at different poloidal locations allows for the study of losses over a wider range of plasma shapes and types of loss orbits.

  2. Fast current amplifier for background-limited operation of photovoltaic InSb detectors

    Energy Technology Data Exchange (ETDEWEB)

    Altmann, J; Koehler, S; Lahmann, W

    1981-01-01

    A fast current amplifier for use with photovoltaic indium antimonide detectors is described which was designed for detection of lidar return signals. Near background-limited operation was possible for bandwidths up to 0.8 MHz.

  3. Triple GEM gas detectors as real time fast neutron beam monitors for spallation neutron sources

    International Nuclear Information System (INIS)

    Murtas, F; Claps, G; Croci, G; Tardocchi, M; Pietropaolo, A; Cippo, E Perelli; Rebai, M; Gorini, G; Frost, C D; Raspino, D; Rhodes, N J; Schooneveld, E M

    2012-01-01

    A fast neutron beam monitor based on a triple Gas Electron Multiplier (GEM) detector was developed and tested for the ISIS spallation neutron source in U.K. The test on beam was performed at the VESUVIO beam line operating at ISIS. The 2D fast neutron beam footprint was recorded in real time with a spatial resolution of a few millimeters thanks to the patterned detector readout.

  4. Calibration and Simulation of the GRB trigger detector of the Ultra Fast Flash Observatory

    DEFF Research Database (Denmark)

    Huang, M.-H.A.; Ahmad, S.; Barrillon, P.

    2013-01-01

    The UFFO (Ultra-Fast Flash Observatory) is a GRB detector on board the Lomonosov satellite, to be launched in 2013. The GRB trigger is provided by an X-ray detector, called UBAT (UFFO Burst Alarm & Trigger Telescope), which detects X-rays from the GRB and then triggers to determine the direction ...

  5. Fast detector for triggering on charged particle multiplicity for relativistic nucleus-nucleus collisions

    International Nuclear Information System (INIS)

    Agakishiev, G.; Man'yakov, P.K.; Drees, A.

    1997-01-01

    The simple and fast detector of charged particle multiplicity for relativistic nucleus-nucleus collision studies is performed. The multiplicity detector has been designed for the first level trigger of the CERES/NA45 experiment to study Pb-Au collisions at CERN SPS energies. The detector has allowed a realization of the 40 ns trigger for selection of events with definite impact parameter. The construction, operation characteristics, method of calibration, and testing results are described in detail

  6. HEROICA: A fast screening facility for the characterization of germanium detectors

    Energy Technology Data Exchange (ETDEWEB)

    Andreotti, Erica [Universität Tübingen, Auf der Morgenstelle 14, 72076 Tübingen (Germany); Collaboration: GERDA Collaboration

    2013-08-08

    In the course of 2012, a facility for the fast screening of germanium detectors called HEROICA (Hades Experimental Research Of Intrinsic Crystal Appliances) has been installed at the HADES underground laboratory in the premises of the Belgian Nuclear Research Centre SCK•CEN, in Mol (Belgium). The facility allows performing a complete characterization of the critical germanium detectors' operational parameters with a rate of about two detectors per week.

  7. 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.

  8. Fast cryogenic detectors for neutrinos and dark matter

    International Nuclear Information System (INIS)

    Gonzalez-Mestres, L.

    1990-01-01

    We briefly review some recent developments on cryogenic detectors whose response is not entirely limited in speed by heat or phonon propagation through a macroscopic medium. Two subjects are dealt with: a) the use of superheated superconducting granules (SSG) for nucleus recoil detection (dedicated to low energy neutrinos and WIMP dark matter); b) a possible new generation of devices eventually able to perform particle identification (therefore improving background rejection), through simultaneous measurement of ionization and heat: luminescent bolometer, calorimetric ionization detector

  9. Development of a fast multi-line x-ray CT detector for NDT

    International Nuclear Information System (INIS)

    Hofmann, T.; Nachtrab, F.; Schlechter, T.; Mühlbauer, J.; Schröpfer, S.; Firsching, M.; Uhlmann, N.; Neubauer, H.; Ernst, J.; Schweiger, T.; Oberst, M.; Meyer, A.

    2015-01-01

    Typical X-ray detectors for non-destructive testing (NDT) are line detectors or area detectors, like e.g. flat panel detectors. Multi-line detectors are currently only available in medical Computed Tomography (CT) scanners. Compared to flat panel detectors, line and multi-line detectors can achieve much higher frame rates. This allows time-resolved 3D CT scans of an object under investigation. Also, an improved image quality can be achieved due to reduced scattered radiation from object and detector themselves. Another benefit of line and multi-line detectors is that very wide detectors can be assembled easily, while flat panel detectors are usually limited to an imaging field with a size of approx. 40 × 40 cm 2 at maximum. The big disadvantage of line detectors is the limited number of object slices that can be scanned simultaneously. This leads to long scan times for large objects. Volume scans with a multi-line detector are much faster, but with almost similar image quality. Due to the promising properties of multi-line detectors their application outside of medical CT would also be very interesting for NDT. However, medical CT multi-line detectors are optimized for the scanning of human bodies. Many non-medical applications require higher spatial resolutions and/or higher X-ray energies. For those non-medical applications we are developing a fast multi-line X-ray detector.In the scope of this work, we present the current state of the development of the novel detector, which includes several outstanding properties like an adjustable curved design for variable focus-detector-distances, conserving nearly uniform perpendicular irradiation over the entire detector width. Basis of the detector is a specifically designed, radiation hard CMOS imaging sensor with a pixel pitch of 200 μ m. Each pixel has an automatic in-pixel gain adjustment, which allows for both: a very high sensitivity and a wide dynamic range. The final detector is planned to have 256 lines of

  10. High-speed, multi-channel detector readout electronics for fast radiation detectors

    International Nuclear Information System (INIS)

    Hennig, Wolfgang

    2012-01-01

    In this project, we are developing a high speed digital spectrometer that a) captures detector waveforms at rates up to 500 MSPS b) has upgraded event data acquisition with additional data buffers for zero dead time operation c) moves energy calculations to the FPGA to increase spectrometer throughput in fast scintillator applications d) uses a streamlined architecture and high speed data interface for even faster readout to the host PC These features are in addition to the standard functions in our existing spectrometers such as digitization, programmable trigger and energy filters, pileup inspection, data acquisition with energy and time stamps, MCA histograms, and run statistics. In Phase I, we upgraded one of our existing spectrometer designs to demonstrate the key principle of fast waveform capture using a 500 MSPS, 12 bit ADC and a Xilinx Virtex-4 FPGA. This upgraded spectrometer, named P500, performed well in initial tests of energy resolution, pulse shape analysis, and timing measurements, thus achieving item (a) above. In Phase II, we are revising the P500 to build a commercial prototype with the improvements listed in items (b)-(d). As described in the previous report, two devices were built to pursue this goal, named the Pixie-500 and the Pixie-500 Express. The Pixie-500 has only minor improvements from the Phase I prototype and is intended as an early commercial product (its production and part of its development were funded outside the SBIR). It also allows testing of the ADC performance in real applications. The Pixie-500 Express (or Pixie-500e) includes all of the improvements (b)-(d). At the end of Phase II of the project, we have tested and debugged the hardware, firmware and software of the Pixie-500 Express prototype boards delivered 12/3/2010. This proved substantially more complex than anticipated. At the time of writing, all hardware bugs have been fixed, the PCI Express interface is working, the SDRAM has been successfully tested and the

  11. High-speed, multi-channel detector readout electronics for fast radiation detectors

    Energy Technology Data Exchange (ETDEWEB)

    Hennig, Wolfgang

    2012-06-22

    In this project, we are developing a high speed digital spectrometer that a) captures detector waveforms at rates up to 500 MSPS b) has upgraded event data acquisition with additional data buffers for zero dead time operation c) moves energy calculations to the FPGA to increase spectrometer throughput in fast scintillator applications d) uses a streamlined architecture and high speed data interface for even faster readout to the host PC These features are in addition to the standard functions in our existing spectrometers such as digitization, programmable trigger and energy filters, pileup inspection, data acquisition with energy and time stamps, MCA histograms, and run statistics. In Phase I, we upgraded one of our existing spectrometer designs to demonstrate the key principle of fast waveform capture using a 500 MSPS, 12 bit ADC and a Xilinx Virtex-4 FPGA. This upgraded spectrometer, named P500, performed well in initial tests of energy resolution, pulse shape analysis, and timing measurements, thus achieving item (a) above. In Phase II, we are revising the P500 to build a commercial prototype with the improvements listed in items (b)-(d). As described in the previous report, two devices were built to pursue this goal, named the Pixie-500 and the Pixie-500 Express. The Pixie-500 has only minor improvements from the Phase I prototype and is intended as an early commercial product (its production and part of its development were funded outside the SBIR). It also allows testing of the ADC performance in real applications.The Pixie-500 Express (or Pixie-500e) includes all of the improvements (b)-(d). At the end of Phase II of the project, we have tested and debugged the hardware, firmware and software of the Pixie-500 Express prototype boards delivered 12/3/2010. This proved substantially more complex than anticipated. At the time of writing, all hardware bugs have been fixed, the PCI Express interface is working, the SDRAM has been successfully tested and the SHARC

  12. Transitioning nuclear fuel cycles with uncertain fast reactor costs

    Energy Technology Data Exchange (ETDEWEB)

    Phathanapirom, U.B., E-mail: bphathanapirom@utexas.edu; Schneider, E.A.

    2016-06-15

    This paper applies a novel decision making methodology to a case study involving choices leading to the transition from the current once-through light water reactor fuel cycle to one relying on continuous recycle of plutonium and minor actinides in fast reactors in the face of uncertain fast reactor capital costs. Unique to this work is a multi-stage treatment of a range of plausible trajectories for the evolution of fast reactor capital costs over time, characterized by first-of-a-kind penalties as well as time- and unit-based learning. The methodology explicitly incorporates uncertainties in key parameters into the decision-making process by constructing a stochastic model and embedding uncertainties as bifurcations in the decision tree. “Hedging” strategies are found by applying a choice criterion to select courses of action which mitigate “regrets”. These regrets are calculated by evaluating the performance of all possible transition strategies for every feasible outcome of the uncertain parameter. The hedging strategies are those that preserve the most flexibility for adjusting the fuel cycle strategy in response to new information as uncertainties are resolved.

  13. Transitioning nuclear fuel cycles with uncertain fast reactor costs

    International Nuclear Information System (INIS)

    Phathanapirom, U.B.; Schneider, E.A.

    2016-01-01

    This paper applies a novel decision making methodology to a case study involving choices leading to the transition from the current once-through light water reactor fuel cycle to one relying on continuous recycle of plutonium and minor actinides in fast reactors in the face of uncertain fast reactor capital costs. Unique to this work is a multi-stage treatment of a range of plausible trajectories for the evolution of fast reactor capital costs over time, characterized by first-of-a-kind penalties as well as time- and unit-based learning. The methodology explicitly incorporates uncertainties in key parameters into the decision-making process by constructing a stochastic model and embedding uncertainties as bifurcations in the decision tree. “Hedging” strategies are found by applying a choice criterion to select courses of action which mitigate “regrets”. These regrets are calculated by evaluating the performance of all possible transition strategies for every feasible outcome of the uncertain parameter. The hedging strategies are those that preserve the most flexibility for adjusting the fuel cycle strategy in response to new information as uncertainties are resolved.

  14. Process guiding for the ZEUS transition-radiation detector

    International Nuclear Information System (INIS)

    Kowalksy, L.

    1993-03-01

    The Transition-Radiation-Detector (TRD) has been built to separate electrons from pions. It needs a complex gassystem which has to be controlled and monitored by a computer. To enable a test of the gassystem and the TRD's highvoltagesystem a stand-alone-version of the HWC/HWM (hardware-control and hardware-monitoring) had been developed. This stand-alone-version consists of an elementary computer- and software-system. VIP and MVME-147 computers have been selected for the computer-hardware. The computers for realtimeprocessing base on this processors, the VMEbus and digital to analog converters and analog to digital converters. The software-system based on OS/9 device-drivers. With this components monitoring and controlling software has been written. (orig.) [de

  15. Construction and performance of the ALICE Transition Radiation Detector

    Energy Technology Data Exchange (ETDEWEB)

    Emschermann, David

    2010-01-20

    The Transition Radiation Detector (TRD) has been designed to identify electrons in the pion dominated background of heavy-ions collisions. As electrons do not interact strongly, they allow to probe the early phase of the interaction. As trigger on high-p{sub t} e{sup +}e{sup -} pairs within 6.5 {mu}s after collision, the TRD can initiate the readout of the Time Projection Chamber (TPC). The TRD is composed of 18 super modules arranged in a barrel geometry in the central part of the ALICE detector. It offers almost 1.2 million readout channels on a total area of close to 700 m{sup 2}. The particle detection properties of the TRD depend crucially on details in the design of the cathode pad readout plane. The design parameters of the TRD readout pad plane are introduced and analysed regarding their physical properties. The noise patterns observed in the detector can be directly linked to the static pad capacitance distribution and corrected for it. A summary is then given of the TRD services infrastructure at CERN: a 70 kW low voltage system, a 1080 channel 2.5 kV high voltage setup and the Ethernet network serving more than 600 nodes. Two beam tests were conducted at the CERN PS accelerator in 2004 and 2007 using full sized TRD chambers from series production. Details on the setups are presented with particular emphasis on the custom tailored data acquisition systems. Finally the performance of the TRD is studied, focusing on the pion rejection capability and the excellent position resolution. (orig.)

  16. Construction and performance of the ALICE Transition Radiation Detector

    International Nuclear Information System (INIS)

    Emschermann, David

    2010-01-01

    The Transition Radiation Detector (TRD) has been designed to identify electrons in the pion dominated background of heavy-ions collisions. As electrons do not interact strongly, they allow to probe the early phase of the interaction. As trigger on high-p t e + e - pairs within 6.5 μs after collision, the TRD can initiate the readout of the Time Projection Chamber (TPC). The TRD is composed of 18 super modules arranged in a barrel geometry in the central part of the ALICE detector. It offers almost 1.2 million readout channels on a total area of close to 700 m 2 . The particle detection properties of the TRD depend crucially on details in the design of the cathode pad readout plane. The design parameters of the TRD readout pad plane are introduced and analysed regarding their physical properties. The noise patterns observed in the detector can be directly linked to the static pad capacitance distribution and corrected for it. A summary is then given of the TRD services infrastructure at CERN: a 70 kW low voltage system, a 1080 channel 2.5 kV high voltage setup and the Ethernet network serving more than 600 nodes. Two beam tests were conducted at the CERN PS accelerator in 2004 and 2007 using full sized TRD chambers from series production. Details on the setups are presented with particular emphasis on the custom tailored data acquisition systems. Finally the performance of the TRD is studied, focusing on the pion rejection capability and the excellent position resolution. (orig.)

  17. Fast neutron spectra determination by threshold activation detectors using neural networks

    International Nuclear Information System (INIS)

    Kardan, M.R.; Koohi-Fayegh, R.; Setayeshi, S.; Ghiassi-Nejad, M.

    2004-01-01

    Neural network method was used for fast neutron spectra unfolding in spectrometry by threshold activation detectors. The input layer of the neural networks consisted of 11 neurons for the specific activities of neutron-induced nuclear reaction products, while the output layers were fast neutron spectra which had been subdivided into 6, 8, 10, 12, 15 and 20 energy bins. Neural network training was performed by 437 fast neutron spectra and corresponding threshold activation detector readings. The trained neural network have been applied for unfolding 50 spectra, which were not in training sets and the results were compared with real spectra and unfolded spectra by SANDII. The best results belong to 10 energy bin spectra. The neural network was also trained by detector readings with 5% uncertainty and the response of the trained neural network to detector readings with 5%, 10%, 15%, 20%, 25% and 50% uncertainty was compared with real spectra. Neural network algorithm, in comparison with other unfolding methods, is very fast and needless to detector response matrix and any prior information about spectra and also the outputs have low sensitivity to uncertainty in the activity measurements. The results show that the neural network algorithm is useful when a fast response is required with reasonable accuracy

  18. Energy deposition measurements in fast reactor safety experiments with fission thermocouple detectors

    International Nuclear Information System (INIS)

    Wright, S.A.; Scott, H.L.

    1979-01-01

    The investigation of phenomena occurring in in-pile fast reactor safety experiments requires an accurate measurement of the time dependent energy depositions within the fissile material. At Sandia Laboratories thin-film fission thermocouples are being developed for this purpose. These detectors have high temperature capabilities (400 to 500 0 C), are sodium compatible, and have milli-second time response. A significant advantage of these detectors for use as energy deposition monitors is that they produce an output voltage which is directly dependent on the temperature of a small chip of fissile material within the detectors. However, heat losses within the detector make it necessary to correct the response of the detector to determine the energy deposition. A method of correcting the detector response which uses an inverse convolution procedure has been developed and successfully tested with experimental data obtained in the Sandia Pulse Reactor (SPR-II) and in the Annular Core Research Reactor

  19. Transition region, coronal heating and the fast solar wind

    Science.gov (United States)

    Li, Xing

    2003-07-01

    It is assumed that magnetic flux tubes are strongly concentrated at the boundaries of supergranule convection cells. A power law spectrum of high frequency Alfvén waves with a spectral index -1 originating from the sun is assumed to supply all the energy needed to energize the plasma flowing in such magnetic flux tubes. At the high frequency end, the waves are eroded by ions due to ion cyclotron resonance. The magnetic flux concentration is essential since it allows a sufficiently strong energy flux to be carried by high frequency ion cyclotron waves and these waves can be readily released at the coronal base by cyclotron resonance. The main results are: 1. The waves are capable of creating a steep transition region, a hot corona and a fast solar wind if both the wave frequency is high enough and the magnetic flux concentration is sufficiently strong in the boundaries of the supergranule convection zone. 2. By primarily heating alpha particles only, it is possible to produce a steep transition region, a hot corona and a fast solar wind. Coulomb coupling plays a key role in transferring the thermal energy of alpha particles to protons and electrons at the corona base. The electron thermal conduction then does the remaining job to create a sharp transition region. 3. Plasma species (even ions) may already partially lose thermal equilibrium in the transition region, and minor ions may already be faster than protons at the very base of the corona. 4. The model predicts high temperature alpha particles (Talpha ~ 2 x 107 K) and low proton temperatures (Tp solar radii, suggesting that hydrogen Lyman lines observed by UVCS above coronal holes may be primarily broadened by Alfvén waves in this range.

  20. Fast photon detection for the COMPASS RICH detector

    CERN Document Server

    Abbon, P; Alekseev, M; Angerer, H; Apollonio, M; Birsa, R; Bordalo, P; Bradamante, Franco; Bressan, A; Busso, L; Chiosso, M; Ciliberti, P; Colantoni, M L; Costa, S; Dalla Torre, S; Dafni, T; Delagnes, E; Deschamps, H; Díaz, V; Dibiase, N; Duic, V; Eyrich, W; Faso, D; Ferrero, A; Finger, M; Finger, M Jr; Fischer, H; Gerassimov, S; Giorgi, M; Gobbo, B; Hagemann, R; Von Harrach, D; Heinsius, F H; Joosten, R; Ketzer, B; Königsmann, K C; Kolosov, V N; Konorov, I; Kramer, Daniel; Kunne, Fabienne; Lehmann, A; Levorato, S; Maggiora, A; Magnon, A; Mann, A; Martin, A; Menon, G; Mutter, A; Nahle, O; Nerling, F; Neyret, D; Pagano, P; Panebianco, S; Panzieri, D; Paul, S; Pesaro, G; Polak, J; Rebourgeard, P; Robinet, F; Rocco, E; Schiavon, Paolo; Schroder, W; Silva, L; Slunecka, M; Sozzi, F; Steiger, L; Sulc, M; Svec, M; Tessarotto, F; Teufel, A; Wollny, H

    2007-01-01

    The COMPASS experiment at the SPS accelerator at CERN uses a large scale Ring Imaging CHerenkov detector (RICH) to identify pions, kaons and protons in a wide momentum range. For the data taking in 2006, the COMPASS RICH has been upgraded in the central photon detection area (25% of the surface) with a new technology to detect Cherenkov photons at very high count rates of several 10^6 per second and channel and a new dead-time free read-out system, which allows trigger rates up to 100 kHz. The Cherenkov photons are detected by an array of 576 visible and ultra-violet sensitive multi-anode photomultipliers with 16 channels each. The upgraded detector showed an excellent performance during the 2006 data taking.

  1. Developing a fast simulator for irradiated silicon detectors

    CERN Document Server

    Diez Gonzalez-Pardo, Alvaro

    2015-01-01

    Simulation software for irradiated silicon detectors has been developed on the basis of an already existing C++ simulation software called TRACS[1]. This software has been already proven useful in understanding non-irradiated silicon diodes and microstrips. In addition a wide variety of user-focus features has been implemented to improve on TRACS flexibility. Such features include an interface to allow any program to leverage TRACS functionalities, a configuration file and improved documentation.

  2. Fast Neutron Dosimetry Using CR-39 Nuclear Track Detector

    International Nuclear Information System (INIS)

    ZAKI, M.; ABDEL-NABY, A.; MORSY, A.

    2010-01-01

    Measurement of the neutron dose in and around the neutron sources is important for the purpose of personnel and environmental neutron dosimetry. In the present study, a method for the measurement of neutron dose using the UV-Vis spectra of CR-39 plastic track detector was investigated. A set of CR-39 plastic detectors was exposed to 252 Cf neutron source, which had the yield of 0.68x10 8 /s, and neutron dose equivalent rate 1m apart from the source is equal to 3.8 mrem/h. The samples were etched for 10 h in 6.25 N NaOH at 70 o C. The absorbance of the etched samples was measured using UV-visible spectrophotometer as a function of neutron dose. It was observed that there was a linear relationship between the optical absorption of these detectors and neutron dose. This means that the exposure dose of neutron can be determined by knowing the optical absorption of the sample. These results were compared with previous study. It was found that there was a matching and good agreement with their investigations.

  3. Fast simulation of the trigger system of the ATLAS detector at LHC

    International Nuclear Information System (INIS)

    Epp, B.; Ghete, V.M.; Kuhn, D.; Zhang, Y.J.

    2004-01-01

    The trigger system of the ATLAS detector aims to maximize the physics coverage and to be open to new and possibly unforeseen physics signatures. It is a multi-level system, composed from a hardware trigger at level-1, followed by the high-level-trigger (level-2 and event-filter). In order to understand its performance, to optimize it and to reduce its total cost, the trigger system requires a detailed simulation which is time- and resource-consuming. An alternative to the full detector simulation is a so-called 'fast simulation' which starts the analysis from particle level and replaces the full detector simulation and the detailed particle tracking with parametrized distributions obtained from the full simulation and/or a simplified detector geometry. The fast simulation offers a less precise description of trigger performance, but it is faster and less resource-consuming. (author)

  4. R and D on a New Technology of Micro-pattern Gaseous Detectors Fast Timing Micro-pattern Detector

    CERN Document Server

    Salva Diblen, Sinem

    2016-01-01

    After the upgrades of the Large Hadron Collider (LHC) planned for the second and the third Long Shutdown (LS), the LHC luminosity will approach very high values. Such conditions will affect the performance of the CMS muon system, especially in the very forward region, due to the harsh expected background environment and high pile-up conditions. The CMS collaboration considers upgrading the muon forward region to take advantage of the pixel tracking coverage extension a new detector, ME0 station, possibly behind the new forward calorimeter. New resistive micro-pattern gaseous detectors that are able to handle the very demanding spatial, time resolution and rate capability, are being considered. In this contribution we introduce a new type of MPGD technology the Fast Timing Micro-pattern (FTM) detector, utilizing a fully resistive WELL structure. It consists of a stack of several coupled layers where drift and WELL multiplication stages alternate in the structure, yielding a significant improvement in timing p...

  5. 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.

  6. Thermal and fast neutron dosimetry using artificial single crystal diamond detectors

    International Nuclear Information System (INIS)

    Angelone, M.; Pillon, M.; Prestopino, G.; Marinelli, Marco; Milani, E.; Verona, C.; Verona-Rinati, G.; Aielli, G.; Cardarelli, R.; Santonico, R.; Bedogni, R.; Esposito, A.

    2011-01-01

    In this work we propose the artificial Single Crystal Diamond (SCD) detector covered with a thin layer (0.5 μm/4 μm) of 6 LiF as a simultaneous thermal and fast neutron fluence monitor. Some interesting properties of the diamond response versus the neutron energy are evidenced thanks to Monte Carlo simulation using the MCNPX code which allows to propose the diamond detector also as an ambient dose equivalent (H∗(10)) monitor (REM counter).

  7. 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.

  8. Combined performance tests before installation of the ATLAS Semiconductor and Transition Radiation Tracking Detectors

    Czech Academy of Sciences Publication Activity Database

    Abat, E.; Abdesselam, A.; Andy, T.N.; Böhm, Jan; Šťastný, Jan

    2008-01-01

    Roč. 3, - (2008), P08003/1-P08003/67 ISSN 1748-0221 R&D Projects: GA MŠk LA08032; GA MŠk 1P04LA212 Institutional research plan: CEZ:AV0Z10100502 Keywords : solid state detectors * particle tracking detectors * large detector systems for particle and astroparticle physics * transition radiation detectors Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 0.333, year: 2008

  9. High-speed crystal detection and characterization using a fast-readout detector.

    Science.gov (United States)

    Aishima, Jun; Owen, Robin L; Axford, Danny; Shepherd, Emma; Winter, Graeme; Levik, Karl; Gibbons, Paul; Ashton, Alun; Evans, Gwyndaf

    2010-09-01

    A novel raster-scanning method combining continuous sample translation with the fast readout of a Pilatus P6M detector has been developed on microfocus beamline I24 at Diamond Light Source. This fast grid-scan tool allows the rapid evaluation of large sample volumes without the need to increase the beam size at the sample through changes in beamline hardware. A slow version is available for slow-readout detectors. Examples of grid-scan use in centring optically invisible samples and in detecting and characterizing numerous microcrystals on a mesh-like holder illustrate the most common applications of the grid scan now in routine use on I24.

  10. The influence of fast neutron irradiation on the noise properties of silicon surface-barrier detectors

    International Nuclear Information System (INIS)

    Dabrowski, W.; Korbel, K.

    1988-01-01

    The susceptibility to the fast neutron irradiation of silicon surface-barrier detectors has been investigated. It was shown that the 1/f-noise decreases substantially with increasing fluence in the range from 10 10 n/cm 2 to 10 11 n/cm 2 . The deterioration of the detector performance is caused mainly by the positively-charged defects induced by the radiation. The critical value of the neutron fluence, at which the detector performance begins to be worsened was also determined. 5 refs., 5 figs. (author)

  11. Photoconductive Detectors with Fast Temporal Response for Laser Produced Plasma Experiments

    International Nuclear Information System (INIS)

    M. J. May; C. Halvorson; T. Perry; F. Weber; P. Young; C. Silbernagel

    2008-01-01

    Processes during laser plasma experiments typically have time scales that are less than 100 ps. The measurement of these processes requires X-ray detectors with fast temporal resolution. We have measured the temporal responses and linearity of several different X-ray sensitive Photoconductive Detectors (PCDs). The active elements of the detectors investigated include both diamond (natural and synthetic) and GaAs crystals. The typical time responses of the GaAs PCDs are approximately 60 ps, respectively. Some characterizations using X-ray light from a synchrotron light source are presented

  12. Note: Fast neutron efficiency in CR-39 nuclear track detectors

    Energy Technology Data Exchange (ETDEWEB)

    Cavallaro, S. [Dipartimento di Fisica ed Astronomia,Università di Catania, Via S. Sofia 44, 95123 Catania, Italy and INFN-LNS, Via S. Sofia 42, 95123 Catania (Italy)

    2015-03-15

    CR-39 samples are commonly employed for fast neutron detection in fusion reactors and in inertial confinement fusion experiments. The literature reported efficiencies are strongly depending on experimental conditions and, in some cases, highly dispersed. The present note analyses the dependence of efficiency as a function of various parameters and experimental conditions in both the radiator-assisted and the stand-alone CR-39 configurations. Comparisons of literature experimental data with Monte Carlo calculations and optimized efficiency values are shown and discussed.

  13. CVD diamond based soft X-ray detector with fast response

    International Nuclear Information System (INIS)

    Li Fang; Hou Lifei; Su Chunxiao; Yang Guohong; Liu Shenye

    2010-01-01

    A soft X-ray detector has been made with high quality chemical vapor deposited (CVD) diamond and the electrical structure of micro-strip. Through the measurement of response time on a laser with the pulse width of 10 ps, the full width at half maximum of the data got in the oscilloscope was 115 ps. The rise time of the CVD diamond detector was calculated to be 49 ps. In the experiment on the laser prototype facility, the signal got by the CVD diamond detector was compared with that got by a soft X-ray spectrometer. Both signals coincided well. The detector is proved to be a kind of reliable soft X-ray detector with fast response and high signal-to-noise ratio. (authors)

  14. Using the pixel detector for fast triggering in CMS

    CERN Document Server

    De Mattai, M

    2006-01-01

    The Standard Model of fundamental interactions (SM) has been extensively tested in many particle experiments during the last 25 years and it has proven to be extremely successful up to the energy scale typical of the weak force. Nevertheless, there is still no experimental evidence of the Higgs boson, one of the key components of the SM, responsible for the breaking of the electroweak symmetry and for the masses of the fermions and of the weak bosons. The Large Hadron Collider (LHC) is scheduled to provide the first proton on proton collision in 2008 at the center of mass energy of 14 Tev, an energy one order of magnitude higher than the regime explored so far. The CMS experiment is an omni-purpose experiment that will operate at the LHC, it will give insight into Standard Model physics and search for physics beyond the Standard Model. In this work we consider the usage of pixel detector information in the reconstruction of hadronic jets in events collected by the CMS detector under high luminosity running co...

  15. Fast track trigger processor for the OPAL detector at LEP

    Energy Technology Data Exchange (ETDEWEB)

    Carter, A A; Carter, J R; Ward, D R; Heuer, R D; Jaroslawski, S; Wagner, A

    1986-09-20

    A fast hardware track trigger processor being built for the OPAL experiment is described. The processor will analyse data from the central drift chambers of OPAL to determine whether any tracks come from the interaction region, and thereby eliminate background events. The processor will find tracks over a large angular range, vertical strokecos thetavertical stroke < or approx. 0.95. The design of the processor is described, together with a brief account of its hardware implementation for OPAL. The results of feasibility studies are also presented.

  16. Fast "swarm of detectors" and their application in cosmic rays

    Science.gov (United States)

    Shoziyoev, G. P.; Shoziyoev, Sh. P.

    2017-06-01

    New opportunities in science appeared with the latest technology of the 21st century. This paper points to creating a new architecture for detection systems of different characteristics in astrophysics and geophysics using the latest technologies related to multicopter cluster systems, alternative energy sources, cluster technologies, cloud computing and big data. The idea of a quick-deployable scaleable dynamic system of a controlled drone with a small set of different detectors for detecting various components of extensive air showers in cosmic rays and in geophysics is very attractive. Development of this type of new system also allows to give a multiplier effect for the development of various sciences and research methods to observe natural phenomena.

  17. Signal and noise analysis in TRION-Time-Resolved Integrative Optical Fast Neutron detector

    International Nuclear Information System (INIS)

    Vartsky, D; Feldman, G; Mor, I; Goldberg, M B; Bar, D; Dangendorf, V

    2009-01-01

    TRION is a sub-mm spatial resolution fast neutron imaging detector, which employs an integrative optical time-of-flight technique. The detector was developed for fast neutron resonance radiography, a method capable of detecting a broad range of conventional and improvised explosives. In this study we have analyzed in detail, using Monte-Carlo calculations and experimentally determined parameters, all the processes that influence the signal and noise in the TRION detector. In contrast to event-counting detectors where the signal-to-noise ratio is dependent only on the number of detected events (quantum noise), in an energy-integrating detector additional factors, such as the fluctuations in imparted energy, number of photoelectrons, system gain and other factors will contribute to the noise. The excess noise factor (over the quantum noise) due to these processes was 4.3, 2.7, 2.1, 1.9 and 1.9 for incident neutron energies of 2, 4, 7.5, 10 and 14 MeV, respectively. It is shown that, even under ideal light collection conditions, a fast neutron detection system operating in an integrative mode cannot be quantum-noise-limited due to the relatively large variance in the imparted proton energy and the resulting scintillation light distributions.

  18. Comparative study of new 130mm diameter fast photomultipliers for neutron detectors

    International Nuclear Information System (INIS)

    Moszynski, M.; Costa, G.J.; Guillaume, G.; Heusch, B.; Huck, A.; Mouatassim, S.

    1991-01-01

    The present paper is a summary of the test measurements carried out using new 130 mm diameter fast photomultiplier tubes manufactured by Philips (France), EMI (England) and Hamamatsu (Japan), along with a comparison to the results obtained with the well known XP 2041 Philips model. These tubes will be used in large size neutron detectors

  19. 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

  20. DURIP: Fast Oscilloscope and Detectors for Air Laser Research

    Science.gov (United States)

    2015-01-01

    TEKTRONIX DPO73304D, 33 GHz Digital Phosphor Oscilloscope; 4 analog channels DPO70604C, 6 GHz Digital Phosphor Oscilloscope; 4 analog channels...when we focus in air intense UV pulses resonantly with two-photon transitions in atomic oxygen or nitrogen. The UV pump pulse (or an...two-­‐photon   UV  pumping  at  226nm  for  oxygen,  and  at  207  or  211nm  for   nitrogen   is   followed   by

  1. Fast loss analysis with LHC diamond detectors in 2017

    CERN Document Server

    Gorzawski, Arkadiusz; Fuster Martinez, Nuria; Garcia Morales, Hector; Mereghetti, Alessio; Cai, Xu; Valentino, Gianluca; Appleby, Robert Barrie; CERN. Geneva. ATS Department

    2018-01-01

    We presented some applications of the diamond BLM system installed in the LHC betatron collimation insertion. A selection of results illustrates the potential of this measurement system to understand better the losses at the LHC. Measurements range from the bunch-by-bunch analysis in different phases of the operational cycle, to the frequency analysis of fast losses. This work will continue in 2018, in collaboration with the various teams at CERN. New hardware is planned to improve the system. The addition of one monitor per beam will allow distinguishing the horizontal and vertical contents of losses at primary collimators, thus opening the possibility for a better understanding of loss mechanisms and for further study of correlation with other bunch-by-bunch measurements.

  2. A fast method for optical simulation of flood maps of light-sharing detector modules

    International Nuclear Information System (INIS)

    Shi, Han; Du, Dong; Xu, JianFeng; Moses, William W.; Peng, Qiyu

    2015-01-01

    Optical simulation of the detector module level is highly desired for Position Emission Tomography (PET) system design. Commonly used simulation toolkits such as GATE are not efficient in the optical simulation of detector modules with complicated light-sharing configurations, where a vast amount of photons need to be tracked. We present a fast approach based on a simplified specular reflectance model and a structured light-tracking algorithm to speed up the photon tracking in detector modules constructed with polished finish and specular reflector materials. We simulated conventional block detector designs with different slotted light guide patterns using the new approach and compared the outcomes with those from GATE simulations. While the two approaches generated comparable flood maps, the new approach was more than 200–600 times faster. The new approach has also been validated by constructing a prototype detector and comparing the simulated flood map with the experimental flood map. The experimental flood map has nearly uniformly distributed spots similar to those in the simulated flood map. In conclusion, the new approach provides a fast and reliable simulation tool for assisting in the development of light-sharing-based detector modules with a polished surface finish and using specular reflector materials.

  3. 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

  4. New Fast Response Thin Film-Based Superconducting Quench Detectors

    CERN Document Server

    Dudarev, A; van de Camp, W; Ravaioli, E; Teixeira, A; ten Kate, H H J

    2014-01-01

    Quench detection on superconducting bus bars and other devices with a low normal zone propagation velocity and low voltage build-up is quite difficult with conventional quench detection techniques. Currently, on ATLAS superconducting bus bar sections, superconducting quench detectors (SQD) are mounted to detect quench events. A first version of the SQD essentially consists of an insulated superconducting wire glued to a superconducting bus line or windings, which in the case of a quench rapidly builds up a relatively high resistance that can be easily and quietly detected. We now introduce a new generation of drastically improved SQDs. The new version makes the detection of quenches simpler, more reliable, and much faster. Instead of a superconducting wire, now a superconducting thin film is used. The layout of the sensor shows a meander like pattern that is etched out of a copper coated 25 mu m thick film of Nb-Ti glued in between layers of Kapton. Since the sensor is now much smaller and thinner, it is easi...

  5. Monte Carlo simulations of the particle transport in semiconductor detectors of fast neutrons

    International Nuclear Information System (INIS)

    Sedlačková, Katarína; Zaťko, Bohumír; Šagátová, Andrea; Nečas, Vladimír

    2013-01-01

    Several Monte Carlo all-particle transport codes are under active development around the world. In this paper we focused on the capabilities of the MCNPX code (Monte Carlo N-Particle eXtended) to follow the particle transport in semiconductor detector of fast neutrons. Semiconductor detector based on semi-insulating GaAs was the object of our investigation. As converter material capable to produce charged particles from the (n, p) interaction, a high-density polyethylene (HDPE) was employed. As the source of fast neutrons, the 239 Pu–Be neutron source was used in the model. The simulations were performed using the MCNPX code which makes possible to track not only neutrons but also recoiled protons at all interesting energies. Hence, the MCNPX code enables seamless particle transport and no other computer program is needed to process the particle transport. The determination of the optimal thickness of the conversion layer and the minimum thickness of the active region of semiconductor detector as well as the energy spectra simulation were the principal goals of the computer modeling. Theoretical detector responses showed that the best detection efficiency can be achieved for 500 μm thick HDPE converter layer. The minimum detector active region thickness has been estimated to be about 400 μm. -- Highlights: ► Application of the MCNPX code for fast neutron detector design is demonstrated. ► Simulations of the particle transport through conversion film of HDPE are presented. ► Simulations of the particle transport through detector active region are presented. ► The optimal thickness of the HDPE conversion film has been calculated. ► Detection efficiency of 0.135% was reached for 500 μm thick HDPE conversion film

  6. 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

  7. Elsevier R&D on a new type of micropattern gaseous detector: The Fast Timing Micropattern detector

    CERN Document Server

    Abbaneo, D; Abbrescia, M; Abi Akl, M; Aboamer, O; Acosta, D; Ahmad, A; Ahmed, W; Aleksandrov, A; Altieri, P; Asawatangtrakuldee, C; Aspell, P; Assran, Y; Awan, I; Bally, S; Ban, Y; Banerjee, S; Barashko, V; Barria, P; Bencze, G; Beni, N; Benussi, L; Bhopatkar, V; Bianco, S; Bos, J; Bouhali, O; Braghieri, A; Braibant, S; Buontempo, S; Calabria, C; Caponero, M; Caputo, C; Cassese, F; Castaneda, A; Cauwenbergh, S; Cavallo, F R; Celik, A; Choi, M; Choi, S; Christiansen, J; Cimmino, A; Colafranceschi, S; Colaleo, A; Conde Garcia, A; Czellar, S; Dabrowski, M M; De Lentdecker, G; Oliveira, R De; De Robertis, G; Dildick, S; Dorney, B; Endroczi, G; Errico, F; Fallavollita, F; Fenyvesi, A; Ferry, S; Furic, I; Giacomelli, P; Gilmore, J; Golovtsov, V; Guiducci, L; Guilloux, F; Gutierrez, A; Hadjiiska, R M; Hauser, J; Hoepfner, K; Hohlmann, M; Hoorani, H; Iaydjiev, P; Jeng, Y G; Kamon, T; Karchin, P; Korytov, A; Krutelyov, S; Kumar, A; Kim, H; Lee, J; Lenzi, T; Litov, L; Loddo, F; Madorsky, A; Maerschalk, T; Maggi, M; Magnani, A; Mal, P K; Mandal, K; Marchioro, A; Marinov, A; Majumdar, N; Merlin, J A; Mitselmakher, G; Mohanty, A K; Mohapatra, A; Molnar, J; Muhammad, S; Mukhopadhyay, S; Naimuddin, M; Nuzzo, S; Oliveri, E; Pant, L M; Paolucci, P; Park, I; Passeggio, G; Pavlov, B; Philipps, B; Piccolo, D; Postema, H; Puig Baranac, A; Radi, A; Radogna, R; Raffone, G; Ranieri, A; Rashevski, G; Ressegotti, M; Riccardi, C; Rodozov, M; Rodrigues, A; Ropelewski, L; RoyChowdhury, S; Ryu, G; Ryu, M S; Safonov, A; Salva, S; Saviano, G; Sharma, A; Sharma, A; Sharma, R; Shah, A H; Shopova, M; Sturdy, J; Sultanov, G; Swain, S K; Szillasi, Z; Talvitie, J; Tatarinov, A; Tuuva, T; Tytgat, M; Vai, I; Van Stenis, M; Venditti, R; Verhagen, E; Verwilligen, P; Vitulo, P; Volkov, S; Vorobyev, A; Wang, D; Wang, M; Yang, U; Yang, Y; Yonamine, R; Zaganidis, N; Zenoni, F; Zhang, A

    2017-01-01

    Micropattern gaseous detectors (MPGD) underwent significant upgrades in recent years, introducing resistive materials to build compact spark-protected devices. Exploiting this technology further, various features such as space and time resolution, rate capability, sensitive area, operational stability and radiation hardness can be improved. This contribution introduces a new type of MPGD, namely the Fast Timing Micropattern (FTM) detector, utilizing a fully resistive WELL structure. It consists of a stack of several coupled layers where drift and WELL multiplication stages alternate in the structure, yielding a significant improvement in timing properties due to competing ionization processes in the different drift regions. Two FTM prototypes have been developed so far. The first one is uWELL-like, where multiplication takes place in the holes of a kapton foil covered on both sides with resistive material. The second one has a resistive Micromegas-like structure, with multiplication developing in a region del...

  8. Fast neutron spectroscopy with tensioned metastable fluid detectors

    Energy Technology Data Exchange (ETDEWEB)

    Grimes, T.F.; Taleyarkhan, R.P., E-mail: rusi@purdue.edu

    2016-09-11

    This paper describes research into development of a rapid-turnaround, neutron-spectroscopy capable (gamma-beta blind), high intrinsic efficiency sensor system utilizing the tensioned metastable fluid detector (TMFD) architecture. The inability of prevailing theoretical models (developed successfully for the classical bubble chamber) to adequately predict detection thresholds for tensioned metastable fluid conditions is described. Techniques are presented to overcome these inherent shortcomings, leading thereafter, to allow successful neutron spectroscopy using TMFDs – via the newly developed Single Atom Spectroscopy (SAS) approach. SAS also allows for a unique means for rapidly determining neutron energy thresholds with TMFDs. This is accomplished by simplifying the problem of determining Cavitation Detection Events (CDEs) arising from neutron interactions with one in which several recoiling atom species contribute to CDEs, to one in which only one dominant recoil atom need be considered. The chosen fluid is Heptane (C{sub 7}H{sub 16}) for which only recoiling C atoms contribute to CDEs. Using the SAS approach, the threshold curve for Heptane was derived using isotope neutron source data, and then validated against experiments with mono-energetic (2.45/14 MeV) neutrons from D-D and D-T accelerators. Thereafter the threshold curves were used to produce the response matrix for various geometries. The response matrices were in turn combined with experimental data to recover the continuous spectra of fission (Cf-252) and (α,n) Pu–Be isotopic neutron sources via an unfolding algorithm. A generalized algorithm is also presented for performing neutron spectroscopy using any other TMFD fluid that meets the SAS approach assumptions.

  9. 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.

  10. Use of M and L transitions of heavy elements for the determination of a Si(Li) detector's efficiency

    International Nuclear Information System (INIS)

    Morales, J.R.; Romo, C.; Dinator, M.I.; Llona, F.; Tabacniks, M.

    1987-01-01

    The verification of the Si(Li) cryogenic detector's efficiency may be fastly carried out using the M radiations of the heavy elements, such as Pb and Au. Thin targets have been bombarded with protons of 2.0 and 6.6 MeV, thus resulting the transitions M and L. The number of emitted photons are possible to be inferred using tabulated cross sections from different authors. The comparison with the number of photons registered allows to determine the efficiency. (S.M.) [es

  11. A Fast Monte Carlo Simulation for the International Linear Collider Detector

    International Nuclear Information System (INIS)

    Furse, D.

    2005-01-01

    The following paper contains details concerning the motivation for, implementation and performance of a Java-based fast Monte Carlo simulation for a detector designed to be used in the International Linear Collider. This simulation, presently included in the SLAC ILC group's org.lcsim package, reads in standard model or SUSY events in STDHEP file format, stochastically simulates the blurring in physics measurements caused by intrinsic detector error, and writes out an LCIO format file containing a set of final particles statistically similar to those that would have found by a full Monte Carlo simulation. In addition to the reconstructed particles themselves, descriptions of the calorimeter hit clusters and tracks that these particles would have produced are also included in the LCIO output. These output files can then be put through various analysis codes in order to characterize the effectiveness of a hypothetical detector at extracting relevant physical information about an event. Such a tool is extremely useful in preliminary detector research and development, as full simulations are extremely cumbersome and taxing on processor resources; a fast, efficient Monte Carlo can facilitate and even make possible detector physics studies that would be very impractical with the full simulation by sacrificing what is in many cases inappropriate attention to detail for valuable gains in time required for results

  12. 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)

  13. A Fast Event Preprocessor and Sequencer for the Simbol-X Low Energy Detector

    Science.gov (United States)

    Schanz, T.; Tenzer, C.; Maier, D.; Kendziorra, E.; Santangelo, A.

    2009-05-01

    The Simbol-X Low Energy Detector (LED), a 128×128 pixel DEPFET (Depleted Field Effect Transistor) array, will be read out at a very high rate (8000 frames/second) and, therefore, requires a very fast on board electronics. We present an FPGA-based LED camera electronics consisting of an Event Preprocessor (EPP) for on board data preprocessing and filtering of the Simbol-X low-energy detector and a related Sequencer (SEQ) to generate the necessary signals to control the readout.

  14. A Fast Event Preprocessor and Sequencer for the Simbol-X Low Energy Detector

    International Nuclear Information System (INIS)

    Schanz, T.; Tenzer, C.; Maier, D.; Kendziorra, E.; Santangelo, A.

    2009-01-01

    The Simbol-X Low Energy Detector (LED), a 128x128 pixel DEPFET (Depleted Field Effect Transistor) array, will be read out at a very high rate (8000 frames/second) and, therefore, requires a very fast on board electronics. We present an FPGA-based LED camera electronics consisting of an Event Preprocessor (EPP) for on board data preprocessing and filtering of the Simbol-X low-energy detector and a related Sequencer (SEQ) to generate the necessary signals to control the readout.

  15. Unified Dark Matter scalar field models with fast transition

    Energy Technology Data Exchange (ETDEWEB)

    Bertacca, Daniele [Dipartimento di Fisica Galileo Galilei, Università di Padova, via F. Marzolo 8, I-35131 Padova (Italy); Bruni, Marco [Institute of Cosmology and Gravitation, University of Portsmouth, Dennis Sciama Building, Portsmouth, PO1 3FX (United Kingdom); Piattella, Oliver F. [Department of Physics, Universidade Federal do Espírito Santo, avenida Ferrari 514, 29075-910, Vitória, ES (Brazil); Pietrobon, Davide, E-mail: daniele.bertacca@pd.infn.it, E-mail: marco.bruni@port.ac.uk, E-mail: oliver.piattella@gmail.com, E-mail: davide.pietrobon@jpl.nasa.gov [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, 91109 Pasadena CA U.S.A. (United States)

    2011-02-01

    We investigate the general properties of Unified Dark Matter (UDM) scalar field models with Lagrangians with a non-canonical kinetic term, looking specifically for models that can produce a fast transition between an early Einstein-de Sitter CDM-like era and a later Dark Energy like phase, similarly to the barotropic fluid UDM models in JCAP01(2010)014. However, while the background evolution can be very similar in the two cases, the perturbations are naturally adiabatic in fluid models, while in the scalar field case they are necessarily non-adiabatic. The new approach to building UDM Lagrangians proposed here allows to escape the common problem of the fine-tuning of the parameters which plague many UDM models. We analyse the properties of perturbations in our model, focusing on the the evolution of the effective speed of sound and that of the Jeans length. With this insight, we can set theoretical constraints on the parameters of the model, predicting sufficient conditions for the model to be viable. An interesting feature of our models is that what can be interpreted as w{sub DE} can be < −1 without violating the null energy conditions.

  16. Initial angle resolved measurements of fast neutrals using a multichannel linear AXUV detector system on LHD

    International Nuclear Information System (INIS)

    Veshchev, E. A.; Ozaki, T.; Goncharov, P. R.; Sudo, S.

    2006-01-01

    A new multichannel diagnostic for fast ion distribution studies has been developed and successfully tested on the Large Helical Device (LHD) in different plasma heating conditions. The diagnostic is based on a linear array AXUV detector consisting of 20 segments, charge sensitive preamplifiers, and a set of pulse height analysis channels. The main advantage of this system is the possibility to make time, energy, and angle-resolved measurements of charge exchange neutral particles in a single plasma discharge. This feature makes the new diagnostic a very helpful and powerful tool intended to contribute to the understanding of fast ion behavior in a complex helical plasma geometry like the one of LHD

  17. Numerical study of the particle transport in fast neutron detectors with conversion layer

    International Nuclear Information System (INIS)

    Sedlackova, K.; Zatko, B.; Necas, V.

    2012-01-01

    This paper deals with fast neutron and recoil proton transport simulation using statistical analysis of Monte Carlo radiation transport code (MCNPX). Its possibilities in the detector design and optimization are presented. MCNPX proved as a very advantageous self-contained simulation program for fast neutron and secondary proton tracking. Simulations of respective particle transport through conversion layer of HDPE and further in the active volume of detector let us to follow important characteristics as neutron/proton flux density, reaction rate of elastic scattering on hydrogen nuclei and deposited energy as well as their dependencies on incident neutron energy and conversion layer/active region thickness. The efficiency of neutrons to protons conversion has been calculated and its maximum was reached for 500 μm thick conversion layer. The minimum active region thickness has been estimated to be about 300 μm.(authors)

  18. A Search for Fast Moving Magnetic Monopoles with the MACRO Detector

    Science.gov (United States)

    Liu, Rongzhi

    1995-01-01

    From Dirac monopole theory to modern GUT's (Grand Unified Theories), magnetic monopoles have attracted much attention from physicists. While Dirac had demonstrated the consistency of magnetic monopoles with quantum eletrodynamics, 't Hooft and Polyakov demonstrated the necessity of monopoles in GUT's. Furthermore, the GUT's supply more clues about magnetic monopoles, including their exceptionally heavy masses ~ 10^{16 } GeV. Both current theories and previous monopole experiments have suggested that the flux of magnetic monopoles is likely to be very small, so it is necessary to have a large area detector to search for them. This thesis presents a search for fast moving magnetic monopoles with the MACRO detector. The MACRO detector is a large underground detector located at Gran Sasso, Italy. Its primary goal is to search for magnetic monopoles at a flux level beyond the Parker bound. It is underground at 3,000 meters water equivalent depth, with a nominal acceptance of 10,000 m^2 sr. It employs liquid scintillator counters, streamer tubes and track-etch detectors which can supply both independent and cross checks for fast monopole candidate events. This search is mainly based on the liquid scintillator counters with primary event selection and energy reconstruction from the ERP system. The 6.2 mus trigger time is based on the time of flight of a fast moving monopole diagonally through one supermodule with a velocity ~ 10^{-2}c. The search uses the "six-month-run" data which were taken from December of 1992 to July of 1993 with the operation of the lower part of the detector. With energy reconstruction ability up to 8 GeV with 22% error, we apply a double-face high energy requirement to reject most muon events from the data sample. We then apply the WFD, streamer tube and strip information to reject non-monopole events. The live time for this analysis is 5,300 hours, with acceptance of 4050 m^2 sr. With no fast monopole candidate event found, we establish an upper

  19. Towards radiation hard converter material for SiC-based fast neutron detectors

    Science.gov (United States)

    Tripathi, S.; Upadhyay, C.; Nagaraj, C. P.; Venkatesan, A.; Devan, K.

    2018-05-01

    In the present work, Geant4 Monte-Carlo simulations have been carried out to study the neutron detection efficiency of the various neutron to other charge particle (recoil proton) converter materials. The converter material is placed over Silicon Carbide (SiC) in Fast Neutron detectors (FNDs) to achieve higher neutron detection efficiency as compared to bare SiC FNDs. Hydrogenous converter material such as High-Density Polyethylene (HDPE) is preferred over other converter materials due to the virtue of its high elastic scattering reaction cross-section for fast neutron detection at room temperature. Upon interaction with fast neutrons, hydrogenous converter material generates recoil protons which liberate e-hole pairs in the active region of SiC detector to provide a detector signal. The neutron detection efficiency offered by HDPE converter is compared with several other hydrogenous materials viz., 1) Lithium Hydride (LiH), 2) Perylene, 3) PTCDA . It is found that, HDPE, though providing highest efficiency among various studied materials, cannot withstand high temperature and harsh radiation environment. On the other hand, perylene and PTCDA can sustain harsh environments, but yields low efficiency. The analysis carried out reveals that LiH is a better material for neutron to other charge particle conversion with competent efficiency and desired radiation hardness. Further, the thickness of LiH has also been optimized for various mono-energetic neutron beams and Am-Be neutron source generating a neutron fluence of 109 neutrons/cm2. The optimized thickness of LiH converter for fast neutron detection is found to be ~ 500 μm. However, the estimated efficiency for fast neutron detection is only 0.1%, which is deemed to be inadequate for reliable detection of neutrons. A sensitivity study has also been done investigating the gamma background effect on the neutron detection efficiency for various energy threshold of Low-Level Discriminator (LLD). The detection

  20. The ''Flight Chamber'': A fast, large area, zero-time detector

    International Nuclear Information System (INIS)

    Trautner, N.

    1976-01-01

    A new, fast, zero-time detector with an active area of 20 cm 2 has been constructed. Secondary electrons from a thin self-supporting foil are accelerated onto a scinitllator. The intrinsic time resolution (fwhm) was 0.85 for 5.5 MeV α-particles and 0.42 ns for 17 MeV 16 O-ions, at an efficiency of 97.5% and 99.6%, respectively. (author)

  1. Properties of SiC semiconductor detector of fast neutrons investigated using MCNPX code

    International Nuclear Information System (INIS)

    Sedlakova, K.; Sagatova, A.; Necas, V.; Zatko, B.

    2013-01-01

    The potential of silicon carbide (SiC) for use in semiconductor nuclear radiation detectors has been long recognized. The wide bandgap of SiC (3.25 eV for 4H-SiC polytype) compared to that for more conventionally used semiconductors, such as silicon (1.12 eV) and germanium (0.67 eV), makes SiC an attractive semiconductor for use in high dose rate and high ionization nuclear environments. The present work focused on the simulation of particle transport in SiC detectors of fast neutrons using statistical analysis of Monte Carlo radiation transport code MCNPX. Its possibilities in detector design and optimization are presented.(authors)

  2. Measurements of possible type inversion in silicon junction detectors by fast neutron irradiation

    International Nuclear Information System (INIS)

    Li, Z.; Kraner, H.W.

    1991-05-01

    The successful application of silicon position sensitive detectors in experiments at the SSC or LHC depends on an accurate assessment of the radiation tolerance of this detector species. In particular, fast neutrons (E av = 1 MeV) produce bulk displacement damage that is projected, from estimated fluences, to cause increased generation (leakage) current, charge collection deficiencies, resistivity changes and possibly semiconductor type change or inversion. Whereas the leakage current increase was believed to be the major concern for estimated fluences of 10 12 n/cm 2 experiment year at the initial SSC luminosity of 10 33 /cm 2 -sec, increased luminosity and exposure time has raised the possible exposure to 10 14 n/cm 2 , which opens the door for the several other radiation effects suggested above to play observable and significant roles in detector degradation or change. 17 refs., 19 figs

  3. Fast neutron detection by means of an organic solid state track detector

    International Nuclear Information System (INIS)

    Doerschel, B.; Streubel, G.

