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Sample records for number resolving detector

  1. Photon number projection using non-number-resolving detectors

    International Nuclear Information System (INIS)

    Rohde, Peter P; Webb, James G; Huntington, Elanor H; Ralph, Timothy C

    2007-01-01

    Number-resolving photo-detection is necessary for many quantum optics experiments, especially in the application of entangled state preparation. Several schemes have been proposed for approximating number-resolving photo-detection using non-number-resolving detectors. Such techniques include multi-port detection and time-division multiplexing. We provide a detailed analysis and comparison of different number-resolving detection schemes, with a view to creating a useful reference for experimentalists. We show that the ideal architecture for projective measurements is a function of the detector's dark count and efficiency parameters. We also describe a process for selecting an appropriate topology given actual experimental component parameters

  2. Discrimination of binary coherent states using a homodyne detector and a photon number resolving detector

    DEFF Research Database (Denmark)

    Wittmann, Christoffer; Andersen, Ulrik Lund; Takeoka, Masahiro

    2010-01-01

    We investigate quantum measurement strategies capable of discriminating two coherent states probabilistically with significantly smaller error probabilities than can be obtained using nonprobabilistic state discrimination. We apply a postselection strategy to the measurement data of a homodyne...... detector as well as a photon number resolving detector in order to lower the error probability. We compare the two different receivers with an optimal intermediate measurement scheme where the error rate is minimized for a fixed rate of inconclusive results. The photon number resolving (PNR) receiver...

  3. Quantum random-number generator based on a photon-number-resolving detector

    International Nuclear Information System (INIS)

    Ren Min; Wu, E; Liang Yan; Jian Yi; Wu Guang; Zeng Heping

    2011-01-01

    We demonstrated a high-efficiency quantum random number generator which takes inherent advantage of the photon number distribution randomness of a coherent light source. This scheme was realized by comparing the photon flux of consecutive pulses with a photon number resolving detector. The random bit generation rate could reach 2.4 MHz with a system clock of 6.0 MHz, corresponding to a random bit generation efficiency as high as 40%. The random number files passed all the stringent statistical tests.

  4. Absolute calibration of photon-number-resolving detectors with an analog output using twin beams

    Czech Academy of Sciences Publication Activity Database

    Peřina Jr., J.; Haderka, Ondřej; Allevi, A.; Bondani, M.

    2014-01-01

    Roč. 104, č. 4 (2014), "041113-1"-"041113-4" ISSN 0003-6951 R&D Projects: GA ČR GAP205/12/0382 Institutional support: RVO:68378271 Keywords : photon- number resolving detector * twin beams * photon fields Subject RIV: BH - Optics, Masers, Lasers Impact factor: 3.302, year: 2014

  5. On-chip, photon-number-resolving, telecommunication-band detectors for scalable photonic information processing

    Energy Technology Data Exchange (ETDEWEB)

    Gerrits, Thomas; Lita, Adriana E.; Calkins, Brice; Tomlin, Nathan A.; Fox, Anna E.; Linares, Antia Lamas; Mirin, Richard P.; Nam, Sae Woo [National Institute of Standards and Technology, Boulder, Colorado, 80305 (United States); Thomas-Peter, Nicholas; Metcalf, Benjamin J.; Spring, Justin B.; Langford, Nathan K.; Walmsley, Ian A. [Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU (United Kingdom); Gates, James C.; Smith, Peter G. R. [Optoelectronics Research Centre, University of Southampton, Highfield SO17 1BJ (United Kingdom)

    2011-12-15

    Integration is currently the only feasible route toward scalable photonic quantum processing devices that are sufficiently complex to be genuinely useful in computing, metrology, and simulation. Embedded on-chip detection will be critical to such devices. We demonstrate an integrated photon-number-resolving detector, operating in the telecom band at 1550 nm, employing an evanescently coupled design that allows it to be placed at arbitrary locations within a planar circuit. Up to five photons are resolved in the guided optical mode via absorption from the evanescent field into a tungsten transition-edge sensor. The detection efficiency is 7.2{+-}0.5 %. The polarization sensitivity of the detector is also demonstrated. Detailed modeling of device designs shows a clear and feasible route to reaching high detection efficiencies.

  6. Discrimination of optical coherent states using a photon number resolving detector

    DEFF Research Database (Denmark)

    Wittmann, C.; Andersen, Ulrik Lund; Leuchs, G.

    2010-01-01

    The discrimination of non-orthogonal quantum states with reduced or without errors is a fundamental task in quantum measurement theory. In this work, we investigate a quantum measurement strategy capable of discriminating two coherent states probabilistically with significantly smaller error...... probabilities than can be obtained using non-probabilistic state discrimination. We find that appropriate postselection of the measurement data of a photon number resolving detector can be used to discriminate two coherent states with small error probability. We compare our new receiver to an optimal...

  7. Noise-free high-efficiency photon-number-resolving detectors

    International Nuclear Information System (INIS)

    Rosenberg, Danna; Lita, Adriana E.; Miller, Aaron J.; Nam, Sae Woo

    2005-01-01

    High-efficiency optical detectors that can determine the number of photons in a pulse of monochromatic light have applications in a variety of physics studies, including post-selection-based entanglement protocols for linear optics quantum computing and experiments that simultaneously close the detection and communication loopholes of Bell's inequalities. Here we report on our demonstration of fiber-coupled, noise-free, photon-number-resolving transition-edge sensors with 88% efficiency at 1550 nm. The efficiency of these sensors could be made even higher at any wavelength in the visible and near-infrared spectrum without resulting in a higher dark-count rate or degraded photon-number resolution

  8. Ultrafast photon number resolving detector with a temperature stabilized si multi pixel photon counter

    Energy Technology Data Exchange (ETDEWEB)

    Song, Minsoo; Hong, Eugene; Won, Eunil; Yoon, Tai Hyun [Korea Univ., Seoul (Korea, Republic of)

    2008-11-15

    Quantum information science has been rapidly progressed and matured and matured thanks to the recent developments of the single photon detection technologies. Single photon detectors such as a Si avalanche photo diode(APD)in the infrared, an InGaAs/InP APD in the telecommunication band, and a super conducting transient edge sensor(TES)in the broad region of the spectrum have been widely used. Single photon detectors, however, operating at the ultraviolet to visible (370nm∼800nm)regions has not been actively investigated partly due to the lack of single photon and/or entangled photon sources and the lack of solid state single photon detectors. In this paper, we investigate the single photon detection characteristics of a Si multi pixel photon counter(MPPC), which has a high spectral responsivity between 300nm to 800nm, as a photon number resolving solid state detector. Figure 1 shows the schematic diagram of the single photon detection set up at 399nm by using a temperature stabilized Si MPPC. The output beam of the laser being properly attenuated is directed to the MPPC module, at which fixed number of photo electrons corresponding to incident individual photon are generated at Geiger mode of the Si APD pixels. The detected photo current is converted into a digital signal by using a fast analog to digital converter and a digital oscilloscope stores the time sequence of the photo currents. Figure 2 shows the accumulated charges collected by MPPC at∼10.deg.C showing a clear single photon and two photons peaks, respectively, separated by ∼5 sigma of the coincidence counts at the two output ports of a Mach Zender interferometer as a function of optical path length difference. The research was supported by Seoul R and BD program(NT070127)and by the KRISS.

  9. Ultrafast photon number resolving detector with a temperature stabilized si multi pixel photon counter

    International Nuclear Information System (INIS)

    Song, Minsoo; Hong, Eugene; Won, Eunil; Yoon, Tai Hyun

    2008-01-01

    Quantum information science has been rapidly progressed and matured and matured thanks to the recent developments of the single photon detection technologies. Single photon detectors such as a Si avalanche photo diode(APD)in the infrared, an InGaAs/InP APD in the telecommunication band, and a super conducting transient edge sensor(TES)in the broad region of the spectrum have been widely used. Single photon detectors, however, operating at the ultraviolet to visible (370nm∼800nm)regions has not been actively investigated partly due to the lack of single photon and/or entangled photon sources and the lack of solid state single photon detectors. In this paper, we investigate the single photon detection characteristics of a Si multi pixel photon counter(MPPC), which has a high spectral responsivity between 300nm to 800nm, as a photon number resolving solid state detector. Figure 1 shows the schematic diagram of the single photon detection set up at 399nm by using a temperature stabilized Si MPPC. The output beam of the laser being properly attenuated is directed to the MPPC module, at which fixed number of photo electrons corresponding to incident individual photon are generated at Geiger mode of the Si APD pixels. The detected photo current is converted into a digital signal by using a fast analog to digital converter and a digital oscilloscope stores the time sequence of the photo currents. Figure 2 shows the accumulated charges collected by MPPC at∼10.deg.C showing a clear single photon and two photons peaks, respectively, separated by ∼5 sigma of the coincidence counts at the two output ports of a Mach Zender interferometer as a function of optical path length difference. The research was supported by Seoul R and BD program(NT070127)and by the KRISS

  10. Optimal sub-Poissonian light generation from twin beams by photon-number resolving detectors

    Czech Academy of Sciences Publication Activity Database

    Lamperti, M.; Allevi, A.; Bondani, M.; Machulka, R.; Michálek, Václav; Haderka, O.; Peřina Jr., J.

    2013-01-01

    Roč. 31, č. 1 (2013), s. 20-25 ISSN 0740-3224 R&D Projects: GA ČR GAP205/12/0382 Institutional support: RVO:68378271 Keywords : photon- number resolving * quantum correlation Subject RIV: BH - Optics, Masers, Lasers Impact factor: 1.806, year: 2013

  11. Analysis of a photon number resolving detector based on fluorescence readout of an ion Coulomb crystal quantum memory inside an optical cavity

    DEFF Research Database (Denmark)

    Clausen, Christoph; Sangouard, N.; Drewsen, M.

    2013-01-01

    The ability to detect single photons with a high efficiency is a crucial requirement for various quantum information applications. By combining the storage process of a quantum memory for photons with fluorescence-based quantum state measurement, it is, in principle, possible to achieve high......-efficiency photon counting in large ensembles of atoms. The large number of atoms can, however, pose significant problems in terms of noise stemming from imperfect initial state preparation and off-resonant fluorescence. We identify and analyse a concrete implementation of a photon number resolving detector based...... larger than 93%. Moderate experimental parameters allow for repetition rates of about 3 kHz, limited by the time needed for fluorescence collection and re-cooling of the ions between trials. Our analysis may lead to the first implementation of a photon number resolving detector in atomic ensembles....

  12. An x-ray detector for time-resolved studies

    International Nuclear Information System (INIS)

    Rodricks, B.; Brizard, C.; Clarke, R.; Lowe, W.

    1992-01-01

    The development of ultrahigh-brightness x-ray sources makes time-resolved x-ray studies more and more feasible. Improvements in x-ray optics components are also critical for obtaining the appropriate beam for a particular type of experiment. Moreover, fast parallel detectors will be essential in order to exploit the combination of high intensity x-ray sources and novel optics for time-resolved experiments. A CCD detector with a time resolution of microseconds has been developed at the Advanced Photon Source (APS). This detector is fully programmable using CAMAC electronics and a Micro Vax computer. The techniques of time-resolved x-ray studies, which include scattering, microradiography, microtomography, stroboscopy, etc., can be applied to a range of phenomena (including rapid thermal annealing, surface ordering, crystallization, and the kinetics of phase transition) in order to understand these time-dependent microscopic processes. Some of these applications will be illustrated by recent results performed at synchrotrons. New powerful x-ray sources now under construction offer the opportunity to apply innovative approaches in time-resolved work

  13. Time-resolved and position-resolved X-ray spectrometry with a pixelated detector

    Energy Technology Data Exchange (ETDEWEB)

    Sievers, Peter

    2012-12-07

    show a good agreement. Up to now the measurements of impinging spectra with a Timepix detector have been performed in radiation fields with a relatively high fluence. To cope with the requirement of measuring in radiation fields with a low fluence, there had to be changes in the method of analysis compared to those performed formerly. An important improvement in this context was the employment of the Bayesian deconvolution method. The spectra reconstructed with this method were then compared to the results of two different and established detection systems. Firstly, the shape of the deconvolved spectrum was compared to the one measured with a hpGe detector. Secondly, the calculated value of the kerma rate was compared to the one measured with an ionization chamber. This gave an estimate on the correctness of the absolute number of photons. Both comparisons have shown a good agreement and thus I was able to validate that the method delivers precise results. Compared to the formerly used spectrum-stripping method the Bayesian deconvolution turned out to be very stable and reliable. This robustness of the deconvolution method and the development of a pixel-by-pixel energy calibration were the keys towards position-resolved spectrometry. With such a precise energy calibration the energy resolution was enhanced by up to 45%. This improved accuracy in the measurement has been very demanding on the improvements of the simulation of the response matrix needed for deconvolution. Both this enhanced simulation and a pixel-by-pixel calibrated detector opened the possibility of measuring the anode heel effect. Not only the relative angular dependency of the spectrum emitted but also the change in the absolute photon fluence were measured. Furthermore, it is possible to even use small ROIs down to 4x4 pixels to evaluate a spectrum. This was then applied for the spectrometry of small focal spots of a miniature X-ray source used in therapeutics. Furthermore, the robustness and the

  14. Time-resolved and position-resolved X-ray spectrometry with a pixelated detector

    International Nuclear Information System (INIS)

    Sievers, Peter

    2012-01-01

    show a good agreement. Up to now the measurements of impinging spectra with a Timepix detector have been performed in radiation fields with a relatively high fluence. To cope with the requirement of measuring in radiation fields with a low fluence, there had to be changes in the method of analysis compared to those performed formerly. An important improvement in this context was the employment of the Bayesian deconvolution method. The spectra reconstructed with this method were then compared to the results of two different and established detection systems. Firstly, the shape of the deconvolved spectrum was compared to the one measured with a hpGe detector. Secondly, the calculated value of the kerma rate was compared to the one measured with an ionization chamber. This gave an estimate on the correctness of the absolute number of photons. Both comparisons have shown a good agreement and thus I was able to validate that the method delivers precise results. Compared to the formerly used spectrum-stripping method the Bayesian deconvolution turned out to be very stable and reliable. This robustness of the deconvolution method and the development of a pixel-by-pixel energy calibration were the keys towards position-resolved spectrometry. With such a precise energy calibration the energy resolution was enhanced by up to 45%. This improved accuracy in the measurement has been very demanding on the improvements of the simulation of the response matrix needed for deconvolution. Both this enhanced simulation and a pixel-by-pixel calibrated detector opened the possibility of measuring the anode heel effect. Not only the relative angular dependency of the spectrum emitted but also the change in the absolute photon fluence were measured. Furthermore, it is possible to even use small ROIs down to 4x4 pixels to evaluate a spectrum. This was then applied for the spectrometry of small focal spots of a miniature X-ray source used in therapeutics. Furthermore, the robustness and the

  15. Compton polarimetry with position-resolving X-ray detectors

    International Nuclear Information System (INIS)

    Hess, Sebastian

    2010-02-01

    In the present thesis the prototype of a novel position-resolving and multi-hit able 2D Si(Li) strip detector is characterized, the planar detector crystal of which is simultaneously applied both as scatterer and as absorber. In the framework of this thesis the Si(Li) polarimeter could be applied in different experiments on the radiative electron capture and on the characteristic radiation at the experimental storage ring of the GSI. The characterization of the detector pursued by means of the highly polarized radiation of the electron capture into the K shell of naked xenon. In the following in two further experiments new values on the polarization of the electron capture into the K shell both of the naked and of the hydrogen-like uranium were performed.

  16. Photon-number-resolving SSPDs with system detection efficiency over 50% at telecom range

    Science.gov (United States)

    Zolotov, P.; Divochiy, A.; Vakhtomin, Yu.; Moshkova, M.; Morozov, P.; Seleznev, V.; Smirnov, K.

    2018-02-01

    We used technology of making high-efficiency superconducting single-photon detectors as a basis for improvement of photon-number-resolving devices. By adding optical cavity and using an improved NbN superconducting film, we enhanced previously reported system detection efficiency at telecom range for such detectors. Our results show that implementation of optical cavity helps to develop four-section device with quantum efficiency over 50% at 1.55 µm. Performed experimental studies of detecting multi-photon optical pulses showed irregularities over defining multi-photon through single-photon quantum efficiency.

  17. An online, energy-resolving beam profile detector for laser-driven proton beams

    Energy Technology Data Exchange (ETDEWEB)

    Metzkes, J.; Rehwald, M.; Obst, L.; Schramm, U. [Helmholtz-Zentrum Dresden–Rossendorf (HZDR), Bautzner Landstr. 400, 01328 Dresden (Germany); Technische Universität Dresden, 01062 Dresden (Germany); Zeil, K.; Kraft, S. D.; Sobiella, M.; Schlenvoigt, H.-P. [Helmholtz-Zentrum Dresden–Rossendorf (HZDR), Bautzner Landstr. 400, 01328 Dresden (Germany); Karsch, L. [OncoRay-National Center for Radiation Research in Oncology, Technische Universität Dresden, 01307 Dresden (Germany)

    2016-08-15

    In this paper, a scintillator-based online beam profile detector for the characterization of laser-driven proton beams is presented. Using a pixelated matrix with varying absorber thicknesses, the proton beam is spatially resolved in two dimensions and simultaneously energy-resolved. A thin plastic scintillator placed behind the absorber and read out by a CCD camera is used as the active detector material. The spatial detector resolution reaches down to ∼4 mm and the detector can resolve proton beam profiles for up to 9 proton threshold energies. With these detector design parameters, the spatial characteristics of the proton distribution and its cut-off energy can be analyzed online and on-shot under vacuum conditions. The paper discusses the detector design, its characterization and calibration at a conventional proton source, as well as the first detector application at a laser-driven proton source.

  18. A direct electron detector for time-resolved MeV electron microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Vecchione, T.; Denes, P.; Jobe, R. K.; Johnson, I. J.; Joseph, J. M.; Li, R. K.; Perazzo, A.; Shen, X.; Wang, X. J.; Weathersby, S. P.; Yang, J.; Zhang, D.

    2017-03-01

    The introduction of direct electron detectors enabled the structural biology revolution of cryogenic electron microscopy. Direct electron detectors are now expected to have a similarly dramatic impact on time-resolved MeV electron microscopy, particularly by enabling both spatial and temporal jitter correction. Here we report on the commissioning of a direct electron detector for time-resolved MeV electron microscopy. The direct electron detector demonstrated MeV single electron sensitivity and is capable of recording megapixel images at 180 Hz. The detector has a 15-bit dynamic range, better than 30-μmμm spatial resolution and less than 20 analogue-to-digital converter count RMS pixel noise. The unique capabilities of the direct electron detector and the data analysis required to take advantage of these capabilities are presented. The technical challenges associated with generating and processing large amounts of data are also discussed.

  19. Studying the potential of point detectors in time-resolved dose verification of dynamic radiotherapy

    DEFF Research Database (Denmark)

    Beierholm, Anders Ravnsborg; Behrens, C. F.; Andersen, Claus E.

    2015-01-01

    based on fiber-coupled plastic scintillator detectors was evaluated and compared with a Farmer-type ionization chamber and a small-volume ionization chamber. An important feature of scintillator detectors is that the sensitive volume of the detector can easily be scaled, and five scintillator detectors......-volume ionization chamber and the smallest scintillators. The time-resolved RapidArc dose profiles revealed volume-dependent discrepancies between scintillator and ionization chamber response, which confirmed that correction factors for ionization chambers in high temporal and spatial dose gradients are dominated...

  20. Resolving overlaping gammas in a modular neutrals detector

    International Nuclear Information System (INIS)

    Bulos, F.

    1975-01-01

    It is shown that in a segmented neutral detector the method of moments can be used to determine whether a connected region of energy deposit involving several modules contains one, two, or more γ's. Up to 2 γ's can be handled analytically to solve for their energy and position. Further it is shown that if the positions of the γ's are determined externally, then the method of moments can be used to solve the problem of more than 2 γ's analytically

  1. Primary Numbers Database for ATLAS Detector Description Parameters

    CERN Document Server

    Vaniachine, A; Malon, D; Nevski, P; Wenaus, T

    2003-01-01

    We present the design and the status of the database for detector description parameters in ATLAS experiment. The ATLAS Primary Numbers are the parameters defining the detector geometry and digitization in simulations, as well as certain reconstruction parameters. Since the detailed ATLAS detector description needs more than 10,000 such parameters, a preferred solution is to have a single verified source for all these data. The database stores the data dictionary for each parameter collection object, providing schema evolution support for object-based retrieval of parameters. The same Primary Numbers are served to many different clients accessing the database: the ATLAS software framework Athena, the Geant3 heritage framework Atlsim, the Geant4 developers framework FADS/Goofy, the generator of XML output for detector description, and several end-user clients for interactive data navigation, including web-based browsers and ROOT. The choice of the MySQL database product for the implementation provides addition...

  2. Studying the potential of point detectors in time-resolved dose verification of dynamic radiotherapy

    International Nuclear Information System (INIS)

    Beierholm, A.R.; Behrens, C.F.; Andersen, C.E.

    2015-01-01

    Modern megavoltage x-ray radiotherapy with high spatial and temporal dose gradients puts high demands on the entire delivery system, including not just the linear accelerator and the multi-leaf collimator, but also algorithms used for optimization and dose calculations, and detectors used for quality assurance and dose verification. In this context, traceable in-phantom dosimetry using a well-characterized point detector is often an important supplement to 2D-based quality assurance methods based on radiochromic film or detector arrays. In this study, an in-house developed dosimetry system based on fiber-coupled plastic scintillator detectors was evaluated and compared with a Farmer-type ionization chamber and a small-volume ionization chamber. An important feature of scintillator detectors is that the sensitive volume of the detector can easily be scaled, and five scintillator detectors of different scintillator length were thus employed to quantify volume averaging effects by direct measurement. The dosimetric evaluation comprised several complex-shape static fields as well as simplified dynamic deliveries using RapidArc, a volumetric-modulated arc therapy modality often used at the participating clinic. The static field experiments showed that the smallest scintillator detectors were in the best agreement with dose calculations, while needing the smallest volume averaging corrections. Concerning total dose measured during RapidArc, all detectors agreed with dose calculations within 1.1 ± 0.7% when positioned in regions of high homogenous dose. Larger differences were observed for high dose gradient and organ at risk locations, were differences between measured and calculated dose were as large as 8.0 ± 5.5%. The smallest differences were generally seen for the small-volume ionization chamber and the smallest scintillators. The time-resolved RapidArc dose profiles revealed volume-dependent discrepancies between scintillator and ionization chamber response

  3. Quantitative material decomposition using spectral computed tomography with an energy-resolved photon-counting detector

    International Nuclear Information System (INIS)

    Lee, Seungwan; Choi, Yu-Na; Kim, Hee-Joung

    2014-01-01

    Dual-energy computed tomography (CT) techniques have been used to decompose materials and characterize tissues according to their physical and chemical compositions. However, these techniques are hampered by the limitations of conventional x-ray detectors operated in charge integrating mode. Energy-resolved photon-counting detectors provide spectral information from polychromatic x-rays using multiple energy thresholds. These detectors allow simultaneous acquisition of data in different energy ranges without spectral overlap, resulting in more efficient material decomposition and quantification for dual-energy CT. In this study, a pre-reconstruction dual-energy CT technique based on volume conservation was proposed for three-material decomposition. The technique was combined with iterative reconstruction algorithms by using a ray-driven projector in order to improve the quality of decomposition images and reduce radiation dose. A spectral CT system equipped with a CZT-based photon-counting detector was used to implement the proposed dual-energy CT technique. We obtained dual-energy images of calibration and three-material phantoms consisting of low atomic number materials from the optimal energy bins determined by Monte Carlo simulations. The material decomposition process was accomplished by both the proposed and post-reconstruction dual-energy CT techniques. Linear regression and normalized root-mean-square error (NRMSE) analyses were performed to evaluate the quantitative accuracy of decomposition images. The calibration accuracy of the proposed dual-energy CT technique was higher than that of the post-reconstruction dual-energy CT technique, with fitted slopes of 0.97–1.01 and NRMSEs of 0.20–4.50% for all basis materials. In the three-material phantom study, the proposed dual-energy CT technique decreased the NRMSEs of measured volume fractions by factors of 0.17–0.28 compared to the post-reconstruction dual-energy CT technique. It was concluded that the

  4. Parameters affecting temporal resolution of Time Resolved Integrative Optical Neutron Detector (TRION)

    International Nuclear Information System (INIS)

    Mor, I; Vartsky, D; Bar, D; Feldman, G; Goldberg, M B; Brandis, M; Dangendorf, V; Tittelmeier, K; Bromberger, B; Weierganz, M

    2013-01-01

    The Time-Resolved Integrative Optical Neutron (TRION) detector was developed for Fast Neutron Resonance Radiography (FNRR), a fast-neutron transmission imaging method that exploits characteristic energy-variations of the total scattering cross-section in the E n = 1–10 MeV range to detect specific elements within a radiographed object. As opposed to classical event-counting time of flight (ECTOF), it integrates the detector signal during a well-defined neutron Time of Flight window corresponding to a pre-selected energy bin, e.g., the energy-interval spanning a cross-section resonance of an element such as C, O and N. The integrative characteristic of the detector permits loss-free operation at very intense, pulsed neutron fluxes, at a cost however, of recorded temporal resolution degradation This work presents a theoretical and experimental evaluation of detector related parameters which affect temporal resolution of the TRION system

  5. New approaches for a time- and position-resolved detector for positron annihilation spectroscopy at PLEPS

    Energy Technology Data Exchange (ETDEWEB)

    Ackermann, Ulrich; Egger, Werner; Sperr, Peter; Loewe, Benjamin; Ravelli, Luca; Koegel, Gottfried; Dollinger, Guenther [Universitaet der Bundeswehr Muenchen, LRT2 (Germany); Jagutzki, Ottmar [Universitaet Frankfurt, RoentDek GmbH (Germany)

    2013-07-01

    The pulsed low energy positron system PLEPS at NEPOMUC at the FRM II is a tool for depth resolved positron lifetime measurements. Besides positron lifetime measurements 2D-AMOC (two dimensional age momentum correlation) experiments are also possible. 2D-AMOC provides in coincidence the lifetime of the positron and the longitudinal momentum distribution of the annihilating electron. It would be of great scientific concern to measure simultaneously the entire 3D-momentum distribution of the annihilating electron and the corresponding lifetime of the positron (4D-AMOC). To perform 4D-AMOC measurements, a time and spatially resolving detector with a time resolution of about 100 ps (FWHM) and a spatial resolution of circa 2 mm over an area of about 12 cm{sup 2} is required in coincidence with a pixelated Ge-detector and currently under development at our institute. It is intended to use a MCP-based UV-light detector with two MCP-stages coupled to a BaF{sub 2} scintillator. To achieve the spatial resolution the centroid information of the photoelectron-cloud is detected with a position sensitive anode installed outside the housing of the MCP detector. As an alternative to a MCP-based detector, silicon photomultipliers are also envisaged.

  6. The Dosepix detector—an energy-resolving photon-counting pixel detector for spectrometric measurements

    CERN Document Server

    Zang, A; Ballabriga, R; Bisello, F; Campbell, M; Celi, J C; Fauler, A; Fiederle, M; Jensch, M; Kochanski, N; Llopart, X; Michel, N; Mollenhauer, U; Ritter, I; Tennert, F; Wölfel, S; Wong, W; Michel, T

    2015-01-01

    The Dosepix detector is a hybrid photon-counting pixel detector based on ideas of the Medipix and Timepix detector family. 1 mm thick cadmium telluride and 300 μm thick silicon were used as sensor material. The pixel matrix of the Dosepix consists of 16 x 16 square pixels with 12 rows of (200 μm)2 and 4 rows of (55 μm)2 sensitive area for the silicon sensor layer and 16 rows of pixels with 220 μm pixel pitch for CdTe. Besides digital energy integration and photon-counting mode, a novel concept of energy binning is included in the pixel electronics, allowing energy-resolved measurements in 16 energy bins within one acquisition. The possibilities of this detector concept range from applications in personal dosimetry and energy-resolved imaging to quality assurance of medical X-ray sources by analysis of the emitted photon spectrum. In this contribution the Dosepix detector, its response to X-rays as well as spectrum measurements with Si and CdTe sensor layer are presented. Furthermore, a first evaluation wa...

  7. Preliminary evaluation of a novel energy-resolved photon-counting gamma ray detector.

    Science.gov (United States)

    Meng, L-J; Tan, J W; Spartiotis, K; Schulman, T

    2009-06-11

    In this paper, we present the design and preliminary performance evaluation of a novel energy-resolved photon-counting (ERPC) detector for gamma ray imaging applications. The prototype ERPC detector has an active area of 4.4 cm × 4.4 cm, which is pixelated into 128 × 128 square pixels with a pitch size of 350 µm × 350µm. The current detector consists of multiple detector hybrids, each with a CdTe crystal of 1.1 cm × 2.2 cm × 1 mm, bump-bonded onto a custom-designed application-specific integrated circuit (ASIC). The ERPC ASIC has 2048 readout channels arranged in a 32 × 64 array. Each channel is equipped with pre- and shaping-amplifiers, a discriminator, peak/hold circuitry and an analog-to-digital converter (ADC) for digitizing the signal amplitude. In order to compensate for the pixel-to-pixel variation, two 8-bit digital-to-analog converters (DACs) are implemented into each channel for tuning the gain and offset. The ERPC detector is designed to offer a high spatial resolution, a wide dynamic range of 12-200 keV and a good energy resolution of 3-4 keV. The hybrid detector configuration provides a flexible detection area that can be easily tailored for different imaging applications. The intrinsic performance of a prototype ERPC detector was evaluated with various gamma ray sources, and the results are presented.

  8. Versatile, reprogrammable area pixel array detector for time-resolved synchrotron x-ray applications

    Energy Technology Data Exchange (ETDEWEB)

    Gruner, Sol [Cornell Univ., Ithaca, NY (United States)

    2010-05-01

    The final technical report for DOE grant DE-SC0004079 is presented. The goal of the grant was to perform research, development and application of novel imaging x-ray detectors so as to effectively utilize the high intensity and brightness of the national synchrotron radiation facilities to enable previously unfeasible time-resolved x-ray research. The report summarizes the development of the resultant imaging x-ray detectors. Two types of detector platforms were developed: The first is a detector platform (called a Mixed-Mode Pixel Array Detector, or MM-PAD) that can image continuously at over a thousand images per second while maintaining high efficiency for wide dynamic range signals ranging from 1 to hundreds of millions of x-rays per pixel per image. Research on an even higher dynamic range variant is also described. The second detector platform (called the Keck Pixel Array Detector) is capable of acquiring a burst of x-ray images at a rate of millions of images per second.

  9. Development of a Schottky CdTe Medipix3RX hybrid photon counting detector with spatial and energy resolving capabilities

    Energy Technology Data Exchange (ETDEWEB)

    Gimenez, E.N., E-mail: Eva.Gimenez@diamond.ac.uk [Diamond Light Source, Harwell Campus, Oxforshire OX11 0DE (United Kingdom); Astromskas, V. [University of Surrey (United Kingdom); Horswell, I.; Omar, D.; Spiers, J.; Tartoni, N. [Diamond Light Source, Harwell Campus, Oxforshire OX11 0DE (United Kingdom)

    2016-07-11

    A multichip CdTe-Medipix3RX detector system was developed in order to bring the advantages of photon-counting detectors to applications in the hard X-ray range of energies. The detector head consisted of 2×2 Medipix3RX ASICs bump-bonded to a 28 mm×28 mm e{sup −} collection Schottky contact CdTe sensor. Schottky CdTe sensors undergo performance degrading polarization which increases with temperature, flux and the longer the HV is applied. Keeping the temperature stable and periodically refreshing the high voltage bias supply was used to minimize the polarization and achieve a stable and reproducible detector response. This leads to good quality images and successful results on the energy resolving capabilities of the system. - Highlights: • A high atomic number (CdTe sensor based) photon-counting detector was developed. • Polarization effects affected the image were minimized by regularly refreshing the bias voltage and stabilizing the temperature. • Good spatial resolution and image quality was achieved following this procedure.

  10. Compton polarimetry with position-resolving X-ray detectors; Compton-Polarimetrie mit ortsaufloesenden Roentgendetektoren

    Energy Technology Data Exchange (ETDEWEB)

    Hess, Sebastian

    2010-02-15

    In the present thesis the prototype of a novel position-resolving and multi-hit able 2D Si(Li) strip detector is characterized, the planar detector crystal of which is simultaneously applied both as scatterer and as absorber. In the framework of this thesis the Si(Li) polarimeter could be applied in different experiments on the radiative electron capture and on the characteristic radiation at the experimental storage ring of the GSI. The characterization of the detector pursued by means of the highly polarized radiation of the electron capture into the K shell of naked xenon. In the following in two further experiments new values on the polarization of the electron capture into the K shell both of the naked and of the hydrogen-like uranium were performed.

  11. A time resolving data acquisition system for multiple high-resolution position sensitive detectors

    International Nuclear Information System (INIS)

    Dimmler, D.G.

    1988-01-01

    An advanced time resolving data collection system for use in neutron and x-ray spectrometry has been implemented and put into routine operation. The system collects data from high-resolution position-sensitive area detectors with a maximum cumulative rate of 10/sup 6/ events per second. The events are sorted, in real-time, into many time-slice arrays. A programmable timing control unit allows for a wide choice of time sequences and time-slice array sizes. The shortest dwell time on a slice may be below 1 ms and the delay to switch between slices is zero

  12. 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

  13. Time-resolved triton burnup measurement using the scintillating fiber detector in the Large Helical Device

    Science.gov (United States)

    Ogawa, K.; Isobe, M.; Nishitani, T.; Murakami, S.; Seki, R.; Nakata, M.; Takada, E.; Kawase, H.; Pu, N.; LHD Experiment Group

    2018-03-01

    Time-resolved measurement of triton burnup is performed with a scintillating fiber detector system in the deuterium operation of the large helical device. The scintillating fiber detector system is composed of the detector head consisting of 109 scintillating fibers having a diameter of 1 mm and a length of 100 mm embedded in the aluminum substrate, the magnetic registrant photomultiplier tube, and the data acquisition system equipped with 1 GHz sampling rate analogies to digital converter and the field programmable gate array. The discrimination level of 150 mV was set to extract the pulse signal induced by 14 MeV neutrons according to the pulse height spectra obtained in the experiment. The decay time of 14 MeV neutron emission rate after neutral beam is turned off measured by the scintillating fiber detector. The decay time is consistent with the decay time of total neutron emission rate corresponding to the 14 MeV neutrons measured by the neutron flux monitor as expected. Evaluation of the diffusion coefficient is conducted using a simple classical slowing-down model FBURN code. It is found that the diffusion coefficient of triton is evaluated to be less than 0.2 m2 s-1.

  14. Resolving the neutrino mass hierarchy and CP degeneracy by two identical detectors with different baselines

    International Nuclear Information System (INIS)

    Ishitsuka, Masaki; Kajita, Takaaki; Minakata, Hisakazu; Nunokawa, Hiroshi

    2005-01-01

    We explore the possibility of the simultaneous determination of neutrino mass hierarchy and the CP violating phase by using two identical detectors placed at different baseline distances. We focus on a possible experimental setup using a neutrino beam from the J-PARC facility in Japan with a beam power of 4 MW and megaton (Mton)-class water Cherenkov detectors, one placed in Kamioka and the other somewhere in Korea. We demonstrate, under reasonable assumptions of systematic uncertainties, that the two-detector complex with each fiducial volume of 0.27 Mton has a potential of resolving the neutrino mass hierarchy up to sin 2 2θ 13 >0.03 (0.055) at 2σ (3σ) C.L. for any values of δ and at the same time has the sensitivity to CP violation by 4+4 years running of ν e and ν e appearance measurement. The significantly enhanced sensitivity is due to clean detection of the modulation of the neutrino energy spectrum, which is enabled by the cancellation of systematic uncertainties between two identical detectors which receive the neutrino beam with the same energy spectrum in the absence of oscillations

  15. 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.

  16. Algorithms for spectral calibration of energy-resolving small-pixel detectors

    International Nuclear Information System (INIS)

    Scuffham, J; Veale, M C; Wilson, M D; Seller, P

    2013-01-01

    Small pixel Cd(Zn)Te detectors often suffer from inter-pixel variations in gain, resulting in shifts in the individual energy spectra. These gain variations are mainly caused by inclusions and defects within the crystal structure, which affect the charge transport within the material causing a decrease in the signal pulse height. In imaging applications, spectra are commonly integrated over a particular peak of interest. This means that the individual pixels must be accurately calibrated to ensure that the same portion of the spectrum is integrated in every pixel. The development of large-area detectors with fine pixel pitch necessitates automated algorithms for this spectral calibration, due to the very large number of pixels. Algorithms for automatic spectral calibration require accurate determination of characteristic x-ray or photopeak positions on a pixelwise basis. In this study, we compare two peak searching spectral calibration algorithms for a small-pixel CdTe detector in gamma spectroscopic imaging. The first algorithm uses rigid search ranges to identify peaks in each pixel spectrum, based on the average peak positions across all pixels. The second algorithm scales the search ranges on the basis of the position of the highest-energy peak relative to the average across all pixels. In test spectra acquired with Tc-99m, we found that the rigid search algorithm failed to correctly identify the target calibraton peaks in up to 4% of pixels. In contrast, the scaled search algorithm failed in only 0.16% of pixels. Failures in the scaled search algorithm were attributed to the presence of noise events above the main photopeak, and possible non-linearities in the spectral response in a small number of pixels. We conclude that a peak searching algorithm based on scaling known peak spacings is simple to implement and performs well for the spectral calibration of pixellated radiation detectors

  17. Picosecond time-resolved laser pump/X-ray probe experiments using a gated single-photon-counting area detector

    DEFF Research Database (Denmark)

    Ejdrup, T.; Lemke, H.T.; Haldrup, Martin Kristoffer

    2009-01-01

    The recent developments in X-ray detectors have opened new possibilities in the area of time-resolved pump/probe X-ray experiments; this article presents the novel use of a PILATUS detector to achieve X-ray pulse duration limited time-resolution at the Advanced Photon Source (APS), USA...... limited time-resolution of 60 ps using the gated PILATUS detector. This is the first demonstration of X-ray pulse duration limited data recorded using an area detector without the use of a mechanical chopper array at the beamline........ The capability of the gated PILATUS detector to selectively detect the signal from a given X-ray pulse in 24 bunch mode at the APS storage ring is demonstrated. A test experiment performed on polycrystalline organic thin films of [alpha]-perylene illustrates the possibility of reaching an X-ray pulse duration...

  18. A scintillator-based online detector for the angularly resolved measurement of laser-accelerated proton spectra

    International Nuclear Information System (INIS)

    Metzkes, J.; Kraft, S. D.; Sobiella, M.; Stiller, N.; Zeil, K.; Schramm, U.; Karsch, L.; Schürer, M.; Pawelke, J.; Richter, C.

    2012-01-01

    In recent years, a new generation of high repetition rate (∼10 Hz), high power (∼100 TW) laser systems has stimulated intense research on laser-driven sources for fast protons. Considering experimental instrumentation, this development requires online diagnostics for protons to be added to the established offline detection tools such as solid state track detectors or radiochromic films. In this article, we present the design and characterization of a scintillator-based online detector that gives access to the angularly resolved proton distribution along one spatial dimension and resolves 10 different proton energy ranges. Conceived as an online detector for key parameters in laser-proton acceleration, such as the maximum proton energy and the angular distribution, the detector features a spatial resolution of ∼1.3 mm and a spectral resolution better than 1.5 MeV for a maximum proton energy above 12 MeV in the current design. Regarding its areas of application, we consider the detector a useful complement to radiochromic films and Thomson parabola spectrometers, capable to give immediate feedback on the experimental performance. The detector was characterized at an electrostatic Van de Graaff tandetron accelerator and tested in a laser-proton acceleration experiment, proving its suitability as a diagnostic device for laser-accelerated protons.

  19. A scintillator-based online detector for the angularly resolved measurement of laser-accelerated proton spectra.

    Science.gov (United States)

    Metzkes, J; Karsch, L; Kraft, S D; Pawelke, J; Richter, C; Schürer, M; Sobiella, M; Stiller, N; Zeil, K; Schramm, U

    2012-12-01

    In recent years, a new generation of high repetition rate (~10 Hz), high power (~100 TW) laser systems has stimulated intense research on laser-driven sources for fast protons. Considering experimental instrumentation, this development requires online diagnostics for protons to be added to the established offline detection tools such as solid state track detectors or radiochromic films. In this article, we present the design and characterization of a scintillator-based online detector that gives access to the angularly resolved proton distribution along one spatial dimension and resolves 10 different proton energy ranges. Conceived as an online detector for key parameters in laser-proton acceleration, such as the maximum proton energy and the angular distribution, the detector features a spatial resolution of ~1.3 mm and a spectral resolution better than 1.5 MeV for a maximum proton energy above 12 MeV in the current design. Regarding its areas of application, we consider the detector a useful complement to radiochromic films and Thomson parabola spectrometers, capable to give immediate feedback on the experimental performance. The detector was characterized at an electrostatic Van de Graaff tandetron accelerator and tested in a laser-proton acceleration experiment, proving its suitability as a diagnostic device for laser-accelerated protons.

  20. Revealing of photon-number splitting attack on quantum key distribution system by photon-number resolving devices

    International Nuclear Information System (INIS)

    Gaidash, A A; Egorov, V I; Gleim, A V

    2016-01-01

    Quantum cryptography allows distributing secure keys between two users so that any performed eavesdropping attempt would be immediately discovered. However, in practice an eavesdropper can obtain key information from multi-photon states when attenuated laser radiation is used as a source of quantum states. In order to prevent actions of an eavesdropper, it is generally suggested to implement special cryptographic protocols, like decoy states or SARG04. In this paper, we describe an alternative method based on monitoring photon number statistics after detection. We provide a useful rule of thumb to estimate approximate order of difference of expected distribution and distribution in case of attack. Formula for calculating a minimum value of total pulses or time-gaps to resolve attack is shown. Also formulas for actual fraction of raw key known to Eve were derived. This method can therefore be used with any system and even combining with mentioned special protocols. (paper)

  1. Use of Resolving Equation to Define the Lower Critical Reynolds Number

    Directory of Open Access Journals (Sweden)

    Alexander A. Solovyev

    2014-09-01

    Full Text Available Although the issue of streams with non-crossing trajectories of particle motions ranging from chaotic, random with irregular current lines, has been given a lot of attention, it still remains unresolved. The study features a relevant issue for hydromechanics, which is precise values determination of the Lower Critical Reynolds Number. It is suggested to put forward an updated approach to the use of energetic analysis for analytical calculation of the Reynolds Resolving Equation. The assessment of transition to mean motion from pulsation to the direction of laminar flows was fulfilled.

  2. Quantum state engineering, purification, and number-resolved photon detection with high-finesse optical cavities

    DEFF Research Database (Denmark)

    Nielsen, Anne E. B.; Muschik, Christine A.; Giedke, Geza

    2010-01-01

    We propose and analyze a multifunctional setup consisting of high-finesse optical cavities, beam splitters, and phase shifters. The basic scheme projects arbitrary photonic two-mode input states onto the subspace spanned by the product of Fock states |n>|n> with n=0,1,2,.... This protocol does no...... is especially attractive as a generalization to many modes allows for distribution and purification of entanglement in networks. In an alternative working mode, the setup allows for quantum nondemolition number resolved photodetection in the optical domain....

  3. Static and time-resolved 10-1000 keV x-ray imaging detector options for NIF

    International Nuclear Information System (INIS)

    Landen, O.L.; Bell, P.M.; McDonald, J.W.; Park, H.-S.; Weber, F.; Moody, J.D.; Lowry, M.E.; Stewart, R.E.

    2004-01-01

    High energy (>10 keV) x-ray self-emission imaging and radiography will be essential components of many NIF high energy density physics experiments. In preparation for such experiments, we have evaluated the pros and cons of various static [x-ray film, bare charge-coupled device (CCD), and scintillator + CCD] and time-resolved (streaked and gated) 10-1000 keV detectors

  4. Disentangling detector data in XFEL studies of temporally resolved solution state chemistry

    DEFF Research Database (Denmark)

    Brandt van Driel, Tim; Kjær, Kasper Skov; Biasin, Elisa

    2015-01-01

    With the arrival of X-ray Free Electron Lasers (XFELs), 2D area detectors with a large dynamic range for detection of hard X-rays with fast readout rates are required for many types of experiments. Extracting the desired information from these detectors has been challenging due to unpredicted flu...

  5. A development of time-resolved emulsion detector by multi-stage shifter

    International Nuclear Information System (INIS)

    Takahashi, Satoru; Aoki, Shigeki

    2017-01-01

    Nuclear emulsion is a powerful tracking device that can record the three-dimensional trajectory of charged particles within 1 μm spatial resolution. We are promoting GRAINE project which is 10 MeV-100 GeV cosmic γ-ray observations with a precise (0.08deg at 1-2 GeV) and polarization-sensitive large-aperture-area (∼10 m 2 ) emulsion telescope by repeating long duration balloon flights. We are developing multi-stage shifter which allows us to give a timing information to emulsion tracks with ∼seconds or below. The multi-stage shifter opened feasibilities of precise cosmic γ-ray observations, GRAINE, as well as precise measurements of ν-N interactions, J-PARC T60. ∼Millisecond time resolution in a balloon-borne experiment, ∼second time resolution for 126.7 days in an accelerator ν experiment and ∼10 6 time-resolved numbers are being achieved. New model of multi-stage shifter is also being developed for future experiments. (author)

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

    International Nuclear Information System (INIS)

    Kienlin, A. von.

    1994-01-01

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

  7. Multichannel, time-resolved picosecond laser ultrasound imaging and spectroscopy with custom complementary metal-oxide-semiconductor detector

    International Nuclear Information System (INIS)

    Smith, Richard J.; Light, Roger A.; Johnston, Nicholas S.; Pitter, Mark C.; Somekh, Mike G.; Sharples, Steve D.

    2010-01-01

    This paper presents a multichannel, time-resolved picosecond laser ultrasound system that uses a custom complementary metal-oxide-semiconductor linear array detector. This novel sensor allows parallel phase-sensitive detection of very low contrast modulated signals with performance in each channel comparable to that of a discrete photodiode and a lock-in amplifier. Application of the instrument is demonstrated by parallelizing spatial measurements to produce two-dimensional thickness maps on a layered sample, and spectroscopic parallelization is demonstrated by presenting the measured Brillouin oscillations from a gallium arsenide wafer. This paper demonstrates the significant advantages of our approach to pump probe systems, especially picosecond ultrasonics.

  8. Multichannel, time-resolved picosecond laser ultrasound imaging and spectroscopy with custom complementary metal-oxide-semiconductor detector

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Richard J.; Light, Roger A.; Johnston, Nicholas S.; Pitter, Mark C.; Somekh, Mike G. [Institute of Biophysics, Imaging and Optical Science, University of Nottingham, Nottinghamshire NG7 2RD (United Kingdom); Sharples, Steve D. [Applied Optics Group, Electrical Systems and Optics Research Division, University of Nottingham, Nottinghamshire NG7 2RD (United Kingdom)

    2010-02-15

    This paper presents a multichannel, time-resolved picosecond laser ultrasound system that uses a custom complementary metal-oxide-semiconductor linear array detector. This novel sensor allows parallel phase-sensitive detection of very low contrast modulated signals with performance in each channel comparable to that of a discrete photodiode and a lock-in amplifier. Application of the instrument is demonstrated by parallelizing spatial measurements to produce two-dimensional thickness maps on a layered sample, and spectroscopic parallelization is demonstrated by presenting the measured Brillouin oscillations from a gallium arsenide wafer. This paper demonstrates the significant advantages of our approach to pump probe systems, especially picosecond ultrasonics.

  9. Timepix3 as X-ray detector for time resolved synchrotron experiments

    Energy Technology Data Exchange (ETDEWEB)

    Yousef, Hazem, E-mail: hazem.yousef@diamond.ac.uk; Crevatin, Giulio; Gimenez, Eva N.; Horswell, Ian; Omar, David; Tartoni, Nicola

    2017-02-11

    The Timepix3 ASIC can be used very effectively for time resolved experiments at synchrotron facilities. We have carried out characterizations with the synchrotron beam in order to determine the time resolution and other characteristics such as the energy resolution, charge sharing and signals overlapping. The best time resolution achieved is 19 ns FWHM for 12 keV photons and 350 V bias voltage. The time resolution shows dependency on the photon energy as well as on the chip and acquisition parameters. - Highlights: • An estimate time resolution of the Timepix3 is produced based on the arrival time. • At high resolution, the time structure of the DLS synchrotron beam is resolved. • The arrival time information improves combining the charge split events. • The results enable performing a wide range of time resolved experiments.

  10. Timepix3 as X-ray detector for time resolved synchrotron experiments

    International Nuclear Information System (INIS)

    Yousef, Hazem; Crevatin, Giulio; Gimenez, Eva N.; Horswell, Ian; Omar, David; Tartoni, Nicola

    2017-01-01

    The Timepix3 ASIC can be used very effectively for time resolved experiments at synchrotron facilities. We have carried out characterizations with the synchrotron beam in order to determine the time resolution and other characteristics such as the energy resolution, charge sharing and signals overlapping. The best time resolution achieved is 19 ns FWHM for 12 keV photons and 350 V bias voltage. The time resolution shows dependency on the photon energy as well as on the chip and acquisition parameters. - Highlights: • An estimate time resolution of the Timepix3 is produced based on the arrival time. • At high resolution, the time structure of the DLS synchrotron beam is resolved. • The arrival time information improves combining the charge split events. • The results enable performing a wide range of time resolved experiments.