    1980-01-01

    Solid state track detectors consisting of cellulose triacetate foils are appropriate for measuring the fast neutron fluence without applying external radiators. Detector sensitivity has been determined as a function of neutron energy by performing irradiations with various neutron sources and monoenergetic neutrons of different energies. A comparison with theoretical results given in the literature for a simple model of track recording has shown sufficient agreement. The measuring errors and the influence of spectral changes in the neutron field on detector response are discussed for the studied method of fluence measurement. By means of these errors the measuring range has been determined for well defined irradiation conditions, taking into account spectral changes in the neutron field. (author)

  4. Evaluation of high performance data acquisition boards for simultaneous sampling of fast signals from PET detectors

    International Nuclear Information System (INIS)

    Judenhofer, Martin S; Pichler, Bernd J; Cherry, Simon R

    2005-01-01

    Detectors used for positron emission tomography (PET) provide fast, randomly distributed signals that need to be digitized for further processing. One possibility is to sample the signals at the peak initiated by a trigger from a constant fraction discriminator (CFD). For PET detectors, simultaneous acquisition of many channels is often important. To develop and evaluate novel PET detectors, a flexible, relatively low cost and high performance laboratory data acquisition (DAQ) system is therefore required. The use of dedicated DAQ systems, such as a multi-channel analysers (MCAs) or continuous sampling boards at high rates, is expensive. This work evaluates the suitability of well-priced peripheral component interconnect (PCI)-based 8-channel DAQ boards (PD2-MFS-8 2M/14 and PD2-MFS-8-500k/14, United Electronic Industries Inc., Canton, MA, USA) for signal acquisition from novel PET detectors. A software package was developed to access the board, measure basic board parameters, and to acquire, visualize, and analyse energy spectra and position profiles from block detectors. The performance tests showed that the boards input linearity is >99.2% and the standard deviation is 22 Na source was 14.9% (FWHM) at 511 keV and is slightly better than the result obtained with a high-end single channel MCA (8000A, Amptek, USA) using the same detector (16.8%). The crystals (1.2 x 1.2 x 12 mm 3 ) within a 9 x 9 LSO block detector could be clearly separated in an acquired position profile. Thus, these boards are well suited for data acquisition with novel detectors developed for nuclear imaging

  5. A directional fast neutron detector using scintillating fibers and an intensified CCD camera system

    International Nuclear Information System (INIS)

    Holslin, Daniel; Armstrong, A.W.; Hagan, William; Shreve, David; Smith, Scott

    1994-01-01

    We have been developing and testing a scintillating fiber detector (SFD) for use as a fast neutron sensor which can discriminate against neutrons entering at angles non-parallel to the fiber axis (''directionality''). The detector/convertor component is a fiber bundle constructed of plastic scintillating fibers each measuring 10 cm long and either 0.3 mm or 0.5 mm in diameter. Extensive Monte Carlo simulations were made to optimize the bundle response to a range of fast neutron energies and to intense fluxes of high energy gamma-rays. The bundle is coupled to a set of gamma-ray insenitive electro-optic intensifiers whose output is viewed by a CCD camera directly coupled to the intensifiers. Two types of CCD cameras were utilized: 1) a standard, interline RS-170 camera with electronic shuttering and 2) a high-speed (up to 850 frame/s) field-transfer camera. Measurements of the neutron detection efficiency and directionality were made using 14 MeV neutrons, and the response to gamma-rays was performed using intense fluxes from radioisotopic sources (up to 20 R/h). Recently, the detector was constructed and tested using a large 10 cm by 10 cm square fiber bundle coupled to a 10 cm diameter GEN I intensifier tube. We present a description of the various detector systems and report the results of experimental tests. ((orig.))

  6. Fast digitization and discrimination of prompt neutron and photon signals using a novel silicon carbide detector

    International Nuclear Information System (INIS)

    Brandon W. Blackburn; James T. Johnson; Scott M. Watson; David L. Chichester; James L. Jones; Frank H. Ruddy; John G. Seidel; Robert W. Flammang

    2007-01-01

    Current requirements of some Homeland Security active interrogation projects for the detection of Special Nuclear Material (SNM) necessitate the development of faster inspection and acquisition capabilities. In order to do so, fast detectors which can operate during and shortly after intense interrogation radiation flashes are being developed. Novel silicon carbide (SiC) semiconductor Schottky diodes have been utilized as robust neutron and photon detectors in both pulsed photon and pulsed neutron fields and are being integrated into active inspection environments to allow exploitation of both prompt and delayed emissions. These detectors have demonstrated the capability of detecting both photon and neutron events during intense photon flashes typical of an active inspection environment. Beyond the inherent insensitivity of SiC to gamma radiation, fast digitization and processing has demonstrated that pulse shape discrimination (PSD) in combination with amplitude discrimination can further suppress unwanted gamma signals and extract fast neutron signatures. Usable neutron signals have been extracted from mixed radiation fields where the background has exceeded the signals of interest by >1000:1

  7. High-Sensitivity Fast Neutron Detector KNK-2-8M

    Science.gov (United States)

    Koshelev, A. S.; Dovbysh, L. Ye.; Ovchinnikov, M. A.; Pikulina, G. N.; Drozdov, Yu. M.; Chuklyaev, S. V.; Pepyolyshev, Yu. N.

    2017-12-01

    The design of the fast neutron detector KNK-2-8M is outlined. The results of he detector study in the pulse counting mode with pulses from 238U nuclei fission in the radiator of the neutron-sensitive section and in the current mode with separation of functional section currents are presented. The possibilities of determination of the effective number of 238U nuclei in the radiator of the neutron-sensitive section are considered. The diagnostic capabilities of the detector in the counting mode are demonstrated, as exemplified by the analysis of reference data on characteristics of neutron fields in the BR-1 reactor hall. The diagnostic capabilities of the detector in the current mode are demonstrated, as exemplified by the results of measurements of 238U fission intensity in the power startup of the BR-K1 reactor in the fission pulse generation mode with delayed neutrons and the detector placed in the reactor cavity in conditions of large-scale variation of the reactor radiation fields.

  8. High-sensitivity fast neutron detector KNK-2-7M

    Energy Technology Data Exchange (ETDEWEB)

    Koshelev, A. S., E-mail: alexsander.coshelev@yandex.ru; Dovbysh, L. Ye.; Ovchinnikov, M. A.; Pikulina, G. N.; Drozdov, Yu. M. [Russian Federal Nuclear Center All-Russian Research Institute of Experimental Physics (Russian Federation); Chuklyaev, S. V. [Research Institute of Materials Technology (Russian Federation)

    2015-12-15

    The construction of the fast neutron detector KNK-2-7M is briefly described. The results of the study of the detector in the pulse-counting mode are given for the fissions of {sup 237}Np nuclei in the radiator of the neutron-sensitive section and in the current mode with the separation of sectional currents of functional sections. The possibilities of determining the effective number of {sup 237}Np nuclei in the radiator of the neutronsensitive section are considered. The diagnostic possibilities of the detector in the counting mode are shown by example of the analysis of the reference data from the neutron-field characteristics in the working hall of the BR-K1 reactor. The diagnostic possibilities of the detector in the current operating mode are shown by example of the results of measuring the {sup 237}Np-fission intensity in the BR-K1 reactor power start-ups implemented in the mode of fission-pulse generation on delayed neutrons at the detector arrangement inside the reactor core cavity under conditions of a wide variation of the reactor radiation field.

  9. Time response of fast-gated microchannel plates used as x-ray detectors

    International Nuclear Information System (INIS)

    Turner, R.E.; Bell, P.; Hanks, R.; Kilkenny, J.D.; Landen, N.; Power, G.; Wiedwald, J.; Meier, M.

    1990-01-01

    We report measurements of the time response of fast-gated, micro- channel plate (MCP) detectors, using a <10 ps pulsewidth ultra-violet laser and an electronic sampling system to measure time resolutions to better than 25 ps. The results show that framing times of less than 100 ps are attainable with high gain. The data is compared to a Monte Carlo calculation, which shows good agreement. We also measured the relative sensitivity as a function of DC bias, and saturation effects for large signal inputs. In part B, we briefly describe an electrical ''time-of-flight'' technique, which we have used to measure the response time of a fast-gated microchannel plate (MCP). Thinner MCP's than previously used have been tested, and, as expected, show fast gating times and smaller electron multiplication. A preliminary design for an x-ray pinhole camera, using a thin MCP, is presented. 7 refs., 6 figs

  10. The sensitivity calibration of the ultra-fast quench plastic scintillation detector for D-T neutrons

    International Nuclear Information System (INIS)

    Tang Changhuan; Yan Meiqiong; Xie Chaomei

    1998-01-01

    The authors introduce some characteristics of ultra-fast quench plastic scintillation detectors. When the detectors are composed of different scintillators, light guides and microchannel plate photomultiplier tube (MCP-PMT), their sensitivities to D-T neutrons are calibrated by a pulse neutron tube with a neutron pulse width about 10 ns

  11. A transition radiation detector for RHIC featuring accurate tracking and dE/dx particle identification

    Energy Technology Data Exchange (ETDEWEB)

    O`Brien, E.; Lissauer, D.; McCorkle, S.; Polychronakos, V.; Takai, H. [Brookhaven National Lab., Upton, NY (United States); Chi, C.Y.; Nagamiya, S.; Sippach, W.; Toy, M.; Wang, D.; Wang, Y.F.; Wiggins, C.; Willis, W. [Columbia Univ., New York, NY (United States); Cherniatin, V.; Dolgoshein, B. [Moscow Institute of Physics and Engineering, (Russian Federation); Bennett, M.; Chikanian, A.; Kumar, S.; Mitchell, J.T.; Pope, K. [Yale Univ., New Haven, CT (United States)

    1991-12-31

    We describe the results of a test ran involving a Transition Radiation Detector that can both distinguish electrons from pions which momenta greater titan 0.7 GeV/c and simultaneously track particles passing through the detector. The particle identification is accomplished through a combination of the detection of Transition Radiation from the electron and the differences in electron and pion energy loss (dE/dx) in the detector. The dE/dx particle separation is most, efficient below 2 GeV/c while particle ID utilizing Transition Radiation effective above 1.5 GeV/c. Combined, the electron-pion separation is-better than 5 {times} 10{sup 2}. The single-wire, track-position resolution for the TRD is {approximately}230 {mu}m.

  12. A transition radiation detector which features accurate tracking and dE/dx particle identification

    International Nuclear Information System (INIS)

    O'Brien, E.; Lissauer, D.; McCorkle, S.; Polychronakos, V.; Takai, H.; Chi, C.Y.; Nagamiya, S.; Sippach, W.; Toy, M.; Wang, D.; Wang, Y.F.; Wiggins, C.; Willis, W.; Cherniatin, V.; Dolgoshein, B.; Bennett, M.; Chikanian, A.; Kumar, S.; Mitchell, J.T.; Pope, K.

    1991-01-01

    We describe the results of a test run involving a Transition Radiation Detector that can both distinguish electrons from pions with momenta greater than 0.7 GeV/c and simultaneously track particles passing through the detector. The particle identification is accomplished through a combination of the detection of Transition Radiation from the electron and the differences in electron and pion energy loss (dE/dx) in the detector. The dE/dx particle separation is most efficient below 2 GeV/c while particle ID utilizing Transition Radiation is effective above 1.5 GeV/c. Combined, the electron-pion separation is better than 5 x l0 2 . The single-wire, track-position resolution for the TRD is ∼230μm

  13. Alanine and TLD coupled detectors for fast neutron dose measurements in neutron capture therapy (NCT)

    Energy Technology Data Exchange (ETDEWEB)

    Cecilia, A.; Baccaro, S.; Cemmi, A. [ENEA-FIS-ION, Casaccia RC, Via Anguillarese 301, 00060 Santa Maria di Galeria, Rome (Italy); Colli, V.; Gambarini, G. [Dept. of Physics of the Univ., INFN, Via Celoria 16, 20133 Milan (Italy); Rosi, G. [ENEA-FIS-ION, Casaccia RC, Via Anguillarese 301, 00060 Santa Maria di Galeria, Rome (Italy); Scolari, L. [Dept. of Physics of the Univ., INFN, Via Celoria 16, 20133 Milan (Italy)

    2004-07-01

    A method was investigated to measure gamma and fast neutron doses in phantoms exposed to an epithermal neutron beam designed for neutron capture therapy (NCT). The gamma dose component was measured by TLD-300 [CaF{sub 2}:Tm] and the fast neutron dose, mainly due to elastic scattering with hydrogen nuclei, was measured by alanine dosemeters [CH{sub 3}CH(NH{sub 2})COOH]. The gamma and fast neutron doses deposited in alanine dosemeters are very near to those released in tissue, because of the alanine tissue equivalence. Couples of TLD-300 and alanine dosemeters were irradiated in phantoms positioned in the epithermal column of the Tapiro reactor (ENEA-Casaccia RC). The dosemeter response depends on the linear energy transfer (LET) of radiation, hence the precision and reliability of the fast neutron dose values obtained with the proposed method have been investigated. Results showed that the combination of alanine and TLD detectors is a promising method to separate gamma dose and fast neutron dose in NCT. (authors)

  14. A fast event preprocessor for the Simbol-X Low-Energy Detector

    Science.gov (United States)

    Schanz, T.; Tenzer, C.; Kendziorra, E.; Santangelo, A.

    2008-07-01

    The Simbol-X1 Low Energy Detector (LED), a 128 × 128 pixel DEPFET array, will be read out very fast (8000 frames/second). This requires a very fast onboard data preprocessing of the raw data. We present an FPGA based Event Preprocessor (EPP) which can fulfill this requirements. The design is developed in the hardware description language VHDL and can be later ported on an ASIC technology. The EPP performs a pixel related offset correction and can apply different energy thresholds to each pixel of the frame. It also provides a line related common-mode correction to reduce noise that is unavoidably caused by the analog readout chip of the DEPFET. An integrated pattern detector can block all invalid pixel patterns. The EPP has an internal pipeline structure and can perform all operation in realtime (< 2 μs per line of 64 pixel) with a base clock frequency of 100 MHz. It is utilizing a fast median-value detection algorithm for common-mode correction and a new pattern scanning algorithm to select only valid events. Both new algorithms were developed during the last year at our institute.

  15. Inorganic Surface Coating with Fast Wetting-Dewetting Transitions for Liquid Manipulations.

    Science.gov (United States)

    Yang, Yajie; Zhang, Liaoliao; Wang, Jue; Wang, Xinwei; Duan, Libing; Wang, Nan; Xiao, Fajun; Xie, Yanbo; Zhao, Jianlin

    2018-06-06

    Liquid manipulation is a fundamental issue for microfluidics and miniaturized sensors. Fast wetting-state transitions by optical methods have proven being efficient for liquid manipulations by organic surface coatings, however rarely been achieved by using inorganic coatings. Here, we report a fast optical-induced wetting-state transition surface achieved by inorganic coating, enabling tens of second transitions for a wetting-dewetting cycle, shortened from an hour, as typically reported. Here, we demonstrate a gravity-driven microfluidic reactor and switch it to a mixer after a second-step exposure in a minimum of within 80 s of UV exposure. The fast wetting-dewetting transition surfaces enable the fast switchable or erasable smart surfaces for water collection, miniature chemical reaction, or sensing systems by using inorganic surface coatings.

  16. Obstacle detectors for automated transit vehicles: A technoeconomic and market analysis

    Science.gov (United States)

    Lockerby, C. E.

    1979-01-01

    A search was conducted to identify the technical and economic characteristics of both NASA and nonNASA obstacle detectors. The findings, along with market information were compiled and analyzed for consideration by DOT and NASA in decisions about any future automated transit vehicle obstacle detector research, development, or applications project. Currently available obstacle detectors and systems under development are identified by type (sonic, capacitance, infrared/optical, guided radar, and probe contact) and compared with the three NASA devices selected as possible improvements or solutions to the problems in existing obstacle detection systems. Cost analyses and market forecasts individually for the AGT and AMTV markets are included.

  17. Fast polycrystalline CdTe detectors for bunch-by-bunch luminosity monitoring in the LHC

    CERN Document Server

    Brambilla, A; Jolliot, M; Bravin, E

    2008-01-01

    The luminosity at the four interaction points of the Large Hadron Collider (LHC) must be continuously monitored in order to provide an adequate tool for the control and optimisation of beam parameters. Polycrystalline cadmium telluride (CdTe) detectors have previously been tested, showing their high potential to fulfil the requirements of luminosity measurement in the severe environment of the LHC interaction regions. Further, the large signal yield and the fast response time should allow bunch-by-bunch measurement of the luminosity at 40 MHz with high accuracy. Four luminosity monitors with two rows of five polycrystalline CdTe detectors each have been fabricated and will be installed at both sides of the low-luminosity interaction points ALICE and LHC-b. A detector housing was specially designed to meet the mechanical constraints in the LHC. A series of elementary CdTe detectors were fabricated and tested, of which 40 were selected for the luminosity monitors. A sensitivity of 104 electrons per minimum ioni...

  18. Measurements of timing resolution of ultra-fast silicon detectors with the SAMPIC waveform digitizer

    Energy Technology Data Exchange (ETDEWEB)

    Breton, D. [CNRS/IN2P3/LAL Orsay, Université Paris-Saclay, F-91898 Orsay (France); De Cacqueray, V.; Delagnes, E. [IRFU, CEA, Université Paris-Saclay, F-91191 Gif-sur-Yvette (France); Grabas, H. [Santa Cruz Institute for Particle Physics UC Santa Cruz, CA 95064 (United States); Maalmi, J. [CNRS/IN2P3/LAL Orsay, Université Paris-Saclay, F-91898 Orsay (France); Minafra, N. [Dipartimento Interateneo di Fisica di Bari, Bari (Italy); CERN, Geneva (Switzerland); Royon, C. [University of Kansas, Lawrence (United States); Saimpert, M., E-mail: matthias.saimpert@cern.ch [IRFU, CEA, Université Paris-Saclay, F-91191 Gif-sur-Yvette (France)

    2016-11-01

    The SAMpler for PICosecond time (SAMPIC) chip has been designed by a collaboration including CEA/IRFU/SEDI, Saclay and CNRS/LAL/SERDI, Orsay. It benefits from both the quick response of a time to digital converter and the versatility of a waveform digitizer to perform accurate timing measurements. Thanks to the sampled signals, smart algorithms making best use of the pulse shape can be used to improve time resolution. A software framework has been developed to analyse the SAMPIC output data and extract timing information by using either a constant fraction discriminator or a fast cross-correlation algorithm. SAMPIC timing capabilities together with the software framework have been tested using pulses generated by a signal generator or by a silicon detector illuminated by a pulsed infrared laser. Under these ideal experimental conditions, the SAMPIC chip has proven to be capable of timing resolutions down to 4 ps with synthesized signals and 40 ps with silicon detector signals.

  19. Performance of silicon pad detectors after mixed irradiations with neutrons and fast charged hadrons

    Energy Technology Data Exchange (ETDEWEB)

    Kramberger, G. [Jozef Stefan Institute, Department of Physics, University of Ljubljana, Jamova 39, SI-1000 Ljubljana (Slovenia)], E-mail: Gregor.Kramberger@ijs.si; Cindro, V.; Dolenc, I.; Mandic, I.; Mikuz, M.; Zavrtanik, M. [Jozef Stefan Institute, Department of Physics, University of Ljubljana, Jamova 39, SI-1000 Ljubljana (Slovenia)

    2009-10-11

    A large set of silicon pad detectors produced on MCz and FZ wafer of p- and n-type was irradiated in two steps, first by fast charged hadrons followed by reactor neutrons. In this way the irradiations resemble the real irradiation fields at LHC. After irradiations controlled annealing started in steps during which the evolution of full depletion voltage, leakage current and charge collection efficiency was monitored. The damage introduced by different irradiation particles was found to be additive. The most striking consequence of that is a decrease of the full depletion voltage for n-type MCz detectors after additional neutron irradiation. This confirms that effective donors introduced by charged hadron irradiation are compensated by acceptors from neutron irradiation.

  20. Performance of silicon pad detectors after mixed irradiations with neutrons and fast charged hadrons

    International Nuclear Information System (INIS)

    Kramberger, G.; Cindro, V.; Dolenc, I.; Mandic, I.; Mikuz, M.; Zavrtanik, M.

    2009-01-01

    A large set of silicon pad detectors produced on MCz and FZ wafer of p- and n-type was irradiated in two steps, first by fast charged hadrons followed by reactor neutrons. In this way the irradiations resemble the real irradiation fields at LHC. After irradiations controlled annealing started in steps during which the evolution of full depletion voltage, leakage current and charge collection efficiency was monitored. The damage introduced by different irradiation particles was found to be additive. The most striking consequence of that is a decrease of the full depletion voltage for n-type MCz detectors after additional neutron irradiation. This confirms that effective donors introduced by charged hadron irradiation are compensated by acceptors from neutron irradiation.

  1. Measurements of timing resolution of ultra-fast silicon detectors with the SAMPIC WTDC

    CERN Document Server

    Breton, Dominique

    2016-11-01

    The SAMpler for PICosecond time (SAMPIC) chip has been designed by a collaboration including CEA/IRFU/SEDI, Saclay and CNRS/LAL/SERDI, Orsay. It benefits from both the quick response of a time to digital converter (TDC) and the versatility of a waveform digitizer to perform accurate timing measurements. Thanks to the sampled signals, smart algorithms making best use of the pulse shape can be used to maximize time resolution. A software framework has been developed to analyse the SAMPIC output data and extract timing information by using either a constant fraction discriminator or a fast cross-correlation algorithm. SAMPIC timing capabilities together with the software framework have been tested using Gaussian signals generated by a signal generator or by silicon detectors pulsed with an infra-red laser. Under these ideal experimental conditions, the SAMPIC chip has proven to be capable of timing resolutions down to 4 (40) ps with synthesized (silicon detector) signals.

  2. Response of reverse convection to fast IMF transitions

    DEFF Research Database (Denmark)

    Taguchi, S.; Tawara, A.; Hairston, M. R.

    2015-01-01

    that variations of the ground magnetic perturbations were produced by the transition from clockwise plasma circulation to the anticlockwise circulation over the polar cap. A simple calculation based on the Biot-Savart law shows that the near-noon transition state is consistent with the approach of a new...

  3. Cryogenic particle detectors with superconducting phase transition thermometers

    International Nuclear Information System (INIS)

    Ferger, P.; Colling, P.; Bucci, C.; Nucciotti, A.; Buehler, M.; Cooper, S.; Feilitzsch, F. v.; Forster, G.; Gabutti, A.; Hoehne, J.; Igalson, J.; Kellner, E.; Loidl, M.; Meier, O.; Nagel, U.; Proebst, F.; Rulofs, A.; Schanda, U.; Seidel, W.; Sisti, M.; Stodolsky, L.; Stolovich, A.; Zerle, L.

    1996-01-01

    A tungsten superconducting phase transition thermometer on a 32 g sapphire crystal has given an energy resolution of 100 eV (FWHM) for 1.5 keV X-rays, increasing to 440 eV at 14 keV. A possibility to obtain similar resolution in much larger crystals by using Al films as phonon collectors is presented. (orig.)

  4. Fast reconstruction of trajectories of charged muons recorded by the MUCH detector in the CBM experiment

    International Nuclear Information System (INIS)

    Ablyazimov, T.O.; Ivanov, V.V.

    2017-01-01

    The CBM experiment is currently being developed in GSI (Darmstadt, Germany) at the FAIR accelerator complex by an international collaboration including JINR. One of the main goals of the experiment is a research of charmonium production process in nucleus-nucleus collisions at high energies. The registration of such decays as J/ψ → μ"+μ"− is planned to be carried out in real time. The current paper presents an algorithm suitable for fast reconstruction of trajectories of charged muons from J/ψ decays recorded by the MUCH detector. [ru

  5. Ultra-fast HPM detectors improve NAD(P)H FLIM

    Science.gov (United States)

    Becker, Wolfgang; Wetzker, Cornelia; Benda, Aleš

    2018-02-01

    Metabolic imaging by NAD(P)H FLIM requires the decay functions in the individual pixels to be resolved into the decay components of bound and unbound NAD(P)H. Metabolic information is contained in the lifetime and relative amplitudes of the components. The separation of the decay components and the accuracy of the amplitudes and lifetimes improves substantially by using ultra-fast HPM-100-06 and HPM-100-07 hybrid detectors. The IRF width in combination with the Becker & Hickl SPC-150N and SPC-150NX TCSPC modules is less than 20 ps. An IRF this fast does not interfere with the fluorescence decay. The usual deconvolution process in the data analysis then virtually becomes a simple curve fitting, and the parameters of the NAD(P)H decay components are obtained at unprecedented accuracy.

  6. Recent progress of fast-ion loss detector project in Asian fusion experiments

    International Nuclear Information System (INIS)

    Isobe, Mitsutaka; Zhang Yipo; Kim, Jun-Young

    2013-01-01

    The A3 foresight program is accelerating close collaboration for fast-ion diagnostics development between Asian three countries. A recent big step in our activities is that the operation of fast-ion loss detector (FILD) on HL-2A has begun lately. The localized bright spot appeared on the scintillator screen while a high-energy neutral beam was tangentially co-injected. The design of FILD system on EAST is steadily ongoing. The diagnostics port available for our purpose was decided in March, 2013. For KSTAR, the FILD is working successfully. In order to understand observed beam-ion loss signals while the RMP coils are turned on, the LORBIT code has been improved recently to treat non-axisymmetric perturbed field due to RMP coils and discreteness of TF coils. (author)

  7. Nuclear Thermal Propulsion (NTP): A Proven, Growth Technology for Fast Transit Human Missions to Mars

    Science.gov (United States)

    Borowski, Stanley K.; McCurdy, David R.; Packard, Thomas W.

    2014-01-01

    The "fast conjunction" long surface stay mission option was selected for NASA's recent Mars Design Reference Architecture (DRA) 5.0 study because it provided adequate time at Mars (approx. 540 days) for the crew to explore the planet's geological diversity while also reducing the "1-way" transit times to and from Mars to approx. 6 months. Short transit times are desirable in order to reduce the debilitating physiological effects on the human body that can result from prolonged exposure to the zero-gravity (0-gE) and radiation environments of space. Recent measurements from the RAD detector attached to the Curiosity rover indicate that astronauts would receive a radiation dose of approx. 0.66 Sv (approx. 66 rem)-the limiting value established by NASA-during their 1-year journey in deep space. Proven nuclear thermal rocket (NTR) technology, with its high thrust and high specific impulse (Isp approx. 900 s), can cut 1-way transit times by as much as 50 percent by increasing the propellant capacity of the Mars transfer vehicle (MTV). No large technology scale-ups in engine size are required for these short transit missions either since the smallest engine tested during the Rover program-the 25 klbf "Pewee" engine is sufficient when used in a clustered arrangement of three to four engines. The "Copernicus" crewed MTV developed for DRA 5.0 is a 0-gE design consisting of three basic components: (1) the NTP stage (NTPS); (2) the crewed payload element; and (3) an integrated "saddle truss" and LH2 propellant drop tank assembly that connects the two elements. With a propellant capacity of approx. 190 t, Copernicus can support 1-way transit times ranging from approx. 150 to 220 days over the 15-year synodic cycle. The paper examines the impact on vehicle design of decreasing transit times for the 2033 mission opportunity. With a fourth "upgraded" SLS/HLV launch, an "in-line" LH2 tank element can be added to Copernicus allowing 1-way transit times of 130 days. To achieve 100

  8. Test beam performance of a tracking TRD [Transition Radiation Detector] prototype

    International Nuclear Information System (INIS)

    Shank, J.T.; Whitaker, J.S.; Polychronakos, V.A.; Radeka, V.; Stephani, D.; Beker, H.; Bock, R.K.; Botlo, M.; Fabjan, C.W.; Pfennig, J.; Price, M.J.; Willis, W.J.; Akesson, T.; Chernyatin, V.; Dolgoshein, B.; Nevsky, P.; Potekhin, M.; Romanjuk, A.; Sosnovtsev, V.; Gavrilenko, I.; Muravjev, S.; Shmeleva, A.

    1990-01-01

    A Tracking Transition Radiation Detector prototype has been constructed and tested. It consists of 240 straw tubes, 4 mm in diameter, imbedded in a polyethylene block acting as the radiator. Its performance as an electron identifier as well as a tracking device for minimum ionizing particles has been determined. 2 refs., 6 figs

  9. Detecting part of the transition radiation detector for the GINES installation at UNK

    International Nuclear Information System (INIS)

    Shikhliarov, K.K.; Gavalian, V.G.; Aginian, M.A.

    1995-01-01

    The detecting part of an X-ray transition radiation detector based on thin-walled mylar straws is considered in this paper. The performance of xenon-filled straws in the self-quenching mode is studied in detail. The measurements have been carried out both with radioactive sources and under the electron beam of the Yerevan synchrotron. (orig.)

  10. New developments on transition radiation detectors using superconducting granules

    International Nuclear Information System (INIS)

    Yuan, L.C.L.

    1977-01-01

    By raising slightly either the temperature or the magnetic field to above that of the critical temperature or the critical magnetic field, the type I superconducting granules would still remain in the superconducting state which becomes a metastable state and is called the superheated superconducting state. If a relativistic charged particle incident on such a granule which is located in a colloidal suspension has imported to it an energy that is above the threshold energy (for state flipping) of the granule then it would flip to the normal state. The threshold energy of a granule is a function of the square of its radius, whereas the energy loss of a charged particle due to ionization is linearly proportional to the radius. The size of the granule can be pre-determined to be such that its threshold energy is slightly above the ionization loss of a relativistic charged particle. Then the traversal of the charged particle through such a granule would not affect the superconducting state of the granule unless a transition x-ray radiation is emitted at the surface of the granule by the traversing particle and the x-ray transition radiation is immediately absorbed either in total or partially by the metallic granule causing it to flip to the normal state. The total intensity of the x-ray transition radiation is linearly proportional to the Lorentz factor γ of the traversing particle, and the number of granules flipped would also be a measure of γ. Three methods for detecting the flipping of granules from the superconducting state to the normal state are described. They include the frequency measuring method, the SQUID method, and the pulse method with low noise amplifier system

  11. Beam test results of a 16 ps timing system based on ultra-fast silicon detectors

    Energy Technology Data Exchange (ETDEWEB)

    Cartiglia, N., E-mail: cartiglia@to.infn.it [INFN, Torino (Italy); Staiano, A.; Sola, V. [INFN, Torino (Italy); Arcidiacono, R. [INFN, Torino (Italy); Università del Piemonte Orientale (Italy); Cirio, R.; Cenna, F.; Ferrero, M.; Monaco, V.; Mulargia, R.; Obertino, M.; Ravera, F.; Sacchi, R. [INFN, Torino (Italy); Università di Torino, Torino (Italy); Bellora, A.; Durando, S. [Università di Torino, Torino (Italy); Mandurrino, M. [Politecnico di Torino, Torino (Italy); Minafra, N. [University of Kansas, KS (United States); Fadeyev, V.; Freeman, P.; Galloway, Z.; Gkougkousis, E. [SCIPP, University of California Santa Cruz, CA 95064 (United States); and others

    2017-04-01

    In this paper we report on the timing resolution obtained in a beam test with pions of 180 GeV/c momentum at CERN for the first production of 45 µm thick Ultra-Fast Silicon Detectors (UFSD). UFSD are based on the Low-Gain Avalanche Detector (LGAD) design, employing n-on-p silicon sensors with internal charge multiplication due to the presence of a thin, low-resistivity diffusion layer below the junction. The UFSD used in this test had a pad area of 1.7 mm{sup 2}. The gain was measured to vary between 5 and 70 depending on the sensor bias voltage. The experimental setup included three UFSD and a fast trigger consisting of a quartz bar readout by a SiPM. The timing resolution was determined by doing Gaussian fits to the time-of-flight of the particles between one or more UFSD and the trigger counter. For a single UFSD the resolution was measured to be 34 ps for a bias voltage of 200 V, and 27 ps for a bias voltage of 230 V. For the combination of 3 UFSD the timing resolution was 20 ps for a bias voltage of 200 V, and 16 ps for a bias voltage of 230 V.

  12. Fast CMOS binary front-end for silicon strip detectors at LHC experiments

    CERN Document Server

    Kaplon, Jan

    2004-01-01

    We present the design and the test results of a front-end circuit developed in a 0.25 mu m CMOS technology. The aim of this work is to study the performance of a deep submicron process in applications for fast binary front-end for silicon strip detectors. The channel comprises a fast transimpedance preamplifier working with an active feedback loop, two stages of the amplifier-integrator circuits providing 22 ns peaking time and two-stage differential discriminator. Particular effort has been made to minimize the current and the power consumption of the preamplifier, while keeping the required noise and timing performance. For a detector capacitance of 20 pF noise below 1500 e/sup -/ ENC has been achieved for 300 mu A bias current in the input transistor, which is comparable with levels achieved in the past for a front-end using bipolar input transistor. The total supply current of the front-end is 600 mu A and the power dissipation is 1.5 mW per channel. The offset spread of the comparator is below 3 mV rms.

  13. Fast neutron dosimetry using CR-39 track detectors with polyethylene as radiator

    International Nuclear Information System (INIS)

    Castillo, F.; Espinosa, G.; Golzarri, J.I.; Osorio, D.; Rangel, J.; Reyes, P.G.; Herrera, J.J.E.

    2013-01-01

    The chemical etching parameters (etching time, temperature, normality of etchant, etc.) for the use of CR-39 (allyl diglycol carbonate – Lantrack ® ) as a fast neutron dosimeter have been optimized. The CR-39 chips, placed under a 1.5 mm polyethylene radiator, were exposed for calibration to an 241 Am-Be source at different time intervals for a given neutron fluence. After several chemical etching processes of the detectors with different conditions, the optimum characteristics for the chemical etching were found at 6N KOH solution, 60 ± 1 °C, for 12 h. An accurate relationship between the dose and fluence calculations was obtained as a function of the track density. - Highlights: ► Optimum etching time for fast neutron irradiated CR-39 track detectors is found. ► Relationship between dose and fluence obtained as a function of the track density. ► Results are consistent with those reported elsewhere, and extend the dose range

  14. Commissioning of the IDS Neutron Detector and $\\beta$-decay fast-timing studies at IDS

    CERN Document Server

    Piersa, Monika

    2016-01-01

    The following report describes my scientific activities performed during the Summer Student Programme at ISOLDE. The main part of my project was focused on commissioning the neutron detector dedicated to nuclear decay studies at ISOLDE Decay Station (IDS). I have participated in all the steps needed to make it operational for the IS609 experiment. In the testing phase, we obtained expected detector response and calibrations confirmed its successful commissioning. The detector was mounted in the desired geometry at IDS and used in measurements of the beta-delayed neutron emission of $^8$He. After completing aforementioned part of my project, I became familiar with the fast-timing method. This technique was applied at IDS in the IS610 experiment performed in June 2016 to explore the structure of neutron-rich $^{130-134}$Sn nuclei. Since the main part of my PhD studies will be the analysis of data collected in this experiment, the second part of my project was dedicated to acquiring knowledge about technical de...

  15. 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.

  16. Recent developments and applications of fast position-sensitive gas detectors

    International Nuclear Information System (INIS)

    Sauli, Fabio

    1999-01-01

    The introduction, 30 years ago, of the multiwire proportional chamber initiated a very active and fruitful period of development of fast gas detectors. Performing position-sensitive devices have been perfected, for the needs of elementary particle physics and for applications in medical diagnostics, biology, material analysis. The high rate performance of wire counters, limited by positive ions accumulation, was largely improved with the introduction of the micro-strip gas chamber, capable of achieving position accuracies of few tens of microns at radiation fluxes exceeding 1 MHz/mm 2 . The micro-strip chamber properties have been extensively studied in view of large scale use in high luminosity experiments; some interesting applications in other fields will be described here. Originally conceived as a gain booster to solve reliability problems met with micro-strips, the gas electron multiplier was invented about a year and a half ago. Progress made with high gain models is leading to a new concept in gas detectors, powerful yet cheap and reliable. Possible developments and applications will be discussed: large area position-sensitive photo detectors and X-ray imagers, including devices with non-planar geometry suited to spectrometers and crystal diffraction studies

  17. Measurements of fast deuterons from plasma accelerator by means of PM-355 track detectors

    Energy Technology Data Exchange (ETDEWEB)

    Skladnik-Sadowska, E. [Andrzej Soltan Institute for Nuclear Studies (IPJ), 05-400 Otwock-Swierk (Poland); Malinowski, K., E-mail: k.malinowski@ipj.gov.p [Andrzej Soltan Institute for Nuclear Studies (IPJ), 05-400 Otwock-Swierk (Poland); Sadowski, M.J.; Czaus, K. [Andrzej Soltan Institute for Nuclear Studies (IPJ), 05-400 Otwock-Swierk (Poland)

    2009-10-15

    This paper reports on studies of fast ions (mostly deuterons) emitted from an RPI (Rod-Plasma-Injector) plasma accelerator. The first aim was the verification of applicability of PM-355 track detectors for dosimetry of lower-energy (<200 KeV) deuterons. The second aim was information about energy spectra of deuterons from RPI-IBIS device in different operational modes. Mass- and energy spectra of ions were investigated with a Thomson-analyzer and PM-355 detectors. On the recorded deuteron-parabolas we chose points, and from numbers of tracks we determined the deuteron energy distribution. In the slow-mode the energy distribution peak was observed at about 40 keV, while the maximum energy amounted to about 150 keV. Those measurements confirmed an influence of the initial gas-conditions on energy distributions of the deuteron streams. The results are of importance for plasma-physics and applications. Another result was the confirmation that PM-355 detectors might be used for accurate measurements of low-energy (<200 keV) deuterons.

  18. Detector-device-independent quantum key distribution: Security analysis and fast implementation

    International Nuclear Information System (INIS)

    Boaron, Alberto; Korzh, Boris; Boso, Gianluca; Martin, Anthony; Zbinden, Hugo; Houlmann, Raphael; Lim, Charles Ci Wen

    2016-01-01

    One of the most pressing issues in quantum key distribution (QKD) is the problem of detector side-channel attacks. To overcome this problem, researchers proposed an elegant “time-reversal” QKD protocol called measurement-device-independent QKD (MDI-QKD), which is based on time-reversed entanglement swapping. However, MDI-QKD is more challenging to implement than standard point-to-point QKD. Recently, an intermediary QKD protocol called detector-device-independent QKD (DDI-QKD) has been proposed to overcome the drawbacks of MDI-QKD, with the hope that it would eventually lead to a more efficient detector side-channel-free QKD system. Here, we analyze the security of DDI-QKD and elucidate its security assumptions. We find that DDI-QKD is not equivalent to MDI-QKD, but its security can be demonstrated with reasonable assumptions. On the more practical side, we consider the feasibility of DDI-QKD and present a fast experimental demonstration (clocked at 625 MHz), capable of secret key exchange up to more than 90 km.

  19. Development of an integrated four-channel fast avalanche-photodiode detector system with nanosecond time resolution

    Science.gov (United States)

    Li, Zhenjie; Li, Qiuju; Chang, Jinfan; Ma, Yichao; Liu, Peng; Wang, Zheng; Hu, Michael Y.; Zhao, Jiyong; Alp, E. E.; Xu, Wei; Tao, Ye; Wu, Chaoqun; Zhou, Yangfan

    2017-10-01

    A four-channel nanosecond time-resolved avalanche-photodiode (APD) detector system is developed at Beijing Synchrotron Radiation. It uses a single module for signal processing and readout. This integrated system provides better reliability and flexibility for custom improvement. The detector system consists of three parts: (i) four APD sensors, (ii) four fast preamplifiers and (iii) a time-digital-converter (TDC) readout electronics. The C30703FH silicon APD chips fabricated by Excelitas are used as the sensors of the detectors. It has an effective light-sensitive area of 10 × 10 mm2 and an absorption layer thickness of 110 μm. A fast preamplifier with a gain of 59 dB and bandwidth of 2 GHz is designed to readout of the weak signal from the C30703FH APD. The TDC is realized by a Spartan-6 field-programmable-gate-array (FPGA) with multiphase method in a resolution of 1ns. The arrival time of all scattering events between two start triggers can be recorded by the TDC. The detector has been used for nuclear resonant scattering study at both Advanced Photon Source and also at Beijing Synchrotron Radiation Facility. For the X-ray energy of 14.4 keV, the time resolution, the full width of half maximum (FWHM) of the detector (APD sensor + fast amplifier) is 0.86 ns, and the whole detector system (APD sensors + fast amplifiers + TDC readout electronics) achieves a time resolution of 1.4 ns.

  20. Studies on the prototype of the transition-radiation detector for the Zeus experiment

    International Nuclear Information System (INIS)

    Munde, A.

    1991-04-01

    The Zeus detector is currently being built for HERA at Hamburg. One part of the inner detector is the transition radiation detector (TRD). It will identify single electrons inside hadronic jets of deep inelastic ep-collisions. To test the chamber performance and to improve mechanical tools, a prototype of the smallest detector modul (TRD-1) was built. The gasgain of this prototype was measured under several high voltage conditions. The gasgain is about 1.5x10 3 up to 8x10 3 in Argon/Methane 90/10. To test the function of this prototype, the test beam facility at the Bonn 2.5 GeV electron synchrotron was used. The same relative amplification was measured by comparing the beam results with those obtained with a Fe 55 -source. (orig.) [de

  1. Fast Track Finding in the ILC's Silicon Detector, SiD01

    International Nuclear Information System (INIS)

    Baker, David E.

    2007-01-01

    A fast track finder is presented which, unlike its more efficient, more computationally costly O(n3) time counterparts, tracks particles in O(n) time (for n being the number of hits). Developed as a tool for processing data from the ILC's proposed SiD detector, development of this fast track finder began with that proposed by Pablo Yepes in 1996 and adjusted to accommodate the changes in geometry of the SiD detector. First, space within the detector is voxellated, with hits assigned to voxels according to their r, φ, and η coordinates. A hit on the outermost layer is selected, and a 'sample space' is built from the hits in the selected hit's surrounding voxels. The hit in the sample space with the smallest distance to the first is then selected, and the sample space recalculated for this hit. This process continues until the list of hits becomes large enough, at which point the helical circle in the x, y plane is conformally mapped to a line in the x', y' plane, and hits are chosen from the sample spaces of the previous fit by selecting the hits which fit a line to the previously selected points with the smallest χ 2 . Track finding terminates when the innermost layer has been reached or no hit in the sample space fits those previously selected to an acceptable χ 2 . Again, a hit on the outermost layer is selected and the process repeats until no assignable hits remain. The algorithm proved to be very efficient on artificial diagnostic events, such as one hundred muons scattered at momenta of 1 GeV/c to 10 GeV/c. Unfortunately, when tracking simulated events corresponding to actual physics, the track finder's efficiency decreased drastically (mostly due to signal noise), though future data cleaning programs could noticeably increase its efficiency on these events

  2. Fast neutron detection at near-core location of a research reactor with a SiC detector

    Science.gov (United States)

    Wang, Lei; Jarrell, Josh; Xue, Sha; Tan, Chuting; Blue, Thomas; Cao, Lei R.

    2018-04-01

    The measurable charged-particle produced from the fast neutron interactions with the Si and C nucleuses can make a wide bandgap silicon carbide (SiC) sensor intrinsically sensitive to neutrons. The 4H-SiC Schottky detectors have been fabricated and tested at up to 500 °C, presenting only a slightly degraded energy resolution. The response spectrum of the SiC detectors were also obtained by exposing the detectors to external neutron beam irradiation and at a near-core location where gamma-ray field is intense. The fast neutron flux of these two locations are ∼ 4 . 8 × 104cm-2 ṡs-1 and ∼ 2 . 2 × 107cm-2 ṡs-1, respectively. At the external beam location, a Si detector was irradiated side-by-side with SiC detector to disjoin the neutron response from Si atoms. The contribution of gamma ray, neutron scattering, and charged-particles producing reactions in the SiC was discussed. The fast neutron detection efficiencies were determined to be 6 . 43 × 10-4 for the external fast neutron beam irradiation and 6 . 13 × 10-6 for the near-core fast neutron irradiation.

  3. LHCb siliicon detectors: the Run 1 to Run 2 transition and first experience of Run 2

    CERN Document Server

    Rinnert, Kurt

    2015-01-01

    LHCb is a dedicated experiment to study New Physics in the decays of heavy hadrons at the Large Hadron Collider (LHC) at CERN. The detector includes a high precision tracking system consisting of a silicon-strip vertex detector (VELO) surrounding the pp interaction region, a large- area silicon-strip detector located upstream of a dipole magnet (TT), and three stations of silicon- strip detectors (IT) and straw drift tubes placed downstream (OT). The operational transition of the silicon detectors VELO, TT and IT from LHC Run 1 to Run 2 and first Run 2 experiences will be presented. During the long shutdown of the LHC the silicon detectors have been maintained in a safe state and operated regularly to validate changes in the control infrastructure, new operational procedures, updates to the alarm systems and monitoring software. In addition, there have been some infrastructure related challenges due to maintenance performed in the vicinity of the silicon detectors that will be discussed. The LHCb silicon dete...

  4. Probing Photoinduced Structural Phase Transitions by Fast or Ultra-Fast Time-Resolved X-Ray Diffraction

    Science.gov (United States)

    Cailleau, Hervé Collet, Eric; Buron-Le Cointe, Marylise; Lemée-Cailleau, Marie-Hélène Koshihara, Shin-Ya

    A new frontier in the field of structural science is the emergence of the fast and ultra-fast X-ray science. Recent developments in time-resolved X-ray diffraction promise direct access to the dynamics of electronic, atomic and molecular motions in condensed matter triggered by a pulsed laser irradiation, i.e. to record "molecular movies" during the transformation of matter initiated by light pulse. These laser pump and X-ray probe techniques now provide an outstanding opportunity for the direct observation of a photoinduced structural phase transition as it takes place. The use of X-ray short-pulse of about 100ps around third-generation synchrotron sources allows structural investigations of fast photoinduced processes. Other new X-ray sources, such as laser-produced plasma ones, generate ultra-short pulses down to 100 fs. This opens the way to femtosecond X-ray crystallography, but with rather low X-ray intensities and more limited experimental possibilities at present. However this new ultra-fast science rapidly progresses around these sources and new large-scale projects exist. It is the aim of this contribution to overview the state of art and the perspectives of fast and ultra-fast X-ray scattering techniques to study photoinduced phase transitions (here, the word ultra-fast is used for sub-picosecond time resolution). In particular we would like to largely present the contribution of crystallographic methods in comparison with optical methods, such as pump-probe reflectivity measurements, the reader being not necessary familiar with X-ray scattering. Thus we want to present which type of physical information can be obtained from the positions of the Bragg peaks, their intensity and their shape, as well as from the diffuse scattering beyond Bragg peaks. An important physical feature is to take into consideration the difference in nature between a photoinduced phase transition and conventional homogeneous photoinduced chemical or biochemical processes where

  5. A fast CCD detector for charge exchange recombination spectroscopy on the DIII-D tokamak

    International Nuclear Information System (INIS)

    Thomas, D.M.; Burrell, K.H.; Groebner, R.J.; Gohil, P.

    1996-05-01

    Charge Exchange Recombination (CER) spectroscopy has become a standard diagnostic for tokamaks. CER measurements have been used to determine spatially and temporally resolved ion temperature, toroidal and poloidal ion rotation speed, impurity density and radial electric field. Knowledge of the spatial profile and temporal evolution of the electric field shear in the plasma edge is crucial to understanding the physics of the L to H transition. High speed CER measurements are also valuable for Edge Localized Mode (ELM) studies. Since the 0.52 ms minimum time resolution of our present system is barely adequate to study the time evolution of these phenomena, we have developed a new CCD detector system with about a factor of two better time resolution. In addition, our existing system detects sufficient photons to utilize the shortest time resolution only under exceptional conditions. The new CCD detector has a quantum efficiency of about 0.65, which is a factor of 7 better than our previous image intensifier-silicon photodiode detector systems. We have also equipped the new system with spectrometers of lower f/number. This combination should allow more routine operation at the minimum integration time, as well as improving data quality for measurements in the divertor-relevant region outside of the separatrix. Construction details, benchmark data and initial tokamak measurements for the new system will be presented

  6. A fast integrated readout system for a cathode pad photon detector

    Energy Technology Data Exchange (ETDEWEB)

    French, M. (Rutherford Appleton Lab., Chilton (United Kingdom)); Lovell, M. (Rutherford Appleton Lab., Chilton (United Kingdom)); Chesi, E. (CERN, ECP Div., Geneva (Switzerland)); Racz, A. (CERN, ECP Div., Geneva (Switzerland)); Seguinot, J. (Coll. de France, Paris (France)); Ypsilantis, T. (Coll. de France, Paris (France)); Arnold, R. (CRN, Louis Pasteur Univ., Strasbourg (France)); Guyonnet, J.L. (CRN, Louis Pasteur Univ., Strasbourg (France)); Egger, J. (Paul Scherrer Inst., Villigen (Switzerland)); Gabathuler, K. (Paul Scherrer Inst., Villigen (Switzerland))

    1994-04-01

    A fast integrated electronic chain is presented to read out the cathode pad array of a multiwire photon detector for a fast RICH counter. Two VLSI circuits have been designed and produced. An analog eight channel, low noise, fast, bipolar, current preamplifier and discriminator chip serves as front-end electronics. It has an rms equivalent noise current of 10 nA (2000 e[sup -]), 50 MHz bandwidth with 10 mW of power consumption per channel. Two analogue chips are coupled to a digital 16 channels CMOS readout chip, operating at 20 MHz, that provides a pipelined delay of 1.3 [mu]s and zero suppression with a power consumption of about 6 mW per channel. Readout of a 4000 pad sector requires 3-4 [mu]s depending on the number of hit pads. The full RICH counter is made up of many of such sectors (the prototype has three fully equipped sectors), read out in parallel. The minimum time to separate successive hits on the same pad is about 70 ns. The time skew of the full chain is about 15 ns. (orig.)

  7. A fast preamplifier concept for SiPM-based time-of-flight PET detectors

    Energy Technology Data Exchange (ETDEWEB)

    Huizenga, J., E-mail: j.huizenga@tudelft.nl [Delft University of Technology, Radiation Detection and Medical Imaging, Mekelweg 15, 2629 JB Delft (Netherlands); Seifert, S. [Delft University of Technology, Radiation Detection and Medical Imaging, Mekelweg 15, 2629 JB Delft (Netherlands); Schreuder, F. [Kernfysisch Versneller Instituut, University of Groningen, Zernikelaan 25, 9747 AA Groningen (Netherlands); Dam, H.T. van [Delft University of Technology, Radiation Detection and Medical Imaging, Mekelweg 15, 2629 JB Delft (Netherlands); Dendooven, P.; Loehner, H.; Vinke, R. [Kernfysisch Versneller Instituut, University of Groningen, Zernikelaan 25, 9747 AA Groningen (Netherlands); Schaart, D.R. [Delft University of Technology, Radiation Detection and Medical Imaging, Mekelweg 15, 2629 JB Delft (Netherlands)

    2012-12-11

    Silicon photomultipliers (SiPMs) offer high gain and fast response to light, making them interesting for fast timing applications such as time-of-flight (TOF) PET. To fully exploit the potential of these photosensors, dedicated preamplifiers that do not deteriorate the rise time and signal-to-noise ratio are crucial. Challenges include the high sensor capacitance, typically >300 pF for a 3 mm Multiplication-Sign 3 mm SiPM sensor, as well as oscillation issues. Here we present a preamplifier concept based on low noise, high speed transistors, designed for optimum timing performance. The input stage consists of a transimpedance common-base amplifier with a very low input impedance even at high frequencies, which assures a good linearity and avoids that the high detector capacitance affects the amplifier bandwidth. The amplifier has a fast timing output as well as a 'slow' energy output optimized for determining the total charge content of the pulse. The rise time of the amplifier is about 300 ps. The measured coincidence resolving time (CRT) for 511 keV photon pairs using the amplifiers in combination with 3 mm Multiplication-Sign 3 mm SiPMs (Hamamatsu MPPC-S10362-33-050C) coupled to 3 mm Multiplication-Sign 3 mm Multiplication-Sign 5 mm LaBr{sub 3}:Ce and LYSO:Ce crystals equals 95 ps FWHM and 138 ps FWHM, respectively.

  8. A fast preamplifier concept for SiPM-based time-of-flight PET detectors

    International Nuclear Information System (INIS)

    Huizenga, J.; Seifert, S.; Schreuder, F.; Dam, H.T. van; Dendooven, P.; Löhner, H.; Vinke, R.; Schaart, D.R.

    2012-01-01

    Silicon photomultipliers (SiPMs) offer high gain and fast response to light, making them interesting for fast timing applications such as time-of-flight (TOF) PET. To fully exploit the potential of these photosensors, dedicated preamplifiers that do not deteriorate the rise time and signal-to-noise ratio are crucial. Challenges include the high sensor capacitance, typically >300 pF for a 3 mm×3 mm SiPM sensor, as well as oscillation issues. Here we present a preamplifier concept based on low noise, high speed transistors, designed for optimum timing performance. The input stage consists of a transimpedance common-base amplifier with a very low input impedance even at high frequencies, which assures a good linearity and avoids that the high detector capacitance affects the amplifier bandwidth. The amplifier has a fast timing output as well as a ‘slow’ energy output optimized for determining the total charge content of the pulse. The rise time of the amplifier is about 300 ps. The measured coincidence resolving time (CRT) for 511 keV photon pairs using the amplifiers in combination with 3 mm×3 mm SiPMs (Hamamatsu MPPC-S10362-33-050C) coupled to 3 mm×3 mm×5 mm LaBr 3 :Ce and LYSO:Ce crystals equals 95 ps FWHM and 138 ps FWHM, respectively.

  9. Weightfield2: A fast simulator for silicon and diamond solid state detector

    Energy Technology Data Exchange (ETDEWEB)

    Cenna, Francesca, E-mail: cenna@to.infn.it [INFN Torino, Via Pietro Giuria 1, Torino (Italy); Cartiglia, N. [INFN Torino, Via Pietro Giuria 1, Torino (Italy); Friedl, M.; Kolbinger, B. [HEPHY Vienna (Austria); Sadrozinski, H.F.-W.; Seiden, A.; Zatserklyaniy, Andriy; Zatserklyaniy, Anton [University of California, Santa Cruz (United States)

    2015-10-01

    We have developed a fast simulation program to study the performance of silicon and diamond detectors, Weightfield2. The program uses GEANT4 libraries to simulate the energy released by an incoming particle in silicon (or diamond), and Ramo's theorem to generate the induced signal current. A graphical interface allows the user to configure many input parameters such as the incident particle, sensor geometry, presence and value of internal gain, doping of silicon sensor and its operating conditions, the values of an external magnetic field, ambient temperature and thermal diffusion. A simplified electronics simulator is also implemented to include the response of an oscilloscope and front-end electronics. The program has been validated by comparing its predictions for minimum ionizing and α particles with measured signals and TCAD simulations, finding very good agreement in both cases.

  10. Fast Detection of Airports on Remote Sensing Images with Single Shot MultiBox Detector

    Science.gov (United States)

    Xia, Fei; Li, HuiZhou

    2018-01-01

    This paper introduces a method for fast airport detection on remote sensing images (RSIs) using Single Shot MultiBox Detector (SSD). To our knowledge, this could be the first study which introduces an end-to-end detection model into airport detection on RSIs. Based on the common low-level features between natural images and RSIs, a convolution neural network trained on large amounts of natural images was transferred to tackle the airport detection problem with limited annotated data. To deal with the specific characteristics of RSIs, some related parameters in the SSD, such as the scales and layers, were modified for more accurate and rapider detection. The experiments show that the proposed method could achieve 83.5% Average Recall at 8 FPS on RSIs with the size of 1024*1024. In contrast to Faster R-CNN, an improvement on AP and speed could be obtained.

  11. Fast neutron spectrometry based on proton detection in CR-39 detector

    Energy Technology Data Exchange (ETDEWEB)

    Dajko, G.; Somogyi, G.

    1986-01-01

    The authors have developed a home-made proton-sensitive CR-39 track detector called MA-ND/p. Using this and the n-p scattering process the performance of a fast neutron spectrometer has been studied by applying two different methods. These are based on track density determinations by using varying radiator thicknesses at constant etching time and by using varying etching times at fixed radiator thickness, respectively. For both methods studied a computer programme is made to calculate the theoretically expected neutron sensitivity as a function of neutron energy. For both methods the neutron sensitivities, expressed in terms of observable etched proton tracks per neutron, are determined experimentally for 3.3 and 14.7 MeV neutron energies. The theoretical and experimental data obtained are compared.

  12. Fast neutron spectrometry based on proton detection in CR-39 detector

    International Nuclear Information System (INIS)

    Dajko, G.; Somogyi, G.

    1986-01-01

    The authors have developed a home-made proton-sensitive CR-39 track detector called MA-ND/p. Using this and the n-p scattering process the performance of a fast neutron spectrometer has been studied by applying two different methods. These are based on track density determinations by using varying radiator thicknesses at constant etching time and by using varying etching times at fixed radiator thickness, respectively. For both methods studied a computer programme is made to calculate the theoretically expected neutron sensitivity as a function of neutron energy. For both methods the neutron sensitivities, expressed in terms of observable etched proton tracks per neutron, are determined experimentally for 3.3 and 14.7 MeV neutron energies. The theoretical and experimental data obtained are compared. (author)

  13. Fast infrared array spectrometer with a thermoelectrically cooled 160-element PbSe detector

    International Nuclear Information System (INIS)

    Ji Jun; Gore, Jay P.; Sivathanu, Yudaya R.; Lim, Jongmook

    2004-01-01

    A fast infrared array spectrometer (FIAS) with a thermoelectrically cooled 160-element PbSe detector was demonstrated using measurements of instantaneous infrared radiation intensities simultaneously over the 1.8-4.9 μm wavelength range at a sampling rate of 390 Hz. A three-point second-degree Lagrange interpolation polynomial was constructed to calibrate the FIAS because of the nonlinear response of the infrared array detector to the incident radiation beam. This calibration method gave excellent measurements of blackbody radiation spectra except for a narrow band at wavelength of 4.3 μm due to absorption by room carbon dioxide, which is one of the two major gas radiation peaks (2.7 and 4.3 μm) from the lean premixed hydrocarbon/air combustion products in the midinfrared spectrum. Therefore, the absorption coefficient of room carbon dioxide was conveniently measured on site with the blackbody reference source, and was used in the calibration of the FIAS and also in the calculations of the radiation spectra. Blackbody tests showed that this procedure was effective in correcting for the room carbon dioxide absorption in the radiation spectra measured by the FIAS. For an example of its application, the calibrated FIAS was used to measure spectral radiation intensities from three lean premixed laminar flames and a premixed turbulent jet flame for which reference data with a grating spectrometer were available for comparison. The agreement between the FIAS measurements and the reference data was excellent

  14. Trends in hard X-ray fluorescence mapping: environmental applications in the age of fast detectors

    Energy Technology Data Exchange (ETDEWEB)

    Lombi, E.; Donner, E. [University of South Australia, Centre for Environmental Risk Assessment and Remediation, Mawson Lakes, South Australia (Australia); CRC CARE, PO Box 486, Salisbury, South Australia (Australia); Jonge, M.D. de; Paterson, D. [Australian Synchrotron, X-ray Fluorescence Microscopy, 800 Blackburn Road, Clayton, Victoria (Australia); Ryan, C.G. [CSIRO Earth Science and Resource Engineering, Normanby Road, Clayton, Victoria (Australia)

    2011-06-15

    Environmental samples are extremely diverse but share a tendency for heterogeneity and complexity. This heterogeneity poses methodological challenges when investigating biogeochemical processes. In recent years, the development of analytical tools capable of probing element distribution and speciation at the microscale have allowed this challenge to be addressed. Of these available tools, laterally resolved synchrotron techniques such as X-ray fluorescence mapping are key methods for the in situ investigation of micronutrients and inorganic contaminants in environmental samples. This article demonstrates how recent advances in X-ray fluorescence detector technology are bringing new possibilities to environmental research. Fast detectors are helping to circumvent major issues such as X-ray beam damage of hydrated samples, as dwell times during scanning are reduced. They are also helping to reduce temporal beamtime requirements, making particularly time-consuming techniques such as micro X-ray fluorescence ({mu}XRF) tomography increasingly feasible. This article focuses on {mu}XRF mapping of nutrients and metalloids in environmental samples, and suggests that the current divide between mapping and speciation techniques will be increasingly blurred by the development of combined approaches. (orig.)

  15. SPECTRUM WEIGHTED RESPONSES OF SEVERAL DETECTORS IN MIXED FIELDS OF FAST AND THERMAL NEUTRONS

    Directory of Open Access Journals (Sweden)

    SANG IN KIM

    2014-04-01

    Full Text Available The spectrum weighted responses of various detectors were calculated to provide guidance on the proper selection and use of survey instruments on the basis of their energy response characteristics on the neutron fields. To yield the spectrum weighted response, the detector response functions of 17 neutron-measuring devices were numerically folded with each of the produced calibration neutron spectra through the in-house developed software ‘K-SWR’. The detectors’ response functions were taken from the IAEA Technical Reports Series No. 403 (TRS-403. The reference neutron fields of 21 kinds with 2 spectra groups with different proportions of thermal and fast neutrons have been produced using neutrons from the 241Am-Be sources held in a graphite pile, a bare 241Am-Be source, and a DT neutron generator. Fluence-average energy (Eave varied from 3.8 MeV to 16.9 MeV, and the ambient-dose-equivalent rate [H*(10/h] varied from 0.99 to 16.5 mSv/h.

  16. Development of Fast and High Precision CMOS Pixel Sensors for an ILC Vertex Detector

    CERN Document Server

    Hu-Guo, Christine

    2010-01-01

    The development of CMOS pixel sensors with column parallel read-out and integrated zero-suppression has resulted in a full size, nearly 1 Megapixel, prototype with ~100 \\mu s read-out time. Its performances are quite close to the ILD vertex detector specifications, showing that the sensor architecture can presumably be evolved to meet these specifications exactly. Starting from the existing architecture and achieved performances, the paper will expose the details of how the sensor will be evolved in the coming 2-3 years in perspective of the ILD Detector Baseline Document, to be delivered in 2012. Two different devices are foreseen for this objective, one being optimized for the inner layers and their fast read-out requirement, while the other exploits the dimmed background in the outer layers to reduce the power consumption. The sensor evolution relies on a high resistivity epitaxial layer, on the use of an advanced CMOS process and on the combination of column-level ADCs with a pixel array. The paper will p...

  17. Qualification and characterization of electronics of the fast neutron Hodoscope detectors using neutrons from CABRI core

    Science.gov (United States)

    Mirotta, S.; Guillot, J.; Chevalier, V.; Biard, B.

    2018-01-01

    The study of Reactivity Initiated Accidents (RIA) is important to determine up to which limits nuclear fuels can withstand such accidents without clad failure. The CABRI International Program (CIP), conducted by IRSN under an OECD/NEA agreement, has been launched to perform representative RIA Integral Effect Tests (IET) on real irradiated fuel rods in prototypical Pressurized Water Reactors (PWR) conditions. For this purpose, the CABRI experimental pulse reactor, operated by CEA in Cadarache, France, has been strongly renovated, and equipped with a pressurized water loop. The behavior of the test rod, located in that loop in the center of the driver core, is followed in real time during the power transients thanks to the hodoscope, a unique online fuel motion monitoring system, and one of the major distinctive features of CABRI. The hodoscope measures the fast neutrons emitted by the tested rod during the power pulse with a complete set of 153 Fission Chambers and 153 Proton Recoil Counters. During the CABRI facility renovation, the electronic chain of these detectors has been upgraded. In this paper, the performance of the new system is presented describing gain calibration methodology in order to get maximal Signal/Noise ratio for amplification modules, threshold tuning methodology for the discrimination modules (old and new ones), and linear detectors response limit versus different reactor powers for the whole electronic chain.

  18. A transition radiation detector interleaved with low-density targets for the NOE experiment

    CERN Document Server

    Alexandrov, K V; Bernardini, P; Brigida, M; Campana, D; Candela, A M; Caruso, R; Cassese, F; Ceres, A; D'Aquino, B; De Cataldo, G; De Mitri, I; Di Credico, A; Favuzzi, C; Fusco, P; Gargano, F; Giglietto, N; Giordano, F; Grillo, A; Guarino, F; Gustavino, C; Lamanna, E; Lauro, A; Leone, A; Loparco, F; Mancarella, G; Martello, D; Mazziotta, M N; Mikheyev, S P; Mongelli, M; Osteria, G; Palladino, Vittorio; Passeggio, G; Perchiazzi, M; Pontoniere, G; Rainó, A; Rocco, R; Romanucci, E; Rubizzo, U; Sacchetti, A; Scapparone, E; Spinelli, P; Tikhomirov, V; Vaccina, A; Vanzanella, E; Weber, M

    2001-01-01

    The NOE Collaboration has proposed a transition radiation detector (TRD) interleaved with marble targets to tag the electron decay channel of tau leptons produced by nu /sub tau /, eventually originated by nu /sub mu / oscillations in a long base line experiment. A reduced scale TRD detector prototype has been built and exposed to an electron/pion beam at the CERN PS. Discrimination capabilities between electrons and both charged and neutral pions, representing the main source of background for our measurement, have been determined obtaining rejection factors of the order of the tenth of percent for charged pions, and of a few percent for the neutral pion, matching the experiment requirements. The capabilities of this detector to measure the energy released by particles that start showering inside the targets are shown. A momentum resolution sigma /sub p//P

  19. Fast neutron tomography with real-time pulse-shape discrimination in organic scintillation detectors

    Energy Technology Data Exchange (ETDEWEB)

    Joyce, Malcolm J., E-mail: m.joyce@lancaster.ac.uk [Department of Engineering, Lancaster University, Lancaster, Lancashire LA1 4YW (United Kingdom); Agar, Stewart [Department of Engineering, Lancaster University, Lancaster, Lancashire LA1 4YW (United Kingdom); Aspinall, Michael D. [Hybrid Instruments Ltd., Gordon Manley Building, Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YW (United Kingdom); Beaumont, Jonathan S.; Colley, Edmund; Colling, Miriam; Dykes, Joseph; Kardasopoulos, Phoevos; Mitton, Katie [Department of Engineering, Lancaster University, Lancaster, Lancashire LA1 4YW (United Kingdom)

    2016-10-21

    A fast neutron tomography system based on the use of real-time pulse-shape discrimination in 7 organic liquid scintillation detectors is described. The system has been tested with a californium-252 source of dose rate 163 μSv/h at 1 m and neutron emission rate of 1.5×10{sup 7} per second into 4π and a maximum acquisition time of 2 h, to characterize two 100×100×100 mm{sup 3} concrete samples. The first of these was a solid sample and the second has a vertical, cylindrical void. The experimental data, supported by simulations with both Monte Carlo methods and MATLAB®, indicate that the presence of the internal cylindrical void, corners and inhomogeneities in the samples can be discerned. The potential for fast neutron assay of this type with the capability to probe hydrogenous features in large low-Z samples is discussed. Neutron tomography of bulk porous samples is achieved that combines effective penetration not possible with thermal neutrons in the absence of beam hardening.

  20. Fast digital envelope detector based on generalized harmonic wavelet transform for BOTDR performance improvement

    International Nuclear Information System (INIS)

    Yang, Wei; Yang, Yuanhong; Yang, Mingwei

    2014-01-01

    We propose a fast digital envelope detector (DED) based on the generalized harmonic wavelet transform to improve the performance of coherent heterodyne Brillouin optical time domain reflectometry. The proposed DED can obtain undistorted envelopes due to the zero phase-shift ideal bandpass filter (BPF) characteristics of the generalized harmonic wavelet (GHW). Its envelope average ability benefits from the passband designing flexibility of the GHW, and its demodulation speed can be accelerated by using a fast algorithm that only analyses signals of interest within the passband of the GHW with reduced computational complexity. The feasibility and advantage of the proposed DED are verified by simulations and experiments. With an optimized bandwidth, Brillouin frequency shift accuracy improvements of 19.4% and 11.14%, as well as envelope demodulation speed increases of 39.1% and 24.9%, are experimentally attained by the proposed DED over Hilbert transform (HT) and Morlet wavelet transform (MWT) based DEDs, respectively. Spatial resolution by the proposed DED is undegraded, which is identical to the undegraded value by HT-DED with an allpass filter characteristic and better than the degraded value by MWT-DED with a Gaussian BPF characteristic. (paper)

  1. Application of the alanine detector to gamma-ray, X-ray and fast neutron dosimetry

    International Nuclear Information System (INIS)

    Waligorski, M.P.R.; Hansen, J.W.; Byrski, E.

    1987-01-01

    A dosimeter based on alanine has been developed at the INP in Krakow and at Risoe National Laboratory. Due to its near tissue-equivalence and stability of signal, measured using ESR spectrometry at room temperature, this free-radical amino-acid dosimetric system is particularly suitable for measuring X-ray, gamma-ray and fast neutron doses in the range 10-10 5 Gy. The relative effectiveness (with respect to 60 Co γ-rays) of the alanine dosimeter to 250 kVp X-rays and to cyclotron-produced fast neutrons (mean neutron energy 5.6 MeV) is measured to be 0.76± 0.06 and 0.60±0.05, respectively. The suitability of the alanine dosimeter for intercomparison gamma-ray dosimetry is also shown. The estimated absolute difference between 60 Co dosimetry at Risoe National Laboratory and at the Centre of Oncology in Krakow is about 5%, somewhat more than the experimental uncertainty. These results are based on ESR measurements performed in Krakow on about 25% of the exposed detectors. 28 refs., 2 figs., 3 tabs. (author)

  2. Development of the fast and efficient gamma detector using Cherenkov light for TOF-PET

    Science.gov (United States)

    Canot, C.; Alokhina, M.; Abbon, P.; Bard, J. P.; Tauzin, G.; Yvon, D.; Sharyy, V.

    2017-12-01

    In this paper we present two configurations of innovative gamma detectors using Cherenkov light for time-of-flight—Positron Emission Tomography (PET). The first uses heavy crystals as a Cherenkov radiator to develop a demonstrator for a whole body PET scanner with high detection efficiency. We demonstrated a 30% detection efficiency and a 180 ps (FWHM) time resolution, mainly limited by the time transit spread of the photomultiplier. The second configuration uses an innovative liquid, the TriMethyl Bismuth, to develop a high precision brain-scanning PET device with time-of-flight capability. According to Geant4 simulation, we expect to reach a precision of 150 ps (FWHM) and an efficiency of about 25%.

  3. Feasibility study of Self Powered Neutron Detectors in Fast Reactors for detecting local change in neutron flux distribution

    International Nuclear Information System (INIS)

    Jammes, Christian; Filliatre, Philippe; Verma, Vasudha; Hellesen, Carl; Jacobsson Svard, Staffan

    2015-01-01

    Neutron flux monitoring system forms an integral part of the design of a Generation IV sodium cooled fast reactor system. Diverse possibilities of detector systems installation have to be investigated with respect to practicality and feasibility according to the detection parameters. In this paper, we demonstrate the feasibility of using self powered neutron detectors as in-core detectors in fast reactors for detecting local change in neutron flux distribution. We show that the gamma contribution from fission products decay in the fuel and activation of structural materials is very small compared to the fission gammas. Thus, it is possible for the in-core SPND signal to follow changes in local neutron flux as they are proportional to each other. This implies that the signal from an in-core SPND can provide dynamic information on the neutron flux perturbations occurring inside the reactor core. (authors)

  4. Feasibility study of Self Powered Neutron Detectors in Fast Reactors for detecting local change in neutron flux distribution

    Energy Technology Data Exchange (ETDEWEB)

    Jammes, Christian; Filliatre, Philippe [CEA, DEN, DER, Instrumentation Sensors and Dosimetry Laboratory, Cadarache, F-13108 St Paul-Lez-Durance, (France); Verma, Vasudha; Hellesen, Carl; Jacobsson Svard, Staffan [Division of Applied Nuclear Physics, Uppsala University, SE-75120 Uppsala, (Sweden)

    2015-07-01

    Neutron flux monitoring system forms an integral part of the design of a Generation IV sodium cooled fast reactor system. Diverse possibilities of detector systems installation have to be investigated with respect to practicality and feasibility according to the detection parameters. In this paper, we demonstrate the feasibility of using self powered neutron detectors as in-core detectors in fast reactors for detecting local change in neutron flux distribution. We show that the gamma contribution from fission products decay in the fuel and activation of structural materials is very small compared to the fission gammas. Thus, it is possible for the in-core SPND signal to follow changes in local neutron flux as they are proportional to each other. This implies that the signal from an in-core SPND can provide dynamic information on the neutron flux perturbations occurring inside the reactor core. (authors)

  5. A fast neutron spectrometer based on an electrochemically etched CR-39 detector with degrader and front radiator

    International Nuclear Information System (INIS)

    Matiullah; Durrani, S.A.

    1987-01-01

    In addition to having promising applications for the development of a fast-neutron dosemeter, electrochemically etched (ECE) CR-39 detectors also offer the possibility of energy-selective fast-neutron detection. This property stems basically from the fact that, to produce 'sparkable' trails in the polymeric detector subjected to ECE, the charged particle resulting from a neutron interaction must fall within a definite 'energy window'. The lower and upper limits of proton energies that can yield ECE spots in CR-39 have been experimentally determined to be ∼ 50 keV and ∼ 2.2 MeV under our processing conditions. To accomplish our objective, we have developed a technique based on ECE spot-density measurements in CR-39 detectors placed in conjuction with judiciously chosen thicknesses of a polyethylene radiator and a lead degrader. The optimum thicknesses of the radiator and the degrader, for a given neutron energy, are determined by computer calculations. (author)

  6. Scintillator based detector for fast-ion losses induced by magnetohydrodynamic instabilities in the ASDEX upgrade tokamak.

    Science.gov (United States)

    García-Muñoz, M; Fahrbach, H-U; Zohm, H

    2009-05-01

    A scintillator based detector for fast-ion losses has been designed and installed on the ASDEX upgrade (AUG) tokamak [A. Herrmann and O. Gruber, Fusion Sci. Technol. 44, 569 (2003)]. The detector resolves in time the energy and pitch angle of fast-ion losses induced by magnetohydrodynamics (MHD) fluctuations. The use of a novel scintillator material with a very short decay time and high quantum efficiency allows to identify the MHD fluctuations responsible for the ion losses through Fourier analysis. A Faraday cup (secondary scintillator plate) has been embedded behind the scintillator plate for an absolute calibration of the detector. The detector is mounted on a manipulator to vary its radial position with respect to the plasma. A thermocouple on the inner side of the graphite protection enables the safety search for the most adequate radial position. To align the scintillator light pattern with the light detectors a system composed by a lens and a vacuum-compatible halogen lamp has been allocated within the detector head. In this paper, the design of the scintillator probe, as well as the new technique used to analyze the data through spectrograms will be described. A last section is devoted to discuss the diagnosis prospects of this method for ITER [M. Shimada et al., Nucl. Fusion 47, S1 (2007)].

  7. Slow shocks and their transition to fast shocks in the inner solar wind

    International Nuclear Information System (INIS)

    Wang, Y.C.

    1987-01-01

    The jump conditions of MHD shocks may be directly calculated as functions of three upstream conditions: the shock Alfven number based on the normal component of the relative shock speed, the shock angle, and the plasma β value. The shock Alfven number is less than 1 for a slow shock and greater than 1 for a fast shock. A traveling, forward shock can be a slow shock in coronal space, where the Alfven speed is of the order of 1000 km/s. The surface of a forward slow shock has a bow-shaped geometry with its nose facing toward the sun. The decrease in the Alfven speed at increasing heliocentric distance causes the shock Alfven number of a forward slow shock to become greater than 1, and the shock eventually evolves from a slow shock into a fast shock. During the transition the shock system consists of a slow shock, a fast shock, and a rotational discontinuity. They intersect along a closed transition line. As the system moves outward from the sun, the area enclosed by the transition line expands, the fast shock grows stronger, and the slow shock becomes weaker. Eventually, the slow shock diminishes, and the entire shock system evolves into a forward fast shock. copyrightAmerican Geophysical Union 1987

  8. "Joined up" Thinking? Unsupported "Fast-Track" Transitions in the Context of Parental Substance Use

    Science.gov (United States)

    Wilson, Sarah; Cunningham-Burley, Sarah; Bancroft, Angus; Backett-Milburn, Kathryn

    2008-01-01

    Recent policy responses to the risks entailed in "fast-track" school-work transitions have targeted careleavers and young people identified as "not in education, employment or training" (NEET). However, this approach has been criticised as diverting attention away from the fragile circumstances of others who may receive little…

  9. Study of a transition radiation detector for the DO experiment at FNAL

    International Nuclear Information System (INIS)

    Feinstein, F.

    1988-06-01

    The DZero experiment will study proton-antiproton collisions at 1.8 TeV in the center of mass produced at Fermi National Accelerator Laboratory (USA). The main features of the detector are an excellent hermetical calorimeter and a very good identification of muons and electrons. The Transition Radiation Detector contributes to electron/jet discrimination. Transition radiation is emitted when a charge particle crosses the interface between two media of different refraction indices. A N foils radiator produces about N/137 soft X rays when the Lorentz factor gamma of the particle is greater than a threshold of the order of 1000. The radiated energy saturates when gamma goes to infinity. These properties allow to separate electrons from pions until 140 GeV. This study presents the results of a test on a 5 GeV electron and pion beam of a prototype of chamber and of three radiators made of lithium foils, polypropylene foils, and polyethylene fibers. The detector response to pions and electrons is compared to theoretical predictions. Different statistical methods of electron/pion separation are compared on the experimental data. A method has been performed using likelihood functions which obtains a pion rejection greater than 50 for an electron efficiency of 90%. The performances are compared to those of other TRDs [fr

  10. First determination of the e/π separation efficiency of the ZEUS transition radiation detector

    International Nuclear Information System (INIS)

    Mengel, S.

    1995-12-01

    The Transition Radiation Detector of the ZEUS experiment at DESY is one of its main instruments for electron identification. It started to operate partly in 1993 and for the first time with its four modules in 1994. One of its main features is a Time Expansion Chamber to detect the transition radiation of electrons together with the ionisation energy loss of the particle tracks. The first data taken under realistic environmental conditions served as tool to find appropriate running conditions and procedures for data treatment. The main aim however was to show that the detector is sensitive to electrons and to evaluate its rejection power. This analysis describes the on-line and off-line data processing required to exploit the information contained in the raw data. Concepts for detector cross channel calibration and signal recombination are presented. The effect of different running conditions is discussed. To determine the rejection power a data selection was performed extracting electrons and hadrons using all means except the TRD. The response of the TRD to these data samples was compared and a clear sensitivity for electrons was found. Using different likelihood methods values for separation power are derived. The hadron suppression obtained at 90% electron efficiency is - for momenta from 1 to 3 GeV/c - between 27% to 10%, which is already close to the design/test chamber results of 9% to 1.7%. As a projection for close-to-optimum running conditions a hadron suppression from 12% to 2% was obtained. (orig.)

  11. The ALICE Transition Radiation Detector: status and perspectives for Run II

    CERN Document Server

    Klein, Jochen

    2016-01-01

    The ALICE Transition Radiation Detector contributes to the tracking, particle identification, and triggering capabilities of the experiment. It is composed of six layers of multi-wire proportional chambers, each of which is preceded by a radiator and a Xe/CO$_2$-filled drift volume. The signal is sampled in timebins of 100~ns over the drift length which allows for the reconstruction of chamber-wise track segments, both online and offline. The particle identification is based on the specific energy loss of charged particles and additional transition radiation photons, the latter being a signature for electrons. The detector is segmented into 18 sectors, of which 13 were installed in Run I. The TRD was included in data taking since the LHC start-up and was successfully used for electron identification and triggering. During the Long Shutdown 1, the detector was completed and now covers the full azimuthal acceptance. Furthermore, the readout and trigger components were upgraded. When data taking was started for ...

  12. The time-walk of analog constant fraction discriminators using very fast scintillator detectors with linear and non-linear energy response

    Energy Technology Data Exchange (ETDEWEB)

    Regis, J.-M., E-mail: regis@ikp.uni-koeln.de [Institut fuer Kernphysik der Universitaet zu Koeln, Zuelpicher Str. 77, 50937 Koeln (Germany); Rudigier, M.; Jolie, J.; Blazhev, A.; Fransen, C.; Pascovici, G.; Warr, N. [Institut fuer Kernphysik der Universitaet zu Koeln, Zuelpicher Str. 77, 50937 Koeln (Germany)

    2012-08-21

    The electronic {gamma}-{gamma} fast timing technique allows for direct nuclear lifetime determination down to the few picoseconds region by measuring the time difference between two coincident {gamma}-ray transitions. Using high resolution ultra-fast LaBr{sub 3}(Ce) scintillator detectors in combination with the recently developed mirror symmetric centroid difference method, nuclear lifetimes are measured with a time resolving power of around 5 ps. The essence of the method is to calibrate the energy dependent position (centroid) of the prompt response function of the setup which is obtained for simultaneously occurring events. This time-walk of the prompt response function induced by the analog constant fraction discriminator has been determined by systematic measurements using different photomultiplier tubes and timing adjustments of the constant fraction discriminator. We propose a universal calibration function which describes the time-walk or the combined {gamma}-{gamma} time-walk characteristics, respectively, for either a linear or a non-linear amplitude versus energy dependency of the scintillator detector output pulses.

  13. A fast and precise chemiluminescence ozone detector for eddy flux and airborne application

    Directory of Open Access Journals (Sweden)

    A. Zahn

    2012-02-01

    Full Text Available A commercially available dry chemiluminescence (CI instrument for fast and precise measurement of ozone (O3 is specified. The sensitivity is ~9000 counts s−1 per ppbv of ozone. Its precision is entirely determined by the number of photons reaching the detector (being a photomultiplier, i.e. is quantum-noise limited. The relative precision (ΔO3/O3 in % thus follows Poisson statistics and scales with the square root of the measurement frequency f and with the inverse O3 mixing ratio: ΔO3/O3f0.5 · O3−0.5. At typical O3 mixing ratios between 10 and 100 ppbv (and 1 bar, the precision is 0.3–1.0% at f = 10 Hz. The maximum measurement frequency is 50 Hz. The mechanical and electronic set-up as well as the instrument performance is described. Recommendations on the adequate inlet tube configuration (inlet tube length, sampling flow and on the way of calibration at stationary ground-based platforms and onboard aircraft are given.

  14. Advancements in the development of a directional-position sensing fast neutron detector using acoustically tensioned metastable fluids

    Energy Technology Data Exchange (ETDEWEB)

    Archambault, Brian C. [Sagamore Adams Laboratories, Lafayette, IN (United States); Webster, Jeffrey A.; Grimes, Thomas F.; Fischer, Kevin F.; Hagen, Alex R. [School of Nuclear Engineering, Purdue University, 400 Central Avenue, West Lafayette, IN 47907 (United States); Taleyakhan, Rusi P., E-mail: rusi@purdue.edu [Sagamore Adams Laboratories, Lafayette, IN (United States); School of Nuclear Engineering, Purdue University, 400 Central Avenue, West Lafayette, IN 47907 (United States)

    2015-06-01

    Advancements in the development of a direction and position sensing fast neutron detector which utilizes the directional acoustic tensioned metastable fluid detector (D-ATMFD) are described. The resulting D-ATMFD sensor is capable of determining the direction of neutron radiation with a single compact detector versus use of arrays of detectors in conventional directional systems. Directional neutron detection and source positioning offer enhanced detection speeds in comparison to traditional proximity searching; including enabling determination of the neutron source shape, size, and strength in near real time. This paper discusses advancements that provide the accuracy and precision of ascertaining directionality and source localization information utilizing enhanced signal processing-cum-signal analysis, refined computational algorithms, and on-demand enlargement capability of the detector sensitive volume. These advancements were accomplished utilizing experimentation and theoretical modeling. Benchmarking and qualifications studies were successfully conducted with random and fission based special nuclear material (SNM) neutron sources ({sup 239}Pu–Be and {sup 252}Cf). These results of assessments have indicated that the D-ATMFD compares well in technical performance with banks of competing directional fast neutron detector technologies under development worldwide, but it does so with a single detector unit, an unlimited field of view, and at a significant reduction in both cost and size while remaining completely blind to common background (e.g., beta-gamma) radiation. Rapid and direct SNM neutron source imaging with two D-ATMFD sensors was experimentally demonstrated, and furthermore, validated via multidimensional nuclear particle transport simulations utilizing MCNP-PoliMi. Characterization of a scaled D-ATMFD based radiation portal monitor (RPM) as a cost-effective and efficient {sup 3}He sensor replacement was performed utilizing MCNP-PoliMi simulations

  15. A calorimetric particle detector using an iridium superconducting phase transition thermometer

    International Nuclear Information System (INIS)

    Frank, M.; Dummer, D.; Cooper, S.; Igalson, J.; Proebst, F.; Seidel, W.

    1994-01-01

    We report on a calorimetric particles detector consisting of an 18.3 g silicon crystal and an iridium superconducting phase transition thermometer. The cryogenic calorimeter and the associated apparatus are described in detail. The pulses from irradiation with an α-particle source have a large unexpected overshoot in addition to the component expected from a naive thermal model. The pulse height spectrum displays an energy resolution of 1 percent FWHM at 6 MeV and good linearity. The noise, electrothermal feedback, and position dependence are discussed. (orig.)

  16. Energy loss and online directional track visualization of fast electrons with the pixel detector Timepix

    Czech Academy of Sciences Publication Activity Database

    Granja, C.; Krist, Pavel; Chvátil, David; Šolc, J.; Pospíšil, S.; Jakubek, J.; Opalka, L.

    2013-01-01

    Roč. 59, DEC (2013), s. 245-261 ISSN 1350-4487 Institutional support: RVO:61389005 Keywords : interaction of radiation with matter * dE/dx detectors * particle tracking detectors * hybrid pixel detectors * active nuclear emulsion * energy loss Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 1.140, year: 2013

  17. Note: Measurements of fast electrons in the TORE-SUPRA tokamak by means of modified Cherenkov-type diamond detector

    Energy Technology Data Exchange (ETDEWEB)

    Jakubowski, L.; Sadowski, M. J.; Zebrowski, J.; Rabinski, M.; Jakubowski, M. J.; Malinowski, K.; Mirowski, R. [National Centre for Nuclear Research (NCBJ), 7 Andrzeja Soltana Str., 05-400 Otwock (Poland); Lotte, Ph.; Goniche, M.; Gunn, J.; Colledani, G.; Pascal, J.-Y.; Basiuk, V. [CEA, IRFM, F-13108 Saint Paul-lez-Durance (France)

    2013-01-15

    The Note reports on experimental studies of ripple born fast electrons within the TORE-SUPRA facility, which were performed by means of a modified measuring head equipped with diamond detectors designed especially for recording the electron-induced Cherenkov radiation. There are presented signals produced by fast electrons in the TORE-SUPRA machine, which were recorded during two experimental campaigns performed in 2010. Shapes of these electron-induced signals are considerably different from those observed during the first measurements carried out by the prototype Cherenkov probe in 2008. An explanation of the observed differences is given.

  18. Note: Measurements of fast electrons in the TORE-SUPRA tokamak by means of modified Cherenkov-type diamond detector

    International Nuclear Information System (INIS)

    Jakubowski, L.; Sadowski, M. J.; Zebrowski, J.; Rabinski, M.; Jakubowski, M. J.; Malinowski, K.; Mirowski, R.; Lotte, Ph.; Goniche, M.; Gunn, J.; Colledani, G.; Pascal, J.-Y.; Basiuk, V.

    2013-01-01

    The Note reports on experimental studies of ripple born fast electrons within the TORE-SUPRA facility, which were performed by means of a modified measuring head equipped with diamond detectors designed especially for recording the electron-induced Cherenkov radiation. There are presented signals produced by fast electrons in the TORE-SUPRA machine, which were recorded during two experimental campaigns performed in 2010. Shapes of these electron-induced signals are considerably different from those observed during the first measurements carried out by the prototype Cherenkov probe in 2008. An explanation of the observed differences is given.

  19. Strategic and policy issues raised by the transition from thermal to fast nuclear systems

    International Nuclear Information System (INIS)

    2009-01-01

    The renewed interest in nuclear energy triggered by concerns about global climate change and security of supply, which could lead to substantial growth in nuclear electricity generation, enhances the attractiveness of fast neutron reactors with closed fuel cycles. Moving from the current fleet of thermal neutron reactors to fast neutron systems will require many decades and extensive RD-D efforts. This book identifies and analyses key strategic and policy issues raised by such a transition, aiming at providing guidance to decision makers on the best approaches for implementing transition scenarios. The topics covered in this book will be of interest to government and nuclear industry policy makers as well as to specialists working on nuclear energy system analyses and advanced fuel cycle issues. (author)

  20. Modular pixelated detector system with the spectroscopic capability and fast parallel read-out

    Czech Academy of Sciences Publication Activity Database

    Vavřík, Daniel; Holík, M.; Jakůbek, J.; Jakůbek, M.; Kraus, V.; Krejčí, F.; Soukup, P.; Tureček, D.; Vacík, Jiří; Žemlička, J.

    2014-01-01

    Roč. 9, June (2014), C06006 ISSN 1748-0221. [International workshop on radiation imaging detectors /15./. Paris, 23.06.2013-27.06.2013] R&D Projects: GA MŠk(CZ) LO1219; GA TA ČR(CZ) TA01010237 Institutional support: RVO:68378297 ; RVO:61389005 Keywords : particle tracking detectors * X-ray detectors * modular electronics * neutron detectors * solid-state detectors Subject RIV: JN - Civil Engineering; BM - Solid Matter Physics ; Magnetism (UJF-V) Impact factor: 1.399, year: 2014 http://iopscience.iop.org/1748-0221/9/06/C06006

  1. Development of a new fast shower maximum detector based on microchannel plates photomultipliers (MCP-PMT) as an active element

    Energy Technology Data Exchange (ETDEWEB)

    Ronzhin, A., E-mail: ronzhin@fnal.gov [Fermilab, Batavia, IL 60510 (United States); Los, S.; Ramberg, E. [Fermilab, Batavia, IL 60510 (United States); Spiropulu, M.; Apresyan, A.; Xie, S. [California Institute of Technology, Pasadena, CA (United States); Kim, H. [University of Chicago, Chicago, IL 60637 (United States); Zatserklyaniy, A. [University of California, Santa Cruz, CA (United States)

    2014-09-21

    One possibility to make a fast and radiation resistant shower maximum (SM) detector is to use a secondary emitter as an active element. We present below test beam results, obtained with different types of photodetectors based on microchannel plates (MCPs) as the secondary emitter. We performed the measurements at the Fermilab Test Beam Facility with 120 GeV proton beam and 12 GeV and 32 GeV secondary beams. The goal of the measurement with 120 GeV protons was to determine time resolution for minimum ionizing particles (MIPs). The SM time resolution we obtained for this new type of detector is at the level of 20–30 ps. We estimate that a significant contribution to the detector response originates from secondary emission of the MCP. This work can be considered as the first step in building a new type of calorimeter based on this principle.

  2. Simulating a topological transition in a superconducting phase qubit by fast adiabatic trajectories

    Science.gov (United States)

    Wang, Tenghui; Zhang, Zhenxing; Xiang, Liang; Gong, Zhihao; Wu, Jianlan; Yin, Yi

    2018-04-01

    The significance of topological phases has been widely recognized in the community of condensed matter physics. The well controllable quantum systems provide an artificial platform to probe and engineer various topological phases. The adiabatic trajectory of a quantum state describes the change of the bulk Bloch eigenstates with the momentum, and this adiabatic simulation method is however practically limited due to quantum dissipation. Here we apply the "shortcut to adiabaticity" (STA) protocol to realize fast adiabatic evolutions in the system of a superconducting phase qubit. The resulting fast adiabatic trajectories illustrate the change of the bulk Bloch eigenstates in the Su-Schrieffer-Heeger (SSH) model. A sharp transition is experimentally determined for the topological invariant of a winding number. Our experiment helps identify the topological Chern number of a two-dimensional toy model, suggesting the applicability of the fast adiabatic simulation method for topological systems.

  3. Fast track-finding trigger processor for the SLAC/LBL Mark II Detector

    International Nuclear Information System (INIS)

    Brafman, H.; Breidenbach, M.; Hettel, R.; Himel, T.; Horelick, D.

    1977-10-01

    The SLAC/LBL Mark II Magnetic Detector consists of various particle detectors arranged in cylindrical symmetry located in and around an axial magnetic field. A versatile, programmable secondary trigger processor was designed and built to find curved tracks in the detector. The system operates at a 10 MHz clock rate with a total processing time of 34 μsec and is used to ''trigger'' the data processing computer, thereby rejecting background and greatly improving the data acquisition aspects of the detector-computer combination

  4. 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.

  5. 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

  6. Faster recovery of gastrointestinal transit after laparoscopy and fast-track care in patients undergoing colonic surgery

    NARCIS (Netherlands)

    van Bree, Sjoerd; Vlug, Malaika; Bemelman, Willem; Hollmann, Markus; Ubbink, Dirk; Zwinderman, Koos; de Jonge, Wouter; Snoek, Susanne; Bolhuis, Karen; van der Zanden, Esmerij; The, Frans; Bennink, Roel; Boeckxstaens, Guy

    2011-01-01

    Postoperative ileus is characterized by delayed gastrointestinal (GI) transit and is a major determinant of recovery after colorectal surgery. Both laparoscopic surgery and fast-track multimodal perioperative care have been reported to improve clinical recovery. However, objective measures

  7. Fast tracking detector with fiber scintillators and a position sensitive photomultiplier

    International Nuclear Information System (INIS)

    Salomon, M.; Li, V.; Smith, G.; Wu, Y.S.

    1988-11-01

    We have studied the properties of a tracking detector composed of 32 fiber scintillators coupled to a multianode photomultiplier placed in a pion beam at TRIUMF. We measured the efficiency of the detector, as well as its tracking capabilities and double hit resolution

  8. The mirror symmetric centroid difference method for picosecond lifetime measurements via {gamma}-{gamma} coincidences using very fast LaBr{sub 3}(Ce) scintillator detectors

    Energy Technology Data Exchange (ETDEWEB)

    Regis, J.-M., E-mail: regis@ikp.uni-koeln.d [Institut fuer Kernphysik, Universitaet zu Koeln, Zuelpicher Str. 77, 50937 Koeln (Germany); Pascovici, G.; Jolie, J.; Rudigier, M. [Institut fuer Kernphysik, Universitaet zu Koeln, Zuelpicher Str. 77, 50937 Koeln (Germany)

    2010-10-01

    The ultra-fast timing technique was introduced in the 1980s and is capable of measuring picosecond lifetimes of nuclear excited states with about 3 ps accuracy. Very fast scintillator detectors are connected to an electronic timing circuit and detector vs. detector time spectra are analyzed by means of the centroid shift method. The very good 3% energy resolution of the nowadays available LaBr{sub 3}(Ce) scintillator detectors for {gamma}-rays has made possible an extension of the well-established fast timing technique. The energy dependent fast timing characteristics or the prompt curve, respectively, of the LaBr{sub 3}(Ce) scintillator detector has been measured using a standard {sup 152}Eu {gamma}-ray source. For any energy combination in the range of 200keVfast timing characteristics is calibrated as a function of energy with an accuracy of 2-4 ps. An extension of the centroid shift method providing very attractive features for picosecond lifetime measurements is presented. The mirror symmetric centroid difference method takes advantage of the symmetry obtained when performing {gamma}-{gamma} lifetime measurements using a pair of almost identical very fast scintillator detectors. In particular cases, the use of the mirror symmetric centroid difference method also allows the direct determination of picosecond lifetimes, hence without the need of calibrating the prompt curve.

  9. Fast neutron detection with germanium detectors: computation of response functions for the 692 keV inelastic scattering peak

    International Nuclear Information System (INIS)

    Fehrenbacher, G.; Meckbach, R.; Paretzke, H.G.

    1996-01-01

    The dependence of the shape of the right-sided broadening of the inelastic scattering peak at 692 keV in the pulse-height distribution measured with a Ge detector in fast neutron fields on the energy of the incident neutrons has been analyzed. A model incorporating the process contributing to the energy deposition that engender the peak, including the partitioning of the energy deposition by the Ge recoils, was developed. With a Monte Carlo code based on this model, the detector response associated with this peak was computed and compared with results of measurements with quasi-monoenergetic neutrons for energies between 0.88 and 2.1 MeV. A set of 80 response functions for neutron energies in the range from the reaction threshold at 0.7 to 6 MeV was computed, which will serve as a starting point for methods, which aim at obtaining information on the spectral distribution of fast neutron fields for this energy range from measurements with a Ge detector. (orig.)

  10. Development of a transition radiation detector and reconstruction of photon conversions in the CBM experiment

    International Nuclear Information System (INIS)

    Klein-Boesing, Melanie

    2009-01-01

    The focus of this thesis is the development of a Transition Radiation Detector (TRD) for the Compressed Baryonic Matter (CBM) experiment at the future Facility for Antiproton and Ion Research (FAIR) in Darmstadt. In addition, the usage of the TRD in the measurement of direct photons is investigated. CBM will be a fixed-target heavy-ion experiment, which investigates collisions in the beam energy range of 5-35 AGeV and aims to investigate the regime of high baryon densities where the phase transition is expected to be of first order. It will be a multipurpose experiment with the ability to measure leptons, hadrons, and photons. Therein, a TRD will provide the electron identification and - together with a Silicon Tracking System (STS) - the tracking of charged particles. In conjunction with a ring imaging Cherenkov (RICH) detector and a time-of-flight (TOF) measurement, the TRD is to provide a sufficient electron identification for the measurements of charmonium and low-mass vector mesons. For the TRD, the required pion suppression is a factor of about 100 at 90% electron efficiency, and the position resolution has to be of the order of 300 to 500 um. Moreover, the material budget in terms of radiation length has to be kept at a minimum in order to minimize multiple scattering and conversions which would limit the precise measurement in following TRD stations and other detectors. The largest and up to now unrivaled challenge for the TRD design is that both (PID and tracking) have to be fulfilled in the context of very high particle rates (event rates of up to 10MHz are envisaged) and at the same time large charged-particle multiplicities of up to 600 per event in the CBM detector acceptance. Small prototypes of the TRD based on multiwire proportional chambers (MWPC) with pad readout were developed and tested. The tracking performance and the electron-pion separation were determined for particle rates of up to 200 kHz/cm 2 . The TRD layout and the detector responses

  11. Development of a transition radiation detector and reconstruction of photon conversions in the CBM experiment

    Energy Technology Data Exchange (ETDEWEB)

    Klein-Boesing, Melanie

    2009-07-01

    The focus of this thesis is the development of a Transition Radiation Detector (TRD) for the Compressed Baryonic Matter (CBM) experiment at the future Facility for Antiproton and Ion Research (FAIR) in Darmstadt. In addition, the usage of the TRD in the measurement of direct photons is investigated. CBM will be a fixed-target heavy-ion experiment, which investigates collisions in the beam energy range of 5-35 AGeV and aims to investigate the regime of high baryon densities where the phase transition is expected to be of first order. It will be a multipurpose experiment with the ability to measure leptons, hadrons, and photons. Therein, a TRD will provide the electron identification and - together with a Silicon Tracking System (STS) - the tracking of charged particles. In conjunction with a ring imaging Cherenkov (RICH) detector and a time-of-flight (TOF) measurement, the TRD is to provide a sufficient electron identification for the measurements of charmonium and low-mass vector mesons. For the TRD, the required pion suppression is a factor of about 100 at 90% electron efficiency, and the position resolution has to be of the order of 300 to 500 um. Moreover, the material budget in terms of radiation length has to be kept at a minimum in order to minimize multiple scattering and conversions which would limit the precise measurement in following TRD stations and other detectors. The largest and up to now unrivaled challenge for the TRD design is that both (PID and tracking) have to be fulfilled in the context of very high particle rates (event rates of up to 10MHz are envisaged) and at the same time large charged-particle multiplicities of up to 600 per event in the CBM detector acceptance. Small prototypes of the TRD based on multiwire proportional chambers (MWPC) with pad readout were developed and tested. The tracking performance and the electron-pion separation were determined for particle rates of up to 200 kHz/cm{sup 2}. The TRD layout and the detector

  12. Detecting an infrared photon within an hour. Transition-edge detector at ALPS-II

    Energy Technology Data Exchange (ETDEWEB)

    Dreyling-Eschweiler, Jan [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Hamburg Univ. (Germany). Inst. fuer Experimentalphysik; Horns, Dieter [Hamburg Univ. (Germany). Inst. fuer Experimentalphysik; Collaboration: ALPS-II collaboration

    2013-09-15

    An essential design requirement of the ALPS-II experiment is the efficient detection of single photons with a very low instrumental background of 10 {mu}Hz. In 2011 the ALPS collaboration started to set up a TES detector (Transition-Edge Sensor) for ALPS-II, the second phase of the experiment. Since mid of 2013 the setup is ready for characterization in the ALPS laboratory: an ADR cryostat (Adiabatic Demagnetization Refrigerator) as millikelvin environment, a low noise SQUID (Superconducting Quantum Interference Device) with electronics for read-out and a fiber-coupled high-efficient TES for near-infrared photons as sensor. First measurements have shown a good discrimination between noise and 1064 nm signals.

  13. Detecting an infrared photon within an hour. Transition-edge detector at ALPS-II

    International Nuclear Information System (INIS)

    Dreyling-Eschweiler, Jan; Hamburg Univ.; Horns, Dieter

    2013-09-01

    An essential design requirement of the ALPS-II experiment is the efficient detection of single photons with a very low instrumental background of 10 μHz. In 2011 the ALPS collaboration started to set up a TES detector (Transition-Edge Sensor) for ALPS-II, the second phase of the experiment. Since mid of 2013 the setup is ready for characterization in the ALPS laboratory: an ADR cryostat (Adiabatic Demagnetization Refrigerator) as millikelvin environment, a low noise SQUID (Superconducting Quantum Interference Device) with electronics for read-out and a fiber-coupled high-efficient TES for near-infrared photons as sensor. First measurements have shown a good discrimination between noise and 1064 nm signals.

  14. Development of SiPM-based scintillator tile detectors for a multi-layer fast neutron tracker

    Directory of Open Access Journals (Sweden)

    Jakubek J.

    2012-10-01

    Full Text Available We are developing thin tile scintillator detectors with silicon photomultiplier (SiPM readout for use in a multi-layer fast-neutron tracker. The tracker is based on interleaved Timepix and plastic scintillator layers. The thin 15 × 15 × 2 mm plastic scintillators require suitable optical readout in order to detect and measure the energy lost by energetic protons that have been recoiled by fast neutrons. Our first prototype used dual SiPMs, coupled to opposite edges of the scintillator tile using light-guides. An alternative readout geometry was designed in an effort to increase the fraction of scintillation light detected by the SiPMs. The new prototype uses a larger SiPM array to cover the entire top face of the tile. This paper details the comparative performance of the two prototype designs. A deuterium-tritium (DT fast-neutron source was used to compare the relative light collection efficiency of the two designs. A collimated UV light source was scanned across the detector face to map the uniformity. The new prototype was found to have 9.5 times better light collection efficiency over the original design. Both prototypes exhibit spatial non-uniformity in their response. Methods of correcting this non-uniformity are discussed.

  15. The development of two ASIC's for a fast silicon strip detector readout system

    International Nuclear Information System (INIS)

    Christain, D.; Haldeman, M.; Yarema, R.; Zimmerman, T.; Newcomer, F.M.; VanBerg, R.

    1989-01-01

    A high speed, low noise readout system for silicon strip detectors is being developed for Fermilab E771, which will begin taking data in 1989. E771 is a fixed target experiment designed to study the production of B hadrons by an 800 GeV/c proton beam. The experimental apparatus consists of an open geometry magnetic spectrometer featuring good muon and electron identification and a 16000 channel silicon microstrip vertex detector. This paper reviews the design and prototyping of two application specific integrated circuits (ASIC's) an amplifier and a discriminator, which are being produced for the silicon strip detector readout system

  16. RNA sequencing reveals a slow to fast muscle fiber type transition after olanzapine infusion in rats.

    Directory of Open Access Journals (Sweden)

    Christopher J Lynch

    Full Text Available Second generation antipsychotics (SGAs, like olanzapine, exhibit acute metabolic side effects leading to metabolic inflexibility, hyperglycemia, adiposity and diabetes. Understanding how SGAs affect the skeletal muscle transcriptome could elucidate approaches for mitigating these side effects. Male Sprague-Dawley rats were infused intravenously with vehicle or olanzapine for 24h using a dose leading to a mild hyperglycemia. RNA-Seq was performed on gastrocnemius muscle, followed by alignment of the data with the Rat Genome Assembly 5.0. Olanzapine altered expression of 1347 out of 26407 genes. Genes encoding skeletal muscle fiber-type specific sarcomeric, ion channel, glycolytic, O2- and Ca2+-handling, TCA cycle, vascularization and lipid oxidation proteins and pathways, along with NADH shuttles and LDH isoforms were affected. Bioinformatics analyses indicate that olanzapine decreased the expression of slower and more oxidative fiber type genes (e.g., type 1, while up regulating those for the most glycolytic and least metabolically flexible, fast twitch fiber type, IIb. Protein turnover genes, necessary to bring about transition, were also up regulated. Potential upstream regulators were also identified. Olanzapine appears to be rapidly affecting the muscle transcriptome to bring about a change to a fast-glycolytic fiber type. Such fiber types are more susceptible than slow muscle to atrophy, and such transitions are observed in chronic metabolic diseases. Thus these effects could contribute to the altered body composition and metabolic disease olanzapine causes. A potential interventional strategy is implicated because aerobic exercise, in contrast to resistance exercise, can oppose such slow to fast fiber transitions.

  17. Faraday-cup-type lost fast ion detector on Heliotron J

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, S., E-mail: yamamoto.satoshi.6n@kyoto-u.ac.jp; Kobayashi, S.; Nagasaki, K.; Okada, H.; Minami, T.; Kado, S.; Ohshima, S.; Weir, G. M.; Konoshima, S.; Mizuuchi, T. [Institute of Advanced Energy, Kyoto University, Gokasho, Uji, Kyoto 611-0011 (Japan); Ogawa, K.; Isobe, M. [National Institute for Fusion Science, National Institutes of Natural Sciences, 322-6 Oroshi, Toki, Gifu 509-5292 (Japan); SOKENDAI (The Graduate University for Advanced Studies), 322-6 Oroshi, Toki, Gifu 509-5292 (Japan); Darrow, D. S. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States); Nakamura, Y.; Ohtani, Y. [Graduate School of Energy Science, Kyoto University, Gokasho, Uji, Kyoto 611-0011 (Japan); Kemmochi, N. [National Institute for Fusion Science, National Institutes of Natural Sciences, 322-6 Oroshi, Toki, Gifu 509-5292 (Japan)

    2016-11-15

    A Faraday-cup type lost-fast ion probe (FLIP) has been designed and installed in Heliotron J for the purpose of the studies of interaction between fast ions and MHD instabilities. The FLIP can measure the co-going fast ions whose energy is in the range of 1.7–42.5 keV (proton) and pitch angle of 90{sup ∘}–140{sup ∘}, especially for fast ions having the injection energy of neutral beam injection (NBI). The FLIP successfully measured the re-entering passing ions and trapped lost-fast ions caused by fast-ion-driven energetic particle modes in NBI heated plasmas.

  18. Assessment of fast and thermal neutron ambient dose equivalents around the KFUPM neutron source storage area using nuclear track detectors

    Energy Technology Data Exchange (ETDEWEB)

    Fazal-ur-Rehman [Physics Department, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia)]. E-mail: fazalr@kfupm.edu.sa; Al-Jarallah, M.I. [Physics Department, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Abu-Jarad, F. [Radiation Protection Unit, Environmental Protection Department, Saudi Aramco, P. O. Box 13027, Dhahran 31311 (Saudi Arabia); Qureshi, M.A. [Center for Applied Physical Sciences, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia)

    2005-11-15

    A set of five {sup 241}Am-Be neutron sources are utilized in research and teaching at King Fahd University of Petroleum and Minerals (KFUPM). Three of these sources have an activity of 16Ci each and the other two are of 5Ci each. A well-shielded storage area was designed for these sources. The aim of the study is to check the effectiveness of shielding of the KFUPM neutron source storage area. Poly allyl diglycol carbonate (PADC) Nuclear track detectors (NTDs) based fast and thermal neutron area passive dosimeters have been utilized side by side for 33 days to assess accumulated low ambient dose equivalents of fast and thermal neutrons at 30 different locations around the source storage area and adjacent rooms. Fast neutron measurements have been carried out using bare NTDs, which register fast neutrons through recoils of protons, in the detector material. NTDs were mounted with lithium tetra borate (Li{sub 2}B{sub 4}O{sub 7}) converters on their surfaces for thermal neutron detection via B10(n,{alpha})Li6 and Li6(n,{alpha})H3 nuclear reactions. The calibration factors of NTD both for fast and thermal neutron area passive dosimeters were determined using thermoluminescent dosimeters (TLD) with and without a polyethylene moderator. The calibration factors for fast and thermal neutron area passive dosimeters were found to be 1.33 proton tracks cm{sup -2}{mu}Sv{sup -1} and 31.5 alpha tracks cm{sup -2}{mu}Sv{sup -1}, respectively. The results show variations of accumulated dose with the locations around the storage area. The fast neutron dose equivalents rates varied from as low as 182nSvh{sup -1} up to 10.4{mu}Svh{sup -1} whereas those for thermal neutron ranged from as low as 7nSvh{sup -1} up to 9.3{mu}Svh{sup -1}. The study indicates that the area passive neutron dosimeter was able to detect dose rates as low as 7 and 182nSvh{sup -1} from accumulated dose for thermal and fast neutrons, respectively, which were not possible to detect with the available active neutron

  19. Measuring fast neutrons with large liquid scintillation detector for ultra-low background experiments

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, C. [Department of Physics, The University of South Dakota, Vermillion, SD 57069 (United States); College of Sciences, China Three Gorges University, Yichang 443002 (China); Mei, D.-M., E-mail: dongming.mei@usd.edu [Department of Physics, The University of South Dakota, Vermillion, SD 57069 (United States); Davis, P.; Woltman, B. [Department of Physics, The University of South Dakota, Vermillion, SD 57069 (United States); Gray, F. [Department of Physics and Computational Science, Regis University, Denver, CO 80221 (United States)

    2013-11-21

    We developed a 12-liter volume neutron detector filled with the liquid scintillator EJ301 that measures neutrons in an underground laboratory where dark matter and neutrino experiments are located. The detector target is a cylindrical volume coated on the inside with reflective paint (95% reflectivity) that significantly increases the detector's light collection. We demonstrate several calibration techniques using point sources and cosmic-ray muons for energies up to 20 MeV for this large liquid scintillation detector. Neutron–gamma separation using pulse shape discrimination with a few MeV neutrons to hundreds of MeV neutrons is shown for the first time using a large liquid scintillator.

  20. A fast and compact electromagnetic calorimeter for the PANDA detector at FAIR

    International Nuclear Information System (INIS)

    Wilms, Andrea

    2005-01-01

    In this presentation we report on the electromagnetic calorimeter of the 4π detector PANDA to be installed at the antiproton storage ring of the proposed Facility for Antiproton and Ion Research (FAIR). We present details of the R and D work with two scintillator materials, PbWO4 (PWO) and BGO, and the new developed large area avalanche photodiodes (LAAPDs) as detector readout

  1. Optimisation of a collimator array for a multi-detector time-of-flight spectrometer for fast neutrons

    International Nuclear Information System (INIS)

    Schlegel-Bickmann, D.

    1979-01-01

    A Monte Carlo program has been developed which calculates the neutron background due to the interaction between incident neutrons and the collimator fan near the detector in dependence of geometry and material parameters. The position of the neutron source with regard to the collimators may be chosen at random. The program is also suitable for other three-dimensional transport problems of fast neutrons in the energy range between 0.5 and 20 MeV. The modular structure makes it easy to adapt it to highly specific problems. (orig.) 891 HP 892 MB [de

  2. Fast Watermarking of MPEG-1/2 Streams Using Compressed-Domain Perceptual Embedding and a Generalized Correlator Detector

    Directory of Open Access Journals (Sweden)

    Briassouli Alexia

    2004-01-01

    Full Text Available A novel technique is proposed for watermarking of MPEG-1 and MPEG-2 compressed video streams. The proposed scheme is applied directly in the domain of MPEG-1 system streams and MPEG-2 program streams (multiplexed streams. Perceptual models are used during the embedding process in order to avoid degradation of the video quality. The watermark is detected without the use of the original video sequence. A modified correlation-based detector is introduced that applies nonlinear preprocessing before correlation. Experimental evaluation demonstrates that the proposed scheme is able to withstand several common attacks. The resulting watermarking system is very fast and therefore suitable for copyright protection of compressed video.

  3. A fast preamplifier concept for SiPM-based time-of-flight PET detectors

    NARCIS (Netherlands)

    Huizenga, J.; Seifert, S.; Schreuder, F.; Dendooven, P.; Löhner, H.; Vinke, R.; Schaart, D. R.; van Dam, H.T.

    2012-01-01

    Silicon photomultipliers (SiPMs) offer high gain and fast response to light, making them interesting for fast timing applications such as time-of-flight (TOF) PET. To fully exploit the potential of these photosensors, dedicated preamplifiers that do not deteriorate the rise time and signal-to-noise

  4. Transition radiation detectors for electron identification beyond 1 GeV/c

    International Nuclear Information System (INIS)

    Appuhn, R.D.; Heinloth, K.; Lange, E.; Oedingen, R.; Schloesser, A.

    1987-07-01

    Transition radiation detectors (TRDs) have been tested for the separation of electrons from pions in the momentum range between 1 GeV/c and 6 GeV/c. Foams as well as fibres and foils served as radiator materials while two types of chambers, a longitudinal drift chamber (DC) and a multiwire proportional chamber (MWPC), both of 16 mm depth and dominantly filled with xenon, were used for detecting the transition radiation photons with a setup of four chambers. Analyzing the data we compared the methods of mean, truncated mean and of maximum likelihood of the total charge measurements and several methods of cluster analysis. As a result of the total charge measurements performed at test beams at CERN and DESY we obtained about 1% pion contamination at 90% electron efficiency for the polypropylene materials in the configuration of four modules with a total length of 40 cm. An improvement by a factor of about two for the electron/pion discrimination can be obtained in case of a detailed analysis of the clusters. (orig.)

  5. Timing and position response of a block detector for fast neutron time-of-flight imaging

    Energy Technology Data Exchange (ETDEWEB)

    Laubach, M.A., E-mail: mlaubach@utk.edu [Department of Nuclear Engineering, University of Tennessee, Knoxville, TN 37996 (United States); Hayward, J.P., E-mail: jhayward@utk.edu [Department of Nuclear Engineering, University of Tennessee, Knoxville, TN 37996 (United States); Oak Ridge National Laboratory, 1 Bethel Valley Rd., Oak Ridge, TN 37831 (United States); Zhang, X., E-mail: xzhang39@utk.edu [Department of Nuclear Engineering, University of Tennessee, Knoxville, TN 37996 (United States); Cates, J.W., E-mail: jcates7@vols.utk.edu [Department of Nuclear Engineering, University of Tennessee, Knoxville, TN 37996 (United States)

    2014-11-01

    Our research effort seeks to improve the spatial and timing performance of a block detector made of a pixilated plastic scintillator (EJ-200), first demonstrated as part of Oak Ridge National Laboratory's Advanced Portable Neutron Imaging System. Improvement of the position and time response is necessary to achieve better resolution and contrast in the images of shielded special nuclear material. Time-of-flight is used to differentiate between gamma and different sources of neutrons (e.g., transmission and fission neutrons). Factors limiting the timing and position performance of the neutron detector have been revealed through simulations and measurements. Simulations have suggested that the degradation in the ability to resolve pixels in the neutron detector is due to those interactions occurring near the light guide. The energy deposition within the neutron detector is shown to affect position performance and imaging efficiency. This examination details how energy cuts improve the position performance and degrade the imaging efficiency. Measurements have shown the neutron detector to have a timing resolution of σ=238 ps. The majority of this timing uncertainty is from the depth-of-interaction (DOI) of the neutron which is confirmed by simulations and analytical calculations.