  11. 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

  12. Time-Resolved Diffuse Optical Spectroscopy and Imaging Using Solid-State Detectors: Characteristics, Present Status, and Research Challenges.

    Science.gov (United States)

    Alayed, Mrwan; Deen, M Jamal

    2017-09-14

    Diffuse optical spectroscopy (DOS) and diffuse optical imaging (DOI) are emerging non-invasive imaging modalities that have wide spread potential applications in many fields, particularly for structural and functional imaging in medicine. In this article, we review time-resolved diffuse optical imaging (TR-DOI) systems using solid-state detectors with a special focus on Single-Photon Avalanche Diodes (SPADs) and Silicon Photomultipliers (SiPMs). These TR-DOI systems can be categorized into two types based on the operation mode of the detector (free-running or time-gated). For the TR-DOI prototypes, the physical concepts, main components, figures-of-merit of detectors, and evaluation parameters are described. The performance of TR-DOI prototypes is evaluated according to the parameters used in common protocols to test DOI systems particularly basic instrumental performance (BIP). In addition, the potential features of SPADs and SiPMs to improve TR-DOI systems and expand their applications in the foreseeable future are discussed. Lastly, research challenges and future developments for TR-DOI are discussed for each component in the prototype separately and also for the entire system.

  13. How comparable are size-resolved particle number concentrations from different instruments?

    Science.gov (United States)

    Hornsby, K. E.; Pryor, S. C.

    2012-12-01

    The need for comparability of particle size resolved measurements originates from multiple drivers including: (i) Recent suggestions that air quality standards for particulate matter should migrate from being mass-based to incorporating number concentrations. This move would necessarily be predicated on measurement comparability which is absolutely critical to compliance determination. (ii) The need to quantify and diagnose causes of variability in nucleation and growth rates in nano-particle experiments conducted in different locations. (iii) Epidemiological research designed to identify key parameters in human health responses to fine particle exposure. Here we present results from a detailed controlled laboratory instrument inter-comparison experiment designed to investigate data comparability in the size range of 2.01-523.3 nm across a range of particle composition, modal diameter and absolute concentration. Particle size distributions were generated using a TSI model 3940 Aerosol Generation System (AGS) diluted using zero air, and sampled using four TSI Scanning Mobility Particle Spectrometer (SMPS) configurations and a TSI model 3091 Fast Mobility Particle Sizer (FMPS). The SMPS configurations used two Electrostatic Classifiers (EC) (model 3080) attached to either a Long DMA (LDMA) (model 3081) or a Nano DMA (NDMA) (model 3085) plumbed to either a TSI model 3025A Butanol Condensed Particle Counting (CPC) or a TSI model 3788 Water CPC. All four systems were run using both high and low flow conditions, and were operated with both the internal diffusion loss and multiple charge corrections turned on. The particle compositions tested were sodium chloride, ammonium nitrate and olive oil diluted in ethanol. Particles of all three were generated at three peak concentration levels (spanning the range observed at our experimental site), and three modal particle diameters. Experimental conditions were maintained for a period of 20 minutes to ensure experimental

  14. Angle-resolved ion TOF spectrometer with a position sensitive detector

    Energy Technology Data Exchange (ETDEWEB)

    Saito, Norio [Electrotechnical Lab., Tsukuba, Ibaraki (Japan); Heiser, F; Wieliczec, K; Becker, U

    1996-07-01

    A angle-resolved ion time-of-flight mass spectrometer with a position sensitive anode has been investigated. Performance of this spectrometer has been demonstrated by measuring an angular distribution of a fragment ion pair, C{sup +} + O{sup +}, from CO at the photon energy of 287.4 eV. The obtained angular distribution is very close to the theoretically expected one. (author)

  15. A homodyne detector integrated onto a photonic chip for measuring quantum states and generating random numbers

    Science.gov (United States)

    Raffaelli, Francesco; Ferranti, Giacomo; Mahler, Dylan H.; Sibson, Philip; Kennard, Jake E.; Santamato, Alberto; Sinclair, Gary; Bonneau, Damien; Thompson, Mark G.; Matthews, Jonathan C. F.

    2018-04-01

    Optical homodyne detection has found use as a characterisation tool in a range of quantum technologies. So far implementations have been limited to bulk optics. Here we present the optical integration of a homodyne detector onto a silicon photonics chip. The resulting device operates at high speed, up 150 MHz, it is compact and it operates with low noise, quantified with 11 dB clearance between shot noise and electronic noise. We perform on-chip quantum tomography of coherent states with the detector and show that it meets the requirements for characterising more general quantum states of light. We also show that the detector is able to produce quantum random numbers at a rate of 1.2 Gbps, by measuring the vacuum state of the electromagnetic field and applying off-line post processing. The produced random numbers pass all the statistical tests provided by the NIST test suite.

  16. Total and size-resolved particle number and black carbon concentrations in urban areas near Schiphol airport (the Netherlands)

    NARCIS (Netherlands)

    Keuken, M.P.; Moerman, M.; Zandveld, P.; Henzing, J.S.; Hoek, G.

    2015-01-01

    The presence of black carbon, and size-resolved and total particle number concentrations (PNC) were investigated in the vicinity of Schiphol airport in the Netherlands, the fourth busiest airport in Europe. Continuous measurements were conducted between March and May 2014at Adamse Bos, located 7km

  17. Size-resolved particle number emission patterns under real-world driving conditions using positive matrix factorization

    NARCIS (Netherlands)

    Domínguez-Sáez, A.; Viana, M.; Barrios, C.C.; Rubio, J.R.; Amato, F.; Pujadas, M.; Querol, X.

    2012-01-01

    A novel on-board system was tested to characterize size-resolved particle number emission patterns under real-world driving conditions, running in a EURO4 diesel vehicle and in a typical urban circuit in Madrid (Spain). Emission profiles were determined as a function of driving conditions. Source

  18. Velocity-Resolved LES (VR-LES) technique for simulating turbulent transport of high Schmidt number passive scalars

    Science.gov (United States)

    Verma, Siddhartha; Blanquart, Guillaume; P. K. Yeung Collaboration

    2011-11-01

    Accurate simulation of high Schmidt number scalar transport in turbulent flows is essential to studying pollutant dispersion, weather, and several oceanic phenomena. Batchelor's theory governs scalar transport in such flows, but requires further validation at high Schmidt and high Reynolds numbers. To this end, we use a new approach with the velocity field fully resolved, but the scalar field only partially resolved. The grid used is fine enough to resolve scales up to the viscous-convective subrange where the decaying slope of the scalar spectrum becomes constant. This places the cutoff wavenumber between the Kolmogorov scale and the Batchelor scale. The subgrid scale terms, which affect transport at the supergrid scales, are modeled under the assumption that velocity fluctuations are negligible beyond this cutoff wavenumber. To ascertain the validity of this technique, we performed a-priori testing on existing DNS data. This Velocity-Resolved LES (VR-LES) technique significantly reduces the computational cost of turbulent simulations of high Schmidt number scalars, and yet provides valuable information of the scalar spectrum in the viscous-convective subrange.

  19. Application of charge coupled devices as spatially-resolved detectors for X-ray spectrograph

    Energy Technology Data Exchange (ETDEWEB)

    Attelan-Langlet, S; Etlicher, B [Ecole Polytechnique, Palaiseau (France); Mishenskij, V O; Papazyan, Yu V; Smirnov, V P; Volkov, G S; Zajtsev, V I [Inst. for Thermonuclear and Innovation Investigations, Troitsk (Russian Federation)

    1997-12-31

    An X-ray crystal spectrograph which contains a CCD linear array as the position-sensitive detector is described. Radiation detection is performed directly onto CCD. The spectrograph has a limit of sensitivity at about 2 J/(A.ster), spectral resolution about 1000 and dynamic range 100-120. The device operates on-line with IBM-PC based control system. Software provides all data acquisition and treatment. Output spectra are presented in absolute units. The device was used during composite Z-pinch experiments at pulse-power installations ``Angara-5-1`` (TRINITI, Troitsk, Russia) and ``GAEL`` (Ecole Polytechnique, Palaiseau, France). Currently the spectrograph is included in the set of diagnostics of the ``Angara-5-1`` facility. Some of the spectra obtained are presented and discussed. (author). 4 figs., 9 refs.

  20. Determination of seasonal, diurnal, and height resolved average number concentration in a pollution impacted rural continental location

    Science.gov (United States)

    Bullard, Robert L.; Stanier, Charles O.; Ogren, John A.; Sheridan, Patrick J.

    2013-05-01

    The impact of aerosols on Earth's radiation balance and the associated climate forcing effects of aerosols represent significant uncertainties in assessment reports. The main source of ultrafine aerosols in the atmosphere is the nucleation and subsequent growth of gas phase aerosol precursors into liquid or solid phase particles. Long term records of aerosol number, nucleation event frequency, and vertical profiles of number concentration are rare. The data record from multiagency monitoring assets at Bondville, IL can contribute important information on long term and vertically resolved patterns. Although particle number size distribution data are only occasionally available at Bondville, highly time-resolved particle number concentration data have been measured for nearly twenty years by the NOAA ESRL Global Monitoring Division. Furthermore, vertically-resolved aerosol counts and other aerosol physical parameters are available from more than 300 flights of the NOAA Airborne Aerosol Observatory (AAO). These data sources are used to better understand the seasonal, diurnal, and vertical variation and trends in atmospheric aerosols. The highest peaks in condensation nuclei greater than 14 nm occur during the spring months (May, April) with slightly lower peaks during the fall months (September, October). The diurnal pattern of aerosol number has a midday peak and the timing of the peak has seasonal patterns (earlier during warm months and later during colder months). The seasonal and diurnal patterns of high particle number peaks correspond to seasons and times of day associated with low aerosol mass and surface area. Average vertical profiles show a nearly monotonic decrease with altitude in all months, and with peak magnitudes occurring in the spring and fall. Individual flight tracks show evidence of plumes (i.e., enhanced aerosol number is limited to a small altitude range, is not homogeneous horizontally, or both) as well as periods with enhanced particle number

  1. Improvement of single detector proton radiography by incorporating intensity of time-resolved dose rate functions

    Science.gov (United States)

    Zhang, Rongxiao; Jee, Kyung-Wook; Cascio, Ethan; Sharp, Gregory C.; Flanz, Jacob B.; Lu, Hsiao-Ming

    2018-01-01

    Proton radiography, which images patients with the same type of particles as those with which they are to be treated, is a promising approach to image guidance and water equivalent path length (WEPL) verification in proton radiation therapy. We have shown recently that proton radiographs could be obtained by measuring time-resolved dose rate functions (DRFs) using an x-ray amorphous silicon flat panel. The WEPL values were derived solely from the root-mean-square (RMS) of DRFs, while the intensity information in the DRFs was filtered out. In this work, we explored the use of such intensity information for potential improvement in WEPL accuracy and imaging quality. Three WEPL derivation methods based on, respectively, the RMS only, the intensity only, and the intensity-weighted RMS were tested and compared in terms of the quality of obtained radiograph images and the accuracy of WEPL values. A Gammex CT calibration phantom containing inserts made of various tissue substitute materials with independently measured relative stopping powers (RSP) was used to assess the imaging performances. Improved image quality with enhanced interfaces was achieved while preserving the accuracy by using intensity information in the calibration. Other objects, including an anthropomorphic head phantom, a proton therapy range compensator, a frozen lamb’s head and an ‘image quality phantom’ were also imaged. Both the RMS only and the intensity-weighted RMS methods derived RSPs within  ±  1% for most of the Gammex phantom inserts, with a mean absolute percentage error of 0.66% for all inserts. In the case of the insert with a titanium rod, the method based on RMS completely failed, whereas that based on the intensity-weighted RMS was qualitatively valid. The use of intensity greatly enhanced the interfaces between different materials in the obtained WEPL images, suggesting the potential for image guidance in areas such as patient positioning and tumor tracking by proton

  2. Normal zone detectors for a large number of inductively coupled coils

    International Nuclear Information System (INIS)

    Owen, E.W.; Shimer, D.W.

    1983-01-01

    In order to protect a set of inductively coupled superconducting magnets, it is necessary to locate and measure normal zone voltages that are small compared with the mutual and self-induced voltages. The method described in this report uses two sets of voltage measurements to locate and measure one or more normal zones in any number of coupled coils. One set of voltages is the outputs of bridges that balance out the self-induced voltages The other set of voltages can be the voltages across the coils, although alternatives are possible. The two sets of equations form a single combined set of equations. Each normal zone location or combination of normal zones has a set of these combined equations associated with it. It is demonstrated that the normal zone can be located and the correct set chosen, allowing determination of the size of the normal zone. Only a few operations take plae in a working detector: multiplication of a constant, addition, and simple decision-making. In many cases the detector for each coil, although weakly linked to the other detectors, can be considered to be independent. An example of the detector design is given for four coils with realistic parameters. The effect on accuracy of changes in the system parameters is discussed

  3. Development of wide-band, time and energy resolving, optical photon detectors with application to imaging astronomy

    International Nuclear Information System (INIS)

    Miller, A.J.; Cabrera, B.; Romani, R.W.; Figueroa-Feliciano, E.; Nam, S.W.; Clarke, R.M.

    2000-01-01

    Superconducting transition edge sensors (TESs) are showing promise for the wide-band spectroscopy of individual photons from the mid-infrared (IR), through the optical, and into the near ultraviolet (UV). Our TES sensors are ∼20 μm square, 40 nm thick tungsten (W) films with a transition temperature of about 80 mK. We typically attain an energy resolution of 0.15 eV FWHM over the optical range with relative timing resolution of 100 ns. Single photon events with sub-microsecond risetimes and few microsecond falltimes have been achieved allowing count rates in excess of 30 kHz per pixel. Additionally, tungsten is approximately 50% absorptive in the optical (dropping to 10% in the IR) giving these devices an intrinsically high quantum efficiency. These combined traits make our detectors attractive for fast spectrophotometers and photon-starved applications such as wide-band, time and energy resolved astronomical observations. We present recent results from our work toward the fabrication and testing of the first TES optical photon imaging arrays

  4. Normal zone detectors for a large number of inductively coupled coils

    International Nuclear Information System (INIS)

    Owen, E.W.; Shimer, D.W.

    1983-01-01

    In order to protect a set of inductively coupled superconducting magnets, it is necessary to locate and measure normal zone voltages that are small compared with the mutual and self-induced voltages. The method described in this paper uses two sets of voltage measurements to locate and measure one or more normal zones in any number of coupled coils. One set of voltages is the outputs of bridges that balance out the self-induced voltages. The other set of voltages can be the voltages across the coils, although alternatives are possible. The two sets of equations form a single combined set of equations. Each normal zone location or combination of normal zones has a set of these combined equations associated with it. It is demonstrated that the normal zone can be located and the correct set chosen, allowing determination of the size of the normal zone. Only a few operations take place in a working detector: multiplication of a constant, addition, and simple decision-making. In many cases the detector for each coil, although weakly linked to the other detectors, can be considered to be independent

  5. Normal zone detectors for a large number of inductively coupled coils. Revision 1

    International Nuclear Information System (INIS)

    Owen, E.W.; Shimer, D.W.

    1983-01-01

    In order to protect a set of inductively coupled superconducting magnets, it is necessary to locate and measure normal zone voltages that are small compared with the mutual and self-induced voltages. The method described in this paper uses two sets of voltage measurements to locate and measure one or more normal zones in any number of coupled coils. One set of voltages is the outputs of bridges that balance out the self-induced voltages. The other set of voltages can be the voltages across the coils, although alternatives are possible. The two sets of equations form a single combined set of equations. Each normal zone location or combination of normal zones has a set of these combined equations associated with it. It is demonstrated that the normal zone can be located and the correct set chosen, allowing determination of the size of the normal zone. Only a few operations take place in a working detector: multiplication of a constant, addition, and simple decision-making. In many cases the detector for each coil, although weakly linked to the other detectors, can be considered to be independent. The effect on accuracy of changes in the system parameters is discussed

  6. Estimating the number of competing terminals without a state variation detector in wireless LAN

    Science.gov (United States)

    Lim, Jaechan; Kim, Taejin; Hong, Daehyoung

    2013-12-01

    Estimating the number of competing terminals n (who wish to transmit a packet at the same time) in the IEEE 802.11 system is important for system throughput performance because optimal back-off window size needs to be selected based on n. Therefore, as a new approach for estimating n, we propose H infinity filter that does not need a state variation detector as opposed to the cases of previously proposed approaches. The state variation detector's flaw is incurring tracking latency in addition to the side effect of increased computational cost. All previously proposed approaches demand the employment of the state variation detector to detect the variation of n in the IEEE 802.11 system. By employing H infinity filter, we show improved throughput performance of the system compared to that of previously proposed approaches (e.g., the Kalman filter and particle filter) based on the improved performance in tracking n. In this paper, we justify the superiority of the proposed approach in the terms of tracking performance, throughput performance, and computational complexity.

  7. Resolving both entrainment-mixing and number of activated CCN in deep convective clouds

    Directory of Open Access Journals (Sweden)

    E. Freud

    2011-12-01

    Full Text Available The number concentration of activated CCN (Na is the most fundamental microphysical property of a convective cloud. It determines the rate of droplet growth with cloud depth and conversion into precipitation-sized particles and affects the radiative properties of the clouds. However, measuring Na is not always possible, even in the cores of the convective clouds, because entrainment of sub-saturated ambient air deeper into the cloud lowers the concentrations by dilution and may cause partial or total droplet evaporation, depending on whether the mixing is homogeneous or extreme inhomogeneous, respectively.

    Here we describe a methodology to derive Na based on the rate of cloud droplet effective radius (Re growth with cloud depth and with respect to the cloud mixing with the entrained ambient air. We use the slope of the tight linear relationship between the adiabatic liquid water mixing ratio and Re3 (or Rv3 to derive an upper limit for Na assuming extreme inhomogeneous mixing. Then we tune Na down to find the theoretical relative humidity that the entrained ambient air would have for each horizontal cloud penetration, in case of homogeneous mixing. This allows us to evaluate both the entrainment and mixing process in the vertical dimension in addition to getting a better estimation for Na.

    We found that the derived Na from the entire profile data is highly correlated with the independent CCN measurements from below cloud base. Moreover, it was found that mixing of sub-saturated ambient air into the cloud at scales of ~100 m and above is inclined towards the extreme inhomogeneous limit, i.e. that the time scale of droplet evaporation is significantly smaller than that for turbulent mixing. This means that ambient air that entrains

  8. Size-resolved particle number emission patterns under real-world driving conditions using positive matrix factorization.

    Science.gov (United States)

    Domínguez-Sáez, Aida; Viana, Mar; Barrios, Carmen C; Rubio, Jose R; Amato, Fulvio; Pujadas, Manuel; Querol, Xavier

    2012-10-16

    A novel on-board system was tested to characterize size-resolved particle number emission patterns under real-world driving conditions, running in a EURO4 diesel vehicle and in a typical urban circuit in Madrid (Spain). Emission profiles were determined as a function of driving conditions. Source apportionment by Positive Matrix Factorization (PMF) was carried out to interpret the real-world driving conditions. Three emission patterns were identified: (F1) cruise conditions, with medium-high speeds, contributing in this circuit with 60% of total particle number and a particle size distribution dominated by particles >52 nm and around 60 nm; (F2) transient conditions, stop-and-go conditions at medium-high speed, contributing with 25% of the particle number and mainly emitting particles in the nucleation mode; and (F3) creep-idle conditions, representing traffic congestion and frequent idling periods, contributing with 14% to the total particle number and with particles in the nucleation mode (emissions depending on particle size and driving conditions. Differences between real-world emission patterns and regulatory cycles (NEDC) are also presented, which evidence that detecting particle number emissions real-world driving conditions.

  9. Comparison of CT numbers between cone-beam CT and multi-detector CT

    International Nuclear Information System (INIS)

    Kim, Dong Soo; Han, Won Jeong; Kim, Eun Kyung

    2010-01-01

    To compare the CT numbers on 3 cone-beam CT (CBCT) images with those on multi-detector CT (MDCT) image using CT phantom and to develop linear regressive equations using CT numbers to material density for all the CT scanner each. Mini CT phantom comprised of five 1 inch thick cylindrical models with 1.125 inches diameter of materials with different densities (polyethylene, polystyrene, plastic water, nylon and acrylic) was used. It was scanned in 3 CBCTs (i-CAT, Alphard VEGA, Implagraphy SC) and 1 MDCT (Somatom Emotion). The images were saved as DICOM format and CT numbers were measured using OnDemand 3D. CT numbers obtained from CBCTs and MDCT images were compared and linear regression analysis was performed for the density, ρ(g/cm 3 ), as the dependent variable in terms of the CT numbers obtained from CBCTs and MDCT images. CT numbers on i-CAT and Implagraphy CBCT images were smaller than those on Somatom Emotion MDCT image (p<0.05). Linear relationship on a range of materials used for this study were ρ=0.001 H+1.07 with R2 value of 0.999 for Somatom Emotion, ρ=0.002 H+1.09 with R2 value of 0.991 for Alphard VEGA, ρ=0.001 H+1.43 with R2 value of 0.980 for i-CAT and ρ=0.001 H+1.30 with R2 value of 0.975 for Implagraphy. CT numbers on i-CAT and Implagraphy CBCT images were not same as those on Somatom Emotion MDCT image. The linear regressive equations to determine the density from the CT numbers with very high correlation coefficient were obtained on three CBCT and MDCT scan.

  10. Comparison of CT numbers between cone-beam CT and multi-detector CT

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dong Soo; Han, Won Jeong; Kim, Eun Kyung [Department of Oral and Maxillofacial Radiology, School of Dentistry, Dankook University, Cheonan (Korea, Republic of)

    2010-06-15

    To compare the CT numbers on 3 cone-beam CT (CBCT) images with those on multi-detector CT (MDCT) image using CT phantom and to develop linear regressive equations using CT numbers to material density for all the CT scanner each. Mini CT phantom comprised of five 1 inch thick cylindrical models with 1.125 inches diameter of materials with different densities (polyethylene, polystyrene, plastic water, nylon and acrylic) was used. It was scanned in 3 CBCTs (i-CAT, Alphard VEGA, Implagraphy SC) and 1 MDCT (Somatom Emotion). The images were saved as DICOM format and CT numbers were measured using OnDemand 3D. CT numbers obtained from CBCTs and MDCT images were compared and linear regression analysis was performed for the density, {rho}(g/cm{sup 3}), as the dependent variable in terms of the CT numbers obtained from CBCTs and MDCT images. CT numbers on i-CAT and Implagraphy CBCT images were smaller than those on Somatom Emotion MDCT image (p<0.05). Linear relationship on a range of materials used for this study were {rho}=0.001 H+1.07 with R2 value of 0.999 for Somatom Emotion, {rho}=0.002 H+1.09 with R2 value of 0.991 for Alphard VEGA, {rho}=0.001 H+1.43 with R2 value of 0.980 for i-CAT and {rho}=0.001 H+1.30 with R2 value of 0.975 for Implagraphy. CT numbers on i-CAT and Implagraphy CBCT images were not same as those on Somatom Emotion MDCT image. The linear regressive equations to determine the density from the CT numbers with very high correlation coefficient were obtained on three CBCT and MDCT scan.

  11. Constraining neutron-star tidal Love numbers with gravitational-wave detectors

    International Nuclear Information System (INIS)

    Flanagan, Eanna E.; Hinderer, Tanja

    2008-01-01

    Ground-based gravitational wave detectors may be able to constrain the nuclear equation of state using the early, low frequency portion of the signal of detected neutron star-neutron star inspirals. In this early adiabatic regime, the influence of a neutron star's internal structure on the phase of the waveform depends only on a single parameter λ of the star related to its tidal Love number, namely, the ratio of the induced quadrupole moment to the perturbing tidal gravitational field. We analyze the information obtainable from gravitational wave frequencies smaller than a cutoff frequency of 400 Hz, where corrections to the internal-structure signal are less than 10%. For an inspiral of two nonspinning 1.4M · neutron stars at a distance of 50 Megaparsecs, LIGO II detectors will be able to constrain λ to λ≤2.0x10 37 g cm 2 s 2 with 90% confidence. Fully relativistic stellar models show that the corresponding constraint on radius R for 1.4M · neutron stars would be R≤13.6 km (15.3 km) for a n=0.5 (n=1.0) polytrope with equation of state p∝ρ 1+1/n

  12. System for high-voltage control detectors with large number photomultipliers

    International Nuclear Information System (INIS)

    Donskov, S.V.; Kachanov, V.A.; Mikhajlov, Yu.V.

    1985-01-01

    A simple and inexpensive on-line system for hihg-voltage control which is designed for detectors with a large number of photomultipliers is developed and manufactured. It has been developed for the GAMC type hodoscopic electromagnetic calorimeters, comprising up to 4 thousand photomultipliers. High voltage variation is performed by a high-speed potentiometer which is rotated by a microengine. Block-diagrams of computer control electronics are presented. The high-voltage control system has been used for five years in the IHEP and CERN accelerator experiments. The operation experience has shown that it is quite simple and convenient in operation. In case of about 6 thousand controlled channels in both experiments no potentiometer and microengines failures were observed

  13. A search for baryon- and lepton-number violating decays of $\\Lambda$ hyperons using the CLAS detector at Jefferson Laboratory

    OpenAIRE

    McCracken, M. E.; Bellis, M.; Adhikari, K. P.; Adikaram, D.; Akbar, Z.; Pereira, S. Anefalos; Badui, R. A.; Ball, J.; Baltzell, N. A.; Battaglieri, M.; Batourine, V.; Bedlinskiy, I.; Biselli, A. S.; Boiarinov, S.; Briscoe, W. J.

    2015-01-01

    We present a search for ten baryon-number violating decay modes of $\\Lambda$ hyperons using the CLAS detector at Jefferson Laboratory. Nine of these decay modes result in a single meson and single lepton in the final state ($\\Lambda \\rightarrow m \\ell$) and conserve either the sum or the difference of baryon and lepton number ($B \\pm L$). The tenth decay mode ($\\Lambda \\rightarrow \\bar{p}\\pi^+$) represents a difference in baryon number of two units and no difference in lepton number. We obser...

  14. Intrinsic sensitivity calculation for a large number of LiF(Mg, Cu, P) detectors

    International Nuclear Information System (INIS)

    Argazzi, E.; Baldassarre, G.; De Maio, U.; Fantuzzi, E.; Monteventi, F.; Uleri, G.

    1996-07-01

    At the ENEA (Italian National Agency for New Technologies, Energy and the Environment) Personal Dosimetry Service it was decided to substitute the X and gamma dosimetry system based on BeO detectors in use since 10 years ago, with new dosimeters based on the new thermoluminescence material LiF(Mg,Cu,P). This report describes the procedures through which intrinsic sensitivity of a couple of TL detectors, which constitutes a card dosemeter, is determined. The intrinsic sensitivity archive allows to calculate the value of dose applying a specific correction factor for the systematic sensitivity, difference among the 60000 detectors used at the Service, therefore reducing the final uncertainty. The characterization of 60000 TL detectors has been possible only relying on a specific procedure and an informatic system. The irradiation and reading procedure allowed to take into account all the various uncertainty sources on TL readings and to carry out only one reading for almost all detectors. It could get through this aim using a reference group of dosimeters, characterized with an accuracy of 3%, to check each uncertainty parameter. Data acquisition and intrinsic sensitivity calculation have been carried out through an interactive procedure based on a personal computer connected with the reading instrument

  15. Generation of sub-Poissonian non-Gaussian states from multimode twin beams by photon-number-resolving detectors

    Czech Academy of Sciences Publication Activity Database

    Lamperti, M.; Allevi, A.; Bondani, M.; Machulka, R.; Michálek, Václav; Haderka, O.; Peřina Jr., J.

    2014-01-01

    Roč. 12, č. 2 (2014), "1461017-1"-"1461017-7" ISSN 0219-7499 R&D Projects: GA ČR GAP205/12/0382 Institutional support: RVO:68378271 Keywords : quantum state engineering and measurements * parametric down-conversion * photodetectors * sub-Poissonian statistics * non-Gaussianity Subject RIV: BH - Optics, Masers, Lasers Impact factor: 0.877, year: 2014

  16. Search for baryon-number and lepton-number violating decays of Λ hyperons using the CLAS detector at Jefferson Laboratory

    Science.gov (United States)

    McCracken, M. E.; Bellis, M.; Adhikari, K. P.; Adikaram, D.; Akbar, Z.; Pereira, S. Anefalos; Badui, R. A.; Ball, J.; Baltzell, N. A.; Battaglieri, M.; Batourine, V.; Bedlinskiy, I.; Biselli, A. S.; Boiarinov, S.; Briscoe, W. J.; Brooks, W. K.; Burkert, V. D.; Cao, T.; Carman, D. S.; Celentano, A.; Chandavar, S.; Charles, G.; Colaneri, L.; Cole, P. L.; Contalbrigo, M.; Cortes, O.; Crede, V.; D'Angelo, A.; Dashyan, N.; De Vita, R.; De Sanctis, E.; Deur, A.; Djalali, C.; Dodge, G. E.; Dupre, R.; Alaoui, A. El; Fassi, L. El; Elouadrhiri, E.; Eugenio, P.; Fedotov, G.; Fegan, S.; Fersch, R.; Filippi, A.; Fleming, J. A.; Garillon, B.; Gevorgyan, N.; Gilfoyle, G. P.; Giovanetti, K. L.; Girod, F. X.; Golovatch, E.; Gothe, R. W.; Griffioen, K. A.; Guidal, M.; Guo, L.; Hafidi, K.; Hakobyan, H.; Hanretty, C.; Hattawy, M.; Hicks, K.; Holtrop, M.; Hughes, S. M.; Ilieva, Y.; Ireland, D. G.; Ishkhanov, B. S.; Isupov, E. L.; Jenkins, D.; Jiang, H.; Jo, H. S.; Keller, D.; Khachatryan, G.; Khandaker, M.; Kim, A.; Kim, W.; Klein, A.; Klein, F. J.; Kubarovsky, V.; Lenisa, P.; Livingston, K.; Lu, H. Y.; MacGregor, I. J. D.; Mayer, M.; McKinnon, B.; Mestayer, M. D.; Meyer, C. A.; Mirazita, M.; Mokeev, V.; Moody, C. I.; Moriya, K.; Camacho, C. Munoz; Nadel-Turonski, P.; Net, L. A.; Niccolai, S.; Osipenko, M.; Ostrovidov, A. I.; Park, K.; Pasyuk, E.; Pisano, S.; Pogorelko, O.; Price, J. W.; Procureur, S.; Prok, Y.; Raue, B. A.; Ripani, M.; Rizzo, A.; Rosner, G.; Roy, P.; Sabatié, F.; Salgado, C.; Schumacher, R. A.; Seder, E.; Sharabian, Y. G.; Skorodumina, Iu.; Sokhan, D.; Sparveris, N.; Stoler, P.; Strakovsky, I. I.; Strauch, S.; Sytnik, V.; Tian, Ye; Ungaro, M.; Voskanyan, H.; Voutier, E.; Walford, N. K.; Watts, D. P.; Wei, X.; Wood, M. H.; Zachariou, N.; Zana, L.; Zhang, J.; Zhao, Z. W.; Zonta, I.; CLAS Collaboration

    2015-10-01

    We present a search for ten baryon number violating decay modes of Λ hyperons using the CLAS detector at Jefferson Laboratory. Nine of these decay modes result in a single meson and single lepton in the final state (Λ →m ℓ) and conserve either the sum or the difference of baryon and lepton number (B ±L ). The tenth decay mode (Λ →p ¯ π+ ) represents a difference in baryon number of two units and no difference in lepton number. We observe no significant signal and set upper limits on the branching fractions of these reactions in the range (4 - 200 )×10-7 at the 90% confidence level.

  17. Size-resolved mass concentrations of iron oxide aerosols and size-resolved number concentrations of iron oxide aerosols collected from King Air aircraft in Yellow Sea and East China Sea from 2013-02-14 to 2013-03-10 (NCEI Accession 0162201)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains size-resolved mass concentrations of iron oxide aerosols and size-resolved number concentrations of iron oxide aerosols, measured using the...

  18. Enforcement actions: Significant actions resolved -- individual actions. Semiannual progress report, July--December 1997; Volume 16, Number 2, Part 1

    International Nuclear Information System (INIS)

    1998-04-01

    This compilation summarizes significant enforcement actions that have been resolved during the period (July--December 1997) and includes copies of Orders and Notices of Violation sent by the Nuclear Regulatory Commission to individuals with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC. The Commission believes this information may be useful to licensees in making employment decisions

  19. Enforcement actions: Significant actions resolved -- individual actions. Semiannual progress report, July--December 1997; Volume 16, Number 2, Part 1

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-04-01

    This compilation summarizes significant enforcement actions that have been resolved during the period (July--December 1997) and includes copies of Orders and Notices of Violation sent by the Nuclear Regulatory Commission to individuals with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC. The Commission believes this information may be useful to licensees in making employment decisions.

  20. Dose optimization for dual-energy contrast-enhanced digital mammography based on an energy-resolved photon-counting detector: A Monte Carlo simulation study

    Science.gov (United States)

    Lee, Youngjin; Lee, Seungwan; Kang, Sooncheol; Eom, Jisoo

    2017-03-01

    Dual-energy contrast-enhanced digital mammography (CEDM) has been used to decompose breast images and improve diagnostic accuracy for tumor detection. However, this technique causes an increase of radiation dose and an inaccuracy in material decomposition due to the limitations of conventional X-ray detectors. In this study, we simulated the dual-energy CEDM with an energy-resolved photon-counting detector (ERPCD) for reducing radiation dose and improving the quantitative accuracy of material decomposition images. The ERPCD-based dual-energy CEDM was compared to the conventional dual-energy CEDM in terms of radiation dose and quantitative accuracy. The correlation between radiation dose and image quality was also evaluated for optimizing the ERPCD-based dual-energy CEDM technique. The results showed that the material decomposition errors of the ERPCD-based dual-energy CEDM were 0.56-0.67 times lower than those of the conventional dual-energy CEDM. The imaging performance of the proposed technique was optimized at the radiation dose of 1.09 mGy, which is a half of the MGD for a single view mammogram. It can be concluded that the ERPCD-based dual-energy CEDM with an optimal exposure level is able to improve the quality of material decomposition images as well as reduce radiation dose.

  1. RHIC detector electronics R and D proposal (number-sign RH-8) - development of analog memories for RHIC detector front-end electronic systems

    International Nuclear Information System (INIS)

    Konstantinidis, A.; Ledoux, R.; Steadman, S.; Stephans, G.; Wadsworth, B.

    1990-01-01

    Detectors for colliding beam experiments at RHIC will provide 4pi coverage and are expected to contain from 10**5 to 10**6 channels. As the 2 to 5usec required to generate first-level triggers is long compared with RHIC's 114nsec beam crossing interval, there will be a need not only to deal with signals from a great number of channels but also to store and tag these signals over many beam crossings. The authors are concentrating their efforts on developing the switched-capacitor (SC) analog memory as the generic mechanism for storing detector signals. Switched-capacitor circuits can be implemented using metaloxide-semiconductor (MOS) technology; and, for development work, they have relatively easy access to a number of foundries running different MOS processes the choice of which would depend on the exact nature of their application. In terms of memory applications, several MOS-based designs have been reported in the literature. MOS technology is generally considered to have advantages over charge-coupled devices in terms of lower power dissipation, lower noise, better linearity, better radiation hardness, and lower cost: all desirable characteristics for a device to be used in a particle detector. However, the authors have recently learned of new developments in CCD technology at MIT's Lincoln Laboratory, and they find that the advantage of MOS technology over CCD technology, at least in terms of the parameters mentioned above, may not be as marked as once thought. Since CCD's have some interesting features which make them potentially useful for pipeline trigger applications, if not for the more general storage applications they are considering here, they intend to keep in close contact with this work

  2. Dose optimization for dual-energy contrast-enhanced digital mammography based on an energy-resolved photon-counting detector: A Monte Carlo simulation study

    International Nuclear Information System (INIS)

    Lee, Youngjin; Lee, Seungwan; Kang, Sooncheol; Eom, Jisoo

    2017-01-01

    Dual-energy contrast-enhanced digital mammography (CEDM) has been used to decompose breast images and improve diagnostic accuracy for tumor detection. However, this technique causes an increase of radiation dose and an inaccuracy in material decomposition due to the limitations of conventional X-ray detectors. In this study, we simulated the dual-energy CEDM with an energy-resolved photon-counting detector (ERPCD) for reducing radiation dose and improving the quantitative accuracy of material decomposition images. The ERPCD-based dual-energy CEDM was compared to the conventional dual-energy CEDM in terms of radiation dose and quantitative accuracy. The correlation between radiation dose and image quality was also evaluated for optimizing the ERPCD-based dual-energy CEDM technique. The results showed that the material decomposition errors of the ERPCD-based dual-energy CEDM were 0.56–0.67 times lower than those of the conventional dual-energy CEDM. The imaging performance of the proposed technique was optimized at the radiation dose of 1.09 mGy, which is a half of the MGD for a single view mammogram. It can be concluded that the ERPCD-based dual-energy CEDM with an optimal exposure level is able to improve the quality of material decomposition images as well as reduce radiation dose. - Highlights: • Dual-energy mammography based on a photon-counting detector was simulated. • Radiation dose and image quality were evaluated for optimizing the proposed technique. • The proposed technique reduced radiation dose as well as improved image quality. • The proposed technique was optimized at the radiation dose of 1.09 mGy.

  3. Figures of merit for detectors in digital radiography. II. Finite number of secondaries and structured backgrounds

    International Nuclear Information System (INIS)

    Pineda, Angel R.; Barrett, Harrison H.

    2004-01-01

    The current paradigm for evaluating detectors in digital radiography relies on Fourier methods. Fourier methods rely on a shift-invariant and statistically stationary description of the imaging system. The theoretical justification for the use of Fourier methods is based on a uniform background fluence and an infinite detector. In practice, the background fluence is not uniform and detector size is finite. We study the effect of stochastic blurring and structured backgrounds on the correlation between Fourier-based figures of merit and Hotelling detectability. A stochastic model of the blurring leads to behavior similar to what is observed by adding electronic noise to the deterministic blurring model. Background structure does away with the shift invariance. Anatomical variation makes the covariance matrix of the data less amenable to Fourier methods by introducing long-range correlations. It is desirable to have figures of merit that can account for all the sources of variation, some of which are not stationary. For such cases, we show that the commonly used figures of merit based on the discrete Fourier transform can provide an inaccurate estimate of Hotelling detectability

  4. Enforcement actions: Significant actions resolved, reactor licensees. Quarterly progress report, July--September 1994; Volume 13, Number 3, Part 1

    International Nuclear Information System (INIS)

    1994-12-01

    This compilation summarizes significant enforcement actions that have been resolved during one quarterly period (July--September 1994) and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to reactor licensees with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication

  5. Enforcement actions: Significant actions resolved, medical licensees. Quarterly progress report, July--September 1994: Volume 13, Number 3, Part 2

    International Nuclear Information System (INIS)

    1994-12-01

    This compilation summarizes significant enforcement actions that have been resolved during one quarterly period (July--September 1994) and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to medical licensees with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication

  6. Enforcement actions: Significant actions resolved, reactor licensees. Semiannual progress report, July--December 1997; Volume 16, Number 2, Part 2

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-04-01

    This compilation summarizes significant enforcement actions that have been resolved during the period (July--December 1997) and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to reactor licensees with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication.

  7. Enforcement actions: Significant actions resolved, material licensees. Semiannual progress report, July--December 1997; Volume 16, Number 2, Part 3

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-04-01

    This compilation summarizes significant enforcement actions that have been resolved during the period (July--December 1997) and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to material licensees with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication.

  8. Enforcement actions: Significant actions resolved, material licensees. Semiannual progress report, July--December 1997; Volume 16, Number 2, Part 3

    International Nuclear Information System (INIS)

    1998-04-01

    This compilation summarizes significant enforcement actions that have been resolved during the period (July--December 1997) and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to material licensees with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication

  9. Enforcement actions: Significant actions resolved, reactor licensees. Semiannual progress report, January--June 1997; Volume 16, Number 1, Part 2

    International Nuclear Information System (INIS)

    1997-09-01

    This compilation summarizes significant enforcement actions that have been resolved during the period (January--June 1997) and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to reactor licensees with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication

  10. Enforcement actions: Significant actions resolved, reactor licensees. Semiannual progress report, July--December 1997; Volume 16, Number 2, Part 2

    International Nuclear Information System (INIS)

    1998-04-01

    This compilation summarizes significant enforcement actions that have been resolved during the period (July--December 1997) and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to reactor licensees with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication

  11. Effective atomic numbers, electron densities, and tissue equivalence of some gases and mixtures for dosimetry of radiation detectors

    Directory of Open Access Journals (Sweden)

    Singh Vishwanath P.

    2012-01-01

    Full Text Available Total mass attenuation coefficients, µm, effective atomic number, Zeff, and effective electron density, Neff, of different gases - carbon dioxide, methane, acetylene, propane, butane, and pentane used in radiation detectors, have been calculated for the photon energy of 1 keV to 100 GeV. Each gas has constant Zeff values between 0.10 to 10 MeV photon energies; however, these values are way far away from ICRU tissue. Carbon dioxide gas shows the closest tissue equivalence in the entire photon energy spectrum. Relative tissue equivalences of the mixtures of gases with respect to ICRU tissue are in the range of 0.998-1.041 for air, argon (4.5% + methane (95.5%, argon (0.5% + carbon dioxide (99.5%, and nitrogen (5% + methane (7% + carbon dioxide (88%. The gas composition of xenon (0.5% + carbon dioxide (99.5% shows 1.605 times higher tissue equivalence compared to the ICRU tissue. The investigated photon interaction parameters are useful for exposure and energy absorption buildup factors calculation and design, and fabrication of gaseous detectors for ambient radiation measurement by the Geiger-Muller detector, ionization chambers and proportional counters.

  12. Simulation study comparing the helmet-chin PET with a cylindrical PET of the same number of detectors

    Science.gov (United States)

    Ahmed, Abdella M.; Tashima, Hideaki; Yoshida, Eiji; Nishikido, Fumihiko; Yamaya, Taiga

    2017-06-01

    There is a growing interest in developing brain PET scanners with high sensitivity and high spatial resolution for early diagnosis of neurodegenerative diseases and studies of brain functions. Sensitivity of the PET scanner can be improved by increasing the solid angle. However, conventional PET scanners are designed based on a cylindrical geometry, which may not be the most efficient design for brain imaging in terms of the balance between sensitivity and cost. We proposed a dedicated brain PET scanner based on a hemispheric shape detector and a chin detector (referred to as the helmet-chin PET), which is designed to maximize the solid angle by increasing the number of lines-of-response in the hemisphere. The parallax error, which PET scanners with a large solid angle tend to have, can be suppressed by the use of depth-of-interaction detectors. In this study, we carry out a realistic evaluation of the helmet-chin PET using Monte Carlo simulation based on the 4-layer GSO detector which consists of a 16  ×  16  ×  4 array of crystals with dimensions of 2.8  ×  2.8  ×  7.5 mm3. The purpose of this simulation is to show the gain in imaging performance of the helmet-chin PET compared with the cylindrical PET using the same number of detectors in each configuration. The sensitivity of the helmet-chin PET evaluated with a cylindrical phantom has a significant increase, especially at the top of the (field-of-view) FOV. The peak-NECR of the helmet-chin PET is 1.4 times higher compared to the cylindrical PET. The helmet-chin PET provides relatively low noise images throughout the FOV compared to the cylindrical PET which exhibits enhanced noise at the peripheral regions. The results show the helmet-chin PET can significantly improve the sensitivity and reduce the noise in the reconstructed images.

  13. Texture analysis with neutron bending on geological/mineralogical multi-phase samples using a locally resolving detector and profile analysis

    International Nuclear Information System (INIS)

    Merz, P.L.

    1991-02-01

    In the context of this work, the NANCY four circuit diffractometer of the University of Bonn at the RRJ2 research reactor at KFA Juelich was equipped with a linear locally resolving scintillation detector JULIOS. To evaluate the diffractogram occurring at a pole figure measurement, user-friendly profile analysis and other evaluation programs were developed on the PC. The course of evaluation was largely automated, so that only a few interactive steps are required. The measuring period of a sample is usually two to three days. Up to 35 pole figures are produced, depending on the phase conditions of the examined sample. The evaluation of up to 900 diffractograms with the aid of the automatically running profile analysis program takes between 30 and 100 minutes on a 20 MHz PC 386. Pole figure datafiles are produced from the intensity data obtained in this way by a conversion program. The texture analyses of copper pyrites ores introduced here are connected with geological questions. (orig.) [de

  14. Acceptor number-dependent ultrafast photo-physical properties of push-pull chromophores using time-resolved methods

    Science.gov (United States)

    Chi, Xiao-Chun; Wang, Ying-Hui; Gao, Yu; Sui, Ning; Zhang, Li-Quan; Wang, Wen-Yan; Lu, Ran; Ji, Wen-Yu; Yang, Yan-Qiang; Zhang, Han-Zhuang

    2018-04-01

    Three push-pull chromophores comprising a triphenylamine (TPA) as electron-donating moiety and functionalized β-diketones as electron acceptor units are studied by various spectroscopic techniques. The time-correlated single-photon counting data shows that increasing the number of electron acceptor units accelerates photoluminescence relaxation rate of compounds. Transient spectra data shows that intramolecular charge transfer (ICT) takes place from TPA units to β-diketones units after photo-excitation. Increasing the number of electron acceptor units would prolong the generation process of ICT state, and accelerate the excited molecule reorganization process and the relaxation process of ICT state.

  15. Evaluation of Origin Ensemble algorithm for image reconstruction for pixelated solid-state detectors with large number of channels

    Science.gov (United States)

    Kolstein, M.; De Lorenzo, G.; Mikhaylova, E.; Chmeissani, M.; Ariño, G.; Calderón, Y.; Ozsahin, I.; Uzun, D.

    2013-04-01

    The Voxel Imaging PET (VIP) Pathfinder project intends to show the advantages of using pixelated solid-state technology for nuclear medicine applications. It proposes designs for Positron Emission Tomography (PET), Positron Emission Mammography (PEM) and Compton gamma camera detectors with a large number of signal channels (of the order of 106). For PET scanners, conventional algorithms like Filtered Back-Projection (FBP) and Ordered Subset Expectation Maximization (OSEM) are straightforward to use and give good results. However, FBP presents difficulties for detectors with limited angular coverage like PEM and Compton gamma cameras, whereas OSEM has an impractically large time and memory consumption for a Compton gamma camera with a large number of channels. In this article, the Origin Ensemble (OE) algorithm is evaluated as an alternative algorithm for image reconstruction. Monte Carlo simulations of the PET design are used to compare the performance of OE, FBP and OSEM in terms of the bias, variance and average mean squared error (MSE) image quality metrics. For the PEM and Compton camera designs, results obtained with OE are presented.

  16. Are low and high number magnitudes processed differently while resolving the conflict evoked by the SNARC effect?

    Science.gov (United States)

    Gut, Małgorzata; Szumska, Izabela; Wasilewska, Marzena; Jaśkowski, Piotr

    2012-07-01

    In the brain, numbers are thought to be represented in a spatially organised fashion on what is known as the Mental Number Line (MNL). The SNARC (Spatial-Numerical Association of Response Codes) effect refers to the faster responses to digits when the reaction side is congruent with the digit position on the MNL (e.g. a left-handed response to a small magnitude) and the slowing down of responses (inhibition) in the case of incongruity. We examined the electrophysiological correlates of conflict, which are linked to that of inhibition, to shed light on the relationship between the SNARC effect and executive attention. Event-related potentials (ERPs) were recorded from twenty-nine participants during a parity-judgment task. The participants responded more quickly on congruent than on incongruent trials. The congruency effect was reflected in early sensory (N1, N2) components above parieto-occipital and frontal regions, as well as in the later P3 component above centro-parietal areas. Moreover, both the N1 amplitude and N2 latency were greater with high than low magnitude digit targets. P3 amplitude modulation implies that the SNARC effect is the result of first evoking the parallel processing of digit magnitude categorisation (in the occipital and central areas) and numeric conflict detection (in the parieto-occipital and frontal areas) and secondly conflict monitoring and resolution localised in the centro-parietal and frontal sites. These results also suggest that the left hemisphere specialises in conflict processing of high magnitude digit targets, while the right hemisphere of low digit magnitudes. Copyright © 2012 Elsevier B.V. All rights reserved.

  17. Time-resolved study of the electron temperature and number density of argon metastable atoms in argon-based dielectric barrier discharges

    Science.gov (United States)

    Desjardins, E.; Laurent, M.; Durocher-Jean, A.; Laroche, G.; Gherardi, N.; Naudé, N.; Stafford, L.

    2018-01-01

    A combination of optical emission spectroscopy and collisional-radiative modelling is used to determine the time-resolved electron temperature (assuming Maxwellian electron energy distribution function) and number density of Ar 1s states in atmospheric pressure Ar-based dielectric barrier discharges in presence of either NH3 or ethyl lactate. In both cases, T e values were higher early in the discharge cycle (around 0.8 eV), decreased down to about 0.35 eV with the rise of the discharge current, and then remained fairly constant during discharge extinction. The opposite behaviour was observed for Ar 1s states, with cycle-averaged values in the 1017 m-3 range. Based on these findings, a link was established between the discharge ionization kinetics (and thus the electron temperature) and the number density of Ar 1s state.

  18. Quantification of Biogenic Volatile Organic Compounds with a Flame Ionization Detector Using the Effective Carbon Number Concept

    Science.gov (United States)

    Faiola, C. L.; Erickson, M. H.; Fricaud, V. L.; Wallace, H. W.; Jobson, B. T.; VanReken, T. M.

    2011-12-01

    Biogenic volatile organic compounds (BVOCs) are emitted into the atmosphere by plants and include structurally complex organic molecules such as monoterpenes, sesquiterpenes, and their oxygenated derivatives. These BVOCs are among the principle factors influencing the oxidative capacity of the atmosphere in forested regions. BVOC emission rates are often measured by collecting samples onto adsorptive cartridges in the field and then transporting these samples to the laboratory for chromatographic analysis. One of the most commonly used detectors in gas chromatography is the flame ionization detector (FID) due to its broad linear range, high sensitivity, and predictable response to many compounds. The FID response to saturated aliphatic molecules is proportional to carbon number. However, deviations occur as the complexity of the molecular structure increases. To account for these deviations, Sternberg et al. (1962) developed the effective carbon number (ECN) concept, which describes the number of carbons the FID "effectively" responds to. The ECN of a complex molecule can be estimated from the number and type of functional groups present, allowing an estimate of relative response factors for quantification. This approach is particularly useful for applications where samples contain a mixture of organic compounds and standards are not realistically accessible- a common predicament for environmental measurements. ECNs for a limited number of compounds with varying functional groups have been quantified in previous studies. However, there remain large gaps in the variety of compounds for which published data are available. This results in higher than necessary uncertainties when quantifying compounds that are structurally dissimilar to those that have been reported in the literature. The purpose of this study was to determine the ECN for a variety of terpenoid compounds to enable improved quantification of BVOC measurements. A dynamic dilution system was developed to

  19. Noise, sampling, and the number of projections in cone-beam CT with a flat-panel detector

    International Nuclear Information System (INIS)

    Zhao, Z.; Gang, G. J.; Siewerdsen, J. H.

    2014-01-01

    Purpose: To investigate the effect of the number of projection views on image noise in cone-beam CT (CBCT) with a flat-panel detector. Methods: This fairly fundamental consideration in CBCT system design and operation was addressed experimentally (using a phantom presenting a uniform medium as well as statistically motivated “clutter”) and theoretically (using a cascaded systems model describing CBCT noise) to elucidate the contributing factors of quantum noise (σ Q ), electronic noise (σ E ), and view aliasing (σ view ). Analysis included investigation of the noise, noise-power spectrum, and modulation transfer function as a function of the number of projections (N proj ), dose (D tot ), and voxel size (b vox ). Results: The results reveal a nonmonotonic relationship between image noise andN proj at fixed total dose: for the CBCT system considered, noise decreased with increasing N proj due to reduction of view sampling effects in the regime N proj proj due to increased electronic noise. View sampling effects were shown to depend on the heterogeneity of the object in a direct analytical relationship to power-law anatomical clutter of the form κ/f  β —and a general model of individual noise components (σ Q , σ E , and σ view ) demonstrated agreement with measurements over a broad range in N proj , D tot , and b vox . Conclusions: The work elucidates fairly basic elements of CBCT noise in a manner that demonstrates the role of distinct noise components (viz., quantum, electronic, and view sampling noise). For configurations fairly typical of CBCT with a flat-panel detector (FPD), the analysis reveals a “sweet spot” (i.e., minimum noise) in the rangeN proj ∼ 250–350, nearly an order of magnitude lower in N proj than typical of multidetector CT, owing to the relatively high electronic noise in FPDs. The analysis explicitly relates view aliasing and quantum noise in a manner that includes aspects of the object (“clutter”) and imaging chain

  20. Characteristics of Ambient Black Carbon Mass and Size-Resolved Particle Number Concentrations during Corn Straw Open-Field Burning Episode Observations at a Rural Site in Southern Taiwan.

    Science.gov (United States)

    Cheng, Yu-Hsiang; Yang, Li-Sing

    2016-07-08

    Information on the effect of open-field burning of agricultural residues on ambient black carbon (BC) mass and size-resolved particle number concentrations is scarce. In this study, to understand the effect of such open-field burning on short-term air quality, real-time variations of the BC mass and size-resolved particle number concentrations were monitored before and during a corn straw open-field burning episode at a rural site. Correlations between the BC mass and size-resolved particle number concentrations during the episode were investigated. Moreover, the particle number size distribution and absorption Ångström exponent were determined for obtaining the characteristics of aerosol emissions from the corn straw open-field burning. The results can be used to address public health concerns and as a reference for managing similar episodes of open-field burning of agricultural residues.

  1. Characterization and first experimental application of space-resolving, energy-dispersive germanium detectors for the precision spectroscopy on heavy ions

    International Nuclear Information System (INIS)

    Spillmann, Uwe

    2009-02-01

    First the actual status of the research for the 1s Lamb shift on heaviest systems as well as studies on the polarization of the radiative recombination radiation into the K shell of uranium are presented. On this base future precision experiments at storage rings are discussed. then follows a survey presentation of the GSI accelerator facility. Especially the experimental storage ring ESR is described, at which the experiments mentioned above were performed. Then an introduction to the fundamental understanding of the physical processes in the detection of X-radiation in semiconductor detectors is given. The following chapter discusses the detection technique of the Compton polarimetry and some experimental concepts for this. Then by means of a 4 x 4 pixel Ge(i) detector system, by which for the first time the K-REC radiation from uranium was measured at the ESR, an overview about the Monte-Carlo software EGS4 is given, which was applied to the efficiency correction in the evaluation phase and for the estimation of the detector behaviour during the planning phase of the new detectors. A presentation of the 1D and 2D microstrip detector system as well as the performed laboratory measurements follows. The results for the characterization of the 2D microstrip detector system at the synchrotron-radiation source ESRF in view of its application with the FOCAL spectrometer are thereafter described. The results of first test measurement on the Compton polarimetry, which were also performed at the ESRF, are then presented. Finally first experimental results, which wer obtained by the novel planar structured Ge(i) detectors, are shown

  2. A high count rate one-dimensional position sensitive detector and a data acquisition system for time resolved X-ray scattering studies

    International Nuclear Information System (INIS)

    Pernot, P.

    1982-01-01

    A curved multiwire proportional drift chamber has been built as a general purpose instrument for X-ray scattering and X-ray diffraction experiments with synchrotron radiation. This parallaxe-free one-dimensional linear position sensitive detector has a parallel readout with a double hit logic. The data acquisition system, installed as a part of the D11 camera at LURE-DCI, is designed to perform time slicing and cyclic experiments; it has been used with either the fast multiwire chamber or a standard position sensitive detector with delay line readout [fr

  3. Clinical array-based karyotyping of breast cancer with equivocal HER2 status resolves gene copy number and reveals chromosome 17 complexity

    International Nuclear Information System (INIS)

    Gunn, Shelly; Gorre, Mercedes; Mohammed, Mansoor; Yeh, I-Tien; Lytvak, Irina; Tirtorahardjo, Budi; Dzidic, Natasha; Zadeh, Soheila; Kim, Jaeweon; McCaskill, Chris; Lim, Lony

    2010-01-01

    HER2 gene copy status, and concomitant administration of trastuzumab (Herceptin), remains one of the best examples of targeted cancer therapy based on understanding the genomic etiology of disease. However, newly diagnosed breast cancer cases with equivocal HER2 results present a challenge for the oncologist who must make treatment decisions despite the patient's unresolved HER2 status. In some cases both immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) are reported as equivocal, whereas in other cases IHC results and FISH are discordant for positive versus negative results. The recent validation of array-based, molecular karyotyping for clinical oncology testing provides an alternative method for determination of HER2 gene copy number status in cases remaining unresolved by traditional methods. In the current study, DNA extracted from 20 formalin fixed paraffin embedded (FFPE) tissue samples from newly diagnosed cases of invasive ductal carcinoma referred to our laboratory with unresolved HER2 status, were analyzed using a clinically validated genomic array containing 127 probes covering the HER2 amplicon, the pericentromeric regions, and both chromosome 17 arms. Array-based comparative genomic hybridization (array CGH) analysis of chromosome 17 resolved HER2 gene status in [20/20] (100%) of cases and revealed additional chromosome 17 copy number changes in [18/20] (90%) of cases. Array CGH analysis also revealed two false positives and one false negative by FISH due to 'ratio skewing' caused by chromosomal gains and losses in the centromeric region. All cases with complex rearrangements of chromosome 17 showed genome-wide chromosomal instability. These results illustrate the analytical power of array-based genomic analysis as a clinical laboratory technique for resolution of HER2 status in breast cancer cases with equivocal results. The frequency of complex chromosome 17 abnormalities in these cases suggests that the two

  4. Material-specific imaging system using energy-dispersive X-ray diffraction and spatially resolved CdZnTe detectors with potential application in breast imaging

    Energy Technology Data Exchange (ETDEWEB)

    Barbes, Damien, E-mail: damien.barbes@cea.fr [Univ. Grenoble Alpes, F-38000 Grenoble (France); CEA, LETI, MINATEC Campus, F-38054 Grenoble (France); Tabary, Joachim, E-mail: joachim.tabary@cea.fr [Univ. Grenoble Alpes, F-38000 Grenoble (France); CEA, LETI, MINATEC Campus, F-38054 Grenoble (France); Paulus, Caroline, E-mail: caroline.paulus@cea.fr [Univ. Grenoble Alpes, F-38000 Grenoble (France); CEA, LETI, MINATEC Campus, F-38054 Grenoble (France); Hazemann, Jean-Louis, E-mail: jean-louis.hazemann@neel.cnrs.fr [Univ.Grenoble Alpes, Inst NEEL, F-38042 Grenoble (France); CNRS, Inst NEEL, F-38042 Grenoble (France); Verger, Loïck, E-mail: loick.verger@cea.fr [Univ. Grenoble Alpes, F-38000 Grenoble (France); CEA, LETI, MINATEC Campus, F-38054 Grenoble (France)

    2017-03-11

    This paper presents a coherent X-ray-scattering imaging technique using a multipixel energy-dispersive system. Without any translation, the technique produces specific 1D image from data recorded by a single CdZnTe detector pixel using subpixelation techniques. The method is described in detail, illustrated by a simulation and then experimentally validated. As the main considered application of our study is breast imaging, this validation involves 2D imaging of a phantom made of plastics mimicking breast tissues. The results obtained show that our system can specifically image the phantom using a single detector pixel. For the moment, in vivo breast imaging applications remain difficult, as the dose delivered by the system is too high, but some adjustments are considered for further work.

  5. High-speed x-ray imaging with the Keck pixel array detector (Keck PAD) for time-resolved experiments at synchrotron sources

    Energy Technology Data Exchange (ETDEWEB)

    Philipp, Hugh T., E-mail: htp2@cornell.edu; Tate, Mark W.; Purohit, Prafull; Shanks, Katherine S.; Weiss, Joel T. [Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, NY (United States); Chamberlain, Darol; Gruner, Sol M. [Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, NY (United States); Cornell High Energy Synchrotron Source (CHESS), Cornell University, Ithaca, NY (United States)

    2016-07-27

    Modern storage rings are readily capable of providing intense x-ray pulses, tens of picoseconds in duration, millions of times per second. Exploiting the temporal structure of these x-ray sources opens avenues for studying rapid structural changes in materials. Many processes (e.g. crack propagation, deformation on impact, turbulence, etc.) differ in detail from one sample trial to the next and would benefit from the ability to record successive x-ray images with single x-ray sensitivity while framing at 5 to 10 MHz rates. To this end, we have pursued the development of fast x-ray imaging detectors capable of collecting bursts of images that enable the isolation of single synchrotron bunches and/or bunch trains. The detector technology used is the hybrid pixel array detector (PAD) with a charge integrating front-end, and high-speed, in-pixel signal storage elements. A 384×256 pixel version, the Keck-PAD, with 150 µm × 150 µm pixels and 8 dedicated in-pixel storage elements is operational, has been tested at CHESS, and has collected data for compression wave studies. An updated version with 27 dedicated storage capacitors and identical pixel size has been fabricated.

  6. Detector decoy quantum key distribution

    International Nuclear Information System (INIS)

    Moroder, Tobias; Luetkenhaus, Norbert; Curty, Marcos

    2009-01-01

    Photon number resolving detectors can enhance the performance of many practical quantum cryptographic setups. In this paper, we employ a simple method to estimate the statistics provided by such a photon number resolving detector using only a threshold detector together with a variable attenuator. This idea is similar in spirit to that of the decoy state technique, and is especially suited to those scenarios where only a few parameters of the photon number statistics of the incoming signals have to be estimated. As an illustration of the potential applicability of the method in quantum communication protocols, we use it to prove security of an entanglement-based quantum key distribution scheme with an untrusted source without the need for a squash model and by solely using this extra idea. In this sense, this detector decoy method can be seen as a different conceptual approach to adapt a single-photon security proof to its physical, full optical implementation. We show that in this scenario, the legitimate users can now even discard the double click events from the raw key data without compromising the security of the scheme, and we present simulations on the performance of the BB84 and the 6-state quantum key distribution protocols.

  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. Application of Powell's analogy for the prediction of vortex-pairing sound in a low-Mach number jet based on time-resolved planar and tomographic PIV

    NARCIS (Netherlands)

    Violato, D.; Bryon, K.; Moore, P.; Scarano, F.

    2010-01-01

    This paper describes an experimental investigation by time-resolved planar and tomographic PIV on the sound production mechanism of vortex pairing of a transitional water-jet flow at Re=5000. The shear layer is characterized by axisymmetric vortex rings which undergo pairing with a varicose mode.

  9. HIBP primary beam detector

    International Nuclear Information System (INIS)

    Schmidt, T.W.

    1979-01-01

    A position measuring detector was fabricated for the Heavy Ion Beam Probe. The 11 cm by 50 cm detector was a combination of 15 detector wires in one direction and 63 copper bars - .635 cm by 10 cm to measure along an orthogonal axis by means of a current divider circuit. High transmission tungsten meshes provide entrance windows and suppress secondary electrons. The detector dimensions were chosen to resolve the beam position to within one beam diameter

  10. Enforcement actions: Significant actions resolved, material licensees. Semiannual progress report, July--December 1995: Volume 14, Numbers 3 and 4, Part 3

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-02-01

    This compilation summarizes significant enforcement actions that have been resolved during the period (July--December 1995) and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to material licensees with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication.

  11. Enforcement actions: Significant actions resolved, material licensees (non-medical). Quarterly progress report, July--September 1994: Volume 13, Number 3, Part 3

    International Nuclear Information System (INIS)

    1994-12-01

    This compilation summarizes significant enforcement actions that have been resolved during one quarterly period (July--September 1994) and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to material licensees (non-medical) with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated the managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication

  12. Enforcement actions: Significant actions resolved, reactor licensees. Semiannual progress report, July--December 1995. Volume 14, Numbers 3 and 4, Part 2

    International Nuclear Information System (INIS)

    1996-02-01

    This compilation summarizes significant enforcement actions that have been resolved during the period (July--December 1995) and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to reactor licensees with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication

  13. Enforcement actions: Significant actions resolved, material licensees. Semiannual progress report, July--December 1995: Volume 14, Numbers 3 and 4, Part 3

    International Nuclear Information System (INIS)

    1996-02-01

    This compilation summarizes significant enforcement actions that have been resolved during the period (July--December 1995) and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to material licensees with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication

  14. Material decomposition through weighted imaged subtraction in dual-energy spectral mammography with an energy-resolved photon-counting detector using Monte Carlo Simulation

    Energy Technology Data Exchange (ETDEWEB)

    Eom, Ji Soo; Kang, Soon Cheol; Lee, Seung Wan [Konyang University, Daejeon (Korea, Republic of)

    2017-09-15

    Mammography is commonly used for screening early breast cancer. However, mammographic images, which depend on the physical properties of breast components, are limited to provide information about whether a lesion is malignant or benign. Although a dual-energy subtraction technique decomposes a certain material from a mixture, it increases radiation dose and degrades the accuracy of material decomposition. In this study, we simulated a breast phantom using attenuation characteristics, and we proposed a technique to enable the accurate material decomposition by applying weighting factors for the dual-energy mammography based on a photon-counting detector using a Monte Carlo simulation tool. We also evaluated the contrast and noise of simulated breast images for validating the proposed technique. As a result, the contrast for a malignant tumor in the dual-energy weighted subtraction technique was 0.98 and 1.06 times similar than those in the general mammography and dual-energy subtraction techniques, respectively. However the contrast between malignant and benign tumors dramatically increased 13.54 times due to the low contrast of a benign tumor. Therefore, the proposed technique can increase the material decomposition accuracy for malignant tumor and improve the diagnostic accuracy of mammography.

  15. Technical Note: Modification of the standard gain correction algorithm to compensate for the number of used reference flat frames in detector performance studies

    International Nuclear Information System (INIS)

    Konstantinidis, Anastasios C.; Olivo, Alessandro; Speller, Robert D.

    2011-01-01

    Purpose: The x-ray performance evaluation of digital x-ray detectors is based on the calculation of the modulation transfer function (MTF), the noise power spectrum (NPS), and the resultant detective quantum efficiency (DQE). The flat images used for the extraction of the NPS should not contain any fixed pattern noise (FPN) to avoid contamination from nonstochastic processes. The ''gold standard'' method used for the reduction of the FPN (i.e., the different gain between pixels) in linear x-ray detectors is based on normalization with an average reference flat-field. However, the noise in the corrected image depends on the number of flat frames used for the average flat image. The aim of this study is to modify the standard gain correction algorithm to make it independent on the used reference flat frames. Methods: Many publications suggest the use of 10-16 reference flat frames, while other studies use higher numbers (e.g., 48 frames) to reduce the propagated noise from the average flat image. This study quantifies experimentally the effect of the number of used reference flat frames on the NPS and DQE values and appropriately modifies the gain correction algorithm to compensate for this effect. Results: It is shown that using the suggested gain correction algorithm a minimum number of reference flat frames (i.e., down to one frame) can be used to eliminate the FPN from the raw flat image. This saves computer memory and time during the x-ray performance evaluation. Conclusions: The authors show that the method presented in the study (a) leads to the maximum DQE value that one would have by using the conventional method and very large number of frames and (b) has been compared to an independent gain correction method based on the subtraction of flat-field images, leading to identical DQE values. They believe this provides robust validation of the proposed method.

  16. 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

  17. The Nustar Extragalactic Surveys: The Number Counts of Active Galactic Nuclei and the Resolved Fraction of the Cosmic X-Ray Background

    DEFF Research Database (Denmark)

    Harrison, F. A.; Aird, J.; Civano, F.

    2016-01-01

    . The measured NuSTAR counts lie significantly abovesimple extrapolation with a Euclidian slope to low flux of the Swift/BAT 15–55 keV number counts measured at higher fluxes (S(15–55 keV) ≤ 10−11 erg s-1 cm-2), reflecting the evolution of the AGN population between the Swift/BAT local (z ...STAR’s z ~ 1 sample. CXB synthesis models, which account for AGNevolution, lie above the Swift/BAT measurements, suggesting that they do not fully capture the evolution of obscured AGNs at low redshifts....... cm-2 ≤ 10-12, a factor ∼100 fainter than previous measurements. The 8–24 keV number counts match predictions from AGN populationsynthesis models, directly confirming the existence of a population of obscured and/or hard X-ray sources inferredfrom the shape of the integrated cosmic X-ray background...

  18. 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

  19. 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

  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.)

  1. Conditional preparation of states containing a definite number of photons

    International Nuclear Information System (INIS)

    O'Sullivan, Malcolm N.; Chan, Kam Wai Clifford; Boyd, Robert W.; Lakshminarayanan, Vasudevan

    2008-01-01

    A technique for conditionally creating single-mode or multimode photon-number states is analyzed using Bayesian theory. We consider the heralded N-photon states created from the photons produced by an unseeded optical parametric amplifier when the heralding detector is the time-multiplexed photon-number-resolving detector recently demonstrated by Fitch et al. [Phys. Rev. A 68, 043814 (2003)] and simultaneously by Achilles et al. [Opt. Lett. 28, 2387 (2003)]. We find that even with significant loss in the heralding detector, fields with sub-Poissonian photon-number distributions can be created. We also show that heralded multimode fields created using this technique are more robust against detector loss than are single-mode fields

  2. Observing Local Realism Violations with a Combination of Sensitive and Insensitive Detectors

    International Nuclear Information System (INIS)

    Yurke, B.; Stoler, D.

    1997-01-01

    Several systems are exhibited in which the establishment of local realism violation is achieved even when some of the detectors employed are insensitive. The insensitive detectors are homodyne detectors whose task is to determine if the amplitude of a coherent state is α or -α . This determination can be achieved with low quantum efficiency detectors when |α| is large. The other detectors employed determine whether there is an even number or an odd number of photons in a state. These detectors are sensitive since they are required to resolve the difference of one photon. For the examples given, the local realism violation is not diminished as |α| is increased. copyright 1997 The American Physical Society

  3. 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.

  4. Quantum dot single-photon switches of resonant tunneling current for discriminating-photon-number detection.

    Science.gov (United States)

    Weng, Qianchun; An, Zhenghua; Zhang, Bo; Chen, Pingping; Chen, Xiaoshuang; Zhu, Ziqiang; Lu, Wei

    2015-03-23

    Low-noise single-photon detectors that can resolve photon numbers are used to monitor the operation of quantum gates in linear-optical quantum computation. Exactly 0, 1 or 2 photons registered in a detector should be distinguished especially in long-distance quantum communication and quantum computation. Here we demonstrate a photon-number-resolving detector based on quantum dot coupled resonant tunneling diodes (QD-cRTD). Individual quantum-dots (QDs) coupled closely with adjacent quantum well (QW) of resonant tunneling diode operate as photon-gated switches- which turn on (off) the RTD tunneling current when they trap photon-generated holes (recombine with injected electrons). Proposed electron-injecting operation fills electrons into coupled QDs which turn "photon-switches" to "OFF" state and make the detector ready for multiple-photons detection. With proper decision regions defined, 1-photon and 2-photon states are resolved in 4.2 K with excellent propabilities of accuracy of 90% and 98% respectively. Further, by identifying step-like photon responses, the photon-number-resolving capability is sustained to 77 K, making the detector a promising candidate for advanced quantum information applications where photon-number-states should be accurately distinguished.

  5. Lepton detector workshop summary

    International Nuclear Information System (INIS)

    Imlay, R.; Iwata, S.; Thorndike, A.

    1976-01-01

    The study group met from June 7 to 11, 1976, with the dual purpose of reviewing an earlier Lepton Detector report in order to resolve some of the remaining design problems and of considering possible alternatives. Since the role of this group was primarily that of providing a critique of the earlier work, the reader is referred to that earlier paper for the general motivation and design of the detector. Problems studied at this session are described

  6. 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

  7. Difference in diaphragmatic motion during tidal breathing in a standing position between COPD patients and normal subjects: Time-resolved quantitative evaluation using dynamic chest radiography with flat panel detector system (“dynamic X-ray phrenicography”)

    International Nuclear Information System (INIS)

    Yamada, Yoshitake; Ueyama, Masako; Abe, Takehiko; Araki, Tetsuro; Abe, Takayuki; Nishino, Mizuki; Jinzaki, Masahiro; Hatabu, Hiroto

    2017-01-01

    Highlights: • Dynamic X-ray phrenicography is a useful method for the evaluation of the diaphragms. • Its radiation dose is comparable to conventional two projection chest radiography. • Diaphragm motion during tidal breathing is larger in COPD than in normal subjects. • Higher BMI is also associated with increased excursions of the bilateral diaphragm. - Abstract: Objectives: To quantitatively compare diaphragmatic motion during tidal breathing in a standing position between chronic obstructive pulmonary disease (COPD) patients and normal subjects using dynamic chest radiography. Materials and methods: Thirty-nine COPD patients (35 males; age, 71.3 ± 8.4 years) and 47 normal subjects (non-smoker healthy volunteers) (20 males; age, 54.8 ± 9.8 years) underwent sequential chest radiographs during tidal breathing using dynamic chest radiography with a flat panel detector system. We evaluated the excursions and peak motion speeds of the diaphragms. The results were analyzed using an unpaired t-test and a multiple linear regression model. Results: The excursions of the diaphragms in COPD patients were significantly larger than those in normal subjects (right, 14.7 ± 5.5 mm vs. 10.2 ± 3.7 mm, respectively, P < 0.001; left, 17.2 ± 4.9 mm vs. 14.9 ± 4.2 mm, respectively, P = 0.022). Peak motion speeds in inspiratory phase were significantly faster in COPD patients compared to normal subjects (right, 16.3 ± 5.0 mm/s vs. 11.8 ± 4.2 mm/s, respectively, P < 0.001; left, 18.9 ± 4.9 mm/s vs. 16.7 ± 4.0 mm/s, respectively, P = 0.022). The multivariate analysis demonstrated that having COPD and higher body mass index were independently associated with increased excursions of the bilateral diaphragm (all P < 0.05), after adjusting for other clinical variables. Conclusions: Time-resolved quantitative evaluation of the diaphragm using dynamic chest radiography demonstrated that the diaphragmatic motion during tidal breathing in a standing position is larger and

  8. Difference in diaphragmatic motion during tidal breathing in a standing position between COPD patients and normal subjects: Time-resolved quantitative evaluation using dynamic chest radiography with flat panel detector system (“dynamic X-ray phrenicography”)

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, Yoshitake, E-mail: yamada@rad.med.keio.ac.jp [Department of Radiology, Center for Pulmonary Functional Imaging, Brigham and Women’s Hospital, Harvard Medical School, 75 Francis St., Boston, MA 02215 (United States); Department of Diagnostic Radiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582 (Japan); Ueyama, Masako, E-mail: ueyamam@fukujuji.org [Department of Health Care, Fukujuji Hospital, Japan Anti-Tuberculosis Association, 3-1-24 Matsuyama, Kiyose, Tokyo 204-8522 (Japan); Abe, Takehiko, E-mail: takehikoabe@hotmail.com [Department of Radiology, Fukujuji Hospital, Japan Anti-Tuberculosis Association, 3-1-24 Matsuyama, Kiyose, Tokyo 204-8522 (Japan); Araki, Tetsuro, E-mail: TARAKI@partners.org [Department of Radiology, Center for Pulmonary Functional Imaging, Brigham and Women’s Hospital, Harvard Medical School, 75 Francis St., Boston, MA 02215 (United States); Abe, Takayuki, E-mail: abe.t@keio.jp [Department of Preventive Medicine and Public Health, Biostatistics Unit at Clinical and Translational Research Center, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582 (Japan); Nishino, Mizuki, E-mail: Mizuki_Nishino11@dfci.harvard.edu [Department of Radiology, Center for Pulmonary Functional Imaging, Brigham and Women’s Hospital, Harvard Medical School, 75 Francis St., Boston, MA 02215 (United States); Jinzaki, Masahiro, E-mail: jinzaki@rad.med.keio.ac.jp [Department of Diagnostic Radiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582 (Japan); Hatabu, Hiroto, E-mail: hhatabu@partners.org [Department of Radiology, Center for Pulmonary Functional Imaging, Brigham and Women’s Hospital, Harvard Medical School, 75 Francis St., Boston, MA 02215 (United States); and others

    2017-02-15

    Highlights: • Dynamic X-ray phrenicography is a useful method for the evaluation of the diaphragms. • Its radiation dose is comparable to conventional two projection chest radiography. • Diaphragm motion during tidal breathing is larger in COPD than in normal subjects. • Higher BMI is also associated with increased excursions of the bilateral diaphragm. - Abstract: Objectives: To quantitatively compare diaphragmatic motion during tidal breathing in a standing position between chronic obstructive pulmonary disease (COPD) patients and normal subjects using dynamic chest radiography. Materials and methods: Thirty-nine COPD patients (35 males; age, 71.3 ± 8.4 years) and 47 normal subjects (non-smoker healthy volunteers) (20 males; age, 54.8 ± 9.8 years) underwent sequential chest radiographs during tidal breathing using dynamic chest radiography with a flat panel detector system. We evaluated the excursions and peak motion speeds of the diaphragms. The results were analyzed using an unpaired t-test and a multiple linear regression model. Results: The excursions of the diaphragms in COPD patients were significantly larger than those in normal subjects (right, 14.7 ± 5.5 mm vs. 10.2 ± 3.7 mm, respectively, P < 0.001; left, 17.2 ± 4.9 mm vs. 14.9 ± 4.2 mm, respectively, P = 0.022). Peak motion speeds in inspiratory phase were significantly faster in COPD patients compared to normal subjects (right, 16.3 ± 5.0 mm/s vs. 11.8 ± 4.2 mm/s, respectively, P < 0.001; left, 18.9 ± 4.9 mm/s vs. 16.7 ± 4.0 mm/s, respectively, P = 0.022). The multivariate analysis demonstrated that having COPD and higher body mass index were independently associated with increased excursions of the bilateral diaphragm (all P < 0.05), after adjusting for other clinical variables. Conclusions: Time-resolved quantitative evaluation of the diaphragm using dynamic chest radiography demonstrated that the diaphragmatic motion during tidal breathing in a standing position is larger and

  9. Compound Semiconductor Radiation Detector

    International Nuclear Information System (INIS)

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

    2005-01-01

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

  10. Enzyme reactions and their time resolved measurements

    International Nuclear Information System (INIS)

    Hajdu, Janos

    1990-01-01

    This paper discusses experimental strategies in data collection with the Laue method and summarises recent results using synchrotron radiation. Then, an assessment is made of the progress towards time resolved studies with protein crystals and the problems that remain. The paper consists of three parts which respectively describe some aspects of Laue diffraction, recent examples of structural results from Laue diffraction, and kinetic Laue crystallography. In the first part, characteristics of Laue diffraction is discussed first, focusing on the harmonics problems, spatials problem, wavelength normalization, low resolution hole, data completeness, and uneven coverage of reciprocal space. Then, capture of the symmetry unique reflection set is discussed focusing on the effect of wavelength range on the number of reciprocal lattice points occupying diffracting positions, effect of crystal to film distance and the film area and shape on the number of reflections captured, and effect of crystal symmetry on the number of unique reflections within the number of reflections captured. The second part addresses the determination of the structure of turkey egg white lysozyme, and calcium binding in tomato bushy stunt virus. The third part describes the initiation of reactions in enzyme crystals, picosecond Laue diffraction at high energy storage rings, and detectors. (N.K.)

  11. Electrical engineering for the L* detector

    International Nuclear Information System (INIS)

    Alley, G.T.

    1991-01-01

    The Oak Ridge National Laboratory has been actively involved in detector R and D activities for the Superconducting Super Collider (SSC) for the past 2 years. During that time, the number of collaborative efforts with other institutions and the variety of topics being investigated have increased steadily. One of the most crucial areas of investigation has been related to the development of electronic systems that will gather and process the data emerging from the various detectors. The requirements being placed on these electronic 'readout' systems are staggering and at times conflicting. The number of data channels projected for a typical SSC detector system is greater than 1 million. Data may be available from the detector every 16 ns; this means that the readout electronics must be capable of responding to this very fast data rate. To compound the issue, heat dissipation will be a severe problem because of the sheer density of electronics needed for readout of millions of channels. Yet another concern is the hostile radiation environment to which the electronics will be subjected. It has been estimated that the accumulated dose seen by the electronic readout systems will be from 10 to 100 Mrads over the lifetime of the detector, depending on the location within the detector. Obviously, there are serious tradeoff issues that must be resolved. One of the major electronics R and D activities at ORNL is related to the Hybrid Central Tracking subsystem. This central tracking subsystem is a candidate for the Solenoidal Detector Collaboration. The Hybrid Central Tracker gets its name because it is a hybrid arrangement of concentric layers of strawtube drift chambers and scintillating fibers. The work at ORNL has been targeted primarily toward electronics development for strawtube readout

  12. Characterization and first experimental application of space-resolving, energy-dispersive germanium detectors for the precision spectroscopy on heavy ions; Charakterisierung und erster experimenteller Einsatz von ortsaufloesenden, energiedispersiven Germanium-Detektoren zur Praezisionsspektroskopie an schweren Ionen

    Energy Technology Data Exchange (ETDEWEB)

    Spillmann, Uwe

    2009-02-15

    First the actual status of the research for the 1s Lamb shift on heaviest systems as well as studies on the polarization of the radiative recombination radiation into the K shell of uranium are presented. On this base future precision experiments at storage rings are discussed. then follows a survey presentation of the GSI accelerator facility. Especially the experimental storage ring ESR is described, at which the experiments mentioned above were performed. Then an introduction to the fundamental understanding of the physical processes in the detection of X-radiation in semiconductor detectors is given. The following chapter discusses the detection technique of the Compton polarimetry and some experimental concepts for this. Then by means of a 4 x 4 pixel Ge(i) detector system, by which for the first time the K-REC radiation from uranium was measured at the ESR, an overview about the Monte-Carlo software EGS4 is given, which was applied to the efficiency correction in the evaluation phase and for the estimation of the detector behaviour during the planning phase of the new detectors. A presentation of the 1D and 2D microstrip detector system as well as the performed laboratory measurements follows. The results for the characterization of the 2D microstrip detector system at the synchrotron-radiation source ESRF in view of its application with the FOCAL spectrometer are thereafter described. The results of first test measurement on the Compton polarimetry, which were also performed at the ESRF, are then presented. Finally first experimental results, which wer obtained by the novel planar structured Ge(i) detectors, are shown.

  13. Neutron detector

    Science.gov (United States)

    Stephan, Andrew C [Knoxville, TN; Jardret,; Vincent, D [Powell, TN

    2011-04-05

    A neutron detector has a volume of neutron moderating material and a plurality of individual neutron sensing elements dispersed at selected locations throughout the moderator, and particularly arranged so that some of the detecting elements are closer to the surface of the moderator assembly and others are more deeply embedded. The arrangement captures some thermalized neutrons that might otherwise be scattered away from a single, centrally located detector element. Different geometrical arrangements may be used while preserving its fundamental characteristics. Different types of neutron sensing elements may be used, which may operate on any of a number of physical principles to perform the function of sensing a neutron, either by a capture or a scattering reaction, and converting that reaction to a detectable signal. High detection efficiency, an ability to acquire spectral information, and directional sensitivity may be obtained.

  14. 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)

  15. Minimum resolvable power contrast model

    Science.gov (United States)

    Qian, Shuai; Wang, Xia; Zhou, Jingjing

    2018-01-01

    Signal-to-noise ratio and MTF are important indexs to evaluate the performance of optical systems. However,whether they are used alone or joint assessment cannot intuitively describe the overall performance of the system. Therefore, an index is proposed to reflect the comprehensive system performance-Minimum Resolvable Radiation Performance Contrast (MRP) model. MRP is an evaluation model without human eyes. It starts from the radiance of the target and the background, transforms the target and background into the equivalent strips,and considers attenuation of the atmosphere, the optical imaging system, and the detector. Combining with the signal-to-noise ratio and the MTF, the Minimum Resolvable Radiation Performance Contrast is obtained. Finally the detection probability model of MRP is given.

  16. High-energy detector

    Science.gov (United States)

    Bolotnikov, Aleksey E [South Setauket, NY; Camarda, Giuseppe [Farmingville, NY; Cui, Yonggang [Upton, NY; James, Ralph B [Ridge, NY

    2011-11-22

    The preferred embodiments are directed to a high-energy detector that is electrically shielded using an anode, a cathode, and a conducting shield to substantially reduce or eliminate electrically unshielded area. The anode and the cathode are disposed at opposite ends of the detector and the conducting shield substantially surrounds at least a portion of the longitudinal surface of the detector. The conducting shield extends longitudinally to the anode end of the detector and substantially surrounds at least a portion of the detector. Signals read from one or more of the anode, cathode, and conducting shield can be used to determine the number of electrons that are liberated as a result of high-energy particles impinge on the detector. A correction technique can be implemented to correct for liberated electron that become trapped to improve the energy resolution of the high-energy detectors disclosed herein.

  17. 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.)

  18. Detectors and flux instrumentation for future neutrino facilities

    CERN Document Server

    Abe, T.; Andreopoulos, C.; Ankowski, A.; Badertscher, A.; Battistoni, G.; Blondel, A.; Bouchez, J.; Bross, A.; Bueno, A.; Camilleri, L.; Campagne, Jean-Eric; Cazes, A.; Cervera-Villanueva, A.; De Lellis, G.; Di Capua, F.; Ellis, Malcolm; Ereditato, A.; Esposito, L.S.; Fukushima, C.; Gschwendtner, E.; Gomez-Cadenas, J.J.; Iwasaki, M.; Kaneyuki, K.; Karadzhov, Y.; Kashikhin, V.; Kawai, Y.; Komatsu, M.; Kozlovskaya, E.; Kudenko, Y.; Kusaka, A.; Kyushima, H.; Longhin, A.; Marchionni, A.; Marotta, A.; McGrew, C.; Menary, S.; Meregaglia, A.; Mezzeto, M.; Migliozzi, P.; Mondal, N.K.; Montanari, C.; Nakadaira, T.; Nakamura, M.; Nakumo, H.; Nakayama, H.; Nelson, J.; Nowak, J.; Ogawa, S.; Peltoniemi, J.; Pla-Dalmau, A.; Ragazzi, S.; Rubbia, A.; Sanchez, F.; Sarkamo, J.; Sato, O.; Selvi, M.; Shibuya, H.; Shozawa, M.; Sobczyk, J.; Soler, F.J.P.; Strolin, Paolo Emilio; Suyama, M.; Tanak, M.; Terranova, F.; Tsenov, R.; Uchida, Y.; Weber, A.; Zlobin, A.

    2009-01-01

    This report summarises the conclusions from the detector group of the International Scoping Study of a future Neutrino Factory and Super-Beam neutrino facility. The baseline detector options for each possible neutrino beam are defined as follows: 1. A very massive (Megaton) water Cherenkov detector is the baseline option for a sub-GeV Beta Beam and Super Beam facility. 2. There are a number of possibilities for either a Beta Beam or Super Beam (SB) medium energy facility between 1-5 GeV. These include a totally active scintillating detector (TASD), a liquid argon TPC or a water Cherenkov detector. 3. A 100 kton magnetized iron neutrino detector (MIND) is the baseline to detect the wrong sign muon final states (golden channel) at a high energy (20-50 GeV) neutrino factory from muon decay. A 10 kton hybrid neutrino magnetic emulsion cloud chamber detector for wrong sign tau detection (silver channel) is a possible complement to MIND, if one needs to resolve degeneracies that appear in the $\\delta$-$\\theta_{13}$...

  19. A quartz Cherenkov detector for Compton-polarimetry at future e+e- colliders

    International Nuclear Information System (INIS)

    List, Jenny; Vauth, Annika; Vormwald, Benedikt; Hamburg Univ.

    2015-02-01

    Precision polarimetry is essential for future e + e - colliders and requires Compton polarimeters designed for negligible statistical uncertainties. In this paper, we discuss the design and construction of a quartz Cherenkov detector for such Compton polarimeters. The detector concept has been developed with regard to the main systematic uncertainties of the polarisation measurements, namely the linearity of the detector response and detector alignment. Simulation studies presented here imply that the light yield reachable by using quartz as Cherenkov medium allows to resolve in the Cherenkov photon spectra individual peaks corresponding to different numbers of Compton electrons. The benefits of the application of a detector with such single-peak resolution to the polarisation measurement are shown for the example of the upstream polarimeters foreseen at the International Linear Collider. Results of a first testbeam campaign with a four-channel prototype confirming simulation predictions for single electrons are presented.

  20. Neutron and X-ray Detectors

    Energy Technology Data Exchange (ETDEWEB)

    Carini, Gabriella [SLAC National Accelerator Lab., Menlo Park, CA (United States); Denes, Peter [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Gruener, Sol [Cornell Univ., Ithaca, NY (United States); Lessner, Elianne [Dept. of Energy (DOE), Washington DC (United States). Office of Science Office of Basic Energy Sciences

    2012-08-01

    (and two computing hurdles that result from the corresponding increase in data volume) for the detector community to overcome in order to realize the full potential of BES neutron and X-ray facilities. Resolving these detector impediments will improve scientific productivity both by enabling new types of experiments, which will expand the scientific breadth at the X-ray and neutron facilities, and by potentially reducing the beam time required for a given experiment. These research priorities are summarized in the table below. Note that multiple, simultaneous detector improvements are often required to take full advantage of brighter sources. High-efficiency hard X-ray sensors: The fraction of incident particles that are actually detected defines detector efficiency. Silicon, the most common direct-detection X-ray sensor material, is (for typical sensor thicknesses) 100% efficient at 8 keV, 25%efficient at 20 keV, and only 3% efficient at 50 keV. Other materials are needed for hard X-rays. Replacement for 3He for neutron detectors: 3He has long been the neutron detection medium of choice because of its high cross section over a wide neutron energy range for the reaction 3He + n —> 3H + 1H + 0.764 MeV. 3He stockpiles are rapidly dwindling, and what is available can be had only at prohibitively high prices. Doped scintillators hold promise as ways to capture neutrons and convert them into light, although work is needed on brighter, more efficient scintillator solutions. Neutron detectors also require advances in speed and resolution. Fast-framing X-ray detectors: Today’s brighter X-ray sources make time-resolved studies possible. For example, hybrid X-ray pixel detectors, initially developed for particle physics, are becoming fairly mature X-ray detectors, with considerable development in Europe. To truly enable time-resolved studies, higher frame rates and dynamic range are required, and smaller pixel sizes are desirable. High-speed spectroscopic X-ray detectors

  1. Detector response artefacts in spectral reconstruction

    DEFF Research Database (Denmark)

    Olsen, Ulrik Lund; Christensen, Erik D.; Khalil, Mohamad

    2017-01-01

    Energy resolved detectors are gaining traction as a tool to achieve better material contrast. K-edge imaging and tomography is an example of a method with high potential that has evolved on the capabilities of photon counting energy dispersive detectors. Border security is also beginning to see...... instruments taking advantage of energy resolved detectors. The progress of the field is halted by the limitations of the detectors. The limitations include nonlinear response for both x-ray intensity and x-ray spectrum. In this work we investigate how the physical interactions in the energy dispersive...

  2. 3D silicon strip detectors

    International Nuclear Information System (INIS)

    Parzefall, Ulrich; Bates, Richard; Boscardin, Maurizio; Dalla Betta, Gian-Franco; Eckert, Simon; Eklund, Lars; Fleta, Celeste; Jakobs, Karl; Kuehn, Susanne; Lozano, Manuel; Pahn, Gregor; Parkes, Chris; Pellegrini, Giulio; Pennicard, David; Piemonte, Claudio; Ronchin, Sabina; Szumlak, Tomasz; Zoboli, Andrea; Zorzi, Nicola

    2009-01-01

    While the Large Hadron Collider (LHC) at CERN has started operation in autumn 2008, plans for a luminosity upgrade to the Super-LHC (sLHC) have already been developed for several years. This projected luminosity increase by an order of magnitude gives rise to a challenging radiation environment for tracking detectors at the LHC experiments. Significant improvements in radiation hardness are required with respect to the LHC. Using a strawman layout for the new tracker of the ATLAS experiment as an example, silicon strip detectors (SSDs) with short strips of 2-3 cm length are foreseen to cover the region from 28 to 60 cm distance to the beam. These SSD will be exposed to radiation levels up to 10 15 N eq /cm 2 , which makes radiation resistance a major concern for the upgraded ATLAS tracker. Several approaches to increasing the radiation hardness of silicon detectors exist. In this article, it is proposed to combine the radiation hard 3D-design originally conceived for pixel-style applications with the benefits of the established planar technology for strip detectors by using SSDs that have regularly spaced doped columns extending into the silicon bulk under the detector strips. The first 3D SSDs to become available for testing were made in the Single Type Column (STC) design, a technological simplification of the original 3D design. With such 3D SSDs, a small number of prototype sLHC detector modules with LHC-speed front-end electronics as used in the semiconductor tracking systems of present LHC experiments were built. Modules were tested before and after irradiation to fluences of 10 15 N eq /cm 2 . The tests were performed with three systems: a highly focused IR-laser with 5μm spot size to make position-resolved scans of the charge collection efficiency, an Sr 90 β-source set-up to measure the signal levels for a minimum ionizing particle (MIP), and a beam test with 180 GeV pions at CERN. This article gives a brief overview of the results obtained with 3D-STC-modules.

  3. 3D silicon strip detectors

    Energy Technology Data Exchange (ETDEWEB)

    Parzefall, Ulrich [Physikalisches Institut, Universitaet Freiburg, Hermann-Herder-Str. 3, D-79104 Freiburg (Germany)], E-mail: ulrich.parzefall@physik.uni-freiburg.de; Bates, Richard [University of Glasgow, Department of Physics and Astronomy, Glasgow G12 8QQ (United Kingdom); Boscardin, Maurizio [FBK-irst, Center for Materials and Microsystems, via Sommarive 18, 38050 Povo di Trento (Italy); Dalla Betta, Gian-Franco [INFN and Universita' di Trento, via Sommarive 14, 38050 Povo di Trento (Italy); Eckert, Simon [Physikalisches Institut, Universitaet Freiburg, Hermann-Herder-Str. 3, D-79104 Freiburg (Germany); Eklund, Lars; Fleta, Celeste [University of Glasgow, Department of Physics and Astronomy, Glasgow G12 8QQ (United Kingdom); Jakobs, Karl; Kuehn, Susanne [Physikalisches Institut, Universitaet Freiburg, Hermann-Herder-Str. 3, D-79104 Freiburg (Germany); Lozano, Manuel [Instituto de Microelectronica de Barcelona, IMB-CNM, CSIC, Barcelona (Spain); Pahn, Gregor [Physikalisches Institut, Universitaet Freiburg, Hermann-Herder-Str. 3, D-79104 Freiburg (Germany); Parkes, Chris [University of Glasgow, Department of Physics and Astronomy, Glasgow G12 8QQ (United Kingdom); Pellegrini, Giulio [Instituto de Microelectronica de Barcelona, IMB-CNM, CSIC, Barcelona (Spain); Pennicard, David [University of Glasgow, Department of Physics and Astronomy, Glasgow G12 8QQ (United Kingdom); Piemonte, Claudio; Ronchin, Sabina [FBK-irst, Center for Materials and Microsystems, via Sommarive 18, 38050 Povo di Trento (Italy); Szumlak, Tomasz [University of Glasgow, Department of Physics and Astronomy, Glasgow G12 8QQ (United Kingdom); Zoboli, Andrea [INFN and Universita' di Trento, via Sommarive 14, 38050 Povo di Trento (Italy); Zorzi, Nicola [FBK-irst, Center for Materials and Microsystems, via Sommarive 18, 38050 Povo di Trento (Italy)

    2009-06-01

    While the Large Hadron Collider (LHC) at CERN has started operation in autumn 2008, plans for a luminosity upgrade to the Super-LHC (sLHC) have already been developed for several years. This projected luminosity increase by an order of magnitude gives rise to a challenging radiation environment for tracking detectors at the LHC experiments. Significant improvements in radiation hardness are required with respect to the LHC. Using a strawman layout for the new tracker of the ATLAS experiment as an example, silicon strip detectors (SSDs) with short strips of 2-3 cm length are foreseen to cover the region from 28 to 60 cm distance to the beam. These SSD will be exposed to radiation levels up to 10{sup 15}N{sub eq}/cm{sup 2}, which makes radiation resistance a major concern for the upgraded ATLAS tracker. Several approaches to increasing the radiation hardness of silicon detectors exist. In this article, it is proposed to combine the radiation hard 3D-design originally conceived for pixel-style applications with the benefits of the established planar technology for strip detectors by using SSDs that have regularly spaced doped columns extending into the silicon bulk under the detector strips. The first 3D SSDs to become available for testing were made in the Single Type Column (STC) design, a technological simplification of the original 3D design. With such 3D SSDs, a small number of prototype sLHC detector modules with LHC-speed front-end electronics as used in the semiconductor tracking systems of present LHC experiments were built. Modules were tested before and after irradiation to fluences of 10{sup 15}N{sub eq}/cm{sup 2}. The tests were performed with three systems: a highly focused IR-laser with 5{mu}m spot size to make position-resolved scans of the charge collection efficiency, an Sr{sup 90}{beta}-source set-up to measure the signal levels for a minimum ionizing particle (MIP), and a beam test with 180 GeV pions at CERN. This article gives a brief overview of

  4. Enforcement actions: Significant actions resolved

    International Nuclear Information System (INIS)

    1990-05-01

    This compilation summarizes significant enforcement actions that have been resolved during one quarterly period (January--March 1990) and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to licensees with respect to these enforcement actions. Also included are a number of enforcement actions that had been previously resolved but not published in this NUREG. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication

  5. Enforcement actions: Significant actions resolved

    International Nuclear Information System (INIS)

    1989-06-01

    This compilation summarizes significant enforcement actions that have been resolved during one quarterly period (January--March 1989) and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to licensees with respect to these enforcement actions. Also included are a number of enforcement actions that had been previously resolved but not published in this NUREG. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication

  6. 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.