  6. Studies on a pulse shaping system for fast coincidence with very large volume HPGe detectors

    International Nuclear Information System (INIS)

    Bose, S.; Chatterjee, M.B.; Sinha, B.K.; Bhattacharya, R.

    1987-01-01

    A variant of the leading edge timing (LET) has been proposed which compensates the ''walk'' due to risetime spread in very large volume (∝100 cm 3 ) HPGe detectors. The method - shape compensated leading edge timing (SCLET) - can be used over a wide dynamic range of energies with 100% efficiency and has been compared with the LET and ARC methods. A time resolution of 10 ns fwhm and 21 ns fwtm has been obtained with 22 Na gamma rays and two HPGe detectors of 96 and 114 cm 3 volume. This circuit is easy to duplicate and use can be a low cost alternative to commercial circuits in experiments requiring a large number of detectors. (orig.)

  7. Development of the microstrip silicon detector for imaging of fast processes at a synchrotron radiation beam

    Energy Technology Data Exchange (ETDEWEB)

    Aulchenko, V. [Budker Institute of Nuclear Physics, 630090 Novosibirsk (Russian Federation); Novosibirsk State University, 630090 Novosibirsk, Russian Federtion (Russian Federation); Pruuel, E. [Lavrentiev Institute of Hydrodynamics, 630090 Novosibirsk, Russian Federtion (Russian Federation); Novosibirsk State University, 630090 Novosibirsk, Russian Federtion (Russian Federation); Shekhtman, L. [Budker Institute of Nuclear Physics, 630090 Novosibirsk (Russian Federation); Novosibirsk State University, 630090 Novosibirsk, Russian Federtion (Russian Federation); Ten, K. [Lavrentiev Institute of Hydrodynamics, 630090 Novosibirsk, Russian Federtion (Russian Federation); Tolochko, B. [Institute of Solid State chemistry and Mechanochemistry, 630090 Novosibirsk, Russian Federtion (Russian Federation); Novosibirsk State University, 630090 Novosibirsk, Russian Federtion (Russian Federation); Zhulanov, V. [Budker Institute of Nuclear Physics, 630090 Novosibirsk (Russian Federation); Novosibirsk State University, 630090 Novosibirsk, Russian Federtion (Russian Federation)

    2017-02-11

    In situ imaging of explosions allows to study material properties under very high pressures and temperatures. Synchrotron radiation (SR) is a powerful tool for such studies because of its unique time structure. Flashes of X-rays from individual bunches in a storage ring are so short that an object under study does not move more than 1–10 μm during exposure. If a detector is able to store images synchronously with bunches of an SR source the time resolution of such method will be determined by the duration of SR flash from individual bunch. New beam line at the VEPP-4M storage ring will allow to get X-Ray flux from each bunch close to 10{sup 6} photons/channel where channel area is 0.05×0.5 mm{sup 2} and average beam energy is about 30 keV. Bunches in the machine can be grouped into trains with 20 ns time gap. In order to meet these requirements a new detector development was started based on Si microstrip technology. The detector with a new dedicated front-end chip will be able to record images with maximum signal equivalent to 10{sup 6} photons/channel, with signal to noise ratio of ∼10{sup 3}, spatial resolution of 50 μm and maximum frame rate of 50 MHz. The detector has to drive very high peak and average currents without affecting the front-end chip, therefore a specific design of Si sensor should be developed. The front-end chip has to provide signal measurements with the dynamic range of about 10{sup 4} or more and recording of the signal to an analogue memory with the rate of 50 MHz. The concept of such detector is discussed in the paper. The results of the simulations of the main detector parameters and the results of the first measurements with the prototype sensors are presented.

  8. Mathematical framework for fast and rigorous track fit for the ZEUS detector

    Energy Technology Data Exchange (ETDEWEB)

    Spiridonov, Alexander

    2008-12-15

    In this note we present a mathematical framework for a rigorous approach to a common track fit for trackers located in the inner region of the ZEUS detector. The approach makes use of the Kalman filter and offers a rigorous treatment of magnetic field inhomogeneity, multiple scattering and energy loss. We describe mathematical details of the implementation of the Kalman filter technique with a reduced amount of computations for a cylindrical drift chamber, barrel and forward silicon strip detectors and a forward straw drift chamber. Options with homogeneous and inhomogeneous field are discussed. The fitting of tracks in one ZEUS event takes about of 20ms on standard PC. (orig.)

  9. Performance Study of an aSi Flat Panel Detector for Fast Neutron Imaging of Nuclear Waste

    Energy Technology Data Exchange (ETDEWEB)

    Schumann, M.; Mauerhofer, E. [Institute of Energy and Climate Research - Nuclear Waste Management and Reactor Safety, Forschungszentrum Juelich GmbH, 52425 Juelich (Germany); Engels, R.; Kemmerling, G. [Central Institute for Engineering, Electronics and Analytics - Electronic Systems, Forschungszentrum Juelich GmbH, 52425 Juelich (Germany); Frank, M. [MATHCCES - Department of Mathematics, RWTH Aachen University, 52062 Aachen (Germany); Havenith, A.; Kettler, J.; Klapdor-Kleingrothaus, T. [Institute of Nuclear Engineering and Technology Transfer, RWTH Aachen University, 52062 Aachen (Germany); Schitthelm, O. [Corporate Technology, Siemens AG, 91058 Erlangen (Germany)

    2015-07-01

    Radioactive waste must be characterized to check its conformance for intermediate storage and final disposal according to national regulations. For the determination of radio-toxic and chemo-toxic contents of radioactive waste packages non-destructive analytical techniques are preferentially used. Fast neutron imaging is a promising technique to assay large and dense items providing, in complementarity to photon imaging, additional information on the presence of structures in radioactive waste packages. Therefore the feasibility of a compact Neutron Imaging System for Radioactive waste Analysis (NISRA) using 14 MeV neutrons is studied in a cooperation framework of Forschungszentrum Juelich GmbH, RWTH Aachen University and Siemens AG. However due to the low neutron emission of neutron generators in comparison to research reactors the challenging task resides in the development of an imaging detector with a high efficiency, a low sensitivity to gamma radiation and a resolution sufficient for the purpose. The setup is composed of a commercial D-T neutron generator (Genie16GT, Sodern) with a surrounding shielding made of polyethylene, which acts as a collimator and an amorphous silicon flat panel detector (aSi, 40 x 40 cm{sup 2}, XRD-1642, Perkin Elmer). Neutron detection is achieved using a general propose plastic scintillator (EJ-260, Eljen Technology) linked to the detector. The thermal noise of the photodiodes is reduced by employing an entrance window made of aluminium. Optimal gain and integration time for data acquisition are set by measuring the response of the detector to the radiation of a 500 MBq {sup 241}Am-source. Detector performance was studied by recording neutron radiography images of materials with various, but well known, chemical compositions, densities and dimensions (Al, C, Fe, Pb, W, concrete, polyethylene, 5 x 8 x 10 cm{sup 3}). To simulate gamma-ray emitting waste radiographs in presence of a gamma-ray sources ({sup 60}Co, {sup 137}Cs, {sup 241

  10. Cherenkov-type diamond detectors for measurements of fast electrons in the TORE-SUPRA tokamak

    International Nuclear Information System (INIS)

    Jakubowski, L.; Sadowski, M. J.; Zebrowski, J.; Rabinski, M.; Malinowski, K.; Mirowski, R.; Lotte, Ph.; Gunn, J.; Pascal, J-Y.; Colledani, G.; Basiuk, V.; Goniche, M.; Lipa, M.

    2010-01-01

    The paper presents a schematic design and tests of a system applicable for measurements of fast electron pulses emitted from high-temperature plasma generated inside magnetic confinement fusion machines, and particularly in the TORE-SUPRA facility. The diagnostic system based on the registration of the Cherenkov radiation induced by fast electrons within selected solid radiators is considered, and electron low-energy thresholds for different radiators are given. There are some estimates of high thermal loads, which might be deposited by intense electron beams upon parts of the diagnostic equipment within the TORE-SUPRA device. There are some proposed measures to overcome this difficulty by the selection of appropriate absorption filters and Cherenkov radiators, and particularly by the application of a fast-moving reciprocating probe. The paper describes the measuring system, its tests, as well as some results of the preliminary measurements of fast electrons within TORE-SUPRA facility.

  11. Cherenkov-type diamond detectors for measurements of fast electrons in the TORE-SUPRA tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Jakubowski, L.; Sadowski, M. J.; Zebrowski, J.; Rabinski, M.; Malinowski, K.; Mirowski, R. [Andrzej Soltan Institute for Nuclear Studies (IPJ), Otwock-Swierk 05-400 (Poland); Lotte, Ph.; Gunn, J.; Pascal, J-Y.; Colledani, G.; Basiuk, V.; Goniche, M.; Lipa, M. [CEA, IRFM, St Paul-lez-Durance F-13108 (France)

    2010-01-15

    The paper presents a schematic design and tests of a system applicable for measurements of fast electron pulses emitted from high-temperature plasma generated inside magnetic confinement fusion machines, and particularly in the TORE-SUPRA facility. The diagnostic system based on the registration of the Cherenkov radiation induced by fast electrons within selected solid radiators is considered, and electron low-energy thresholds for different radiators are given. There are some estimates of high thermal loads, which might be deposited by intense electron beams upon parts of the diagnostic equipment within the TORE-SUPRA device. There are some proposed measures to overcome this difficulty by the selection of appropriate absorption filters and Cherenkov radiators, and particularly by the application of a fast-moving reciprocating probe. The paper describes the measuring system, its tests, as well as some results of the preliminary measurements of fast electrons within TORE-SUPRA facility.

  12. 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...

  13. High-Rate Fast-Time GRPC for the high eta CMS muon detectors

    CERN Document Server

    Mirabito, Laurent

    2016-01-01

    CMS detector. In their single-gap version we will show that they can stand rates of few ${\\rm kHz/cm}^2$. We also demonstrate that using multi-gap glass RPC, a time resolution of about 60 ps is achieved.

  14. Measurements of fast-neutron-induced signals in silicon pad detectors

    Czech Academy of Sciences Publication Activity Database

    Linhart, V.; Bedajanek, I.; Bém, Pavel; Götz, Miloslav; Honusek, Milan; Pospíšil, S.; Šimečková, Eva

    2006-01-01

    Roč. 563, č. 1 (2006), s. 263-267 ISSN 0168-9002 R&D Projects: GA MPO(CZ) 1H-PK/07 Institutional research plan: CEZ:AV0Z10480505 Keywords : background signals * neutron reactions * solid-state detectors Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 1.185, year: 2006

  15. LHCb: A fast triple-GEM detector for high-rate charged-particle triggering

    CERN Multimedia

    2001-01-01

    - GEM: Principle of Operation - Time Performances - Detector Prototypes and Test Setup - Gas Mixtures - Fields Optimisation - Vgem Optimisation Ar/CO2 (70/30) - Vgem Optimisation Ar/CO2/CF4 (60/20/20) - Time Distributions - Future Tests and Developments

  16. Development of phonon-mediated transition-edge-sensor x-ray detectors for use in astronomy

    Science.gov (United States)

    Leman, Steven W.

    Low temperature detectors have grown in popularity over the years for a variety of reasons. Reduced thermal noise and the associated reduction in statistical fluctuations improve signal to noise. Novel material properties at low temperature such as superconductivity can be exploited. And let us not forget easier access to cryogenic techniques, for example industry made and sold refrigerators eliminating the need for graduate students to make their own. In this thesis I discuss development of a novel phonon-mediated distributed transition-edge-sensor x-ray detector which would be useful for astrophysical studies such as magnetic recombination in the solar corona, the warm-hot intergalactic medium and surveys of clusters and groups of galaxies. The detector uses a large semiconductor absorber and Transition-Edge-Sensors (TESs) to readout the absorbed energy. Calorimetry is performed on individual photons and a partitioning of the energy between various TESs allows for position determination. Hence time varying astronomical sources can be spectroscopically studied and imaged. I will conclude with a discussion of the detector's performance and propose a next generation detector which could make significant improvements on the design discussed in this thesis.

  17. A fast charge coupled device detector for charge exchange recombination spectroscopy on the DIII-D Tokamak

    International Nuclear Information System (INIS)

    Thomas, D.M.; Burrell, K.H.; Groebner, R.J.; Gohil, P.; Kaplan, D.; Makariou, C.; Seraydarian, R.P.

    1997-01-01

    Charge exchange recombination (CER) spectroscopy has become a standard diagnostic for Tokamaks. CER measurements have been used to determine spatially and temporally resolved ion temperature, toroidal and poloidal ion rotation speed, impurity density, and radial electric field. Knowledge of the spatial profile and temporal evolution of the electric field shear in the plasma edge is crucial to understanding the physics of the L to H transition. High speed CER measurements are also valuable for edge localized mode studies. Since the 0.52 ms minimum time resolution of our present system is barely adequate to study the time evolution of these phenomena, we have developed a new charge coupled device (CCD) detector system with about a factor of 2 better time resolution. In addition, our existing system detects sufficient photons to utilize the shortest time resolution only under exceptional conditions. The new CCD detector has a quantum efficiency of about 0.65, which is a factor of 7 better than our previous image intensifier-silicon photodiode detector systems. We have also equipped the new system with spectrometers of lower f/number. This combination should allow more routine operation at the minimum integration time, as well as improving data quality for measurements in the divertor-relevant region outside of the separatrix. Construction details, benchmark data, and initial Tokamak measurements for the new system will be presented. copyright 1997 American Institute of Physics

  18. Analysis of transition to fuel cycle system with continuous recycling in fast and thermal reactors - 5060

    International Nuclear Information System (INIS)

    Passereini, S.; Feng, B.; Fei, T.; Kim, T.K.; Taiwo, T.A.; Brown, N.R.; Cuadra, A.

    2015-01-01

    A recent Evaluation and Screening study of nuclear fuel cycle options identified a few groups of options as most promising. One of these most promising Evaluation Groups (EGs) is characterized by the continuous recycling of uranium (U) and transuranics (TRU) with natural uranium feed in both fast and thermal critical reactors. This evaluation group, designated as EG30, is represented by an example fuel cycle option that employs a two-technology, two-stage fuel cycle system. The first stage involves the continuous recycling of co-extracted U/TRU in Sodium-cooled Fast Reactors (SFRs) with metallic fuel and breeding ratio greater than 1. The second stage involves the use of the surplus TRU in Mixed Oxide (MOX) fuel in Pressurized Water Reactors that are MOX-capable (MOX-PWRs). This paper presents and discusses preliminary fuel cycle analysis results from the fuel cycle codes VISION and DYMOND for the transition to this fuel cycle option from the current once-through cycle in the United States (U.S.) that consists of Light Water Reactors (LWRs) that only use conventional UO 2 fuel. The analyses in this paper are applicable for a constant 100 GWe capacity, roughly the size of the U.S. nuclear fleet. Two main strategies for the transition to EG30 were analyzed: 1) deploying both SFRs and MOX-PWRs in parallel or 2) deploying them in series with the SFR fleet first. With an estimated retirement schedule for the existing LWRs, an assumed reactor lifetime of 60 years, and no growth, the nuclear system fully transitions to the new fuel cycle within 100 years for both strategies without SFR fuel shortages. Compared to the once-through cycle, transition to the SFR/MOX-PWR fleet with continuous recycle was shown to offer significant reductions in uranium consumption and waste disposal requirements. In addition, these initial calculations revealed a few notable modeling and strategy questions regarding how recycled resources are allocated, reactors that can switch between

  19. Fast flux measurements by means of threshold detectors on the reactor 'Melusine'

    International Nuclear Information System (INIS)

    Leger, P.; Sautiez, B.

    1959-01-01

    Using existing data on the (n,p) and (n,α) threshold reactions we have carried out fast flux measurements on the swimming pool type reactor 'Melusine'. Four common elements: P, S, Mg, Al were chosen because from the point of view of fast spectrum analysis they represent a fairly good energy range from 2.4 MeV to 8 MeV. The fission flux value found in the central element at a power of 1 MW is 1.4 x 10 13 n/cm 2 /s ± 0.14. (author) [fr

  20. Micro-channel plate detector for ultra-fast relativistic electron diffraction

    International Nuclear Information System (INIS)

    Musumeci, P.; Moody, J.T.; Scoby, C.M.; Gutierrez, M.S.; Bender, H.A.; Hilko, B.; Kruschwitz, C.A.; Wilcox, N.S.

    2011-01-01

    Using relativistic ultra-short electron beams to obtain single-shot diffraction patterns holds the promise to yield real-time resolution of atomic motion in an easily accessible environment, such as a university laboratory, at a fraction of the cost of fourth-generation X-ray sources. One of the main issues in bringing this technique to full maturity is the development of efficient detector systems to record the diffraction pattern using a few MeV electron beams. Low noise, high spatial resolution, and single-electron detection capability are all characteristics of an ideal detector. In this paper, we compare the performances of a traditional fluorescent phosphor screen with a detection system based on the micro-channel plate (MCP). Since MCPs are typically used with lower energy electron beams, these tests constitute one of the few experimental data points available on the use of these devices with MeV energy beams.

  1. Micro-channel plate detector for ultra-fast relativistic electron diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Musumeci, P., E-mail: musumeci@physics.ucla.edu [UCLA Department of Physics and Astronomy, 475 Portola Plaza, Los Angeles, CA, 90095-1547 (United States); Moody, J.T.; Scoby, C.M.; Gutierrez, M.S. [UCLA Department of Physics and Astronomy, 475 Portola Plaza, Los Angeles, CA, 90095-1547 (United States); Bender, H.A.; Hilko, B.; Kruschwitz, C.A.; Wilcox, N.S. [National Security Technologies, LLC, Los Alamos Operations, Los Alamos, NM (United States)

    2011-05-01

    Using relativistic ultra-short electron beams to obtain single-shot diffraction patterns holds the promise to yield real-time resolution of atomic motion in an easily accessible environment, such as a university laboratory, at a fraction of the cost of fourth-generation X-ray sources. One of the main issues in bringing this technique to full maturity is the development of efficient detector systems to record the diffraction pattern using a few MeV electron beams. Low noise, high spatial resolution, and single-electron detection capability are all characteristics of an ideal detector. In this paper, we compare the performances of a traditional fluorescent phosphor screen with a detection system based on the micro-channel plate (MCP). Since MCPs are typically used with lower energy electron beams, these tests constitute one of the few experimental data points available on the use of these devices with MeV energy beams.

  2. Development of a bioaerosol single particle detector (BIO IN) for the fast ice nucleus chamber FINCH

    Science.gov (United States)

    Bundke, U.; Reimann, B.; Nillius, B.; Jaenicke, R.; Bingemer, H.

    2009-10-01

    In this work we present the setup and first tests of our new BIO IN detector. This detector is designed to classify atmospheric ice nuclei (IN) for their biological content. Biological material is identified via its auto-fluorescence (intrinsic fluorescence) after irradiation with UV radiation. Ice nuclei are key substances for precipitation development via the Bergeron-Findeisen process. The level of scientific knowledge regarding origin and climatology (temporal and spatial distribution) of IN is very low. Some biological material is known to be active as IN even at relatively high temperatures of up to -2°C (e.g. pseudomonas syringae bacteria). These biological IN could have a strong influence on the formation of clouds and precipitation. We have designed the new BIO IN sensor to analyze the abundance of IN of biological origin. The instrument will be flown on one of the first missions of the new German research aircraft ''HALO'' (High Altitude and LOng Range).

  3. Connection between slow and fast dynamics of molecular liquids around the glass transition

    International Nuclear Information System (INIS)

    Niss, Kristine; Dalle-Ferrier, Cecile; Frick, Bernhard; Russo, Daniela; Dyre, Jeppe; Alba-Simionesco, Christiane

    2010-01-01

    The mean-square displacement (MSD) was measured by neutron scattering at various temperatures and pressures for a number of molecular glass-forming liquids. The MSD is invariant along the glass-transition line at the pressure studied, thus establishing an 'intrinsic' Lindemann criterion for any given liquid. A one-to-one connection between the MSD's temperature dependence and the liquid's fragility is found when the MSD is evaluated on a time scale of ∼4 ns, but does not hold when the MSD is evaluated at shorter times. The findings are discussed in terms of the elastic model and the role of relaxations, and the correlations between slow and fast dynamics are addressed.

  4. Test of a position-sensitive photomultiplier for fast scintillating fiber detector read-out

    International Nuclear Information System (INIS)

    Baehr, J.; Hoffmann, B.; Luedecke, H.; Nahnhauer, R.; Pohl, M.; Roloff, H.E.

    1993-01-01

    A position-sensitive photomultiplier with 256 anode pixels has been used to read out scintillating fibers excited by light emitting diodes, electrons from a β-source and a 5 GeV electron beam. Measurements have been done within a magnetic field up to 0.6 T. Tracking and electromagnetic shower detection capabilities of a simple fiber detector have been studied. (orig.)

  5. Fast photoconductor CdTe detectors for synchrotron x-ray studies

    International Nuclear Information System (INIS)

    Yoo, Sung Shik; Faurie, J.P.; Huang Qiang; Rodricks, B.

    1993-09-01

    The Advanced Photon Source will be that brightest source of synchrotron x-rays when it becomes operational in 1996. During normal operation, the ring will be filled with 20 bunches of positrons with an interbunch spacing of 177 ns and a bunch width of 119 ps. To perform experiments with x-rays generated by positrons on these time scales one needs extremely high speed detectors. To achieve the necessary high speed, we are developing MBE-grown CdTe-base photoconductive position sensitive array detectors. The arrays fabricated have 64 pixels with a gap of 100 μm between pixels. The high speed response of the devices was tested using a short pulse laser. X-ray static measurements were performed using an x-ray tube and synchrotron radiation to study the device's response to flux and wavelength changes. This paper presents the response of the devices to some of these tests and discusses different physics aspects to be considered when designing high speed detectors

  6. Pulse shaping for fast coincidence with NaI(Tl) detectors

    International Nuclear Information System (INIS)

    Bose, S.; Sinha, B.K.; Bhattacharya, R.

    1983-01-01

    The effect of multiple limiting of the anode pulses of the photomultiplier tubes on the resolving time of an NaI(Tl)-NaI(Tl) fast coincidence set up is investigated with the help of a simple transistored limiter circuit. The performance of the set up for different energy ranges selected in the side channels is also investigated. (orig.)

  7. A large area transition radiation detector to measure the energy of muons in the Gran Sasso underground laboratory

    International Nuclear Information System (INIS)

    Barbarito, E.; Bellotti, R.; Cafagna, F.; Castellano, M.; De Cataldo, G.; De Marzo, C.; Favuzzi, C.; Fusco, P.; Giglietto, N.; Guarnaccia, P.; Mazziotta, M.N.; Mongelli, M.; Montaruli, T.; Perchiazzi, M.; Raino, A.; Sacchetti, A.; Spinelli, P.

    1995-01-01

    We have designed and built a transition radiation detector of 36 m 2 area in order to measure the residual energy of muons penetrating in the Gran Sasso cosmic ray underground laboratory up to the TeV region. It consists of three adjacent modules, each of 2x6 m 2 area. Polystyrene square tubes, filled with a argon-carbon dioxide gas mixture, and polyethylene foam layers are used as proportional detectors and radiators respectively. We cover such a large surface with only 960 channels that provide adequate energy resolution and particle tracking for the astroparticle physics items to investigate. The detector has been calibrated using a reduced size prototype in a test beam. Results from one module exposed to cosmic rays at sea level are shown. (orig.)

  8. High rate particle tracking and ultra-fast timing with a thin hybrid silicon pixel detector

    Science.gov (United States)

    Fiorini, M.; Aglieri Rinella, G.; Carassiti, V.; Ceccucci, A.; Cortina Gil, E.; Cotta Ramusino, A.; Dellacasa, G.; Garbolino, S.; Jarron, P.; Kaplon, J.; Kluge, A.; Marchetto, F.; Mapelli, A.; Martin, E.; Mazza, G.; Morel, M.; Noy, M.; Nuessle, G.; Perktold, L.; Petagna, P.; Petrucci, F.; Poltorak, K.; Riedler, P.; Rivetti, A.; Statera, M.; Velghe, B.

    2013-08-01

    The Gigatracker (GTK) is a hybrid silicon pixel detector designed for the NA62 experiment at CERN. The beam spectrometer, made of three GTK stations, has to sustain high and non-uniform particle rate (∼ 1 GHz in total) and measure momentum and angles of each beam track with a combined time resolution of 150 ps. In order to reduce multiple scattering and hadronic interactions of beam particles, the material budget of a single GTK station has been fixed to 0.5% X0. The expected fluence for 100 days of running is 2 ×1014 1 MeV neq /cm2, comparable to the one foreseen in the inner trackers of LHC detectors during 10 years of operation. To comply with these requirements, an efficient and very low-mass (< 0.15 %X0) cooling system is being constructed, using a novel microchannel cooling silicon plate. Two complementary read-out architectures have been produced as small-scale prototypes: one is based on a Time-over-Threshold circuit followed by a TDC shared by a group of pixels, while the other makes use of a constant-fraction discriminator followed by an on-pixel TDC. The read-out ASICs are produced in 130 nm IBM CMOS technology and will be thinned down to 100 μm or less. An overview of the Gigatracker detector system will be presented. Experimental results from laboratory and beam tests of prototype bump-bonded assemblies will be described as well. These results show a time resolution of about 170 ps for single hits from minimum ionizing particles, using 200 μm thick silicon sensors.

  9. A Monte Carlo Model for Neutron Coincidence Counting with Fast Organic Liquid Scintillation Detectors

    International Nuclear Information System (INIS)

    Gamage, Kelum A.A.; Joyce, Malcolm J.; Cave, Frank D.

    2013-06-01

    Neutron coincidence counting is an established, nondestructive method for the qualitative and quantitative analysis of nuclear materials. Several even-numbered nuclei of the actinide isotopes, and especially even-numbered plutonium isotopes, undergo spontaneous fission, resulting in the emission of neutrons which are correlated in time. The characteristics of this i.e. the multiplicity can be used to identify each isotope in question. Similarly, the corresponding characteristics of isotopes that are susceptible to stimulated fission are somewhat isotope-related, and also dependent on the energy of the incident neutron that stimulates the fission event, and this can hence be used to identify and quantify isotopes also. Most of the neutron coincidence counters currently used are based on 3 He gas tubes. In the 3 He-filled gas proportional-counter, the (n, p) reaction is largely responsible for the detection of slow neutrons and hence neutrons have to be slowed down to thermal energies. As a result, moderator and shielding materials are essential components of many systems designed to assess quantities of fissile materials. The use of a moderator, however, extends the die-away time of the detector necessitating a larger coincidence window and, further, 3 He is now in short supply and expensive. In this paper, a simulation based on the Monte Carlo method is described which has been performed using MCNPX 2.6.0, to model the geometry of a sector-shaped liquid scintillation detector in response to coincident neutron events. The detection of neutrons from a mixed-oxide (MOX) fuel pellet using an organic liquid scintillator has been simulated for different thicknesses of scintillators. In this new neutron detector, a layer of lead has been used to reduce the gamma-ray fluence reaching the scintillator. The effect of lead for neutron detection has also been estimated by considering different thicknesses of lead layers. (authors)

  10. On the electron density localization in elemental cubic ceramic and FCC transition metals by means of a localized electrons detector.

    Science.gov (United States)

    Aray, Yosslen; Paredes, Ricardo; Álvarez, Luis Javier; Martiz, Alejandro

    2017-06-14

    The electron density localization in insulator and semiconductor elemental cubic materials with diamond structure, carbon, silicon, germanium, and tin, and good metallic conductors with face centered cubic structure such as α-Co, Ni, Cu, Rh, Pd, Ag, Ir, Pt, and Au, was studied using a localized electrons detector defined in the local moment representation. Our results clearly show an opposite pattern of the electron density localization for the cubic ceramic and transition metal materials. It was found that, for the elemental ceramic materials, the zone of low electron localization is very small and is mainly localized on the atomic basin edges. On the contrary, for the transition metals, there are low-valued localized electrons detector isocontours defining a zone of highly delocalized electrons that extends throughout the material. We have found that the best conductors are those in which the electron density at this low-value zone is the lowest.

  11. Mapping and uncertainty analysis of energy and pitch angle phase space in the DIII-D fast ion loss detector.

    Science.gov (United States)

    Pace, D C; Pipes, R; Fisher, R K; Van Zeeland, M A

    2014-11-01

    New phase space mapping and uncertainty analysis of energetic ion loss data in the DIII-D tokamak provides experimental results that serve as valuable constraints in first-principles simulations of energetic ion transport. Beam ion losses are measured by the fast ion loss detector (FILD) diagnostic system consisting of two magnetic spectrometers placed independently along the outer wall. Monte Carlo simulations of mono-energetic and single-pitch ions reaching the FILDs are used to determine the expected uncertainty in the measurements. Modeling shows that the variation in gyrophase of 80 keV beam ions at the FILD aperture can produce an apparent measured energy signature spanning across 50-140 keV. These calculations compare favorably with experiments in which neutral beam prompt loss provides a well known energy and pitch distribution.

  12. A method for the measurement of fission rates in fast neutron fields using solid state track detectors

    International Nuclear Information System (INIS)

    Hansen, W.; Vogel, W.

    1984-04-01

    Solid state track detectors (SSTDs) are increasingly used for the registration of radiation in different fields of nuclear physics. Because of their small sizes and masses and the absence of any electronics during exposure SSTDs do not cause distortions in the system to be investigated and are useful for measurements at such places being difficult of access. The elaboration of a method is described for fission rate measurements in fast neutron fields applying SSTDs and different fissionable isotopes which were electrodeposited on stainless steel backings. Experiences of the electrodeposition and results of quality checks are presented. The evaluation of the etched tracks is performed with spark counter technique. The dependence of the counting result on essential influence parameters is discussed. (author)

  13. Mapping and uncertainty analysis of energy and pitch angle phase space in the DIII-D fast ion loss detector

    Energy Technology Data Exchange (ETDEWEB)

    Pace, D. C., E-mail: pacedc@fusion.gat.com; Fisher, R. K.; Van Zeeland, M. A. [General Atomics, PO Box 85608, San Diego, California 92186-5608 (United States); Pipes, R. [Department of Physics, University of Hawaii, Hilo, Hawaii 96720-4091 (United States)

    2014-11-15

    New phase space mapping and uncertainty analysis of energetic ion loss data in the DIII-D tokamak provides experimental results that serve as valuable constraints in first-principles simulations of energetic ion transport. Beam ion losses are measured by the fast ion loss detector (FILD) diagnostic system consisting of two magnetic spectrometers placed independently along the outer wall. Monte Carlo simulations of mono-energetic and single-pitch ions reaching the FILDs are used to determine the expected uncertainty in the measurements. Modeling shows that the variation in gyrophase of 80 keV beam ions at the FILD aperture can produce an apparent measured energy signature spanning across 50-140 keV. These calculations compare favorably with experiments in which neutral beam prompt loss provides a well known energy and pitch distribution.

  14. A fast large dynamic range shaping amplifier for particle detector front-end

    International Nuclear Information System (INIS)

    Rivetti, Angelo; Delaurenti, Paolo

    2007-01-01

    The paper describes a fast shaping amplifier with rail-to-rail output swing. The circuit is based on a CMOS operational amplifier with a class AB output stage. A baseline holder, incorporating a closed-loop unity gain buffer with slew rate limitation, performs the AC coupling with the preamplifier and guarantees a baseline shift smaller than 3 mV for unipolar output pulses of 3 V and 10 MHz rate

  15. A fast and pragmatic approach for scatter correction in flat-detector CT using elliptic modeling and iterative optimization

    Science.gov (United States)

    Meyer, Michael; Kalender, Willi A.; Kyriakou, Yiannis

    2010-01-01

    Scattered radiation is a major source of artifacts in flat detector computed tomography (FDCT) due to the increased irradiated volumes. We propose a fast projection-based algorithm for correction of scatter artifacts. The presented algorithm combines a convolution method to determine the spatial distribution of the scatter intensity distribution with an object-size-dependent scaling of the scatter intensity distributions using a priori information generated by Monte Carlo simulations. A projection-based (PBSE) and an image-based (IBSE) strategy for size estimation of the scanned object are presented. Both strategies provide good correction and comparable results; the faster PBSE strategy is recommended. Even with such a fast and simple algorithm that in the PBSE variant does not rely on reconstructed volumes or scatter measurements, it is possible to provide a reasonable scatter correction even for truncated scans. For both simulations and measurements, scatter artifacts were significantly reduced and the algorithm showed stable behavior in the z-direction. For simulated voxelized head, hip and thorax phantoms, a figure of merit Q of 0.82, 0.76 and 0.77 was reached, respectively (Q = 0 for uncorrected, Q = 1 for ideal). For a water phantom with 15 cm diameter, for example, a cupping reduction from 10.8% down to 2.1% was achieved. The performance of the correction method has limitations in the case of measurements using non-ideal detectors, intensity calibration, etc. An iterative approach to overcome most of these limitations was proposed. This approach is based on root finding of a cupping metric and may be useful for other scatter correction methods as well. By this optimization, cupping of the measured water phantom was further reduced down to 0.9%. The algorithm was evaluated on a commercial system including truncated and non-homogeneous clinically relevant objects.

  16. Fast Monte Carlo-simulator with full collimator and detector response modelling for SPECT

    International Nuclear Information System (INIS)

    Sohlberg, A.O.; Kajaste, M.T.

    2012-01-01

    Monte Carlo (MC)-simulations have proved to be a valuable tool in studying single photon emission computed tomography (SPECT)-reconstruction algorithms. Despite their popularity, the use of Monte Carlo-simulations is still often limited by their large computation demand. This is especially true in situations where full collimator and detector modelling with septal penetration, scatter and X-ray fluorescence needs to be included. This paper presents a rapid and simple MC-simulator, which can effectively reduce the computation times. The simulator was built on the convolution-based forced detection principle, which can markedly lower the number of simulated photons. Full collimator and detector response look-up tables are pre-simulated and then later used in the actual MC-simulations to model the system response. The developed simulator was validated by comparing it against 123 I point source measurements made with a clinical gamma camera system and against 99m Tc software phantom simulations made with the SIMIND MC-package. The results showed good agreement between the new simulator, measurements and the SIMIND-package. The new simulator provided near noise-free projection data in approximately 1.5 min per projection with 99m Tc, which was less than one-tenth of SIMIND's time. The developed MC-simulator can markedly decrease the simulation time without sacrificing image quality. (author)

  17. Fast front-end electronics for semiconductor tracking detectors: Trends and perspectives

    Energy Technology Data Exchange (ETDEWEB)

    Rivetti, Angelo

    2014-11-21

    In the past few years, extensive research efforts pursued by both the industry and the academia have lead to major improvements in the performance of Analog to Digital Converters (ADCs) and Time to Digital Converters (TDCs). ADCs achieving 8–10 bit resolution, 50–100 MHz conversion frequency and less than 1 mW power consumption are the today's standard, while TDCs have reached sub-picosecond time resolution. These results have been made possible by architectural upgrades combined with the use of ultra deep submicron CMOS technologies with minimum feature size of 130 nm or smaller. Front-end ASICs in which a prompt digitization is followed by signal conditioning in the digital domain can now be envisaged also within the tight power budget typically available in high density tracking systems. Furthermore, tracking detectors embedding high resolution timing capabilities are gaining interest. In the paper, ADC's and TDC's developments which are of particular relevance for the design front-end electronics for semiconductor trackers are discussed along with the benefits and challenges of exploiting such high performance building blocks in implementing the next generation of ASICs for high granularity particle detectors.

  18. Fast neutron irradiation effects on CR-39 nuclear track detector for dosimetric applications

    International Nuclear Information System (INIS)

    Kader, M.H.

    2005-01-01

    The effect of neutron irradiation on the dosimetric properties of CR-39 solid-state nuclear track detector have been investigated. CR-39 samples were irradiated with neutrons of energies follow a Maxwellian distribution centered about 2 MeV. These samples were irradiated with different doses in the range 0.1-1 Sv. The background and track density were measured as a function of etching time. In addition, the dependence of sensitivity of CR-39 detector on the neutrons dose has been investigated. The results show that the Sensitivity started to increase at 0.4 Sv neutrons dose, so this sample were chosen to be a subject for further study to investigate the effect of gamma dose on its properties. The sample irradiated with 0.4 Sv were exposed to different doses of gamma rays at levels between 10 and 80 kGy. The effect of gamma doses on the bulk etching rate VB, the track diameter and the sensitivity of the CR-39 samples was investigated. The results show that the dosimetric properties of CR-39 SSNTD are greatly affected by both neutron and gamma irradiation

  19. Development of Fast High-Resolution Muon Drift-Tube Detectors for High Counting Rates

    CERN Document Server

    INSPIRE-00287945; Dubbert, J.; Horvat, S.; Kortner, O.; Kroha, H.; Legger, F.; Richter, R.; Adomeit, S.; Biebel, O.; Engl, A.; Hertenberger, R.; Rauscher, F.; Zibell, A.

    2011-01-01

    Pressurized drift-tube chambers are e?cient detectors for high-precision tracking over large areas. The Monitored Drift-Tube (MDT) chambers of the muon spectrometer of the ATLAS detector at the Large Hadron Collider (LHC) reach a spatial resolution of 35 micons and almost 100% tracking e?ciency with 6 layers of 30 mm diameter drift tubes operated with Ar:CO2 (93:7) gas mixture at 3 bar and a gas gain of 20000. The ATLAS MDT chambers are designed to cope with background counting rates due to neutrons and gamma-rays of up to about 300 kHz per tube which will be exceeded for LHC luminosities larger than the design value of 10-34 per square cm and second. Decreasing the drift-tube diameter to 15 mm while keeping the other parameters, including the gas gain, unchanged reduces the maximum drift time from about 700 ns to 200 ns and the drift-tube occupancy by a factor of 7. New drift-tube chambers for the endcap regions of the ATLAS muon spectrometer have been designed. A prototype chamber consisting of 12 times 8 l...

  20. 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.

  1. Position, Energy, and Transit Time Distributions in a Hemispherical Deflector Analyzer with Position Sensitive Detector

    Directory of Open Access Journals (Sweden)

    Omer Sise

    2015-01-01

    Full Text Available Practical analytic equations, for the ideal field, and numerical results from SIMION simulations, for the fringing field, are presented for the exit radius rπ and transit time tπ of electrons in a hemispherical deflector analyzer (HDA over a wide range of analyzer parameters. Results are presented for a typically dimensioned HDA with mean radius R-=101.6 mm and interradial separation ΔR=R2-R1=58.4 mm able to accommodate a 40 mm diameter position sensitive detector (PSD. Results for three different entry positions R0 are compared: R0=R- (the conventional central entry and two displaced (paracentric entries: R0=82.55 mm and R0=116 mm. Exit spreads Δrπ, Δtπ and base energy resolution ΔEB are computed for HDA pass energies E0=10, 100, 500, and 1000 eV, entry aperture sizes Δr0≤1.5 mm, entry angular spreads |αmax|≤5°, and an electron beam with relative energy spread δE/E0≤0.4%. Overall, under realistic conditions, both paracentric entries demonstrate near ideal field behavior and clear superiority over the conventional entry at R0=R-. The R0=82.55 mm entry has better absolute energy and time spread resolutions, while the R0=116 mm has better relative energy resolutions, both offering attractive alternatives for time-of-flight and coincidence applications where both energy and timing resolutions are important.

  2. A fast track trigger processor for the OPAL detector at LEP

    International Nuclear Information System (INIS)

    Carter, A.A.; Jaroslawski, S.; Wagner, A.

    1986-01-01

    A fast hardware track trigger processor being built for the OPAL experiment is described. The processor will analyse data from the central drift chambers of OPAL to determine whether any tracks come from the interaction region, and thereby eliminate background events. The processor will find tracks over a large angular range, vertical strokecos thetavertical stroke < or approx. 0.95. The design of the processor is described, together with a brief account of its hardware implementation for OPAL. The results of feasibility studies are also presented. (orig.)

  3. NeuLAND MRPC-based detector prototypes tested with fast neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Caesar, C., E-mail: c.caesar@gsi.de [GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany); Aumann, T. [GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany); Bemmerer, D. [Forschungszentrum Dresden-Rossendorf, Dresden (Germany); Boretzky, K. [GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany); Elekes, Z. [Forschungszentrum Dresden-Rossendorf, Dresden (Germany); ATOMKI, Debrecen (Hungary); Gonzalez-Diaz, D.; Hehner, J.; Heil, M. [GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany); Kempe, M. [Forschungszentrum Dresden-Rossendorf, Dresden (Germany); Maroussov, V. [Universitaet zu Koeln, Koeln (Germany); Nusair, O. [GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany); Al-Balqa Applied University, Salt (Jordan); Reifarth, R.; Rossi, D.; Simon, H. [GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany); Stach, D.; Wagner, A.; Yakorev, D. [Forschungszentrum Dresden-Rossendorf, Dresden (Germany); Zilges, A. [ATOMKI, Debrecen (Hungary)

    2012-01-01

    Recent results from a first irradiation of multi-gap resistive plate chambers with fast neutrons are presented. The counters have been built at GSI and FZD. The experiment was performed at the 'The Svedberg Laboratory' (TSL) in Uppsala, Sweden, utilizing a quasi-monoenergetic neutron beam with an energy E{sub n}=175 MeV. For a 2 Multiplication-Sign 4 gap prototype operated at E=100 kV/cm, an efficiency of (0.77 {+-}0.33)% was measured.

  4. CdTe in photoconductive applications. Fast detector for metrology and X-ray imaging

    International Nuclear Information System (INIS)

    Cuzin, M.

    1991-01-01

    Operating as a photoconductor, the sensitivity and the impulse response of semi-insulating materials greatly depend on the excitation duration compared to electron and hole lifetimes. The requirement of ohmic contact is shortly discussed. Before developing picosecond measurements with integrated autocorrelation system, this paper explains high energy industrial tomographic application with large CdTe detectors (25x15x0.9 mm 3 ). The excitation is typically μs range. X-ray flash radiography, with 10 ns burst, is in an intermediate time domain where excitation is similar to electron life-time. In laser fusion experiment excitation is in the range of 50 ps and we develop photoconductive devices able to study very high speed X-ray emission time behaviour. Thin polycristalline MOCVD CdTe films with picosecond response are suitable to perform optical correlation measurements of single shot pulses with a very large bandwidth (- 50 GHz)

  5. FAST

    DEFF Research Database (Denmark)

    Zuidmeer-Jongejan, Laurian; Fernandez-Rivas, Montserrat; Poulsen, Lars K.

    2012-01-01

    ABSTRACT: The FAST project (Food Allergy Specific Immunotherapy) aims at the development of safe and effective treatment of food allergies, targeting prevalent, persistent and severe allergy to fish and peach. Classical allergen-specific immunotherapy (SIT), using subcutaneous injections with aqu...

  6. Transition radiation detector of the experience NOMAD for the τ identification in the channel: τ- → e-ν-bare ντ

    International Nuclear Information System (INIS)

    Fazio, T.

    1995-01-01

    This thesis presents a work included in an experiment of research concerning neutrino oscillations in the channel ν μ → ν τ at CERN (NOMAD-WA96). This experiments need several detectors, and particularly a transition radiation detector with specific characteristics. The work consists, in a first part, in the study of neutrino physic and of the NOMAD detector. In a second part, the report presents how was implemented the transition radiation detector and how works the simulation of a such radiation. Then, the detector is optimised by comparing experiments and simulations; the thesis also presents how to control the detector. The last part talks about algorithms of pions-electrons separation. (TEC). 95 refs., 78 figs., 12 tabs

  7. Measurement of energy transitions for the decay radiations of 75Ge and 69Ge in a high purity germanium detector

    Science.gov (United States)

    Aydın, Güral; Usta, Metin; Oktay, Adem

    2018-06-01

    Photoactivation experiments have a wide range of application areas in nuclear, particle physics, and medical physics such as measuring energy levels and half-lifes of nuclei, experiments for understanding imaging methods in medicine, isotope production for patient treatment, radiation security and transportation, radiation therapy, and astrophysics processes. In this study, some energy transition values of the decay radiations of 75Ge and 69Ge, which are the products of photonuclear reactions (γ, n) with germanium isotopes (75Ge and 69Ge), were measured. The gamma spectrum as a result of atomic transitions were analysed by using a high purity semiconductor germanium detector and the energy transition values which are presented here were compared with the ones which are the best in literature. It was observed that the results presented are in agreement with literature in error range and some results have better precisions.

  8. A combined analysis technique for the search for fast magnetic monopoles with the MACRO detector

    CERN Document Server

    Ambrosio, M; Auriemma, G; Bakari, D; Baldini, A; Barbarino, G C; Barish, B C; Battistoni, G; Becherini, Y; Bellotti, R; Bemporad, C; Bernardini, P; Bilokon, H; Bloise, C; Bower, C; Brigida, M; Bussino, S; Cafagna, F; Calicchio, M; Campana, D; Carboni, M; Caruso, R; Cecchini, S; Cei, F; Chiarella, V; Choudhary, B C; Coutu, S; De Cataldo, G; Dekhissi, H; De Marzo, C; De Mitri, I; Derkaoui, J E; De Vincenzi, M; Di Credico, A; Erriquez, O; Favuzzi, C; Forti, C; Fusco, P; Giacomelli, G; Giannini, G; Giglietto, N; Giorgini, M; Grassi, M; Grillo, A; Guarino, F; Gustavino, C; Habig, A; Heinz, R; Iarocci, E; Katsavounidis, E; Katsavounidis, I; Kearns, E; Kim, H; Kyriazopoulou, S; Lamanna, E; Lane, C; Levin, D S; Lipari, P; Longley, N P; Longo, M J; Loparco, F; Maaroufi, F; Mancarella, G; Mandrioli, G; Manzoor, S; Margiotta, A; Marini, A; Martello, D; Marzari-Chiesa, A; Mazziotta, M N; Michael, D G; Monacelli, P; Montaruli, T; Monteno, M; Mufson, S L; Musser, J; Nicolò, D; Nolty, R; Orth, C; Osteria, G; Palamara, O; Patera, V; Patrizii, L; Pazzi, R; Peck, C W; Perrone, L; Petrera, S; Popa, V; Reynoldson, J; Ronga, F; Rrhioua, A; Satriano, C; Scapparone, E; Scholberg, K; Sciubba, A; Serra, P; Sioli, M; Sirri, G; Sitta, M; Spinelli, P; Spinetti, M; Spurio, M; Steinberg, R; Stone, J L; Sulak, L R; Surdo, A; Tarle, G; Togo, V; Vakili, M; Walter, C W; Webb, R

    2002-01-01

    We describe a search method for fast moving ( beta = v/c > 5 * 10/sup -3/) magnetic monopoles using simultaneously the scintillator, streamer tube and track-etch subdetectors of the MACRO apparatus. The first two subdetectors are used primarily for the identification of candidates while the track-etch one is used as the final tool for their rejection or confirmation. Using this technique, a first sample of more than two years of data has been analyzed without any evidence of a magnetic monopole. We set a 90% CL upper limit to the local monopole flux of 1.5 * 10/sup -15/ cm/sup -2/s/sup -1/sr/sup -1/ in the velocity range 5 * 10/sup -3/

  9. Performance of the AMBFTK board for the FastTracker processor for the ATLAS detector upgrade

    International Nuclear Information System (INIS)

    Alberti, F; Citterio, M; Liberali, V; Meroni, C; Andreani, A; Stabile, A; Annovi, A; Beretta, M; Crescioli, F; Dell'Orso, M; Piendibene, M; Volpi, G; Giannetti, P; Lanza, A; Magalotti, D; Sacco, I

    2013-01-01

    Modern experiments at hadron colliders search for extremely rare processes hidden in a very large background. As the experiment complexity and the accelerator backgrounds and luminosity increase we need increasingly complex and exclusive selections. The FastTracker (FTK) processor for the ATLAS experiment offers extremely powerful, very compact and low power consumption processing units for the future, which is essential for increased efficiency and purity in the Level 2 trigger selection through the intensive use of tracking. Pattern recognition is performed with Associative Memories (AM). The AMBFTK board and the AMchip04 integrated circuit have been designed specifically for this purpose. We report on the preliminary test results of the first prototypes of the AMBFTK board and of the AMchip04.

  10. IODA - a fast, automated and flexible system for ion track analysis on film detectors

    International Nuclear Information System (INIS)

    Guth, H.; Hellmann, A.

    1995-02-01

    The IODA System (Ion Density Analysis) is used to analyse detector films, resulting from experiments at the pulse power generator KALIF (Karlsruhe Light Ion Facility). The system consists of evaluation software and a microcomputer, which controls a microscope, a video interface, and a multiprocessor subsystem. The segmentation of ion tracks is done automatically by means of digital image processing and pattern recognition. After defining an evaluation range and selecting a suitable analysis method, the film is scanned by the microscope for counting the impacts of the underlying image. According to the appearance of the ion tracks on the film, different methods can be selected. The evaluation results representing the ion density are stored in a matrix. The time needed for an evaluation at a high resolution can be shortened by shipping time consuming pattern recognition calculations to the multiprocessor subsystem. The bottlenecks of the system are the data transfer and the speed of the microscope stage. Simple handling of the system even on alphanumeric terminals had been an important design issue. This was implemented by a logically structured menue system including online help features. This report can be used a s a manual to support the user with system operation. (orig.) [de

  11. Development of an ultra-fast X-ray camera using hybrid pixel detectors

    International Nuclear Information System (INIS)

    Dawiec, A.

    2011-05-01

    The aim of the project whose work described in this thesis is part, was to design a high-speed X-ray camera using hybrid pixels applied to biomedical imaging and for material science. As a matter of fact the hybrid pixel technology meets the requirements of these two research fields, particularly by providing energy selection and low dose imaging capabilities. In this thesis, high frame rate X-ray imaging based on the XPAD3-S photons counting chip is presented. Within a collaboration between CPPM, ESRF and SOLEIL, three XPAD3 cameras were built. Two of them are being operated at the beamline of the ESRF and SOLEIL synchrotron facilities and the third one is embedded in the PIXSCAN II irradiation setup of CPPM. The XPAD3 camera is a large surface X-ray detector composed of eight detection modules of seven XPAD3-S chips each with a high-speed data acquisition system. The readout architecture of the camera is based on the PCI Express interface and on programmable FPGA chips. The camera achieves a readout speed of 240 images/s, with maximum number of images limited by the RAM memory of the acquisition PC. The performance of the device was characterized by carrying out several high speed imaging experiments using the PIXSCAN II irradiation setup described in the last chapter of this thesis. (author)

  12. CHANTI: a fast and efficient charged particle veto detector for the NA62 experiment at cern

    CERN Document Server

    Mirra, Marco

    This work has been performed into the frame of the NA62 experiment at CERN that aims at measuring the Branching-Ratio of the ultra-rare kaon decay K+→π+ nu nubar with 10% uncertainty - using an unseparated kaon beam of 75GeV/c - in order to test the Standard Model (SM), to look for physics beyond SM and to measure the |Vtd| element of the Cabibbo-Kobayashi-Maskawa (CKM) flavor mixing matrix. Backgrounds, which are up to 10^10 times higher than the signal, will be suppressed by an accurate measurement of the momentum of the K+ (with a silicon beam tracker named GigaTracker) and the π+ (with a straw tracker) and by a complex system of particle identification and veto detectors. A critical background can be induced by inelastic interactions of the hadron beam with the GigaTracker. Pions produced in these interactions, emitted at low angle, can reach the straw tracker and mimic a kaon decay in the fiducial region, if no other track is detected. In order to suppress this background a CHarged track ANTIcounter ...

  13. Complex Impedance of Fast Optical Transition Edge Sensors up to 30 MHz

    Science.gov (United States)

    Hattori, K.; Kobayashi, R.; Numata, T.; Inoue, S.; Fukuda, D.

    2018-03-01

    Optical transition edge sensors (TESs) are characterized by a very fast response, of the order of μs, which is 10^3 times faster than TESs for X-ray and gamma-ray. To extract important parameters associated with the optical TES, complex impedances at high frequencies (> 1 MHz) need to be measured, where the parasitic impedance in the circuit and reflections of electrical signals due to discontinuities in the characteristic impedance of the readout circuits become significant. This prevents the measurements of the current sensitivity β , which can be extracted from the complex impedance. In usual setups, it is hard to build a circuit model taking into account the parasitic impedances and reflections. In this study, we present an alternative method to estimate a transfer function without investigating the details of the entire circuit. Based on this method, the complex impedance up to 30 MHz was measured. The parameters were extracted from the impedance and were compared with other measurements. Using these parameters, we calculated the theoretical limit on an energy resolution and compared it with the measured energy resolution. In this paper, the reasons for the deviation of the measured value from theoretically predicted values will be discussed.

  14. Fast Hydrogen-Air Flames for Turbulence Driven Deflagration to Detonation Transition

    Science.gov (United States)

    Chambers, Jessica; Ahmed, Kareem

    2016-11-01

    Flame acceleration to Detonation produces several combustion modes as the Deflagration-to-Detonation Transition (DDT) is initiated, including fast deflagration, auto-ignition, and quasi-detonation. Shock flame interactions and turbulence levels in the reactant mixture drive rapid flame expansion, formation of a leading shockwave and post-shock conditions. An experimental study to characterize the developing shock and flame front behavior of propagating premixed hydrogen-air flames in a square channel is presented. To produce each flame regime, turbulence levels and flame propagation velocity are controlled using perforated plates in several configurations within the experimental facility. High speed optical diagnostics including Schlieren and Particle Image Velocimetry are used to capture the flow field. In-flow pressure measurements acquired post-shock, detail the dynamic changes that occur in the compressed gas directly ahead of the propagating flame. Emphasis on characterizing the turbulent post-shock environment of the various flame regimes helps identify the optimum conditions to initiate the DDT process. The study aims to further the understanding of complex physical mechanisms that drive transient flame conditions for detonation initiation. American Chemical Society.

  15. Hormonal changes associated with the transition between nursing and natural fasting in northern elephant seals (Mirounga angustirostris)

    Science.gov (United States)

    Ortiz, Rudy M.; Houser, Dorian S.; Wade, Charles E.; Ortiz, C. Leo

    2003-01-01

    To better interpret previously described hormonal changes observed during the natural postweaning fast (2-3 months) endured by pups of the northern elephant seal (Mirounga angustirostris), we compared plasma cortisol, thyroid hormones, and leptin in pups (n=5) measured during nursing and fasting periods. Blood samples were taken at four times; early (9 days postpartum) and late (18-22 days postpartum) nursing, and early (second week postweaning) and late (eighth week postweaning) fasting. Plasma cortisol increased 39% between early and late nursing and almost 4-fold by late fasting. After the early nursing period, cortisol and body mass were negatively correlated (y=28.3-0.19 x; R=0.569; p=0.027). Total thyroxine (tT(4)), free T(4) (fT(4)), total triiodothyronine (tT3) and reverse T(3) (rT(3)) were greatest at early nursing and reduced by late nursing and remained so throughout the fast, with the exception of tT(4), which increased between late nursing (17.7+/-2.1 ng mL(-1)) and late fasting (30.1+/-2.8 ng mL(-1)) periods. Leptin remained unaltered among the four sampling periods and was not correlated with body mass. Pups appear to exhibit a shift in the relationship between cortisol and body mass suggesting a potential role for cortisol in the regulation of body fat. The higher concentrations of tT(3) and tT(4) during early nursing may reflect enhanced growth and development during this period, however the increase late in fasting is likely physiologically insignificant and an artifact of reduced metabolic clearance of these hormones. Transition of the pups from nursing to fasting states is characterized by a striking lack of change in cortisol, thyroid hormones, and leptin suggesting that any metabolic alterations associated with this transition may occur independent of these hormones.

  16. Joint estimation of the fast and thermal components of a high neutron flux with a two on-line detector system

    International Nuclear Information System (INIS)

    Filliatre, P.; Oriol, L.; Jammes, C.; Vermeeren, L.

    2009-01-01

    A fission chamber with a 242 Pu deposit is the best suited detector for on-line measurements of the fast component of a high neutron flux (∼10 14 ncm -2 s -1 or more) with a significant thermal component. To get the fast flux, it is, however, necessary to subtract the contribution of the thermal neutrons, which increases with fluence because of the evolution of the isotopic content of the deposit. This paper presents an algorithm that permits, thanks to measurements provided by a 242 Pu fission chamber and a detector for thermal neutrons, to estimate the thermal and the fast flux at any time. An implementation allows to test it with simulated data.