  7. 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.

  8. Summary of activity. Topic I: detectors and experiments. [High-energy detectors for use at ISABELLE

    Energy Technology Data Exchange (ETDEWEB)

    Marx, J; Ozaki, S

    1978-01-01

    Results of a workshop studying detectors for Isabelle experimental halls are described. The detectors must be very reliable. Spatial resolution of the tracking detectors must be high to provide accurate measurements of angle and momentum, retain a short resolving time, and show excellent multiparticle handling capability. Included in the study were hodoscopes, drift chambers, proportional chambers, time projection chambers, Cherenkov counters, electromagnetic shower detectors, and hadron calorimeters. Data handling methods were also included in the studies. (FS)

  9. The status of BAT detector

    Science.gov (United States)

    Lien, Amy; Markwardt, Craig B.; Krimm, Hans Albert; Barthelmy, Scott D.; Cenko, Bradley

    2018-01-01

    We will present the current status of the Swift/BAT detector. In particular, we will report the updated detector gain calibration, the number of enable detectors, and the global bad time intervals with potential calibration issues. We will also summarize the results of the yearly BAT calibration using the Crab nebula. Finally, we will discuss the effects on the BAT survey, such as the sensitivity, localization, and spectral analysis, due to the changes in detector status.

  10. NEW LENSLET BASED IFS WITH HIGH DETECTOR PIXEL EFFICIENCY

    Science.gov (United States)

    Gong, Qian

    2018-01-01

    Three IFS types currently used for optical design are: lenslet array, imager slicer, and lenslet array and fiber combined. Lenslet array based Integral Field Spectroscopy (IFS) is very popular for many astrophysics applications due to its compactness, simplicity, as well as cost and mass savings. The disadvantage of lenslet based IFS is its low detector pixel efficiency. Enough spacing is needed between adjacent spectral traces in cross dispersion direction to avoid wavelength cross-talk, because the same wavelength is not aligned to the same column on detector. Such as on a recent exoplanet coronagraph instrument study to support the coming astrophysics decadal survey (LUVOIR), to cover a 45 λ/D Field of View (FOV) with a spectral resolving power of 200 at shortest wavelength, a 4k x 4k detector array is needed. This large format EMCCD pushes the detector into technology development area with a low TRL. Besides the future mission, it will help WFIRST coronagraph IFS by packing all spectra into a smaller area on detector, which will reduce the chance for electrons to be trapped in pixels, and slow the detector degradation during the mission.The innovation we propose here is to increase the detector packing efficiency by grouping a number of lenslets together to form many mini slits. In other words, a number of spots (Point Spread Function at lenslet focus) are aligned into a line to resemble a mini slit. Therefore, wavelength cross-talk is no longer a concern anymore. This combines the advantage of lenslet array and imager slicer together. The isolation rows between spectral traces in cross dispersion direction can be reduced or removed. So the packing efficiency is greatly increased. Furthermore, the today’s microlithography and etching technique is capable of making such a lenslet array, which will relax the detector demand significantly. It will finally contribute to the habitable exoplanets study to analyzing their spectra from direct images. Detailed theory

  11. Practical photon number detection with electric field-modulated silicon avalanche photodiodes.

    Science.gov (United States)

    Thomas, O; Yuan, Z L; Shields, A J

    2012-01-24

    Low-noise single-photon detection is a prerequisite for quantum information processing using photonic qubits. In particular, detectors that are able to accurately resolve the number of photons in an incident light pulse will find application in functions such as quantum teleportation and linear optics quantum computing. More generally, such a detector will allow the advantages of quantum light detection to be extended to stronger optical signals, permitting optical measurements limited only by fluctuations in the photon number of the source. Here we demonstrate a practical high-speed device, which allows the signals arising from multiple photon-induced avalanches to be precisely discriminated. We use a type of silicon avalanche photodiode in which the lateral electric field profile is strongly modulated in order to realize a spatially multiplexed detector. Clearly discerned multiphoton signals are obtained by applying sub-nanosecond voltage gates in order to restrict the detector current.

  12. 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.

  13. 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).

  14. Chromatographic background drift correction coupled with parallel factor analysis to resolve coelution problems in three-dimensional chromatographic data: quantification of eleven antibiotics in tap water samples by high-performance liquid chromatography coupled with a diode array detector.

    Science.gov (United States)

    Yu, Yong-Jie; Wu, Hai-Long; Fu, Hai-Yan; Zhao, Juan; Li, Yuan-Na; Li, Shu-Fang; Kang, Chao; Yu, Ru-Qin

    2013-08-09

    Chromatographic background drift correction has been an important field of research in chromatographic analysis. In the present work, orthogonal spectral space projection for background drift correction of three-dimensional chromatographic data was described in detail and combined with parallel factor analysis (PARAFAC) to resolve overlapped chromatographic peaks and obtain the second-order advantage. This strategy was verified by simulated chromatographic data and afforded significant improvement in quantitative results. Finally, this strategy was successfully utilized to quantify eleven antibiotics in tap water samples. Compared with the traditional methodology of introducing excessive factors for the PARAFAC model to eliminate the effect of background drift, clear improvement in the quantitative performance of PARAFAC was observed after background drift correction by orthogonal spectral space projection. Copyright © 2013 Elsevier B.V. All rights reserved.

  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. Numerical optimisation in spot detector design

    NARCIS (Netherlands)

    van der Heijden, Ferdinand; Apperloo, W.; Spreeuwers, Lieuwe Jan

    1997-01-01

    Spots are image details resulting from objects, the projections of which are so small that the inner structure of these objects cannot be resolved from their image. Spot detectors are image operators aiming at the detection and localisation of spots in the image. Most spot detectors can be tuned

  17. 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

  18. The influence of the number of activation detectors on the Seibersdorf - Milano intercomparison of neutron flux density spectra by WINDOWS code

    International Nuclear Information System (INIS)

    Ertek, C.

    1981-02-01

    This work is a continuation of the work performed within the IAEA programme on standardization of reactor radiation measurements, one of the important objectives of which is the assistance to laboratories in Member States to implement or intercompare the multiple foil activation techniques for different neutron field measurements. The importance of these techniques is well recognized. In CESNEF-FERMI Politecnico di Milano, Italy, they have installed near the core of a water boiler of 50kW, a neutron filter made of B 4 C in order to obtain a neutron flux density spectrum that could be of utility in intercalibration problems connected with irradiation in fast assemblies. Dr. V. Sangiust from CESNEF kindly sent the input guess neutron flux density spectrum and a series of measured reaction rates to be treated by the IAEA Seibersdorf laboratory using the SAND-II and the WINDOWS unfolding codes. The meaningful comparison using partly the same ENDF/B IV cross section data is performed. In the present work we extended the investiga tion using WINDOWS unfolding code for different numbers of activation fo ils or reaction rates

  19. Simulation study of pixel detector charge digitization

    Science.gov (United States)

    Wang, Fuyue; Nachman, Benjamin; Sciveres, Maurice; Lawrence Berkeley National Laboratory Team

    2017-01-01

    Reconstruction of tracks from nearly overlapping particles, called Tracking in Dense Environments (TIDE), is an increasingly important component of many physics analyses at the Large Hadron Collider as signatures involving highly boosted jets are investigated. TIDE makes use of the charge distribution inside a pixel cluster to resolve tracks that share one of more of their pixel detector hits. In practice, the pixel charge is discretized using the Time-over-Threshold (ToT) technique. More charge information is better for discrimination, but more challenging for designing and operating the detector. A model of the silicon pixels has been developed in order to study the impact of the precision of the digitized charge distribution on distinguishing multi-particle clusters. The output of the GEANT4-based simulation is used to train neutral networks that predict the multiplicity and location of particles depositing energy inside one cluster of pixels. By studying the multi-particle cluster identification efficiency and position resolution, we quantify the trade-off between the number of ToT bits and low-level tracking inputs. As both ATLAS and CMS are designing upgraded detectors, this work provides guidance for the pixel module designs to meet TIDE needs. Work funded by the China Scholarship Council and the Office of High Energy Physics of the U.S. Department of Energy under contract DE-AC02-05CH11231.

  20. Time-Resolved Quantitative Analysis of the Diaphragms During Tidal Breathing in a Standing Position Using Dynamic Chest Radiography with a Flat Panel Detector System ("Dynamic X-Ray Phrenicography"): Initial Experience in 172 Volunteers.

    Science.gov (United States)

    Yamada, Yoshitake; Ueyama, Masako; Abe, Takehiko; Araki, Tetsuro; Abe, Takayuki; Nishino, Mizuki; Jinzaki, Masahiro; Hatabu, Hiroto; Kudoh, Shoji

    2017-04-01

    Diaphragmatic motion in a standing position during tidal breathing remains unclear. The purpose of this observational study was to evaluate diaphragmatic motion during tidal breathing in a standing position in a health screening center cohort using dynamic chest radiography in association with participants' demographic characteristics. One hundred seventy-two subjects (103 men; aged 56.3 ± 9.8 years) underwent sequential chest radiographs during tidal breathing using dynamic chest radiography with a flat panel detector system. We evaluated the excursions of and peak motion speeds of the diaphragms. Associations between the excursions and participants' demographics (gender, height, weight, body mass index [BMI], smoking history, tidal volume, vital capacity, and forced expiratory volume) were investigated. The average excursion of the left diaphragm (14.9 ± 4.6 mm, 95% CI 14.2-15.5 mm) was significantly larger than that of the right (11.0 ± 4.0 mm, 95% CI 10.4-11.6 mm) (P <0.001). The peak motion speed of the left diaphragm (inspiratory, 16.6 ± 4.2 mm/s; expiratory, 13.7 ± 4.2 mm/s) was significantly faster than that of the right (inspiratory, 12.4 ± 4.4 mm/s; expiratory, 9.4 ± 3.8 mm/s) (both P <0.001). Both simple and multiple regression models demonstrated that higher BMI and higher tidal volume were associated with increased excursions of the bilateral diaphragm (all P <0.05). The average excursions of the diaphragms are 11.0 mm (right) and 14.9 mm (left) during tidal breathing in a standing position. The diaphragmatic motion of the left is significantly larger and faster than that of the right. Higher BMI and tidal volume are associated with increased excursions of the bilateral diaphragm. Copyright © 2017 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

  1. ACCESS: Detector Control and Performance

    Science.gov (United States)

    Morris, Matthew J.; Kaiser, M.; McCandliss, S. R.; Rauscher, B. J.; Kimble, R. A.; Kruk, J. W.; Wright, E. L.; Bohlin, R.; Kurucz, R. L.; Riess, A. G.; Pelton, R.; Deustua, S. E.; Dixon, W. V.; Sahnow, D. J.; Mott, D. B.; Wen, Y.; Benford, D. J.; Gardner, J. P.; Feldman, P. D.; Moos, H. W.; Lampton, M.; Perlmutter, S.; Woodgate, B. E.

    2014-01-01

    ACCESS, Absolute Color Calibration Experiment for Standard Stars, is a series of rocket-borne sub-orbital missions and ground-based experiments that will enable improvements in the precision of the astrophysical flux scale through the transfer of absolute laboratory detector standards from the National Institute of Standards and Technology (NIST) to a network of stellar standards with a calibration accuracy of 1% and a spectral resolving power of 500 across the 0.35 to 1.7 micron bandpass (companion poster, Kaiser et al.). The flight detector and detector spare have been selected and integrated with their electronics and flight mount. The controller electronics have been flight qualified. Vibration testing to launch loads and thermal vacuum testing of the detector, mount, and housing have been successfully performed. Further improvements to the flight controller housing have been made. A cryogenic ground test system has been built. Dark current and read noise tests have been performed, yielding results consistent with the initial characterization tests of the detector performed by Goddard Space Flight Center’s Detector Characterization Lab (DCL). Detector control software has been developed and implemented for ground testing. Performance and integration of the detector and controller with the flight software will be presented. NASA APRA sounding rocket grant NNX08AI65G supports this work.

  2. Developments in time-resolved high pressure x-ray diffraction using rapid compression and decompression

    International Nuclear Information System (INIS)

    Smith, Jesse S.; Sinogeikin, Stanislav V.; Lin, Chuanlong; Rod, Eric; Bai, Ligang; Shen, Guoyin

    2015-01-01

    Complementary advances in high pressure research apparatus and techniques make it possible to carry out time-resolved high pressure research using what would customarily be considered static high pressure apparatus. This work specifically explores time-resolved high pressure x-ray diffraction with rapid compression and/or decompression of a sample in a diamond anvil cell. Key aspects of the synchrotron beamline and ancillary equipment are presented, including source considerations, rapid (de)compression apparatus, high frequency imaging detectors, and software suitable for processing large volumes of data. A number of examples are presented, including fast equation of state measurements, compression rate dependent synthesis of metastable states in silicon and germanium, and ultrahigh compression rates using a piezoelectric driven diamond anvil cell

  3. 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

  4. The SISWICH, a detector telescope with intrinsic calibration

    International Nuclear Information System (INIS)

    Friese, J.; Gillitzer, A.; Koerener, H.J.; Reinhold, J.; Peter, M.; Maier, M.R.

    1992-10-01

    Phoswich counters have gained widespread popularity as detectors for medium energy charged particles. They provide adequate energy resolution and particle identification up to atomic numbers Z = 20. However, the question of calibration has not been resolved satisfactorily. To overcome this difficulty we have built a Silicon-Scintillator SandWICH (SISWICH). This detector consists of a silicon PIN photo diode glued to the front of a CsI (T ell) scintillator crystal. The signal coming from the PIN diode contains the energy loss of the particle in the silicon, which is fast (nuclear counter effect), and the light output of the scintillator which is slow. The component coming from the nuclear counter effect can be calibrated with a pulser. Therefore, since the energy loss of a particle with known Z has been measured, its energy is known, and this can be used to calibrate the signal from the scintillator. Results will be shown

  5. 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

  6. 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.)

  7. Summary of activity. Topic I: detectors and experiments

    International Nuclear Information System (INIS)

    Marx, J.; Ozaki, S.

    Results of a workshop studying detectors for Isabelle experimental halls are described. The detectors must be very reliable. Spatial resolution of the tracking detectors must be high to provide accurate measurements of angle and momentum, retain a short resolving time, and show excellent multiparticle handling capability. Included in the study were hodoscopes, drift chambers, proportional chambers, time projection chambers, Cherenkov counters, electromagnetic shower detectors, and hadron calorimeters. Data handling methods were also included in the studies

  8. SoLid Detector Technology

    Science.gov (United States)

    Labare, Mathieu

    2017-09-01

    SoLid is a reactor anti-neutrino experiment where a novel detector is deployed at a minimum distance of 5.5 m from a nuclear reactor core. The purpose of the experiment is three-fold: to search for neutrino oscillations at a very short baseline; to measure the pure 235U neutrino energy spectrum; and to demonstrate the feasibility of neutrino detectors for reactor monitoring. This report presents the unique features of the SoLid detector technology. The technology has been optimised for a high background environment resulting from low overburden and the vicinity of a nuclear reactor. The versatility of the detector technology is demonstrated with a 288 kg detector prototype which was deployed at the BR2 nuclear reactor in 2015. The data presented includes both reactor on, reactor off and calibration measurements. The measurement results are compared with Monte Carlo simulations. The 1.6t SoLid detector is currently under construction, with an optimised design and upgraded material technology to enhance the detector capabilities. Its deployement on site is planned for the begin of 2017 and offers the prospect to resolve the reactor anomaly within about two years.

  9. Detectors for CBA

    International Nuclear Information System (INIS)

    Baggett, N.; Gordon, H.A.; Palmer, R.B.; Tannenbaum, M.J.

    1983-05-01

    We discuss some current approaches to a large solid angle detector. An alternative approach for utilizing the high rate of events at CBA is to design special purpose detectors for specific physics goals which can be pursued within a limited solid angle. In many cases this will be the only way to proceed, and then high luminosity has a different significance. The total rate in the restricted acceptance is less likely to be a problem, while the need for high luminosity to obtain sufficient data is obvious. Eight such experiments from studies carried out in the community are surveyed. Such experiments could be run on their own or in combination with others at the same intersection, or even with a large solid angle detector, if a window can be provided in the larger facility. The small solid angle detector would provide the trigger and special information, while the facility would provide back-up information on the rest of the event. We consider some possibilities of refurbishing existing detectors for use at CBA. This discussion is motivated by the fact that there is a growing number of powerful detectors at colliding beam machines around the world. Their builders have invested considerable amounts of time, money and ingenuity in them, and may wish to extend the useful lives of their creations, as new opportunities arise

  10. 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.

  11. 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

  12. 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

  13. Operation: Inherent Resolve

    DEFF Research Database (Denmark)

    Cramer-Larsen, Lars

    2015-01-01

    Kapitlet giver læseren indsigt i den internationale koalitions engagement mod IS igennem Operaton Inherent Resolve; herunder koalitionens strategi i forhold til IS strategi, ligesom det belyser kampagnens legalitet og folkeretlige grundlag, ligesom det giver et bud på overvejelser om kampagnens...

  14. 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.)

  15. 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

  16. Ionization chamber smoke detectors

    International Nuclear Information System (INIS)

    1988-03-01

    One kind of smoke detector, the ionization-type, is regulated by the Atomic Energy Control Board (AECB) because it uses a radioactive substance in its mechanism. Radioactivity and radiation are natural phenomena, but they are not very familiar to the average householder. This has led to a number of questions being asked of the AECB. These questions and AECB responses are outlined

  17. Particle identification in a wide dynamic range based on pulse-shape analysis with solid-state detectors

    International Nuclear Information System (INIS)

    Pausch, G.; Hilscher, D.; Ortlepp, H.G.

    1994-04-01

    Heavy ions detected in a planar silicon detector were identified by exploiting a recently proposed combination of the pulse-shape and the time-of-flight techniques. We were able to resolve charge numbers up to Z = 16 within a wide dynamic range of ∼ 1:5, and to identify even isotopes for the elements up to Magnesium. The simple scheme of signal processing is based on conventional electronics and cheap enough to be exploited in large multidetector arrays. (orig.)

  18. Seismic intrusion detector system

    Science.gov (United States)

    Hawk, Hervey L.; Hawley, James G.; Portlock, John M.; Scheibner, James E.

    1976-01-01

    A system for monitoring man-associated seismic movements within a control area including a geophone for generating an electrical signal in response to seismic movement, a bandpass amplifier and threshold detector for eliminating unwanted signals, pulse counting system for counting and storing the number of seismic movements within the area, and a monitoring system operable on command having a variable frequency oscillator generating an audio frequency signal proportional to the number of said seismic movements.

  19. Position-Sensitive Organic Scintillation Detectors for Nuclear Material Accountancy

    International Nuclear Information System (INIS)

    Hausladen, P.; Newby, J.; Blackston, M.

    2015-01-01

    Recent years have seen renewed interest in fast organic scintillators with pulse shape properties that enable neutron-gamma discrimination, in part because of the present shortage of He3, but primarily because of the diagnostic value of timing and pulse height information available from such scintillators. Effort at Oak Ridge National Laboratory (ORNL) associated with fast organic scintillators has concentrated on development of position-sensitive fast-neutron detectors for imaging applications. Two aspects of this effort are of interest. First, the development has revisited the fundamental limitations on pulseshape measurement imposed by photon counting statistics, properties of the scintillator, and properties of photomultiplier amplification. This idealized limit can then be used to evaluate the performance of the detector combined with data acquisition and analysis such as free-running digitizers with embedded algorithms. Second, the development of position sensitive detectors has enabled a new generation of fast-neutron imaging instruments and techniques with sufficient resolution to give new capabilities relevant to safeguards. Toward this end, ORNL has built and demonstrated a number of passive and active fast-neutron imagers, including a proof-of-concept passive imager capable of resolving individual fuel pins in an assembly via their neutron emanations. This presentation will describe the performance and construction of position-sensing fast-neutron detectors and present results of imaging measurements. (author)

  20. First full dynamic range calibration of the JUNGFRAU photon detector

    Science.gov (United States)

    Redford, S.; Andrä, M.; Barten, R.; Bergamaschi, A.; Brückner, M.; Dinapoli, R.; Fröjdh, E.; Greiffenberg, D.; Lopez-Cuenca, C.; Mezza, D.; Mozzanica, A.; Ramilli, M.; Ruat, M.; Ruder, C.; Schmitt, B.; Shi, X.; Thattil, D.; Tinti, G.; Vetter, S.; Zhang, J.

    2018-01-01

    The JUNGFRAU detector is a charge integrating hybrid silicon pixel detector developed at the Paul Scherrer Institut for photon science applications, in particular for the upcoming free electron laser SwissFEL. With a high dynamic range, analogue readout, low noise and three automatically switching gains, JUNGFRAU promises excellent performance not only at XFELs but also at synchrotrons in areas such as protein crystallography, ptychography, pump-probe and time resolved measurements. To achieve its full potential, the detector must be calibrated on a pixel-by-pixel basis. This contribution presents the current status of the JUNGFRAU calibration project, in which a variety of input charge sources are used to parametrise the energy response of the detector across four orders of magnitude of dynamic range. Building on preliminary studies, the first full calibration procedure of a JUNGFRAU 0.5 Mpixel module is described. The calibration is validated using alternative sources of charge deposition, including laboratory experiments and measurements at ESRF and LCLS. The findings from these measurements are presented. Calibrated modules have already been used in proof-of-principle style protein crystallography experiments at the SLS. A first look at selected results is shown. Aspects such as the conversion of charge to number of photons, treatment of multi-size pixels and the origin of non-linear response are also discussed.

  1. 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.

  2. Electret radiation detector

    International Nuclear Information System (INIS)

    Kubu, M.

    1981-01-01

    The electret radiation detector consists of 30 to 35% of bee wax and of 65 to 70% of colophony. It is mainly the induction conductivity of charo.es between the dipoles in the electret which is used for detection. In the manufacture of the detector, the average atomic number of the electret can be altered by adding various compounds, such as ZnO, which also increases efficiency for gamma radiation. An alpha or beta emitter can also be built-in in the electret. (B.S.)

  3. 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

  4. DETECTORS USED IN PARTICLE PHYSICS RESEARCH

    Energy Technology Data Exchange (ETDEWEB)

    Melissines, A. C.

    1963-10-15

    Detectors used in particle physics are discussed, and their specific properties are compared. With the pictorial'' devices are included nuclear emulsions, cloud and bubble chambers, and spark chambers. Included in the digital'' devices are counters, e.g., the Geiger counter, scintillation counters, solid-state detectors, Cherenkov counters, and spark counters. Sensitivity, resolving power, time resolutions, saturation level, and energy detection are discussed. (R.E.U.)

  5. 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.)

  6. Security and gain improvement of a practical quantum key distribution using a gated single-photon source and probabilistic photon-number resolution

    International Nuclear Information System (INIS)

    Horikiri, Tomoyuki; Sasaki, Hideki; Wang, Haibo; Kobayashi, Takayoshi

    2005-01-01

    We propose a high security quantum key distribution (QKD) scheme utilizing one mode of spontaneous parametric downconversion gated by a photon number resolving detector. This photon number measurement is possible by using single-photon detectors operating at room temperature and optical fibers. By post selection, the multiphoton probability in this scheme can be reduced to lower than that of a scheme using an attenuated coherent light resulting in improvement of security. Furthermore, if distillation protocol (error correction and privacy amplification) is performed, the gain will be increased. Hence a QKD system with higher security and bit rate than the laser-based QKD system can be attained using present available technologies

  7. Magnesium borate radiothermoluminescent detectors

    International Nuclear Information System (INIS)

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

    1974-01-01

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

  8. Borehole Muon Detector Development

    Science.gov (United States)

    Bonneville, A.; Flygare, J.; Kouzes, R.; Lintereur, A.; Yamaoka, J. A. K.; Varner, G. S.

    2015-12-01

    Increasing atmospheric CO2 concentrations have spurred investigation into carbon sequestration methods. One of the possibilities being considered, storing super-critical CO2 in underground reservoirs, has drawn more attention and pilot projects are being supported worldwide. Monitoring of the post-injection fate of CO2 is of utmost importance. Generally, monitoring options are active methods, such as 4D seismic reflection or pressure measurements in monitoring wells. We propose here to develop a 4-D density tomography of subsurface CO2 reservoirs using cosmic-ray muon detectors deployed in a borehole. Muon detection is a relatively mature field of particle physics and there are many muon detector designs, though most are quite large and not designed for subsurface measurements. The primary technical challenge preventing deployment of this technology in the subsurface is the lack of miniaturized muon-tracking detectors capable of fitting in standard boreholes and that will resist the harsh underground conditions. A detector with these capabilities is being developed by a collaboration supported by the U.S. Department of Energy. Current simulations based on a Monte Carlo modeling code predict that the incoming muon angle can be resolved with an error of approximately two degrees, using either underground or sea level spectra. The robustness of the design comes primarily from the use of scintillating rods as opposed to drift tubes. The rods are arrayed in alternating layers to provide a coordinate scheme. Preliminary testing and measurements are currently being performed to test and enhance the performance of the scintillating rods, in both a laboratory and a shallow underground facility. The simulation predictions and data from the experiments will be presented.

  9. Time-resolved measurements of the focused ion beams on PBFA II

    International Nuclear Information System (INIS)

    Mix, L.P.; Stygar, W.A.; Leeper, R.J.; Maenchen, J.E.; Wenger, D.F.

    1992-01-01

    A time-resolved camera has been developed to image the intense ion beam focus on PBFA II. Focused ions from a sector of the ion diode are Rutherford scattered from a thin gold foil on the diode axis and pinhole imaged onto an array of up to 49 PIN detectors to obtain the spatially and temporally resolved images. The signals from these detectors are combined to provide a movie of the beam focus with a time resolution of about 3 ns and a spatial resolution of 2 mm over a 12 mm field of view. Monte Carlo simulations of the camera response are used with the measured ion energy to account for the time-of-flight dispersion of the beam and to convert the recorded signals to an intensity. From measurements on an 81 degree sector of the diode, average intensities on a 6 mm sphere of about 5 TW/cm 2 and energies approaching 80 kJ/cm 2 are calculated for standard proton diodes. Corresponding numbers for a lithium diode are less than those measured with protons. The details of the analysis and image reconstruction will be presented along with scaled images from recent ion focusing experiments

  10. Decomposition of time-resolved tomographic PIV

    NARCIS (Netherlands)

    Schmid, P.J.; Violato, D.; Scarano, F.

    2012-01-01

    An experimental study has been conducted on a transitional water jet at a Reynolds number of Re = 5,000. Flow fields have been obtained by means of time-resolved tomographic particle image velocimetry capturing all relevant spatial and temporal scales. The measured threedimensional flow fields have

  11. 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

  12. Semiconductor Detectors

    International Nuclear Information System (INIS)

    Cortina, E.

    2007-01-01

    Particle detectors based on semiconductor materials are among the few devices used for particle detection that are available to the public at large. In fact we are surrounded by them in our daily lives: they are used in photoelectric cells for opening doors, in digital photographic and video camera, and in bar code readers at supermarket cash registers. (Author)

  13. Capillary detectors

    International Nuclear Information System (INIS)

    Konijn, J.; Winter, K.; Vilain, P.; Wilquet, G.; Fabre, J.P.; Kozarenko, E.; Kreslo, I.; Goldberg, J.; Hoepfner, K.; Bay, A.; Currat, C.; Koppenburg, P.; Frekers, D.; Wolff, T.; Buontempo, S.; Ereditato, A.; Frenkel, A.; Liberti, B.; Martellotti, G.; Penso, G.; Ekimov, A.; Golovkin, S.; Govorun, V.; Medvedkov, A.; Vasil'chenko, V.

    1998-01-01

    The option for a microvertex detector using glass capillary arrays filled with liquid scintillator is presented. The status of capillary layers development and possible read-out techniques for high rate environment are reported. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  14. Intrinsic sensitivity calculation for a large number of LiF(Mg, Cu, P) detectors; Determinazione della sensibilita` intrinseca di un numero elevato di dosimetri personali di LiF (Mg, Cu, P)

    Energy Technology Data Exchange (ETDEWEB)

    Argazzi, E; Baldassarre, G; De Maio, U; Fantuzzi, E; Monteventi, F; Uleri, G [ENEA, Bologna (Italy). Dip. Ambiente

    1996-07-01

    At the ENEA (Italian National Agency for New Technologies, Energy and the Environment) Personal Dosimetry Service it was decided to substitute the X and gamma dosimetry system based on BeO detectors in use since 10 years ago, with new dosimeters based on the new thermoluminescence material LiF(Mg,Cu,P). This report describes the procedures through which intrinsic sensitivity of a couple of TL detectors, which constitutes a card dosemeter, is determined. The intrinsic sensitivity archive allows to calculate the value of dose applying a specific correction factor for the systematic sensitivity, difference among the 60000 detectors used at the Service, therefore reducing the final uncertainty. The characterization of 60000 TL detectors has been possible only relying on a specific procedure and an information system. The irradiation and reading procedure allowed to take into account all the various uncertainty sources on TL readings and to carry out only one reading for almost all detectors. It could get through this aim using a reference group of dosimeters, characterized with an accuracy of 3%, to check each uncertainty parameter. Data acquisition and intrinsic sensitivity calculation have been carried out through an interactive procedure based on a personal computer connected with the reading instrument.

  15. Ghost imaging with a single detector

    International Nuclear Information System (INIS)

    Bromberg, Yaron; Katz, Ori; Silberberg, Yaron

    2009-01-01

    We experimentally demonstrate pseudothermal ghost imaging and ghost diffraction using only a single detector. We achieve this by replacing the high-resolution detector of the reference beam with a computation of the propagating field, following a recent proposal by Shapiro [Phys. Rev. A 78, 061802(R) (2008)]. Since only a single detector is used, this provides experimental evidence that pseudothermal ghost imaging does not rely on nonlocal quantum correlations. In addition, we show the depth-resolving capability of this ghost imaging technique.

  16. WFIRST: Resolving the Milky Way Galaxy

    Science.gov (United States)

    Kalirai, Jason; Conroy, Charlie; Dressler, Alan; Geha, Marla; Levesque, Emily; Lu, Jessica; Tumlinson, Jason

    2018-01-01

    WFIRST will yield a transformative impact in measuring and characterizing resolved stellar populations in the Milky Way. The proximity and level of detail that such populations need to be studied at directly map to all three pillars of WFIRST capabilities - sensitivity from a 2.4 meter space based telescope, resolution from 0.1" pixels, and large 0.3 degree field of view from multiple detectors. In this poster, we describe the activities of the WFIRST Science Investigation Team (SIT), "Resolving the Milky Way with WFIRST". Notional programs guiding our analysis include targeting sightlines to establish the first well-resolved large scale maps of the Galactic bulge aand central region, pockets of star formation in the disk, benchmark star clusters, and halo substructure and ultra faint dwarf satellites. As an output of this study, our team is building optimized strategies and tools to maximize stellar population science with WFIRST. This will include: new grids of IR-optimized stellar evolution and synthetic spectroscopic models; pipelines and algorithms for optimal data reduction at the WFIRST sensitivity and pixel scale; wide field simulations of Milky Way environments including new astrometric studies; and strategies and automated algorithms to find substructure and dwarf galaxies in the Milky Way through the WFIRST High Latitude Survey.

  17. Ruggedization of CdZnTe detectors and detector assemblies for radiation detection applications

    Energy Technology Data Exchange (ETDEWEB)

    Lu, P.H., E-mail: pinghe.lu@redlen.com; Gomolchuk, P.; Chen, H.; Beitz, D.; Grosser, A.W.

    2015-06-01

    This paper described improvements in the ruggedization of CdZnTe detectors and detector assemblies for use in radiation detection applications. Research included experimenting with various conductive and underfill adhesive material systems suitable for CZT substrates. A detector design with encapsulation patterning was developed to protect detector surfaces and to control spacing between CZT anode and PCB carrier. Robustness of bare detectors was evaluated through temperature cycling and metallization shear testing. Attachment processes using well-chosen adhesives and PCB carrier materials were optimized to improve reliability of detector assemblies, resulted in Improved Attachment Detector Assembly. These detector assemblies were subjected to aggressive temperature cycling, and varying levels of drop/shock and vibration, in accordance with modified JEDEC, ANSI and FedEx testing standards, to assess their ruggedness. Further enhanced detector assembly ruggedization methods were investigated involving adhesive conformal coating, potting and dam filling on detector assemblies, which resulted in the Enhanced Ruggedization Detector Assembly. Large numbers of CZT detectors and detector assemblies with 5 mm and 15 mm thick, over 200 in total, were tested. Their performance was evaluated by exposure to various radioactive sources using comprehensive predefined detector specifications and testing protocols. Detector assemblies from improved attachment and enhanced ruggedization showed stable performances during the harsh environmental condition tests. In conclusion, significant progress has been made in improving the reliability and enhancing the ruggedness of CZT detector assemblies for radiation detection applications deployed in operational environments. - Highlights: • We developed ruggedization methods to enhance reliability of CZT detector assemblies. • Attachment of CZT radiation detectors was improved through comparative studies. • Bare detector metallization

  18. Ionization detector

    Energy Technology Data Exchange (ETDEWEB)

    Solomon, E E

    1976-02-27

    This invention concerns a fire detection system making use of a beta source. The ionisation detector includes a first and second chamber respectively comprising a first and second electrode, preferably a plate, with a common electrode separating the first and second chamber. Communication is provided between these chambers through a set of orifices and each chamber also has a set of orifices for communication with the ambient atmosphere. One or both chambers can comprise a particle source, preferably beta. The detector also has an adjustable electrode housed in one of the chambers to regulate the voltage between the fixed electrode of this chamber and the common electrode located between the chambers. The electrodes of the structure are connected to a detection circuit that spots a change in the ionisation current when a fire alarm condition arises. The detection circuit of a new type includes a relaxation oscillator with a programmable unijunction transistor and a light emitting diode.

  19. High purity liquid phase epitaxial gallium arsenide nuclear radiation detector

    International Nuclear Information System (INIS)

    Alexiev, D.; Butcher, K.S.A.

    1991-11-01

    Surface barrier radiation detector made from high purity liquid phase epitaxial gallium arsenide wafers have been operated as X- and γ-ray detectors at various operating temperatures. Low energy isotopes are resolved including 241 Am at 40 deg C. and the higher gamma energies of 235 U at -80 deg C. 15 refs., 1 tab., 6 figs

  20. MUST detector

    International Nuclear Information System (INIS)

    Blumenfeld, Y.; Auger, F.; Sauvestre, J.E.

    1999-01-01

    The IPN-Orsay, in collaboration with the SPhN-Saclay and the DPTA Bruyeres, has built an array of 8 telescopes based on Si-strip technology for the study of direct reactions induced by radioactive beams. The detectors are described, along with the compact high density VXI electronics and the stand-alone data acquisition system developed in the laboratory. One telescope was tested using an 40 Ar beam and the measured performances are discussed. (authors)

  1. Radiation detector

    Energy Technology Data Exchange (ETDEWEB)

    Ohata, Shuichi; Takeuchi, Yoji

    1968-10-30

    Herein disclosed is an ionization chamber the airtightness of which can be readily tested. The ionization chamber is characterized in that a small amount of helium gas is filled in the chamber in combination with other ionization gases such as argon gas, xenon gas and the like. Helium leakage from the chamber is measured by a known helium gas sensor in a vacuum vessel. Hence the long term drift of the radiation detector sensitivity may be determined.

  2. Highly resolving computerized tomography

    International Nuclear Information System (INIS)

    Kurtz, B.; Petersen, D.; Walter, E.

    1984-01-01

    With the development of highly-resolving devices for computerized tomography, CT diagnosis of the lumbar vertebral column has gained increasing importance. As an ambulatory, non-invasive method it has proved in comparative studies to be at least equivalent to myelography in the detection of dislocations of inter-vertebral disks (4,6,7,15). Because with modern devices not alone the bones, but especially the spinal soft part structures are clearly and precisely presented with a resolution of distinctly below 1 mm, a further improvement of the results is expected as experience will increase. The authors report on the diagnosis of the lumbar vertebral column with the aid of a modern device for computerized tomography and wish to draw particular attention to the possibility of doing this investigation as a routine, and to the diagnostic value of secondary reconstructions. (BWU) [de

  3. Highly resolving computerized tomography

    Energy Technology Data Exchange (ETDEWEB)

    Kurtz, B.; Petersen, D.; Walter, E.

    1984-01-01

    With the development of highly-resolving devices for computerized tomography, CT diagnosis of the lumbar vertebral column has gained increasing importance. As an ambulatory, non-invasive method it has proved in comparative studies to be at least equivalent to myelography in the detection of dislocations of inter-vertebral disks (4,6,7,15). Because with modern devices not alone the bones, but especially the spinal soft part structures are clearly and precisely presented with a resolution of distinctly below 1 mm, a further improvement of the results is expected as experience will increase. The authors report on the diagnosis of the lumbar vertebral column with the aid of a modern device for computerized tomography and wish to draw particular attention to the possibility of doing this investigation as a routine, and to the diagnostic value of secondary reconstructions.

  4. Report of the specialized detector group

    International Nuclear Information System (INIS)

    Witherell, M.S.

    1984-01-01

    The Specialized Detector Group was assigned the task of studying the types of detectors, other than general purpose detectors, that might be suitable for the SSC. At the start of the Snowmass workshop, a number of physics topics were identified which could call for a specialized detector. The modest size of the specialized detector group dictated that we concentrate on a few of these detectors, and not try to consider all candidates. Subgroups were formed for each type of detector, and they worked completely independently on their very different problems. The members of a subgroup were also members of the corresponding group within the Physics area. Because of the wide variety of problems faced by the various subgroups, the detectors will be described in separate papers within these proceedings (some of them within the Physics group reports). Thus, this report gives a summary of these designs and discusses some general considerations

  5. Performance characterization of compressed sensing positron emission tomography detectors and data acquisition system

    Science.gov (United States)

    Chang, Chen-Ming; Grant, Alexander M.; Lee, Brian J.; Kim, Ealgoo; Hong, KeyJo; Levin, Craig S.

    2015-08-01

    In the field of information theory, compressed sensing (CS) had been developed to recover signals at a lower sampling rate than suggested by the Nyquist-Shannon theorem, provided the signals have a sparse representation with respect to some base. CS has recently emerged as a method to multiplex PET detector readouts thanks to the sparse nature of 511 keV photon interactions in a typical PET study. We have shown in our previous numerical studies that, at the same multiplexing ratio, CS achieves higher signal-to-noise ratio (SNR) compared to Anger and cross-strip multiplexing. In addition, unlike Anger logic, multiplexing by CS preserves the capability to resolve multi-hit events, in which multiple pixels are triggered within the resolving time of the detector. In this work, we characterized the time, energy and intrinsic spatial resolution of two CS detectors and a data acquisition system we have developed for a PET insert system for simultaneous PET/MRI. The CS detector comprises a 2× 4 mosaic of 4× 4 arrays of 3.2× 3.2× 20 mm3 lutetium-yttrium orthosilicate crystals coupled one-to-one to eight 4× 4 silicon photomultiplier arrays. The total number of 128 pixels is multiplexed down to 16 readout channels by CS. The energy, coincidence time and intrinsic spatial resolution achieved by two CS detectors were 15.4+/- 0.1 % FWHM at 511 keV, 4.5 ns FWHM and 2.3 mm FWHM, respectively. A series of experiments were conducted to measure the sources of time jitter that limit the time resolution of the current system, which provides guidance for potential system design improvements. These findings demonstrate the feasibility of compressed sensing as a promising multiplexing method for PET detectors.

  6. Encapsulated thermopile detector array for IR microspectrometer

    NARCIS (Netherlands)

    Wu, H.; Emadi, A.; De Graaf, G.; Wolffenbuttel, R.F.

    2010-01-01

    The miniaturized IR spectrometer discussed in this paper is comprised of: slit, planar imaging diffraction grating and Thermo-Electric (TE) detector array, which is fabricated using CMOS compatible MEMS technology. The resolving power is maximized by spacing the TE elements at an as narrow as

  7. Amplitude distributions of dark counts and photon counts in NbN superconducting single-photon detectors integrated with the HEMT readout

    Energy Technology Data Exchange (ETDEWEB)

    Kitaygorsky, J. [Kavli Institute of Nanoscience Delft, Delft University of Technology, 2600 GA Delft (Netherlands); Department of Electrical and Computer Engineering and Laboratory for Laser Energetics, University of Rochester, Rochester, NY 14627-0231 (United States); Słysz, W., E-mail: wslysz@ite.waw.pl [Institute of Electron Technology, PL-02 668 Warsaw (Poland); Shouten, R.; Dorenbos, S.; Reiger, E.; Zwiller, V. [Kavli Institute of Nanoscience Delft, Delft University of Technology, 2600 GA Delft (Netherlands); Sobolewski, Roman [Department of Electrical and Computer Engineering and Laboratory for Laser Energetics, University of Rochester, Rochester, NY 14627-0231 (United States)

    2017-01-15

    Highlights: • A new operation regime of NbN superconducting single-photon detectors (SSPDs). • A better understanding of the origin of dark counts generated by the detector. • A promise of PNR functionality in SSPD measurements. - Abstract: We present a new operation regime of NbN superconducting single-photon detectors (SSPDs) by integrating them with a low-noise cryogenic high-electron-mobility transistor and a high-load resistor. The integrated sensors are designed to get a better understanding of the origin of dark counts triggered by the detector, as our scheme allows us to distinguish the origin of dark pulses from the actual photon pulses in SSPDs. The presented approach is based on a statistical analysis of amplitude distributions of recorded trains of the SSPD photoresponse transients. It also enables to obtain information on energy of the incident photons, as well as demonstrates some photon-number-resolving capability of meander-type SSPDs.

  8. Requirements on high resolution detectors

    Energy Technology Data Exchange (ETDEWEB)

    Koch, A. [European Synchrotron Radiation Facility, Grenoble (France)

    1997-02-01

    For a number of microtomography applications X-ray detectors with a spatial resolution of 1 {mu}m are required. This high spatial resolution will influence and degrade other parameters of secondary importance like detective quantum efficiency (DQE), dynamic range, linearity and frame rate. This note summarizes the most important arguments, for and against those detector systems which could be considered. This article discusses the mutual dependencies between the various figures which characterize a detector, and tries to give some ideas on how to proceed in order to improve present technology.

  9. MUON DETECTORS: RPC

    CERN Multimedia

    P. Paolucci

    2012-01-01

    The RPC system is operating with a very high uptime, an average chamber efficiency of about 95% and an average cluster size around 1.8. The average number of active channels is 97.7%. Eight chambers are disconnected and forty are working in single-gap mode due to high-voltage problems. The total luminosity lost due to RPCs in 2012 is 88.46 pb–1. One of the main goals of 2012 was to improve the stability of the endcap trigger that is strongly correlated to the performances of the detector, due to the 3-out-3 trigger logic. At beginning of 2011 the instability of the detector efficiency was about 10%. Detailed studies found that this was mainly due to the strong correlation between the performance of the detector and the atmospheric pressure (P). Figure XXY shows the linear correlation between the average cluster size of the endcap chamber versus P. This effect is expected for gaseous detectors and can be reduced by correcting the applied high-voltage working point (HVapp) according to the followi...

  10. Smoke detectors

    International Nuclear Information System (INIS)

    Fung, C.K.

    1981-01-01

    This describes a smoke detector comprising a self-luminous light source and a photosensitive device which is so arranged that the light source is changed by the presence of smoke in a detecting region. A gaseous tritium light source is used. This consists of a borosilicate glass bulb with an internal phosphor coating, filled with tritium gas. The tritium emits low energy beta particles which cause the phosphor to glow. This is a reliable light source which needs no external power source. The photosensitive device may be a phototransistor and may drive a warning device through a directly coupled transistor amplifier. (U.K.)

  11. Resolving inventory differences

    International Nuclear Information System (INIS)

    Weber, J.H.; Clark, J.P.

    1991-01-01

    Determining the cause of an inventory difference (ID) that exceeds warning or alarm limits should not only involve investigation into measurement methods and reexamination of the model assumptions used in the calculation of the limits, but also result in corrective actions that improve the quality of the accountability measurements. An example illustrating methods used by Savannah River Site (SRS) personnel to resolve an ID is presented that may be useful to other facilities faced with a similar problem. After first determining that no theft or diversion of material occurred and correcting any accountability calculation errors, investigation into the IDs focused on volume and analytical measurements, limit of error of inventory difference (LEID) modeling assumptions, and changes in the measurement procedures and methods prior to the alarm. There had been a gradual gain trend in IDs prior to the alarm which was reversed by the alarm inventory. The majority of the NM in the facility was stored in four large tanks which helped identify causes for the alarm. The investigation, while indicating no diversion or theft, resulted in changes in the analytical method and in improvements in the measurement and accountability that produced a 67% improvement in the LEID

  12. Compound Semiconductor Radiation Detectors

    CERN Document Server

    Owens, Alan

    2012-01-01

    Although elemental semiconductors such as silicon and germanium are standard for energy dispersive spectroscopy in the laboratory, their use for an increasing range of applications is becoming marginalized by their physical limitations, namely the need for ancillary cooling, their modest stopping powers, and radiation intolerance. Compound semiconductors, on the other hand, encompass such a wide range of physical and electronic properties that they have become viable competitors in a number of applications. Compound Semiconductor Radiation Detectors is a consolidated source of information on all aspects of the use of compound semiconductors for radiation detection and measurement. Serious Competitors to Germanium and Silicon Radiation Detectors Wide-gap compound semiconductors offer the ability to operate in a range of hostile thermal and radiation environments while still maintaining sub-keV spectral resolution at X-ray wavelengths. Narrow-gap materials offer the potential of exceeding the spectral resolutio...

  13. Time-resolved studies

    International Nuclear Information System (INIS)

    Mills, D.M.

    1992-01-01

    When new or more powerful probes become available that offer both shorter data-collection times and the opportunity to apply innovative approaches to established techniques, it is natural that investigators consider the feasibility of exploring the kinetics of time-evolving systems. This stimulating area of research not only can lead to insights into the metastable or excited states that a system may populate on its way to a ground state, but can also lead to a better understanding of that final state. Synchrotron radiation, with its unique properties, offers just such a tool to extend X-ray measurements from the static to the time-resolved regime. The most straight-forward application of synchrotron radiation to the study of transient phenomena is directly through the possibility of decreased data-collection times via the enormous increase in flux over that of a laboratory X-ray system. Even further increases in intensity can be obtained through the use of novel X-ray optical devices. Widebandpass monochromators, e.g., that utilize the continuous spectral distribution of synchrotron radiation, can increase flux on the sample several orders of magnitude over conventional X-ray optical systems thereby allowing a further shortening of the data-collection time. Another approach that uses the continuous spectral nature of synchrotron radiation to decrease data-collection times is the open-quote parallel data collectionclose quotes method. Using this technique, intensities as a function of X-ray energy are recorded simultaneously for all energies rather than sequentially recording data at each energy, allowing for a dramatic decrease in the data-collection time

  14. AgesGalore-A software program for evaluating spatially resolved luminescence data

    International Nuclear Information System (INIS)

    Greilich, S.; Harney, H.-L.; Woda, C.; Wagner, G.A.

    2006-01-01

    Low-light luminescence is usually recorded by photomultiplier tubes (PMTs) yielding integrated photon-number data. Highly sensitive CCD (charged coupled device) detectors allow for the spatially resolved recording of luminescence. The resulting two-dimensional images require suitable software for data processing. We present a recently developed software program specially designed for equivalent-dose evaluation in the framework of optically stimulated luminescence (OSL) dating. The software is capable of appropriate CCD data handling, parameter estimation using a Bayesian approach, and the pixel-wise fitting of functions for time and dose dependencies to the luminescence signal. The results of the fitting procedure and the equivalent-dose evaluation can be presented and analyzed both as spatial and as frequency distributions

  15. Development of high efficiency neutron detectors

    International Nuclear Information System (INIS)

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

    1993-01-01

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

  16. Avalanche photodiodes for ISABELLE detectors

    International Nuclear Information System (INIS)

    Strand, R.C.

    1979-01-01

    At ISABELLE some requirements for detecting bursts of photons are not met by standard photomultiplier tubes. The characteristics of immunity to magnetic fields, small size (few mm), low power consumption (approx. 100 mW), insensitivity to optical overloads, and wide dynamic range (approx. 60 dB) are achieved with difficulty, if at all, with PMTs. These are characteristics of the solid state avalanche photodiode (APD), the preferred detector for light-wave communications. Successful field tests with APD detectors stimulated the design of standard optical-fiber communication systems to replace wire carriers by the early 1980's. In other characteristics, i.e., counting rate, pulse-height resolution, effective quantum efficiency, detection efficiency, and reliability, bare APDs are equivalent to standard PMTs. APDs with currently available amplifiers cannot resolve single photoelectrons but they could provide reasonable detection efficiencies and pulse-height resolution for packets of approx. > 100 photons. Commercially available APDs can cost up to 100 times as much as PMTs per active area, but they are potentially much cheaper. Six topics are discussed: (1) detectors for light-wave communication and detectors for particles, (2) avalanche photodiodes, (3) commercially available APDs, (4) dynamic response of PMTs and bare APDs, (5) photon counting with cold APDs, and (6) conclusions and recommendations

  17. Radiation detector

    International Nuclear Information System (INIS)

    Conrad, B.; Finkenzeller, J.; Kiiehn, G.; Lichtenberg, W.