  17. Joint estimation of the fast and thermal components of a high neutron flux with a two on-line detector system

    Energy Technology Data Exchange (ETDEWEB)

    Filliatre, P. [CEA, DEN, SPEx/LDCI, F-13108 Saint-Paul-lez-Durance (France); Laboratoire Commun d' Instrumentation CEA-SCK-CEN (France)], E-mail: philippe.filliatre@cea.fr; Oriol, L.; Jammes, C. [CEA, DEN, SPEx/LDCI, F-13108 Saint-Paul-lez-Durance (France); Laboratoire Commun d' Instrumentation CEA-SCK-CEN (France); Vermeeren, L. [SCK-CEN, Boeretang 200, B-2400 Mol (Belgium); Laboratoire Commun d' Instrumentation CEA-SCK-CEN (France)

    2009-05-21

    A fission chamber with a {sup 242}Pu deposit is the best suited detector for on-line measurements of the fast component of a high neutron flux ({approx}10{sup 14}ncm{sup -2}s{sup -1} or more) with a significant thermal component. To get the fast flux, it is, however, necessary to subtract the contribution of the thermal neutrons, which increases with fluence because of the evolution of the isotopic content of the deposit. This paper presents an algorithm that permits, thanks to measurements provided by a {sup 242}Pu fission chamber and a detector for thermal neutrons, to estimate the thermal and the fast flux at any time. An implementation allows to test it with simulated data.

  18. Fast parallel tracking algorithm for the muon detector of the CBM experiment at FAIR

    International Nuclear Information System (INIS)

    Lebedev, A.; Hoehne, C.; Kisel', I.; Ososkov, G.

    2010-01-01

    Particle trajectory recognition is an important and challenging task in the Compressed Baryonic Matter (CBM) experiment at the future FAIR accelerator at Darmstadt. The tracking algorithms have to process terabytes of input data produced in particle collisions. Therefore, the speed of the tracking software is extremely important for data analysis. In this contribution, a fast parallel track reconstruction algorithm, which uses available features of modern processors is presented. These features comprise a SIMD instruction set (SSE) and multithreading. The first allows one to pack several data items into one register and to operate on all of them in parallel thus achieving more operations per cycle. The second feature enables the routines to exploit all available CPU cores and hardware threads. This parallel version of the tracking algorithm has been compared to the initial serial scalar version which uses a similar approach for tracking. A speed-upfactor of 487 was achieved (from 730 to 1.5 ms/event) for a computer with 2 x Intel Core 17 processors at 2.66 GHz

  19. Fast Imaging Detector Readout Circuits with In-Pixel ADCs for Fourier Transform Imaging Spectrometers

    Science.gov (United States)

    Rider, D.; Blavier, J-F.; Cunningham, T.; Hancock, B.; Key, R.; Pannell, Z.; Sander, S.; Seshadri, S.; Sun, C.; Wrigley, C.

    2011-01-01

    Focal plane arrays (FPAs) with high frame rates and many pixels benefit several upcoming Earth science missions including GEO-CAPE, GACM, and ACE by enabling broader spatial coverage and higher spectral resolution. FPAs for the PanFTS, a high spatial resolution Fourier transform spectrometer and a candidate instrument for the GEO-CAPE mission are the focus of the developments reported here, but this FPA technology has the potential to enable a variety of future measurements and instruments. The ESTO ACT Program funded the developed of a fast readout integrated circuit (ROIC) based on an innovative in-pixel analog-to-digital converter (ADC). The 128 X 128 pixel ROIC features 60 ?m pixels, a 14-bit ADC in each pixel and operates at a continuous frame rate of 14 kHz consuming only 1.1 W of power. The ROIC outputs digitized data completely eliminating the bulky, power consuming signal chains needed by conventional FPAs. The 128 X 128 pixel ROIC has been fabricated in CMOS and tested at the Jet Propulsion Laboratory. The current version is designed to be hybridized with PIN photodiode arrays via indium bump bonding for light detection in the visible and ultraviolet spectral regions. However, the ROIC design incorporates a small photodiode in each cell to permit detailed characterization of the ROICperformance without the need for hybridization. We will describe the essential features of the ROIC design and present results of ROIC performance measurements.

  20. ATLAS strip detector: Operational Experience and Run1 → Run2 transition

    CERN Document Server

    NAGAI, K; The ATLAS collaboration

    2014-01-01

    The ATLAS SCT operational experience and the detector performance during the RUN1 period of LHC will be reported. Additionally the preparation outward to RUN2 during the long shut down 1 will be mentioned.

  1. Search for Pauli exclusion principle violating atomic transitions and electron decay with a p-type point contact germanium detector

    Energy Technology Data Exchange (ETDEWEB)

    Abgrall, N.; Bradley, A.W.; Chan, Y.D.; Mertens, S.; Poon, A.W.P. [Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Arnquist, I.J.; Hoppe, E.W.; Kouzes, R.T.; LaFerriere, B.D.; Orrell, J.L. [Pacific Northwest National Laboratory, Richland, WA (United States); Avignone, F.T. [Oak Ridge National Laboratory, Oak Ridge, TN (United States); University of South Carolina, Department of Physics and Astronomy, Columbia, SC (United States); Barabash, A.S.; Konovalov, S.I.; Yumatov, V. [National Research Center ' ' Kurchatov Institute' ' Institute for Theoretical and Experimental Physics, Moscow (Russian Federation); Bertrand, F.E.; Galindo-Uribarri, A.; Radford, D.C.; Varner, R.L.; White, B.R.; Yu, C.H. [Oak Ridge National Laboratory, Oak Ridge, TN (United States); Brudanin, V.; Shirchenko, M.; Vasilyev, S.; Yakushev, E.; Zhitnikov, I. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Busch, M. [Duke University, Department of Physics, Durham, NC (United States); Triangle Universities Nuclear Laboratory, Durham, NC (United States); Buuck, M.; Cuesta, C.; Detwiler, J.A.; Gruszko, J.; Guinn, I.S.; Leon, J.; Robertson, R.G.H. [University of Washington, Department of Physics, Center for Experimental Nuclear Physics and Astrophysics, Seattle, WA (United States); Caldwell, A.S.; Christofferson, C.D.; Dunagan, C.; Howard, S.; Suriano, A.M. [South Dakota School of Mines and Technology, Rapid City, SD (United States); Chu, P.H.; Elliott, S.R.; Goett, J.; Massarczyk, R.; Rielage, K. [Los Alamos National Laboratory, Los Alamos, NM (United States); Efremenko, Yu. [University of Tennessee, Department of Physics and Astronomy, Knoxville, TN (United States); Ejiri, H. [Osaka University, Research Center for Nuclear Physics, Ibaraki, Osaka (Japan); Finnerty, P.S.; Gilliss, T.; Giovanetti, G.K.; Henning, R.; Howe, M.A.; MacMullin, J.; Meijer, S.J.; O' Shaughnessy, C.; Rager, J.; Shanks, B.; Trimble, J.E.; Vorren, K.; Xu, W. [Triangle Universities Nuclear Laboratory, Durham, NC (United States); University of North Carolina, Department of Physics and Astronomy, Chapel Hill, NC (United States); Green, M.P. [North Carolina State University, Department of Physics, Raleigh, NC (United States); Oak Ridge National Laboratory, Oak Ridge, TN (United States); Triangle Universities Nuclear Laboratory, Durham, NC (United States); Guiseppe, V.E.; Tedeschi, D.; Wiseman, C. [University of South Carolina, Department of Physics and Astronomy, Columbia, SC (United States); Jasinski, B.R. [University of South Dakota, Department of Physics, Vermillion, SD (United States); Keeter, K.J. [Black Hills State University, Department of Physics, Spearfish, SD (United States); Kidd, M.F. [Tennessee Tech University, Cookeville, TN (United States); Martin, R.D. [Queen' s University, Department of Physics, Engineering Physics and Astronomy, Kingston, ON (Canada); Romero-Romero, E. [Oak Ridge National Laboratory, Oak Ridge, TN (United States); University of Tennessee, Department of Physics and Astronomy, Knoxville, TN (United States); Vetter, K. [Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA (United States); University of California, Department of Nuclear Engineering, Berkeley, CA (United States); Wilkerson, J.F. [Oak Ridge National Laboratory, Oak Ridge, TN (United States); Triangle Universities Nuclear Laboratory, Durham, NC (United States); University of North Carolina, Department of Physics and Astronomy, Chapel Hill, NC (United States)

    2016-11-15

    A search for Pauli-exclusion-principle-violating K{sub α} electron transitions was performed using 89.5 kg-d of data collected with a p-type point contact high-purity germanium detector operated at the Kimballton Underground Research Facility. A lower limit on the transition lifetime of 5.8 x 10{sup 30} s at 90% C.L. was set by looking for a peak at 10.6 keV resulting from the X-ray and Auger electrons present following the transition. A similar analysis was done to look for the decay of atomic K-shell electrons into neutrinos, resulting in a lower limit of 6.8 x 10{sup 30} s at 90% C.L. It is estimated that the Majorana Demonstrator, a 44 kg array of p-type point contact detectors that will search for the neutrinoless double-beta decay of {sup 76}Ge, could improve upon these exclusion limits by an order of magnitude after three years of operation. (orig.)

  2. Test beam studies of possibilities to separate particles with gamma factors above 103 with straw based Transition Radiation Detector

    Science.gov (United States)

    Belyaev, N.; Cherry, M. L.; Doronin, S. A.; Filippov, K.; Fusco, P.; Konovalov, S.; Krasnopevtsev, D.; Kramarenko, V.; Loparco, F.; Mazziotta, M. N.; Ponomarenko, D.; Pyatiizbyantseva, D.; Radomskii, R.; Rembser, C.; Romaniouk, A.; Savchenko, A.; Shulga, E.; Smirnov, S.; Smirnov, Yu; Sosnovtsev, V.; Spinelli, P.; Teterin, P.; Tikhomirov, V.; Vorobev, K.; Zhukov, K.

    2017-12-01

    Measurements of hadron production in the TeV energy range are one of the tasks of the future studies at the Large Hadron Collider (LHC). The main goal of these experiments is a study of the fundamental QCD processes at this energy range, which is very important not only for probing of the Standard Model but also for ultrahigh-energy cosmic particle physics. One of the key elements of these experiments measurements are hadron identification. The only detector technology which has a potential ability to separate hadrons in this energy range is Transition Radiation Detector (TRD) technology. TRD prototype based on straw proportional chambers combined with a specially assembled radiator has been tested at the CERN SPS accelerator beam. The test beam results and comparison with detailed Monte Carlo simulations are presented here.

  3. Heat capacity and transition behavior of sucrose by standard, fast scanning and temperature-modulated calorimetry

    Energy Technology Data Exchange (ETDEWEB)

    Magoń, A. [Department of Chemistry, University of Technology, 35-959 Rzeszów (Poland); Wurm, A.; Schick, C. [Department of Physics, University of Rostock, 18057 Rostock (Germany); Pangloli, Ph.; Zivanovic, S. [Department of Food Science and Technology, University of Tennessee, Knoxville, TN 37996 (United States); Skotnicki, M. [Department of Pharmaceutical Technology, Poznan University of Medical Sciences, 60-780 Poznań (Poland); Pyda, M., E-mail: mpyda@utk.edu [Department of Chemistry, University of Technology, 35-959 Rzeszów (Poland)

    2014-08-10

    Highlights: • Experimental, apparent heat capacity of sucrose was investigated by advanced thermal analysis. • Vibrational heat capacity of solid state was linked with a low temperature experimental heat capacity of sucrose. • Equilibrium melting parameters of sucrose were determined. • Decomposition, superheating of crystalline sucrose during melting process were presented. • TGA, DSC, TMDSC, and FSC are useful tools for characterization of sucrose. - Abstract: The heat capacity (C{sub p}) of crystalline and amorphous sucrose was determined using standard and quasi-isothermal temperature modulated differential scanning calorimetry. The results were combined with the published data determined by adiabatic calorimetry, and the C{sub p} values are now reported for the wide 5–600 K range. The experimental C{sub p} of solid sucrose at 5–300 K was used to calculate the vibrational, solid C{sub p} based on the vibrational molecular motions. The calculated solid and liquid C{sub p} together with the transition parameters for equilibrium conditions were used as references for detailed quantitative thermal analysis of crystalline and amorphous sucrose. Melting temperature (T{sub m}) of the crystalline sucrose was identified in a broad 442–465 K range with a heat of fusion of 40–46 J/mol determined at heating rates 0.5–20 K/min, respectively. The equilibrium T{sub m} and heat of fusion of crystalline sucrose were estimated at zero heating rate as T{sup o}{sub m} = 424.4 K and ΔH{sup o}{sub f} = 32 kJ/mol, respectively. The glass transition temperature (T{sub g}) of amorphous sucrose was at 331 K with a change in C{sub p} of 267 J/(mol K) as it was estimated from reversing heat capacity by quasi-isothermal TMDSC on cooling. At heating rates less than 30 K/min, thermal decomposition occurred during melting, while at extreme rate of 1000 K/s, degradation was not observed. Data obtained by fast scanning calorimetry (FSC) at 1000 K/s, showed that T{sub m} was

  4. Study on the novel neutron-to-proton convertor for improving the detection efficiency of a triple GEM based fast neutron detector

    International Nuclear Information System (INIS)

    Wang Xiaodong; Yang Lei; Zhang Chunhui; Hu Bitao; Yang Herun; Zhang Junwei; Ren Zhongguo; Ha Ri-Ba-La; An Luxing

    2015-01-01

    A high-efficiency fast neutron detector prototype based on a triple Gas Electron Multiplier (GEM) detector, which, coupled with a novel multi-layered high-density polyethylene (HDPE) as a neutron-to-proton converter for improving the neutron detection efficiency, is introduced and tested with the Am-Be neutron source in the Institute of Modern Physics (IMP) at Lanzhou in the present work. First, the developed triple GEM detector is tested by measuring its effective gain and energy resolution with "5"5Fe X-ray source to ensure that it has a good performance. The effective gain and obtained energy resolution is 5.0 × 10"4 and around 19.2%, respectively. Secondly, the novel multi-layered HDPE converter is coupled with the cathode of the triple GEM detector making it a high-efficiency fast neutron detector. Its effective neutron response is four times higher than that of the traditional single-layered conversion technique when the converter layer number is 38. (authors)

  5. Detection of nitro-based and peroxide-based explosives by fast polarity-switchable ion mobility spectrometer with ion focusing in vicinity of Faraday detector.

    Science.gov (United States)

    Zhou, Qinghua; Peng, Liying; Jiang, Dandan; Wang, Xin; Wang, Haiyan; Li, Haiyang

    2015-05-29

    Ion mobility spectrometer (IMS) has been widely deployed for on-site detection of explosives. The common nitro-based explosives are usually detected by negative IMS while the emerging peroxide-based explosives are better detected by positive IMS. In this study, a fast polarity-switchable IMS was constructed to detect these two explosive species in a single measurement. As the large traditional Faraday detector would cause a trailing reactant ion peak (RIP), a Faraday detector with ion focusing in vicinity was developed by reducing the detector radius to 3.3 mm and increasing the voltage difference between aperture grid and its front guard ring to 591 V, which could remove trailing peaks from RIP without loss of signal intensity. This fast polarity-switchable IMS with ion focusing in vicinity of Faraday detector was employed to detect a mixture of 10 ng 2,4,6-trinitrotoluene (TNT) and 50 ng hexamethylene triperoxide diamine (HMTD) by polarity-switching, and the result suggested that [TNT-H](-) and [HMTD+H](+) could be detected in a single measurement. Furthermore, the removal of trailing peaks from RIP by the Faraday detector with ion focusing in vicinity also promised the accurate identification of KClO4, KNO3 and S in common inorganic explosives, whose product ion peaks were fairly adjacent to RIP.

  6. Performance of the transition radiation detector flown on the NMSU/WIZARD TS93 balloon-borne instrument

    Energy Technology Data Exchange (ETDEWEB)

    Aversa, F.; Barbiellini, G.; Boezio, M. [Trieste Univ. (Italy). Dip. di Fisica]|[INFN, Trieste (Italy); Basini, G.; Brancaccio, F.M. [INFN, Laboratori nazionali di Frascati, Frascati, Rome (Italy); Bellotti, R. [Bari Univ. (Italy). Dip. di Fisica]|[INFN, Bari (Italy); Bidoli, V. [Rome Univ. `Tor Vergata` (Italy). Dip. di Fisica]|[INFN, Sezione Univ. `Tor Vergata` Rome (Italy); Bocciolini, M. [Florence Univ. (Italy). Dip. di Fisica]|[INFN, Florence (Italy); Bronzini, F. [Rome Univ. `La Sapienza` (Italy). Dip. di Fisica]|[INFN, Sezione Univ. `La Sapienza` Rome (Italy)

    1995-09-01

    It is built and tested a transition radiation detector (TRD) to discriminate positrons from protons in the balloon flight TS 93 experiment. It is presented the TRD performance using flight data obtaining a proton-positron rejection factor of the order of 10{sup -3}. During the 24 hour flight, the data in the momentum range 4-50 GeV/c are collected. Using the TRD together with the Silicon calorimeter, it is achieved an overall rejection factor of about 10{sup -5} of positron against the proton background over the entire momentum range.

  7. A novel transition radiation detector utilizing superconducting microspheres for measuring the energy of relativistic high-energy charged particles

    International Nuclear Information System (INIS)

    Yuan, Luke C.L.; Chen, C.P.; Huang, C.Y.; Lee, S.C.; Waysand, G.; Perrier, P.; Limagne, D.; Jeudy, V.; Girard, T.

    2000-01-01

    A novel transition radiation detector (TRD) utilizing superheated superconducting microspheres of tin of 22-26, 27-32 and 32-38 μm in diameter, respectively, has been constructed which is capable of measuring accurately the energy of relativistic high-energy charged particles. The test has been conducted in a high-energy electron beam facility at the CERN PS in the energy range of 1-10 GeV showing an energy dependence of the TR X-ray photon produced and hence the value γ=E/mc 2 of the charged particle

  8. First Tests of a New Fast Waveform Digitizer for PMT Signal Read-out from Liquid Argon Dark Matter Detectors

    Science.gov (United States)

    Szelc, A. M.; Canci, N.; Cavanna, F.; Cortopassi, A.; D'Incecco, M.; Mini, G.; Pietropaolo, F.; Romboli, A.; Segreto, E.; Acciarri, R.

    A new generation Waveform Digitizer board as been recently made available on the market by CAEN. The new board CAEN V1751 with 8 Channels per board, 10 bit, 1 GS/s Flash ADC Waveform Digitizer (or 4 channel, 10 bit, 2 GS/s Flash ADC Waveform Digitizer -Dual Edge Sampling mode) with threshold and Auto-Trigger capabilities provides an ideal (relatively low-cost) solution for reading signals from liquid Argon detectors for Dark Matter search equipped with an array of PMTs for the detection of scintillation light. The board was extensively used in real experimental conditions to test its usefulness for possible future uses and to compare it with a state of the art digital oscilloscope. As results, PMT Signal sampling at 1 or 2 GS/s is appropriate for the reconstruction of the fast component of the signal scintillation in Argon (characteristic time of about 4 ns) and the extended dynamic range, after a small customization, allows for the detection of signals in the range of energy needed. The bandwidth is found to be adequate and the intrinsic noise is very low.

  9. A High-Performance FPGA-Based Image Feature Detector and Matcher Based on the FAST and BRIEF Algorithms

    Directory of Open Access Journals (Sweden)

    Michał Fularz

    2015-10-01

    Full Text Available Image feature detection and matching is a fundamental operation in image processing. As the detected and matched features are used as input data for high-level computer vision algorithms, the matching accuracy directly influences the quality of the results of the whole computer vision system. Moreover, as the algorithms are frequently used as a part of a real-time processing pipeline, the speed at which the input image data are handled is also a concern. The paper proposes an embedded system architecture for feature detection and matching. The architecture implements the FAST feature detector and the BRIEF feature descriptor and is capable of establishing key point correspondences in the input image data stream coming from either an external sensor or memory at a speed of hundreds of frames per second, so that it can cope with most demanding applications. Moreover, the proposed design is highly flexible and configurable, and facilitates the trade-off between the processing speed and programmable logic resource utilization. All the designed hardware blocks are designed to use standard, widely adopted hardware interfaces based on the AMBA AXI4 interface protocol and are connected using an underlying direct memory access (DMA architecture, enabling bottleneck-free inter-component data transfers.

  10. Enhancement of sensitivity and bandwidth of gravitational wave detectors using fast-light-based white light cavities

    International Nuclear Information System (INIS)

    Salit, M; Shahriar, M S

    2010-01-01

    The effect of gravitational waves (GWs) has been observed indirectly, by monitoring the change in the orbital frequency of neutron stars in a binary system as they lose energy via gravitational radiation. However, GWs have not yet been observed directly. The initial LIGO apparatus has not yet observed GWs. The advanced LIGO (AdLIGO) will use a combination of improved techniques in order to increase the sensitivity. Along with power recycling and a higher power laser source, the AdLIGO will employ signal recycling (SR). While SR would increase sensitivity, it would also reduce the bandwidth significantly. Previously, we and others have investigated, theoretically and experimentally, the feasibility of using a fast-light-based white light cavity (WLC) to circumvent this constraint. However, in the previous work, it was not clear how one would incorporate the white light cavity effect. Here, we first develop a general model for Michelson-interferometer-based GW detectors that can be easily adapted to include the effects of incorporating a WLC into the design. We then describe a concrete design of a WLC constructed as a compound mirror, to replace the signal recycling mirror. This design is simple, robust, completely non-invasive, and can be added to the AdLIGO system without changing any other optical elements. We show a choice of parameters for which the signal sensitivity as well as the bandwidth are enhanced significantly over what is planned for the AdLIGO, covering the entire spectrum of interest for gravitational waves

  11. Usage of the micropixel detector TimePix for observation of the dynamics of phase transitions in metals

    Directory of Open Access Journals (Sweden)

    M. V. Pugach

    2012-12-01

    Full Text Available The results for the test of a TimePix hybrid detector as a tool for measuring and imaging in real time dynamics of phase transitions in metal alloys under heating or cooling are presented. The X-rays ( ~ 10 keV experimental setup explored for the diffraction studies at the Institute for Problems of Material Science NASU (Kyiv is briefly described. An evolution of the diffraction maxima position (~ 20 μm accuracy of the scattered X-rays was ob-served with exposures from a few dozen to a few hundred milliseconds under heating or cooling of the samples of Armco iron at a rate of 100 to 250 C/s. Data for the phase transitions (alpha-, gamma-phases observed during heating/cooling (20 - 1250 °C using the X-ray diffraction were measured.

  12. Optimization of a transition radiation detector for the compressed baryonic matter experiment

    Energy Technology Data Exchange (ETDEWEB)

    Arend, Andreas

    2014-07-01

    The Transition Radiation Detector (TRD) of the compressed baryonic matter (CBM) experiment at FAIR has to provide electron-pion separation as well as charged-particle tracking. Within this work, thin and symmetric Multi-Wire Proportional Chambers (MWPCs) without additional drift region were proposed. the proposed prototypes feature a foil-based entrance window to minimize the material budget and to reduce the absorption probability of the generated TR photon. Based on the conceptual design of thin and symmetric MWPCs without drift region, multiple prototypes were constructed and their performance presented within this thesis. With the constructed prototypes of generations II and III the geometries of the wire and cathode planes were determined to be 4+4 mm and 5+5 mm. Based on the results of a performed test beam campaign in 2011 with this prototypes new prototypes of generation IV were manufactured and tested in a subsequent test beam campaign in 2012. Prototypes of different radiators were developed together with the MWPC prototypes. Along with regular foil radiators, foam-based radiator types made of polyethylene foam were utilized. Also radiators constructed in a sandwich design, which used different fiber materials confined with solid foam sheets, were used. For the prototypes without drift region, simulations of the electrostatic and mechanical properties were performed. The GARFIELD software package was used to simulate the electric field and to determine the resulting drift lines of the generated electrons. The mean gas amplification depending on the utilized gas and the applied anode voltage was simulated and the gas-gain homogeneity was verified. Since the thin foil-based entrance window experiences a deformation due to pressure differences inside and outside the MWPC, the variation on the gas gain depending on the deformation was simulated. The mechanical properties focusing on the stability of the entrance window was determined with a finiteelement

  13. Optimization of a transition radiation detector for the compressed baryonic matter experiment

    International Nuclear Information System (INIS)

    Arend, Andreas

    2014-01-01

    The Transition Radiation Detector (TRD) of the compressed baryonic matter (CBM) experiment at FAIR has to provide electron-pion separation as well as charged-particle tracking. Within this work, thin and symmetric Multi-Wire Proportional Chambers (MWPCs) without additional drift region were proposed. the proposed prototypes feature a foil-based entrance window to minimize the material budget and to reduce the absorption probability of the generated TR photon. Based on the conceptual design of thin and symmetric MWPCs without drift region, multiple prototypes were constructed and their performance presented within this thesis. With the constructed prototypes of generations II and III the geometries of the wire and cathode planes were determined to be 4+4 mm and 5+5 mm. Based on the results of a performed test beam campaign in 2011 with this prototypes new prototypes of generation IV were manufactured and tested in a subsequent test beam campaign in 2012. Prototypes of different radiators were developed together with the MWPC prototypes. Along with regular foil radiators, foam-based radiator types made of polyethylene foam were utilized. Also radiators constructed in a sandwich design, which used different fiber materials confined with solid foam sheets, were used. For the prototypes without drift region, simulations of the electrostatic and mechanical properties were performed. The GARFIELD software package was used to simulate the electric field and to determine the resulting drift lines of the generated electrons. The mean gas amplification depending on the utilized gas and the applied anode voltage was simulated and the gas-gain homogeneity was verified. Since the thin foil-based entrance window experiences a deformation due to pressure differences inside and outside the MWPC, the variation on the gas gain depending on the deformation was simulated. The mechanical properties focusing on the stability of the entrance window was determined with a finiteelement

  14. Transition from hydrodynamic to fast sound in a He-Ne mixture a neutron Brillouin scattering experiment

    CERN Document Server

    Bafile, U; Barocchi, F; Sampoli, M

    2002-01-01

    The presence of a fast-sound mode in the microscopic dynamics of the rare-gas mixture He-Ne, predicted by theoretical studies and molecular-dynamics simulations, was demonstrated by an inelastic neutron scattering experiment. In order to study the transition between the fast and the normal acoustic modes in the hydrodynamic regime, k values lower by about one order of magnitude than in the usual experiments have to be probed. We describe here the results of the first neutron Brillouin scattering experiment performed with this purpose on the same system already investigated at larger k. The results of both experiments, together with those of a new molecular-dynamics simulation, provide a complete and consistent description, still missing so far, of the onset of fast-sound propagation in a binary mixture. (orig.)

  15. Scanning transient current study of the I-V stabilization phenomena in silicon detectors irradiated by fast neutrons

    International Nuclear Information System (INIS)

    Eremin, V.; Verbitskaya, E.; Sidorov, A.; Fretwurst, E.; Lindstrom, G.

    1996-03-01

    Investigation of the I-V stabilization phenomena in neutron irradiated silicon detectors has been carried out using scanning transient current technique (STCT) on non-irradiated PP + -p-n + detectors. The PP + -p-n + detectors were used to simulate the PP + -n-n + detectors irradiated beyond the space charge sign inversion (SCSI). Two mechanisms partially responsible for the I- V stabilization have been identified

  16. On the optimal choice of the laminar medium substance for ultrarelativistic particle transition radiation detectors

    International Nuclear Information System (INIS)

    Avakian, A.L.; Garibian, G.M.; Yang, C.

    1975-01-01

    The dependence of the X-ray transition yield in the energy region 10-20keV produced by an ultrarelativistic charged particle in various laminar media on the substance of the plates is investigated in detail. It is shown that in this case beryllium is the most optimal substance. Other energy regions of transition radiation quanta are also considered. (Auth.)

  17. High-voltage safety fuses for the transition-radiation tracking detector in the ATLAS experiment

    NARCIS (Netherlands)

    Voronov, SA; Voronov, YA; Onishchenko, EM; Simakov, AB; Sosnovtsev, VV; Suchkov, SI; Sugrobova, TA

    2004-01-01

    A safety fuse has been designed for the electrical protection of gas-filled detectors in the ATLAS experiment at CERN (Geneva, Switzerland). The fuse is a polished lithium niobate plate with a titanium strip of 91-kOmega resistance deposited by the photolithographic technique. The forced blow-out

  18. ATLAS inner detector: the Run 1 to Run 2 transition, and first experience from Run 2

    CERN Document Server

    Dobos, Daniel; The ATLAS collaboration

    2015-01-01

    The ATLAS experiment is equipped with a tracking system, the Inner Detector, built using different technologies, silicon planar sensors (pixel and micro-strip) and gaseous drift- tubes, all embedded in a 2T solenoidal magnetic field. For the LHC Run II, the system has been upgraded; taking advantage of the long showdown, the Pixel Detector was extracted from the experiment and brought to surface, to equip it with new service quarter panels, to repair modules and to ease installation of the Insertable B-Layer (IBL), a fourth layer of pixel detectors, installed in May 2014 between the existing Pixel Detector and a new smaller radius beam-pipe at a radius of 3.3 cm from the beam axis. To cope with the high radiation and pixel occupancy due to the proximity to the interaction point and the increase of Luminosity that LHC will face in Run-2, a new read-out chip within CMOS 130nm and two different silicon sensor pixel technologies (planar and 3D) have been developed. SCT and TRT systems consolidation was also carri...

  19. Commercialization of Micro-fabrication of Antenna-Coupled Transition Edge Sensor Bolometer Detectors for Studies of the Cosmic Microwave Background

    Science.gov (United States)

    Suzuki, Aritoki; Bebek, Chris; Garcia-Sciveres, Maurice; Holland, Stephen; Kusaka, Akito; Lee, Adrian T.; Palaio, Nicholas; Roe, Natalie; Steinmetz, Leo

    2018-04-01

    We report on the development of commercially fabricated multichroic antenna-coupled transition edge sensor (TES) bolometer arrays for cosmic microwave background (CMB) polarimetry experiments. CMB polarimetry experiments have deployed instruments in stages. Stage II experiments deployed with O(1000) detectors and reported successful detection of B-mode (divergence-free) polarization pattern in the CMB. Stage III experiments have recently started observing with O(10,000) detectors with wider frequency coverage. A concept for a stage IV experiment, CMB-S4, is emerging to make a definitive measurement of CMB polarization from the ground with O(400,000) detectors. The orders of magnitude increase in detector count for CMB-S4 require a new approach in detector fabrication to increase fabrication throughput and reduce the cost. We report on collaborative efforts with two commercial micro-fabrication foundries to fabricate antenna-coupled TES bolometer detectors. The detector design is based on the sinuous antenna-coupled dichroic detector from the POLARBEAR-2 experiment. The TES bolometers showed the expected I-V response, and the RF performance agrees with the simulation. We will discuss the motivation, design consideration, fabrication processes, test results, and how industrial detector fabrication could be a path to fabricate hundreds of detector wafers for future CMB polarimetry experiments.

  20. Precision measurement of sub-nanosecond lifetimes of excited nuclear states using fast-timing coincidences with LaBr3(Ce) detectors

    International Nuclear Information System (INIS)

    Regan, P.H.

    2015-01-01

    Precision measurements of electromagnetic (EM) transition rates enable tests of models of internal nuclear structure. Measurements of transition rates can be used to infer the spin and parity differences between the initial and final discrete nuclear excited states via which the EM transition takes place. This short conference paper reports on developments of detection systems for the identification of discrete energy gamma-ray decays using arrays of halide-scintillation detectors acting in coincidence mode, which can be used to determine electromagnetic transition rates between excited nuclear states in the sub-nanosecond temporal regime. Ongoing development of a new multi-detector LaBr 3 (Ce) array for studies of exotic nuclei produced at the upcoming Facility for Anti-Proton and Ion Research (FAIR) as part of the NUSTAR–DESPEC project are presented, together with initial results from pre-NUSTAR implementations of this array for nuclear structure studies of neutron-rich fission fragment radionuclides at ILL-Grenoble, France and RIBF at RIKEN, Japan. - Highlights: • This paper reports on new detection systems for identification of gamma decays. • It focusses on using arrays of halide-scintillation detectors in coincidence mode. • These can determine lifetimes of nuclear states at the sub-ns level. • Plans for new LaBr3(Ce) arrays for studies of exotic nuclei are presented.

  1. Fast reactor core design studies to cope with TRU fuel composition changes in the LWR-to-FBR transition period

    International Nuclear Information System (INIS)

    Kawashima, Katsuyuki; Maruyama, Shuhei; Ohki, Shigeo; Mizuno, Tomoyasu

    2009-01-01

    As part of the Fast Reactor Cycle Technology Development Project (FaCT Project), sodium-cooled fast reactor core design efforts have been made to cope with the TRU fuel composition changes expected during LWR-to-FBR transition period, in which a various kind of TRU fuel compositions are available depending on the characteristics of the LWR spent fuels and a way of recycling them. A 750 MWe mixed-oxide fuel core is firstly defined as a FaCT medium-size reference core and its neutronics characteristics are determined. The core is a high internal conversion type and has an average burnup of 150 GWD/T. The reference TRU fuel composition is assumed to come from the FBR equilibrium state. Compared to the LWR-to-FBR transition period, the TRU fuels in the FBR equilibrium period are multi-recycled through fast reactors and have a different composition. An available TRU fuel composition is determined by fast reactor spent fuel multi-recycling scenarios. Then the FaCT core corresponding to the TRU fuel with different compositions is set according to the TRU fuel composition changes in LWR-to-FBR transition period, and the key core neutronics characteristics are assessed. It is shown that among the core neutronics characteristics, the burnup reactivity and the safety parameters such as sodium void reactivity and Doppler coefficient are significantly influenced by the TRU fuel composition changes. As a result, a general characteristic in the FaCT core design to cope with TRU fuel composition changes is grasped and the design envelopes are identified in terms of the burnup reactivity and the safety parameters. (author)

  2. Measurements of atomic transition probabilities in highly ionized atoms by fast ion beams

    International Nuclear Information System (INIS)

    Martinson, I.; Curtis, L.J.; Lindgaerd, A.

    1977-01-01

    A summary is given of the beam-foil method by which level lifetimes and transition probabilities can be determined in atoms and ions. Results are presented for systems of particular interest for fusion research, such as the Li, Be, Na, Mg, Cu and Zn isoelectronic sequences. The available experimental material is compared to theoretical transition probabilities. (author)

  3. Preparation of bubble damage detectors

    International Nuclear Information System (INIS)

    Tu Caiqing; Guo Shilun; Wang Yulan; Hao Xiuhong; Chen Changmao; Su Jingling

    1997-01-01

    Bubble damage detectors have been prepared by using polyacrylamide as detector solid and freon as detector liquid. Tests show that the prepared detectors are sensitive to fast neutrons and have proportionality between bubble number and neutron fluence within a certain range of neutron fluence. Therefore, it can be used as a fast neutron detector and a dosimeter

  4. A Semi-Continuous State-Transition Probability HMM-Based Voice Activity Detector

    Directory of Open Access Journals (Sweden)

    H. Othman

    2007-02-01

    Full Text Available We introduce an efficient hidden Markov model-based voice activity detection (VAD algorithm with time-variant state-transition probabilities in the underlying Markov chain. The transition probabilities vary in an exponential charge/discharge scheme and are softly merged with state conditional likelihood into a final VAD decision. Working in the domain of ITU-T G.729 parameters, with no additional cost for feature extraction, the proposed algorithm significantly outperforms G.729 Annex B VAD while providing a balanced tradeoff between clipping and false detection errors. The performance compares very favorably with the adaptive multirate VAD, option 2 (AMR2.

  5. A Semi-Continuous State-Transition Probability HMM-Based Voice Activity Detector

    Directory of Open Access Journals (Sweden)

    Othman H

    2007-01-01

    Full Text Available We introduce an efficient hidden Markov model-based voice activity detection (VAD algorithm with time-variant state-transition probabilities in the underlying Markov chain. The transition probabilities vary in an exponential charge/discharge scheme and are softly merged with state conditional likelihood into a final VAD decision. Working in the domain of ITU-T G.729 parameters, with no additional cost for feature extraction, the proposed algorithm significantly outperforms G.729 Annex B VAD while providing a balanced tradeoff between clipping and false detection errors. The performance compares very favorably with the adaptive multirate VAD, option 2 (AMR2.

  6. Method of summation of amplitudes of coinciding pulses from Ge(Li) detectors used to study cascades of gamma-transitions in (n,#betta#) reaction

    International Nuclear Information System (INIS)

    Bogdzel', A.A.; Vasil'eva, Eh.V.; Elizarov, O.I.

    1982-01-01

    Main performanes and peculiarities of spectrometer based on the coincidence pulse amplitude total-count method and containing two Ge(La) detectors with transmission neutron spectrometer - IBR-30 pulse reactor are considered. It is shown on the 35 Cl(n, #betta#) reaction that the method of summalion of amplitudes of coinciding pulses from the Ge(Li) detector can be used to study the cascades of two #betta#-transitions with a total energy similar to the neutron binding energy. The shape of the response function of this spectrometer was studied versus the energies of #betta#-transition cascades

  7. Adipocyte Glucocorticoid Receptor Deficiency Attenuates Aging- and HFD-Induced Obesity and Impairs the Feeding-Fasting Transition.

    Science.gov (United States)

    Mueller, Kristina M; Hartmann, Kerstin; Kaltenecker, Doris; Vettorazzi, Sabine; Bauer, Mandy; Mauser, Lea; Amann, Sabine; Jall, Sigrid; Fischer, Katrin; Esterbauer, Harald; Müller, Timo D; Tschöp, Matthias H; Magnes, Christoph; Haybaeck, Johannes; Scherer, Thomas; Bordag, Natalie; Tuckermann, Jan P; Moriggl, Richard

    2017-02-01

    Glucocorticoids (GCs) are important regulators of systemic energy metabolism, and aberrant GC action is linked to metabolic dysfunctions. Yet, the extent to which normal and pathophysiological energy metabolism depend on the GC receptor (GR) in adipocytes remains unclear. Here, we demonstrate that adipocyte GR deficiency in mice significantly impacts systemic metabolism in different energetic states. Plasma metabolomics and biochemical analyses revealed a marked global effect of GR deficiency on systemic metabolite abundance and, thus, substrate partitioning in fed and fasted states. This correlated with a decreased lipolytic capacity of GR-deficient adipocytes under postabsorptive and fasting conditions, resulting from impaired signal transduction from β-adrenergic receptors to adenylate cyclase. Upon prolonged fasting, the impaired lipolytic response resulted in abnormal substrate utilization and lean mass wasting. Conversely, GR deficiency attenuated aging-/diet-associated obesity, adipocyte hypertrophy, and liver steatosis. Systemic glucose tolerance was improved in obese GR-deficient mice, which was associated with increased insulin signaling in muscle and adipose tissue. We conclude that the GR in adipocytes exerts central but diverging roles in the regulation of metabolic homeostasis depending on the energetic state. The adipocyte GR is indispensable for the feeding-fasting transition but also promotes adiposity and associated metabolic disorders in fat-fed and aged mice. © 2017 by the American Diabetes Association.

  8. Pantothenate kinase 1 is required to support the metabolic transition from the fed to the fasted state.

    Directory of Open Access Journals (Sweden)

    Roberta Leonardi

    2010-06-01

    Full Text Available Coenzyme A (CoA biosynthesis is regulated by the pantothenate kinases (PanK, of which there are four active isoforms. The PanK1 isoform is selectively expressed in liver and accounted for 40% of the total PanK activity in this organ. CoA synthesis was limited using a Pank1(-/- knockout mouse model to determine whether the regulation of CoA levels was critical to liver function. The elimination of PanK1 reduced hepatic CoA levels, and fasting triggered a substantial increase in total hepatic CoA in both Pank1(-/- and wild-type mice. The increase in hepatic CoA during fasting was blunted in the Pank1(-/- mouse, and resulted in reduced fatty acid oxidation as evidenced by abnormally high accumulation of long-chain acyl-CoAs, acyl-carnitines, and triglycerides in the form of lipid droplets. The Pank1(-/- mice became hypoglycemic during a fast due to impaired gluconeogenesis, although ketogenesis was normal. These data illustrate the importance of PanK1 and elevated liver CoA levels during fasting to support the metabolic transition from glucose utilization and fatty acid synthesis to gluconeogenesis and fatty acid oxidation. The findings also suggest that PanK1 may be a suitable target for therapeutic intervention in metabolic disorders that feature hyperglycemia and hypertriglyceridemia.

  9. Ultrafast secondary emission x-ray imaging detectors

    International Nuclear Information System (INIS)

    Akkerman, A.; Gibrekhterman, A.; Majewski, S.

    1991-07-01

    Fast high accuracy, x-ray imaging at high photon flux can be achieved when coupling thin solid convertors to gaseous electron multipliers, operating at low gas pressures. Secondary electron emitted from the convertor foil are multiplied in several successive amplification elements. The obvious advantage of solid x-ray detectors, as compared to gaseous conversion, are the production of parallax-free images and the fast (subnanoseconds) response. These x-ray detectors have many potential applications in basic and applied research. Of particular interest is the possibility of an efficient and ultrafast high resolution imaging of transition radiation,with a reduced dE/dx background. We present experimental results on the operation of the secondary emission x-ray (SEX) detectors, their detection efficiency, localization and time resolution. The experimental work is accompanied by mathematical modelling and computer simulation of transition radiation detectors based on CsI transition radiation convertors. (author)

  10. Large-area, low-noise, high-speed, photodiode-based fluorescence detectors with fast overdrive recovery

    International Nuclear Information System (INIS)

    Bickman, S.; DeMille, D.

    2005-01-01

    Two large-area, low-noise, high-speed fluorescence detectors have been built. One detector consists of a photodiode with an area of 28 mmx28 mm and a low-noise transimpedance amplifier. This detector has a input light-equivalent spectral noise density of less than 3 pW/√(Hz), can recover from a large scattered light pulse within 10 μs, and has a bandwidth of at least 900 kHz. The second detector consists of a 16-mm-diam avalanche photodiode and a low-noise transimpedance amplifier. This detector has an input light-equivalent spectral noise density of 0.08 pW/√(Hz), also can recover from a large scattered light pulse within 10 μs, and has a bandwidth of 1 MHz

  11. Evidence from n=2 fine structure transitions for the production of fast excited state positronium

    International Nuclear Information System (INIS)

    Ley, R.; Niebling, K.D.; Schwarz, R.; Werth, G.

    1990-01-01

    Fine structure transitions in the first excited state of positronium (Ps) have been measured using 'Backscatter Ps' production on a Mo surface by observation of a change in the emitted Lyman-α intensity under resonant microwave irradiation. Production, fine structure transitions and Lyman-α decay of the Ps atoms took place inside a waveguide designed to transmit the microwave frequencies of 8.6, 13.0 and 18.5 GHz for the transitions from the 2 3 S 1 state to the 2 3 P J , J=2, 1, 0, states, respectively. In the presence of a magnetic field, all transitions observed show a shift to higher frequencies, compared with earlier calculations and measurements in zero magnetic field. The deviations exceed the expected Zeeman shift significantly but may be explained by assuming a motional Stark effect for Ps with kinetic energies of several eV. (author)

  12. SiPM photosensors and fast timing readout for the Barrel Time-of-Flight detector in bar PANDA

    Science.gov (United States)

    Suzuki, K.

    2018-03-01

    The Barrel Time-of-Flight detector system will be installed in the upcoming bar PANDA experiment at FAIR in Germany. The detector has a barrel shape of phi=0.5 m and 1.8 m long, covering about 5 m2, which corresponds to the laboratory polar angle coverage of 22oPANDA Barrel Time-of-Flight detector are presented. The test shows that the current design fulfils satisfactorily the required timing performance (σt~ 56 ps) and the timing performance depends little on the hit position on the surface.

  13. High rate resistive plate chambers: An inexpensive, fast, large area detector of energetic charged particles for accelerator and non-accelerator applications

    International Nuclear Information System (INIS)

    Wuest, C.R.; Ables, E.; Bionta, R.M.; Clamp, O.; Haro, M.; Mauger, G.J.; Miller, K.; Olson, H.; Ramsey, P.

    1993-05-01

    Resistive Plate Chambers, or RPCs, have been used until recently as large detectors of cosmic ray muons. They are now finding use as fast large-area trigger and muon detection systems for different high energy physics detectors such the L3 Detector at LEP and future detectors to be built at the Superconducting Super Collider (SSC) and at the Large Hadron Collider (LHC) at CERN. RPC systems at these accelerators must operate with high efficiency, providing nanosecond timing resolution in particle fluences up to a few tens of kHz/cm 2 -- with thousands of square meters of active area. RPCs are simple and cheap to construct. The authors report here recent work on RPCs using new materials that exhibit a combination of desirable RPC features such as low bulk resistivity, high dielectric strength, low mass, and low cost. These new materials were originally developed for use in electronics assembly areas and other applications, where static electric charge buildup can damage sensitive electrical systems

  14. Sol-to-Gel Transition in Fast Evaporating Systems Observed by in Situ Time-Resolved Infrared Spectroscopy.

    Science.gov (United States)

    Innocenzi, Plinio; Malfatti, Luca; Carboni, Davide; Takahashi, Masahide

    2015-06-22

    The in situ observation of a sol-to-gel transition in fast evaporating systems is a challenging task and the lack of a suitable experimental design, which includes the chemistry and the analytical method, has limited the observations. We synthesise an acidic sol, employing only tetraethylorthosilicate, SiCl4 as catalyst and deuterated water; the absence of water added to the sol allows us to follow the absorption from the external environment and the evaporation of deuterated water. The time-resolved data, obtained by attenuated total reflection infrared spectroscopy on an evaporating droplet, enables us to identify four different stages during evaporation. They are linked to specific hydrolysis and condensation rates that affect the uptake of water from external environment. The second stage is characterized by a decrease in hydroxyl content, a fast rise of condensation rate and an almost stationary absorption of water. This stage has been associated with the sol-to-gel transition. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Discontinuity in Fast Dynamics at the Glass Transition of ortho-Terphenyl.

    Science.gov (United States)

    Hoffman, David J; Fayer, Michael D

    2017-11-16

    The dynamics of the molecular glass former ortho-terphenyl through the glass transition were observed with two-dimensional infrared vibrational spectroscopy measurements of spectral diffusion using the small probe molecule phenylselenocyanate. Although the slow diffusive motions were not visible on the experimental time scale, a picosecond-scale exponential relaxation was observed at temperatures from above to well below the glass transition temperature. The characteristic time scale has a smooth temperature dependence from the liquid into the glass phase, but the range of vibrational frequencies the probe samples displayed a discontinuity at the glass transition temperature. Complementary pump-probe experiments associate the observed motion with density fluctuations. The key features of the dynamics are reproduced with a simple corrugated well potential energy surface model. In addition, the temperature dependence of the homogeneous vibrational dephasing was found to have a T 2 functional form, where T is the absolute temperature.

  16. Connection between slow and fast dynamics of molecular liquids around the glass transition

    DEFF Research Database (Denmark)

    Niss, Kristine; Dalle-Ferrier, Cecile; Frick, Bernhard

    2010-01-01

    The mean-square displacement (MSD) was measured by neutron scattering at various temperatures and pressures for a number of molecular glass-forming liquids. The MSD is invariant along the glass-transition line at the pressure studied, thus establishing an “intrinsic” Lindemann criterion for any...

  17. On the fast estimation of transit times application to BWR simulated data

    International Nuclear Information System (INIS)

    Antonopoulos-Domis, M.; Marseguerra, M.; Padovani, E.

    1996-01-01

    Real time estimators of transit times are proposed. BWR noise is simulated including a global component due to rod vibration. The time obtained form the simulation is used to investigate the robustness and noise immunity of the estimators. It is found that, in presence of a coincident (global) signal, the cross-correlation function is the worst estimator. (authors)

  18. CARIOCA : A Fast Binary Front-End Implemented in 0.25Pm CMOS using a Novel Current-Mode Technique for the LHCb Muon Detector

    CERN Multimedia

    2000-01-01

    The CARIOCA front-end is an amplifier discriminator chip, using 0.25mm CMOS technology, developed with a very fast and low noise preamplifier. This prototype was designed to have input impedance below 10W. Measurements showed a peaking time of 14ns and noise of 450e- at zero input capacitance, with a noise slope of 37.4 e-/pF. The sensitivity of 8mV/fC remains almost unchanged up to a detector capacitance of 120pF.

  19. Characterization of plastic nuclear track detectors on solid state, CR-39 and LR-115 and its possibilities application on thermal and fast neutron dosimetry

    International Nuclear Information System (INIS)

    Vallejo Delgado, L.R.

    1989-01-01

    This work is an study about the use feasibility of plastic nuclear track detectors, LR 115, II-B (of Eastmann Kodak Co) and CR-39 (of American Acrylics and Plastics), for thermal and fast neutron dosimetry, respectively. The LR-115 with converter (n, alpha) was exposed to thermal neutrons with energy of 0,046 e V, proceeding from nuclear reactor RECH-1 of Nuclear Energy Chilean Commission. The irradiated films were submited to a chemical etching with NaOH, plus a washing and brushing. The CR-39 with polyethylene irradiator, was exposed to fast neutrons proceeding of calibrated sources of Am-Se. The irradiated plates were submited to a chemical pre-etching with KOH and a electrochemical post-etching. (author)

  20. SiC-based neutron detector in quasi-realistic working conditions: efficiency and stability at room and high temperature under fast neutron irradiations

    Energy Technology Data Exchange (ETDEWEB)

    Ferone, Raffaello; Issa, Fatima; Ottaviani, Laurent; Biondo, Stephane; Vervisch, Vanessa [IM2NP, UMR CNRS 7334, Aix-Marseille University, Case 231,13397 Marseille Cedex 20, (France); Szalkai, Dora; Klix, Axel [KIT- Karlsruhe Institute of Technology, Institute of Neutron Physics and Reactor Technology Karlsruhe 76344, (Germany); Vermeeren, Ludo [SCK-CEN, Boeretang 200, B-2400 Mol, (Belgium); Saenger, Richard [Schlumberger, Clamart, (France); Lyoussi, Abadallah [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 the framework of the European I SMART project, we have designed and made new SiC-based nuclear radiation detectors able to operate in harsh environments and to detect both fast and thermal neutrons. In this paper, we report experimental results of fast neutron irradiation campaign at high temperature (106 deg. C) in quasi-realistic working conditions. Our device does not suffer from high temperature, and spectra do show strong stability, preserving features. These experiments, as well as others in progress, show the I SMART SiC-based device skills to operate in harsh environments, whereas other materials would strongly suffer from degradation. Work is still demanded to test our device at higher temperatures and to enhance efficiency in order to make our device fully exploitable from an industrial point of view. (authors)

  1. Phonon-mediated superconducting transition-edge sensor X-ray detectors for use in astronomy

    Science.gov (United States)

    Leman, Steven W.; Martinez-Galarce, Dennis S.; Brink, Paul L.; Cabrera, Blas; Castle, Joseph P.; Morse, Kathleen; Stern, Robert A.; Tomada, Astrid

    2004-09-01

    Superconducting Transition-Edge Sensors (TESs) are generating a great deal of interest in the areas of x-ray astrophysics and space science, particularly to develop them as large-array, imaging x-ray spectrometers. We are developing a novel concept that is based on position-sensitive macro-pixels placing TESs on the backside of a silicon or germanium absorber. Each x-ray absorbed will be position (X/δX and Y/δY ~ 100) and energy (E/δE ~ 1000) resolved via four distributed TES readouts. In the future, combining such macropixels with advances in multiplexing could lead to 30 by 30 arrays of close-packed macro-pixels equivalent to imaging instruments of 10 megapixels or more. We report on our progress to date and discuss its application to a plausible solar satellite mission and plans for future development.

  2. On the Unsteadiness of a Transitional Shock Wave-Boundary Layer Interaction Using Fast-Response Pressure-Sensitive Paint

    Science.gov (United States)

    Lash, E. Lara; Schmisseur, John

    2017-11-01

    Pressure-sensitive paint has been used to evaluate the unsteady dynamics of transitional and turbulent shock wave-boundary layer interactions generated by a vertical cylinder on a flat plate in a Mach 2 freestream. The resulting shock structure consists of an inviscid bow shock that bifurcates into a separation shock and trailing shock. The primary features of interest are the separation shock and an upstream influence shock that is intermittently present in transitional boundary layer interactions, but not observed in turbulent interactions. The power spectral densities, frequency peaks, and normalized wall pressures are analyzed as the incoming boundary layer state changes from transitional to fully turbulent, comparing both centerline and outboard regions of the interaction. The present study compares the scales and frequencies of the dynamics of the separation shock structure in different boundary layer regimes. Synchronized high-speed Schlieren imaging provides quantitative statistical analyses as well as qualitative comparisons to the fast-response pressure sensitive paint measurements. Materials based on research supported by the U.S. Office of Naval Research under Award Number N00014-15-1-2269.

  3. Health transitions, fast and nasty: the case of Marshallese exposure to nuclear radiation.

    Science.gov (United States)

    Pollock, Nancy J

    2002-09-01

    The concept of health transitions assumes that health status improves with the introduction of western medicine. In this paper I demonstrate that the health of the people of Rongelap, Marshall Islands, has undergone serious damage as a result of nuclear testing, and that women in particular have suffered unduly. Exposure to nuclear radiation over a period of almost fifty years has been recognised by US authorities as a major contributory cause to the high rates of cancers and birth defects suffered by the Rongelap people. Women's reproduction has been severely affected, as evidenced by the many stillbirths and small stature of children born alive. Two generations have been exposed to both background radiation and to radiation ingested with the local foods on which they rely in the absence of other food sources. Clean up has commenced only after this and other communities sought compensation from the United States. The Rongelap people will live with the effects of radiation for generations to come. This transition to ongoing health problems is thus a negative outcome of modern health transition.

  4. Subcritical-to-supercritical transition in quasi-perpendicular fast shocks

    International Nuclear Information System (INIS)

    Livesey, W.A.

    1985-01-01

    The magnetic structure of collisionless quasi-perpendicular bow shock waves was observed and studied using fluxgate magnetometer data from the ISEE-1 and 2 spacecraft. The angle theta/sub Bn/ between upstream magnetic field and the shock normal was determined for each case. The fast Mach number M, β/sub i/, and β/sub e/ of the shock waves were estimated using solar wind plasma parameters. The critical fast Mach number M/sub c/, the Mach number for which the downstream flow speed just equals the downstream sound speed, was calculated for each shock using the Rankine-Hugoniot shock jump conditions. A survey of the dependence of various magnetic substructures upon these parameters was performed. A precursor foot to the shock was noted for shock waves characterized by M/M/sub c/ > 1. The thickness of this foot region was in good quantitative agreement with predicted trajectories of solar wind ions undergoing specular reflection from the shock ramp

  5. Development of a scintillating-fibre detector for fast topological triggers in high-luminosity particle physics experiments

    CERN Document Server

    Agoritsas, V; Bing, O; Bravar, A; Cardini, A; Dreossi, D; Drevenak, R; Finger, M H; Flaminio, Vincenzo; Di Girolamo, B; Gorin, A; Kulikov, A; Kuroda, K; Manuilov, I V; Okada, K; Önel, Y M; Penzo, Aldo L; Rapin, D; Rappazzo, G F; Riazantsev, A V; Rykalin, V I; Slunecka, M; Takeutchi, F; Trusov, S V; Yoshida, T

    1998-01-01

    In the framework of the RD-17 project at CERN extensive work is in progresson the development of scintillating-fibre detectors using position-sensitive photomultipliers. With o.5 mm diameter fibres as spatial resolution of about 125 µm was obtained with a detection efficiency higher than 95%. The time resolution of the detector is about 600 ps, and the track position is properly digitized in real time in less than 10 ns by a peak sensing circuit. A simulation, based on experimental data, was also performed to compare different types of front-end electronics.

  6. A fast one-chip event-preprocessor and sequencer for the Simbol-X Low Energy Detector

    Science.gov (United States)

    Schanz, T.; Tenzer, C.; Maier, D.; Kendziorra, E.; Santangelo, A.

    2010-12-01

    We present an FPGA-based digital camera electronics consisting of an Event-Preprocessor (EPP) for on-board data preprocessing and a related Sequencer (SEQ) to generate the necessary signals to control the readout of the detector. The device has been originally designed for the Simbol-X low energy detector (LED). The EPP operates on 64×64 pixel images and has a real-time processing capability of more than 8000 frames per second. The already working releases of the EPP and the SEQ are now combined into one Digital-Camera-Controller-Chip (D3C).

  7. A fast one-chip event-preprocessor and sequencer for the Simbol-X Low Energy Detector

    Energy Technology Data Exchange (ETDEWEB)

    Schanz, T., E-mail: schanz@astro.uni-tuebingen.d [Kepler Center for Astro- and Particlephysics, Institut fuer Astronomie und Astrophysik Tuebingen, Sand 1, 72076 Tuebingen (Germany); Tenzer, C., E-mail: tenzer@astro.uni-tuebingen.d [Kepler Center for Astro- and Particlephysics, Institut fuer Astronomie und Astrophysik Tuebingen, Sand 1, 72076 Tuebingen (Germany); Maier, D.; Kendziorra, E.; Santangelo, A. [Kepler Center for Astro- and Particlephysics, Institut fuer Astronomie und Astrophysik Tuebingen, Sand 1, 72076 Tuebingen (Germany)

    2010-12-11

    We present an FPGA-based digital camera electronics consisting of an Event-Preprocessor (EPP) for on-board data preprocessing and a related Sequencer (SEQ) to generate the necessary signals to control the readout of the detector. The device has been originally designed for the Simbol-X low energy detector (LED). The EPP operates on 64x64 pixel images and has a real-time processing capability of more than 8000 frames per second. The already working releases of the EPP and the SEQ are now combined into one Digital-Camera-Controller-Chip (D3C).