    1984-01-01

    In an exemplary embodiment, a flat radiation beam is detected having a common electrode disposed parallel to the beam plane at one side and a common support with a series of individual conductors providing electrodes opposite successive portions of the common electrode and lying in a plane also parallel to the beam plane. The beam may be fan-shaped and the individual electrodes may be aligned with respective ray paths separated by uniform angular increments in the beam plane. The individual conductors and the connection thereof to the exterior of the detector housing may be formed on an insulator which can be folded into a T-shape for leading the supply conductors for alternate individual conductors toward terminals at opposite sides of the chamber

  18. Particle detectors

    CERN Document Server

    Hilke, Hans Jürgen; Joram, Christian; CERN. Geneva

    1991-01-01

    Lecture 5: Detector characteristics: ALEPH Experiment cut through the devices and events - Discuss the principles of the main techniques applied to particle detection ( including front-end electronics), the construction and performance of some of the devices presently in operartion and a few ideas on the future performance. Lecture 4-pt. b Following the Scintillators. Lecture 4-pt. a : Scintillators - Used for: -Timing (TOF, Trigger) - Energy Measurement (Calorimeters) - Tracking (Fibres) Basic scintillation processes- Inorganic Scintillators - Organic Scintil - Discuss the principles of the main techniques applied to particle detection ( including front-end electronics), the construction and performance of some of the devices presently in operation and a fiew ideas on future developpement session 3 - part. b Following Calorimeters lecture 3-pt. a Calorimeters - determine energy E by total absorption of charged or neutral particles - fraction of E is transformed into measurable quantities - try to acheive sig...

  19. Smoke detectors

    International Nuclear Information System (INIS)

    Bryant, J.

    1979-01-01

    An ionization smoke detector consisting of two electrodes defining an ionization chamber permitting entry of smoke, a radioactive source to ionize gas in the chamber and a potential difference applied across the first and second electrodes to cause an ion current to flow is described. The current is affected by entry of smoke. An auxiliary electrode is positioned in the ionization chamber between the first and second electrodes, and it is arranged to maintain or create a potential difference between the first electrode and the auxiliary electrode. The auxiliary electrode may be used for testing or for adjustment of sensitivity. A collector electrode divides the chamber into two regions with the auxiliary electrode in the outer sensing region. (U.K.)

  20. Ionization detector

    International Nuclear Information System (INIS)

    Solomon, E.E.

    1980-01-01

    A safe and reliable apparatus for detecting products of combustion and aerosols in the atmosphere was developed which uses a beta source. It is easy to adjust for optimum performance. The ionization detector comprises a double chamber; one of the chambers is the basic sensing chamber. The sensing chamber is ported to both the secondary chambers to account for slow ambient changes in the atmosphere outside of the chamber. The voltages from the ionization chamber are adjusted with electrodes in each chamber. The ionization chamber contains baffles to direct the air to be sensed as well as an electrostatic screen. A unique electronic circuit provides an inexpensive and reliable means for detecting the signal change which occurs in the ionization chamber. The decision level of the alarm circuit can be adjusted to allow for any desired sensitivity. (D.N.)

  1. In-core monitoring detectors

    International Nuclear Information System (INIS)

    Mitelman, M.G.

    2001-01-01

    The main task of in-core monitoring consists in securing observability of the reactor installation in all possible operation modes (normal, transient, accident and post-accident). Operation safety at acceptable cost can be achieved by optimized measurement errors. The range of sensors applied as in-core detectors for operative measurements in the industry is very limited in number. Among them might be cited self powered neutron detectors (SPND) and thermocouples. Sensors are incorporated in the in-core detectors assemblies (SVRD). The presentation makes an effort to touch upon the problems of assuring and increasing quality of in-core on-line measurements. So we do not consider systems using movable detectors, as the latter do not assure on-line measurements. (Authors)

  2. Development of a detector control system for the serially powered ATLAS pixel detector at the HL-LHC

    Energy Technology Data Exchange (ETDEWEB)

    Puellen, Lukas

    2015-02-10

    protocol, the I2C-HC protocol is used. A first prototype for the DCS chip was designed and tested in terms of this thesis. This prototype, the PSPP (Pixel Serial Powering and Protection) chip, was fabricated in a commercial 130 nm process as a proof-of-principle test. It contains all necessary functionality to supervise an entire serially powered stave. This includes, among others, a shunt regulator to generate the chips supply voltage, shunt transistors to switch off the serially powered modules, a comparator monitoring the supply voltage of each detector module, an I2C-HC-slave logic core, and the physical layers to create an I2C-HC bus with floating nodes. Thereby, the number of lines to supply and control the PSPP chips could be reduced to three per powering group, which keeps the material budget in the detector volume at a minimum. The PSPP chip was tested and showed three minor and one major faults. Thereby all the minor faults could be resolved in the test setup by workarounds. The major fault affects the implemented ADC and still needs to be understood completely. Hence, reliable ADC conversions are not possible with the PSPP. Fortunately the remaining functions of the PSPP were tested successfully and it was possible to operate and supervise a serial power chain in the lab, similar to a power group in the detector. Furthermore, the tests with a serial chain of PSPP chips have shown, that the right choice of the power supply for a serially powered chain of detector modules is critical. During the tests it was not possible to find a power supply, which could satisfy the demands of a stable current source. Hence further investigation in this matter is necessary. Besides the design and testing of the first prototype for the DCS chip, the need for hardness-by-design techniques was calculated, which are necessary to ensure that the high amount of radiation in the pixel detector volume does not interfere with the detector operation. In the near future, long term tests

  3. Development of a detector control system for the serially powered ATLAS pixel detector at the HL-LHC

    International Nuclear Information System (INIS)

    Puellen, Lukas

    2015-01-01

    protocol, the I2C-HC protocol is used. A first prototype for the DCS chip was designed and tested in terms of this thesis. This prototype, the PSPP (Pixel Serial Powering and Protection) chip, was fabricated in a commercial 130 nm process as a proof-of-principle test. It contains all necessary functionality to supervise an entire serially powered stave. This includes, among others, a shunt regulator to generate the chips supply voltage, shunt transistors to switch off the serially powered modules, a comparator monitoring the supply voltage of each detector module, an I2C-HC-slave logic core, and the physical layers to create an I2C-HC bus with floating nodes. Thereby, the number of lines to supply and control the PSPP chips could be reduced to three per powering group, which keeps the material budget in the detector volume at a minimum. The PSPP chip was tested and showed three minor and one major faults. Thereby all the minor faults could be resolved in the test setup by workarounds. The major fault affects the implemented ADC and still needs to be understood completely. Hence, reliable ADC conversions are not possible with the PSPP. Fortunately the remaining functions of the PSPP were tested successfully and it was possible to operate and supervise a serial power chain in the lab, similar to a power group in the detector. Furthermore, the tests with a serial chain of PSPP chips have shown, that the right choice of the power supply for a serially powered chain of detector modules is critical. During the tests it was not possible to find a power supply, which could satisfy the demands of a stable current source. Hence further investigation in this matter is necessary. Besides the design and testing of the first prototype for the DCS chip, the need for hardness-by-design techniques was calculated, which are necessary to ensure that the high amount of radiation in the pixel detector volume does not interfere with the detector operation. In the near future, long term tests

  4. Computed tomography with energy-resolved detection: a feasibility study

    Science.gov (United States)

    Shikhaliev, Polad M.

    2008-03-01

    The feasibility of computed tomography (CT) with energy-resolved x-ray detection has been investigated. A breast CT design with multi slit multi slice (MSMS) data acquisition was used for this study. The MSMS CT includes linear arrays of photon counting detectors separated by gaps. This CT configuration allows for efficient scatter rejection and 3D data acquisition. The energy-resolved CT images were simulated using a digital breast phantom and the design parameters of the proposed MSMS CT. The phantom had 14 cm diameter and 50/50 adipose/glandular composition, and included carcinoma, adipose, blood, iodine and CaCO3 as contrast elements. The x-ray technique was 90 kVp tube voltage with 660 mR skin exposure. Photon counting, charge (energy) integrating and photon energy weighting CT images were generated. The contrast-to-noise (CNR) improvement with photon energy weighting was quantified. The dual energy subtracted images of CaCO3 and iodine were generated using a single CT scan at a fixed x-ray tube voltage. The x-ray spectrum was electronically split into low- and high-energy parts by a photon counting detector. The CNR of the energy weighting CT images of carcinoma, blood, adipose, iodine, and CaCO3 was higher by a factor of 1.16, 1.20, 1.21, 1.36 and 1.35, respectively, as compared to CT with a conventional charge (energy) integrating detector. Photon energy weighting was applied to CT projections prior to dual energy subtraction and reconstruction. Photon energy weighting improved the CNR in dual energy subtracted CT images of CaCO3 and iodine by a factor of 1.35 and 1.33, respectively. The combination of CNR improvements due to scatter rejection and energy weighting was in the range of 1.71-2 depending on the type of the contrast element. The tilted angle CZT detector was considered as the detector of choice. Experiments were performed to test the effect of the tilting angle on the energy spectrum. Using the CZT detector with 20° tilting angle decreased the

  5. Camera System MTF: combining optic with detector

    Science.gov (United States)

    Andersen, Torben B.; Granger, Zachary A.

    2017-08-01

    MTF is one of the most common metrics used to quantify the resolving power of an optical component. Extensive literature is dedicated to describing methods to calculate the Modulation Transfer Function (MTF) for stand-alone optical components such as a camera lens or telescope, and some literature addresses approaches to determine an MTF for combination of an optic with a detector. The formulations pertaining to a combined electro-optical system MTF are mostly based on theory, and assumptions that detector MTF is described only by the pixel pitch which does not account for wavelength dependencies. When working with real hardware, detectors are often characterized by testing MTF at discrete wavelengths. This paper presents a method to simplify the calculation of a polychromatic system MTF when it is permissible to consider the detector MTF to be independent of wavelength.

  6. Silicon radiation detectors

    International Nuclear Information System (INIS)

    Lutz, G.

    1995-01-01

    An introduction to and an overview of function principles and properties of semiconductor radiation detectors is attempted. The paper is addressed to people interested in detector development but not already experts in the field of semiconductor detectors. (orig.)

  7. Sandwich veto detector at COMPASS experiment

    International Nuclear Information System (INIS)

    Sarkar, S.; Dasgupta, S.S.; Calcutta-COMPASS group

    2010-01-01

    This paper presents the newly build Sandwich Detector for 190 GeV hadron run of COMPASS Experiment at CERN. The technical details and the testing procedures are included to highlight the physics objective of the installation. Single electron detection techniques has been developed and used to scale the performance of the detector. This analysis can predict the number of single electrons per MIP at the scintillation detector. (author)

  8. Detector array and method

    International Nuclear Information System (INIS)

    Timothy, J.G.; Bybee, R.L.

    1978-01-01

    A detector array and method are described in which sets of electrode elements are provided. Each set consists of a number of linear extending parallel electrodes. The sets of electrode elements are disposed at an angle (preferably orthogonal) with respect to one another so that the individual elements intersect and overlap individual elements of the other sets. Electrical insulation is provided between the overlapping elements. The detector array is exposed to a source of charged particles which in accordance with one embodiment comprise electrons derived from a microchannel array plate exposed to photons. Amplifier and discriminator means are provided for each individual electrode element. Detection means are provided to sense pulses on individual electrode elements in the sets, with coincidence of pulses on individual intersecting electrode elements being indicative of charged particle impact at the intersection of the elements. Electronic readout means provide an indication of coincident events and the location where the charged particle or particles impacted. Display means are provided for generating appropriate displays representative of the intensity and locaton of charged particles impacting on the detector array

  9. MUON DETECTORS: RPC

    CERN Multimedia

    P. Paolucci

    2011-01-01

    RPC detector calibration, HV scan Thanks to the high LHC luminosity and to the corresponding high number of muons created in the first part of the 2011 the RPC community had, for the first time, the possibility to calibrate every single detector element (roll).The RPC steering committee provided the guidelines for both data-taking and data analysis and a dedicated task force worked from March to April on this specific issue. The main goal of the RPC calibration was to study the detector efficiency as a function of high-voltage working points, fit the obtained “plateau curve” with a sigmoid function and determine the “best” high-voltage working point of every single roll. On 18th and 19th March, we had eight runs at different voltages. On 27th March, the full analysis was completed, showing that 60% of the rolls had already a very good fit with an average efficiency greater than 93% in the plateau region. To improve the fit we decided to take three more runs (15th April...

  10. MUON DETECTORS: DT

    CERN Document Server

    M. Dallavalle.

    The DT system is ready for the LHC start up. The status of detector hardware, control and safety, of the software for calibration and monitoring and of people has been reviewed at several meetings, starting with the CMS Action Matrix Review and with the Muon Barrel Workshop (October 5 to 7). The disconnected HV channels are at a level of about 0.1%. The loss in detector acceptance because of failures in the Read-Out and Trigger electronics is about 0.5%. The electronics failure rate has been lower this year: next year will tell us whether the rate has stabilised and hopefully will confirm that the number of spares is adequate for ten years operation. Although the detector safety control is very accurate and robust, incidents have happened. In particular the DT system suffered from a significant water leak, originated in the top part of YE+1, that generated HV trips in eighteen chambers going transversely down from the top sector in YB+2 to the bottom sector in YB-2. All chambers recovered and all t...

  11. Calibration of detector efficiency of neutron detector

    International Nuclear Information System (INIS)

    Guo Hongsheng; He Xijun; Xu Rongkun; Peng Taiping

    2001-01-01

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

  12. International Scoping Study (ISS) for a future neutrino factory and Super-Beam facility. Detectors and flux instrumentation for future neutrino facilities

    International Nuclear Information System (INIS)

    Abe, T; Aihara, H; Andreopoulos, C; Ankowski, A; Badertscher, A; Battistoni, G; Blondel, A; Bouchez, J; Bross, A; Ellis, M; Bueno, A; Camilleri, L; Campagne, J E; Cazes, A; Cervera-Villanueva, A; De Lellis, G; Di Capua, F; Ereditato, A; Esposito, L S

    2009-01-01

    This report summarises the conclusions from the detector group of the International Scoping Study of a future Neutrino Factory and Super-Beam neutrino facility. The baseline detector options for each possible neutrino beam are defined as follows: 1. A very massive (Megaton) water Cherenkov detector is the baseline option for a sub-GeV Beta Beam and Super Beam facility. 2. There are a number of possibilities for either a Beta Beam or Super Beam (SB) medium energy facility between 1-5 GeV. These include a totally active scintillating detector (TASD), a liquid argon TPC or a water Cherenkov detector. 3. A 100 kton magnetized iron neutrino detector (MIND) is the baseline to detect the wrong sign muon final states (golden channel) at a high energy (20-50 GeV) neutrino factory from muon decay. A 10 kton hybrid neutrino magnetic emulsion cloud chamber detector for wrong sign tau detection (silver channel) is a possible complement to MIND, if one needs to resolve degeneracies that appear in the δ-θ 13 parameter space.

  13. Position detector

    International Nuclear Information System (INIS)

    Hayakawa, Toshifumi.

    1985-01-01

    Purpose: To enable to detect the position of an moving object in a control rod position detector, stably in a digital manner at a high accuracy and free from the undesired effects of circumstantial conditions such as the reactor temperature. Constitution: Coils connected in parallel with each other are disposed along the passage of a moving object and variable resistors and relays are connected in series with each of the coils respectively. Light emitting diodes is connected in series with the contacts of the respective relays. The resistance value of the variable resistors are adjusted depending on the changes in the circumstantial conditions and temperature distribution upon carrying out the positional detection. When the object is inserted into a coils, the relevant relay is deenergized, by which the relay contacts are closed to light up the diode. In the same manner, as the object is successively inserted into the coils, the diodes are lighted-up successively thereby enabling highly accurate and stable positional detection in a digital manner, free from the undesired effects of the circumstantial conditions. (Horiuchi, T.)

  14. MUON DETECTOR

    CERN Multimedia

    F. Gasparini

    DT As announced in the previous Bulletin MU DT completed the installation of the vertical chambers of barrel wheels 0, +1 and +2. 242 DT and RPC stations are now installed in the negative barrel wheels. The missing 8 (4 in YB-1 and 4 in YB-2) chambers can be installed only after the lowering of the two wheels into the UX cavern, which is planned for the last quarter of the year. Cabling on the surface of the negative wheels was finished in May after some difficulties with RPC cables. The next step was to begin the final commissioning of the wheels with the final trigger and readout electronics. Priority was giv¬en to YB0 in order to check everything before the chambers were covered by cables and services of the inner detectors. Commissioning is not easy since it requires both activity on the central and positive wheels underground, as well as on the negative wheels still on the surface. The DT community is requested to commission the negative wheels on surface to cope with a possible lack of time a...

  15. DETECTORS: Vienna - beyond the wire

    International Nuclear Information System (INIS)

    Krammer, Manfred; Regler, Meinhard

    1995-01-01

    presentations. Both ATLAS and CMS demonstrated different approaches to mastering the difficulties of covering large areas with precise detectors capable of resolving consecutive bunches. Proposed techniques included thin gap chambers, straw drift tubes, pressurized drift tubes, resistive plate chambers...

  16. Velocity determination of neutron-rich projectile fragments with a ring-imaging Cherenkov detector

    International Nuclear Information System (INIS)

    Zeitelhack, K.

    1992-11-01

    For the velocity determination of relativistic heavy ions (A>100) in the energy range 300A.MeV ≤ E kin ≤ 2A.GeV a highly resolving, compact ring-imaging Cherenkov counter with large dynamical measurement range was developed. The Cherenkov light cone emitted in the flight of a relativistic heavy ion by a liquid layer (C 6 F 14 ) is focused on the entrance window of a one-dimensional position-resolving VUV-sensitive photon detector. This gas detector is operated at atmospheric pressure with a mixture of 90% methane and 10% isobutane with 0.04% TMAE as photosensitive admixture. For 725A.MeV 129 Xe ions a velocity resolution Δβ/β=1.8.10 -3 and a nuclear charge-number resolution ΔZ/Z=5.1.10 -2 was reached. The over the photon energy range 5.4 eV ≤ E γ ≤ 7.2 eV averaged detection efficiency of the detector system was determined to ε tot =2.8%>. At the 0deg magnet spectrometer Fragmentseparator of the GSI Darmstadt the RICH detector was for the first time applied for the identification of nuclear charge number and mass of heavy relativistic projectile fragments. In the experiment the production cross sections of very neutron-rich nuclei by fragmentation of 136 Xe projectiles in the reaction 76A.MeV 136 Xe on 27 Al were determined. From the measured production erates for the production of the double-magic nucleus 132 Zn in this reaction a cross section of σ=(0.4± 0.3 0.6 ) μbarn can be extrapolated. (orig./HSI) [de

  17. Detector simulation needs for detector designers

    International Nuclear Information System (INIS)

    Hanson, G.G.

    1987-11-01

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

  18. The ALICE Silicon Pixel Detector System (SPD)

    CERN Document Server

    Kluge, A; Antinori, Federico; Burns, M; Cali, I A; Campbell, M; Caselle, M; Ceresa, S; Dima, R; Elias, D; Fabris, D; Krivda, Marian; Librizzi, F; Manzari, Vito; Morel, M; Moretto, Sandra; Osmic, F; Pappalardo, G S; Pepato, Adriano; Pulvirenti, A; Riedler, P; Riggi, F; Santoro, R; Stefanini, G; Torcato De Matos, C; Turrisi, R; Tydesjo, H; Viesti, G; PH-EP

    2007-01-01

    The ALICE silicon pixel detector (SPD) comprises the two innermost layers of the ALICE inner tracker system. The SPD includes 120 detector modules (half-staves) each consisting of 10 ALICE pixel chips bump bonded to two silicon sensors and one multi-chip read-out module. Each pixel chip contains 8192 active cells, so that the total number of pixel cells in the SPD is ≈ 107. The on-detector read-out is based on a multi-chip-module containing 4 ASICs and an optical transceiver module. The constraints on material budget and detector module dimensions are very demanding.

  19. Accelerating ROP detector layout optimization

    International Nuclear Information System (INIS)

    Kastanya, D.; Fodor, B.

    2012-01-01

    The ADORE (Alternating Detector layout Optimization for REgional overpower protection system) algorithm for performing the optimization of regional overpower protection (ROP) system for CANDU® reactors have been recently developed. The simulated annealing (SA) stochastic optimization technique is utilized to come up with a quasi optimized detector layout for the ROP systems. Within each simulated annealing history, the objective function is calculated as a function of the trip set point (TSP) corresponding to the detector layout for that particular history. The evaluation of the TSP is done probabilistically using the ROVER-F code. Since during each optimization execution thousands of candidate detector layouts are evaluated, the overall optimization process is time consuming. Since for each ROVER-F evaluation the number of fuelling ripples controls the execution time, reducing the number of fuelling ripples used during the calculation of TSP will reduce the overall optimization execution time. This approach has been investigated and the results are presented in this paper. The challenge is to construct a set of representative fuelling ripples which will significantly speedup the optimization process while guaranteeing that the resulting detector layout has similar quality to the ones produced when the complete set of fuelling ripples is employed. Results presented in this paper indicate that a speedup of up to around 40 times is attainable when this approach is utilized. (author)

  20. Science with low temperature detectors

    International Nuclear Information System (INIS)

    Sadoulet, B.; Lawrence Berkeley National Lab., CA; California Univ., Berkeley

    1996-01-01

    The novel technique of particle detection with low temperature detectors opens a number of new scientific opportunities. We review some of these, focusing on three generic applications: far infrared bolometry taking as an example the cosmic microwave background, X-ray spectroscopy for astrophysics and biological applications, and massive calorimeters for dark matter searches and neutrino physics. (orig.)

  1. The GRANDE detector

    International Nuclear Information System (INIS)

    Adams, A.; Bond, R.; Coleman, L.; Rollefson, A.; Wold, D.; Bratton, C.B.; Gurr, H.; Kropp, W.; Nelson, M.; Price, L.R.; Reines, F.; Schultz, J.; Sobel, H.; Svoboda, R.; Yodh, G.; Burnett, T.; Chaloupka, V.; Wilkes, R.J.; Cherry, M.; Ellison, S.B.; Guzik, T.G.; Wefel, J.; Gaidos, J.; Loeffler, F.; Sembroski, G.; Wilson, C.; Goodman, J.; Haines, T.J.; Kielczewska, D.; Lane, C.; Steinberg, R.; Lieber, M.; Nagle, D.; Potter, M.; Tripp, R.

    1990-01-01

    In this paper we present a detector facility which meets the requirements outlined above for a next-generation instrument. GRANDE (Gamma Ray and Neutrino DEtector) is an imaging, water Cerenkov detector, which combines in one facility an extensive air shower array and a high-energy neutrino detector. (orig.)

  2. 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

  3. Results from a 64-pixel PIN-diode detector system for low-energy beta-electrons

    Energy Technology Data Exchange (ETDEWEB)

    Wuestling, Sascha, E-mail: sascha.wuestling@kit.ed [Forschungszentrum Karlsruhe, Institut fuer Prozessdatenverarbeitung und Elektronik, Postfach 3640, 76021 Karlsruhe (Germany); Fraenkle, F.; Habermehl, F.; Renschler, P. [Universitaet Karlsruhe - TH, Institut fuer Experimentelle Kernphysik, Postfach 6980, 76128 Karlsruhe (Germany); Steidl, M [Forschungszentrum Karlsruhe, Institut fuer Kernphysik, Postfach 3640, 76021 Karlsruhe (Germany)

    2010-12-11

    The KATRIN neutrino mass experiment is based on a precise energy measurement ({Delta}E/E=5x10{sup -5}) of electrons emerging from tritium beta decay (E{sub max}=18.6 keV). This is done by a large electrostatic retarding spectrometer (MAC-E Filter), which is followed by an electron detector. Key requirements for this detector are a large sensitive area ({approx}80 cm{sup 2}), a certain energy resolution ({Delta}E=600 eV - 18.6 keV) but also a certain spatial resolution ({approx}3 mm), which leads to a multi-pixel design. As a tentative design on the way to the final detector, but also for operational service on the so-called pre-spectrometer experiment, a detector system with a reduced size (16 cm{sup 2}) and a reduced pixel number (64), making use of a monolithic segmented silicon PIN diode, was designed and built. While the design and very first measurements have been presented in Wuestling et al. , this publication shows the operational performance of the detector system. The robust concept of the electronics allowed adaptation to mechanically different experimental setups. The spacial resolution of the detector system proved to be essential in examining Penning trap induced background and other effects in the pre-spectrometer experiment. The detector performance test runs include energy resolution and calibration, background rates, correlation between pixels (crosstalk), spatially resolved rate analysis, and a dead-layer measurement . The detector allows for background searches with a sensitivity as low as 1.3x10{sup -3} cps/cm{sup 2} in the energy range of 20 keV. This allows the pre-spectrometer to be characterized with e-gun illumination with a signal to background ratio of better than 10{sup 5} and the search for ultra low Penning discharge emissions.

  4. Results from a 64-pixel PIN-diode detector system for low-energy beta-electrons

    Science.gov (United States)

    Wuestling, Sascha; Fraenkle, F.; Habermehl, F.; Renschler, P.; Steidl, M.

    2010-12-01

    The KATRIN neutrino mass experiment is based on a precise energy measurement (Δ E/ E=5×10 -5) of electrons emerging from tritium beta decay ( Emax=18.6 keV). This is done by a large electrostatic retarding spectrometer (MAC-E Filter), which is followed by an electron detector. Key requirements for this detector are a large sensitive area (˜80 cm 2), a certain energy resolution (Δ E=600 eV @ 18.6 keV) but also a certain spatial resolution (˜3 mm), which leads to a multi-pixel design. As a tentative design on the way to the final detector, but also for operational service on the so-called pre-spectrometer experiment, a detector system with a reduced size (16 cm 2) and a reduced pixel number (64), making use of a monolithic segmented silicon PIN diode, was designed and built. While the design and very first measurements have been presented in Wuestling et al. [6], this publication shows the operational performance of the detector system. The robust concept of the electronics allowed adaptation to mechanically different experimental setups. The spacial resolution of the detector system proved to be essential in examining Penning trap induced background and other effects in the pre-spectrometer experiment. The detector performance test runs include energy resolution and calibration, background rates, correlation between pixels (crosstalk), spatially resolved rate analysis, and a dead-layer measurement [7]. The detector allows for background searches with a sensitivity as low as 1.3×10 -3 cps/cm 2 in the energy range of 20 keV. This allows the pre-spectrometer to be characterized with e-gun illumination with a signal to background ratio of better than 10 5 and the search for ultra low Penning discharge emissions.

  5. Test of GERDA Phase II detector assembly

    Energy Technology Data Exchange (ETDEWEB)

    Bode, Tobias; Gusev, Konstantin [Technische Universitaet Muenchen (Germany); Schwingenheuer, Bernhard; Wagner, Victoria [Max-Planck Institut fuer Kernphysik, Heidelberg (Germany); Collaboration: GERDA-Collaboration

    2014-07-01

    The GERDA experiment searches for the lepton number violating neutrinoless double beta decay (0νββ) of {sup 76}Ge. The experiment uses HPGe detectors enriched in {sup 76}Ge as source and detection material. In GERDA Phase I five BEGe detectors were operated successfully. These detectors are distinguished for improved energy resolution and enhanced pulse shape discrimination (PSD) against background events. In Phase II additional 25 BEGe detectors will be installed. New electronics and radio-pure low-mass holders were specially designed for Phase II. Prior to the installation in GERDA all BEGe detectors are tested in their final assembly in the LNGS underground laboratory. This talk presents the mechanics and performance of the GERDA Phase II detector assembly.

  6. Time-Resolved Emission Spectroscopic Study of Laser-Induced Steel Plasmas

    International Nuclear Information System (INIS)

    Shah, M. L.; Pulhani, A. K.; Suri, B. M.; Gupta, G. P.

    2013-01-01

    Laser-induced steel plasma is generated by focusing a Q-switched Nd:YAG visible laser (532 nm wavelength) with an irradiance of ∼ 1 × 10 9 W/cm 2 on a steel sample in air at atmospheric pressure. An Echelle spectrograph coupled with a gateable intensified charge-coupled detector is used to record the plasma emissions. Using time-resolved spectroscopic measurements of the plasma emissions, the temperature and electron number density of the steel plasma are determined for many times of the detector delay. The validity of the assumption by the spectroscopic methods that the laser-induced plasma (LIP) is optically thin and is also in local thermodynamic equilibrium (LTE) has been evaluated for many delay times. From the temporal evolution of the intensity ratio of two Fe I lines and matching it with its theoretical value, the delay times where the plasma is optically thin and is also in LTE are found to be 800 ns, 900 ns and 1000 ns.

  7. Solid state detector design

    International Nuclear Information System (INIS)

    Gunarwan Prayitno; Ahmad Rifai

    2010-01-01

    Much has been charged particle detector radiation detector made by the industry, especially those engaged in the development of detection equipment and components. The development and further research will be made solid state detector with silicon material. To be able to detect charged particles (radiation), required the processing of silicon material into the detector material. The method used to make silicon detector material is a lithium evaporations. Having formed an intrinsic region contactor installation process, and with testing. (author)

  8. 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.

  9. A Figure-of-Merit for Beta Cell Detector Characterization

    Energy Technology Data Exchange (ETDEWEB)

    Foxe, Michael P. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Miller, Brian W. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Suarez, Rey [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hayes, James C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-09-02

    In order to decrease the minimum detectable activities (MDAs) of beta-gamma radioxenon detectors, it is important to increase the ability to resolve the individual isotopes. One proposed method for doing this is to increase the energy resolution of the beta cell through the use of silicon detectors. While silicon detectors can improve the energy resolution, it is accompanied with a decrease in detection efficiency compared to plastic scintillator beta cells. Due to the uncertainty on the impact of the competing variables, we have developed a figure-of-merit (FOM) capable of determining the impact of detector parameters on the MDAs. By utilizing the FOM to analyze different detectors, we are able to directly compare current and future detectors and estimate their impact on the radioxenon MDAs.

  10. Status of the digital pixel array detector for protein crystallography

    CERN Document Server

    Datte, P; Beuville, E; Endres, N; Druillole, F; Luo, L; Millaud, J E; Xuong, N H

    1999-01-01

    A two-dimensional photon counting digital pixel array detector is being designed for static and time resolved protein crystallography. The room temperature detector will significantly enhance monochromatic and polychromatic protein crystallographic through-put data rates by more than three orders of magnitude. The detector has an almost infinite photon counting dynamic range and exhibits superior spatial resolution when compared to present crystallographic phosphor imaging plates or phosphor coupled CCD detectors. The detector is a high resistivity N-type Si with a pixel pitch of 150x150 mu m, and a thickness of 300 mu m, and is bump bonded to an application specific integrated circuit. The event driven readout of the detector is based on the column architecture and allows an independent pixel hit rate above 1 million photons/s/pixel. The device provides energy discrimination and sparse data readout which yields minimal dead-time. This type of architecture allows a continuous (frameless) data acquisition, a f...

  11. Domestic smoke detectors - a radioactive waste problem

    International Nuclear Information System (INIS)

    Carter, M.W.

    1996-01-01

    A common form of domestic smoke detector is the ionization chamber smoke detector. A small radioactive source provides the ionization and when smoke enters the sensitive volume the change in voltage is sensed electronically. The use of domestic ionization chamber smoke detectors is widespread and is recommended by fire authorities and insurance companies. That one million such detectors were imported into New South Wales in 1994 is an indication of the numbers involved. The typical radioactive source in a domestic smoke detector is Am 241, which is regarded as one of the more hazardous radionuclides. If it is such a hazardous material, should it be allowed in the normal household without any control? Or, in a smoke detector, is it in a less hazardous form than assumed in the ICRP recommendations and do its benefits outweigh its possible risks? In spite of the apparent hazard of Am 241, the possession of the radioactive source in smoke detectors is generally exempt from any form of regulation. Waste regulations, however, set requirements for the disposal of Am 241 and these regulations can be interpreted as applying to smoke detectors. We appear to have a situation where a home owner can legally purchase any number of smoke detectors but when they fail there are codes of practice that prevent them being disposed of. On the other hand, smoke detectors have a direct life saving function and reports indicate that smoke detectors can reduce both injury and property damage by up to 50%. Do these benefits from the use of smoke detectors compensate for any radiological risk? (author)

  12. Gamma-ray standards for detector calibration

    International Nuclear Information System (INIS)

    Christmas, P.; Nichols, A.L.; Lorenz, A.

    1987-09-01

    The first official meeting of the IAEA Coordinated Research Programme on the Measurement and Evaluation of X- and Gamma-ray Standards for Detector Calibration was held in Rome from 11 to 13 June 1987. Work undertaken by the CRP members was reviewed in detail: specific problems in the evaluations were identified and actions placed on the participants to resolve these issues. (author). 3 tabs

  13. Report of the detector laboratory

    International Nuclear Information System (INIS)

    Lynen, U.; Stelzer, H.; Fischer, B.

    1975-01-01

    Parallel plate detectors with sizes up to 30 x 30 cm 2 have been built and time resolutions of 350 psec for α-particles and approximately 200 psec for 25 MeV 16 O have been obtained. For these detectors a fast preamplifier was developed. Two digital processers for multiplication and division of 13-bit numbers have been built. For a PDP 11/40 a program has been developed which allows the on- and off-line data analysis. (orig.) [de

  14. Automatic control of movable detectors

    International Nuclear Information System (INIS)

    Wassel, W.W.; Remley, G.W.

    1980-01-01

    An invention is described, relating to a microprocessor based control system for a plurality of movable detectors, e.g. a nuclear reactor flux mapping system, with new system architecture which increases system availability by preventing faults on any of the detection channels from disabling the remaining channels. The system has, say, four drive trains for a number of detectors. Functional separation is realized by having two channels control their associated two drive trains. Redundancy is provided by having dual channels for operator interface. Communications between the functionally separate channels is accomplished by employing two-ported memories in conjunction with multiple microprocessors. (author)

  15. Time resolved techniques: An overview

    International Nuclear Information System (INIS)

    Larson, B.C.; Tischler, J.Z.

    1990-06-01

    Synchrotron sources provide exceptional opportunities for carrying out time-resolved x-ray diffraction investigations. The high intensity, high angular resolution, and continuously tunable energy spectrum of synchrotron x-ray beams lend themselves directly to carrying out sophisticated time-resolved x-ray scattering measurements on a wide range of materials and phenomena. When these attributes are coupled with the pulsed time-structure of synchrotron sources, entirely new time-resolved scattering possibilities are opened. Synchrotron beams typically consist of sub-nanosecond pulses of x-rays separated in time by a few tens of nanoseconds to a few hundred nanoseconds so that these beams appear as continuous x-ray sources for investigations of phenomena on time scales ranging from hours down to microseconds. Studies requiring time-resolution ranging from microseconds to fractions of a nanosecond can be carried out in a triggering mode by stimulating the phenomena under investigation in coincidence with the x-ray pulses. Time resolution on the picosecond scale can, in principle, be achieved through the use of streak camera techniques in which the time structure of the individual x-ray pulses are viewed as quasi-continuous sources with ∼100--200 picoseconds duration. Techniques for carrying out time-resolved scattering measurements on time scales varying from picoseconds to kiloseconds at present and proposed synchrotron sources are discussed and examples of time-resolved studies are cited. 17 refs., 8 figs

  16. Hupa Numbers.

    Science.gov (United States)

    Bennett, Ruth, Ed.; And Others

    An introduction to the Hupa number system is provided in this workbook, one in a series of numerous materials developed to promote the use of the Hupa language. The book is written in English with Hupa terms used only for the names of numbers. The opening pages present the numbers from 1-10, giving the numeral, the Hupa word, the English word, and…

  17. Triangular Numbers

    Indian Academy of Sciences (India)

    Admin

    Triangular number, figurate num- ber, rangoli, Brahmagupta–Pell equation, Jacobi triple product identity. Figure 1. The first four triangular numbers. Left: Anuradha S Garge completed her PhD from. Pune University in 2008 under the supervision of Prof. S A Katre. Her research interests include K-theory and number theory.

  18. Proth Numbers

    Directory of Open Access Journals (Sweden)

    Schwarzweller Christoph

    2015-02-01

    Full Text Available In this article we introduce Proth numbers and prove two theorems on such numbers being prime [3]. We also give revised versions of Pocklington’s theorem and of the Legendre symbol. Finally, we prove Pepin’s theorem and that the fifth Fermat number is not prime.

  19. Sagan numbers

    OpenAIRE

    Mendonça, J. Ricardo G.

    2012-01-01

    We define a new class of numbers based on the first occurrence of certain patterns of zeros and ones in the expansion of irracional numbers in a given basis and call them Sagan numbers, since they were first mentioned, in a special case, by the North-american astronomer Carl E. Sagan in his science-fiction novel "Contact." Sagan numbers hold connections with a wealth of mathematical ideas. We describe some properties of the newly defined numbers and indicate directions for further amusement.

  20. Source localization with an advanced gravitational wave detector network

    International Nuclear Information System (INIS)

    Fairhurst, Stephen

    2011-01-01

    We derive an expression for the accuracy with which sources can be localized using a network of gravitational wave detectors. The result is obtained via triangulation, using timing accuracies at each detector and is applicable to a network with any number of detectors. We use this result to investigate the ability of advanced gravitational wave detector networks to accurately localize signals from compact binary coalescences. We demonstrate that additional detectors can significantly improve localization results and illustrate our findings with networks comprised of the advanced LIGO, advanced Virgo and LCGT. In addition, we evaluate the benefits of relocating one of the advanced LIGO detectors to Australia.

  1. Testing 144- and 256-crystal BGO block detectors

    International Nuclear Information System (INIS)

    Rogers, J.G.; Nutt, R.; Andreaco, M.; Williams, C.W.

    1994-01-01

    New block detectors have been fabricated incorporating large numbers of small crystals. The authors evaluate and compare the performance of the new detectors with a standard 64-crystal block detector from Siemens-CTI. The new detectors demonstrate greatly improved imaging capability for 511 keV gamma rays. Future PET tomographs incorporating such detectors should produce substantially better volume images with little increase in tomograph manufacturing costs. The detectors will require a new type of automatic calibration procedure. Various such procedures have been tested and are discussed. A technique using higher energy gamma rays has shown special promise

  2. Improvement of the detector resolution in X-ray spectrometry by using the maximum entropy method

    International Nuclear Information System (INIS)

    Fernández, Jorge E.; Scot, Viviana; Giulio, Eugenio Di; Sabbatucci, Lorenzo

    2015-01-01

    In every X-ray spectroscopy measurement the influence of the detection system causes loss of information. Different mechanisms contribute to form the so-called detector response function (DRF): the detector efficiency, the escape of photons as a consequence of photoelectric or scattering interactions, the spectrum smearing due to the energy resolution, and, in solid states detectors (SSD), the charge collection artifacts. To recover the original spectrum, it is necessary to remove the detector influence by solving the so-called inverse problem. The maximum entropy unfolding technique solves this problem by imposing a set of constraints, taking advantage of the known a priori information and preserving the positive-defined character of the X-ray spectrum. This method has been included in the tool UMESTRAT (Unfolding Maximum Entropy STRATegy), which adopts a semi-automatic strategy to solve the unfolding problem based on a suitable combination of the codes MAXED and GRAVEL, developed at PTB. In the past UMESTRAT proved the capability to resolve characteristic peaks which were revealed as overlapped by a Si SSD, giving good qualitative results. In order to obtain quantitative results, UMESTRAT has been modified to include the additional constraint of the total number of photons of the spectrum, which can be easily determined by inverting the diagonal efficiency matrix. The features of the improved code are illustrated with some examples of unfolding from three commonly used SSD like Si, Ge, and CdTe. The quantitative unfolding can be considered as a software improvement of the detector resolution. - Highlights: • Radiation detection introduces distortions in X- and Gamma-ray spectrum measurements. • UMESTRAT is a graphical tool to unfold X- and Gamma-ray spectra. • UMESTRAT uses the maximum entropy method. • UMESTRAT’s new version produces unfolded spectra with quantitative meaning. • UMESTRAT is a software tool to improve the detector resolution.

  3. Time-resolved ESR spectroscopy

    International Nuclear Information System (INIS)

    Beckert, D.

    1986-06-01

    The time-resolved ESR spectroscopy is one of the modern methods in radiospectroscopy and plays an important role in solving various problems in chemistry and biology. Proceeding from the basic ideas of time-resolved ESR spectroscopy the experimental equipment is described generally including the equipment developed at the Central Institute of Isotope and Radiation Research. The experimental methods applied to the investigation of effects of chemically induced magnetic polarization of electrons and to kinetic studies of free radicals in polymer systems are presented. The theory of radical pair mechanism is discussed and theoretical expressions are summarized in a computer code to compute the theoretical polarization for each pair of the radicals

  4. MD#1182: Calibration of diamond particle detectors in IP6

    CERN Document Server

    Valette, Matthieu; Lindstrom, Bjorn Hans Filip; Wiesner, Christoph

    2017-01-01

    In case of an asynchronous beam dump with a fully filled LHC machine it is expected that all standard ionisation chamber Beam Loss Monitors (IC BLM) around the LHC dumping region in IP6 will be saturated. Diamond Beam Loss Monitors (dBLM) were therefore installed next to the movable dump protection absorber (TCDQ) downstream of the extraction kickers. These detectors allow resolving losses at a nanosecond timescale and with an dynamic range of several orders of magnitude; thus, allowing to know the number of nominal bunches impacting the TCDQ. After a first series of calibrations using asynchronous beam dump tests, an experiment was conducted during MD#1182 to demonstrate the possibility of resolving a nominal bunch hitting the TCDQ. The impact parameter of the bunches on the TCDQ was first scanned using probe bunches with lower intensity then tests were done with nominal bunches (1.1e11 p/bunch) at injection energy. High energy calibration of the losses was also attempted unsuccessfully. Due to different beh...

  5. High precision thermal neutron detectors

    Energy Technology Data Exchange (ETDEWEB)

    Radeka, V.; Schaknowski, N.A.; Smith, G.C.; Yu, B. [Brookhaven National Laboratory, Upton, NY (United States)

    1994-12-31

    Two-dimensional position sensitive detectors are indispensable in neutron diffraction experiments for determination of molecular and crystal structures in biology, solid-state physics and polymer chemistry. Some performance characteristics of these detectors are elementary and obvious, such as the position resolution, number of resolution elements, neutron detection efficiency, counting rate and sensitivity to gamma-ray background. High performance detectors are distinguished by more subtle characteristics such as the stability of the response (efficiency) versus position, stability of the recorded neutron positions, dynamic range, blooming or halo effects. While relatively few of them are needed around the world, these high performance devices are sophisticated and fairly complex, their development requires very specialized efforts. In this context, we describe here a program of detector development, based on {sup 3}He filled proportional chambers, which has been underway for some years at the Brookhaven National Laboratory. Fundamental approaches and practical considerations are outlined that have resulted in a series of high performance detectors with the best known position resolution, position stability, uniformity of response and reliability over time, for devices of this type.

  6. Report on Advanced Detector Development

    Energy Technology Data Exchange (ETDEWEB)

    James K. Jewell

    2012-09-01

    Neutron, gamma and charged particle detection improvements are key to supporting many of the foreseen measurements and systems envisioned in the R&D programs and the future fuel cycle requirements, such as basic nuclear physics and data, modeling and simulation, reactor instrumentation, criticality safety, materials management and safeguards. This task will focus on the developmental needs of the FCR&D experimental programs, such as elastic/inelastic scattering, total cross sections and fission neutron spectra measurements, and will leverage a number of existing neutron detector development efforts and programs, such as those at LANL, PNNL, INL, and IAC as well as those at many universities, some of whom are funded under NE grants and contracts. Novel materials and fabrication processes combined with state-of-the-art electronics and computing provide new opportunities for revolutionary detector systems that will be able to meet the high precision needs of the program. This work will be closely coordinated with the Nuclear Data Crosscut. The Advanced Detector Development effort is a broadly-focused activity that supports the development of improved nuclear data measurements and improved detection of nuclear reactions and reactor conditions. This work supports the design and construction of large-scale, multiple component detectors to provide nuclear reaction data of unprecedented quality and precision. Examples include the Time Projection Chamber (TPC) and the DANCE detector at LANL. This work also supports the fabrication and end-user application of novel scintillator materials detection and monitoring.

  7. Interferometric direction finding with a metamaterial detector

    Energy Technology Data Exchange (ETDEWEB)

    Venkatesh, Suresh; Schurig, David, E-mail: david.schurig@utah.edu [Department of Electrical and Computer Engineering, University of Utah, Salt Lake City, Utah 84112 (United States); Shrekenhamer, David; Padilla, Willie [Department of Physics, Boston College, Chestnut Hill, Massachusetts 02467 (United States); Xu, Wangren; Sonkusale, Sameer [Department of Electrical and Computer Engineering, Tufts University, Medford, Massachusetts 02155 (United States)

    2013-12-16

    We present measurements and analysis demonstrating useful direction finding of sources in the S band (2–4 GHz) using a metamaterial detector. An augmented metamaterial absorber that supports magnitude and phase measurement of the incident electric field, within each unit cell, is described. The metamaterial is implemented in a commercial printed circuit board process with off-board back-end electronics. We also discuss on-board back-end implementation strategies. Direction finding performance is analyzed for the fabricated metamaterial detector using simulated data and the standard algorithm, MUtiple SIgnal Classification. The performance of this complete system is characterized by its angular resolution as a function of radiation density at the detector. Sources with power outputs typical of mobile communication devices can be resolved at kilometer distances with sub-degree resolution and high frame rates.

  8. Device simulation and optimization of laterally-contacted-unipolar-nuclear detector

    CERN Document Server

    Lee, E Y

    1999-01-01

    Unipolar gamma-ray detectors offer the possibility of enhanced energy resolution and detection sensitivity over the conventional planar detectors. However, these detectors are difficult to understand and to fabricate, due to their three-dimensional geometry and multiple electrodes. Computer simulation offers a powerful way to design and to optimize these detectors, by giving the internal electric fields, weighting potentials, and spatially resolved detector responses. Simulation and optimization of an unipolar gamma-ray detector called laterally-contacted-unipolar-nuclear detector (LUND) are shown. For 662 keV gamma-rays from a sup 1 sup 3 sup 7 Cs source, the simulation and optimization of LUND resulted in improvement in the energy resolution from 1.6% to 1.3% and improvement in the active detector volume from 4% to 38% of the total detector volume.

  9. Eulerian numbers

    CERN Document Server

    Petersen, T Kyle

    2015-01-01

    This text presents the Eulerian numbers in the context of modern enumerative, algebraic, and geometric combinatorics. The book first studies Eulerian numbers from a purely combinatorial point of view, then embarks on a tour of how these numbers arise in the study of hyperplane arrangements, polytopes, and simplicial complexes. Some topics include a thorough discussion of gamma-nonnegativity and real-rootedness for Eulerian polynomials, as well as the weak order and the shard intersection order of the symmetric group. The book also includes a parallel story of Catalan combinatorics, wherein the Eulerian numbers are replaced with Narayana numbers. Again there is a progression from combinatorics to geometry, including discussion of the associahedron and the lattice of noncrossing partitions. The final chapters discuss how both the Eulerian and Narayana numbers have analogues in any finite Coxeter group, with many of the same enumerative and geometric properties. There are four supplemental chapters throughout, ...

  10. Positron annihilation imaging device using multiple offset rings of detectors

    International Nuclear Information System (INIS)

    Thompson, C.J.

    1982-01-01

    A means is provided for recording more than one tomographic image simultaneously through different cross-sections of a patient, using positron emission tomography. Separate rings of detectors are used to construct every odd-numbered slice, and coincident events that occur between adjacent rings of detectors provide a center or even-numbered slice. Detector rings are offset with respect to one another by half the angular separation of the detectors, allowing an image to be reconstructed from the central slice without the necessity of physically rotating the detector array while accumulating data

  11. MUON DETECTORS: DT

    CERN Multimedia

    Marco Dallavalle

    2012-01-01

      Although the year 2012 is the third year without access to the chambers and the Front-End electronics, the fraction of good channels is still very high at 99.1% thanks also to the constant care provided by the on-site operation team. The downtime caused to CMS as a consequence of DT failures is to-date <2%. The intervention on the LV power supplies, which required a large number of CAEN modules (137 A3050, 13 A3100, and 3 MAO) to be removed from the detector, reworked and tested during this Year-End Technical Stop, can now, after a few months of stable operation of the LV, be declared to have solved once-and-for-all the persistent problem with the overheating LV Anderson connectors. Another piece of very good news is that measurements of the noise from single-hit rate outside the drift-time box as a function of the LHC luminosity show that the noise rate and distribution are consistent with expectations of the simulations in the Muon TDR, which have guided the detector design and constru...

  12. The status of detectors at the SSC

    International Nuclear Information System (INIS)

    Stefanski, R.

    1990-09-01

    The announcement of the location of the SSC at the site near Waxahachie, Texas was made in January, 1989. Since then a great many important steps have been taken toward the start of the new Laboratory. Some 900 people have been brought to the site as the starting nucleus of the staff that will ultimate number about 2200. A design baseline has been completed that includes a conceptual design for the accelerator, and the detectors. Also, the process has begun to determine the configuration of detectors that will be built for the SSC. This process has several steps, and now the first of these has been taken: The detector collaborations have submitted the Expression of Interest to the Laboratory. These were reviewed by Laboratory management and the Physics Advisory Committee in July, 1990 and recommendations were made to the collaborations. Decisions were deferred for all of the detectors. But perhaps the most significant recommendation was the request to reduce the size and cost of the general purpose detectors. The detector collaborations are now reviewing their initial designs to prepare for the Letters of Intent, the next step in the detector planning process. This is clearly a difficult and crucial step in that the redesign of the detectors must be done with minimal reduction in detector quality. It is an interesting time in the development of the new laboratory, and a crucial time for the ultimate physics that will be done at the SSC

  13. Time-resolved quantitative phosphoproteomics

    DEFF Research Database (Denmark)

    Verano-Braga, Thiago; Schwämmle, Veit; Sylvester, Marc

    2012-01-01

    proteins involved in the Ang-(1-7) signaling, we performed a mass spectrometry-based time-resolved quantitative phosphoproteome study of human aortic endothelial cells (HAEC) treated with Ang-(1-7). We identified 1288 unique phosphosites on 699 different proteins with 99% certainty of correct peptide...

  14. Time-resolved vibrational spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Tokmakoff, Andrei [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Champion, Paul [Northeastern Univ., Boston, MA (United States); Heilweil, Edwin J. [National Inst. of Standards and Technology (NIST), Boulder, CO (United States); Nelson, Keith A. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Ziegler, Larry [Boston Univ., MA (United States)

    2009-05-14

    This document contains the Proceedings from the 14th International Conference on Time-Resolved Vibrational Spectroscopy, which was held in Meredith, NH from May 9-14, 2009. The study of molecular dynamics in chemical reaction and biological processes using time-resolved spectroscopy plays an important role in our understanding of energy conversion, storage, and utilization problems. Fundamental studies of chemical reactivity, molecular rearrangements, and charge transport are broadly supported by the DOE's Office of Science because of their role in the development of alternative energy sources, the understanding of biological energy conversion processes, the efficient utilization of existing energy resources, and the mitigation of reactive intermediates in radiation chemistry. In addition, time-resolved spectroscopy is central to all fiveof DOE's grand challenges for fundamental energy science. The Time-Resolved Vibrational Spectroscopy conference is organized biennially to bring the leaders in this field from around the globe together with young scientists to discuss the most recent scientific and technological advances. The latest technology in ultrafast infrared, Raman, and terahertz spectroscopy and the scientific advances that these methods enable were covered. Particular emphasis was placed on new experimental methods used to probe molecular dynamics in liquids, solids, interfaces, nanostructured materials, and biomolecules.

  15. Resolving Ethical Issues at School

    Science.gov (United States)

    Benninga, Jacques S.

    2013-01-01

    Although ethical dilemmas are a constant in teachers' lives, the profession has offered little in the way of training to help teachers address such issues. This paper presents a framework, based on developmental theory, for resolving professional ethical dilemmas. The Four-Component Model of Moral Maturity, when used in conjunction with a…

  16. Drift Chambers detectors; Detectores de deriva

    Energy Technology Data Exchange (ETDEWEB)

    Duran, I; Martinez laso, L

    1989-07-01

    We present here a review of High Energy Physics detectors based on drift chambers. The ionization, drift diffusion, multiplication and detection principles are described. Most common drift media are analysed, and a classification of the detectors according to its geometry is done. Finally the standard read-out methods are displayed and the limits of the spatial resolution are discussed. (Author) 115 refs.

  17. Transfinite Numbers

    Indian Academy of Sciences (India)

    Transfinite Numbers. What is Infinity? S M Srivastava. In a series of revolutionary articles written during the last quarter of the nineteenth century, the great Ger- man mathematician Georg Cantor removed the age-old mistrust of infinity and created an exceptionally beau- tiful and useful theory of transfinite numbers. This is.

  18. Spatially resolved remote measurement of temperature by neutron resonance absorption

    Energy Technology Data Exchange (ETDEWEB)

    Tremsin, A.S., E-mail: ast@ssl.berkeley.edu [Space Sciences Laboratory, University of California at Berkeley, 7 Gauss Way, Berkeley, CA 94720 (United States); Kockelmann, W.; Pooley, D.E. [STFC, Rutherford Appleton Laboratory, ISIS Facility, Didcot OX11 0QX (United Kingdom); Feller, W.B. [NOVA Scientific, Inc., 10 Picker Road, Sturbridge, MA 01566 (United States)

    2015-12-11

    Deep penetration of neutrons into most engineering materials enables non-destructive studies of their bulk properties. The existence of sharp resonances in neutron absorption spectra enables isotopically-resolved imaging of elements present in a sample, as demonstrated by previous studies. At the same time the Doppler broadening of resonance peaks provides a method of remote measurement of temperature distributions within the same sample. This technique can be implemented at a pulsed neutron source with a short initial pulse allowing for the measurement of the energy of each registered neutron by the time of flight technique. A neutron counting detector with relatively high timing and spatial resolution is used to demonstrate the possibility to obtain temperature distributions across a 100 µm Ta foil with ~millimeter spatial resolution. Moreover, a neutron transmission measurement over a wide energy range can provide spatially resolved sample information such as temperature, elemental composition and microstructure properties simultaneously.

  19. A sub-millimeter resolution PET detector module using a multi-pixel photon counter array

    International Nuclear Information System (INIS)

    Song, Tae Yong; Wu Heyu; Komarov, Sergey; Tai, Yuan-Chuan; Siegel, Stefan B

    2010-01-01

    A PET block detector module using an array of sub-millimeter lutetium oxyorthosilicate (LSO) crystals read out by an array of surface-mount, semiconductor photosensors has been developed. The detector consists of a LSO array, a custom acrylic light guide, a 3 x 3 multi-pixel photon counter (MPPC) array (S10362-11-050P, Hamamatsu Photonics, Japan) and a readout board with a charge division resistor network. The LSO array consists of 100 crystals, each measuring 0.8 x 0.8 x 3 mm 3 and arranged in 0.86 mm pitches. A Monte Carlo simulation was used to aid the design and fabrication of a custom light guide to control distribution of scintillation light over the surface of the MPPC array. The output signals of the nine MPPC are multiplexed by a charge division resistor network to generate four position-encoded analog outputs. Flood image, energy resolution and timing resolution measurements were performed using standard NIM electronics. The linearity of the detector response was investigated using gamma-ray sources of different energies. The 10 x 10 array of 0.8 mm LSO crystals was clearly resolved in the flood image. The average energy resolution and standard deviation were 20.0% full-width at half-maximum (FWHM) and ±5.0%, respectively, at 511 keV. The timing resolution of a single MPPC coupled to a LSO crystal was found to be 857 ps FWHM, and the value for the central region of detector module was 1182 ps FWHM when ±10% energy window was applied. The nonlinear response of a single MPPC when used to read out a single LSO was observed among the corner crystals of the proposed detector module. However, the central region of the detector module exhibits significantly less nonlinearity (6.5% for 511 keV). These results demonstrate that (1) a charge-sharing resistor network can effectively multiplex MPPC signals and reduce the number of output signals without significantly degrading the performance of a PET detector and (2) a custom light guide to permit light sharing

  20. Mica fission detectors

    International Nuclear Information System (INIS)

    Wong, C.; Anderson, J.D.; Hansen, L.; Lehn, A.V.; Williamson, M.A.

    1977-01-01

    The present development status of the mica fission detectors is summarized. It is concluded that the techniques have been refined and developed to a state such that the mica fission counters are a reliable and reproducible detector for fission events

  1. Barrier Infrared Detector (BIRD)

    Data.gov (United States)

    National Aeronautics and Space Administration — A recent breakthrough in MWIR detector design, has resulted in a high operating temperature (HOT) barrier infrared detector (BIRD) that is capable of spectral...

  2. Simulating detectors dead time

    International Nuclear Information System (INIS)

    Rustom, Ibrahim Farog Ibrahim

    2015-06-01

    Nuclear detectors are used in all aspects of nuclear measurements. All nuclear detectors are characterized by their dead time i.e. the time needed by a detector to recover from a previous incident. A detector dead time influences measurements taken by a detector and specially when measuring high decay rate (>) where is the detector dead time. Two models are usually used to correct for the dead time effect: the paralayzable and the non-paralayzable models. In the current work we use Monte Carlo simulation techniques to simulate radioactivity and the effect of dead time and the count rate of a detector with a dead time =5x10 - 5s assuming the non-paralayzable model. The simulation indicates that assuming a non -paralayzable model could be used to correct for decay rate measured by a detector. The reliability of the non-paralayzable model to correct the measured decay rate could be gauged using the Monte Carlo simulation. (Author)

  3. Forward tracking detectors

    Indian Academy of Sciences (India)

    Abstract. Forward tracking is an essential part of a detector at the international linear collider (ILC). The requirements for forward tracking are explained and the proposed solutions in the detector concepts are shown.

  4. The OSMOND detector

    Energy Technology Data Exchange (ETDEWEB)

    Bateman, J.E. [Technology Dept. Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Oxford, Oxfordshire, OX11 0QX (United Kingdom); Dalgliesh, R. [ISIS Dept. Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Oxford, Oxfordshire, OX11 0QX (United Kingdom); Duxbury, D.M., E-mail: dom.duxbury@stfc.ac.uk [Technology Dept. Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Oxford, Oxfordshire, OX11 0QX (United Kingdom); Helsby, W.I. [Science and Technology Facilities Council, Daresbury Laboratory, Keckwick Lane, Daresbury, Warrington WA4 4AD (United Kingdom); Holt, S.A.; Kinane, C.J. [ISIS Dept. Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Oxford, Oxfordshire, OX11 0QX (United Kingdom); Marsh, A.S. [Diamond Light Source LTD, Harwell Science and Innovation Campus, Diamond House, Chilton, Didcot, Oxfordshire, OX11 0DE (United Kingdom); Rhodes, N.J.; Schooneveld, E.M. [ISIS Dept. Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Oxford, Oxfordshire, OX11 0QX (United Kingdom); Spill, E.J.; Stephenson, R. [Technology Dept. Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Oxford, Oxfordshire, OX11 0QX (United Kingdom)

    2013-01-11

    The development and testing of the Off Specular MicrOstrip Neutron Detector (OSMOND) is described. Based on a microstrip gas chamber the aim of the project was to produce a high counting rate detector capable of replacing the existing rate limited scintillator detectors currently in use on the CRISP reflectometer for off specular reflectometry experiments. The detector system is described together with results of neutron beam tests carried out at the ISIS spallation neutron source.

  5. Chocolate Numbers

    OpenAIRE

    Ji, Caleb; Khovanova, Tanya; Park, Robin; Song, Angela

    2015-01-01

    In this paper, we consider a game played on a rectangular $m \\times n$ gridded chocolate bar. Each move, a player breaks the bar along a grid line. Each move after that consists of taking any piece of chocolate and breaking it again along existing grid lines, until just $mn$ individual squares remain. This paper enumerates the number of ways to break an $m \\times n$ bar, which we call chocolate numbers, and introduces four new sequences related to these numbers. Using various techniques, we p...

  6. Number theory

    CERN Document Server

    Andrews, George E

    1994-01-01

    Although mathematics majors are usually conversant with number theory by the time they have completed a course in abstract algebra, other undergraduates, especially those in education and the liberal arts, often need a more basic introduction to the topic.In this book the author solves the problem of maintaining the interest of students at both levels by offering a combinatorial approach to elementary number theory. In studying number theory from such a perspective, mathematics majors are spared repetition and provided with new insights, while other students benefit from the consequent simpl

  7. WORKSHOP: Scintillating fibre detectors

    International Nuclear Information System (INIS)

    Anon.

    1989-01-01

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

  8. Shielded regenerative neutron detector

    International Nuclear Information System (INIS)

    Terhune, J.H.; Neissel, J.P.

    1978-01-01

    An ion chamber type neutron detector is disclosed which has a greatly extended lifespan. The detector includes a fission chamber containing a mixture of active and breeding material and a neutron shielding material. The breeding and shielding materials are selected to have similar or substantially matching neutron capture cross-sections so that their individual effects on increased detector life are mutually enhanced

  9. The CAPRICE RICH detector

    Energy Technology Data Exchange (ETDEWEB)

    Basini, G. [INFN, Laboratori Nazionali di Frascati, Rome (Italy); Codino, A.; Grimani, C. [Perugia Univ. (Italy)]|[INFN, Perugia (Italy); De Pascale, M.P. [Rome Univ. `Tor Vergata` (Italy). Dip. di Fisica]|[INFN, Sezione Univ. `Tor Vergata` Rome (Italy); Cafagna, F. [Bari Univ. (Italy)]|[INFN, Bari (Italy); Golden, R.L. [New Mexico State Univ., Las Cruces, NM (United States). Particle Astrophysics Lab.; Brancaccio, F.; Bocciolini, M. [Florence Univ. (Italy)]|[INFN, Florence (Italy); Barbiellini, G.; Boezio, M. [Trieste Univ. (Italy)]|[INFN, Trieste (Italy)

    1995-09-01

    A compact RICH detector has been developed and used for particle identification in a balloon borne spectrometer to measure the flux of antimatter in the cosmic radiation. This is the first RICH detector ever used in space experiments that is capable of detecting unit charged particles, such as antiprotons. The RICH and all other detectors performed well during the 27 hours long flight.

  10. Self powered neutron detectors

    International Nuclear Information System (INIS)

    Gopalan, C.S.; Ramachandra Rao, M.N.; Ingale, A.D.

    1976-01-01

    Two types of self powered neutron detectors used for in-core flux measurements are described. The characteristics of the various detectors, with emitters Rh, V, Co, Py are presented. Details about the fabrication of these detectors are given. (A.K.)

  11. The JADE muon detector

    International Nuclear Information System (INIS)

    Allison, J.; Armitage, J.C.M.; Baines, J.T.M.; Ball, A.H.; Bamford, G.; Barlow, R.J.; Bowdery, C.K.; Chrin, J.T.M.; Duerdoth, I.P.; Glendinning, I.; Greenshaw, T.; Hassard, J.F.; Hill, P.; King, B.T.; Loebinger, F.K.; Macbeth, A.A.; McCann, H.; Mercer, D.; Mills, H.E.; Murphy, P.G.; Prosper, H.B.; Rowe, P.; Stephens, K.

    1985-01-01

    The JADE muon detector consists of 618 planar drift chambers interspersed between layers of hadron absorber. This paper gives a detailed description of the construction and operation of the detector as a whole and discusses the properties of the drift chambers. The muon detector has been operating successfully at PETRA for five years. (orig.)

  12. Economical stabilized scintillation detector

    International Nuclear Information System (INIS)

    Anshakov, O.M.; Chudakov, V.A.; Gurinovich, V.I.

    1983-01-01

    An economical scintillation detector with the stabilization system of an integral type is described. Power consumed by the photomultiplier high-voltage power source is 40 mW, energy resolution is not worse than 9%. The given detector is used in a reference detector of a digital radioisotope densimeter for light media which is successfully operating for several years

  13. Gas filled detectors

    International Nuclear Information System (INIS)

    Stephan, C.

    1993-01-01

    The main types of gas filled nuclear detectors: ionization chambers, proportional counters, parallel-plate avalanche counters (PPAC) and microstrip detectors are described. New devices are shown. A description of the processes involved in such detectors is also given. (K.A.) 123 refs.; 25 figs.; 3 tabs

  14. HP Ge planar detectors

    International Nuclear Information System (INIS)

    Gornov, M.G.; Gurov, Yu.B.; Soldatov, A.M.; Osipenko, B.P.; Yurkowski, J.; Podkopaev, O.I.

    1989-01-01

    Parameters of planar detectors manufactured of HP Ge are presented. The possibilities to use multilayer spectrometers on the base of such semiconductor detectors for nuclear physics experiments are discussed. It is shown that the obtained detectors including high square ones have spectrometrical characteristics close to limiting possible values. 9 refs.; 3 figs.; 1 tab

  15. Nuclear detectors: principles and applications

    International Nuclear Information System (INIS)

    Belhadj, Marouane

    1999-01-01

    Nuclear technology is a vast domain. It has several applications, for instance in hydrology, it is used in the analysis of underground water, dating by carbon 14, Our study consists on representing the nuclear detectors based on their principle of functioning and their electronic constitution. However, because of some technical problems, we have not made a deepen study on their applications that could certainly have a big support on our subject. In spite of the existence of an equipment of high performance and technology in the centre, it remains to resolve the problem of control of instruments. Therefore, the calibration of these equipment remains the best guaranteed of a good quality of the counting. Besides, it allows us to approach the influence of the external and internal parameters on the equipment and the reasons of errors of measurements, to introduce equivalent corrections. (author). 22 refs

  16. Time domain electromagnetic metal detectors

    International Nuclear Information System (INIS)

    Hoekstra, P.

    1996-01-01

    This presentation focuses on illustrating by case histories the range of applications and limitations of time domain electromagnetic (TDEM) systems for buried metal detection. Advantages claimed for TDEM metal detectors are: independent of instrument response (Geonics EM61) to surrounding soil and rock type; simple anomaly shape; mitigation of interference by ambient electromagnetic noise; and responsive to both ferrous and non-ferrous metallic targets. The data in all case histories to be presented were acquired with the Geonics EM61 TDEM system. Case histories are a test bed site on Molokai, Hawaii; Fort Monroe, Virginia; and USDOE, Rocky Flats Plant. The present limitations of this technology are: discrimination capabilities in terms of type of ordnance, and depth of burial is limited, and ability of resolving targets with small metallic ambient needs to be improved

  17. Nice numbers

    CERN Document Server

    Barnes, John

    2016-01-01

    In this intriguing book, John Barnes takes us on a journey through aspects of numbers much as he took us on a geometrical journey in Gems of Geometry. Similarly originating from a series of lectures for adult students at Reading and Oxford University, this book touches a variety of amusing and fascinating topics regarding numbers and their uses both ancient and modern. The author intrigues and challenges his audience with both fundamental number topics such as prime numbers and cryptography, and themes of daily needs and pleasures such as counting one's assets, keeping track of time, and enjoying music. Puzzles and exercises at the end of each lecture offer additional inspiration, and numerous illustrations accompany the reader. Furthermore, a number of appendices provides in-depth insights into diverse topics such as Pascal’s triangle, the Rubik cube, Mersenne’s curious keyboards, and many others. A theme running through is the thought of what is our favourite number. Written in an engaging and witty sty...

  18. Time- and energy resolved photoemission electron microscopy-imaging of photoelectron time-of-flight analysis by means of pulsed excitations

    International Nuclear Information System (INIS)

    Oelsner, Andreas; Rohmer, Martin; Schneider, Christian; Bayer, Daniela; Schoenhense, Gerd; Aeschlimann, Martin

    2010-01-01

    The present work enlightens the developments in time- and energy resolved photoemission electron microscopy over the past few years. We describe basic principles of the technique and demonstrate different applications. An energy- and time-filtering photoemission electron microscopy (PEEM) for real-time spectroscopic imaging can be realized either by a retarding field or hemispherical energy analyzer or by using time-of-flight optics with a delay line detector. The latter method has the advantage of no data loss at all as all randomly incoming particles are measured not only by position but also by time. This is of particular interest for pump-probe experiments in the femtosecond and attosecond time scale where space charge processes drastically limit the maximum number of photoemitted electrons per laser pulse. This work focuses particularly on time-of-flight analysis using a novel delay line detector. Time and energy resolved PEEM instruments with delay line detectors enable 4D imaging (x, y, Δt, E Kin ) on a true counting basis. This allows a broad range of applications from real-time observation of dynamic phenomena at surfaces to fs time-of-flight spectro-microscopy and even aberration correction. By now, these time-of-flight analysis instruments achieve intrinsic time resolutions of 108 ps absolute and 13.5 ps relative. Very high permanent measurement speeds of more than 4 million events per second in random detection regimes have been realized using a standard USB2.0 interface. By means of this performance, the time-resolved PEEM technique enables to display evolutions of spatially resolved (<25 nm) and temporal sliced images life on any modern computer. The method allows dynamics investigations of variable electrical, magnetic, and optical near fields at surfaces and great prospects in dynamical adaptive photoelectron optics. For dynamical processes in the ps time scale such as magnetic domain wall movements, the time resolution of the delay line detectors

  19. Enforcement actions: Significant actions resolved

    International Nuclear Information System (INIS)

    1994-03-01

    This compilation summarizes significant enforcement actions that have been resolved during one quarterly period (October - December 1993) and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to licensees with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication

  20. Enforcement actions: Significant actions resolved

    International Nuclear Information System (INIS)

    1992-11-01

    This compilation summarizes significant enforcement actions that have been resolved during one quarterly period (July - September 1992) and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to licensees with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication

  1. Radiation detectors laboratory

    International Nuclear Information System (INIS)

    Ramirez J, F.J.

    1997-01-01

    The Radiation detectors laboratory was established with the assistance of the International Atomic Energy Agency which gave this the responsibility to provide its services at National and regional level for Latin America and it is located at the ININ. The more expensive and delicate radiation detectors are those made of semiconductor, so it has been put emphasis in the use and repairing of these detectors type. The supplied services by this laboratory are: selection consultant, detectors installation and handling and associated systems. Installation training, preventive and corrective maintenance of detectors and detection systems calibration. (Author)

  2. The ATLAS Pixel Detector

    CERN Document Server

    Huegging, Fabian

    2006-06-26

    The contruction of the ATLAS Pixel Detector which is the innermost layer of the ATLAS tracking system is prgressing well. Because the pixel detector will contribute significantly to the ATLAS track and vertex reconstruction. The detector consists of identical sensor-chip-hybrid modules, arranged in three barrels in the centre and three disks on either side for the forward region. The position of the detector near the interaction point requires excellent radiation hardness, mechanical and thermal robustness, good long-term stability for all parts, combined with a low material budget. The final detector layout, new results from production modules and the status of assembly are presented.

  3. Microscope mode secondary ion mass spectrometry imaging with a Timepix detector.

    NARCIS (Netherlands)

    Kiss, A.; Jungmann, JH; Smith, D.F.; Heeren, R.M.A.

    2013-01-01

    In-vacuum active pixel detectors enable high sensitivity, highly parallel time- and space-resolved detection of ions from complex surfaces. For the first time, a Timepix detector assembly was combined with a secondary ion mass spectrometer for microscope mode secondary ion mass spectrometry (SIMS)

  4. CONTINUING THE DEVELOPMENT OF A 100 FEMTOSECOND X-RAY DETECTOR

    International Nuclear Information System (INIS)

    Zenghu Chang

    2005-01-01

    The detector is an x-ray streak camera running in accumulation mode for time resolved x-ray studies at the existing third generation synchrotron facilities and will also be used for the development and applications of the fourth generation x-ray sources. We have made significant progress on both the detector development and its applications at Synchrotron facilities

  5. Number names and number understanding

    DEFF Research Database (Denmark)

    Ejersbo, Lisser Rye; Misfeldt, Morten

    2014-01-01

    This paper concerns the results from the first year of a three-year research project involving the relationship between Danish number names and their corresponding digits in the canonical base 10 system. The project aims to develop a system to help the students’ understanding of the base 10 syste...... the Danish number names are more complicated than in other languages. Keywords: A research project in grade 0 and 1th in a Danish school, Base-10 system, two-digit number names, semiotic, cognitive perspectives....

  6. Radiation detectors laboratory

    International Nuclear Information System (INIS)

    Ramirez J, F.J.

    1996-01-01

    The National Institute for Nuclear Research has established a Radiation detector laboratory that has the possibility of providing to the consultants on the handling and applications of the nuclear radiation detectors. It has special equipment to repair the radiation detectors used in spectroscopy as the hyper pure Germanium for gamma radiation and the Lithium-silica for X-rays. There are different facilities in the laboratory that can become useful for other institutions that use radiation detectors. This laboratory was created to satisfy consultant services, training and repairing of the radiation detectors both in national and regional levels for Latin America. The laboratory has the following sections: Nuclear Electronic Instrumentation; where there are all kind of instruments for the measurement and characterization of detectors like multichannel analyzers of pulse height, personal computers, amplifiers and nuclear pulse preamplifiers, nuclear pulses generator, aleatories, computer programs for radiation spectra analysis, etc. High vacuum; there is a vacuum escape measurer, two high vacuum pumps to restore the vacuum of detectors, so the corresponding measurers and the necessary tools. Detectors cleaning; there is an anaerobic chamber for the detectors handling at inert atmosphere, a smoke extraction bell for cleaning with the detector solvents. Cryogenic; there are vessels and tools for handling liquid nitrogen which is used for cooling the detectors when they required it. (Author)

  7. Incorporating single detector failure into the ROP detector layout optimization for CANDU reactors

    Energy Technology Data Exchange (ETDEWEB)

    Kastanya, Doddy, E-mail: Doddy.Kastanya@snclavalin.com

    2015-12-15

    Highlights: • ROP TSP value needs to be adjusted when any detector in the system fails. • Single detector failure criterion has been incorporated into the detector layout optimization as a constraint. • Results show that the optimized detector layout is more robust with respect to its vulnerability to a single detector failure. • An early rejection scheme has been introduced to speed-up the optimization process. - Abstract: In CANDU{sup ®} reactors, the regional overpower protection (ROP) systems are designed to protect the reactor against overpower in the fuel which could reduce the safety margin-to-dryout. In the CANDU{sup ®} 600 MW (CANDU 6) design, there are two ROP systems in the core, each of which is connected to a fast-acting shutdown system. Each ROP system consists of a number of fast-responding, self-powered flux detectors suitably distributed throughout the core within vertical and horizontal flux detector assemblies. The placement of these ROP detectors is a challenging discrete optimization problem. In the past few years, two algorithms, DETPLASA and ADORE, have been developed to optimize the detector layout for the ROP systems in CANDU reactors. These algorithms utilize the simulated annealing (SA) technique to optimize the placement of the detectors in the core. The objective of the optimization process is typically either to maximize the TSP value for a given number of detectors in the system or to minimize the number of detectors in the system to obtain a target TSP value. One measure to determine the robustness of the optimized detector layout is to evaluate the maximum decrease (penalty) in TSP value when any single detector in the system fails. The smaller the penalty, the more robust the design is. Therefore, in order to ensure that the optimized detector layout is robust, the single detector failure (SDF) criterion has been incorporated as an additional constraint into the ADORE algorithm. Results from this study indicate that there

  8. Funny Numbers

    Directory of Open Access Journals (Sweden)

    Theodore M. Porter

    2012-12-01

    Full Text Available The struggle over cure rate measures in nineteenth-century asylums provides an exemplary instance of how, when used for official assessments of institutions, these numbers become sites of contestation. The evasion of goals and corruption of measures tends to make these numbers “funny” in the sense of becoming dis-honest, while the mismatch between boring, technical appearances and cunning backstage manipulations supplies dark humor. The dangers are evident in recent efforts to decentralize the functions of governments and corporations using incen-tives based on quantified targets.

  9. Transcendental numbers

    CERN Document Server

    Murty, M Ram

    2014-01-01

    This book provides an introduction to the topic of transcendental numbers for upper-level undergraduate and graduate students. The text is constructed to support a full course on the subject, including descriptions of both relevant theorems and their applications. While the first part of the book focuses on introducing key concepts, the second part presents more complex material, including applications of Baker’s theorem, Schanuel’s conjecture, and Schneider’s theorem. These later chapters may be of interest to researchers interested in examining the relationship between transcendence and L-functions. Readers of this text should possess basic knowledge of complex analysis and elementary algebraic number theory.

  10. Spectral response of multi-element silicon detectors

    Energy Technology Data Exchange (ETDEWEB)

    Ludewigt, B.A.; Rossington, C.S.; Chapman, K. [Univ. of California, Berkeley, CA (United States)

    1997-04-01

    Multi-element silicon strip detectors, in conjunction with integrated circuit pulse-processing electronics, offer an attractive alternative to conventional lithium-drifted silicon Si(Li) and high purity germanium detectors (HPGe) for high count rate, low noise synchrotron x-ray fluorescence applications. One of the major differences between the segmented Si detectors and the commercially available single-element Si(Li) or HPGe detectors is that hundreds of elements can be fabricated on a single Si substrate using standard silicon processing technologies. The segmentation of the detector substrate into many small elements results in very low noise performance at or near, room temperature, and the count rate of the detector is increased many-fold due to the multiplication in the total number of detectors. Traditionally, a single channel of detector with electronics can handle {approximately}100 kHz count rates while maintaining good energy resolution; the segmented detectors can operate at greater than MHz count rates merely due to the multiplication in the number of channels. One of the most critical aspects in the development of the segmented detectors is characterizing the charge sharing and charge loss that occur between the individual detector strips, and determining how these affect the spectral response of the detectors.

  11. Photon-number correlation for quantum enhanced imaging and sensing

    Science.gov (United States)

    Meda, A.; Losero, E.; Samantaray, N.; Scafirimuto, F.; Pradyumna, S.; Avella, A.; Ruo-Berchera, I.; Genovese, M.

    2017-09-01

    In this review we present the potentialities and the achievements of the use of non-classical photon-number correlations in twin-beam states for many applications, ranging from imaging to metrology. Photon-number correlations in the quantum regime are easily produced and are rather robust against unavoidable experimental losses, and noise in some cases, if compared to the entanglement, where losing one photon can completely compromise the state and its exploitable advantages. Here, we will focus on quantum enhanced protocols in which only phase-insensitive intensity measurements (photon-number counting) are performed, which allow probing the transmission/absorption properties of a system, leading, for example, to innovative target detection schemes in a strong background. In this framework, one of the advantages is that the sources experimentally available emit a wide number of pair-wise correlated modes, which can be intercepted and exploited separately, for example by many pixels of a camera, providing a parallelism, essential in several applications, such as wide-field sub-shot-noise imaging and quantum enhanced ghost imaging. Finally, non-classical correlation enables new possibilities in quantum radiometry, e.g. the possibility of absolute calibration of a spatial resolving detector from the on-off single-photon regime to the linear regime in the same setup.

  12. Development of a novel depth of interaction PET detector using highly multiplexed G-APD cross-strip encoding

    Energy Technology Data Exchange (ETDEWEB)

    Kolb, A., E-mail: armin.kolb@med.uni-tuebingen.de; Parl, C.; Liu, C. C.; Pichler, B. J. [Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, Eberhard Karls University, 72076 Tübingen (Germany); Mantlik, F. [Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, Eberhard Karls University, 72076 Tübingen, Germany and Department of Empirical Inference, Max Planck Institute for Intelligent Systems, 72076 Tübingen (Germany); Lorenz, E. [Max Planck Institute for Physics, Föhringer Ring 6, 80805 München (Germany); Renker, D. [Department of Physics, Technische Universität München, 85748 Garching (Germany)

    2014-08-15

    Purpose: The aim of this study was to develop a prototype PET detector module for a combined small animal positron emission tomography and magnetic resonance imaging (PET/MRI) system. The most important factor for small animal imaging applications is the detection sensitivity of the PET camera, which can be optimized by utilizing longer scintillation crystals. At the same time, small animal PET systems must yield a high spatial resolution. The measured object is very close to the PET detector because the bore diameter of a high field animal MR scanner is limited. When used in combination with long scintillation crystals, these small-bore PET systems generate parallax errors that ultimately lead to a decreased spatial resolution. Thus, we developed a depth of interaction (DoI) encoding PET detector module that has a uniform spatial resolution across the whole field of view (FOV), high detection sensitivity, compactness, and insensitivity to magnetic fields. Methods: The approach was based on Geiger mode avalanche photodiode (G-APD) detectors with cross-strip encoding. The number of readout channels was reduced by a factor of 36 for the chosen block elements. Two 12 × 2 G-APD strip arrays (25μm cells) were placed perpendicular on each face of a 12 × 12 lutetium oxyorthosilicate crystal block with a crystal size of 1.55 × 1.55 × 20 mm. The strip arrays were multiplexed into two channels and used to calculate the x, y coordinates for each array and the deposited energy. The DoI was measured in step sizes of 1.8 mm by a collimated {sup 18}F source. The coincident resolved time (CRT) was analyzed at all DoI positions by acquiring the waveform for each event and applying a digital leading edge discriminator. Results: All 144 crystals were well resolved in the crystal flood map. The average full width half maximum (FWHM) energy resolution of the detector was 12.8% ± 1.5% with a FWHM CRT of 1.14 ± 0.02 ns. The average FWHM DoI resolution over 12 crystals was 2.90

  13. Semiconductor detectors with proximity signal readout

    International Nuclear Information System (INIS)

    Asztalos, Stephen J.

    2012-01-01

    Semiconductor-based radiation detectors are routinely used for the detection, imaging, and spectroscopy of x-rays, gamma rays, and charged particles for applications in the areas of nuclear and medical physics, astrophysics, environmental remediation, nuclear nonproliferation, and homeland security. Detectors used for imaging and particle tracking are more complex in that they typically must also measure the location of the radiation interaction in addition to the deposited energy. In such detectors, the position measurement is often achieved by dividing or segmenting the electrodes into many strips or pixels and then reading out the signals from all of the electrode segments. Fine electrode segmentation is problematic for many of the standard semiconductor detector technologies. Clearly there is a need for a semiconductor-based radiation detector technology that can achieve fine position resolution while maintaining the excellent energy resolution intrinsic to semiconductor detectors, can be fabricated through simple processes, does not require complex electrical interconnections to the detector, and can reduce the number of required channels of readout electronics. Proximity electrode signal readout (PESR), in which the electrodes are not in physical contact with the detector surface, satisfies this need

  14. New flux detectors for CANDU 6 reactors

    International Nuclear Information System (INIS)

    Cuttler, J.M.; Medak, N.

    1992-06-01

    CANDU reactors utilize large numbers of in-core self-powered detectors for control and protection. In the original design, the detectors (coaxial cables) were wound on carrier tubes and immersed in the heavy water moderator. Failures occurred due to corrosion and other factors, and replacement was very costly because the assemblies were not designed with maintenance in mind. A new design was conceived based on straight detectors, of larger diameter, in a sealed package of individual 'well' tubes. This protected the detectors from hostile environments and enabled individual failed sensors to be replaced by inserting spares in vacant neighbouring tubes. The new design was made retrofittable to older CANDU reactors. Provision was made for on-line scanning of the core with a miniature fission chamber. The modified detectors were tested in a lengthy development program and found to exhibit superior performance to that of the original detectors. Most of the CANDU reactors have now adopted the new design. In the case of the Gentilly-2 and Point Lepreau reactors, advantage was taken of the opportunity to redesign the detector layout (using better codes and the increased flexibility in positioning detectors) to achieve better coverage of abnormal events, leading to higher trip setpoints and wider operating margins

  15. Transfinite Numbers

    Indian Academy of Sciences (India)

    this is a characteristic difference between finite and infinite sets and created an immensely useful branch of mathematics based on this idea which had a great impact on the whole of mathe- matics. For example, the question of what is a number (finite or infinite) is almost a philosophical one. However Cantor's work turned it ...

  16. Locating gamma radiation source by self collimating BGO detector system

    Energy Technology Data Exchange (ETDEWEB)

    Orion, I; Pernick, A; Ilzycer, D; Zafrir, H [Israel Atomic Energy Commission, Yavne (Israel). Soreq Nuclear Research Center; Shani, G [Ben-Gurion Univ. of the Negev, Beersheba (Israel)

    1996-12-01

    The need for airborne collimated gamma detector system to estimate the radiation released from a nuclear accident has been established. A BGO detector system has been developed as an array of separate seven cylindrical Bismuth Germanate scintillators, one central detector symmetrically surrounded by six detectors. In such an arrangement, each of the detectors reduced the exposure of other detectors in the array to a radiation incident from a possible specific spatial angle, around file array. This shielding property defined as `self-collimation`, differs the point source response function for each of the detectors. The BGO detector system has a high density and atomic number, and therefore provides efficient self-collimation. Using the response functions of the separate detectors enables locating point sources as well as the direction of a nuclear radioactive plume with satisfactory angular resolution, of about 10 degrees. The detector`s point source response, as function of the source direction, in a horizontal plane, has been predicted by analytical calculation, and was verified by Monte-Carlo simulation using the code EGS4. The detector`s response was tested in a laboratory-scale experiment for several gamma ray energies, and the experimental results validated the theoretical (analytical and Monte-Carlo) results. (authors).

  17. Multiple detectors “Influence Method”

    International Nuclear Information System (INIS)

    Rios, I.J.; Mayer, R.E.

    2016-01-01

    The “Influence Method” is conceived for the absolute determination of a nuclear particle flux in the absence of known detector efficiency and without the need to register coincidences of any kind. This method exploits the influence of the presence of one detector in the count rate of another detector, when they are placed one behind the other and define statistical estimators for the absolute number of incident particles and for the efficiency (Rios and Mayer, 2015a). Its detailed mathematical description was recently published (Rios and Mayer, 2015b) and its practical implementation in the measurement of a moderated neutron flux arising from an isotopic neutron source was exemplified in (Rios and Mayer, 2016). With the objective of further reducing the measurement uncertainties, in this article we extend the method for the case of multiple detectors placed one behind the other. The new estimators for the number of particles and the detection efficiency are herein derived. - Highlights: • “Multiple Detector Influence Method” developed for uncertainty reduction. • Absolute particle counting in absence of known detector efficiency. • Detector set efficiency determination.

  18. Laser and beta source setup characterization of 3D-DDTC detectors fabricated at FBK-irst

    Energy Technology Data Exchange (ETDEWEB)

    Zoboli, A. [INFN, Sezione di Padova (Gruppo Collegato di Trento), and Dipartimento di Ingegneria e Scienza dell' Informazione, Universita di Trento, Via Sommarive, 14, I-38050 Povo (Trento) (Italy)], E-mail: zoboli@disi.unitn.it; Dalla Betta, G.-F. [INFN, Sezione di Padova (Gruppo Collegato di Trento), and Dipartimento di Ingegneria e Scienza dell' Informazione, Universita di Trento, Via Sommarive, 14, I-38050 Povo (Trento) (Italy); Boscardin, M. [Fondazione Bruno Kessler, Centro per i Materiali e i Microsistemi, Via Sommarive, 18, I-38050 Povo (Trento) (Italy); Bosisio, L. [Dip. di Fisica e INFN, Universita di Trieste, I-34127, Trieste (Italy); Eckert, S.; Kuehn, S.; Parzefall, U. [Institute of Physics, University of Freiburg, Hermann-Herder-Str. 3, 79104 Freiburg (Germany); Piemonte, C.; Ronchin, S.; Zorzi, N. [Fondazione Bruno Kessler, Centro per i Materiali e i Microsistemi, Via Sommarive, 18, I-38050 Povo (Trento) (Italy)

    2009-06-01

    We report on the functional characterization of the first batch of 3D Double-Sided Double Type Column (3D-DDTC) detectors fabricated at FBK, Trento. This detector concept represents the evolution of the previous 3D-STC detectors towards full 3D detectors, and is expected to achieve a performance which is comparable to standard 3D detectors, but with a simpler fabrication process. Measurements were performed on detectors in the microstrip configuration coupled to the ATLAS ABCD3T binary readout. This paper reports spatially resolved signal efficiency tests made with a pulsed infrared laser setup and charge collection efficiency tests made with a Beta source.

  19. Laser and beta source setup characterization of 3D-DDTC detectors fabricated at FBK-irst

    International Nuclear Information System (INIS)

    Zoboli, A.; Dalla Betta, G.-F.; Boscardin, M.; Bosisio, L.; Eckert, S.; Kuehn, S.; Parzefall, U.; Piemonte, C.; Ronchin, S.; Zorzi, N.

    2009-01-01

    We report on the functional characterization of the first batch of 3D Double-Sided Double Type Column (3D-DDTC) detectors fabricated at FBK, Trento. This detector concept represents the evolution of the previous 3D-STC detectors towards full 3D detectors, and is expected to achieve a performance which is comparable to standard 3D detectors, but with a simpler fabrication process. Measurements were performed on detectors in the microstrip configuration coupled to the ATLAS ABCD3T binary readout. This paper reports spatially resolved signal efficiency tests made with a pulsed infrared laser setup and charge collection efficiency tests made with a Beta source.

  20. Data handling for the ''big lepton'' detector

    International Nuclear Information System (INIS)

    Cutts, D.

    1977-01-01

    The large lepton detector proposed and described in previous workshops was used as a known standard to study how data might be gathered, sorted, and recorded for ISABELLE detectors. The main source of concern is the high singles rate throughout most of the detector, together with the enormous number of individual devices that are running at this rate and must be serviced for each event. A calculation is given of this rate; the result is 1.0 x 10 7 particles/sec into the detector (at 10 32 /cm 2 sec). In this particular situation the use of charge coupled devices is natural; individual data elements feed continuously into these ''analog delay lines''; yet the data relevant to an occasional event are processed in parallel through a limited number of channels. The general technique seems desirable for many large scale experiments which manage to achieve in some way a reasonable trigger rate

  1. Applying Statistical Mechanics to pixel detectors

    International Nuclear Information System (INIS)

    Pindo, Massimiliano

    2002-01-01

    Pixel detectors, being made of a large number of active cells of the same kind, can be considered as significant sets to which Statistical Mechanics variables and methods can be applied. By properly redefining well known statistical parameters in order to let them match the ones that actually characterize pixel detectors, an analysis of the way they work can be performed in a totally new perspective. A deeper understanding of pixel detectors is attained, helping in the evaluation and comparison of their intrinsic characteristics and performance

  2. Time-Resolved Hard X-Ray Spectrometer

    International Nuclear Information System (INIS)

    Kenneth Moya; Ian McKennaa; Thomas Keenana; Michael Cuneob

    2007-01-01

    Wired array studies are being conducted at the SNL Z accelerator to maximize the x-ray generation for inertial confinement fusion targets and high energy density physics experiments. An integral component of these studies is the characterization of the time-resolved spectral content of the x-rays. Due to potential spatial anisotropy in the emitted radiation, it is also critical to diagnose the time-evolved spectral content in a space-resolved manner. To accomplish these two measurement goals, we developed an x-ray spectrometer using a set of high-speed detectors (silicon PIN diodes) with a collimated field-of-view that converged on a 1-cm-diameter spot at the pinch axis. Spectral discrimination is achieved by placing high Z absorbers in front of these detectors. We built two spectrometers to permit simultaneous different angular views of the emitted radiation. Spectral data have been acquired from recent Z shots for the radial and polar views. UNSPEC1 has been adapted to analyze and unfold the measured data to reconstruct the x-ray spectrum. The unfold operator code, UFO2, is being adapted for a more comprehensive spectral unfolding treatment

  3. Physics of multiple muons in underground detectors

    International Nuclear Information System (INIS)

    Gaisser, T.K.; Stanev, T.

    1982-01-01

    We summarize results of Monte Carlo simulations of underground muons with a set of parametrizations for number and lateral distribution of muons at various detector depths. We also describe the size distributions of accompanying showers at the surface. We give some illustrations of the use of these results to study the surface-underground correlation and to interpret preliminary results of the Soudan-I detector presented at this conference

  4. Nuclear radiation detectors

    International Nuclear Information System (INIS)

    Kapoor, S.S.; Ramamurthy, V.S.

    1986-01-01

    The present monograph is intended to treat the commonly used detectors in the field of nuclear physics covering important developments of the recent years. After a general introduction, a brief account of interaction of radiation with matter relevant to the processes in radiation detection is given in Chapter II. In addition to the ionization chamber, proportional counters and Geiger Mueller counters, several gas-filled detectors of advanced design such as those recently developed for heavy ion physics and other types of studies have been covered in Chapter III. Semiconductor detectors are dealt with in Chapter IV. The scintillation detectors which function by sensing the photons emitted by the luminescence process during the interaction of the impinging radiation with the scintillation detector medium are described in Chapter V. The topic of neutron detectors is covered in Chapter VI, as in this case the emphasis is more on the method of neutron detection rather than on detector type. Electronic instrumentation related to signal pulse processing dealt with in Chapter VII. The track etch detectors based on the visualization of the track of the impinging charge particle have also been briefly covered in the last chapter. The scope of this monograph is confined to detectors commonly used in low and medium energy nuclear physics research and applications of nuclear techniques. The monograph is intended for post-graduate students and those beginning to work with the radiation detectors. (author)

  5. Charge transport properties of CdMnTe radiation detectors

    Energy Technology Data Exchange (ETDEWEB)

    Kim K.; Rafiel, R.; Boardman, M.; Reinhard, I.; Sarbutt, A.; Watt, G.; Watt, C.; Uxa, S.; Prokopovich, D.A.; Belas, E.; Bolotnikov, A.E.; James, R.B.

    2012-04-11

    Growth, fabrication and characterization of indium-doped cadmium manganese telluride (CdMnTe)radiation detectors have been described. Alpha-particle spectroscopy measurements and time resolved current transient measurements have yielded an average charge collection efficiency approaching 100 %. Spatially resolved charge collection efficiency maps have been produced for a range of detector bias voltages. Inhomogeneities in the charge transport of the CdMnTe crystals have been associated with chains of tellurium inclusions within the detector bulk. Further, it has been shown that the role of tellurium inclusions in degrading chargecollection is reduced with increasing values of bias voltage. The electron transit time was determined from time of flight measurements. From the dependence of drift velocity on applied electric field the electron mobility was found to be n = (718 55) cm2/Vs at room temperature.

  6. Charge transport properties of CdMnTe radiation detectors

    Directory of Open Access Journals (Sweden)

    Prokopovich D. A.

    2012-10-01

    Full Text Available Growth, fabrication and characterization of indium-doped cadmium manganese telluride (CdMnTe radiation detectors have been described. Alpha-particle spectroscopy measurements and time resolved current transient measurements have yielded an average charge collection efficiency approaching 100 %. Spatially resolved charge collection efficiency maps have been produced for a range of detector bias voltages. Inhomogeneities in the charge transport of the CdMnTe crystals have been associated with chains of tellurium inclusions within the detector bulk. Further, it has been shown that the role of tellurium inclusions in degrading charge collection is reduced with increasing values of bias voltage. The electron drift velocity was calculated from the rise time distribution of the preamplifier output pulses at each measured bias. From the dependence of drift velocity on applied electric field the electron mobility was found to be μn = (718 ± 55 cm2/Vs at room temperature.

  7. Resolving a protracted refugee situation through a regional process

    Directory of Open Access Journals (Sweden)

    Olga Mitrovic

    2015-09-01

    Full Text Available Protracted refugee situations are usually a result of political deadlock, and their resolution demands the involvement of a range of actors and a multifaceted approach focused on leveraging political will. Despite its shortcomings, the Regional Process in the Western Balkans offers a number of lessons for resolving such situations.

  8. Enforcement actions: Significant actions resolved

    International Nuclear Information System (INIS)

    1993-09-01

    This compilation summarizes significant enforcement actions that have been resolved during one quarterly period (April--June 1993) and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to licensees with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication

  9. Mediation for resolving family disputes

    Directory of Open Access Journals (Sweden)

    Kamenecka-Usova M.

    2016-01-01

    Full Text Available Nowadays the understanding of the institute of marriage and its importance in the society has changed. Marriage is no longer assumed to be a commitment for a lifetime. As the principle of equality has replaced hierarchy as the guiding principle of family law it gave more grounds for family disputes and it became socially acceptable to leave marriages that are intolerable or merely unfulfilling. The aim of this article is to suggest an alternative dispute resolution method-mediation as a worthy option for resolving family conflicts.

  10. Enforcement actions: Significant actions resolved

    International Nuclear Information System (INIS)

    1991-05-01

    This compilation summarizes significant enforcement actions that have been resolved during one quarterly period (January--March 1991) and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to licensees with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication

  11. Enforcement actions: Significant actions resolved

    International Nuclear Information System (INIS)

    1991-02-01

    This compilation summarizes significant enforcement actions that have been resolved during one quarterly period (October--December 1990) and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to licensees with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication

  12. Enforcement actions: Significant actions resolved

    International Nuclear Information System (INIS)

    1990-03-01

    This compilation summarizes significant enforcement actions that have been resolved during one quarterly period (October--December 1989) and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to licensees with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication

  13. Enforcement actions: Significant actions resolved

    International Nuclear Information System (INIS)

    1990-11-01

    This compilation summarizes significant enforcement actions that have been resolved during one quarterly period (July--September 1990) and includes copies of letters, notices, and orders sent by the Nuclear Regulatory Commission to licensees with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication

  14. Enforcement actions: Significant actions resolved

    International Nuclear Information System (INIS)

    1992-08-01

    This compilation summarizes significant enforcement actions that have been resolved during one quarterly period (April--June 1992) and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to licensees with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication

  15. Enforcement actions: Significant actions resolved

    International Nuclear Information System (INIS)

    1990-09-01

    This compilation summarizes significant enforcement actions that have been resolved during one quarterly period (April--June 1990) and includes copies of letters, notices, and orders sent by the Nuclear Regulatory Commission to licensees with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication

  16. Enforcement actions: Significant actions resolved

    International Nuclear Information System (INIS)

    1993-06-01

    This compilation summarizes significant enforcement actions that have been resolved during one quarterly period (January--March 1993) and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to licensees with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication

  17. Enforcement actions: Significant actions resolved

    International Nuclear Information System (INIS)

    1992-05-01

    This compilation summarizes significant enforcement actions that have been resolved during one quarterly period (January--March 1992) and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to licensees with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication

  18. Enforcement actions: Significant actions resolved

    International Nuclear Information System (INIS)

    1993-12-01

    This compilation summarizes significant enforcement actions that have been resolved during one quarterly period (July--September 1993) and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to licensees with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication

  19. Enforcement actions: Significant actions resolved

    International Nuclear Information System (INIS)

    1993-03-01

    This compilation summarizes significant enforcement actions that have been resolved during one quarterly period (October--December 1992) and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to licensees with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication

  20. Enforcement actions: Significant actions resolved

    International Nuclear Information System (INIS)

    1991-07-01

    This compilation summarizes significant enforcement actions that have been resolved during one quarterly period (April-June 1991) and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to licensees with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication

  1. Enforcement actions: Significant actions resolved

    International Nuclear Information System (INIS)

    1991-11-01

    This compilation summarizes significant enforcement actions that have been resolved during one quarterly period (July--September 1991) and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to licensees with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication

  2. Enforcement actions: Significant actions resolved

    International Nuclear Information System (INIS)

    1992-03-01

    This compilation summarizes significant enforcement actions that have been resolved during one quarterly period (October--December 1991) and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to licensees with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication

  3. Enforcement actions: Significant actions resolved

    International Nuclear Information System (INIS)

    1989-12-01

    This compilation summarizes significant enforcement actions that have been resolved during one quarterly period (July--September 1989) and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to licensees with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication

  4. 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

  5. Detectors for Particle Radiation

    Science.gov (United States)

    Kleinknecht, Konrad

    1999-01-01

    This textbook provides a clear, concise and comprehensive review of the physical principles behind the devices used to detect charged particles and gamma rays, and the construction and performance of these many different types of detectors. Detectors for high-energy particles and radiation are used in many areas of science, especially particle physics and nuclear physics experiments, nuclear medicine, cosmic ray measurements, space sciences and geological exploration. This second edition includes all the latest developments in detector technology, including several new chapters covering micro-strip gas chambers, silicion strip detectors and CCDs, scintillating fibers, shower detectors using noble liquid gases, and compensating calorimeters for hadronic showers. This well-illustrated textbook contains examples from the many areas in science in which these detectors are used. It provides both a coursebook for students in physics, and a useful introduction for researchers in other fields.