  8. A fast one-chip event-preprocessor and sequencer for the Simbol-X Low Energy Detector

    International Nuclear Information System (INIS)

    Schanz, T.; Tenzer, C.; Maier, D.; Kendziorra, E.; Santangelo, A.

    2010-01-01

    We present an FPGA-based digital camera electronics consisting of an Event-Preprocessor (EPP) for on-board data preprocessing and a related Sequencer (SEQ) to generate the necessary signals to control the readout of the detector. The device has been originally designed for the Simbol-X low energy detector (LED). The EPP operates on 64x64 pixel images and has a real-time processing capability of more than 8000 frames per second. The already working releases of the EPP and the SEQ are now combined into one Digital-Camera-Controller-Chip (D3C).

  9. High transition temperature superconductor/insulator bilayers for the development of ultra-fast electronics

    International Nuclear Information System (INIS)

    Sirena, M.; Félix, L. Avilés; Haberkorn, N.

    2013-01-01

    High transition temperature superconductor (HTc)/SrTiO 3 (STO) bilayers were fabricated by sputtering deposition on (100) STO substrates. Their transport and morphological properties were characterized using conductive atomic force microscopy. The STO barriers present good insulating properties, with long attenuation lengths (λ ∼ 1 nm) which reduce the junction resistance and increase the operating critical current. The samples present roughness values smaller than 1 nm, with an extremely low density of surface defects (∼5 × 10 −5 defects/μm 2 ). The high control of the barrier quality over large defect free surfaces is encouraging for the development of microelectronics devices based in HTc Josephson junctions

  10. Impedance measurements on a fast transition-edge sensor for optical and near-infrared range

    International Nuclear Information System (INIS)

    Taralli, E; Portesi, C; Lolli, L; Monticone, E; Rajteri, M; Novikov, I; Beyer, J

    2010-01-01

    Impedance measurements of superconducting transition-edge sensors (TESs) are a powerful tool to obtain information about the TES thermal and electrical properties. We apply this technique to a 20 μm x 20 μm Ti/Au TES, suitable for application in the optical and near-infrared range, and extend the measurements up to 250 kHz in order to obtain a complete frequency response in the complex plane. From these measurements we obtain important thermal and electrical device parameters such as heat capacity C, thermal conductance G and effective thermal time constant τ eff that will be compared with the corresponding values obtained from noise measurements.

  11. Studies of the dependence on oxidation thermal processes of effects on the electrical properties of silicon detectors by fast neutron radiation

    International Nuclear Information System (INIS)

    Li, Zheng; Kraner, H.W.

    1991-11-01

    High resistivity silicon detectors along with MOS capacitors made on five silicon dioxides with different thermal conditions (975 degree C to 1200 degree C) have been exposed to fast neutron irradiation up to the fluence of a few times 10 14 n/cm 2 . New measurement techniques such as capacitance-voltage (C-V) of MOS capacitors and current-voltage (I-V) of back to back diodes (p + -n - - p + if n - is not inverted to p) or resistors (p + -p-p + if inverted) have been introduced in this study in monitoring the possible type-inversion (n→p) under high neutron fluence. No type-inversion in the material underneath SiO 2 and the p + contact has been observed so far in this work for detectors made on the five oxides up to the neutron fluence of a few times 10 13 n/cm 2 . However, it has been found that detectors made on higher temperature oxides (T≤ 1100 degree C) exhibit less leakage current increase at high neutron fluence (φ ≤ 10 13 n/cm 2 )

  12. Fast synchrotron and FEL beam monitors based on single-crystal diamond detectors and InGaAs/InAlAs quantum well devices

    Science.gov (United States)

    Antonelli, M.; Di Fraia, M.; Carrato, S.; Cautero, G.; Menk, R. H.; Jark, W. H.; Ganbold, T.; Biasiol, G.; Callegari, C.; Coreno, M.; De Sio, A.; Pace, E.

    2013-12-01

    Simultaneous photon-beam position and intensity monitoring is becoming of increasing importance for new-generation synchrotron radiation sources and free-electron lasers (FEL). Thus, novel concepts of beam diagnostics are required in order to keep such beams under control. From this perspective diamond is a promising material for the production of semitransparent in situ photon beam monitors, which can withstand the high dose rates occurring in such radiation facilities. Here, we report on the development of freestanding, single-crystal chemical-vapor-deposited diamond detectors with segmented electrodes. Due to their direct, low-energy band gap, InGaAs quantum well devices operated at room temperature may also be used as fast detectors for photons ranging from visible to X-ray. These features are valuable in low-energy and time-resolved FEL applications. In particular, a novel segmented InGaAs/InAlAs device has been developed and will be discussed. Dedicated measurements carried out on both these devices at the Elettra Synchrotron show their capability to monitor the position and the intensity of the photon beam with bunch-by-bunch temporal performances. Furthermore, preliminary tests have been performed on diamond detectors at the Fermi FEL, extracting quantitative intensity and position information for 100-fs-wide FEL pulses with a photon energy of 28.8 eV.

  13. Fast and high-energy neutron detection with nuclear track detectors: Results of the European joint experiments 1992/93

    Energy Technology Data Exchange (ETDEWEB)

    Schraube, H. [GSF - Forschungszentrum fuer Umwelt und Gesundheit Neuherberg GmbH, Oberschleissheim (Germany); Alberts, W.G. [Physikalisch-Technische Bundesanstalt, Braunschweig (Germany); Weeks, A.R. [comps.] [Nuclear Electric plc, Berkeley (United Kingdom). Berkeley Technology Centre

    1997-12-31

    Under the auspices of EURADOS, the European radiation dosimetry group, seventeen recognised laboratories engaged in the field of individual neutron dosimetry with passive track detectors participated in an international comparative experiment. A number of twenty-seven detector systems, predominantly etched track detectors with the material PADC (poly allyl diglycol carbonate), were employed by the participating laboratories. Quasi-monoenergetic neutrons were provided for irradiations free-in-air and on front of a PMMA phantom by the GSF (Forschungszentrum fuer Umwelt und Gesundheit, Neuherberg, Germany) and by the PTB (Physikalisch-Technische Bundesanstalt, Braunschweig, Germany). High energy irradiations were conducted by the PSI (Paul-Scherrer Institut, Villigen, Switzerland). The results of the on-phantom irradiations were used to derive energy and angular responses of the track detectors, those of the free-in-air irradiations to obtain data for the linearity characteristics of the response with dose. The report contains a short description and the original data of the participating laboratories, displays the irradiation and reference conditions, and provides an over-all evaluation. Emphasis is placed on the quantitative evaluation of the background characteristics and of the non-linearity observed with most of the systems employed which limits their useful dose-range of application. (orig.)

  14. Fast broad-band photon detector based on quantum well devices and charge-integrating electronics for non-invasive FEL monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Antonelli, M., E-mail: matias.antonelli@elettra.eu; Cautero, G.; Sergo, R.; Castellaro, C.; Menk, R. H. [Elettra – Sincrotrone Trieste S.C.p.A., Trieste (Italy); Ganbold, T. [School in Nanotechnology, University of Trieste, Trieste (Italy); IOM CNR, Laboratorio TASC, Trieste (Italy); Biasiol, G. [IOM CNR, Laboratorio TASC, Trieste (Italy)

    2016-07-27

    The recent evolution of free-electron lasers has not been matched by the development of adequate beam-monitoring instrumentation. However, for both experimental and diagnostics purposes, it is crucial to keep such photon beams under control, avoiding at the same time the absorption of the beam and the possible destruction of the detector. These requirements can be fulfilled by utilizing fast and non-invasive photon detectors operated in situ, upstream from the experimental station. From this perspective, sensors based on Quantum Well (QW) devices can be the key to detecting ultra-short light pulses. In fact, owing to their high electron mobility, InGaAs/InAlAs QW devices operated at room temperature exhibit sub-nanosecond response times. Their direct, low-energy band gap renders them capable of detecting photons ranging from visible to X-ray. Furthermore, the 2D electron gas forming inside the QW is responsible for a charge amplification mechanism, which increases the charge collection efficiency of these devices. In order to acquire the signals produced by these QW sensors, a novel readout electronics has been developed. It is based on a high-speed charge integrator, which allows short, low-intensity current pulses to be read within a 50-ns window. The integrated signal is acquired through an ADC and the entire process can be performed at a 10-MHz repetition rate. This work provides a detailed description of the development of the QW detectors and the acquisition electronics, as well as reporting the main experimental results, which show how these tools are well suited for the realization of fast, broad-band beam monitors.

  15. Applications of solid-state nuclear track detectors (SSNTDs) for fast ion and fusion reaction product measurements in TEXTOR experiments

    Energy Technology Data Exchange (ETDEWEB)

    Szydlowski, A.; Malinowski, K.; Malinowska, A. [Association EURTOM-IPPLM Warsaw, The Andrzej Soltan Institute for Nuclear Studies, 05-400 Otwock-Swierk (Poland); Wassenhove, G. Van [EURATOM-Belgium State Association, LPP, ERM/KMS, Trilateral Euregio Cluster, B-1000 Brussels (Belgium); Schweer, B. [Association EURATOM-FZJ, Institutte of Plasma Physicx, Juelich (Germany)

    2011-07-01

    Full text of publication follows: The paper reports on measurements of fusion reaction protons which were performed on TEXTOR facility in January 2009. The basic experimental scheme was similar to that applied in the previous measurements [1, 2]. The main experimental tool equipment was a small ion pinhole camera which was equipped with a PM-355 detector sample and was attached to a water cooled manipulator. The camera was placed below the plasma ring in the direction of ion drifts, at a distance of 4.4 cm from LCFS. However, in the described experiment it was aligned at an angle to the mayor TEXTOR radius (contrary to previous experiments), so that the input pinhole was oriented first at {gamma} = 45 degrees (shots 108799 - 108818) and then {gamma} = 600 (shots 108832 - 108847). The discharges were executed with one neutral beam of the total power 0.6 - 1.0 MW. In the first series (Nos 108799 - 108818) the plasma was additionally heated by ICRH of frequency 38 MHz. The irradiated detector samples were subjected to the same interrupted etching procedure as the samples used in the CR-39/PM-355 detector calibration measurements [1, 2]. After that, track density distributions and track diameter histograms were measured under an optical microscope. By the use of the calibration curves, it was possible to distinguish craters produced by protons from other craters and to convert the obtained histograms into proton energy spectra. The craters induced by lower energy ions appeared to be concentrated in narrower areas, whereas higher energy ions were registered in a more diffused detector fields. The paper shows again that the CR-39/PM-355 detector is an useful diagnostic tool for tokamak experiments, for measurement of charged ions. References: [1] A. Szydlowski, A. Malinowska, M. Jaskola, A. Korman, M.J. Sadowski, G. Van Wassenhove, B. Schweer and the TEXTOR team, A. Galkowski, 'Application of Solid State Nuclear Track Detectors in TEXTOR Experiment for Measurements

  16. Fast parallel algorithms that compute transitive closure of a fuzzy relation

    Science.gov (United States)

    Kreinovich, Vladik YA.

    1993-01-01

    The notion of a transitive closure of a fuzzy relation is very useful for clustering in pattern recognition, for fuzzy databases, etc. The original algorithm proposed by L. Zadeh (1971) requires the computation time O(n(sup 4)), where n is the number of elements in the relation. In 1974, J. C. Dunn proposed a O(n(sup 2)) algorithm. Since we must compute n(n-1)/2 different values s(a, b) (a not equal to b) that represent the fuzzy relation, and we need at least one computational step to compute each of these values, we cannot compute all of them in less than O(n(sup 2)) steps. So, Dunn's algorithm is in this sense optimal. For small n, it is ok. However, for big n (e.g., for big databases), it is still a lot, so it would be desirable to decrease the computation time (this problem was formulated by J. Bezdek). Since this decrease cannot be done on a sequential computer, the only way to do it is to use a computer with several processors working in parallel. We show that on a parallel computer, transitive closure can be computed in time O((log(sub 2)(n))2).

  17. Development of a signal-analysis algorithm for the ZEUS transition-radiation detector under application of a neural network

    International Nuclear Information System (INIS)

    Wollschlaeger, U.

    1992-07-01

    The aim of this thesis consisted in the development of a procedure for the analysis of the data of the transition-radiation detector at ZEUS. For this a neural network was applied and first studied, which results concerning the separation power between electron an pions can be reached by this procedure. It was shown that neural nets yield within the error limits as well results as standard algorithms (total charge, cluster analysis). At an electron efficiency of 90% pion contaminations in the range 1%-2% were reached. Furthermore it could be confirmed that neural networks can be considered for the here present application field as robust in relatively insensitive against external perturbations. For the application in the experiment beside the separation power also the time-behaviour is of importance. The requirement to keep dead-times small didn't allow the application of standard method. By a simulation the time availabel for the signal analysis was estimated. For the testing of the processing time in a neural network subsequently the corresponding algorithm was implemented into an assembler code for the digital signal processor DSP56001. (orig./HSI) [de

  18. Development of a fast pixel array detector for use in microsecond time-resolved x-ray diffraction

    International Nuclear Information System (INIS)

    Barna, S.L.; Gruner, S.M.; Shepherd, J.A.

    1995-01-01

    A large-area pixel x-ray detector is being developed to collect eight successive frames of wide dynamic range two-dimensional images at 200kHz rates. Such a detector, in conjunction with a synchrotron radiation x-ray source, will enable time-resolved x-ray studies of proteins and other materials on time scales which have previously been inaccessible. The detector will consist of an array of fully-depleted 150 micron square diodes connected to a CMOS integrated electronics layer with solder bump-bonding. During each framing period, the current resulting from the x-rays stopped in the diodes is integrated in the electronics layer, and then stored in one of eight storage capacitors underneath the pixel. After the last frame, the capacitors are read out at standard data transmission rates. The detector has been designed for a well-depth of at least 10,000 x-rays (at 20keV), and a noise level of one x-ray. Ultimately, the authors intend to construct a detector with over one million pixels (1024 by 1024). They present the results of their development effort and various features of the design. The electronics design is discussed, with special attention to the performance requirements. The choice and design of the detective diodes, as they relate to x-ray stopping power and charge collection, are presented. An analysis of various methods of bump bonding is also presented. Finally, the authors discuss the possible need for a radiation-blocking layer, to be placed between the electronics and the detective layer, and various methods they have pursued in the construction of such a layer

  19. Phase transition and fast agreement in the Naming Game with preference for multi-word agents

    International Nuclear Information System (INIS)

    Lipowska, Dorota; Lipowski, Adam

    2014-01-01

    We examine a variant of the Naming Game, where agents with several words communicate more often than single-word agents. Depending on the preference and dimensionality, the model either converges to a single-language state as in an ordinary Naming Game or remains in a disordered, multi-language phase. At the transition point separating these regimes, due to a percolation-like process, the model converges to a single-language state but much faster than in the ordinary naming game. We also show that the coarsening dynamics of the ordinary Naming Game is slower than expected due to stripe structures that sometimes spontaneously form during the evolution of the model. (paper)

  20. High transition temperature superconductor/insulator bilayers for the development of ultra-fast electronics

    Energy Technology Data Exchange (ETDEWEB)

    Sirena, M.; Félix, L. Avilés [Consejo Nacional de Investigaciones Científicas y Técnicas, Centro Atómico Bariloche, CNEA, Bustillo 9500, 8400 Bariloche (Argentina); Instituto Balseiro, Universidad Nacional de Cuyo and CNEA, 8400 Bariloche (Argentina); Haberkorn, N. [Consejo Nacional de Investigaciones Científicas y Técnicas, Centro Atómico Bariloche, CNEA, Bustillo 9500, 8400 Bariloche (Argentina)

    2013-07-29

    High transition temperature superconductor (HTc)/SrTiO{sub 3} (STO) bilayers were fabricated by sputtering deposition on (100) STO substrates. Their transport and morphological properties were characterized using conductive atomic force microscopy. The STO barriers present good insulating properties, with long attenuation lengths (λ ∼ 1 nm) which reduce the junction resistance and increase the operating critical current. The samples present roughness values smaller than 1 nm, with an extremely low density of surface defects (∼5 × 10{sup −5} defects/μm{sup 2}). The high control of the barrier quality over large defect free surfaces is encouraging for the development of microelectronics devices based in HTc Josephson junctions.

  1. Response of CR-39 Detector Against Fast Neutron Using D-Polyethylene and H-Polyethylene Radiator

    International Nuclear Information System (INIS)

    Sofyan, Hasnel

    1996-01-01

    The research on the response of detector CR-39 by using D-Polyethylene and H-Polyethylene radiator has been carried out. The optimum number of nuclear tracks was found with the use of 30 % NaOH at 80 + 0,5oC for 80 minutes of etching time. The comparison of CR-39 detector response caused by D-Polyethylene radiator against H-Polyethylene radiator of irradiation in air, were found to be 1.18 and 0.84 for 241Am-Be neutron source and neutron source from reactor respectively. For phantom irradiation, the results were found to be 1.75 for 241Am-Be neutron source, and 0.77 for neutron source from reactor

  2. Downshifting in the Fast Lane: A Post-Keynesian Model of a Consumer-Led Transition

    Directory of Open Access Journals (Sweden)

    Eric Kemp-Benedict

    2018-01-01

    Full Text Available If the world’s countries seriously tackle the climate targets agreed upon in Paris, their citizens are likely to experience substantial changes in production, consumption, and employment. We present a long-run post-Keynesian model for studying the potential implications of a major transition on macroeconomic stability and employment. It is a demand-led model in which firms have considerable but not absolute freedom to administer prices, while household consumption exhibits inertia. Firms continually seek input-saving technological improvements that, in aggregate, tie technological progress to firms’ cost structures. Together with firm pricing strategies and wage setting, the productivities of different inputs determine the functional income distribution. Saving and investment, and production and purchase of consumption goods, are undertaken by different economic actors, driven by income and capacity utilization, with the possibility that productive capacity exceeds, or falls short of, effective demand. The model produces business cycles and long waves driven by technological change. We present results for a “downshifting” scenario in which households voluntarily withdraw labor, and discuss the implications of downshifting for stability, growth, and employment. We contrast the downshifting scenario with ones in which households reduce consumption without withdrawing from the labor pool.

  3. Application of Semiempirical Methods to Transition Metal Complexes: Fast Results but Hard-to-Predict Accuracy.

    KAUST Repository

    Minenkov, Yury

    2018-05-22

    A series of semiempirical PM6* and PM7 methods has been tested in reproducing of relative conformational energies of 27 realistic-size complexes of 16 different transition metals (TMs). An analysis of relative energies derived from single-point energy evaluations on density functional theory (DFT) optimized conformers revealed pronounced deviations between semiempirical and DFT methods indicating fundamental difference in potential energy surfaces (PES). To identify the origin of the deviation, we compared fully optimized PM7 and respective DFT conformers. For many complexes, differences in PM7 and DFT conformational energies have been confirmed often manifesting themselves in false coordination of some atoms (H, O) to TMs and chemical transformations/distortion of coordination center geometry in PM7 structures. Despite geometry optimization with fixed coordination center geometry leads to some improvements in conformational energies, the resulting accuracy is still too low to recommend explored semiempirical methods for out-of-the-box conformational search/sampling: careful testing is always needed.

  4. Measurement of the spectral shift of the 3d→4p transitions in Ar+, Cl+ and S+ by means of collinear fast-beam laser spectroscopy

    International Nuclear Information System (INIS)

    Eichhorn, A.

    1981-01-01

    The spectral shift of the 3d→4p transitions in Ar + ( 36 Ar + and 40 Ar + ) Cl + ( 35 Cl + and 37 Cl + ) and S + ( 32 S + + 34 S + ) were measured by means of collinear fast-beam laser spectroscopy. Since the volume effect is neglectible only the normal and specific mass effect give contributions to the spectral shift. (BEF)

  5. Development of a silicon microstrip detector with single photon sensitivity for fast dynamic diffraction experiments at a synchrotron radiation beam

    Science.gov (United States)

    Arakcheev, A.; Aulchenko, V.; Kudashkin, D.; Shekhtman, L.; Tolochko, B.; Zhulanov, V.

    2017-06-01

    Time-resolved experiments on the diffraction of synchrotron radiation (SR) from crystalline materials provide information on the evolution of a material structure after a heat, electron beam or plasma interaction with a sample under study. Changes in the material structure happen within a microsecond scale and a detector with corresponding parameters is needed. The SR channel 8 of the VEPP-4M storage ring provides radiation from the 7-pole wiggler that allows to reach several tens photons within one μs from a tungsten crystal for the most intensive diffraction peak. In order to perform experiments that allow to measure the evolution of tungsten crystalline structure under the impact of powerful laser beam, a new detector is developed, that can provide information about the distribution of a scattered SR flux in space and its evolution in time at a microsecond scale. The detector is based on the silicon p-in-n microstrip sensor with DC-coupled metal strips. The sensor contains 1024 30 mm long strips with a 50 μm pitch. 64 strips are bonded to the front-end electronics based on APC128 ASICs. The APC128 ASIC contains 128 channels that consist of a low noise integrator with 32 analogue memory cells each. The integrator equivalent noise charge is about 2000 electrons and thus the signal from individual photons with energy above 40 keV can be observed. The signal can be stored at the analogue memory with 10 MHz rate. The first measurements with the beam scattered from a tungsten crystal with energy near 60 keV demonstrated the capability of this prototype to observe the spatial distribution of the photon flux with the intensity from below one photon per channel up to 0~10 photons per channel with a frame rate from 10 kHz up to 1 MHz.

  6. Experimental study of photon fast detector with a cathodic lecture in check pattern for annular focusing Cherenkov counters

    International Nuclear Information System (INIS)

    Arnold, R.; Guyonnet, J.L.; Giomataris, Y.; Seguinot, J.; Ypsilantis, T.

    1990-01-01

    It's about the experimental study of a photodetector for Cherenkov counters, able to separate events of a high multiplicity belonging to two successive collisions of beams (Interaction rate - 100 MHz for a luminosity of 10 33 cm -2 sec -1 at SSC). The detailed tests of the photodetector have been made to know its answer. (detection efficiency, rapidity, geometric resolution, reconstruction), to optimalize its geometry but also to elaborate and to test a Monte Carlo simulation program which can predict the comportment and the reconstruction resolution of a detector for several granularities of lecture for different devices of photon-electron converters or operation gases [fr

  7. Total OH reactivity measurements using a new fast Gas Chromatographic Photo-Ionization Detector (GC-PID

    Directory of Open Access Journals (Sweden)

    V. Sinha

    2012-12-01

    Full Text Available The primary and most important oxidant in the atmosphere is the hydroxyl radical (OH. Currently OH sinks, particularly gas phase reactions, are poorly constrained. One way to characterize the overall sink of OH is to measure directly the ambient loss rate of OH, the total OH reactivity. To date, direct measurements of total OH reactivity have been either performed using a Laser-Induced Fluorescence (LIF system ("pump-and-probe" or "flow reactor" or the Comparative Reactivity Method (CRM with a Proton-Transfer-Reaction Mass Spectrometer (PTR-MS. Both techniques require large, complex and expensive detection systems. This study presents a feasibility assessment for CRM total OH reactivity measurements using a new detector, a Gas Chromatographic Photoionization Detector (GC-PID. Such a system is smaller, more portable, less power consuming and less expensive than other total OH reactivity measurement techniques.

    Total OH reactivity is measured by the CRM using a competitive reaction between a reagent (here pyrrole with OH alone and in the presence of atmospheric reactive molecules. The new CRM method for total OH reactivity has been tested with parallel measurements of the GC-PID and the previously validated PTR-MS as detector for the reagent pyrrole during laboratory experiments, plant chamber and boreal field studies. Excellent agreement of both detectors was found when the GC-PID was operated under optimum conditions. Time resolution (60–70 s, sensitivity (LOD 3–6 s−1 and overall uncertainty (25% in optimum conditions for total OH reactivity were similar to PTR-MS based total OH reactivity measurements. One drawback of the GC-PID system was the steady loss of sensitivity and accuracy during intensive measurements lasting several weeks, and a possible toluene interference. Generally, the GC-PID system has been shown to produce closely comparable results to the PTR-MS and thus in suitable environments (e.g. forests it

  8. NINO, an ultra-fast, low-power, front-end amplifier discriminator for the Time-Of-Flight detector in ALICE experiment

    CERN Document Server

    Anghinolfi, F; Krummenacher, F; Usenko, E; Williams, M C S

    2004-01-01

    An ultra fast front-end preamplifier-discriminator chip NINO has been developed for use in the ALICE Time-Of-Flight detector. The chip has 8 channels. Each channel is designed with an amplifier with less than 1 ns peaking time, a discriminator with a minimum detection threshold of 10fC and an output stage. The output pulse has minimum time jitter (less than 25ps) on the front edge, and the pulse width is dependent of the input signal charge. Each channel consumes 27mW, and the 8 channels fit in a 2*4mm/sup 2/ ASIC processed in IBM 0.2 mu m CMOS technology. (3 refs).

  9. The use of fast and thermal neutron detectors based on oxide scintillators in inspection systems for prevention of illegal transportation of radioactive substances

    International Nuclear Information System (INIS)

    Ryzhikov, V. D.; Grinyov, B. V.; Piven, L. A.; Pochet, T.; Onyshchenko, G. M.; Lysetska, O. K.; Nagornaya, L. L.

    2009-01-01

    We present results of our studies aimed at practical application of an efficient method for detection of fast and thermal neutrons, which uses the process of inelastic scattering on atom nuclei present in inorganic scintillators. Due to energy transformation in inelastic scattering, the main fraction of gamma-radiation energy falls into the low-energy range (below 0.3 MeV). Detection in this range ensures efficiency that reaches up to 70% (as compared with 1% using conventional LiI(E)-techniques) and depends on the effective atomic number of the scintillator. The most evident practical application field for this method is inspection systems for prevention of illegal transportation of radioactive substances. Especially promising is the creation of a small-sized neutron detector for portable radioactive materials detection systems using the 'scintillator-avalanche photodiode' technology

  10. The Gigatracker: An ultra-fast and low-mass silicon pixel detector for the NA62 experiment

    International Nuclear Information System (INIS)

    Fiorini, M.; Carassiti, V.; Ceccucci, A.; Cortina, E.; Cotta Ramusino, A.; Dellacasa, G.; Garbolino, S.; Jarron, P.; Kaplon, J.; Kluge, A.; Mapelli, A.; Marchetto, F.; Martin, E.; Martoiu, S.; Mazza, G.; Morel, M.; Noy, M.; Nuessle, G.; Petrucci, F.; Riedler, P.

    2011-01-01

    The Gigatracker is a hybrid silicon pixel detector developed to track the highly intense NA62 hadron beam with a time resolution of 150 ps (rms). The beam spectrometer of the experiment is composed of three Gigatracker stations installed in vacuum in order to precisely measure momentum, time and direction of every traversing particle. Precise tracking demands a very low mass of the detector assembly ( 0 per station) in order to limit multiple scattering and beam hadronic interactions. The high rate and especially the high timing precision requirements are very demanding: two R and D options are ongoing and the corresponding prototype read-out chips have been recently designed and produced in 0.13μm CMOS technology. One solution makes use of a constant fraction discriminator and on-pixel analogue-based time-to-digital-converter (TDC); the other comprises a delay-locked loop based TDC placed at the end of each pixel column and a time-over-threshold discriminator with time-walk correction technique. The current status of the R and D program is overviewed and results from the prototype read-out chips test are presented.

  11. The Gigatracker: An ultra-fast and low-mass silicon pixel detector for the NA62 experiment

    Science.gov (United States)

    Fiorini, M.; Carassiti, V.; Ceccucci, A.; Cortina, E.; Cotta Ramusino, A.; Dellacasa, G.; Garbolino, S.; Jarron, P.; Kaplon, J.; Kluge, A.; Mapelli, A.; Marchetto, F.; Martin, E.; Martoiu, S.; Mazza, G.; Morel, M.; Noy, M.; Nuessle, G.; Petrucci, F.; Riedler, P.; Aglieri Rinella, G.; Rivetti, A.; Tiuraniemi, S.

    2011-02-01

    The Gigatracker is a hybrid silicon pixel detector developed to track the highly intense NA62 hadron beam with a time resolution of 150 ps (rms). The beam spectrometer of the experiment is composed of three Gigatracker stations installed in vacuum in order to precisely measure momentum, time and direction of every traversing particle. Precise tracking demands a very low mass of the detector assembly ( beam hadronic interactions. The high rate and especially the high timing precision requirements are very demanding: two R&D options are ongoing and the corresponding prototype read-out chips have been recently designed and produced in 0.13 μm CMOS technology. One solution makes use of a constant fraction discriminator and on-pixel analogue-based time-to-digital-converter (TDC); the other comprises a delay-locked loop based TDC placed at the end of each pixel column and a time-over-threshold discriminator with time-walk correction technique. The current status of the R&D program is overviewed and results from the prototype read-out chips test are presented.

  12. The Gigatracker: An ultra-fast and low-mass silicon pixel detector for the NA62 experiment

    CERN Document Server

    Fiorini, M; Morel, M; Petrucci, F; Marchetto, F; Garbolino, S; Cortina, E; Tiuraniemi, S; Ceccucci, A; Martin, E; Riedler, P; Martoiu, S; Ramusino, A C; Rinella, G A; Mapelli, A; Mazza, G; Noy, M; Jarron, P; Nuessle, G; Dellacasa, G; Kluge, A; Rivetti, A; Kaplon, J

    2011-01-01

    The Gigatracker is a hybrid silicon pixel detector developed to track the highly intense NA62 hadron beam with a time resolution of 150 ps (rms). The beam spectrometer of the experiment is composed of three Gigatracker stations installed in vacuum in order to precisely measure momentum, time and direction of every traversing particle. Precise tracking demands a very low mass of the detector assembly (<0.5\\% X(O) per station) in order to limit multiple scattering and beam hadronic interactions. The high rate and especially the high timing precision requirements are very demanding: two R\\&D options are ongoing and the corresponding prototype read-out chips have been recently designed and produced in 0.13 mu m CMOS technology. One solution makes use of a constant fraction discriminator and on-pixel analogue-based time-to-digital-converter (TDC); the other comprises a delay-locked loop based TDC placed at the end of each pixel column and a time-over-threshold discriminator with time-walk correction techniq...

  13. AM06: the Associative Memory chip for the Fast TracKer in the upgraded ATLAS detector

    International Nuclear Information System (INIS)

    Annovi, A.; Beretta, M. M.; Calderini, G.; Crescioli, F.; Frontini, L.; Liberali, V.; Shojaii, S.R.; Stabile, A.

    2017-01-01

    This paper describes the AM06 chip, which is a highly parallel processor for pattern recognition in the ATLAS high energy physics experiment. The AM06 contains memory banks that store data organized in 18 bit words; a group of 8 words is called 'pattern'. Each AM06 chip can store up to 131 072 patterns. The AM06 is a large chip, designed in 65 nm CMOS, and it combines full-custom memory arrays, standard logic cells and serializer/deserializer IP blocks at 2 Gbit/s for input/output communication. The overall silicon area is 168 mm 2 and the chip contains about 421 million transistors. The AM06 receives the detector data for each event accepted by Level-1 trigger, up to 100 kHz, and it performs a track reconstruction based on hit information from channels of the ATLAS silicon detectors. Thanks to the design of a new associative memory cell and to the layout optimization, the AM06 consumption is only about 1 fJ/bit per comparison. The AM06 has been fabricated and successfully tested with a dedicated test system.

  14. Fast Detector/First Responder: Interactions between the Superior Colliculus-Pulvinar Pathway and Stimuli Relevant to Primates

    Science.gov (United States)

    Soares, Sandra C.; Maior, Rafael S.; Isbell, Lynne A.; Tomaz, Carlos; Nishijo, Hisao

    2017-01-01

    Primates are distinguished from other mammals by their heavy reliance on the visual sense, which occurred as a result of natural selection continually favoring those individuals whose visual systems were more responsive to challenges in the natural world. Here we describe two independent but also interrelated visual systems, one cortical and the other subcortical, both of which have been modified and expanded in primates for different functions. Available evidence suggests that while the cortical visual system mainly functions to give primates the ability to assess and adjust to fluid social and ecological environments, the subcortical visual system appears to function as a rapid detector and first responder when time is of the essence, i.e., when survival requires very quick action. We focus here on the subcortical visual system with a review of behavioral and neurophysiological evidence that demonstrates its sensitivity to particular, often emotionally charged, ecological and social stimuli, i.e., snakes and fearful and aggressive facial expressions in conspecifics. We also review the literature on subcortical involvement during another, less emotional, situation that requires rapid detection and response—visually guided reaching and grasping during locomotion—to further emphasize our argument that the subcortical visual system evolved as a rapid detector/first responder, a function that remains in place today. Finally, we argue that investigating deficits in this subcortical system may provide greater understanding of Parkinson's disease and Autism Spectrum disorders (ASD). PMID:28261046

  15. Excitation of hybridized Dirac plasmon polaritons and transition radiation in multi-layer graphene traversed by a fast charged particle

    Science.gov (United States)

    Akbari, Kamran; Mišković, Zoran L.; Segui, Silvina; Gervasoni, Juana L.; Arista, Néstor R.

    2018-06-01

    We analyze the energy loss channels for a fast charged particle traversing a multi-layer graphene (MLG) structure with N layers under normal incidence. Focusing on a terahertz (THz) range of frequencies, and assuming equally doped graphene layers with a large enough separation d between them to neglect interlayer electron hopping, we use the Drude model for two-dimensional conductivity of each layer to describe hybridization of graphene’s Dirac plasmon polaritons (DPPs). Performing a layer decomposition of ohmic energy losses, which include excitation of hybridized DPPs (HDPPs), we have found for N = 3 that the middle HDPP eigenfrequency is not excited in the middle layer due to symmetry constraint, whereas the excitation of the lowest HDPP eigenfrequency produces a Fano resonance in the graphene layer that is first traversed by the charged particle. While the angular distribution of transition radiation emitted in the far field region also shows asymmetry with respect to the traversal order by the incident charged particle at supra-THz frequencies, the integrated radiative energy loss is surprisingly independent of both d and N for N ≤ 5, which is explained by a dominant role of the outer graphene layers in transition radiation. We have further found that the integrated ohmic energy loss in optically thin MLG scales as ∝1/N at sub-THz frequencies, which is explained by exposing the role of dissipative processes in graphene at low frequencies. Finally, prominent peaks are observed at supra-THz frequencies in the integrated ohmic energy loss for MLG structures that are not optically thin. The magnitude of those peaks is found to scale with N for N ≥ 2, while their shape and position replicate the peak in a double-layer graphene (N = 2), which is explained by arguing that plasmon hybridization in such MLG structures is dominated by electromagnetic interaction between the nearest-neighbor graphene layers.

  16. Measurement of fast neutron spectrum using CR-39 detectors and a new image analysis program (autoTRAKn)

    International Nuclear Information System (INIS)

    Paul, Sabyasachi; Tripathy, S.P.; Sahoo, G.S.; Bandyopadhyay, T.; Sarkar, P.K.

    2013-01-01

    An attempt is made to estimate the neutron spectrum using the CR-39 (Solid state nuclear track) detector and a new image analyzing program. For this purpose the earlier developed program (autoTRAK) is modified by introducing the required features such as angular correction for the recoil particles, fluence-to-dose conversion coefficient, detection sensitivity of CR-39 detectors, etc. to make it applicable for neutron spectrometry and dosimetry. This upgraded program (autoTRAK n ) is tested with a mono-energetic source (D–T) and two other standard neutron sources, viz. 241 Am–Be and 252 Cf. The program is validated by reproducing these standard spectra, and comparing with the spectra reported by other investigators using different measuring techniques. The ratios of dose equivalent (H ⁎ (10)) to fluence (Φ) are also estimated from the spectra and are compared with the reference values for these neutron sources. An additional feature of this program is explored for counting high density overlapping tracks more precisely and effectively compared to other commonly used image analyzing softwares. This method is found to be simple and promising, which can always be used as a supplementary measuring technique. The details of the modified program, reproduction and comparison of the neutron spectra, reproducibility of the methodology and example of overlapping track counting are presented and discussed. -- Highlights: •A novel image analysis technique (autoTRAK n ) is developed to evaluate CR-39 detectors used for neutron spectrometry and dosimetry. •The methodology is tested to reproduce three standard neutron spectra, (a) D–T, (b) 241 Am–Be, and (c) 252 Cf. •A good matching is observed between dosimetric values obtained by the program and the available reference values. •The program autoTRAK n is also observed to be efficient to distinguish high density overlapping tracks without any segregation procedure. •The methodology seems to be simple, which

  17. A method for unique identification of relativistic /greater than 0.5/ magnetic monopoles with a fast film Cerenkov detector

    Science.gov (United States)

    Pinsky, L. S.; Hagstrom, R.

    1975-01-01

    A magnetic monopole traversing a dielectric medium at a velocity greater than the phase velocity of light in that medium, will give rise to Cerenkov radiation with the electric field tangent to the cone generated by the photon wave propagation vector, and the magnetic field normal to that surface. This is the opposite polarization to that encountered with an electric charge. It is proposed that either by inserting a linearly polarizing layer between the radiator and the photographic emulsion, or by selecting a linearly polarizing material as the radiator, one could directly observe the field polarization by examining the photographic image and thus uniquely identify a magnetic monopole. The ability of the detector is further enhanced by the index of refraction dependence of the Cerenkov output from a magnetic monopole.

  18. Non-Linear Optical Phenomena in Detecting Materials as a Possibility for Fast Timing in Detectors of Ionizing Radiation

    CERN Document Server

    Korjik, M. V.; Buganov, O.; Fedorov, A. A.; Emelianchik, I.; Griesmayer, E.; Mechinsky, V.; Nargelas, S.; Sidletskiy, O.; Tamulaitis, G.; Tikhomirov, S. N.; Vaitkevicius, A.

    2016-01-01

    The time resolution of the detectors currently in use is limited by 50-70 ps due to the spontaneous processes involved in the development of the response signal, which forms after the relaxation of carriers generated during the interaction. In this study, we investigate the feasibility of exploiting sub-picosecond phenomena occurring after the interaction of scintillator material with ionizing radiation by probing the material with ultra-short laser pulses. One of the phenomena is the elastic polarization due to the local lattice distortion caused by the displacement of electrons and holes generated by ionization. The key feature of the elastic polarization is its short response time, which makes it prospective for using as an optically detectable time mark. The nonlinear optical absorption of femtosecond light pulses of appropriate wavelength is demonstrated to be a prospective tool to form the mark. This study was aimed at searching for inorganic crystalline media combining scintillation properties and non-...

  19. Test beam measurement of the first prototype of the fast silicon pixel monolithic detector for the TT-PET project

    Science.gov (United States)

    Paolozzi, L.; Bandi, Y.; Benoit, M.; Cardarelli, R.; Débieux, S.; Forshaw, D.; Hayakawa, D.; Iacobucci, G.; Kaynak, M.; Miucci, A.; Nessi, M.; Ratib, O.; Ripiccini, E.; Rücker, H.; Valerio, P.; Weber, M.

    2018-04-01

    The TT-PET collaboration is developing a PET scanner for small animals with 30 ps time-of-flight resolution and sub-millimetre 3D detection granularity. The sensitive element of the scanner is a monolithic silicon pixel detector based on state-of-the-art SiGe BiCMOS technology. The first ASIC prototype for the TT-PET was produced and tested in the laboratory and with minimum ionizing particles. The electronics exhibit an equivalent noise charge below 600 e‑ RMS and a pulse rise time of less than 2 ns , in accordance with the simulations. The pixels with a capacitance of 0.8 pF were measured to have a detection efficiency greater than 99% and, although in the absence of the post-processing, a time resolution of approximately 200 ps .

  20. Circumbinary, not transitional: on the spiral arms, cavity, shadows, fast radial flows, streamers, and horseshoe in the HD 142527 disc

    Science.gov (United States)

    Price, Daniel J.; Cuello, Nicolás; Pinte, Christophe; Mentiplay, Daniel; Casassus, Simon; Christiaens, Valentin; Kennedy, Grant M.; Cuadra, Jorge; Sebastian Perez, M.; Marino, Sebastian; Armitage, Philip J.; Zurlo, Alice; Juhasz, Attila; Ragusa, Enrico; Laibe, Guillaume; Lodato, Giuseppe

    2018-06-01

    We present 3D hydrodynamical models of the HD 142527 protoplanetary disc, a bright and well-studied disc that shows spirals and shadows in scattered light around a 100 au gas cavity, a large horseshoe dust structure in mm continuum emission, together with mysterious fast radial flows and streamers seen in gas kinematics. By considering several possible orbits consistent with the observed arc, we show that all of the main observational features can be explained by one mechanism - the interaction between the disc and the observed binary companion. We find that the spirals, shadows, and horseshoe are only produced in the correct position angles by a companion on an inclined and eccentric orbit approaching periastron - the `red' family from Lacour et al. Dust-gas simulations show radial and azimuthal concentration of dust around the cavity, consistent with the observed horseshoe. The success of this model in the HD 142527 disc suggests other mm-bright transition discs showing cavities, spirals, and dust asymmetries may also be explained by the interaction with central companions.

  1. An energy and direction independent fast neutron dosemeter based on electrochemically etched CR-39 nuclear track detectors

    International Nuclear Information System (INIS)

    James, K.; Matiullah; Durrani, S.A.

    1987-01-01

    A computer-based model is presented, which simulates the dose equivalent response of electrochemically etched CR-39 to fast neutrons of various energies and angles of incidence. Most previous calculations of the response of CR-39 have neglected the production of recoiling oxygen and carbon nuclei as well as α particles in the CR-39. We calculate that these 'heavy recoils' and α particles are the major source of electrochemically etchable tracks in bare CR-39 at neutron energies above approx. 2 MeV under typical etching conditions. Our calculations have been extended to predict the response of CR-39 used in conjunction with various combinations of polymeric front radiators and we have determined the radiator stack configuration with produces the most energy independent response. Again, the heavy recoils and α particles cannot be neglected and, for energies above approx. 2 MeV, these produce typically about 20% of the total response of our optimum stack. This type of fast neutron dosemeter is, however, strongly direction dependent. We have integrated the response over all appropriate angles to predict the dose equivalent response for two representative neutron fields, and we suggest a method for minimising the angular dependence. (author)

  2. Design of a trigger layout and the corresponding implementation of a 200 GB/s readout network for the ALICE transition radiation detector

    International Nuclear Information System (INIS)

    Schneider, Rolf

    2008-01-01

    Through the use of modern information technology, intelligent trigger systems are gaining more and more importance in high-energy physics. Particularly in heavy ion experiments, the large number of generated particles results in an enormous amount of data. By filtering the data at an early stage and discarding irrelevant events, the efficiency of the entire system can be raised significantly. The ALICE experiment at CERN breaks new ground in this respect. With the Transition Radiation Detector, the acquired signals are processed parallel right on the detector using more than 65 000 multi-chip modules. Via a readout network, the preprocessed data arrives at a global track reconstruction unit, which contributes to the decision whether an event is discarded or further processed. In this thesis, a trigger concept for the Transition Radiation Detector is developed and the readout network is implemented. A special challenge is to achieve an efficient interaction of the above processing stages. By means of simulations and analyses, the entire system is optimized in this regard. It turns out that the read-out process plays a decisive role. In this context, a design flow for the used ASIC is developed. The analyses show that through optimizations the extremely high demands made on this complex system can be met. During a beam time, first prototypes have successfully been tested. The entire system is currently being assembled and will be brought on line in 2008. (orig.)

  3. TRANSIT

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. TRANSIT. SYSTEM: DETERMINE 2D-POSITION GLOBALLY BUT INTERMITTENT (POST-FACTO). IMPROVED ACCURACY. PRINCIPLE: POLAR SATELLITES WITH INNOVATIONS OF: GRAVITY-GRADIENT ATTITUDE CONTROL; DRAG COMPENSATION. WORKS ...

  4. A pixel segmented silicon strip detector for ultra fast shaping at low noise and low power consumption

    International Nuclear Information System (INIS)

    Misiakos, K.; Kavadias, S.

    1996-01-01

    A new radiation imaging device is proposed based on strips segmented into small pixels. Every pixel contains a submicron transistor that is normally biased in weak inversion. The ionization charge, upon collection by the pixel, changes the bias of the transistor to strong inversion and supplies a current up to several tens of a microA. This is a consequence of the small pixel capacitance (12 fF). The drains and sources of the transistors on the same row and column are shorted to bus lines that effectively become the Y and X coordinates. These bus lines are connected to the off chip ICON amplifiers to provide a 10 ns peaking time at a noise of about 150 electrons and 1 nW power consumption, for a 10x10 cm 2 detector and a MIP excitation. The noise performance is dominated by the ICON transistors. The cross talk between adjacent strips can be kept at a few percentage points provided a low transistor bias current is used

  5. Reprint of “Heat capacity and transition behavior of sucrose by standard, fast scanning and temperature-modulated calorimetry”

    Energy Technology Data Exchange (ETDEWEB)

    Magoń, A. [Department of Chemistry, University of Technology, 35-959 Rzeszów (Poland); Wurm, A.; Schick, C. [Department of Physics, University of Rostock, 18057 Rostock (Germany); Pangloli, Ph.; Zivanovic, S. [Department of Food Science and Technology, University of Tennessee, Knoxville, TN 37996 (United States); Skotnicki, M. [Department of Pharmaceutical Technology, Poznan University of Medical Sciences, 60-780 Poznań (Poland); Pyda, M., E-mail: mpyda@utk.edu [Department of Chemistry, University of Technology, 35-959 Rzeszów (Poland)

    2015-03-10

    Highlights: • Experimental, apparent heat capacity of sucrose was investigated by advanced thermal analysis. • Vibrational heat capacity of solid state was linked with a low temperature experimental heat capacity of sucrose. • Equilibrium melting parameters of sucrose were determined. • Decomposition, superheating of crystalline sucrose during melting process were presented. • TGA, DSC, TMDSC, and FSC are useful tools for characterization of sucrose. - Abstract: The heat capacity (C{sub p}) of crystalline and amorphous sucrose was determined using standard and quasi-isothermal temperature modulated differential scanning calorimetry. The results were combined with the published data determined by adiabatic calorimetry, and the C{sub p} values are now reported for the wide 5–600 K range. The experimental C{sub p} of solid sucrose at 5–300 K was used to calculate the vibrational, solid C{sub p} based on the vibrational molecular motions. The calculated solid and liquid C{sub p} together with the transition parameters for equilibrium conditions were used as references for detailed quantitative thermal analysis of crystalline and amorphous sucrose. Melting temperature (T{sub m}) of the crystalline sucrose was identified in a broad 442–465 K range with a heat of fusion of 40–46 J/mol determined at heating rates 0.5–20 K/min, respectively. The equilibrium T{sub m} and heat of fusion of crystalline sucrose were estimated at zero heating rate as T{sup o}{sub m} = 424.4 K and ΔH{sup o}{sub f} = 32 kJ/mol, respectively. The glass transition temperature (T{sub g}) of amorphous sucrose was at 331 K with a change in C{sub p} of 267 J/(mol K) as it was estimated from reversing heat capacity by quasi-isothermal TMDSC on cooling. At heating rates less than 30 K/min, thermal decomposition occurred during melting, while at extreme rate of 1000 K/s, degradation was not observed. Data obtained by fast scanning calorimetry (FSC) at 1000 K/s, showed that T{sub m} was

  6. Present status of fast neutron personnel dosimetry system based on CR-39 solid state nuclear track detectors

    International Nuclear Information System (INIS)

    Pal, Rupali; Sathian, Deepa; Jayalakshmi, V.; Bakshi, A.K.; Chougaonkar, M.P.; Mayya, Y.S.; Kumar, Valli; Babu, Rajesh; Kar, S.; Joshi, V.M.

    2011-08-01

    Neutron sources are of different types depending upon the method of production such as nuclear reactors, particle accelerators and laboratory sources. Neutron sources depending upon their energy, flux, size etc. are used for variety of applications in basic and applied sciences, neutron scattering experiments and in industry such as oil well - digging, coal mining and processing, ore processing etc. Personnel working in nuclear installations such as reactors, accelerators, spent fuel processing plants, nuclear fuel cycle operations and those working in various industries such as oil refining, oil well-digging, coal mining and processing, ore processing, etc. need to be monitored for neutron exposures, if any. Neutron monitoring is especially necessary in view of the fact that the radiation weighting factor for neutron is much higher than gamma rays and also it varies with energy. Radiological Physics and Advisory Division is involved in monitoring of personnel working in neutron fields. Around 2100 workers from 70 institutions (DAE and Non-DAE) are monitored on a quarterly basis. Neutron personnel monitoring, carried out in the country is based on Solid State Nuclear Track Detection (SSNTD) technique. In this technique, neutrons interact with hydrogen in CR-39 polymer to produce recoil protons. These protons create damages in the polymer, which are enlarged and appear as tracks when subjected to electrochemical etching (ECE). These tracks are counted in an optical system to evaluate the neutron dose. The neutron dosimetry system based on SSNTD has undergone a significant development, since it was started in 1990. The development includes upgradation of image analysis system for counting tracks, introduction of chemical etching (CE) at elevated temperatures for evaluation of dose equivalents above 10 mSv and use of carbon laser for cutting of CR-39 detectors. The entire dose evaluation process has been standardized, which includes calibration and performance tests

  7. System to detect contraband in cargo containers using fast and slow neutron irradiation and collimated gamma detectors

    International Nuclear Information System (INIS)

    Smith, R.C.; Hurwitz, M.J.; Tran, K.C.

    1995-01-01

    We have produced a product design concept for an automatic, shipping-container inspection system to be used for detection of contraband, including illicit drugs, and for trade regulation enforcement via shipping manifest confirmation. Using nondestructive nuclear techniques the system can see deeply into the cargo and generate a 3-D spatial image of an entire container's contents automatically and in real time. A pulsed, sealed-tube, neutron generator is employed. The approach divides a container into numerous, small, volume elements that are individually interrogated using concurrent fast and slow neutron activation and gamma detection by collimated scintillators. We have designed, built, and operated a laboratory apparatus which has demonstrated the attractiveness of this approach. Experimental data were found to agree with design expectations derived from computer modeling. By combining selected element signatures and phenomenological measures, together with discrimination algorithms, we have demonstrated that a full-scale inspection system would need from less than 5 min to 30 min (depending on cargo type) to process an 8 ftx8 ftx40 ft container in order to detect hidden contraband. (orig.)

  8. Preliminary results of the experiment on the identification of cosmic hadrons usinq the X-ray transition radiation XTR-detectors

    International Nuclear Information System (INIS)

    Avakyan, R.A.; Avakyan, K.M.; Alikhanyan, A.I.

    1974-01-01

    The spectrum of cosmic hadrons with an energy of 300 GeV or more at the height of 3250 m above the sea level has been studied. The objective has been to determine the Nsub(π)/Nsub(p) ratio at the given energies. The device consists of a 830 g/cm 2 scintillation calorimeter and an X-ray transition radiation detector, comprising three sections of laminated medium each having 200 layers, and multi-filament proportional counters. The lower limit of the Nsub(π)/Nsub(p) ratio has been obtained, it is equal to 0.37+-0.16

  9. Development and evaluation of an ultra-fast ASIC for future PET scanners using TOF-capable MPPC array detectors

    International Nuclear Information System (INIS)

    Ambe, T.; Ikeda, H.; Kataoka, J.; Matsuda, H.; Kato, T.

    2015-01-01

    We developed a front-end ASIC for future PET scanners with Time-Of-Flight (TOF) capability to be coupled with 4×4 Multi-Pixel Photon Counter (MPPC) arrays. The ASIC is designed based on the open-IP project proposed by JAXA and realized in TSMC 0.35 μm CMOS technology. The circuit comprises 16-channel, low impedance current conveyors for effectively acquiring fast MPPC signals. For precise measurement of the coincidence timing of 511-keV gamma rays, the leading-edge method was used to discriminate the signals. We first tested the time response of the ASIC by illuminating each channel of a MPPC array device 3×3 mm 2 in size with a Pico-second Light Pulsar with a light emission peak of 655 nm and pulse duration of 54 ps (FWHM). We obtained 105 ps (FWHM) on average for each channel in time jitter measurements. Moreover, we compensated for the time lag of each channel with inner delay circuits and succeeded in suppressing about a 700-ps lag to only 15 ps. This paper reports TOF measurements using back-to-back 511-keV signals, and suggests that the ASIC can be a promising device for future TOF-PET scanners based on the MPPC array. - Highlights: • We developed a newly designed large-area monolithic MPPC array. • We obtained fine gain uniformity, and good energy and time resolutions when coupled to the LYSO scintillator. • We fabricated gamma-ray camera consisting of the MPPC array and the submillimeter pixelized LYSO and GGAG scintillators. • In the flood images, each crystal of scintillator matrices was clearly resolved. • Good energy resolutions for 662 keV gamma-rays for each LYSO and GGAG scintillator matrices were obtained

  10. Analysis of n-in-p type silicon detectors for high radiation environment with fast analogue and binary readout systems

    Energy Technology Data Exchange (ETDEWEB)

    Printz, Martin

    2016-01-22

    The Large Hadron Collider at CERN is the most powerful particle accelerator ever built. The collision of high intensity proton beams at a center of mass energy of up to 14 TeV allows the exploration of the undiscovered territory at the TeV scale with great detail. The high energy physics frontier covers detailed Standard Model (SM) physics like the search for the SM Higgs boson which has been found in July 2012 but also physics beyond the SM like the Supersymmetry or studies of the quark-gluon plasma. The production rate of certain events is correlated to the instantaneous luminosity which is a measure for the number of detected events with in a certain time with respect to the interaction cross-section. In order to increase the statistics by collecting more data the integrated luminosity is maximized as far as possible. Simultaneously an increase of the particle energy and the luminosity reveals challenging experimental requirements for the trigger and detector systems present at the LHC. After a successful Run 1 of the machine between 2010 and 2013, the energy and the instantaneous luminosity of the machine are sequentially increased up to the last so called Phase II Upgrade planned for the years 2024 and 2025. The high luminosity LHC will provide particle beams with the final 14 TeV center of mass energy at an instantaneous luminosity of 5 x 10{sup 34} cm{sup -2}s{sup -1} which is five to seven times the nominal design luminosity. In the course of the Upgrade, the experiments will face extraordinary radiation environments and particle densities and have to be upgraded as well in order to cope with the challenging demands. The Compact Muon Solenoid (CMS) at CERN is a general purpose experiment with a diverse physics measurement program. It is built of several subdetectors. The most inner part consists of the pixel detector and the silicon strip tracker. The latter will be replaced completely during the Phase II Upgrade by a new layout whereas a different silicon

  11. High Frequency Design Considerations for the Large Detector Number and Small Form Factor Dual Electron Spectrometer of the Fast Plasma Investigation on NASA's Magnetospheric Multiscale Mission

    Science.gov (United States)

    Kujawski, Joseph T.; Gliese, Ulrik B.; Cao, N. T.; Zeuch, M. A.; White, D.; Chornay, D. J; Lobell, J. V.; Avanov, L. A.; Barrie, A. C.; Mariano, A. J.; hide

    2015-01-01

    Each half of the Dual Electron Spectrometer (DES) of the Fast Plasma Investigation (FPI) on NASA's Magnetospheric MultiScale (MMS) mission utilizes a microchannel plate Chevron stack feeding 16 separate detection channels each with a dedicated anode and amplifier/discriminator chip. The desire to detect events on a single channel with a temporal spacing of 100 ns and a fixed dead-time drove our decision to use an amplifier/discriminator with a very fast (GHz class) front end. Since the inherent frequency response of each pulse in the output of the DES microchannel plate system also has frequency components above a GHz, this produced a number of design constraints not normally expected in electronic systems operating at peak speeds of 10 MHz. Additional constraints are imposed by the geometry of the instrument requiring all 16 channels along with each anode and amplifier/discriminator to be packaged in a relatively small space. We developed an electrical model for board level interactions between the detector channels to allow us to design a board topology which gave us the best detection sensitivity and lowest channel to channel crosstalk. The amplifier/discriminator output was designed to prevent the outputs from one channel from producing triggers on the inputs of other channels. A number of Radio Frequency design techniques were then applied to prevent signals from other subsystems (e.g. the high voltage power supply, command and data handling board, and Ultraviolet stimulation for the MCP) from generating false events. These techniques enabled us to operate the board at its highest sensitivity when operated in isolation and at very high sensitivity when placed into the overall system.

  12. Investigations for the use of the fast digitizers with C6D6 detectors for radiative capture measurements at GELINA

    International Nuclear Information System (INIS)

    Mihailescu, L.C.; Borella, A.; Massimi, C.; Schillebeeckx, P.