  6. Silicon Telescope Detectors

    CERN Document Server

    Gurov, Yu B; Sandukovsky, V G; Yurkovski, J

    2005-01-01

    The results of research and development of special silicon detectors with a large active area ($> 8 cm^{2}$) for multilayer telescope spectrometers (fulfilled in the Laboratory of Nuclear Problems, JINR) are reviewed. The detector parameters are listed. The production of totally depleted surface barrier detectors (identifiers) operating under bias voltage two to three times higher than depletion voltage is described. The possibility of fabrication of lithium drifted counters with a very thin entrance window on the diffusion side of the detector (about 10--20 $\\mu$m) is shown. The detector fabrication technique has allowed minimizing detector dead regions without degradation of their spectroscopic characteristics and reliability during long time operation in charge particle beams.

  7. Physics of scintillation detectors

    International Nuclear Information System (INIS)

    Novotny, R.

    1991-01-01

    The general concept of a radiation detector is based on three fundamental principles: sensitivity of the device to the radiation of interest which requires a large cross-section in the detector material, detector response function to the physical properties of the radiation. As an example, a scintillation detector for charged particles should allow to identify the charge of the particle, its kinetic energy and the time of impact combined with optimum resolutions. Optimum conversion of the detector response (like luminescence of a scintillator) into electronical signals for further processing. The following article will concentrate on the various aspects of the first two listed principles as far as they appear to be relevant for photon and charged particle detection using organic and inorganic scintillation detectors. (orig.)

  8. History of infrared detectors

    Science.gov (United States)

    Rogalski, A.

    2012-09-01

    This paper overviews the history of infrared detector materials starting with Herschel's experiment with thermometer on February 11th, 1800. Infrared detectors are in general used to detect, image, and measure patterns of the thermal heat radiation which all objects emit. At the beginning, their development was connected with thermal detectors, such as thermocouples and bolometers, which are still used today and which are generally sensitive to all infrared wavelengths and operate at room temperature. The second kind of detectors, called the photon detectors, was mainly developed during the 20th Century to improve sensitivity and response time. These detectors have been extensively developed since the 1940's. Lead sulphide (PbS) was the first practical IR detector with sensitivity to infrared wavelengths up to ˜3 μm. After World War II infrared detector technology development was and continues to be primarily driven by military applications. Discovery of variable band gap HgCdTe ternary alloy by Lawson and co-workers in 1959 opened a new area in IR detector technology and has provided an unprecedented degree of freedom in infrared detector design. Many of these advances were transferred to IR astronomy from Departments of Defence research. Later on civilian applications of infrared technology are frequently called "dual-use technology applications." One should point out the growing utilisation of IR technologies in the civilian sphere based on the use of new materials and technologies, as well as the noticeable price decrease in these high cost technologies. In the last four decades different types of detectors are combined with electronic readouts to make detector focal plane arrays (FPAs). Development in FPA technology has revolutionized infrared imaging. Progress in integrated circuit design and fabrication techniques has resulted in continued rapid growth in the size and performance of these solid state arrays.

  9. The atlas detector

    International Nuclear Information System (INIS)

    Perrodo, P.

    2001-01-01

    The ATLAS detector, one of the two multi-purpose detectors at the Large Hadron Collider at CERN, is currently being built in order to meet the first proton-proton collisions in time. A description of the detector components will be given, corresponding to the most up to date design and status of construction, completed with test beam results and performances of the first serial modules. (author)

  10. Cherenkov water detector NEVOD

    Science.gov (United States)

    Petrukhin, A. A.

    2015-05-01

    A unique multipurpose Cherenkov water detector, the NEVOD facility, uses quasispherical measuring modules to explore all the basic components of cosmic rays on Earth's surface, including neutrinos. Currently, the experimental complex includes the Cherenkov water detector, a calibration telescope system, and a coordinate detector. This paper traces the basic development stages of NEVOD, examines research directions, presents the results obtained, including the search for the solution to the 'muon puzzle', and discusses possible future development prospects.

  11. Noble Gas Detectors

    CERN Document Server

    Aprile, Elena; Bolozdynya, Alexander I; Doke, Tadayoshi

    2006-01-01

    This book discusses the physical properties of noble fluids, operational principles of detectors based on these media, and the best technical solutions to the design of these detectors. Essential attention is given to detector technology: purification methods and monitoring of purity, information readout methods, electronics, detection of hard ultra-violet light emission, selection of materials, cryogenics etc.The book is mostly addressed to physicists and graduate students involved in the preparation of fundamental next generation experiments, nuclear engineers developing instrumentation

  12. Study on Silicon detectors

    International Nuclear Information System (INIS)

    Gervino, G.; Boero, M.; Manfredotti, C.; Icardi, M.; Gabutti, A.; Bagnolatti, E.; Monticone, E.

    1990-01-01

    Prototypes of Silicon microstrip detectors and Silicon large area detectors (3x2 cm 2 ), realized directly by our group, either by ion implantation or by diffusion are presented. The physical detector characteristics and their performances determined by exposing them to different radioactive sources and the results of extensive tests on passivation, where new technological ways have been investigated, are discussed. The calculation of the different terms contributing to the total dark current is reported

  13. The solenoidal detector collaboration silicon detector system

    International Nuclear Information System (INIS)

    Ziock, H.J.; Gamble, M.T.; Miller, W.O.; Palounek, A.P.T.; Thompson, T.C.

    1992-01-01

    Silicon tracking systems (STS) will be fundamental components of the tracking systems for both planned major SSC experiments. The STS is physically a small part of the central tracking system and the calorimeter of the detector being proposed by the Solenoidal Detector Collaboration (SDC). Despite its seemingly small size, it occupies a volume of more than 5 meters in length and 1 meter in diameter and is an order of magnitude larger than any silicon detector system previously built. The STS will consist of silicon microstrip detectors and possibly silicon pixel detectors. The other two components are an outer barrel tracker, which will consist of straw tubes or scintillating fibers; and an outer intermediate angle tracker, which will consist of gas microstrips. The components are designed to work as an integrated system. Each componenet has specific strengths, but is individually incapable of providing the overall performance required by the physics goals of the SSC. The large particle fluxes, the short times between beam crossing, the high channel count, and the required very high position measurement accuracy pose challenging problems that must be solved. Furthermore, to avoid degrading the measurements, the solutions must be achieved using only a minimal amount of material. An additional constraint is that only low-Z materials are allowed. If that were not difficlut enough, the solutions must also be affordable

  14. LHCb Detector Performance

    CERN Document Server

    Aaij, Roel; Adinolfi, Marco; Affolder, Anthony; Ajaltouni, Ziad; Akar, Simon; Albrecht, Johannes; Alessio, Federico; Alexander, Michael; Ali, Suvayu; Alkhazov, Georgy; Alvarez Cartelle, Paula; Alves Jr, Antonio Augusto; Amato, Sandra; Amerio, Silvia; Amhis, Yasmine; An, Liupan; Anderlini, Lucio; Anderson, Jonathan; Andreassen, Rolf; Andreotti, Mirco; Andrews, Jason; Appleby, Robert; Aquines Gutierrez, Osvaldo; Archilli, Flavio; Artamonov, Alexander; Artuso, Marina; Aslanides, Elie; Auriemma, Giulio; Baalouch, Marouen; Bachmann, Sebastian; Back, John; Badalov, Alexey; Baesso, Clarissa; Baldini, Wander; Barlow, Roger; Barschel, Colin; Barsuk, Sergey; Barter, William; Batozskaya, Varvara; Battista, Vincenzo; Bay, Aurelio; Beaucourt, Leo; Beddow, John; Bedeschi, Franco; Bediaga, Ignacio; Belogurov, Sergey; Belous, Konstantin; Belyaev, Ivan; Ben-Haim, Eli; Bencivenni, Giovanni; Benson, Sean; Benton, Jack; Berezhnoy, Alexander; Bernet, Roland; Bettler, Marc-Olivier; van Beuzekom, Martinus; Bien, Alexander; Bifani, Simone; Bird, Thomas; Bizzeti, Andrea; Bjørnstad, Pål Marius; Blake, Thomas; Blanc, Frédéric; Blouw, Johan; Blusk, Steven; Bocci, Valerio; Bondar, Alexander; Bondar, Nikolay; Bonivento, Walter; Borghi, Silvia; Borgia, Alessandra; Borsato, Martino; Bowcock, Themistocles; Bowen, Espen Eie; Bozzi, Concezio; Brambach, Tobias; Bressieux, Joël; Brett, David; Britsch, Markward; Britton, Thomas; Brodzicka, Jolanta; Brook, Nicholas; Brown, Henry; Bursche, Albert; Buytaert, Jan; Cadeddu, Sandro; Calabrese, Roberto; Calvi, Marta; Calvo Gomez, Miriam; Campana, Pierluigi; Campora Perez, Daniel; Carbone, Angelo; Carboni, Giovanni; Cardinale, Roberta; Cardini, Alessandro; Carson, Laurence; Carvalho Akiba, Kazuyoshi; Casse, Gianluigi; Cassina, Lorenzo; Castillo Garcia, Lucia; Cattaneo, Marco; Cauet, Christophe; Cenci, Riccardo; Charles, Matthew; Charpentier, Philippe; Chefdeville, Maximilien; Chen, Shanzhen; Cheung, Shu-Faye; Chiapolini, Nicola; Chrzaszcz, Marcin; Ciba, Krzystof; Cid Vidal, Xabier; Ciezarek, Gregory; Clarke, Peter; Clemencic, Marco; Cliff, Harry; Closier, Joel; Coco, Victor; Cogan, Julien; Cogneras, Eric; Cogoni, Violetta; Cojocariu, Lucian; Collazuol, Gianmaria; Collins, Paula; Comerma-Montells, Albert; Contu, Andrea; Cook, Andrew; Coombes, Matthew; Coquereau, Samuel; Corti, Gloria; Corvo, Marco; Counts, Ian; Couturier, Benjamin; Cowan, Greig; Craik, Daniel Charles; Crocombe, Andrew; Cruz Torres, Melissa Maria; Cunliffe, Samuel; Currie, Robert; D'Ambrosio, Carmelo; Dalseno, Jeremy; David, Pascal; David, Pieter; Davis, Adam; De Bruyn, Kristof; De Capua, Stefano; De Cian, Michel; De Miranda, Jussara; De Paula, Leandro; De Silva, Weeraddana; De Simone, Patrizia; Decamp, Daniel; Deckenhoff, Mirko; Del Buono, Luigi; Déléage, Nicolas; Derkach, Denis; Deschamps, Olivier; Dettori, Francesco; Di Canto, Angelo; Dijkstra, Hans; Donleavy, Stephanie; Dordei, Francesca; Dorigo, Mirco; Dosil Suárez, Alvaro; Dossett, David; Dovbnya, Anatoliy; Dreimanis, Karlis; Dujany, Giulio; Dupertuis, Frederic; Durante, Paolo; Dzhelyadin, Rustem; Dziurda, Agnieszka; Dzyuba, Alexey; Easo, Sajan; Egede, Ulrik; Egorychev, Victor; Eidelman, Semen; Eisenhardt, Stephan; Eitschberger, Ulrich; Ekelhof, Robert; Eklund, Lars; El Rifai, Ibrahim; Elsasser, Christian; Ely, Scott; Esen, Sevda; Evans, Hannah Mary; Evans, Timothy; Falabella, Antonio; Färber, Christian; Farinelli, Chiara; Farley, Nathanael; Farry, Stephen; Fay, Robert; Ferguson, Dianne; Fernandez Albor, Victor; Ferreira Rodrigues, Fernando; Ferro-Luzzi, Massimiliano; Filippov, Sergey; Fiore, Marco; Fiorini, Massimiliano; Firlej, Miroslaw; Fitzpatrick, Conor; Fiutowski, Tomasz; Fol, Philip; Fontana, Marianna; Fontanelli, Flavio; Forty, Roger; Francisco, Oscar; Frank, Markus; Frei, Christoph; Frosini, Maddalena; Fu, Jinlin; Furfaro, Emiliano; Gallas Torreira, Abraham; Galli, Domenico; Gallorini, Stefano; Gambetta, Silvia; Gandelman, Miriam; Gandini, Paolo; Gao, Yuanning; García Pardiñas, Julián; Garofoli, Justin; Garra Tico, Jordi; Garrido, Lluis; Gascon, David; Gaspar, Clara; Gauld, Rhorry; Gavardi, Laura; Geraci, Angelo; Gersabeck, Evelina; Gersabeck, Marco; Gershon, Timothy; Ghez, Philippe; Gianelle, Alessio; Gianì, Sebastiana; Gibson, Valerie; Giubega, Lavinia-Helena; Gligorov, V.V.; Göbel, Carla; Golubkov, Dmitry; Golutvin, Andrey; Gomes, Alvaro; Gotti, Claudio; Grabalosa Gándara, Marc; Graciani Diaz, Ricardo; Granado Cardoso, Luis Alberto; Graugés, Eugeni; Graverini, Elena; Graziani, Giacomo; Grecu, Alexandru; Greening, Edward; Gregson, Sam; Griffith, Peter; Grillo, Lucia; Grünberg, Oliver; Gui, Bin; Gushchin, Evgeny; Guz, Yury; Gys, Thierry; Hadjivasiliou, Christos; Haefeli, Guido; Haen, Christophe; Haines, Susan; Hall, Samuel; Hamilton, Brian; Hampson, Thomas; Han, Xiaoxue; Hansmann-Menzemer, Stephanie; Harnew, Neville; Harnew, Samuel; Harrison, Jonathan; He, Jibo; Head, Timothy; Heijne, Veerle; Hennessy, Karol; Henrard, Pierre; Henry, Louis; Hernando Morata, Jose Angel; van Herwijnen, Eric; Heß, Miriam; Hicheur, Adlène; Hill, Donal; Hoballah, Mostafa; Hombach, Christoph; Hulsbergen, Wouter; Hunt, Philip; Hussain, Nazim; Hutchcroft, David; Hynds, Daniel; Idzik, Marek; Ilten, Philip; Jacobsson, Richard; Jaeger, Andreas; Jalocha, Pawel; Jans, Eddy; Jaton, Pierre; Jawahery, Abolhassan; Jing, Fanfan; John, Malcolm; Johnson, Daniel; Jones, Christopher; Joram, Christian; Jost, Beat; Jurik, Nathan; Kandybei, Sergii; Kanso, Walaa; Karacson, Matthias; Karbach, Moritz; Karodia, Sarah; Kelsey, Matthew; Kenyon, Ian; Ketel, Tjeerd; Khanji, Basem; Khurewathanakul, Chitsanu; Klaver, Suzanne; Klimaszewski, Konrad; Kochebina, Olga; Kolpin, Michael; Komarov, Ilya; Koopman, Rose; Koppenburg, Patrick; Korolev, Mikhail; Kozlinskiy, Alexandr; Kravchuk, Leonid; Kreplin, Katharina; Kreps, Michal; Krocker, Georg; Krokovny, Pavel; Kruse, Florian; Kucewicz, Wojciech; Kucharczyk, Marcin; Kudryavtsev, Vasily; Kurek, Krzysztof; Kvaratskheliya, Tengiz; La Thi, Viet Nga; Lacarrere, Daniel; Lafferty, George; Lai, Adriano; Lambert, Dean; Lambert, Robert W; Lanfranchi, Gaia; Langenbruch, Christoph; Langhans, Benedikt; Latham, Thomas; Lazzeroni, Cristina; Le Gac, Renaud; van Leerdam, Jeroen; Lees, Jean-Pierre; Lefèvre, Regis; Leflat, Alexander; Lefrançois, Jacques; Leo, Sabato; Leroy, Olivier; Lesiak, Tadeusz; Leverington, Blake; Li, Yiming; Likhomanenko, Tatiana; Liles, Myfanwy; Lindner, Rolf; Linn, Christian; Lionetto, Federica; Liu, Bo; Lohn, Stefan; Longstaff, Iain; Lopes, Jose; Lopez-March, Neus; Lowdon, Peter; Lucchesi, Donatella; Luo, Haofei; Lupato, Anna; Luppi, Eleonora; Lupton, Oliver; Machefert, Frederic; Machikhiliyan, Irina V; Maciuc, Florin; Maev, Oleg; Malde, Sneha; Malinin, Alexander; Manca, Giulia; Mancinelli, Giampiero; Mapelli, Alessandro; Maratas, Jan; Marchand, Jean François; Marconi, Umberto; Marin Benito, Carla; Marino, Pietro; Märki, Raphael; Marks, Jörg; Martellotti, Giuseppe; Martens, Aurelien; Martín Sánchez, Alexandra; Martinelli, Maurizio; Martinez Santos, Diego; Martinez Vidal, Fernando; Martins Tostes, Danielle; Massafferri, André; Matev, Rosen; Mathe, Zoltan; Matteuzzi, Clara; Mazurov, Alexander; McCann, Michael; McCarthy, James; McNab, Andrew; McNulty, Ronan; McSkelly, Ben; Meadows, Brian; Meier, Frank; Meissner, Marco; Merk, Marcel; Milanes, Diego Alejandro; Minard, Marie-Noelle; Moggi, Niccolò; Molina Rodriguez, Josue; Monteil, Stephane; Morandin, Mauro; Morawski, Piotr; Mordà, Alessandro; Morello, Michael Joseph; Moron, Jakub; Morris, Adam Benjamin; Mountain, Raymond; Muheim, Franz; Müller, Katharina; Mussini, Manuel; Muster, Bastien; Naik, Paras; Nakada, Tatsuya; Nandakumar, Raja; Nasteva, Irina; Needham, Matthew; Neri, Nicola; Neubert, Sebastian; Neufeld, Niko; Neuner, Max; Nguyen, Anh Duc; Nguyen, Thi-Dung; Nguyen-Mau, Chung; Nicol, Michelle; Niess, Valentin; Niet, Ramon; Nikitin, Nikolay; Nikodem, Thomas; Novoselov, Alexey; O'Hanlon, Daniel Patrick; Oblakowska-Mucha, Agnieszka; Obraztsov, Vladimir; Oggero, Serena; Ogilvy, Stephen; Okhrimenko, Oleksandr; Oldeman, Rudolf; Onderwater, Gerco; Orlandea, Marius; Otalora Goicochea, Juan Martin; Owen, Patrick; Oyanguren, Maria Arantza; Pal, Bilas Kanti; Palano, Antimo; Palombo, Fernando; Palutan, Matteo; Panman, Jacob; Papanestis, Antonios; Pappagallo, Marco; Pappalardo, Luciano; Parkes, Christopher; Parkinson, Christopher John; Passaleva, Giovanni; Patel, Girish; Patel, Mitesh; Patrignani, Claudia; Pearce, Alex; Pellegrino, Antonio; Penso, Gianni; Pepe Altarelli, Monica; Perazzini, Stefano; Perret, Pascal; Perrin-Terrin, Mathieu; Pescatore, Luca; Pesen, Erhan; Pessina, Gianluigi; Petridis, Konstantin; Petrolini, Alessandro; Picatoste Olloqui, Eduardo; Pietrzyk, Boleslaw; Pilař, Tomas; Pinci, Davide; Pistone, Alessandro; Playfer, Stephen; Plo Casasus, Maximo; Polci, Francesco; Poluektov, Anton; Polyakov, Ivan; Polycarpo, Erica; Popov, Alexander; Popov, Dmitry; Popovici, Bogdan; Potterat, Cédric; Price, Eugenia; Price, Joseph David; Prisciandaro, Jessica; Pritchard, Adrian; Prouve, Claire; Pugatch, Valery; Puig Navarro, Albert; Punzi, Giovanni; Qian, Wenbin; Rachwal, Bartolomiej; Rademacker, Jonas; Rakotomiaramanana, Barinjaka; Rama, Matteo; Rangel, Murilo; Raniuk, Iurii; Rauschmayr, Nathalie; Raven, Gerhard; Redi, Federico; Reichert, Stefanie; Reid, Matthew; dos Reis, Alberto; Ricciardi, Stefania; Richards, Sophie; Rihl, Mariana; Rinnert, Kurt; Rives Molina, Vincente; Robbe, Patrick; Rodrigues, Ana Barbara; Rodrigues, Eduardo; Rodriguez Perez, Pablo; Roiser, Stefan; Romanovsky, Vladimir; Romero Vidal, Antonio; Rotondo, Marcello; Rouvinet, Julien; Ruf, Thomas; Ruiz, Hugo; Ruiz Valls, Pablo; Saborido Silva, Juan Jose; Sagidova, Naylya; Sail, Paul; Saitta, Biagio; Salustino Guimaraes, Valdir; Sanchez Mayordomo, Carlos; Sanmartin Sedes, Brais; Santacesaria, Roberta; Santamarina Rios, Cibran; Santovetti, Emanuele; Sarti, Alessio; Satriano, Celestina; Satta, Alessia; Saunders, Daniel Martin; Savrina, Darya; Schiller, Manuel; Schindler, Heinrich; Schlupp, Maximilian; Schmelling, Michael; Schmidt, Burkhard; Schneider, Olivier; Schopper, Andreas; Schune, Marie Helene; Schwemmer, Rainer; Sciascia, Barbara; Sciubba, Adalberto; Semennikov, Alexander; Sepp, Indrek; Serra, Nicola; Serrano, Justine; Sestini, Lorenzo; Seyfert, Paul; Shapkin, Mikhail; Shapoval, Illya; Shcheglov, Yury; Shears, Tara; Shekhtman, Lev; Shevchenko, Vladimir; Shires, Alexander; Silva Coutinho, Rafael; Simi, Gabriele; Sirendi, Marek; Skidmore, Nicola; Skillicorn, Ian; Skwarnicki, Tomasz; Smith, Anthony; Smith, Edmund; Smith, Eluned; Smith, Jackson; Smith, Mark; Snoek, Hella; Sokoloff, Michael; Soler, Paul; Soomro, Fatima; Souza, Daniel; Souza De Paula, Bruno; Spaan, Bernhard; Sparkes, Ailsa; Spradlin, Patrick; Sridharan, Srikanth; Stagni, Federico; Stahl, Marian; Stahl, Sascha; Steinkamp, Olaf; Stenyakin, Oleg; Stevenson, Scott; Stoica, Sabin; Stone, Sheldon; Storaci, Barbara; Stracka, Simone; Straticiuc, Mihai; Straumann, Ulrich; Stroili, Roberto; Subbiah, Vijay Kartik; Sun, Liang; Sutcliffe, William; Swientek, Krzysztof; Swientek, Stefan; Syropoulos, Vasileios; Szczekowski, Marek; Szczypka, Paul; Szumlak, Tomasz; T'Jampens, Stephane; Teklishyn, Maksym; Tellarini, Giulia; Teubert, Frederic; Thomas, Christopher; Thomas, Eric; van Tilburg, Jeroen; Tisserand, Vincent; Tobin, Mark; Tolk, Siim; Tomassetti, Luca; Tonelli, Diego; Topp-Joergensen, Stig; Torr, Nicholas; Tournefier, Edwige; Tourneur, Stephane; Tran, Minh Tâm; Tresch, Marco; Tsaregorodtsev, Andrei; Tsopelas, Panagiotis; Tuning, Niels; Ubeda Garcia, Mario; Ukleja, Artur; Ustyuzhanin, Andrey; Uwer, Ulrich; Vacca, Claudia; Vagnoni, Vincenzo; Valenti, Giovanni; Vallier, Alexis; Vazquez Gomez, Ricardo; Vazquez Regueiro, Pablo; Vázquez Sierra, Carlos; Vecchi, Stefania; Velthuis, Jaap; Veltri, Michele; Veneziano, Giovanni; Vesterinen, Mika; Viaud, Benoit; Vieira, Daniel; Vieites Diaz, Maria; Vilasis-Cardona, Xavier; Vollhardt, Achim; Volyanskyy, Dmytro; Voong, David; Vorobyev, Alexey; Vorobyev, Vitaly; Voß, Christian; de Vries, Jacco; Waldi, Roland; Wallace, Charlotte; Wallace, Ronan; Walsh, John; Wandernoth, Sebastian; Wang, Jianchun; Ward, David; Watson, Nigel; Websdale, David; Whitehead, Mark; Wicht, Jean; Wiedner, Dirk; Wilkinson, Guy; Williams, Matthew; Williams, Mike; Wilschut, Hans; Wilson, Fergus; Wimberley, Jack; Wishahi, Julian; Wislicki, Wojciech; Witek, Mariusz; Wormser, Guy; Wotton, Stephen; Wright, Simon; Wyllie, Kenneth; Xie, Yuehong; Xing, Zhou; Xu, Zhirui; Yang, Zhenwei; Yuan, Xuhao; Yushchenko, Oleg; Zangoli, Maria; Zavertyaev, Mikhail; Zhang, Liming; Zhang, Wen Chao; Zhang, Yanxi; Zhelezov, Alexey; Zhokhov, Anatoly; Zhong, Liang; Zvyagin, Alexander

    2015-03-05

    The LHCb detector is a forward spectrometer at the Large Hadron Collider (LHC) at CERN. The experiment is designed for precision measurements of CP violation and rare decays of beauty and charm hadrons. In this paper the performance of the various LHCb sub-detectors and the trigger system are described, using data taken from 2010 to 2012. It is shown that the design criteria of the experiment have been met. The excellent performance of the detector has allowed the LHCb collaboration to publish a wide range of physics results, demonstrating LHCb's unique role, both as a heavy flavour experiment and as a general purpose detector in the forward region.

  15. ALFA Detector Control System

    CERN Document Server

    Oleiro Seabra, Luis Filipe; The ATLAS collaboration

    2015-01-01

    ALFA (Absolute Luminosity For ATLAS) is one of the sub-detectors of ATLAS (A Toroidal LHC Apparatus). The ALFA system is composed by four stations installed in the LHC tunnel 240 m away from the ATLAS interaction point. Each station has a vacuum and ventilation system, movement control and all the required electronics for signal processing. The Detector Control System (DCS) provides control and monitoring of several components and ensures the safe operation of the detector contributing to good Data Quality. This paper describes the ALFA DCS system including a detector overview, operation aspects and hardware control through a SCADA system, WinCC OA.

  16. ALFA Detector Control System

    CERN Document Server

    Oleiro Seabra, Luis Filipe; The ATLAS collaboration

    2015-01-01

    ALFA (Absolute Luminosity For ATLAS) is one of the sub-detectors of ATLAS/LHC. The ALFA system is composed by two stations installed in the LHC tunnel 240 m away from each side of the ATLAS interaction point. Each station has a vacuum and ventilation system, movement control and all the required electronic for signal processing. The Detector Control System (DCS) provides control and monitoring of several components and ensures the safe operation of the detector contributing to good Data Quality. This paper describes the ALFA DCS system including a detector overview, operation aspects and hardware control through a SCADA system, WinCC OA.

  17. The LHC detector challenge

    CERN Document Server

    Virdee, Tejinder S

    2004-01-01

    The Large Hadron Collider (LHC) from CERN, scheduled to come online in 2007, is a multi-TeV proton-proton collider with vast detectors. Two of the more significant detectors for LHC are ATLAS and CMS. Currently, both detectors are more than 65% complete in terms of financial commitment, and the experiments are being assembled at an increasing pace. ATLAS is being built directly in its underground cavern, whereas CMS is being assembled above ground. When completed, both detectors will aid researchers in determining what lies at the high-energy frontier, in particular the mechanism by which particles attain mass. (Edited abstract).

  18. Field transients of coherent terahertz synchrotron radiation accessed via time-resolving and correlation techniques

    Energy Technology Data Exchange (ETDEWEB)

    Pohl, A.; Hübers, H.-W. [Humboldt-Universität zu Berlin, Institute of Physics, Newtonstraße 15, 12489 Berlin (Germany); Institute of Optical Sensor Systems, German Aerospace Center (DLR), Rutherfordstrasse 29, 12489 Berlin (Germany); Semenov, A. [Institute of Optical Sensor Systems, German Aerospace Center (DLR), Rutherfordstrasse 29, 12489 Berlin (Germany); Hoehl, A.; Ulm, G. [Physikalisch-Technische Bundesanstalt (PTB), Abbestraße 2-12, 10587 Berlin (Germany); Ries, M.; Wüstefeld, G. [Helmholz-Zentrum Berlin, Albert-Einstein-Str. 15, 12489 Berlin (Germany); Ilin, K.; Thoma, P.; Siegel, M. [Institute of Micro- and Nanoelectronic Systems, Karlsruhe Institute of Technology (KIT), Hertzstrasse 16, 76187 Karlsruhe (Germany)

    2016-03-21

    Decaying oscillations of the electric field in repetitive pulses of coherent synchrotron radiation in the terahertz frequency range was evaluated by means of time-resolving and correlation techniques. Comparative analysis of real-time voltage transients of the electrical response and interferograms, which were obtained with an ultrafast zero-bias Schottky diode detector and a Martin-Puplett interferometer, delivers close values of the pulse duration. Consistent results were obtained via the correlation technique with a pair of Golay Cell detectors and a pair of resonant polarisation-sensitive superconducting detectors integrated on one chip. The duration of terahertz synchrotron pulses does not closely correlate with the duration of single-cycle electric field expected for the varying size of electron bunches. We largely attribute the difference to the charge density oscillations in electron bunches and to the low-frequency spectral cut-off imposed by both the synchrotron beamline and the coupling optics of our detectors.

  19. Self-powered flux detectors

    International Nuclear Information System (INIS)

    Shields, R.B.

    1983-02-01

    This bibliography attempts to cover the published literature on the class of radiation detectors most often referred to as 'self-powered'. For this purpose, self-powered detectors are defined as those that have two or more conducting electrodes separated by solid insulation and that generate a signal current without an external power source. Primary sensitivity is unrestricted, but it is usually to neutrons or gamma-rays. The main application is in the core of a nuclear reactor. All relevant facets of the subject are covered including: theory, experiment, development, design, manufacture, instrumentation and application. In addition to the usual reference information, various other designations are included where available, such as CONF-and abstract serial numbers. Where possible, a summary of the content is given with emphasis on specific results and conclusions. Indexing is by author and subject

  20. Performance of ATLAS tracking detector

    CERN Document Server

    Lacuesta, V; The ATLAS collaboration

    2012-01-01

    The track and vertex reconstruction algorithms of the ATLAS Inner Detector have demonstrated excellent performance in the early data from the LHC. However, the rapidly increas- ing number of interactions per bunch crossing introduces new challenges both in computational aspects and physics performance. The combination of both silicon and gas based detectors provides high precision impact parameter and momentum measurement of charged particles, with high efficiency and small fake rate. Vertex reconstruction is used to identify with high efficiency the hard scattering process and to measure the amount of pile-up interactions, both aspects are cru- cial for many physics analyses. The performance of track and vertex reconstruction efficiency and resolution achieved in the 2011 and 2012 data-taking period are presented.

  1. Whole body detectors for clinical applications

    International Nuclear Information System (INIS)

    Silar, J.

    The requirements are presented on the parameters of whole-body detectors suitable for clinical retention assays and the detector-patient configuration described. A whole-body detector was developed with an axial configuration of two pairs of large-volume scintillation detectors with NaI(Tl) crystals. One pair is placed under the bed, the other above the bed on which the patient is being examined. The axes of the crystals are located at a distance of 90 cm apart. The field of vision of the detector is described for the application of a 137 Cs source in the air and in a 24 cm layer of water. The positive characteristics of the detector are listed as being homogeneous sensitivity, energy resolution, long-term stability of signal pulse amplitude and average pulse rate in the integral mode. The results obtained show that the detector may be used to evaluate the level of contamination of persons by gamma emitters within the region of approximately 800 Bq to 74 MBq. The error in converting the number of signal pulses in the integral mode does not exceed 50% for gamma emitters with a photon energy above 30O keV. (J.B.)

  2. Optimization of a large-area detector-block based on SiPM and pixelated LYSO crystal arrays.

    Science.gov (United States)

    Calva-Coraza, E; Alva-Sánchez, H; Murrieta-Rodríguez, T; Martínez-Dávalos, A; Rodríguez-Villafuerte, M

    2017-10-01

    We present the performance evaluation of a large-area detector module based on the ArrayC-60035-64P, an 8×8 array of tileable, 7.2mm pitch, silicon photomultipliers (SiPM) by SensL, covering a total area of 57.4mm×57.4mm. We characterized the ArrayC-60035-64P, operating at room temperature, using LYSO pixelated crystal arrays of different pitch sizes (1.075, 1.430, 1.683, 2.080 and 2.280mm) to determine the resolvable crystal size. After an optimization process, a 7mm thick coupling light guide was used for all crystal pitches. To identify the interaction position a 16-channel (8 columns, 8 rows) symmetric charge division (SCD) readout board together with a center-of-gravity algorithm was used. Based on this, we assembled the detector modules using a 40×40 LYSO, 1.43mm pitch array, covering the total detector area. Calibration was performed using a 137 Cs source resulting in excellent crystal maps with minor geometric distortion, a mean 4.1 peak-to-valley ratio and 9.6% mean energy resolution for 662keV photons in the central region. The resolvability index was calculated in the x and y directions with values under 0.42 in all cases. We show that these large area SiPM arrays, combined with a 16-channel SCD readout board, can offer high spatial resolution, without processing a big number of signals, attaining excellent energy resolution and detector uniformity. Copyright © 2017 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  3. Digital autoradiography using silicon strip detectors

    Energy Technology Data Exchange (ETDEWEB)

    Overdick, M.

    1998-05-01

    Spatially resolving radiation detection systems operating in real time can be used to acquire autoradiographic images. An overview over alternatives to traditional autoradiography is given and the special features of these filmless methods are discussed. On this basis the design of a system for digital autoradiography using silicon strip detectors is presented. Special emphasis is put on the physical background of the detection process in the semiconductor and on the self-triggering read-out technique. The practical performance of the system is analyzed with respect to energy and spatial resolution. This analysis is complemented by case studies from cell biology (especially electrophoresis), botany and mineralogy. Also the results from a time-resolved autoradiographic experiment are presented. (orig.) 80 refs.

  4. Time-resolved fluorescence spectroscopy

    International Nuclear Information System (INIS)

    Gustavsson, Thomas; Mialocq, Jean-Claude

    2007-01-01

    This article addresses the evolution in time of light emitted by a molecular system after a brief photo-excitation. The authors first describe fluorescence from a photo-physical point of view and discuss the characterization of the excited state. Then, they explain some basic notions related to fluorescence characterization (lifetime and decays, quantum efficiency, so on). They present the different experimental methods and techniques currently used to study time-resolved fluorescence. They discuss basic notions of time resolution and spectral reconstruction. They briefly present some conventional methods: intensified Ccd cameras, photo-multipliers and photodiodes associated with a fast oscilloscope, and phase modulation. Other methods and techniques are more precisely presented: time-correlated single photon counting (principle, examples, and fluorescence lifetime imagery), streak camera (principle, examples), and optical methods like the Kerr optical effect (principle and examples) and fluorescence up-conversion (principle and theoretical considerations, examples of application)

  5. Design and Implementation of the ATLAS Detector Control System

    CERN Document Server

    Boterenbrood, H; Cook, J; Filimonov, V; Hallgren, B I; Heubers, W P J; Khomoutnikov, V; Ryabov, Yu; Varela, F

    2004-01-01

    The overall dimensions of the ATLAS experiment and its harsh environment, due to radiation and magnetic field, represent new challenges for the implementation of the Detector Control System. It supervises all hardware of the ATLAS detector, monitors the infrastructure of the experiment, and provides information exchange with the LHC accelerator. The system must allow for the operation of the different ATLAS sub-detectors in stand-alone mode, as required for calibration and debugging, as well as the coherent and integrated operation of all sub-detectors for physics data taking. For this reason, the Detector Control System is logically arranged to map the hierarchical organization of the ATLAS detector. Special requirements are placed onto the ATLAS Detector Control System because of the large number of distributed I/O channels and of the inaccessibility of the equipment during operation. Standardization is a crucial issue for the design and implementation of the control system because of the large variety of e...

  6. Development of superconducting tunnel junction radiation detectors

    Energy Technology Data Exchange (ETDEWEB)

    Katagiri, Masaki; Kishimoto, Maki; Ukibe, Masahiro; Nakamura, Tatsuya; Nakazawa, Masaharu [Japan Atomic Energy Research Inst., Tokyo (Japan); Kurakado, Masahiko; Ishibashi, Kenji; Maehata, Keisuke

    1998-07-01

    Study on development of high energy resolution X-ray detector using superconducting tunnel junction (STJ) for radiation detection was conducted for 5 years under cooperation of University of Tokyo group and Kyushu University group by Quantum measurement research group of Advanced fundamental research center of JAERI. As the energy resolution of STJ could be obtained better results than that of Si semiconductor detector told to be actually best at present, this study aimed to actualize an X-ray detector usable for the experimental field and to elucidate radiation detection mechanism due to STJ. The STJ element used for this study was the one developed by Kurakado group of Nippon Steel Corp. As a results, some technical problems were almost resolved, which made some trouble when using the STJ element to detection element of X-ray spectrometer. In order to make the X-ray detector better, it is essential to manufacture a STJ element and develop serial junction type STJ element on the base of optimization of the element structure and selection and single crystallization of new superconducting materials such as Ta and others, activating the research results. (G.K.)

  7. ALICE Photon Multiplicity Detector

    CERN Multimedia

    Nayak, T

    2013-01-01

    Photon Multiplicity Detector (PMD) measures the multiplicity and spatial distribution of photons in the forward region of ALICE on a event-by-event basis. PMD is a pre-shower detector having fine granularity and full azimuthal coverage in the pseudo-rapidity region 2.3 < η < 3.9.

  8. New detector concepts

    International Nuclear Information System (INIS)

    Kemmer, J.; Lutz, G.

    1986-07-01

    On the basis of the semiconductor drift chamber many new detectors are proposed, which enable the determination of energy, energy loss, position and penetration depth of radiation. A novel integrated transistor-detector configuration allows non destructive repeated readout and amplification of the signal. The concept may be used for the construction of one or two-dimensional PIXEL arrays. (orig.)

  9. Stanford's big new detector

    International Nuclear Information System (INIS)

    Anon.

    1984-01-01

    A detector constructed for the Standford Linear Collider is described. It consists of a central drift chamber in the field of a surrounding superconducting solenoid. Furthermore included are a Cherenkov ring imaging detector for particle identification and a liquid argon calorimeter. (HSI).

  10. CMS Detector Posters

    CERN Multimedia

    2016-01-01

    CMS Detector posters (produced in 2000): CMS installation CMS collaboration From the Big Bang to Stars LHC Magnetic Field Magnet System Trackering System Tracker Electronics Calorimetry Eletromagnetic Calorimeter Hadronic Calorimeter Muon System Muon Detectors Trigger and data aquisition (DAQ) ECAL posters (produced in 2010, FR & EN): CMS ECAL CMS ECAL-Supermodule cooling and mechatronics CMS ECAL-Supermodule assembly

  11. Pixel detector readout chip

    CERN Multimedia

    1991-01-01

    Close-up of a pixel detector readout chip. The photograph shows an aera of 1 mm x 2 mm containing 12 separate readout channels. The entire chip contains 1000 readout channels (around 80 000 transistors) covering a sensitive area of 8 mm x 5 mm. The chip has been mounted on a silicon detector to detect high energy particles.

  12. Drift chamber detectors

    International Nuclear Information System (INIS)

    Duran, I.; Martinez Laso, L.

    1989-01-01

    A review of High Energy Physics detectors based on drift chambers is presented. The ionization, drift diffusion, multiplication and detection principles are described. Most common drift media are analysied, and a classification of the detectors according to its geometry is done. Finally the standard read-out methods are displayed and the limits of the spatial resolution are discussed. (Author)

  13. Drift Chambers detectors

    International Nuclear Information System (INIS)

    Duran, I.; Martinez laso, L.

    1989-01-01

    We present here a review of High Energy Physics detectors based on drift chambers. The ionization, drift diffusion, multiplication and detection principles are described. Most common drift media are analysed, and a classification of the detectors according to its geometry is done. Finally the standard read-out methods are displayed and the limits of the spatial resolution are discussed. (Author) 115 refs

  14. Solid state track detectors

    International Nuclear Information System (INIS)

    Reuther, H.

    1976-11-01

    This paper gives a survey of the present state of the development and the application of solid state track detectors. The fundamentals of the physical and chemical processes of the track formation and development are explained, the different detector materials and their registration characteristics are mentioned, the possibilities of the experimental practice and the most variable applications are discussed. (author)

  15. LHCb detector performance

    NARCIS (Netherlands)

    Aaij, R.; Adeva, B.; Adinol, M.; Affolder, A.; Ajaltouni, Z.; Akar, S.; Albrecht, J.; Alessio, F.; Alexander, M.; Ali, S.; Alkhazov, G.; Alvarez Cartelle, P.; Alves, A. A.; Amato, S.; Amerio, S.; Amhis, Y.; An, L.; Anderlini, L.; Anderson, J.; Andreassen, R.; Andreotti, M.; Andrews, J. E.; Appleby, R. B.; Gutierrez, O. Aquines; Archilli, F.; Artamonov, A.; Artuso, M.; Aslanides, E.; Auriemma, G.; Baalouch, M.; Bachmann, S.; Back, J. J.; Badalov, A.; Baesso, C.; Baldini, W.; Barlow, R. J.; Barschel, C.; Barsuk, S.; Barter, W.; Batozskaya, V.; Battista, V.; Bay, A.; Beaucourt, L.; Beddow, J.; Bedeschi, F.; Bediaga, I.; Belogurov, S.; Onderwater, C. J. G.; Pellegrino, A.; Wilschut, H. W.

    2015-01-01

    The LHCb detector is a forward spectrometer at the Large Hadron Collider (LHC) at CERN. The experiment is designed for precision measurements of CP violation and rare decays of beauty and charm hadrons. In this paper the performance of the various LHCb sub-detectors and the trigger system are

  16. The LDC detector concept

    Indian Academy of Sciences (India)

    Abstract. In preparation of the experimental program at the international linear collider (ILC), the large detector concept (LDC) is being developed. The main points of the LDC are a large volume gaseous tracking system, combined with high precision vertex detector and an extremely granular calorimeter. The main design ...

  17. Detector Systems at CLIC

    CERN Document Server

    Simon, Frank

    2011-01-01

    The Compact Linear Collider CLIC is designed to deliver e+e- collisions at a center of mass energy of up to 3 TeV. The detector systems at this collider have to provide highly efficient tracking and excellent jet energy resolution and hermeticity for multi-TeV final states with multiple jets and leptons. In addition, the detector systems have to be capable of distinguishing physics events from large beam-induced background at a crossing frequency of 2 GHz. Like for the detector concepts at the ILC, CLIC detectors are based on event reconstruction using particle flow algorithms. The two detector concepts for the ILC, ILD and SID, were adapted for CLIC using calorimeters with dense absorbers limiting leakage through increased compactness, as well as modified forward and vertex detector geometries and precise time stamping to cope with increased background levels. The overall detector concepts for CLIC are presented, with particular emphasis on the main detector and engineering challenges, such as: the ultra-thi...

  18. Future particle detector systems

    International Nuclear Information System (INIS)

    Clark, Allan G.

    2000-01-01

    Starting with a short summary of the major new experimental physics programs, we attempt to motivate the reasons why existing general-purpose detectors at Hadron Colliders are what they are, why they are being upgraded, and why new facilities are being constructed. The CDF and ATLAS detectors are used to illustrate these motivations. Selected physics results from the CDF experiment provide evidence for limitations on the detector performance, and new physics opportunities motivate both machine and detector upgrades. This is discussed with emphasis on the improved physics reach of the CDF experiment at the Fermilab Tevatron (√(s)=2 TeV). From 2005, the Large Hadron Collider (LHC) at CERN will become operational at a collision energy of √(s)=14 TeV, seven times larger than at the Tevatron Collider. To exploit the physics capability of the LHC, several large detectors are being constructed. The detectors are significantly more complex than those at the Tevatron Collider because of physics and operational constraints. The detector design and technology of the aspects of the large general-purpose detector ATLAS is described

  19. Developments on RICH detectors

    International Nuclear Information System (INIS)

    Besson, P.; Bourgeois, P.

    1996-01-01

    The RICH (ring imaging Cherenkov) detector which is dedicated to Cherenkov radiation detection is described. An improvement made by replacing photo sensible vapor with solid photocathode is studied. A RICH detector prototype with a CsI photocathode has been built in Saclay and used with Saturne. The first results are presented. (A.C.)

  20. ALICE Silicon Strip Detector

    CERN Multimedia

    Nooren, G

    2013-01-01

    The Silicon Strip Detector (SSD) constitutes the two outermost layers of the Inner Tracking System (ITS) of the ALICE Experiment. The SSD plays a crucial role in the tracking of the particles produced in the collisions connecting the tracks from the external detectors (Time Projection Chamber) to the ITS. The SSD also contributes to the particle identification through the measurement of their energy loss.

  1. Identification unit for phoswich and phostron detectors

    International Nuclear Information System (INIS)

    Pouxe, J.; Stassi, P.; Dauchy, A.; Giorni, A.; Morand, C.; Chambon, B.; Cheynis, B.; Drain, D.; Pastor, C.

    1984-01-01

    In the last few years the phoswich detector techniques have become a convenient solution to detect light particles emitted in heavy ion induced reactions. Generally the signal delivered by the detectors are integrated within two lapses of time by an analog-to-digital converter triggered by the same signal. When time of flight information is needed the detectors are placed far away from the target and the analog to digital converter must have one gate for each channel because of the jitter in the time of flight of the different particles. As soon as the number of detectors increases this solution becomes too expensive. For this reason a new simple and cheap method is proposed where the particle identification is given by the measurement of data taken from the anode output signal

  2. CVD diamond detectors for ionizing radiation

    CERN Document Server

    Friedl, M; Bauer, C; Berfermann, E; Bergonzo, P; Bogani, F; Borchi, E; Brambilla, A; Bruzzi, Mara; Colledani, C; Conway, J; Dabrowski, W; Delpierre, P A; Deneuville, A; Dulinski, W; van Eijk, B; Fallou, A; Fizzotti, F; Foulon, F; Gan, K K; Gheeraert, E; Grigoriev, E; Hallewell, G D; Hall-Wilton, R; Han, S; Hartjes, F G; Hrubec, Josef; Husson, D; Kagan, H; Kania, D R; Kaplon, J; Karl, C; Kass, R; Knöpfle, K T; Krammer, Manfred; Lo Giudice, A; Lü, R; Manfredi, P F; Manfredotti, C; Marshall, R D; Meier, D; Mishina, M; Oh, A; Pan, L S; Palmieri, V G; Pernegger, H; Pernicka, Manfred; Peitz, A; Pirollo, S; Polesello, P; Pretzl, Klaus P; Re, V; Riester, J L; Roe, S; Roff, D G; Rudge, A; Schnetzer, S R; Sciortino, S; Speziali, V; Stelzer, H; Stone, R; Tapper, R J; Tesarek, R J; Thomson, G B; Trawick, M L; Trischuk, W; Vittone, E; Walsh, A M; Wedenig, R; Weilhammer, Peter; Ziock, H J; Zöller, M

    1999-01-01

    In future HEP accelerators, such as the LHC (CERN), detectors and electronics in the vertex region of the experiments will suffer from extreme radiation. Thus radiation hardness is required for both detectors and electronics to survive in this harsh environment. CVD diamond, which is investigated by the RD42 Collaboration at CERN, can meet these requirements. Samples of up to 2*4 cm/sup 2/ have been grown and refined for better charge collection properties, which are measured with a beta source or in a test beam. A large number of diamond samples has been irradiated with hadrons to fluences of up to 5*10/sup 15/ cm/sup -2/ to study the effects of radiation. Both strip and pixel detectors were prepared in various geometries. Samples with strip metallization have been tested with both slow and fast readout electronics, and the first diamond pixel detector proved fully functional with LHC electronics. (16 refs).