    2009-01-01

    The relatively long dead time in conventional data acquisition systems that provide simultaneously the pulse height and the time information for the detected events hinders cross-section measurements with high count rates. This is the case for capture cross-section measurements at the time-of-flight facility GELINA using high radioactive samples or thick samples of materials having strong resonances. Either the high average count rate (e.g. due to the radioactivity of the sample) or the high instantaneous count rate for strong resonances results in a large dead time correction. One solution to reduce the impact of the dead time is the use of a data acquisition system based on fast digitizers. The performances of two commercial digitizers (CAEN N172B and Acqiris DC282), coupled to a C 6 D 6 scintillator, have been tested in terms of pulse height linearity and resolution, dead time and time resolution. The signal processing was done on-line obtaining simultaneously the pulse height and time information for each detected event. With both digitizers a comparable pulse height linearity and resolution has been obtained as with a conventional system. The total dead time of both digital systems is at least a factor 5 shorter than the one for the conventional system. The main difference in performance between the two digitizers is the time resolution. For a relatively large scintillator, a time resolution of about 2 ns has been achieved with the DC282 module and the conventional system while the time resolution was limited to 15 ns with the CAEN N1728B module. For most nuclei a 15 ns time resolution is sufficient to perform resonance shape analysis. Therefore, the CAEN N1728B module can be used for the majority of capture cross-section measurements at GELINA. However, for nuclei with low level density, for which the resolved resonance region extends to the keV-region, a better time resolution is required and the Acqiris DC282 module has to be used.

  13. Spiral silicon drift detectors

    International Nuclear Information System (INIS)

    Rehak, P.; Gatti, E.; Longoni, A.; Sampietro, M.; Holl, P.; Lutz, G.; Kemmer, J.; Prechtel, U.; Ziemann, T.

    1988-01-01

    An advanced large area silicon photodiode (and x-ray detector), called Spiral Drift Detector, was designed, produced and tested. The Spiral Detector belongs to the family of silicon drift detectors and is an improvement of the well known Cylindrical Drift Detector. In both detectors, signal electrons created in silicon by fast charged particles or photons are drifting toward a practically point-like collection anode. The capacitance of the anode is therefore kept at the minimum (0.1pF). The concentric rings of the cylindrical detector are replaced by a continuous spiral in the new detector. The spiral geometry detector design leads to a decrease of the detector leakage current. In the spiral detector all electrons generated at the silicon-silicon oxide interface are collected on a guard sink rather than contributing to the detector leakage current. The decrease of the leakage current reduces the parallel noise of the detector. This decrease of the leakage current and the very small capacities of the detector anode with a capacitively matched preamplifier may improve the energy resolution of Spiral Drift Detectors operating at room temperature down to about 50 electrons rms. This resolution is in the range attainable at present only by cooled semiconductor detectors. 5 refs., 10 figs

  14. Development of the control system of the ALICE Transition Radiation Detector and of a test environment for quality-assurance of its front-end electronics

    CERN Document Server

    Mercado Pérez, Jorge

    2008-01-01

    Within this thesis, the detector control system (DCS) for the Transition Radiation Detector (TRD) of the ALICE experiment at the Large Hadron Collider has been developed. The TRD DCS is fully implemented as a detector oriented hierarchy of objects behaving as finite state machines. It controls and monitors over 65 thousand front-end electronics (FEE) units, a few hundred low voltage and one thousand high voltage channels, and other sub-systems such as cooling and gas. Commissioning of the TRD DCS took place during several runs with ALICE using cosmic events. Another part of this thesis describes the development of a test environment for large-scale production quality-assurance of over 4 thousand FEE read-out boards containing in total about 1.2 million read-out channels. The hardware and software components are described in detail. Additionally, a series of performance studies were carried out earlier including radiation tolerance tests of the TRAP chip which is the core component of the TRD FEE.

  15. Development of the control system of the ALICE transition radiation detector and of a test environment for quality-assurance of its front-end electronics

    International Nuclear Information System (INIS)

    Mercado Perez, Jorge

    2008-01-01

    Within this thesis, the detector control system (DCS) for the Transition Radiation Detector (TRD) of the ALICE experiment at the Large Hadron Collider has been developed. The TRD DCS is fully implemented as a detector oriented hierarchy of objects behaving as finite state machines. It controls and monitors over 65 thousand front-end electronics (FEE) units, a few hundred low voltage and one thousand high voltage channels, and other sub-systems such as cooling and gas. Commissioning of the TRD DCS took place during several runs with ALICE using cosmic events. Another part of this thesis describes the development of a test environment for large-scale production quality-assurance of over 4 thousand FEE read-out boards containing in total about 1.2 million read-out channels. The hardware and software components are described in detail. Additionally, a series of performance studies were carried out earlier including radiation tolerance tests of the TRAP chip which is the core component of the TRD FEE. (orig.)

  16. Development of the control system of the ALICE transition radiation detector and of a test environment for quality-assurance of its front-end electronics

    Energy Technology Data Exchange (ETDEWEB)

    Mercado Perez, Jorge

    2008-11-10

    Within this thesis, the detector control system (DCS) for the Transition Radiation Detector (TRD) of the ALICE experiment at the Large Hadron Collider has been developed. The TRD DCS is fully implemented as a detector oriented hierarchy of objects behaving as finite state machines. It controls and monitors over 65 thousand front-end electronics (FEE) units, a few hundred low voltage and one thousand high voltage channels, and other sub-systems such as cooling and gas. Commissioning of the TRD DCS took place during several runs with ALICE using cosmic events. Another part of this thesis describes the development of a test environment for large-scale production quality-assurance of over 4 thousand FEE read-out boards containing in total about 1.2 million read-out channels. The hardware and software components are described in detail. Additionally, a series of performance studies were carried out earlier including radiation tolerance tests of the TRAP chip which is the core component of the TRD FEE. (orig.)

  17. Hard X-ray polarimetry with position sensitve germanium detectors. Studies of the recombination transitions into highly charged ions

    Energy Technology Data Exchange (ETDEWEB)

    Tashenov, Stanislav

    2005-07-01

    In this work a first study of the photon polarization for the process of radiative recombination has been performed. This was done at the ESR storage ring at GSI for uranium ions colliding with N2 at various collision energies. For this measurement a high purity Ge Pixel Detector with a 4 x 4 segmentation matrix was applied. The investigation was performed at the Gas-jet target of the ESR. The detector was placed at 60 and 90 observation angles. The sensitivity of the Compton scattering effect to the linear polarization of the X-Ray radiation was employed for the polarization measurement. Detailed investigations of the scattering and geometrical effects inside the detector were performed in order to develop a method to interpret the experimental data and extract the degree of the linear polarization in the hard X-Ray regime with a high precision. A special emphasis was given to the geometry of the detector and it's influence on the measured pixel-to-pixel Compton scattering intensities. The developed method enabled to achieve a precision of the order of 10% with the Pixel Detector which is dominated by the statistical uncertainties. The obtained results show a good agreement with the theoretical values derived from the exact relativistic calculations. For the case of the linear polarization of the K-REC photons, the measured data con rm the theoretical prediction that strong depolarization effects occur for high projectile charges in the forward hemisphere. The latter is in disagreement with the nonrelativistic theory which predicts a 100 % polarization regardless of the emission angle. (orig.)

  18. Hard X-ray polarimetry with position sensitve germanium detectors. Studies of the recombination transitions into highly charged ions

    International Nuclear Information System (INIS)

    Tashenov, Stanislav

    2005-01-01

    In this work a first study of the photon polarization for the process of radiative recombination has been performed. This was done at the ESR storage ring at GSI for uranium ions colliding with N2 at various collision energies. For this measurement a high purity Ge Pixel Detector with a 4 x 4 segmentation matrix was applied. The investigation was performed at the Gas-jet target of the ESR. The detector was placed at 60 and 90 observation angles. The sensitivity of the Compton scattering effect to the linear polarization of the X-Ray radiation was employed for the polarization measurement. Detailed investigations of the scattering and geometrical effects inside the detector were performed in order to develop a method to interpret the experimental data and extract the degree of the linear polarization in the hard X-Ray regime with a high precision. A special emphasis was given to the geometry of the detector and it's influence on the measured pixel-to-pixel Compton scattering intensities. The developed method enabled to achieve a precision of the order of 10% with the Pixel Detector which is dominated by the statistical uncertainties. The obtained results show a good agreement with the theoretical values derived from the exact relativistic calculations. For the case of the linear polarization of the K-REC photons, the measured data con rm the theoretical prediction that strong depolarization effects occur for high projectile charges in the forward hemisphere. The latter is in disagreement with the nonrelativistic theory which predicts a 100 % polarization regardless of the emission angle. (orig.)

  19. Causal impact of magnetic fluctuations in slow and fast L–H transitions at TJ-II

    Energy Technology Data Exchange (ETDEWEB)

    Milligen, B. Ph. van; Estrada, T.; Ascasíbar, E.; Hidalgo, C.; Pastor, I.; Fontdecaba, J. M. [Laboratorio Nacional de Fusion, CIEMAT, Avda. Complutense 40, 28040 Madrid (Spain); Carreras, B. A. [BACV Solutions, 110 Mohawk Road, Oak Ridge, Tennessee 37830 (United States); Balbín, R. [Instituto Español de Oceanografía, Centro Oceanográfico de Baleares, Muelle de Poniente s/n, 07015 Palma de Mallorca (Spain)

    2016-07-15

    This work focuses on the relationship between L–H (or L–I) transitions and MHD activity in the low magnetic shear TJ-II stellarator. It is shown that the presence of a low order rational surface in the plasma edge (gradient) region lowers the threshold density for H-mode access. MHD activity is systematically suppressed near the confinement transition. We apply a causality detection technique (based on the Transfer Entropy) to study the relation between magnetic oscillations and locally measured plasma rotation velocity (related to Zonal Flows). For this purpose, we study a large number of discharges in two magnetic configurations, corresponding to “fast” and “slow” transitions. With the “slow” transitions, the developing Zonal Flow prior to the transition is associated with the gradual reduction of magnetic oscillations. The transition itself is marked by a strong spike of “information transfer” from magnetic to velocity oscillations, suggesting that the magnetic drive may play a role in setting up the final sheared flow responsible for the H-mode transport barrier. Similar observations were made for the “fast” transitions. Thus, it is shown that magnetic oscillations associated with rational surfaces play an important and active role in confinement transitions, so that electromagnetic effects should be included in any complete transition model.

  20. Methods for determining fast neutron spectra using threshold detectors; Les methodes de determination des spectres de neutrons rapides a l'aide de detecteurs a seuil

    Energy Technology Data Exchange (ETDEWEB)

    Delattre, P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1961-07-01

    We propose to examine all the methods by which fast neutron spectra can be determined using the response of threshold detectors (activation or fission chamber detectors). Most of these methods have been proposed and often even used by various authors of which a list will be found in the bibliography. The aim of the present report is thus not to present original work but rather to gather into a single article and to present in a rational form a whole series of methods which have already been described in articles scattered throughout the specialised literature. Up to the present, each author has in general studied one or two methods and no comparative study of all the possible methods seems to have been made. The most comprehensive study on this topic is that of P.M. UTHE from whose article much has been borrowed. We have tried here to develop a useful tool which should facilitate the systematic experimental study leading to the recognition of the respective merits of the methods proposed. (author) [French] On se propose d'examiner l'ensemble des methodes permettant de determiner les spectres de neutrons rapides a partir des reponses de detecteurs a seuil (detecteurs par activation ou chambre a fission). La plupart de ces methodes ont deja ete proposees, et souvent meme utilisees, par differents auteurs dont on trouvera la liste en bibliographie. Le but du present rapport n'est donc pas de faire oeuvre originale mais plutot de rassembler dans un meme document et de presenter de maniere homogene toute une serie de methodes qui ont deja fait l'objet d'articles disperses dans la litterature specialisee. Jusqu'a present, chaque auteur s'est en general limite a l'etude experimentale d'une ou deux methodes et aucune etude comparative de l'ensemble des methodes possibles ne semble avoir ete faite. Le rapport le plus complet a ce sujet est celui de P.M. UTHE auquel de larges emprunts ont ete faits. On s'est efforce ici d'elaborer un outil de travail commode qui devrait

  1. How fast are the ultra-fast nano-scale solid-liquid phase transitions induced by energetic particles in solids?

    International Nuclear Information System (INIS)

    Lopasso, E.M.; Caro, A.; Caro, M.

    2003-01-01

    We study the thermodynamic forces acting on the evolution of the nanoscale regions excited by collisions of energetic particles into solid targets. We analyze the role of diffusion, thermo-migration, and the liquidus-solidus two-phase field crossing, as the system cools down from the collision-induced melt under different conditions of energy deposition. To determine the relevance of these thermodynamic forces, solute redistribution is evaluated using molecular dynamics simulations of equilibrium Au-Ni solid solutions. At low collision energies, our results show that the quenching of spherical cascades is too fast to allow for solute redistribution according to equilibrium solidification as determined from the equilibrium phase diagram (zone refining effect), and only thermo-migration is observed. At higher energies instead, in the cylindrical symmetry of ion tracks, quenching rate is in a range that shows the combined effects of thermo-migration and solute redistribution that, depending on the material, can reinforce or cancel each other. These results are relevant for the interpretation of the early stage of radiation damage in alloys, and show that the combination of ultra-fast but nano-scale characteristics of these processes can still be described in terms of linear response of the perturbed system

  2. Cosmic Microwave Background Polarization Detector with High Efficiency, Broad Bandwidth, and Highly Symmetric Coupling to Transition Edge Sensor Bolometers

    Science.gov (United States)

    Wollack, E.; Cao, N.; Chuss, D.; Denis, K.; Hsieh, W.-T.; Moseley, S. Harvey; Schneider, G.; Stevenson, T.; Travers, D.; U-yen, K.

    2008-01-01

    Four probe antennas transfer signals from waveguide to microstrip lines. The probes not only provide broadband impedance matching, but also thermally isolate waveguide and detector. In addition, we developed a new photonic waveguide choke joint design, with four-fold symmetry, to suppress power leakage at the interface. We have developed facilities to test superconducting circuit elements using a cryogenic microwave probe station, and more complete systems in waveguide. We used the ring resonator shown below to measure a dielectric loss tangent 99% coupling efficiency over 30% fractional bandwidth.

  3. Measurement of the unaccompanied pion-proton flux ratio at 2,900 meters using a transition radiation detector

    International Nuclear Information System (INIS)

    Ellsworth, R.W.; Ito, A.S.; MacFall, J.R.; Siohan, F.; Streitmatter, R.E.; Tonwar, S.C.; Yodh, G.B.

    1975-01-01

    A transition radiation dedector and an ionization calorimeter have been used to measure the unaccompanied pion to proton flux ratio for energies greater than 400 and 600 GeV at an altitude of 2,900 meters. (orig./BJ) [de

  4. Second-order quadrupolar line shapes under molecular dynamics: An additional transition in the extremely fast regime.

    Science.gov (United States)

    Hung, Ivan; Wu, Gang; Gan, Zhehong

    NMR spectroscopy is a powerful tool for probing molecular dynamics. For the classic case of two-site exchange, NMR spectra go through the transition from exchange broadening through coalescence and then motional narrowing as the exchange rate increases passing through the difference between the resonance frequencies of the two sites. For central-transition spectra of half-integer quadrupolar nuclei in solids, line shape change due to molecular dynamics occurs in two stages. The first stage occurs when the exchange rate is comparable to the second-order quadrupolar interaction. The second spectral transition comes at a faster exchange rate which approaches the Larmor frequency and generally reduces the isotropic quadrupolar shift. Such a two-stage transition phenomenon is unique to half-integer quadrupolar nuclei. A quantum mechanical formalism in full Liouville space is presented to explain the physical origin of the two-stage phenomenon and for use in spectral simulations. Variable-temperature 17 O NMR of solid NaNO 3 in which the NO 3 - ion undergoes 3-fold jumps confirms the two-stage transition process. The spectra of NaNO 3 acquired in the temperature range of 173-413K agree well with simulations using the quantum mechanical formalism. The rate constants for the 3-fold NO 3 - ion jumps span eight orders of magnitude (10 2 -10 10 s -1 ) covering both transitions of the dynamic 17 O line shape. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Vertex detectors

    International Nuclear Information System (INIS)

    Lueth, V.

    1992-07-01

    The purpose of a vertex detector is to measure position and angles of charged particle tracks to sufficient precision so as to be able to separate tracks originating from decay vertices from those produced at the interaction vertex. Such measurements are interesting because they permit the detection of weakly decaying particles with lifetimes down to 10 -13 s, among them the τ lepton and charm and beauty hadrons. These two lectures are intended to introduce the reader to the different techniques for the detection of secondary vertices that have been developed over the past decades. The first lecture includes a brief introduction to the methods used to detect secondary vertices and to estimate particle lifetimes. It describes the traditional technologies, based on photographic recording in emulsions and on film of bubble chambers, and introduces fast electronic registration of signals derived from scintillating fibers, drift chambers and gaseous micro-strip chambers. The second lecture is devoted to solid state detectors. It begins with a brief introduction into semiconductor devices, and then describes the application of large arrays of strip and pixel diodes for charged particle tracking. These lectures can only serve as an introduction the topic of vertex detectors. Time and space do not allow for an in-depth coverage of many of the interesting aspects of vertex detector design and operation

  6. Calibration of the ALICE transition radiation detector and a study of Z{sup 0} and heavy quark production in pp colissions at the LHC

    Energy Technology Data Exchange (ETDEWEB)

    Bailhache, Raphaelle

    2009-01-28

    The ALICE Experiment is one of the four experiments installed at the Large Hadron Collider (LHC). One of its detector-systems, the Transition Radiation Detector (TRD), is a gas detector designed for electron identification and charged particle tracking. The charged particle ionizes the gas along its path and electrons drift in an uniform field of 700 V/cm over 3 cm before being amplified. We implemented procedures to calibrate the drift velocity of the electrons, the time-offset of the signal, the amplification factor and the width of the Pad Response Function (PDF) characterizing the sharing of the deposited charge over adjacent pads. Physics events (pp and PbPb collisions) will be used. The performances of the algorithms were tested on simulated pp collisions at {radical}(s)=14 TeV and on first real data taken with cosmic-rays in the ALICE setup. The calibration software was installed on the Data Acquisition System at CERN and executed continuously during the cosmic-ray data taking in 2008, providing a first determination of the calibration constants. This thesis presents also a study on the capability of the ALICE central barrel to detect the Z{sup 0} boson through the decay Z{sup 0}{yields}e{sup +}e{sup -} in pp collisions at 14 TeV. We demonstrated that the Z{sup 0}{yields}e{sup +}e{sup -} is characterized by a very clean signal in the dielectron reconstructed invariant mass spectrum. At such high transverse momentum (about 45 GeV/c), the electrons from Z{sup 0} are identified with the Transition Radiation Detector. The remaining background from misidentified pions and electrons from heavy-flavored decays are rejected by the requirement of two isolated reconstructed tracks. The main challenge comes from the very small production rate. Therefore we estimated the efficiency of a trigger based on a low p{sub T} cut and electron identification with the TRD and showed that about 100 Z{sup 0}{yields}e{sup +}e{sup -} can be reconstructed per year employing such a

  7. Calibration of the ALICE transition radiation detector and a study of Z0 and heavy quark production in pp collisions at the LHC

    International Nuclear Information System (INIS)

    Bailhache, Raphaelle

    2009-01-01

    The ALICE Experiment is one of the four experiments installed at the Large Hadron Collider (LHC). One of its detector-systems, the Transition Radiation Detector (TRD), is a gas detector designed for electron identification and charged particle tracking. The charged particle ionizes the gas along its path and electrons drift in an uniform field of 700 V/cm over 3 cm before being amplified. We implemented procedures to calibrate the drift velocity of the electrons, the time-offset of the signal, the amplification factor and the width of the Pad Response Function (PDF) characterizing the sharing of the deposited charge over adjacent pads. Physics events (pp and PbPb collisions) will be used. The performances of the algorithms were tested on simulated pp collisions at √(s)=14 TeV and on first real data taken with cosmic-rays in the ALICE setup. The calibration software was installed on the Data Acquisition System at CERN and executed continuously during the cosmic-ray data taking in 2008, providing a first determination of the calibration constants. This thesis presents also a study on the capability of the ALICE central barrel to detect the Z 0 boson through the decay Z 0 →e + e - in pp collisions at 14 TeV. We demonstrated that the Z 0 →e + e - is characterized by a very clean signal in the dielectron reconstructed invariant mass spectrum. At such high transverse momentum (about 45 GeV/c), the electrons from Z 0 are identified with the Transition Radiation Detector. The remaining background from misidentified pions and electrons from heavy-flavored decays are rejected by the requirement of two isolated reconstructed tracks. The main challenge comes from the very small production rate. Therefore we estimated the efficiency of a trigger based on a low p T cut and electron identification with the TRD and showed that about 100 Z 0 →e + e - can be reconstructed per year employing such a trigger. Another physics topics investigated in this thesis is the measurement

  8. Upgrade of the Level-1 muon trigger of the ATLAS detector in the barrel-endcap transition region with RPC chambers

    CERN Document Server

    Massa, L; The ATLAS collaboration

    2014-01-01

    This report presents a project for the upgrade of the Level-1 muon trigger in the barrel-endcap transition region (1.01) caused by charged particles originating from secondary interactions downstream of the interaction point. After the LHC phase-1 upgrade, forseen for 2018, the Level-1 muon trigger rate would saturate the allocated bandwidth unless new measures are adopted to improve the rejection of fake triggers. ATLAS is going to improve the trigger selectivity in the region |$\\eta$|>1.3 with the addition of the New Small Wheel detector as an inner trigger plane. To obtain a similar trigger selectivity in the barrel-endcap transition region 1.0<|$\\eta$|<1.3, it is proposed to add new RPC chambers at the edge of the inner layer of the barrel muon spectrometer. These chambers will be based on a three layer structure with thinner gas gaps and electrodes with respect to the ATLAS standard and a new low-profile light-weight mechanical structure that will allow the installation in the limited available spa...

  9. A massive cryogenic particle detector with good energy resolution

    International Nuclear Information System (INIS)

    Ferger, P.; Colling, P.; Cooper, S.; Dummer, D.; Frank, M.; Nagel, U.; Nucciotti, A.; Proebst, F.; Seidel, W.

    1993-12-01

    Massive cryogenic particle detectors are being developed for use in a search for dark matter particles. Results with a 31 g sapphire crystal and a superconducting phase transition thermometer operated at 44 mK are presented. The observed signal includes a fast component which is significantly larger than the expected thermal pulse. The energy resolution is 210 eV (FWHM) for 6 keV X-rays. (orig.)

  10. The discrimination between cosmic positrons and protons with the Transition Radiation Detector of the AMS experiment on the International Space Station

    International Nuclear Information System (INIS)

    Millinger, Mark

    2012-01-01

    The aim of this thesis is the development and validation of a particle identification method with the Transition Radiation Detector (TRD) of the Alpha Magnetic Spectrometer AMS-02 to allow for the determination of the positron fraction in the cosmic lepton flux. Independent measurements indicate that a significant amount of about 23% of the energy density in the universe consists of an unknown mass contribution, the so-called Dark Matter. The Neutralino, as the most popular Dark Matter particle candidate, may produce an additional signal in the spectrum of cosmic rays. The fraction of positrons in the cosmic lepton flux possibly contains such a Dark Matter signal at high particle momenta. The currently most precise measurements in the region of this excess are provided by the satellite-borne PAMELA and Fermi detectors. Momentumdependent systematic uncertainties, especially the mis-identification of protons as positrons, could imitate the signal. However, if this positron excess is produced by Dark Matter the fraction should decrease above a theoretical energy threshold to the expectations, based on particle propagation. The energy region measured up to now does not show such a progress. Due to its significantly increased event statistics and its capability to measure up to higher particle energies, this signature could be observed with AMS-02. The number of events, which can be recorded by a detector, is limited by the combination of aperture and observable solid angle, quantified by the geometrical acceptance, and the observation time. As the cosmic particle flux follows a power-law in particle momentum with exponent γ ∼ -3, the observable momentum interval is thus constrained by statistics. Due to its large geometrical acceptance of about 0.5 m 2 sr, its long observation time of at least 9 years and its high proton suppression factor of >or similar 10 6 AMS-02 will record large and clean lepton samples and thus provide a precise measurement of the cosmic

  11. The discrimination between cosmic positrons and protons with the Transition Radiation Detector of the AMS experiment on the International Space Station

    Energy Technology Data Exchange (ETDEWEB)

    Millinger, Mark

    2012-10-08

    The aim of this thesis is the development and validation of a particle identification method with the Transition Radiation Detector (TRD) of the Alpha Magnetic Spectrometer AMS-02 to allow for the determination of the positron fraction in the cosmic lepton flux. Independent measurements indicate that a significant amount of about 23% of the energy density in the universe consists of an unknown mass contribution, the so-called Dark Matter. The Neutralino, as the most popular Dark Matter particle candidate, may produce an additional signal in the spectrum of cosmic rays. The fraction of positrons in the cosmic lepton flux possibly contains such a Dark Matter signal at high particle momenta. The currently most precise measurements in the region of this excess are provided by the satellite-borne PAMELA and Fermi detectors. Momentumdependent systematic uncertainties, especially the mis-identification of protons as positrons, could imitate the signal. However, if this positron excess is produced by Dark Matter the fraction should decrease above a theoretical energy threshold to the expectations, based on particle propagation. The energy region measured up to now does not show such a progress. Due to its significantly increased event statistics and its capability to measure up to higher particle energies, this signature could be observed with AMS-02. The number of events, which can be recorded by a detector, is limited by the combination of aperture and observable solid angle, quantified by the geometrical acceptance, and the observation time. As the cosmic particle flux follows a power-law in particle momentum with exponent {gamma} {approx} -3, the observable momentum interval is thus constrained by statistics. Due to its large geometrical acceptance of about 0.5 m{sup 2}sr, its long observation time of at least 9 years and its high proton suppression factor of >or similar 10{sup 6} AMS-02 will record large and clean lepton samples and thus provide a precise measurement

  12. Design and realization of a fast low noise electronics for a hybrid pixel X-ray detector dedicated to small animal imaging

    International Nuclear Information System (INIS)

    Chantepie, Benoit

    2008-01-01

    Since the invention of computerized tomography (CT), charge integration detector were widely employed for X-ray biomedical imaging applications. Nevertheless, other options exist. A new technology of direct detection using semiconductors has been developed for high energy physics instrumentation. This new technology, called hybrid pixel detector, works in photon counting mode and allows for selecting the minimum energy of the counted photons. The imXgam research team at CPPM develops the PIXSCAN demonstrator, a CT-scanner using the hybrid pixel detector XPAD. The aim of this project is to evaluate the improvement on image quality and on dose delivered during X-ray examinations of a small animal. After a first prototype of hybrid pixel detector XPAD1 proving the feasibility of the project, a complete imager XPAD2 was designed and integrated in the PIXSCAN demonstrator. Since then, with the evolution of microelectronic industry, important improvements are conceivable. To reducing the size of pixels and to improving the energy resolution of detectors, a third design XPAD3 was conceived and will be soon integrated in a second generation of PIXSCAN demonstrator. In this project, my thesis's work consisted in taking part to the design of the detector readout electronics, to the characterization of the chips and of the hybrid pixel detectors, and also to the definition of an auto-zeroing architecture for pixels. (author) [fr

  13. Drastic increase of myosin light chain MLC-2 in senescent skeletal muscle indicates fast-to-slow fibre transition in sarcopenia of old age.

    Science.gov (United States)

    Gannon, Joan; Doran, Philip; Kirwan, Anne; Ohlendieck, Kay

    2009-11-01

    The age-dependent decline in skeletal muscle mass and function is believed to be due to a multi-factorial pathology and represents a major factor that blocks healthy aging by increasing physical disability, frailty and loss of independence in the elderly. This study has focused on the comparative proteomic analysis of contractile elements and revealed that the most striking age-related changes seem to occur in the protein family representing myosin light chains (MLCs). Comparative screening of total muscle extracts suggests a fast-to-slow transition in the aged MLC population. The mass spectrometric analysis of the myofibril-enriched fraction identified the MLC2 isoform of the slow-type MLC as the contractile protein with the most drastically changed expression during aging. Immunoblotting confirmed an increased abundance of slow MLC2, concomitant with a switch in fast versus slow myosin heavy chains. Staining of two-dimensional gels of crude extracts with the phospho-specific fluorescent dye ProQ-Diamond identified the increased MLC2 spot as a muscle protein with a drastically enhanced phosphorylation level in aged fibres. Comparative immunofluorescence microscopy, using antibodies to fast and slow myosin isoforms, confirmed a fast-to-slow transformation process during muscle aging. Interestingly, the dramatic increase in slow MLC2 expression was restricted to individual senescent fibres. These findings agree with the idea that aged skeletal muscles undergo a shift to more aerobic-oxidative metabolism in a slower-twitching fibre population and suggest the slow MLC2 isoform as a potential biomarker for fibre type shifting in sarcopenia of old age.

  14. Fast wettability transition from hydrophilic to superhydrophobic laser-textured stainless steel surfaces under low-temperature annealing

    Science.gov (United States)

    Ngo, Chi-Vinh; Chun, Doo-Man

    2017-07-01

    Recently, the fabrication of superhydrophobic metallic surfaces by means of pulsed laser texturing has been developed. After laser texturing, samples are typically chemically coated or aged in ambient air for a relatively long time of several weeks to achieve superhydrophobicity. To accelerate the wettability transition from hydrophilicity to superhydrophobicity without the use of additional chemical treatment, a simple annealing post process has been developed. In the present work, grid patterns were first fabricated on stainless steel by a nanosecond pulsed laser, then an additional low-temperature annealing post process at 100 °C was applied. The effect of 100-500 μm step size of the textured grid upon the wettability transition time was also investigated. The proposed post process reduced the transition time from a couple of months to within several hours. All samples showed superhydrophobicity with contact angles greater than 160° and sliding angles smaller than 10° except samples with 500 μm step size, and could be applied in several potential applications such as self-cleaning and control of water adhesion.

  15. 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

  16. Reduced γ–γ time walk to below 50 ps using the multiplexed-start and multiplexed-stop fast-timing technique with LaBr_3(Ce) detectors

    International Nuclear Information System (INIS)

    Régis, J.-M.; Saed-Samii, N.; Rudigier, M.; Ansari, S.; Dannhoff, M.; Esmaylzadeh, A.; Fransen, C.; Gerst, R.-B.; Jolie, J.; Karayonchev, V.; Müller-Gatermann, C.; Stegemann, S.

    2016-01-01

    The electronic γ–γ fast-timing technique using arrays consisting of many LaBr_3(Ce) detectors is a powerful method to determine lifetimes of nuclear excited states with a lower limit of about 5 ps. This method requires the determination of the energy-dependent time walk of the zero time which is represented by the centroid of a prompt γ–γ time distribution. The full-energy peak versus full-energy peak prompt response difference which represents the linearly combined mean γ–γ time walk of a fast-timing array consisting of 8 LaBr_3(Ce) detectors was measured using a standard "1"5"2Eu γ-ray source for the energy region of 40–1408 keV. The data were acquired using a “multiplexed-start and multiplexed-stop” analogue electronics circuitry and analysed by employing the generalized centroid difference method. Concerning the cylindrical 1.5 in.×1.5 in. LaBr_3(Ce) crystals which are coupled to the Hamamatsu R9779 photomultiplier tubes, the best fast-timing array time resolution of 202(3) ps is obtained for the two prompt γ lines of "6"0Co by using the leading-edge timing principle. When using the zero-crossover timing principle the time resolution is degraded by up to 30%, dependent on the energy and the shaping delay time of the constant fraction discriminator model Ortec 935. The smallest γ–γ time walk to below 50 ps is obtained by using a shaping delay time of about 17 ns and an optimum “time-walk adjustment” needed for detector output pulses with amplitudes smaller than 400 mV.

  17. Reduced γ–γ time walk to below 50 ps using the multiplexed-start and multiplexed-stop fast-timing technique with LaBr{sub 3}(Ce) detectors

    Energy Technology Data Exchange (ETDEWEB)

    Régis, J.-M., E-mail: regis@ikp.uni-koeln.de [Institut für Kernphysik der Universität zu Köln, Zülpicher Str. 77, 50937 Köln (Germany); Saed-Samii, N., E-mail: nima@ikp.uni-koeln.de [Institut für Kernphysik der Universität zu Köln, Zülpicher Str. 77, 50937 Köln (Germany); Rudigier, M. [Institut für Kernphysik der Universität zu Köln, Zülpicher Str. 77, 50937 Köln (Germany); Department of Physics, University of Surrey, Guildford GU2 7XH (United Kingdom); Ansari, S.; Dannhoff, M.; Esmaylzadeh, A.; Fransen, C.; Gerst, R.-B.; Jolie, J.; Karayonchev, V.; Müller-Gatermann, C.; Stegemann, S. [Institut für Kernphysik der Universität zu Köln, Zülpicher Str. 77, 50937 Köln (Germany)

    2016-07-01

    The electronic γ–γ fast-timing technique using arrays consisting of many LaBr{sub 3}(Ce) detectors is a powerful method to determine lifetimes of nuclear excited states with a lower limit of about 5 ps. This method requires the determination of the energy-dependent time walk of the zero time which is represented by the centroid of a prompt γ–γ time distribution. The full-energy peak versus full-energy peak prompt response difference which represents the linearly combined mean γ–γ time walk of a fast-timing array consisting of 8 LaBr{sub 3}(Ce) detectors was measured using a standard {sup 152}Eu γ-ray source for the energy region of 40–1408 keV. The data were acquired using a “multiplexed-start and multiplexed-stop” analogue electronics circuitry and analysed by employing the generalized centroid difference method. Concerning the cylindrical 1.5 in.×1.5 in. LaBr{sub 3}(Ce) crystals which are coupled to the Hamamatsu R9779 photomultiplier tubes, the best fast-timing array time resolution of 202(3) ps is obtained for the two prompt γ lines of {sup 60}Co by using the leading-edge timing principle. When using the zero-crossover timing principle the time resolution is degraded by up to 30%, dependent on the energy and the shaping delay time of the constant fraction discriminator model Ortec 935. The smallest γ–γ time walk to below 50 ps is obtained by using a shaping delay time of about 17 ns and an optimum “time-walk adjustment” needed for detector output pulses with amplitudes smaller than 400 mV.

  18. Mixture formation of direct gasoline injection engine. In cylinder gas sampling using fast response ionization detector; Tonai funsha gasoline engine no kongoki keisei. Kosoku FID ni yoru tonai gas sampling

    Energy Technology Data Exchange (ETDEWEB)

    Yamashita, H; Marubara, M; Ota, N; Kudo, H; Yamamoto, H [Mazda Motor Corp., Hiroshima (Japan)

    1997-10-01

    Local mixture concentration near the spark plug of a direct gasoline injection engine was observed by a fast flame ionization detector. To ensure combustion stability and good fuel economy in DISC operation, the swirl ratio and the piston configuration were optimized. Swirl is needed to retain well-vaporized and stable mixture near the spark plug especially in light load. And adequate volume in piston cavity is required for trapping curved fuel spray in it. With these specifications, the fuel economy improvement of 13 to 30 % was realized. 2 refs., 13 figs., 1 tab.

  19. Design and realization of a fast low noise electronics for a hybrid pixel X-ray detector dedicated to small animal imaging

    International Nuclear Information System (INIS)

    Chantepie, B.

    2008-12-01

    Since the invention of computerized tomography (CT), charge integration detector were widely employed for X-ray biomedical imaging applications. Nevertheless, other options exist. A new technology of direct detection using semiconductors has been developed for high energy physics instrumentation. This new technology, called hybrid pixel detector, works in photon counting mode and allows for selecting the minimum energy of the counted photons. The ImXgam research team at CPPM develops the PIXSCAN demonstrator, a CT-scanner using the hybrid pixel detector XPAD. The aim of this project is to evaluate the improvement in image quality and in dose delivered during X-ray examinations of a small animal. After a first prototype of a hybrid pixel detector XPAD1 proving the feasibility of the project, a complete imager XPAD2 was designed and integrated in the PIXSCAN demonstrator. Since then, with the evolution of microelectronic industry, important improvements are conceivable. To reducing the size of pixels and to improving the energy resolution of detectors, a third design XPAD3 was conceived and will be soon integrated in a second generation of PIXSCAN demonstrator. In this project, my thesis work consisted in taking part to the design of the detector readout electronics, to the characterization of the chips and of the hybrid pixel detectors, and also to the definition of a auto-zeroing architecture for pixels. The first and second chapters present X-ray medical imaging and particle detection with semi-conductors and its modelling. The third chapter deals with the specifications of electronic circuits for imaging applications first for analog pixels then for digital pixels and describes the general architecture of the integrated circuits. The validation tests are presented in the fourth chapter while the last chapter gives an account of expected changes in pixel electronics

  20. Effects of an in vacancy on local distortion of fast phase transition in Bi-doped In3SbTe2

    Science.gov (United States)

    Choi, Minho; Choi, Heechae; Kim, Seungchul; Ahn, Jinho; Kim, Yong Tae

    2017-12-01

    Indium vacancies in Bi-doped In3SbTe2 (BIST) cause local distortion or and faster phase transition of BIST with good stability. The formation energy of the In vacancy in the BIST is relatively lower compared to that in IST due to triple negative charge state of the In vacancy ( V 3- In) and higher concentration of the V 3- In in BIST. The band gap of BIST is substantially reduced with increasing concentrations of the V 3- In and the hole carriers, which results in a higher electrical conductivity. The phase-change memory (PRAM) device fabricated with the BIST shows very fast, stable switching characteristics at lower voltages.

  1. Development, simulation and test of transition radiation detector prototypes for the compressed baryonic matter experiment at the facility for antiproton and ion research

    Energy Technology Data Exchange (ETDEWEB)

    Bergmann, Cyrano S.H.

    2014-07-01

    The focus of this thesis is the development of a Transition Radiation Detector (TRD) for the Compressed Baryonic Matter (CBM) experiment at FAIR. The TRD sub-detector will contribute to the global particle identification and track reconstruction of charged particles. The technical design goal for the TRD is to identify 90% electrons with a maximum pion contamination of 1%. The TRD and Ring Image CHerenkov (RICH) detector should reach a common pion rejection of 10{sup 4}, in order to measure charmonium and low-mass vector mesons. The position resolution should be between 200 and 300 μm in the anode wire direction. The most demanding aspect of the CBM TRD design is the high interaction rate of up to 10{sup 7} Hz resulting in a charged particle rate of up to 100 kHz/cm{sup 2} in the central part of the detector planes at SIS300 conditions. It is crucial to find the optimal radiator detector combination with a minimum material budget to limit scattering and background due to conversions and at the same time reach a sufficient pion rejection and position resolution. In this thesis it is confirmed that a Multi-Wire Proportional Counter (MWPC) with a Xe/CO{sub 2} gas thickness of 12mm provides sufficient absorption probability for TR-photons in combination with self-supporting low density PE foam or micro-structured foil radiators. A continuous investigation aiming at an optimal wire and pad-plane geometry, as well as a minimization of the material budget between active gas and radiator has been presented in hard- and software. A minimum photon absorption cross-section of the entrance window was realized with a thermally stretched aluminized Kapton foil, glued to a G11 support grid support frame. This structure limits the mechanical deformation of the entire window to 1mm/mbar. All MWPC prototypes include two wire planes. A symmetric amplification region of 2 x (3, 3.5 or 4)mm is followed by a short drift region of 6, 5 or 4 mm. The drift region reduces the gain

  2. Development, simulation and test of transition radiation detector prototypes for the compressed baryonic matter experiment at the facility for antiproton and ion research

    International Nuclear Information System (INIS)

    Bergmann, Cyrano S.H.

    2014-01-01

    The focus of this thesis is the development of a Transition Radiation Detector (TRD) for the Compressed Baryonic Matter (CBM) experiment at FAIR. The TRD sub-detector will contribute to the global particle identification and track reconstruction of charged particles. The technical design goal for the TRD is to identify 90% electrons with a maximum pion contamination of 1%. The TRD and Ring Image CHerenkov (RICH) detector should reach a common pion rejection of 10 4 , in order to measure charmonium and low-mass vector mesons. The position resolution should be between 200 and 300 μm in the anode wire direction. The most demanding aspect of the CBM TRD design is the high interaction rate of up to 10 7 Hz resulting in a charged particle rate of up to 100 kHz/cm 2 in the central part of the detector planes at SIS300 conditions. It is crucial to find the optimal radiator detector combination with a minimum material budget to limit scattering and background due to conversions and at the same time reach a sufficient pion rejection and position resolution. In this thesis it is confirmed that a Multi-Wire Proportional Counter (MWPC) with a Xe/CO 2 gas thickness of 12mm provides sufficient absorption probability for TR-photons in combination with self-supporting low density PE foam or micro-structured foil radiators. A continuous investigation aiming at an optimal wire and pad-plane geometry, as well as a minimization of the material budget between active gas and radiator has been presented in hard- and software. A minimum photon absorption cross-section of the entrance window was realized with a thermally stretched aluminized Kapton foil, glued to a G11 support grid support frame. This structure limits the mechanical deformation of the entire window to 1mm/mbar. All MWPC prototypes include two wire planes. A symmetric amplification region of 2 x (3, 3.5 or 4)mm is followed by a short drift region of 6, 5 or 4 mm. The drift region reduces the gain variation due to

  3. Thermal, intermediate and fast neutron flux measurements using activation detectors; Mesure des flux de neutrons thermiques, intermediaires et rapides au moyen de detecteurs par activation

    Energy Technology Data Exchange (ETDEWEB)

    Brisbois, J; Lott, M; Manent, G [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1964-07-01

    The problem of neutron flux measurements using activation detectors is studied in the particular case of protection research. It is shown how it possible, it is possible, using a known thermal flux, to organise a coherent calibration system for all the detectors. The rapid neutron detectors are calibrated with respect to a reference detector (phosphorus) in a natural uranium converter; the intermediate neutron detectors with respect to gold in the axial channel of ZOE. This method makes it possible to minimise the errors due to the activation cross-sections. A brief description is given of the counting room of the Pile Safety Study Service, as well of the practical utilisation characteristics of the counters employed. (authors) [French] Le probleme de la mesure des flux de neutrons au moyen de detecteurs par activation est etudie dans le cas particulier des etudes de protections. On montre comment, a partir d'un flux thermique connu, on peut organiser un systeme coherent d'etalonnage de tous les detecteurs. Les detecteurs de neutrons rapides sont etalonnes par rapport a un detecteur de reference (phosphore) dans un convertisseur en uranium naturel; les detecteurs de neutrons intermediaires, par rapport a l'or dans le canal axial de ZOE, Cette methode permet de minimiser les erreurs dues aux sections efficaces d'activation. On decrit sommairement la salle de comptage du Service d'Etudes de Protections de Piles et on indique les caracteristiques d'emploi pratique des detecteurs utilises. (auteurs)

  4. The Young-Feynman two-slits experiment with single electrons: Build-up of the interference pattern and arrival-time distribution using a fast-readout pixel detector

    Energy Technology Data Exchange (ETDEWEB)

    Frabboni, Stefano [Department of Physics, University of Modena and Reggio Emilia, Via G. Campi 213/a, 41125 Modena (Italy); CNR-Institute of Nanoscience-S3, Via G. Campi 213/a, 41125 Modena (Italy); Gabrielli, Alessandro [Department of Physics, University of Bologna, Viale B. Pichat 6/2, 40127 Bologna (Italy); INFN, Viale B. Pichat 6/2, 40127 Bologna (Italy); Carlo Gazzadi, Gian [CNR-Institute of Nanoscience-S3, Via G. Campi 213/a, 41125 Modena (Italy); Giorgi, Filippo [Department of Physics, University of Bologna, Viale B. Pichat 6/2, 40127 Bologna (Italy); INFN, Viale B. Pichat 6/2, 40127 Bologna (Italy); Matteucci, Giorgio [Department of Physics, University of Bologna, Viale B. Pichat 6/2, 40127 Bologna (Italy); Pozzi, Giulio, E-mail: giulio.pozzi@unibo.it [Department of Physics, University of Bologna, Viale B. Pichat 6/2, 40127 Bologna (Italy); Cesari, Nicola Semprini; Villa, Mauro; Zoccoli, Antonio [Department of Physics, University of Bologna, Viale B. Pichat 6/2, 40127 Bologna (Italy); INFN, Viale B. Pichat 6/2, 40127 Bologna (Italy)

    2012-05-15

    The two-slits experiment for single electrons has been carried out by inserting in a conventional transmission electron microscope a thick sample with two nano-slits fabricated by Focused Ion Beam technique and a fast recording system able to measure the electron arrival-time. The detector, designed for experiments in future colliders, is based on a custom CMOS chip equipped with a fast readout chain able to manage up to 10{sup 6} frames per second. In this way, high statistic samples of single electron events can be collected within a time interval short enough to measure the distribution of the electron arrival-times and to observe the build-up of the interference pattern. -- Highlights: Black-Right-Pointing-Pointer We present the first results obtained regarding the two-slits Young-Feynman experiment with single electrons. Black-Right-Pointing-Pointer We use two nano-slits fabricated by Focused Ion Beam technique. Black-Right-Pointing-Pointer We insert in the transmission electron microscope a detector, designed for experiments in future colliders. Black-Right-Pointing-Pointer We record the build-up of high statistic single electron interference patterns. Black-Right-Pointing-Pointer We measure the time distribution of electron arrivals.

  5. The LUCID-2 Detector

    CERN Document Server

    Sbarra, Carla; The ATLAS collaboration

    2018-01-01

    LUCID-2 (LUminosity Cherenkov Integrating Detector) is the upgrade of the main detector dedicated to luminosity measurements in ATLAS. Most changes were motivated by the number of interactions per bunch-crossing and the 25 ns bunch-spacing expected in LHC RUN II (2015-2018). Both fast online information used by LHC for luminosity optimisation and levelling in ATLAS, and per-bunch data to be used offline, come from LUCID-2

  6. Reduced Fokker-Planck models for fast particle distribution across a transition layer of disparate plasma temperatures

    Science.gov (United States)

    Tang, Xian-Zhu; Berk, H. L.; Guo, Zehua; McDevitt, C. J.

    2014-03-01

    Across a transition layer of disparate plasma temperatures, the high energy tail of the plasma distribution can have appreciable deviations from the local Maxwellian distribution due to the Knudson layer effect. The Fokker-Planck equation for the tail particle population can be simplified in a series of practically useful limiting cases. The first is the approximation of background Maxwellian distribution for linearizing the collision operator. The second is the supra-thermal particle speed ordering of vTi ≪ v ≪ vTe for the tail ions and vTi ≪ vTe ≪ v for the tail electrons. Keeping both the collisional drag and energy scattering is essential for the collision operator to produce a Maxwellian tail distribution. The Fokker-Planck model for following the tail ion distribution for a given background plasma profile is explicitly worked out for systems of one spatial dimension, in both slab and spherical geometry. A third simplification is an expansion of the tail particle distribution using the spherical harmonics, which are eigenfunctions of the pitch angle scattering operator. This produces a set of coupled Fokker-Planck equations that contain energy-dependent spatial diffusion terms in two coordinates (position and energy), which originate from pitch angle scattering in the original Fokker-Planck equation. It is shown that the well-known diffusive Fokker-Planck model is a poor approximation of the two-mode truncation model, which itself has fundamental deficiency compared with the three-mode truncation model. The cause is the lack of even-symmetry representation in pitch dependence in the two-mode truncation model.

  7. Invited article: The fast readout low noise camera as a versatile x-ray detector for time resolved dispersive extended x-ray absorption fine structure and diffraction studies of dynamic problems in materials science, chemistry, and catalysis

    International Nuclear Information System (INIS)

    Labiche, Jean-Claude; Mathon, Olivier; Pascarelli, Sakura; Newton, Mark A.; Ferre, Gemma Guilera; Curfs, Caroline; Vaughan, Gavin; Homs, Alejandro; Carreiras, David Fernandez

    2007-01-01

    Originally conceived and developed at the European Synchrotron Radiation Facility (ESRF) as an 'area' detector for rapid x-ray imaging studies, the fast readout low noise (FReLoN) detector of the ESRF [J.-C. Labiche, ESRF Newsletter 25, 41 (1996)] has been demonstrated to be a highly versatile and unique detector. Charge coupled device (CCD) cameras at present available on the public market offer either a high dynamic range or a high readout speed. A compromise between signal dynamic range and readout speed is always sought. The parameters of the commercial cameras can sometimes be tuned, in order to better fulfill the needs of specific experiments, but in general these cameras have a poor duty cycle (i.e., the signal integration time is much smaller than the readout time). In order to address scientific problems such as time resolved experiments at the ESRF, a FReLoN camera has been developed by the Instrument Support Group at ESRF. This camera is a low noise CCD camera that combines high dynamic range, high readout speed, accuracy, and improved duty cycle in a single image. In this paper, we show its application in a quasi-one-dimensional sense to dynamic problems in materials science, catalysis, and chemistry that require data acquisition on a time scale of milliseconds or a few tens of milliseconds. It is demonstrated that in this mode the FReLoN can be applied equally to the investigation of rapid changes in long range order (via diffraction) and local order (via energy dispersive extended x-ray absorption fine structure) and in situations of x-ray hardness and flux beyond the capacity of other detectors

  8. Digital readouts for large microwave low-temperature detector arrays

    International Nuclear Information System (INIS)

    Mazin, Benjamin A.; Day, Peter K.; Irwin, Kent D.; Reintsema, Carl D.; Zmuidzinas, Jonas

    2006-01-01

    Over the last several years many different types of low-temperature detectors (LTDs) have been developed that use a microwave resonant circuit as part of their readout. These devices include microwave kinetic inductance detectors (MKID), microwave SQUID readouts for transition edge sensors (TES), and NIS bolometers. Current readout techniques for these devices use analog frequency synthesizers and IQ mixers. While these components are available as microwave integrated circuits, one set is required for each resonator. We are exploring a new readout technique for this class of detectors based on a commercial-off-the-shelf technology called software defined radio (SDR). In this method a fast digital to analog (D/A) converter creates as many tones as desired in the available bandwidth. Our prototype system employs a 100MS/s 16-bit D/A to generate an arbitrary number of tones in 50MHz of bandwidth. This signal is then mixed up to the desired detector resonant frequency (∼10GHz), sent through the detector, then mixed back down to baseband. The baseband signal is then digitized with a series of fast analog to digital converters (80MS/s, 14-bit). Next, a numerical mixer in a dedicated integrated circuit or FPGA mixes the resonant frequency of a specified detector to 0Hz, and sends the complex detector output over a computer bus for processing and storage. In this paper we will report on our results in using a prototype system to readout a MKID array, including system noise performance, X-ray pulse response, and cross-talk measurements. We will also discuss how this technique can be scaled to read out many thousands of detectors

  9. 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)

  10. Transition metal redox switches for reversible "on/off" and "slow/fast" single-molecule magnet behaviour in dysprosium and erbium bis-diamidoferrocene complexes.

    Science.gov (United States)

    Dickie, Courtney M; Laughlin, Alexander L; Wofford, Joshua D; Bhuvanesh, Nattamai S; Nippe, Michael

    2017-12-01

    Single-molecule magnets (SMMs) are considered viable candidates for next-generation data storage and quantum computing. Systems featuring switchability of their magnetization dynamics are particularly interesting with respect to accessing more complex logic gates and device architectures. Here we show that transition metal based redox events can be exploited to enable reversible switchability of slow magnetic relaxation of magnetically anisotropic lanthanide ions. Specifically, we report anionic homoleptic bis-diamidoferrocene complexes of Dy 3+ (oblate) and Er 3+ (prolate) which can be reversibly oxidized by one electron to yield their respective charge neutral redox partners (Dy: [1] - , 1 ; Er: [2] - , 2 ). Importantly, compounds 1 and 2 are thermally stable which allowed for detailed studies of their magnetization dynamics. We show that the Dy 3+ [1] - / 1 system can function as an "on"/"off" or a "slow"/"fast" redox switchable SMM system in the absence or presence of applied dc fields, respectively. The Er 3+ based [2] - / 2 system features "on"/"off" switchability of SMM properties in the presence of applied fields. Results from electrochemical investigations, UV-vis-NIR spectroscopy, and 57 Fe Mössbauer spectroscopy indicate the presence of significant electronic communication between the mixed-valent Fe ions in 1 and 2 in both solution and solid state. This comparative evaluation of redox-switchable magnetization dynamics in low coordinate lanthanide complexes may be used as a potential blueprint toward the development of future switchable magnetic materials.

  11. Experimental study of core thermohydraulics in fast reactors during transition from forced to natural circulation. Influence of inter-wrapper flow

    International Nuclear Information System (INIS)

    Kamide, H.; Hayashi, K.; Momoi, K.

    1997-01-01

    The evaluation of core thermohydraulics under natural circulation conditions is important to utilize inherent safety features of Fast Reactors. When heat exchangers of a decay heat removal system are operated in an upper plenum of reactor vessel, cold sodium is provided by the heat exchangers. Core-plenum interactions will occur during a natural circulation condition due to this cold sodium in the upper plenum, e.g., it can penetrate into gap regions between fuel subassemblies (inter-wrapper flow, IWF) and the flow may reverse in low power core channels. These interactions will significantly modify the flow and temperature distributions in the core. Sodium experiments were carried out to study these phenomena. In a test section, seven subassemblies are housed and connected to an upper plenum. The influences of core-plenum interactions on the core thermohydraulics were investigated under steady state conditions and also in transitions from forced to natural circulation. Cooling effects of IWF on the fuel subassemblies were found in spite of natural circulation flow reduction in the primary loop due to temperature decreases in the upper non-heated section in the core. The inter-wrapper flow can effectively cool the core under extreme conditions of low flow rates through the core. (author)

  12. 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.)

  13. Radiation damage in semiconductor detectors

    International Nuclear Information System (INIS)

    Kraner, H.W.

    1981-12-01

    A survey is presented of the important damage-producing interactions in semiconductor detectors and estimates of defect numbers are made for MeV protons, neutrons and electrons. Damage effects of fast neutrons in germanium gamma ray spectrometers are given in some detail. General effects in silicon detectors are discussed and damage constants and their relationship to leakage current is introduced

  14. Development of a Large Area Advanced Fast RICH Detector for Particle Identification at the Large Hadron Collider Operated with Heavy Ions

    CERN Multimedia

    Piuz, F; Braem, A; Van beelen, J B; Lion, G; Gandi, A

    2002-01-01

    %RD26 %title\\\\ \\\\During the past two years, RD26 groups have focused their activities on the production of CsI-RICH prototypes of large area, up to a square meter, to demonstrate their application in High Energy experiments. Many large CsI-photocathodes (up to 40) were produced following the processing techniques furthermore developped in the collaboration. Taking the Quantum Efficiency (QE) measured at 180 nm as a comparative figure of merit of a CsI-PC. Figure 1 shows the increase of the performance while improvements were successively implemented in the PC processing sequence. Most efficient were the use of substrates made of nickel, the heat treatment and handling of the PCs under inert gas. Actually, three large systems based on CsI-RICH have got approval in the following HEP experiments: HADES at GSI, COMPASS/NA58 at CERN and HMPID/ALICE at LHC implying up to 14 square metres of CsI-PC. In addition, several CsI-RICH detectors have been successfully operated in the Threshold Imaging Detector at NA44 and ...

  15. arXiv Test beam measurement of the first prototype of the fast silicon pixel monolithic detector for the TT-PET project

    CERN Document Server

    Paolozzi, L.; Benoit, M.; Cardarelli, R.; Débieux, S.; Forshaw, D.; Hayakawa, D.; Iacobucci, G.; Kaynak, M.; Miucci, A.; Nessi, M.; Ratib, O.; Ripiccini, E.; Rücker, H.; Valerio, P.; Weber, M.

    2018-04-12

    The TT-PET collaboration is developing a PET scanner for small animals with  30 ps  time-of-flight resolution and sub-millimetre 3D detection granularity. The sensitive element of the scanner is a monolithic silicon pixel detector based on state-of-the-art SiGe BiCMOS technology. The first ASIC prototype for the TT-PET was produced and tested in the laboratory and with minimum ionizing particles. The electronics exhibit an equivalent noise charge below  600 e− RMS  and a pulse rise time of less than  2 ns , in accordance with the simulations. The pixels with a capacitance of  0.8 pF  were measured to have a detection efficiency greater than  99%  and, although in the absence of the post-processing, a time resolution of approximately  200 ps .

  16. Fast flux measurements by means of threshold detectors on the reactor 'Melusine'; Mesures de flux rapides a l'aide de detecteurs a seuil sur le reacteur 'Melusine'

    Energy Technology Data Exchange (ETDEWEB)

    Leger, P; Sautiez, B [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1959-07-01

    Using existing data on the (n,p) and (n,{alpha}) threshold reactions we have carried out fast flux measurements on the swimming pool type reactor 'Melusine'. Four common elements: P, S, Mg, Al were chosen because from the point of view of fast spectrum analysis they represent a fairly good energy range from 2.4 MeV to 8 MeV. The fission flux value found in the central element at a power of 1 MW is 1.4 x 10{sup 13} n/cm{sup 2}/s {+-} 0.14. (author) [French] A l'aide des donnees actuelles sur les reactions a seuil (n,p) et (n,{alpha}) nous avons realise des mesures de flux rapide dans le reacteur du type piscine 'Melusine'. Quatre corps courants: P, S, Mg, Al, ont ete choisis parce qu'ils constituent au point de vue de l'analyse du spectre rapide un assez bon etalement en energie de 2,4 MeV A 8 MeV. La valeur du flux de fission trouve dans l'element central a une puissance de 1 MW est de 1,4.10{sup 13} n/cm{sup 2}/s {+-} 0,14. (auteur)

  17. The STAR Vertex Position Detector

    Energy Technology Data Exchange (ETDEWEB)

    Llope, W.J., E-mail: llope@rice.edu [Rice University, Houston, TX 77005 (United States); Zhou, J.; Nussbaum, T. [Rice University, Houston, TX 77005 (United States); Hoffmann, G.W. [University of Texas, Austin, TX 78712 (United States); Asselta, K. [Brookhaven National Laboratory, Upton, NY 11973 (United States); Brandenburg, J.D.; Butterworth, J. [Rice University, Houston, TX 77005 (United States); Camarda, T.; Christie, W. [Brookhaven National Laboratory, Upton, NY 11973 (United States); Crawford, H.J. [University of California, Berkeley, CA 94720 (United States); Dong, X. [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Engelage, J. [University of California, Berkeley, CA 94720 (United States); Eppley, G.; Geurts, F. [Rice University, Houston, TX 77005 (United States); Hammond, J. [Brookhaven National Laboratory, Upton, NY 11973 (United States); Judd, E. [University of California, Berkeley, CA 94720 (United States); McDonald, D.L. [Rice University, Houston, TX 77005 (United States); Perkins, C. [University of California, Berkeley, CA 94720 (United States); Ruan, L.; Scheblein, J. [Brookhaven National Laboratory, Upton, NY 11973 (United States); and others

    2014-09-21

    The 2×3 channel pseudo Vertex Position Detector (pVPD) in the STAR experiment at RHIC has been upgraded to a 2×19 channel detector in the same acceptance, called the Vertex Position Detector (VPD). This detector is fully integrated into the STAR trigger system and provides the primary input to the minimum-bias trigger in Au+Au collisions. The information from the detector is used both in the STAR Level-0 trigger and offline to measure the location of the primary collision vertex along the beam pipe and the event “start time” needed by other fast-timing detectors in STAR. The offline timing resolution of single detector channels in full-energy Au+Au collisions is ∼100 ps, resulting in a start time resolution of a few tens of picoseconds and a resolution on the primary vertex location of ∼1 cm.

  18. 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

  19. Influence of sampling properties of fast-waveform digitizers on neutron−gamma-ray, pulse-shape discrimination for organic scintillation detectors

    International Nuclear Information System (INIS)

    Flaska, Marek; Faisal, Muhammad; Wentzloff, David D.; Pozzi, Sara A.

    2013-01-01

    One of the most important questions to be answered with regard to digital pulse-shape discrimination (PSD) systems based on organic scintillators is: What sampling properties are required for a fast-waveform digitizer used for digitizing neutron/gamma-ray pulses, while an accurate PSD is desired? Answering this question is the main objective of this paper. Specifically, the paper describes the influence of the resolution and sampling frequency of a waveform digitizer on the PSD performance of organic scintillators. The results presented in this paper are meant to help the reader choosing a waveform digitizer with appropriate bit resolution and sampling frequency. The results presented here show that a 12-bit, 250-MHz digitizer is a good choice for applications that require good PSD performance. However, when more accurate PSD performance is the main requirement, this paper presents PSD figures of merit to qualify the impact of further increasing either sampling frequency or resolution of the digitizer

  20. Measurements of Ultra-Fast single photon counting chip with energy window and 75 μm pixel pitch with Si and CdTe detectors

    International Nuclear Information System (INIS)

    Maj, P.; Grybos, P.; Kasinski, K.; Koziol, A.; Krzyzanowska, A.; Kmon, P.; Szczygiel, R.; Zoladz, M.

    2017-01-01

    Single photon counting pixel detectors become increasingly popular in various 2-D X-ray imaging techniques and scientific experiments mainly in solid state physics, material science and medicine. This paper presents architecture and measurement results of the UFXC32k chip designed in a CMOS 130 nm process. The chip consists of about 50 million transistors and has an area of 9.64 mm × 20.15 mm. The core of the IC is a matrix of 128 × 256 pixels of 75 μm pitch. Each pixel contains a CSA, a shaper with tunable gain, two discriminators with correction circuits and two 14-bit ripple counters operating in a normal mode (with energy window), a long counter mode (one 28-bit counter) and a zero-dead time mode. Gain and noise performance were verified with X-ray radiation and with the chip connected to Si (320 μm thick) and CdTe (750 μ m thick) sensors.

  1. 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.

  2. 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.

  3. Silicon Pixel Detectors for Synchrotron Applications

    CERN Document Server

    Stewart, Graeme Douglas

    Recent advances in particle accelerators have increased the demands being placed on detectors. Novel detector designs are being implemented in many different areas including, for example, high luminosity experiments at the LHC or at next generation synchrotrons. The purpose of this thesis was to characterise some of these novel detectors. The first of the new detector types is called a 3D detector. This design was first proposed by Parker, Kenney and Segal (1997). In this design, doped electrodes are created that extend through the silicon substrate. When compared to a traditional photodiode with electrodes on the opposing surfaces, the 3D design can combine a reasonable detector thickness with a small electrode spacing resulting in fast charge collection and limited charge sharing. The small electrode spacing leads to the detectors having lower depletion voltages. This, combined with the fast collection time, makes 3D detectors a candidate for radiation hard applications. These applications include the upgra...

  4. ATLAS muon detector

    CERN Multimedia

    Muon detectors from the outer layer of the ATLAS experiment at the Large Hadron Collider. Over a million individual detectors combine to make up the outer layer of ATLAS. All of this is exclusively to track the muons, the only detectable particles to make it out so far from the collision point. How the muon’s path curves in the magnetic field depends on how fast it is travelling. A fast muon curves only a very little, a slower one curves a lot. Together with the calorimeters, the muon detectors play an essential role in deciding which collisions to store and which to ignore. Certain signals from muons are a sure sign of exciting discoveries. To make sure the data from these collisions is not lost, some of the muon detectors react very quickly and trigger the electronics to record. The other detectors take a little longer, but are much more precise. Their job is to measure exactly where the muons have passed, calculating the curvature of their tracks in the magnetic field to the nearest five hundredths of a ...

  5. Systematic chemical profiling of Citrus grandis 'Tomentosa' by ultra-fast liquid chromatography/diode-array detector/quadrupole time-of-flight tandem mass spectrometry.

    Science.gov (United States)

    Li, Pan-lin; Liu, Meng-hua; Hu, Jie-hui; Su, Wei-wei

    2014-03-01

    Citrus grandis 'Tomentosa', as the original plant of the traditional Chinese medicine "Huajuhong", has been used as antitussive and expectorant in clinic for thousands of years. The fruit epicarp and whole fruit of this plant were both literarily recorded and commonly used. In the present study, an ultra-fast liquid chromatography coupled with diode-array detection and quadrupole/time-of-flight mass spectrometry (UFLC-DAD-Q-TOF-MS/MS) based chemical profiling method was developed for rapid holistic quality evaluation of C. grandis 'Tomentosa', which laid basis for chemical comparison of two medicinal parts. As a result, forty-eight constituents, mainly belonging to flavonoids and coumarins, were unambiguously identified by comparison with reference standards and/or tentatively characterized by elucidating UV spectra, quasi-molecular ions and fragment ions referring to information available in literature. Both of the epicarp and whole fruit samples were rich in flavonoids and coumarins, but major flavonoids contents in whole fruit were significantly higher than in epicarp (P<0.5). The proposed method could be useful in quality control and standardization of C. grandis 'Tomentosa' raw materials and its products. Results obtained in this study will provide a basis for quality assessment and further study in vivo. Copyright © 2013 Elsevier B.V. All rights reserved.

  6. Semiconductor detectors in nuclear and particle physics

    International Nuclear Information System (INIS)

    Rehak, P.; Gatti, E.

    1992-01-01

    Semiconductor detectors for elementary particle physics and nuclear physics in the energy range above 1 GeV are briefly reviewed. In these two fields semiconductor detectors are used mainly for the precise position sensing. In a typical experiment, the position of a fast charged particle crossing a relatively thin semiconductor detector is measured. The position resolution achievable by semiconductor detectors is compared with the resolution achievable by gas filled position sensing detectors. Semiconductor detectors are divided into two groups: Classical semiconductor diode detectors and semiconductor memory detectors. Principles of the signal formation and the signal read-out for both groups of detectors are described. New developments of silicon detectors of both groups are reported

  7. Semiconductor detectors in nuclear and particle physics

    International Nuclear Information System (INIS)

    Rehak, P.; Gatti, E.

    1995-01-01

    Semiconductor detectors for elementary particle physics and nuclear physics in the energy range above 1 GeV are briefly reviewed. In these two fields semiconductor detectors are used mainly for the precise position sensing. In a typical experiment, the position of a fast charged particle crossing a relatively thin semiconductor detector is measured. The position resolution achievable by semiconductor detectors is compared with the resolution achievable by gas filled position sensing detectors. Semiconductor detectors are divided into two groups; (i) classical semiconductor diode detectors and (ii) semiconductor memory detectors. Principles of the signal formation and the signal read-out for both groups of detectors are described. New developments of silicon detectors of both groups are reported. copyright 1995 American Institute of Physics

  8. Detectors for Tomorrow's Instruments

    Science.gov (United States)

    Moseley, Harvey

    2009-01-01

    Cryogenically cooled superconducting detectors have become essential tools for a wide range of measurement applications, ranging from quantum limited heterodyne detection in the millimeter range to direct searches for dark matter with superconducting phonon detectors operating at 20 mK. Superconducting detectors have several fundamental and practical advantages which have resulted in their rapid adoption by experimenters. Their excellent performance arises in part from reductions in noise resulting from their low operating temperatures, but unique superconducting properties provide a wide range of mechanisms for detection. For example, the steep dependence of resistance with temperature on the superconductor/normal transition provides a sensitive thermometer for calorimetric and bolometric applications. Parametric changes in the properties of superconducting resonators provides a mechanism for high sensitivity detection of submillimeter photons. From a practical point of view, the use of superconducting detectors has grown rapidly because many of these devices couple well to SQUID amplifiers, which are easily integrated with the detectors. These SQUID-based amplifiers and multiplexers have matured with the detectors; they are convenient to use, and have excellent noise performance. The first generation of fully integrated large scale superconducting detection systems are now being deployed. I will discuss the prospects for a new generation of instruments designed to take full advantage of the revolution in detector technology.

  9. 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

  10. The LUCID-2 Detector

    CERN Document Server

    Sbarra, Carla; The ATLAS collaboration

    2018-01-01

    LUCID-2 (LUminosity Cherenkov Integrating Detector) is the upgrade of the main detector dedicated to luminosity monitoring and measurements in the ATLAS Experiment at CERN. Most changes were motivated by the large (up to 50) number of interactions per bunch-crossing and short (25 ns) bunch-spacing expected in LHC run 2 (2015-2018). Both fast online information used by LHC for luminosity optimisation and levelling in ATLAS, and per-bunch data to be used offline, come from LUCID-2.

  11. The Fast Simulation Chain for ATLAS

    CERN Document Server

    Basalaev, Artem; The ATLAS collaboration

    2016-01-01

    In order to generate the huge number of Monte Carlo events that will be required by the ATLAS experiment over the next several runs, a very fast simulation is critical. Fast detector simulation alone, however, is insufficient: with very high numbers of simultaneous proton-proton collisions expected in Run 3 and beyond, the digitization (detector response emulation) and event reconstruction time quickly become comparable to the time required for detector simulation. The ATLAS Fast Chain simulation has been developed to solve this problem. Modules are implemented for fast simulation, fast digitization, and fast track reconstruction. The application is sufficiently fast -- several orders of magnitude faster than the standard simulation -- that the simultaneous proton-proton collisions can be generated during the simulation job, so Pythia8 also runs concurrently with the rest of the algorithms. The Fast Chain has been built to be extremely modular and flexible, so that each sample can be custom-tailored to match ...

  12. 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.

  13. 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.

  14. Detector trends

    International Nuclear Information System (INIS)

    Charpak, G.

    1986-01-01

    The author describes briefly the development of detectors for high energy physics experiments. Especially considered are semiconductor microstrip detectors, drift tubes, holographic bubble chambers, scintillating fiber optics, and calorimeters. (HSI).

  15. Infrared detectors

    CERN Document Server

    Rogalski, Antonio

    2010-01-01

    This second edition is fully revised and reorganized, with new chapters concerning third generation and quantum dot detectors, THz detectors, cantilever and antenna coupled detectors, and information on radiometry and IR optics materials. Part IV concerning focal plane arrays is significantly expanded. This book, resembling an encyclopedia of IR detectors, is well illustrated and contains many original references … a really comprehensive book.-F. Sizov, Institute of Semiconductor Physics, National Academy of Sciences, Kiev, Ukraine

  16. Studies on the target detector of the LAND experiment

    International Nuclear Information System (INIS)

    Zinser, M.

    1991-09-01

    In the framework of this diploma thesis the target detector of the LAND experiment was for the first time taken into operation. The target detector consists of 48 BaF 2 crystals and 36 plastic scintillators. The BaF 2 detectors shall be mainly applied to the measurements of Γ quanta from giant resonance excitations and transitions in exotic nuclei. The plastic scintillators serve for the determination of the multiplicity of the charged particles emitted in a reaction. The electronics of the target detector were for the first experiment of the LAND collaboration on the electromagnetic excitation in peripheral heavy ion reactions at near-relativistic energies together constructed and tested. In the following for the BaF 2 crystals calibration measurements with two γ sources and for the plastic scintillators with a β preparate were performed. The evaluation of the measurements was performed on a VAX station of the Mainz University, on which a by the LAND collaboration modified version of the analysis program PAW was installed. The analysis of the plastic scintillators yields a bad energy resolution of at least 0.6. For the BaF 2 detectors PAW was extended by a comand, which allows a semi-automatic performation of the calibration. The results obtained by this procedure are consistent with calibrations, which were performed independently on this in the collaboration. By the new routine it is possible to perform the energy calibration of the BaF 2 crystals fastly and efficiently. The resolution of the BaF 2 detectors lies around 10%. By this experiments on the giant-resonance excitation and first studies on γ transitions with exotic nuclei are performable. (orig./HSI) [de

  17. GANIL beam profile detectors

    International Nuclear Information System (INIS)

    Tribouillard, C.

    1997-01-01

    In the design phase of GANIL which started in 1977, one of the priorities of the project management was equipping the beamlines with a fast and efficient system for visualizing the beam position, thus making possible adjustment of the beam transport lines optics and facilitating beam control. The implantation of some thirty detectors was foreseen in the initial design. The assembly of installed detectors (around 190) proves the advantages of these detectors for displaying all the beams extracted from GANIL: transfer and transport lines, beam extracted from SISSI, very high intensity beam, secondary ion beams from the production target of the LISE and SPEG spectrometers, different SPIRAL project lines. All of these detectors are based on standard characteristics: - standard flange diameter (DN 160) with a standard booster for all the sensors; - identical analog electronics for all the detectors, with networking; - unique display system. The new micro-channel plate non-interceptive detectors (beam profile and ion packet lengths) make possible in-line control of the beam quality and accelerator stability. (author)

  18. Detector performance tests for the CBM TRD

    Energy Technology Data Exchange (ETDEWEB)

    Kohn, Martin [Institut fuer Kernphysik, WWU Muenster (Germany)

    2016-07-01

    The Compressed Baryonic Matter (CBM) experiment is a fixed target heavy-ion experiment at the future FAIR accelerator facility. The CBM Transition Radiation Detector (TRD) is one of the key detectors to provide electron identification and charged particle tracking. With the construction phase of the detector nearing, we will present results of the detector obtained with a close to final prototype. These results were achieved in measurements at CERN PS in 2014 and SPS in 2015.

  19. Particlc detectors. Foundations and applications; Teilchendetektoren. Grundlagen und Anwendungen

    Energy Technology Data Exchange (ETDEWEB)

    Kolanoski, Hermann; Wermes, Norbert

    2016-08-01

    The following topics are dealt with: Interaction of particles with matter, motion of charge carriers in electric and magnetic fields, signal generation by moving charges, non-electronic detectors, gas-filled detectors, semiconductor detectors, track reconstruction and momentum measurement, photodetectors, Cherenkov detectors, transition-radiation detectors, scintillation detectors, particle identification, calorimeters, detection of cosmic particles, signal processing and noise, trigger and data acquisition systems. (HSI)

  20. The Fast Simulation Chain for ATLAS

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00399337; The ATLAS collaboration; Marshall, Zach

    2017-01-01

    In order to generate the huge number of Monte Carlo events that will be required by the ATLAS experiment over the next several runs, a very fast simulation is critical. Fast detector simulation alone, however, is insufficient: with very high numbers of simultaneous proton-proton collisions expected in Run 3 and beyond, the digitization (detector response emulation) and event reconstruction time quickly become comparable to the time required for detector simulation. The ATLAS Fast Chain simulation has been developed to solve this problem. Modules are implemented for fast simulation, fast digitization, and fast track reconstruction. The application is sufficiently fast—several orders of magnitude faster than the standard simulation—that the simultaneous proton-proton collisions can be generated during the simulation job, so Pythia8 also runs concurrently with the rest of the algorithms. The Fast Chain has been built to be extremely modular and flexible, so that each sample can be custom-tailored to match th...

  1. Analysis of Russian transition scenarios to innovative nuclear energy system based on thermal and fast reactors with closed nuclear fuel cycle using INPRO methodology

    International Nuclear Information System (INIS)

    Kagramanyan, V.S.; Poplavskaya, E.V.; Korobeynikov, V.V.; Kalashnikov, A.G.; Moseev, A.L.; Korobitsyn, V.E.; Andreeva-Andrievskaya, L.N.

    2011-01-01

    This paper presents the results of the analysis of modeling of Russian nuclear energy (NE) scenarios on the basis of thermal and fast reactors with closed nuclear fuel cycle (NFC). Modeling has been carried out with use of CYCLE code (SSC RF IPPE's tool) designed for analysis of Nuclear Energy System (NES) with closed NFC taking into account plutonium and minor actinides (MA) isotopic composition change during multi-recycling of fuel in fast reactors. When considering fast reactor introduction scenarios, one of important questions is to define optimal time for their introduction and related NFC's facilities. Analysis of the results obtained has been fulfilled using the key INPRO indicators for sustainable energy development. It was shown that a delay in fast reactor introduction led to serious ecological, social and finally economic risks for providing energy security and sustainable development of Russia in long-term prospects and loss of knowledge and experience in mastering innovative technologies of fast reactors and related nuclear fuel cycle. (author)

  2. Acquisition System and Detector Interface for Power Pulsed Detectors

    CERN Document Server

    Cornat, R

    2012-01-01

    A common DAQ system is being developed within the CALICE collaboration. It provides a flexible and scalable architecture based on giga-ethernet and 8b/10b serial links in order to transmit either slow control data, fast signals or read out data. A detector interface (DIF) is used to connect detectors to the DAQ system based on a single firmware shared among the collaboration but targeted on various physical implementations. The DIF allows to build, store and queue packets of data as well as to control the detectors providing USB and serial link connectivity. The overall architecture is foreseen to manage several hundreds of thousands channels.

  3. Innovative mid-infrared detector concepts

    Science.gov (United States)

    Höfling, Sven; Pfenning, Andreas; Weih, Robert; Ratajczak, Albert; Hartmann, Fabian; Knebl, Georg; Kamp, Martin; Worschech, Lukas

    2016-09-01

    Gas sensing is a key technology with applications in various industrial, medical and environmental areas. Optical detection mechanisms allow for a highly selective, contactless and fast detection. For this purpose, rotational-vibrational absorption bands within the mid infrared (MIR) spectral region are exploited and probed with appropriate light sources. During the past years, the development of novel laser concepts such as interband cascade lasers (ICLs) and quantum cascade lasers (QCLs) has driven a continuous optimization of MIR laser sources. On the other hand side, there has been relatively little progress on detectors in this wavelength range. Here, we study two novel and promising GaSb-based detector concepts: Interband cascade detectors (ICD) and resonant tunneling diode (RTD) photodetectors. ICDs are a promising approach towards highly sensitive room temperature detection of MIR radiation. They make use of the cascading scheme that is enabled by the broken gap alignment of the two binaries GaSb and InAs. The interband transition in GaSb/InAs-superlattices (SL) allows for normal incidence detection. The cut-off wavelength, which determines the low energy detection limit, can be engineered via the SL period. RTD photodetectors act as low noise and high speed amplifiers of small optically generated electrical signals. In contrast to avalanche photodiodes, where the gain originates from multiplication due to impact ionization, in RTD photodetectors a large tunneling current is modulated via Coulomb interaction by the presence of photogenerated minority charge carriers. For both detector concepts, first devices operational at room temperature have been realized.

  4. The ATLAS Inner Detector

    CERN Document Server

    Gray, HM; The ATLAS collaboration

    2012-01-01

    The ATLAS experiment at the LHC is equipped with a charged particle tracking system, the Inner Detector, built on three subdetectors, which provide high precision measurements made from a fine detector granularity. The Pixel and microstrip (SCT) subdetectors, which use the silicon technology, are complemented with the Transition Radiation Tracker. Since the LHC startup in 2009, the ATLAS inner tracker has played a central role in many ATLAS physics analyses. Rapid improvements in the calibration and alignment of the detector allowed it to reach nearly the nominal performance in the timespan of a few months. The tracking performance proved to be stable as the LHC luminosity increased by five orders of magnitude during the 2010 proton run, New developments in the offline reconstruction for the 2011 run will improve the tracking performance in high pile-up conditions as well as in highly boosted jets will be discussed.

  5. Status of diamond particle detectors

    Science.gov (United States)

    Krammer, M.; Adam, W.; Bauer, C.; Berdermann, E.; Bogani, F.; Borchi, E.; Bruzzi, M.; Colledani, C.; Conway, J.; Dabrowski, W.; Delpierre, P.; Deneuville, A.; Dulinski, W.; van Eijk, B.; Fallou, A.; Fish, D.; Foulon, F.; Friedl, M.; 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.; Kass, R.; Knöpfle, K. T.; Manfredi, P. F.; Meier, D.; Mishina, M.; LeNormand, F.; Pan, L. S.; Pernegger, H.; Pernicka, M.; Re, V.; Riester, G. 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.; Turchetta, R.; Walsh, A. M.; Wedenig, R.; Weilhammer, P.; Ziock, H.; Zoeller, M.

    1998-11-01

    To continue the exciting research in the field of particle physics new accelerators and experiments are under construction. In some of these experiments, e.g. ATLAS and CMS at the Large Hadron Collider at CERN or HERA-B at DESY, the detectors have to withstand an extreme environment. The detectors must be radiation hard, provide a very fast signal, and be as thin as possible. The properties of CVD diamond allow to fulfill these requirements and make it an ideal material for the detectors close to the interaction region of these experiments, i.e. the vertex detectors or the inner trackers. The RD42 collaboration is developing diamond detectors for these applications. The program of RD42 includes the improvement of the charge collection properties of CVD diamond, the study of the radiation hardness and the development of low-noise radiation hard readout electronics. An overview of the progress achieved during the last years will be given.

  6. PHENIX Fast TOF

    Energy Technology Data Exchange (ETDEWEB)

    Soha, Aria [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Chiu, Mickey [Brookhaven National Lab. (BNL), Upton, NY (United States); Mannel, Eric [Brookhaven National Lab. (BNL), Upton, NY (United States); Stoll, Sean [Brookhaven National Lab. (BNL), Upton, NY (United States); Lynch, Don [Brookhaven National Lab. (BNL), Upton, NY (United States); Boose, Steve [Brookhaven National Lab. (BNL), Upton, NY (United States); Northacker, Dave [Brookhaven National Lab. (BNL), Upton, NY (United States); Alfred, Marcus [Howard Univ., Washington, DC (United States); Lindesay, James [Howard Univ., Washington, DC (United States); Chujo, Tatsuya [Univ. of Tsukuba (Japan); Inaba, Motoi [Univ. of Tsukuba (Japan); Nonaka, Toshihiro [Univ. of Tsukuba (Japan); Sato, Wataru [Univ. of Tsukuba (Japan); Sakatani, Ikumi [Univ. of Tsukuba (Japan); Hirano, Masahiro [Univ. of Tsukuba (Japan); Choi, Ihnjea [Univ. of Illinois, Urbana-Champaign, IL (United States)

    2014-01-15

    This is a technical scope of work (TSW) between the Fermi National Accelerator Laboratory (Fermilab) and the experimenters of PHENIX Fast TOF group who have committed to participate in beam tests to be carried out during the FY2014 Fermilab Test Beam Facility program. The goals for this test beam experiment are to verify the timing performance of the two types of time-of-flight detector prototypes.

  7. Fast diamond photoconductors

    International Nuclear Information System (INIS)

    Pochet, T.

    1993-01-01

    Preliminary results on the response of type Ib and IIa diamond photodetectors to fast laser pulse exposures at 265 and 530 nm are presented. The influence of the applied bias, the laser wavelengths and the light intensity on the detector sensitivity is studied. Also, recent measurements with 1.25 MeV gamma ray pulses are reported. (authors). 13 refs., 7 figs., 1 tab

  8. Phonon-mediated distributed transition-edge-sensor X-ray detectors for surveys of galaxy clusters and the warm-hot interstellar medium

    International Nuclear Information System (INIS)

    Leman, Steven W.; Brink, Paul L.; Cabrera, Blas; Castle, Joseph P.; Chakraborty, Sudeepto; Deiker, Steve; Kahn, Steve; Martinez-Galarce, Dennis S.; Stern, Robert A.; Tomada, Astrid

    2006-01-01

    We are developing a novel phonon-mediated distributed-TES X-ray detector in which X-rays are absorbed in a large germanium or silicon crystal, and the energy is read out by four distributed TESs. This design takes advantage of existing TES technology while overcoming the difficulties of designing spatially large arrays. The sum of the four TES signals will yield energy resolution of E/δE∼1000 and the partitioning of energy between the four will yield position resolution of X/δX and Y/δY∼100. These macropixels, with advances in multiplexing, could be close-packed into 30x30 arrays equivalent to imaging instruments of 10 megapixels or more. We report on our progress to date and discuss its application to galaxy cluster searches and studies of the Warm-Hot Interstellar Medium

  9. Development of severe accident evaluation technology (level 2 PSA) for sodium-cooled fast reactors. (3) Identification of dominant factors in transition phase of unprotected events

    International Nuclear Information System (INIS)

    Tobita, Yoshiharu; Yamano, Hidemasa; Sato, Ikken

    2009-01-01

    The event progression of the transition phase in the unprotected loss of flow accident of the JSFR design concept was analyzed using the SIMMER-III code reflecting the knowledge obtained from the EAGLE experimental program. It was clarified through the parametric calculations that the fuel discharge behavior through the paths such as the inner duct of modified-FAIDUS and control-rod guide tube is playing a very important role. Effective fuel discharge through these paths prevents possibility of severe recriticality events. Important factors dominating the transition phase were identified through these parametric calculations. (author)

  10. The fast slow TDPAC spectrometer

    International Nuclear Information System (INIS)

    Cekic, B.; Koicki, S.; Manasijevic, M.; Ivanovic, N.; Koteski, V.; Milosevic, Z.; Radisavljevic, I.; Cavor, J.; Novakovic, N.; Marjanovic, D.

    2001-01-01

    A 2-BaF 2 detector - fast slow time spectrometer for time differential perturbed angular correlations (TDPAC) experiments is described. This apparatus has been developed in the Group for Hyperfine Interactions in the Institute for Nuclear Sciences in VINCA. The excellent time resolution combined with high efficiency offered by these detectors enables one high counting rate performance and is operating in the wide temperature range 78-1200 K. (author)

  11. Position-sensitive superconductor detectors

    International Nuclear Information System (INIS)

    Kurakado, M.; Taniguchi, K.

    2016-01-01

    Superconducting tunnel junction (STJ) detectors and superconducting transition- edge sensors (TESs) are representative superconductor detectors having energy resolutions much higher than those of semiconductor detectors. STJ detectors are thin, thereby making it suitable for detecting low-energy X rays. The signals of STJ detectors are more than 100 times faster than those of TESs. By contrast, TESs are microcalorimeters that measure the radiation energy from the change in the temperature. Therefore, signals are slow and their time constants are typically several hundreds of μs. However, TESs possess excellent energy resolutions. For example, TESs have a resolution of 1.6 eV for 5.9-keV X rays. An array of STJs or TESs can be used as a pixel detector. Superconducting series-junction detectors (SSJDs) comprise multiple STJs and a single-crystal substrate that acts as a radiation absorber. SSJDs are also position sensitive, and their energy resolutions are higher than those of semiconductor detectors. In this paper, we give an overview of position-sensitive superconductor detectors.

  12. Simulation and optimisation of the Transition Radiation Tracker of the ATLAS detector, calibration and alignment of the detector with cosmic data. Estimation of the production cross-sections of the following decays: W → eν and Z → ee at LHC

    International Nuclear Information System (INIS)

    Goulette, M.

    2009-01-01

    This thesis was completed within the Transition Radiation Tracker (TRT) group of the ATLAS experiment at CERN, between January 2006 and May 2009. This work has been done during the last years of the construction of the LHC experiments, before data taking, expected for the winter 2009/2010. After a short introduction in particle physics, the thesis describes the ATLAS experiment and in particular its inner detector and TRT. This report can be divided into four main parts. First, work on the TRT simulation has been done. Results include some geometry definition, as well as some estimates and measurements of the TRT barrel and end-caps weight. The detector performances are studied in a second part, to measure the electrons energy (E) and scalar momentum (p) . Using some E/p distributions, a work on the determination of the amount of material and the residual misalignments is presented. In the third part, an estimate of the systematic uncertainty due to the acceptance corrections on the W → eν and Z → ee cross-section measurements is given. The last part contains an analysis of cosmic ray data in the TRT. The first results on the wire-by-wire alignment are presented. (author)

  13. The D0 detector upgrade

    International Nuclear Information System (INIS)

    Bross, A.D.

    1995-02-01

    The Fermilab collider program is undergoing a major upgrade of both the accelerator complex and the two detectors. Operation of the Tevatron at luminosities upwards of ten time that currently provided will occur in early 1999 after the commissioning of the new Fermilab Main Injector. The D0 upgrade program has been established to deliver a detector that will meet the challenges of this environment. A new magnetic tracker consisting of a superconducting solenoid, a silicon vertex detector, a scintillating fiber central tracker, and a central preshower detector will replace the current central tracking and transition radiation chambers. We present the design and performance capabilities of these new systems and describe results from physics simulations that demonstrate the physics reach of the upgraded detector

  14. A new self-powered flux detector

    International Nuclear Information System (INIS)

    Allan, C.J.

    1979-11-01

    It has been found that an Inconel-Inconel coaxial cable can be used as a fast-responding, neutron, self-powered flux detector if the core wire is sufficiently large. Test results obtained with such a detector, having a core wire approximately 1.5 mm in diameter, are presented. Other materials suitable for use as an emitter material, in such a relatively large diameter detector, also are included. (auth)

  15. Cryogenic detectors

    International Nuclear Information System (INIS)

    Zehnder, A.

    1987-01-01

    Presently the development of new large scale detector systems, used in very high energy physics experiments, is very active. In the low energy range, the introduction of charge coupled devices allows improved spacial and energy resolution. In the keV region, high resolution can only be achieved via the well established diffraction spectrometers with the well-known disadvantage of a small throughput. There exist no efficient detectors for non-ionizing radiation such as coherent nuclear scattering of weakly interacting particles. The development of high resolution solid state detectors in the keV-region with the possibility of nuclear recoil detection is therefore highly desired. Such detectors applied in astro and particle physics would thus allow one to obtain new information not achievable otherwise. Three types of cryogenic detectors exist: Calorimeters/Bolometers. This type is sensitive to the produced excess phonons and measures the deposited energy by detecting the heat pulses. Excess charge carriers should be used to produce phonons. Tunneling junctions. This type is sensitive to excess charge produced by the Cooper pair breakup. Excess phonons should be used to break up Cooper pairs. Superheated superconducting granules (SSG). An SSG detector consists of granules, the metastability of which is disturbed by radiation. The Meissner effect then causes a change in the field distribution of the applied external field, which can be detected. The present paper discusses the basic principle of calorimetric and tunneling junction detectors and some of their applications. 26 refs., 7 figs., 1 tab

  16. 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

  17. Hydrogen detector

    International Nuclear Information System (INIS)

    Kumagaya, Hiromichi; Yoshida, Kazuo; Sanada, Kazuo; Chigira, Sadao.

    1994-01-01

    The present invention concerns a hydrogen detector for detecting water-sodium reaction. The hydrogen detector comprises a sensor portion having coiled optical fibers and detects hydrogen on the basis of the increase of light transmission loss upon hydrogen absorption. In the hydrogen detector, optical fibers are wound around and welded to the outer circumference of a quartz rod, as well as the thickness of the clad layer of the optical fiber is reduced by etching. With such procedures, size of the hydrogen detecting sensor portion can be decreased easily. Further, since it can be used at high temperature, diffusion rate is improved to shorten the detection time. (N.H.)

  18. Fast beam radiofrequency spectroscopy

    International Nuclear Information System (INIS)

    Pipkin, F.M.

    1983-01-01

    The combination of a fast atom or ion beam derived from a small accelerator with radiofrequency spectroscopy methods provides a powerful method for measuring the fine structure of atomic and molecular systems. The fast beam makes possible measurements in which two separated oscillatory fields are used to obtain resonance lines whose widths are less than the natural line width due to the lifetimes of the states. The separated oscillatory field lines have, in addition, a number of features which make possible measurements with greater precision and less sensitivity to systematic errors. The fast beam also makes accessible multiple photon radiofrequency transitions whose line width is intrinsically narrower than that of the single photon transitions and which offer great potential for high precision measurements. This report focuses on the techniques and their promise. Recent measurements of the fine structure of H and He + are used as illustrations

  19. A search for lepton flavor violating transitions e τ via leptoquarks in e+p scattering with the ZEUS detector at HERA

    International Nuclear Information System (INIS)

    Kerger, R.

    2001-03-01

    A search for lepton flavor violation e + p → τX under the leptoquark (LQ) assumption has been performed with the ZEUS detector at HERA using the 1994 to 1997 data corresponding to an integrated luminosity of 47.7 pb -1 . Special effort has been made to identify the hadronic decay modes of the τ. No evidence for lepton flavor violation was found. For resonantly produced leptoquarks, limits on λ eq i x √(BR(LQ → lq j )) as well as on their Yukawa couplings λ eq i and λ τq j as a function of the leptoquark mass have been set. Assuming couplings of electromagnetic strength, λ = 0.3, leptoquarks for masses up to 285 GeV are excluded at 95% C.L. and assuming vice-versa leptoquarks of M LQ = 250 GeV, λ x √(BR) down to 3 . 10 -2 is excluded at 95% C.L. For leptoquarks with M LQ >> √(s), limits are set on the four-fermion contact interaction term λ eq i λ lq j /M LQ 2 . Many of these limits supersede existing limits from low-energy experiments. (orig.)

  20. DUMAND detector

    CERN Multimedia

    This object is one of the 256 other detectors of the DUMAND (Deep Underwater Muon And Neutrino Detection) experiment. The goal of the experiment was the construction of the first deep ocean high energy neutrino detector, to be placed at 4800 m depth in the Pacific Ocean off Keahole Point on the Big Island of Hawaii. A few years ago, a European conference with Cosmic experiments was organized at CERN as they were projects like DUMAND in Hawaii. Along with the conference, a temporary exhibition was organised as well. It was a collaboration of institutions from Germany, Japan, Switzerland and the U.S.A. CERN had borrowed equipment and objects from different institutes around the world, including this detector of the DUMAND experiment. Most of the equipment were sent back to the institutes, however this detector sphere was offered to a CERN member of the personnel.

  1. Detector applications

    International Nuclear Information System (INIS)

    Pehl, R.H.

    1977-10-01

    Semiconductor detectors are now applied to a very wide range of problems. The combination of relatively low cost, excellent energy resolution, and simultaneous broad energy-spectrum analysis is uniquely suited to many applications in both basic and applied physics. Alternative techniques, such as magnetic spectrometers for charged-particle spectroscopy, while offering better energy resolution, are bulky, expensive, and usually far more difficult to use. Furthermore, they do not directly provide the broad energy-spectrum measurements easily accomplished using semiconductor detectors. Scintillation detectors, which are approximately equivalent to semiconductor detectors in convenience and cost, exhibit 10 to 100 times worse energy resolution. However, their high efficiency and large potential size recommend their use in some measurements

  2. Smoke detectors

    International Nuclear Information System (INIS)

    Bryant, J.; Howes, J.H.; Smout, D.W.S.

    1979-01-01

    A smoke detector is described which provides a smoke sensing detector and an indicating device and in which a radioactive substance is used in conjunction with two ionisation chambers. The system includes an outer electrode, a collector electrode and an inner electrode which is made of or supports the radioactive substance which, in this case, is 241 Am. The invention takes advantage of the fact that smoke particles can be allowed to enter freely the inner ionisation chamber. (U.K.)

  3. Radiation detector

    International Nuclear Information System (INIS)

    Gillies, W.

    1980-01-01

    The radiation detector for measuring e.g. a neutron flux consists of a central emitter, an insulating shell arranged around it, and a tube-shaped collector enclosing both. The emitter itself is composed of a great number of stranded, spiral wires of small diameter giving a defined flexibility to the detector. For emitter material Pt, Rh, V, Co, Ce, Os or Ta may be used. (DG) [de

  4. Split detector

    International Nuclear Information System (INIS)

    Cederstrand, C.N.; Chism, H.R.

    1982-01-01

    A gas analyzer is disclosed which provides a dual channel capability for the simultaneous determination of the presence and concentration of two gases in a stream of sample gas and which has a single infrared source, a single sample cell, two infrared bandpass filters, and two infrared detectors. A separator between the filters and detectors prevents interchange of radiation between the filters. The separator is positioned by fitting it in a slot

  5. Neutron detector for fusion reaction-rate measurements

    International Nuclear Information System (INIS)

    Lerche, R.A.; Phillion, D.W.; Tietbohl, G.L.

    1993-01-01

    We have developed a fast, sensitive neutron detector for recording the fusion reaction-rate history of inertial-confinement fusion (ICF) experiments. The detector is based on the fast rise-time of a commercial plastic scintillator (BC-422) and has a response 7 neutrons

  6. CMS Pixel Detector Upgrade

    CERN Document Server

    INSPIRE-00038772

    2011-01-01

    The present Compact Muon Solenoid silicon pixel tracking system has been designed for a peak luminosity of 1034cm-2s-1 and total dose corresponding to two years of the Large Hadron Collider (LHC) operation. With the steady increase of the luminosity expected at the LHC, a new pixel detector with four barrel layers and three endcap disks is being designed. We will present the key points of the design: the new geometry, which minimizes the material budget and increases the tracking points, and the development of a fast digital readout architecture, which ensures readout efficiency even at high rate. The expected performances for tracking and vertexing of the new pixel detector are also addressed.

  7. Upgrading ATLAS Fast Calorimeter Simulation

    CERN Document Server

    Heath, Matthew Peter; The ATLAS collaboration

    2017-01-01

    Producing the very large samples of simulated events required by many physics and performance studies with the ATLAS detector using the full GEANT4 detector simulation is highly CPU intensive. Fast simulation tools are a useful way of reducing CPU requirements when detailed detector simulations are not needed. During the LHC Run-1, a fast calorimeter simulation (FastCaloSim) was successfully used in ATLAS. FastCaloSim provides a simulation of the particle energy response at the calorimeter read-out cell level, taking into account the detailed particle shower shapes and the correlations between the energy depositions in the various calorimeter layers. It is interfaced to the standard ATLAS digitization and reconstruction software, and it can be tuned to data more easily than Geant4. Now an improved version of FastCaloSim is in development, incorporating the experience with the version used during Run-1. The new FastCaloSim aims to overcome some limitations of the first version by improving the description of s...

  8. Fast Calorimeter Simulation in ATLAS

    CERN Document Server

    Schaarschmidt, Jana; The ATLAS collaboration

    2017-01-01

    Producing the very large samples of simulated events required by many physics and performance studies with the ATLAS detector using the full GEANT4 detector simulation is highly CPU intensive. Fast simulation tools are a useful way of reducing CPU requirements when detailed detector simulations are not needed. During the LHC Run-1, a fast calorimeter simulation (FastCaloSim) was successfully used in ATLAS. FastCaloSim provides a simulation of the particle energy response at the calorimeter read-out cell level, taking into account the detailed particle shower shapes and the correlations between the energy depositions in the various calorimeter layers. It is interfaced to the standard ATLAS digitization and reconstruction software, and it can be tuned to data more easily than GEANT4. It is 500 times faster than full simulation in the calorimeter system. Now an improved version of FastCaloSim is in development, incorporating the experience with the version used during Run-1. The new FastCaloSim makes use of mach...

  9. FATRAS - the ATLAS Fast Track Simulation project

    NARCIS (Netherlands)

    Mechnich, J.

    2011-01-01

    The Monte Carlo simulation of the detector response is an integral component of any analysis performed with data from the LHC experiments. As these simulated data sets must be both large and precise, their production is a CPU-intensive task. ATLAS has developed full and fast detector simulation

  10. Hyperfine structure of 87,89Sr 5s4d3D-5snf transitions in collinear fast beam RIMS

    International Nuclear Information System (INIS)

    Bushaw, B. A.; Kluge, H.-J.; Lantzsch, J.; Schwalbach, R.; Schwarz, M.; Stenner, J.; Stevens, H.; Wendt, K.; Zimmer, K.

    1995-01-01

    The title transition, with n=20, 23, and 32 were measured for stable 87 Sr and the observed hfs was interpreted and strong hyperfine mixing of all four terms 1 F3 and 3 F2,3,4 in the upper configuration. The results of the analysis were used to predict the hfs for the radioactive isotope 89 Sr. Measurement were then performed on samples containing 10 9 atoms 89 Sr. The positions and intensities of the hfs components selected for study were found to agree well with the predicted values

  11. Combining two major ATLAS inner detector components

    CERN Multimedia

    Maximilien Brice

    2006-01-01

    The semiconductor tracker is inserted into the transition radiation tracker for the ATLAS experiment at the LHC. These make up two of the three major components of the inner detector. They will work together to measure the trajectories produced in the proton-proton collisions at the centre of the detector when the LHC is switched on in 2008.

  12. Shaped detector

    International Nuclear Information System (INIS)

    Carlson, R.W.

    1981-01-01

    A radiation detector or detector array which has a non-constant spatial response, is disclosed individually and in combination with a tomographic scanner. The detector has a first dimension which is oriented parallel to the plane of the scan circle in the scanner. Along the first dimension, the detector is most responsive to radiation received along a centered segment of the dimension and less responsive to radiation received along edge segments. This non-constant spatial response can be achieved in a detector comprised of a scintillation crystal and a photoelectric transducer. The scintillation crystal in one embodiment is composed of three crystals arranged in layers, with the center crystal having the greatest light conversion efficiency. In another embodiment, the crystal is covered with a reflective substance around the center segment and a less reflective substance around the remainder. In another embodiment, an optical coupling which transmits light from adjacent the center segment with the greatest intensity couples the scintillation crystal and the photoelectric transducer. In yet another embodiment, the photoelectric transducer comprises three photodiodes, one receiving light produced adjacent the central segment and the other two receiving light produced adjacent the edge segments. The outputs of the three photodiodes are combined with a differential amplifier

  13. A Physical Model-based Correction for Charge Traps in the Hubble Space Telescope ’s Wide Field Camera 3 Near-IR Detector and Its Applications to Transiting Exoplanets and Brown Dwarfs

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Yifan; Apai, Dániel; Schneider, Glenn [Department of Astronomy/Steward Observatory, The University of Arizona, 933 N. Cherry Avenue, Tucson, AZ 85721 (United States); Lew, Ben W. P., E-mail: yzhou@as.arizona.edu [Department of Planetary Science/Lunar and Planetary Laboratory, The University of Arizona, 1640 E. University Boulevard, Tucson, AZ 85718 (United States)

    2017-06-01

    The Hubble Space Telescope Wide Field Camera 3 (WFC3) near-IR channel is extensively used in time-resolved observations, especially for transiting exoplanet spectroscopy as well as brown dwarf and directly imaged exoplanet rotational phase mapping. The ramp effect is the dominant source of systematics in the WFC3 for time-resolved observations, which limits its photometric precision. Current mitigation strategies are based on empirical fits and require additional orbits to help the telescope reach a thermal equilibrium . We show that the ramp-effect profiles can be explained and corrected with high fidelity using charge trapping theories. We also present a model for this process that can be used to predict and to correct charge trap systematics. Our model is based on a very small number of parameters that are intrinsic to the detector. We find that these parameters are very stable between the different data sets, and we provide best-fit values. Our model is tested with more than 120 orbits (∼40 visits) of WFC3 observations and is proved to be able to provide near photon noise limited corrections for observations made with both staring and scanning modes of transiting exoplanets as well as for starting-mode observations of brown dwarfs. After our model correction, the light curve of the first orbit in each visit has the same photometric precision as subsequent orbits, so data from the first orbit no longer need to be discarded. Near-IR arrays with the same physical characteristics (e.g., JWST/NIRCam ) may also benefit from the extension of this model if similar systematic profiles are observed.

  14. BES detector

    International Nuclear Information System (INIS)

    Bai, J.Z.; Bian, Q.; Chen, G.M.; Chen, L.J.; Chen, S.N.; Chen, Y.Q.; Chen, Z.Q.; Chi, Y.K.; Cui, H.C.; Cui, X.Z.; Deng, S.S.; Deng, Y.W.; Ding, H.L.; Dong, B.Z.; Dong, X.S.; Du, X.; Du, Z.Z.; Feng, C.; Feng, Z.; Fu, Z.S.; Gao, C.S.; Gao, M.L.; Gao, S.Q.; Gao, W.X.; Gao, Y.N.; Gu, S.D.; Gu, W.X.; Guan, Y.Z.; Guo, H.F.; Guo, Y.N.; Guo, Y.Y.; Han, S.W.; Han, Y.; Hao, W.; He, J.; He, K.R.; He, M.J.; Hou, X.J.; Hu, G.Y.; Hu, J.S.; Hu, J.W.; Huang, D.Q.; Huang, Y.Z.; Jia, Q.P.; Jiang, C.H.; Ju, Q.; Lai, Y.F.; Lang, P.F.; Li, D.S.; Li, F.; Li, H.; Li Jia; Li, J.T.; Li Jin; Li, L.L.; Li, P.Q.; Li, Q.M.; Li, R.B.; Li, S.Q.; Li, W.; Li, W.G.; Li, Z.X.; Liang, G.N.; Lin, F.C.; Lin, S.Z.; Lin, W.; Liu, Q.; Liu, R.G.; Liu, W.; Liu, X.; Liu, Z.A.; Liu, Z.Y.; Lu, C.G.; Lu, W.D.; Lu, Z.Y.; Lu, J.G.; Ma, D.H.; Ma, E.C.; Ma, J.M.; Mao, H.S.; Mao, Z.P.; Meng, X.C.; Ni, H.L.; Nie, J.; Nie, Z.D.; Niu, W.P.; Pan, L.J.; Qi, N.D.; Qian, J.J.; Qu, Y.H.; Que, Y.K.; Rong, G.; Ruan, T.Z.; Shao, Y.Y.; Shen, B.W.; Shen, D.L.; Shen, J.; Sheng, H.Y.; Sheng, J.P.; Shi, H.Z.; Song, X.F.; Sun, H.S.; Tang, F.K.; Tang, S.Q.; Tian, W.H.; Wang, F.; Wang, G.Y.; Wang, J.G.; Wang, J.Y.; Wang, L.S.; Wang, L.Z.; Wang, M.; Wang, P.; Wang, P.L.; Wang, S.M.; Wang, S.Q.; Wang, T.J.; Wang, X.W.; Wang, Y.Y.; Wang, Z.H.; Wang, Z.J.; Wei, C.L.; Wei, Z.Z.; Wu, J.W.; Wu, S.H.; Wu, S.Q.; Wu, W.M.; Wu, X.D.; Wu, Z.D.; Xi, D.M.; Xia, X.M.; Xiao, J.; Xie, P.P.; Xie, X.X.; Xu, J.G.; Xu, R.S.; Xu, Z.Q.; Xuan, B.C.; Xue, S.T.; Yan, J.; Yan, S.P.; Yan, W.G.; Yang, C.Z.; Yang, C.M.; Yang, C.Y.; Yang, X.F.; Yang, X.R.; Ye, M.H.; Yu, C.H.; Yu, C.S.; Yu, Z.Q.; Zhang, B.Y.; Zhang, C.D.; Zhang, C.C.; Zhang, C.Y.; Zhang, D.H.; Zhang, G.; Zhang, H.Y.; Zhang, H.L.; Zhang, J.W.; Zhang, L.S.; Zhang, S.Q.; Zhang, Y.P.; Zhang, Y.; Zhang, Y.M.; Zhao, D.X.; Zhao, J.W.; Zhao, M.; Zhao, P.D.; Zhao, P.P.; Zhao, W.R.; Zhao, Z.G.; Zhao, Z.Q.; Zheng, J.P.; Zheng, L.S.; Zheng, M.; Zheng, W.S.; Zheng, Z.P.; Zhong, G.P.; Zhou, G.P.; Zhou, H.S.; Zhou, J.; Zhou Li; Zhou Lin; Zhou, M.; Zhou, Y.S.; Zhou, Y.H.; Zhu, G.S.; Zhu, Q.M.; Zhu, S.G.; Zhu, Y.C.; Zhu, Y.S.; Zhuang, B.A.

    1994-01-01

    The Beijing Spectrometer (BES) is a general purpose solenoidal detector at the Beijing Electron Positron Collider (BEPC). It is designed to study exclusive final states in e + e - annihilations at the center of mass energy from 3.0 to 5.6 GeV. This requires large solid angle coverage combined with good charged particle momentum resolution, good particle identification and high photon detection efficiency at low energies. In this paper we describe the construction and the performance of BES detector. (orig.)

  15. Development of Fast, Background-Limited Transition-Edge Sensors for the Background-Limited Infrared/Sub-Millimetre Spectrograph (BLISS) for SPICA

    Science.gov (United States)

    Beyer, Andrew D.; Runyan, M. C.; Kenyon, M.; Echternach, P. M.; Chui, T.; Bumble, B.; Bradford, C. M.; Holmes, W. A.; Bock, J. J.

    2012-01-01

    We report experimental progress toward demonstrating background-limited arrays of membrane-isolated transition-edge sensors (TESs) for the Background Limited Infrared/Sub-mm Spectrograph (BLISS). BLISS is a space-borne instrument with grating spectrometers for wavelengths lambda = 35-435 microns and with R = lambda/(delta)lambda approx. 500. The goals for BLISS TESs are: noise equivalent power (NEP) = 5x10(exp -20) W/Hz(1/2) and response time t or = 135mK) and Mo/Cu proximitized bilayers, where T(sub c) is the thermistor transition temperature. We measured the Ir TES arrays in our 50mK adiabatic demagnetization refrigerator test system, which can measure up to eight 1x32 arrays simultaneously using a time-division multiplexer, as well as our single-pixel test system which can measure down to 15mK. In our previous Ir array measurements our best reported performance was NEP=2.5x10(exp -19) W/Hz(1/2) and tapprox.5ms for straight-beam TESs. In fact, we expected NEPapprox.1.5x10(exp -19)W/Hz(1/2) for meander beam TESs, but did not achieve this previously due to 1/f noise. Here, we detail improvements toward measuring the expected NEP and demonstrate NEP=(1.3+0.2)x10(exp -19)W/Hz(1/2) in our single-pixel test system and NEP=(1.6+0.3)x10(exp -19)W/Hz(1/2) in our array test system.

  16. Development of Fast, Background-Limited Transition-Edge Sensors for the Background-Limited Infrared/Sub-mm Spectrograph (BLISS) for SPICA

    Science.gov (United States)

    Beyer, Andrew D.; Runyan, M. C.; Kenyon, M.; Echternach, P. M .; Chui, T.; Bumble, B.; Bradford, C. M.; Holmes, W. A.; Bock, J. J.

    2012-01-01

    We report experimental progress toward demonstrating background-limited arrays of membrane-isolated transition-edge sensors (TESs) for the Background Limited Infrared/Sub-mm Spectrograph (BLISS). BLISS is a space-borne instrument with grating spectrometers for wavelengths lambda=35-435 micron and with R=lambda/delta lambda approximately equals 500. The goals for BLISS TESs are: noise equivalent power (NEP) = 5x10 (sup -20) W/Hz(exp 1/2) and response time tau = 135mK) and Mo/Cu proximitized bilayers, where T(sub c) is the thermistor transition temperature. We measured the Ir TES arrays in our 50mK adiabatic demagnetization refrigerator test system, which can measure up to eight 1x32 arrays simultaneously using a time-division multiplexer, as well as our single-pixel test system which can measure down to 15mK. In our previous Ir array measurements our best reported performance was NEP=2.5x10(exp -19) W/Hz(sub 1/2) and Tau approximately equals 5ms for straight-beam TESs. In fact, we expected NEP approximately equals 1.5x10(exp -19)?W/Hz(sup 1/2) for meander beam TESs, but did not achieve this previously due to 1/f noise. Here, we detail improvements toward measuring the expected NEP and demonstrate NEP=(1.3+0.2)x10 (sup -19)W/Hz(exp 1/2) in our single-pixel test system and NEP=(1.6+/-0.3)x10(sup -19)W/Hz(sup 1/2) in our array test system.

  17. Bottom Fixed Platform Dynamics Models Assessing Surface Ice Interactions for Transitional Depth Structures in the Great Lakes: FAST8 – IceDyn

    Energy Technology Data Exchange (ETDEWEB)

    Karr, Dale G. [Univ. of Michigan, Ann Arbor, MI (United States); Yu, Bingbin [Principle Power, Inc., Emeryville, CA (United States); Sirnivas, Senu [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2015-04-01

    To create long-term solutions for offshore wind turbines in a variety of environmental conditions, CAE tools are needed to model the design-driving loads that interact with an offshore wind turbine system during operation. This report describes our efforts in augmenting existing CAE tools used for offshore wind turbine analysis with a new module that can provide simulation capabilities for ice loading on the system. This augmentation was accomplished by creating an ice-loading module coupled to FAST8, the CAE tool maintained by the NREL for simulating land-based and offshore wind turbine dynamics. The new module includes both static and dynamic ice loading that can be applied during a dynamic simulation of the response of an offshore wind turbine. The ice forces can be prescribed, or influenced by the structure’s compliant response, or by the dynamics of both the structure and the ice floe. The new module covers ice failure modes of spalling, buckling, crushing, splitting, and bending. The supporting structure of wind turbines can be modeled as a vertical or sloping form at the waterline. The Inward Battered Guide Structure (IBGS) foundation designed by Keystone Engineering for the Great Lakes was used to study the ice models coupled to FAST8. The IBGS foundation ice loading simulations in FAST8 were compared to the baseline simulation case without ice loading. The ice conditions reflecting those from Lake Huron at Port Huron and Lake Michigan at North Manitou were studied under near rated wind speed of 12 m/s for the NREL 5-MW reference turbine. Simulations were performed on ice loading models 1 through 4 and ice model 6 with their respective sub-models. The purpose of ice model 5 is to investigate ice loading on sloping structures such as ice-cones on a monopile and is not suitable for multi-membered jacketed structures like the IBGS foundation. The key response parameters from the simulations, shear forces and moments from the tower base and IBGS foundation

  18. Studies on neutron detection with solid state nuclear track detectors

    International Nuclear Information System (INIS)

    Khouri, M.C.; Vilela, E.C.; Andrade, C. de.

    1993-03-01

    The detection of thermal and fast neutrons was studied. For thermal neutrons, alpha sensitive plastic was used in order to register the products of nuclear reactions taking place in boron and /or lithium converters. Fast neutrons produce recoil tracks within the detector. In the present case, CR-39 and Makrofol E were used. Chemical and electrochemical etching processes were used for thermal and fast neutron detectors, respectively. (F.E.). 6 refs, 4 figs, 6 tabs

  19. Optimisation of selection cuts for MUCH detector of CBM experiment

    International Nuclear Information System (INIS)

    Farooq, M.; Ahmad, S.; Chattopadhyay, S.

    2015-01-01

    The Compressed Baryonic Matter (CBM) experiment is one of the future research program scheduled at FAIR, Darmstadt Germany. The aim of the planned experiment is to explore the Quantum Chromodynamics (QCD) phase diagram in the regions of high baryonic densities and moderate temperatures in the beam energy range of 10-45 AGeV. This approach is complementary to the studies of matter at high temperatures and low net baryon densities performed at RHIC and LHC. CBM will also search for the critical point, the first order deconfinement phase transition from the hadronic matter to the partonic matter and the study of equation-of-state of dense baryonic matter. Comprehensive scan of observables, beam energies and collision systems is realised. The observables include: low mass dilepton pairs, charmonia and open charm, collective flow of rare and bulk particles, correlations and fluctuations etc. Low yield measurements of rare probes, like charmonium and low mass vector mesons, have to be performed at very high reaction rates ∼10 MHz. These conditions demand for fast and radiation hard detectors and associated fast electronics, readout and online event reconstruction. Low material budget is required with in the detector acceptance to avoid multiple scattering which would limit high precision measurements

  20. Smoke detectors

    International Nuclear Information System (INIS)

    Macdonald, E.

    1976-01-01

    A smoke detector is described consisting of a ventilated ionisation chamber having a number of electrodes and containing a radioactive source in the form of a foil supported on the surface of the electrodes. This electrode consists of a plastic material treated with graphite to render it electrically conductive. (U.K.)