  3. CVD diamond detectors for ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    Friedl, M. E-mail: markus.friedl@cern.ch; Adam, W.; Bauer, C.; Berdermann, E.; Bergonzo, P.; Bogani, F.; Borchi, E.; Brambilla, A.; Bruzzi, M.; Colledani, C.; Conway, J.; Dabrowski, W.; Delpierre, P.; Deneuville, A.; Dulinski, W.; Eijk, B. van; Fallou, A.; Fizzotti, F.; Foulon, F.; Gan, K.K.; Gheeraert, E.; Grigoriev, E.; Hallewell, G.; Hall-Wilton, R.; Han, S.; Hartjes, F.; Hrubec, J.; Husson, D.; Kagan, H.; Kania, D.; Kaplon, J.; Karl, C.; Kass, R.; Knoepfle, K.T.; Krammer, M.; Logiudice, A.; Lu, R.; Manfredi, P.F.; Manfredotti, C.; Marshall, R.D.; Meier, D.; Mishina, M.; Oh, A.; Pan, L.S.; Palmieri, V.G.; Pernegger, H.; Pernicka, M.; Peitz, A.; Pirollo, S.; Polesello, P.; Pretzl, K.; Re, V.; Riester, J.L.; Roe, S.; Roff, D.; Rudge, A.; Schnetzer, S.; Sciortino, S.; Speziali, V.; Stelzer, H.; Stone, R.; Tapper, R.J.; Tesarek, R.; Thomson, G.B.; Trawick, M.; Trischuk, W.; Vittone, E.; Walsh, A.M.; Wedenig, R.; Weilhammer, P.; Ziock, H.; Zoeller, M

    1999-10-01

    In future HEP accelerators, such as the LHC (CERN), detectors and electronics in the vertex region of the experiments will suffer from extreme radiation. Thus radiation hardness is required for both detectors and electronics to survive in this harsh environment. CVD diamond, which is investigated by the RD42 Collaboration at CERN, can meet these requirements. Samples of up to 2x4 cm{sup 2} have been grown and refined for better charge collection properties, which are measured with a {beta} source or in a test beam. A large number of diamond samples has been irradiated with hadrons to fluences of up to 5x10{sup 15} cm{sup -2} to study the effects of radiation. Both strip and pixel detectors were prepared in various geometries. Samples with strip metallization have been tested with both slow and fast readout electronics, and the first diamond pixel detector proved fully functional with LHC electronics. (author)

  4. CVD diamond detectors for ionizing radiation

    Science.gov (United States)

    Friedl, M.; Adam, W.; Bauer, C.; Berdermann, E.; Bergonzo, P.; Bogani, F.; Borchi, E.; Brambilla, A.; Bruzzi, M.; Colledani, C.; Conway, J.; Dabrowski, W.; Delpierre, P.; Deneuville, A.; Dulinski, W.; van Eijk, B.; Fallou, A.; Fizzotti, F.; Foulon, F.; Gan, K. K.; Gheeraert, E.; Grigoriev, E.; Hallewell, G.; Hall-Wilton, R.; Han, S.; Hartjes, F.; Hrubec, J.; Husson, D.; Kagan, H.; Kania, D.; Kaplon, J.; Karl, C.; Kass, R.; Knöpfle, K. T.; Krammer, M.; Logiudice, A.; Lu, R.; Manfredi, P. F.; Manfredotti, C.; Marshall, R. D.; Meier, D.; Mishina, M.; Oh, A.; Pan, L. S.; Palmieri, V. G.; Pernegger, H.; Pernicka, M.; Peitz, A.; Pirollo, S.; Polesello, P.; Pretzl, K.; Re, V.; Riester, J. L.; Roe, S.; Roff, D.; Rudge, A.; Schnetzer, S.; Sciortino, S.; Speziali, V.; Stelzer, H.; Stone, R.; Tapper, R. J.; Tesarek, R.; Thomson, G. B.; Trawick, M.; Trischuk, W.; Vittone, E.; Walsh, A. M.; Wedenig, R.; Weilhammer, P.; Ziock, H.; Zoeller, M.; RD42 Collaboration

    1999-10-01

    In future HEP accelerators, such as the LHC (CERN), detectors and electronics in the vertex region of the experiments will suffer from extreme radiation. Thus radiation hardness is required for both detectors and electronics to survive in this harsh environment. CVD diamond, which is investigated by the RD42 Collaboration at CERN, can meet these requirements. Samples of up to 2×4 cm2 have been grown and refined for better charge collection properties, which are measured with a β source or in a testbeam. A large number of diamond samples has been irradiated with hadrons to fluences of up to 5×10 15 cm-2 to study the effects of radiation. Both strip and pixel detectors were prepared in various geometries. Samples with strip metallization have been tested with both slow and fast readout electronics, and the first diamond pixel detector proved fully functional with LHC electronics.

  5. MUON DETECTORS: RPC

    CERN Multimedia

    Pierluigi Paolucci

    2013-01-01

    In the second part of 2013 the two main activities of the RPC project are the reparation and maintenance of the present system and the construction and installation of the RE4 system. Since the opening of the barrel, repair activities on the gas, high-voltage and electronic systems are being done in parallel, in agreement with the CMS schedule. In YB0, the maintenance of the RPC detector was in the shadow of other interventions, nevertheless the scaffolding turned out to be a good solution for our gas leaks searches. Here we found eight leaking channels for about 100 l/h in total. 10 RPC/DT modules were partially extracted –– 90 cm –– in YB0, YB–1 and YB–2 to allow for the replacement of FE and LV distribution boards. Intervention was conducted on an additional two chambers on the positive endcap to solve LV and threshold control problems. Until now we were able to recover 0.67% of the total number of RPC electronic channels (1.5% of the channels...

  6. MUON DETECTORS: RPC

    CERN Multimedia

    P. Paolucci

    2012-01-01

      2011 data-taking was very satisfactory for both the RPC detector and trigger. The RPC system ran very smoothly in 2011, showing an excellent stability and very high data-tacking efficiency. Data loss for RPC was about 0.37%, corresponding to 19 pb−1. Most of the performance studies, based on 2011 data, are now completed and the results have been already approved by CMS to be presented at the RPC 2012 conference (February 2012 at LNF). During 2011, the number of disconnected chambers increased from six to eight corresponding to 0.8% of the full system, while the single-gap-mode chambers increased from 28 to 31. Most of the problematic chambers are due to bad high-voltage connection and electronic failures that can be solved only during the 2013-2014 Long Shutdown. 98.4% of the electronic channels were operational. The average detection efficiency in 2011 was about 95%, which was the same value measured during the HV scan done at the beginning of the 2011 data-taking. Efficiency has be...

  7. Microwave hematoma detector

    Science.gov (United States)

    Haddad, Waleed S.; Trebes, James E.; Matthews, Dennis L.

    2001-01-01

    The Microwave Hematoma Detector is a non-invasive device designed to detect and localize blood pooling and clots near the outer surface of the body. While being geared towards finding sub-dural and epi-dural hematomas, the device can be used to detect blood pooling anywhere near the surface of the body. Modified versions of the device can also detect pneumothorax, organ hemorrhage, atherosclerotic plaque in the carotid arteries, evaluate perfusion (blood flow) at or near the body surface, body tissue damage at or near the surface (especially for burn assessment) and be used in a number of NDE applications. The device is based on low power pulsed microwave technology combined with a specialized antenna, signal processing/recognition algorithms and a disposable cap worn by the patient which will facilitate accurate mapping of the brain and proper function of the instrument. The invention may be used for rapid, non-invasive detection of sub-dural or epi-dural hematoma in human or animal patients, detection of hemorrhage within approximately 5 cm of the outer surface anywhere on a patient's body.

  8. MUON DETECTORS: CSC

    CERN Multimedia

    R. Breedon

    Figure 2: Five ME4/2 chambers mounted on the +endcap. At the end of June, five large, outer cathode strip chambers (CSC) that were produced as spares during the original production were mounted on part of the disk space reserved for ME4/2 on the positive endcap (Fig. 2). The chambers were cabled, attached to services, and fully integrated and commissioned into the CSC DAQ and trigger systems. Comprising almost a full trigger sector, CMS will be able to test the significant improvement the trigger efficiency of the EMU system that the presence of the full ME4/2 ring is expected to bring. The return of beam in November was observed as “splash” events in the CSCs in which the detectors were showered with a huge number of particles at the same time. Although the CSCs were operating at a lower standby voltage the multiple hits on a strips could not be individually distinguished.&am...

  9. MUON DETECTORS: DT

    CERN Multimedia

    R.Carlin

    2010-01-01

    DT operation during 2010 LHC collisions, both in proton-proton and heavy ions, has been outstanding. The DT downtime has been below 0.1% throughout the whole year, mainly caused by the manual Resync commands that took around a minute for being processed. An automatic resynchronisation procedure has been enabled by August 27 and since then the downtime has been negligible (though constantly monitored). The need for these Resync commands is related to sporadic noise events that occasionally fill the RO buffers or unlock the readout links. Their rate is low, in the order of a few per week. Besides that, only one pp collisions run (1 hour 30 minutes run) has been marked as bad for DT, because of an incident with a temperature sensor that triggered a false alarm and powered off one wheel. Nevertheless, quite a large number of interventions (>30) have been made in the cavern during the year, in order to keep such a large fraction of the detector operational. Most of those are due to the overheating of the ...

  10. MUON DETECTORS: DT

    CERN Multimedia

    C. Fernandez Bedova and M. Dallavalle

    2010-01-01

    After successful operation during the 2009 LHC run, a number of fixes and improvements were carried out on the DT system the winter shutdown. The main concern was related with the impact of the extensive water leak that happened in October in YE+1. Opening of CMS end-caps allowed the DT crew to check if any Minicrates (containing the first level of readout and trigger electronics) in YB+2 and YB-2 were flooded with water. The affected region from top sectors in YB+2 reaches down to the bottom sectors in YB-2 following the water path in the barrel from end to end. No evidence of water penetration was observed, though the passage of water left oxidation and white streaks on the iron and components. In particular, large signs of oxidation have been seen on the YB-2 MB1 top and bottom stations. Review of the impact in YB+1 remains for future openings of CMS wheels, and at present, effort is focused on setting up the water leak detection system in the detector. Another important issue during this shutd...

  11. The GDH-Detector

    CERN Document Server

    Helbing, K; Fausten, M; Menze, D; Michel, T; Nagel, A; Ryckbosch, D; Speckner, T; Vyver, R V D; Zeitler, G

    2002-01-01

    For the GDH-Experiment at ELSA, the helicity dependent total photoabsorption cross-section is to be determined. These measurements will be performed with the newly developed GDH-Detector which is presented here. The concept of the GDH-Detector is to detect at least one reaction product from all possible hadronic processes with almost complete acceptance concerning solid angle and efficiency. This is realized by an arrangement of scintillators and lead. The overall acceptance for hadronic processes is better than 99%. The electromagnetic background is suppressed by about five orders of magnitude by means of a threshold Cherenkov detector. In dedicated tests, it has been demonstrated that all individual components of the GDH-Detector fulfill the design goals. Measurements of unpolarized total photoabsorption cross-sections were performed to ensure that the complete GDH-Detector is operational.

  12. Introduction to detectors

    CERN Document Server

    Walenta, Albert H

    1995-01-01

    Concepts for momentum measurements,particle identification and energy measurements (calorimeters) as well for imaging applications in medecine, biology and industry (non destructive testing) will be put into relation to the specific detection princip In particular the resolution for position, time, energy and intensity measurement and the efficiency will be discussed. Signal extraction,electronic signal processing and principles of information capture will close the logic circle to the input : the radiation properties.The lecture will provide some sources for data tables and small demonstration computer programs f The basic detector physics as interaction of radiation with matter, information transport via free charges,photons and phonons and the signal formation will be presented in some depth with emphasis on the influence on specific parameters for detector The lecture will cover the most popular detector principles, gas detectors (ion chambers,MPWC's and MSGC's), semiconductor detectors scintillators and ...

  13. ATLAS ITk Pixel detector

    CERN Document Server

    Gemme, Claudia; The ATLAS collaboration

    2016-01-01

    The high luminosity upgrade of the LHC (HL-LHC) in 2026 will provide new challenge to the ATLAS tracker. The current inner detector will be replaced with a whole silicon tracker which will consist of a five barrel layer Pixel detector surrounded by a four barrel layer Strip detector. The expected high radiation level are requiring the development of upgraded silicon sensors as well as new a front-end chip. The dense tracking environment will require finer granularity detectors. The data rates will require new technologies for high bandwidth data transmission and handling. The current status of the HL-LHC ATLA Pixel detector developments as well as the various layout options will be reviewed.

  14. Undepleted silicon detectors

    International Nuclear Information System (INIS)

    Rancoita, P.G.; Seidman, A.

    1985-01-01

    Large-size silicon detectors employing relatively low resistivity material can be used in electromagnetic calorimetry. They can operate in strong magnetic fields, under geometric constraints and with microstrip detectors a high resolution can be achieved. Low noise large capacitance oriented electronics was developed to enable good signal-to-noise ratio for single relativistic particles traversing large area detectors. In undepleted silicon detectors, the charge migration from the field-free region has been investigated by comparing the expected peak position (from the depleted layer only) of the energy-loss of relativistic electrons with the measured one. Furthermore, the undepleted detectors have been employed in a prototype of Si/W electromagnetic colorimeter. The sensitive layer was found to be systematically larger than the depleted one

  15. Advanced far infrared detectors

    International Nuclear Information System (INIS)

    Haller, E.E.

    1993-05-01

    Recent advances in photoconductive and bolometric semiconductor detectors for wavelength 1 mm > λ > 50 μm are reviewed. Progress in detector performance in this photon energy range has been stimulated by new and stringent requirements for ground based, high altitude and space-borne telescopes for astronomical and astrophysical observations. The paper consists of chapters dealing with the various types of detectors: Be and Ga doped Ge photoconductors, stressed Ge:Ga devices and neutron transmutation doped Ge thermistors. Advances in the understanding of basic detector physics and the introduction of modern semiconductor device technology have led to predictable and reliable fabrication techniques. Integration of detectors into functional arrays has become feasible and is vigorously pursued by groups worldwide

  16. Charged corpuscular beam detector

    Energy Technology Data Exchange (ETDEWEB)

    Hikawa, H; Nishikawa, Y

    1970-09-29

    The present invention relates to a charged particle beam detector which prevents transient phenomena disturbing the path and focusing of a charged particle beam travelling through a mounted axle. The present invention provides a charged particle beam detector capable of decreasing its reaction to the charge in energy of the charged particle beam even if the relative angle between the mounted axle and the scanner is unstable. The detector is characterized by mounting electrically conductive metal pieces of high melting point onto the face of a stepped, heat-resistant electric insulating material such that the pieces partially overlap each other and individually provide electric signals, whereby the detector is no longer affected by the beam. The thickness of the metal piece is selected so that an eddy current is not induced therein by an incident beam, thus the incident beam is not affected. The detector is capable of detecting a misaligned beam since the metal pieces partially overlap each other.

  17. Nuclear Material Accountability Applications of a Continuous Energy and Direction Gamma Ray Detector

    International Nuclear Information System (INIS)

    Gerts, David; Bean, Robert; Paff, Marc

    2010-01-01

    The Idaho National Laboratory has recently developed a detector system based on the principle of a Wilson cloud chamber that gives the original energy and direction to a gamma ray source. This detector has the properties that the energy resolution is continuous and the direction to the source can be resolved to desired fidelity. Furthermore, the detector has low power requirements, is durable, operates in widely varying environments, and is relatively cheap to produce. This detector is expected, however, to require significant time to perform measurements. To mitigate the significant time for measurements, the detector is expected to scale to very large sizes with a linear increase in cost. For example, the proof of principle detector is approximately 30,000 cm3. This work describes the technical results that lead to these assertions. Finally, the applications of this detector are described in the context of nuclear material accountability.

  18. The Solenoidal Detector Collaboration silicon detector system

    International Nuclear Information System (INIS)

    Ziock, H.J.; Gamble, M.T.; Miller, W.O.; Palounek, A.P.T.; Thompson, T.C.

    1992-01-01

    Silicon tracking systems will be fundamental components of the tracking systems for both planned major SSC experiments. Despite its seemingly small size, it occupies a volume of more than 5 meters in length and 1 meter in diameter and is an order of magnitude larger than any silicon detector system previously built. This report discusses its design and operation

  19. CDF [Collider Detector at Fermilab] detector simulation

    International Nuclear Information System (INIS)

    Freeman, J.

    1987-12-01

    The Collider Detector at Fermilab (CDF) uses several different simulation programs, each tuned for specific applications. The programs rely heavily on the extensive test beam data that CDF has accumulated. Sophisticated shower parameterizations are used, yielding enormous gains in speed over full cascade programs. 3 refs., 5 figs

  20. Highly Resolved Sub-Terahertz Vibrational Spectroscopy of Biological Macromolecules and Bacteria Cells

    Science.gov (United States)

    2016-07-01

    HIGHLY RESOLVED SUB-TERAHERTZ VIBRATIONAL SPECTROSCOPY OF BIOLOGICAL MACROMOLECULES AND BACTERIA CELLS ECBC...SUBTITLE Highly Resolved Sub-Terahertz Vibrational Spectroscopy of Biological Macromolecules and Bacteria Cells 5a. CONTRACT NUMBER W911SR-14-P...22 4.3 Bacteria THz Study

  1. Pitch angle resolved measurements of escaping charged fusion products in TFTR

    International Nuclear Information System (INIS)

    Zweben, S.J.

    1989-01-01

    Measurements of the flux of charged fusion products escaping from the TFTR plasma have been made with a new type of detector which can resolve the particle flux vs. pitch angle, energy, and time. The design of this detector is described, and results from the 1987 TFTR run are presented. These results are roughly consistent with predictions from a simple first-orbit particle loss model with respect to the pitch angle, energy, time, and plasma current dependence of the signals. 11 refs., 9 figs

  2. Pitch angle resolved measurements of escaping charged fusion products in TFTR

    Energy Technology Data Exchange (ETDEWEB)

    Zweben, S.J.

    1989-01-01

    Measurements of the flux of charged fusion products escaping from the TFTR plasma have been made with a new type of detector which can resolve the particle flux vs. pitch angle, energy, and time. The design of this detector is described, and results from the 1987 TFTR run are presented. These results are roughly consistent with predictions from a simple first-orbit particle loss model with respect to the pitch angle, energy, time, and plasma current dependence of the signals. 11 refs., 9 figs.

  3. Direct observation of spin-resolved full and empty electron states in ferromagnetic surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Berti, G., E-mail: giulia.berti@polimi.it; Calloni, A.; Brambilla, A.; Bussetti, G.; Duò, L.; Ciccacci, F. [Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133, Milano (Italy)

    2014-07-15

    We present a versatile apparatus for the study of ferromagnetic surfaces, which combines spin-polarized photoemission and inverse photoemission spectroscopies. Samples can be grown by molecular beam epitaxy and analyzed in situ. Spin-resolved photoemission spectroscopy analysis is done with a hemispherical electron analyzer coupled to a 25 kV-Mott detector. Inverse photoemission spectroscopy experiments are performed with GaAs crystals as spin-polarized electron sources and a UV bandpass photon detector. As an example, measurements on the oxygen passivated Fe(100)-p(1×1)O surface are presented.

  4. α-spectra hyperfine structure resolution by silicon planar detectors

    International Nuclear Information System (INIS)

    Eremin, V.K.; Verbitskaya, E.M.; Strokan, N.B.; Sukhanov, V.L.; Malyarenko, A.M.

    1986-01-01

    The lines with 13 keV step from the main one is α-spectra of nuclei with an odd number of nucleons take place. Silicon planar detectors n-Si with the operation surface of 10 mm 2 are developed for resolution of this hyperfine structure. The mechanism of losses in detectors for short-range-path particles is analyzed. The results of measurements from detectors with 10 keV resolution are presented

  5. cap alpha. -spectra hyperfine structure resolution by silicon planar detectors

    Energy Technology Data Exchange (ETDEWEB)

    Eremin, V K; Verbitskaya, E M; Strokan, N B; Sukhanov, V L; Malyarenko, A M

    1986-10-01

    The lines with 13 keV step from the main one is ..cap alpha..-spectra of nuclei with an odd number of nucleons take place. Silicon planar detectors n-Si with the operation surface of 10 mm/sup 2/ are developed for resolution of this hyperfine structure. The mechanism of losses in detectors for short-range-path particles is analyzed. The results of measurements from detectors with 10 keV resolution are presented.

  6. Space and time resolved observations of hot spots dynamics in a vacuum spark discharge

    International Nuclear Information System (INIS)

    Chuaqui, H.; Favre, M.; Saavedra, R.; Wyndham, E.

    1996-01-01

    Experimental observations of the plasma formations in a vacuum spark discharge are presented. A low power Nd:YAG laser pulse incident onto a titanium cathode initiates the discharge. The evolution of the titanium plasma electron density and temperature is followed both in the visible and the soft X-ray part of the spectrum. The former uses a novel micro holographic interferometric technique permitting a spatial resolution better than 20 μm. The probing beam is a 6 ns frequency doubled Nd:YAG laser. The latter emission is resolved using a number of different methods. The spatial information is derived from a 1 ns multi framing camera X-ray camera which projects the plasma image using four different slit wire pinhole images and six pinhole images, each aperture being filtered differently. The temporal evolution of the emission of each discharge is followed using several silicon PIN diodes. The x-ray spectrum is unfolded from the filter and detector response and interpreted using a collisional radiative package. The hot spots are seen to form in a submillimeter pinch stemming from the incident laser focus which has a life time about 20 ns. The hot spots are much shorter events, reaching substantially higher densities, but involve only part of the line density of the pinch column. (author). 4 figs., 8 refs

  7. Space and time resolved observations of hot spots dynamics in a vacuum spark discharge

    Energy Technology Data Exchange (ETDEWEB)

    Chuaqui, H; Favre, M; Saavedra, R; Wyndham, E [Universidad Catolica de Chile, Santiago (Chile). Facultad de Fisica; Choi, P; Dumitrescu-Zoita, C [Ecole Polytechnique, Palaiseau (France). Laboratoire de Physique des Milieux Ionises; Soto, L [Comision Chilena de Energia Nuclear, Santiago (Chile)

    1997-12-31

    Experimental observations of the plasma formations in a vacuum spark discharge are presented. A low power Nd:YAG laser pulse incident onto a titanium cathode initiates the discharge. The evolution of the titanium plasma electron density and temperature is followed both in the visible and the soft X-ray part of the spectrum. The former uses a novel micro holographic interferometric technique permitting a spatial resolution better than 20 {mu}m. The probing beam is a 6 ns frequency doubled Nd:YAG laser. The latter emission is resolved using a number of different methods. The spatial information is derived from a 1 ns multi framing camera X-ray camera which projects the plasma image using four different slit wire pinhole images and six pinhole images, each aperture being filtered differently. The temporal evolution of the emission of each discharge is followed using several silicon PIN diodes. The x-ray spectrum is unfolded from the filter and detector response and interpreted using a collisional radiative package. The hot spots are seen to form in a submillimeter pinch stemming from the incident laser focus which has a life time about 20 ns. The hot spots are much shorter events, reaching substantially higher densities, but involve only part of the line density of the pinch column. (author). 4 figs., 8 refs.

  8. Vectors and submicron precision: redundancy and 3D stacking in silicon pixel detectors

    CERN Document Server

    Heijne, E H M; Wong, W; Idarraga, J; Visser, J; Jakubek, J; Leroy, C; Turecek, D; Visschers, J; Pospisil, S; Ballabriga, R; Vykydal, Z; Vermeulen, J; Plackett, R; Heijne, E H M; Llopart, X; Boltje, D; Campbell, M

    2010-01-01

    Measurements are shown of GeV pions and muons in two 300 mu m thick, Si Medipix pixel detector assemblies that are stacked on top of each other, with a 25 mu m thick brass foil in between. In such a radiation imaging semiconductor matrix with a large number of pixels along the particle trail, one can determine local space vectors for the particle trajectory instead of points. This improves pattern recognition and track reconstruction, especially in a crowded environment. Stacking of sensor planes is essential for resolving directional ambiguities. Signal charge sharing can be employed for measuring positions with submicron precision. In the measurements one notices accompanying `delta' electrons that emerge outside the particle trail, far beyond the boundaries of the 55 mu m pixel cells. The frequency of such corrupted position measurements is similar to one per 2.5mm of traversed Si.

  9. Ion detectors for isotopic measurements

    Energy Technology Data Exchange (ETDEWEB)

    McCormick, A.

    1978-12-15

    Detector development over the past two decades has been such that this is now the least likely part of the mass spectrometry equipment to give rise to the sort of measurement errors to cause concern. It is now possible to choose from a number of different types of device which can provide more or less 100% efficiency in ion beam detection under all conceivable experimental conditions required for isotopic analysis, from measurement of large samples using the traditional Faraday cage to measurement of exceedingly small ion currents by ion counting techniques. There are even methods of distinguishing one type of ionic species from another in the detector, thus improving the accuracy when unwanted isobaric species might otherwise grossly distort the measurement. Notable contributions to detector development for nuclear measurements have been made by Dietz at the Knolls Atomic Power Laboratory, by Barnett at Oak Ridge and by Daly at Atomic Weapons Research Establishment (AWRE), Aldermaston. This paper describes the detection methods which are currently in use at AWRE for isotopic analysis of solid samples for routine applications as well as non-routine applications. Other methods are merely mentioned as a stimulus for discussion.

  10. ATLAS Detector Interface Group

    CERN Multimedia

    Mapelli, L

    Originally organised as a sub-system in the DAQ/EF-1 Prototype Project, the Detector Interface Group (DIG) was an information exchange channel between the Detector systems and the Data Acquisition to provide critical detector information for prototype design and detector integration. After the reorganisation of the Trigger/DAQ Project and of Technical Coordination, the necessity to provide an adequate context for integration of detectors with the Trigger and DAQ lead to organisation of the DIG as one of the activities of Technical Coordination. Such an organisation emphasises the ATLAS wide coordination of the Trigger and DAQ exploitation aspects, which go beyond the domain of the Trigger/DAQ project itself. As part of Technical Coordination, the DIG provides the natural environment for the common work of Trigger/DAQ and detector experts. A DIG forum for a wide discussion of all the detector and Trigger/DAQ integration issues. A more restricted DIG group for the practical organisation and implementation o...

  11. The HERMES recoil detector

    International Nuclear Information System (INIS)

    Airapetian, A.; Belostotski, S.

    2013-02-01

    For the final running period of HERA, a recoil detector was installed at the HERMES experiment to improve measurements of hard exclusive processes in charged-lepton nucleon scattering. Here, deeply virtual Compton scattering is of particular interest as this process provides constraints on generalised parton distributions that give access to the total angular momenta of quarks within the nucleon. The HERMES recoil detector was designed to improve the selection of exclusive events by a direct measurement of the four-momentum of the recoiling particle. It consisted of three components: two layers of double-sided silicon strip sensors inside the HERA beam vacuum, a two-barrel scintillating fibre tracker, and a photon detector. All sub-detectors were located inside a solenoidal magnetic field with an integrated field strength of 1Tm. The recoil detector was installed in late 2005. After the commissioning of all components was finished in September 2006, it operated stably until the end of data taking at HERA end of June 2007. The present paper gives a brief overview of the physics processes of interest and the general detector design. The recoil detector components, their calibration, the momentum reconstruction of charged particles, and the event selection are described in detail. The paper closes with a summary of the performance of the detection system.

  12. Smile detectors correlation

    Science.gov (United States)

    Yuksel, Kivanc; Chang, Xin; Skarbek, Władysław

    2017-08-01

    The novel smile recognition algorithm is presented based on extraction of 68 facial salient points (fp68) using the ensemble of regression trees. The smile detector exploits the Support Vector Machine linear model. It is trained with few hundreds exemplar images by SVM algorithm working in 136 dimensional space. It is shown by the strict statistical data analysis that such geometric detector strongly depends on the geometry of mouth opening area, measured by triangulation of outer lip contour. To this goal two Bayesian detectors were developed and compared with SVM detector. The first uses the mouth area in 2D image, while the second refers to the mouth area in 3D animated face model. The 3D modeling is based on Candide-3 model and it is performed in real time along with three smile detectors and statistics estimators. The mouth area/Bayesian detectors exhibit high correlation with fp68/SVM detector in a range [0:8; 1:0], depending mainly on light conditions and individual features with advantage of 3D technique, especially in hard light conditions.

  13. The HERMES recoil detector

    Energy Technology Data Exchange (ETDEWEB)

    Airapetian, A. [Giessen Univ. (Germany). Physikalisches Inst.; Michigan Univ., Ann Arbor, MI (United States). Randall Laboratory of Physics; Aschenauer, E.C. [DESY, Zeuthen (Germany); Belostotski, S. [B.P. Konstantinov Petersburg Nuclear Physics Insitute, Gatchina (Russian Federation)] [and others; Collaboration: HERMES Recoil Detector Group

    2013-02-15

    For the final running period of HERA, a recoil detector was installed at the HERMES experiment to improve measurements of hard exclusive processes in charged-lepton nucleon scattering. Here, deeply virtual Compton scattering is of particular interest as this process provides constraints on generalised parton distributions that give access to the total angular momenta of quarks within the nucleon. The HERMES recoil detector was designed to improve the selection of exclusive events by a direct measurement of the four-momentum of the recoiling particle. It consisted of three components: two layers of double-sided silicon strip sensors inside the HERA beam vacuum, a two-barrel scintillating fibre tracker, and a photon detector. All sub-detectors were located inside a solenoidal magnetic field with an integrated field strength of 1Tm. The recoil detector was installed in late 2005. After the commissioning of all components was finished in September 2006, it operated stably until the end of data taking at HERA end of June 2007. The present paper gives a brief overview of the physics processes of interest and the general detector design. The recoil detector components, their calibration, the momentum reconstruction of charged particles, and the event selection are described in detail. The paper closes with a summary of the performance of the detection system.

  14. 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.

  15. A New Virtual Point Detector Concept for a HPGe detector

    International Nuclear Information System (INIS)

    Byun, Jong In; Yun, Ju Yong

    2009-01-01

    For last several decades, the radiation measurement and radioactivity analysis techniques using gamma detectors have been well established. Especially , the study about the detection efficiency has been done as an important part of gamma spectrometry. The detection efficiency depends strongly on source-to-detector distance. The detection efficiency with source-to-detector distance can be expressed by a complex function of geometry and physical characteristics of gamma detectors. In order to simplify the relation, a virtual point detector concept was introduced by Notea. Recently, further studies concerning the virtual point detector have been performed. In previous other works the virtual point detector has been considered as a fictitious point existing behind the detector end cap. However the virtual point detector position for the front and side of voluminous detectors might be different due to different effective central axis of them. In order to more accurately define the relation, therefore, we should consider the virtual point detector for the front as well as side and off-center of the detector. The aim of this study is to accurately define the relation between the detection efficiency and source-to-detector distance with the virtual point detector. This paper demonstrates the method to situate the virtual point detectors for a HPGe detector. The new virtual point detector concept was introduced for three area of the detector and its characteristics also were demonstrated by using Monte Carlo Simulation method. We found that the detector has three virtual point detectors except for its rear area. This shows that we should consider the virtual point detectors for each area when applying the concept to radiation measurement. This concept can be applied to the accurate geometric simplification for the detector and radioactive sources.

  16. Detectors - Electronics; Detecteurs - Electronique

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-04-01

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

  17. Layered semiconductor neutron detectors

    Science.gov (United States)

    Mao, Samuel S; Perry, Dale L

    2013-12-10

    Room temperature operating solid state hand held neutron detectors integrate one or more relatively thin layers of a high neutron interaction cross-section element or materials with semiconductor detectors. The high neutron interaction cross-section element (e.g., Gd, B or Li) or materials comprising at least one high neutron interaction cross-section element can be in the form of unstructured layers or micro- or nano-structured arrays. Such architecture provides high efficiency neutron detector devices by capturing substantially more carriers produced from high energy .alpha.-particles or .gamma.-photons generated by neutron interaction.

  18. Lithium germanium detectors reactivation

    International Nuclear Information System (INIS)

    Nicolai, J.A.; Marti, G.V.; Riso, J.M.; Gimenez, C.R.

    1981-01-01

    A convenient method to regenerate the characteristics of damaged Ge(li) detectors, that has been applied in the authors' laboratory, is described. The procedure consists in warming-up the crystal in its cryostat to temperatures between 10 deg C and 30 deg C above room temperature, in order to clean its surface. Subsequent cooling down to liquid nitrogen temperature, followed by one or more clean-up drifting processes, are applied to the crystals. This paper summarizes the results obtained with several detectors; this method was applied successfully to 15 detectors more. (author) [es

  19. The AGILE anticoincidence detector

    International Nuclear Information System (INIS)

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

    2006-01-01

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

  20. Liquid ionizing radiaion detector

    International Nuclear Information System (INIS)

    deGaston, A.N.

    1979-01-01

    A normally nonconducting liquid such as liquid hydrocarbon is encased between a pair of electrodes in an enclosure so that when the liquid is subjected to ionizing radiation, the ion pairs so created measurably increase the conductivity of the fluid. The reduced impedance between the electrodes is detectable with a sensitive ohm-meter and indicates the amount of ionizing radiation. The enclosure, the electrodes and the fluid can be constructed of materials that make the response of the detector suitable for calibrating a large range of radiation energy levels. The detector is especially useful in medical applications where tissue equivalent X ray detectors are desired

  1. Ionization detectors, ch. 3

    International Nuclear Information System (INIS)

    Sevcik, J.

    1976-01-01

    Most measuring devices used in gas chromatography consist of detectors that measure the ionization current. The process is based on the collision of a moving high-energy particle with a target particle that is ionised while an electron is freed. The discussion of the conditions of the collision reaction, the properties of the colliding particles, and the intensity of the applied field point to a unified classification of ionisation detectors. Radioactive sources suitable for use in these detectors are surveyed. The slow-down mechanism, recombination and background current effect are discussed

  2. The Clover detector

    Energy Technology Data Exchange (ETDEWEB)

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

    1992-08-01

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

  3. Fuel rod leak detector

    International Nuclear Information System (INIS)

    Womack, R.E.

    1978-01-01

    A typical embodiment of the invention detects leaking fuel rods by means of a radiation detector that measures the concentration of xenon-133 ( 133 Xe) within each individual rod. A collimated detector that provides signals related to the energy of incident radiation is aligned with one of the ends of a fuel rod. A statistically significant sample of the gamma radiation (γ-rays) that characterize 133 Xe is accumulated through the detector. The data so accumulated indicates the presence of a concentration of 133 Xe appropriate to a sound fuel rod, or a significantly different concentration that reflects a leaking fuel rod

  4. The HOTWAXS detector

    Energy Technology Data Exchange (ETDEWEB)

    Bateman, J.E.; Derbyshire, G.E. [Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0QX (United Kingdom); Diakun, G. [Science and Technology Facilities Council, Daresbury Laboratory, Keckwick Lane, Daresbury, Warrington WA4 4AD (United Kingdom); Duxbury, D.M. [Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0QX (United Kingdom)], E-mail: d.m.duxbury@rl.ac.uk; Fairclough, J.P.A. [Department of Chemistry, University of Sheffield, Brook Hill, Sheffield S3 7HF (United Kingdom); Harvey, I.; Helsby, W.I. [Science and Technology Facilities Council, Daresbury Laboratory, Keckwick Lane, Daresbury, Warrington WA4 4AD (United Kingdom); Lipp, J.D.; Marsh, A.S.; Salisbury, J. [Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0QX (United Kingdom); Sankar, G. [Royal Institution of GB, 21 Albemarle Street, London W1S 4BS (United Kingdom); Spill, E.J.; Stephenson, R. [Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0QX (United Kingdom); Terrill, N.J. [Diamond Light Source LTD, Harwell Science and Innovation Campus, Diamond House, Chilton, Didcot, Oxfordshire OX11 0DE (United Kingdom)

    2007-10-11

    The development and testing of the HOTWAXS position-sensitive X-ray detector for Synchrotron Radiation Sources is described. Funded from a facility development grant, the aim of the project was to produce a high counting rate, parallax-free photon counting detector to be used in the combined studies of X-ray absorption fine structure and X-ray diffraction (XAFS/XRD), and also in the technique of small angle and wide angle X-ray scattering (SAXS/WAXS). The detector system is described together with results of experiments carried out at the Daresbury Laboratory Synchrotron Radiation Source.

  5. The HOTWAXS detector

    International Nuclear Information System (INIS)

    Bateman, J.E.; Derbyshire, G.E.; Diakun, G.; Duxbury, D.M.; Fairclough, J.P.A.; Harvey, I.; Helsby, W.I.; Lipp, J.D.; Marsh, A.S.; Salisbury, J.; Sankar, G.; Spill, E.J.; Stephenson, R.; Terrill, N.J.

    2007-01-01

    The development and testing of the HOTWAXS position-sensitive X-ray detector for Synchrotron Radiation Sources is described. Funded from a facility development grant, the aim of the project was to produce a high counting rate, parallax-free photon counting detector to be used in the combined studies of X-ray absorption fine structure and X-ray diffraction (XAFS/XRD), and also in the technique of small angle and wide angle X-ray scattering (SAXS/WAXS). The detector system is described together with results of experiments carried out at the Daresbury Laboratory Synchrotron Radiation Source

  6. Semiconductor ionizino. radiation detectors

    International Nuclear Information System (INIS)

    1982-01-01

    Spectrometric semiconductor detectors of ionizing radiation with the electron-hole junction, based on silicon and germanium are presented. The following parameters are given for the individual types of germanium detectors: energy range of detected radiation, energy resolution given as full width at half maximum (FWHM) and full width at one tenth of maximum (FWTM) for 57 Co and 60 Co, detection sensitivity, optimal voltage, and electric capacitance at optimal voltage. For silicon detectors the value of FWHM for 239 Pu is given, the sensitive area and the depth of the sensitive area. (E.S.)

  7. Microfluidic Scintillation Detectors

    CERN Multimedia

    Microfluidic scintillation detectors are devices of recent introduction for the detection of high energy particles, developed within the EP-DT group at CERN. Most of the interest for such technology comes from the use of liquid scintillators, which entails the possibility of changing the active material in the detector, leading to an increased radiation resistance. This feature, together with the high spatial resolution and low thickness deriving from the microfabrication techniques used to manufacture such devices, is desirable not only in instrumentation for high energy physics experiments but also in medical detectors such as beam monitors for hadron therapy.

  8. MCNP simulations of a new time-resolved Compton scattering imaging technique

    International Nuclear Information System (INIS)

    Ilan, Y.

    2004-01-01

    Medical images of human tissue can be produced using Computed Tomography (CT), Positron Emission Tomography (PET), Ultrasound or Magnetic Resonance Imaging (MRI). In all of the above techniques, in order to get a three-dimensional (3D) image, one has to rotate or move the source, the detectors or the scanned target. This procedure is complicated, time consuming and increases the cost and weight of the scanning equipment. Time resolved optical tomography has been suggested as an alternative to the above conventional methods. This technique implies near infrared light (NIR) and fast time-resolved detectors to obtain a 3D image of the scanned target. However, due to the limited penetration of the NIR light in the tissue, the application of this technique is limited to soft tissue like a female breast or a premature infant brain

  9. A gamma-ray tracking detector for molecular imaging

    International Nuclear Information System (INIS)

    Hall, C.J.; Lewis, R.A.; Helsby, W.I.; Nolan, P.; Boston, A.

    2003-01-01

    A design for a gamma-ray detector for molecular imaging is presented. The system is based on solid-state strip detector technology. The advantages of position sensitivity coupled with fine spectral resolution are exploited to produce a tracking detector for use with a variety of isotopes in nuclear medicine. Current design concepts employ both silicon and germanium layers to provide an energy range from 60 keV to >1 MeV. This allows a reference X-ray image to be collected simultaneously with the gamma-ray image providing accurate anatomical registration. The tracking ability of the gamma-ray detector allows ambiguities in the data set to be resolved which would otherwise cause events to be rejected in standard non-tracking system. Efficiency improvements that high solid angle coverage and the use of a higher proportion of events make time resolved imaging and multi-isotope work possible. A modular detector system, designed for viewing small animals has been accepted for funding

  10. On Recall Rate of Interest Point Detectors

    DEFF Research Database (Denmark)

    Aanæs, Henrik; Dahl, Anders Lindbjerg; Pedersen, Kim Steenstrup

    2010-01-01

    in relation to the number of interest points, the recall rate as a function of camera position and light variation, and the sensitivity relative to model parameter change. The overall conclusion is that the Harris corner detector has a very high recall rate, but is sensitive to change in scale. The Hessian......In this paper we provide a method for evaluating interest point detectors independently of image descriptors. This is possible because we have compiled a unique data set enabling us to determine if common interest points are found. The data contains 60 scenes of a wide range of object types......, and for each scene we have 119 precisely located camera positions obtained from a camera mounted on an industrial robot arm. The scene surfaces have been scanned using structured light, providing precise 3D ground truth. We have investigated a number of the most popular interest point detectors. This is done...

  11. Novel silicon stripixel detector: concept, simulation, design, and fabrication

    International Nuclear Information System (INIS)

    Li, Z.

    2004-01-01

    A novel detector concept has been developed in this work that has the necessary properties to provide two-dimensional (2-D) position sensitivity with a moderate number of readout electronic channels and single-sided detector fabrication process. The concept is based on interleaved pixel electrodes arranged in a projective X-Y readout, which makes possible position encoding with minimum number of channels. In further discussions, we refer to this concept as 'stripixel' detector, as it combines the 2-D position resolution of a pixel electrode geometry with the simplicity of the projective readout of a double-sided strip detector. For DC coupled detectors with large pitches (>20 μm), individual pixels are divided into X- and Y-cell that can be interleaved by many different schemes that ensure the charge sharing between them. This type of stripixel detectors is called interleaved stripixel detectors. When the detector pitch goes down (<20 μm), the X and Y-pixel may not have to be interleaved, and they can be connected in an alternating way to X-Y strip readout. This type of stripixel detectors is called alternating stripixel detectors (ASD). For ASD, a position resolution better than 1 μm in two dimensions can be achieved by determining the centroid of the charge collected on pixel electrodes with a granularity in the range of 5-6 μm. For AC coupled detectors, no interleaving scheme may be needed, and there may be no limit on the pitch size, i.e. it may go from pitches in the order of microns, to hundreds of microns or even mm's. This electrode granularity does not pose difficult demands on the lithography and the fabrication technology. This novel detector concept can be applied to any semiconductor detectors/sensors, such as Si, Ge, GaAs, SiC, diamond, etc

  12. Dijet angular distributions in direct and resolved photoproduction at HERA

    International Nuclear Information System (INIS)

    Derrick, M.; Krakauer, D.; Magill, S.

    1996-05-01

    Jet photoproduction, where the two highest transverse energy (E T jet ) jets have E T jet above 6 GeV and a jet-jet invariant mass above 23 GeV, has been studied with the ZEUS detector at the HERA ep collider. Resolved and direct photoproduction samples have been separated. The cross section as a function of the angle between the jet-jet axis and the beam direction in the dijet rest frame has been measured for the two samples. The measured angular distributions differ markedly from each other. They agree with the predictions of QCD calculations, where the different angular distributions reflect the different spins of the quark and gluon exchanged in the hard subprocess. (orig.)

  13. Modeling of clover detector in addback mode

    Science.gov (United States)

    Kshetri, R.

    2012-07-01

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

  14. Modeling of clover detector in addback mode

    International Nuclear Information System (INIS)

    Kshetri, R

    2012-01-01

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

  15. Preliminary A ampersand PCT multiple detector design

    International Nuclear Information System (INIS)

    Roberson, G.P.; Martz, H.E.; Camp, D.C.; Decman, D.J.; Johansson, E.M.

    1997-01-01

    The next generation, multi-detector active and passive computed tomography (A ampersand PCT) scanner will be optimized for speed and accuracy. At the Lawrence Livermore National Lab (LLNL) we have demonstrated the trade-offs between different A ampersand PCT design parameters that affect the speed and quality of the assay results. These fundamental parameters govern the optimum system design. Although the multi-detector scanner design has priority put on speed to increase waste drum throughput, higher speed should not compromise assay accuracy. One way to increase the speed of the A ampersand PCT technology is to use multiple detectors. This yields a linear speedup by a factor approximately equal to the number of detectors used without a compromise in system accuracy. There are many different design scenarios that can be developed using multiple detectors. Here we describe four different scenarios and discuss the trade-offs between them. Also, some considerations are given in this design description for the implementation of a multiple detector technology in a field- deployable mobile trailer system

  16. Ionizing radiation detector using multimode optical fibers

    International Nuclear Information System (INIS)

    Suter, J.J.; Poret, J.C.; Rosen, M.; Rifkind, J.M.

    1993-01-01

    An optical ionizing radiation detector, based on the attenuation of 850-nm light in 50/125-μm multimode fibers, is described. The detector is especially well suited for application on spacecraft because of its small design. The detection element consists of a section of coiled fibers that has been designed to strip higher-order optical modes. Cylindrical radiation shields with atomic numbers ranging from Z = 13 (aluminum too) Z = 82 (lead) were placed around the ionizing radiation detector so that the effectiveness of the detector could be measured. By exposing the shields and the detector to 1.25-MeV cobalt 60 radiation, the mass attenuation coefficients of the shields were measured. The detector is based on the phenomenon that radiation creates optical color centers in glass fibers. Electron spin resonance spectroscopy performed on the 50/125-μm fibers showed the presence of germanium oxide and phosphorus-based color centers. The intensity of these centers is directly related to the accumulated gamma radiation

  17. Training detector as simulator of alpha detector

    International Nuclear Information System (INIS)

    Tirosh, D.; Duvniz, E.; Assido, H.; Barak, D.; Paran, J.

    1997-01-01

    Alpha contamination is a common phenomena in radiation research laboratories and other sites. Training staff to properly detect and control alpha contamination, present special problems. In order to train health physics personnel, while using alpha sources, both the trainers and the trainees are inevitably exposed to alpha contamination. This fact of course, comes in conflict with safety principles. In order to overcome these difficulties, a training detector was developed, built and successfully tested. (authors)

  18. Multi electrode semiconductors detectors

    CERN Document Server

    Amendolia, S R; Bertolucci, Ennio; Bosisio, L; Bradaschia, C; Budinich, M; Fidecaro, F; Foà, L; Focardi, E; Giazotto, A; Giorgi, M A; Marrocchesi, P S; Menzione, A; Ristori, L; Rolandi, Luigi; Scribano, A; Stefanini, A; Vincelli, M L

    1981-01-01

    Detectors with very high space resolution have been built in this laboratory and tested at CERN in order to investigate their possible use in high energy physics experiments. These detectors consist of thin layers of silicon crystals acting as ionization chambers. Thin electrodes, structured in strips or in more fancy shapes are applied to their surfaces by metal coating. The space resolution which could be reached is of the order of a few microns. An interesting feature of these solid state detectors is that they can work under very high or low external pressure or at very low temperature. The use of these detectors would strongly reduce the dimensions and the cost of high energy experiments. (3 refs).

  19. Multi electrode semiconductor detectors

    International Nuclear Information System (INIS)

    Amendolia, S.R.; Batignani, G.; Bertolucci, E.; Bosisio, L.; Budinich, M.; Bradaschia, C.; Fidecaro, F.; Foa, L.; Focardi, E.; Giazotto, A.; Giorgi, M.A.; Marrocchesi, P.S.; Menzione, A.; Ristori, L.; Rolandi, L.; Scribano, A.; Stefanini, A.; Vincelli, M.L.

    1981-01-01

    Detectors with very high space resolution have been built in the laboratory and tested at CERN in order to investigate their possible use in high energy physics experiments. These detectors consist of thin layers of silicon crystals acting as ionization chambers. Thin electrodes, structured in strips or in more fancy shapes are applied to their surfaces by metal coating. The space resolution which could be reached is of the order of a few microns. An interesting feature of these solid state detectors is that they can work under very high or low external pressure or at very low temperature. The use of these detectors would strongly reduce the dimensions and the cost of high energy experiments. (Auth.)

  20. Inverter ratio failure detector

    Science.gov (United States)

    Wagner, A. P.; Ebersole, T. J.; Andrews, R. E. (Inventor)

    1974-01-01

    A failure detector which detects the failure of a dc to ac inverter is disclosed. The inverter under failureless conditions is characterized by a known linear relationship of its input and output voltages and by a known linear relationship of its input and output currents. The detector includes circuitry which is responsive to the detector's input and output voltages and which provides a failure-indicating signal only when the monitored output voltage is less by a selected factor, than the expected output voltage for the monitored input voltage, based on the known voltages' relationship. Similarly, the detector includes circuitry which is responsive to the input and output currents and provides a failure-indicating signal only when the input current exceeds by a selected factor the expected input current for the monitored output current based on the known currents' relationship.

  1. Sensitive detectors in HPLC

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

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

  2. OPAL detector electromagnetic calorimeter

    CERN Multimedia

    1988-01-01

    Half of the electromagnetic calorimeter of the OPAL detector is seen in this photo. This calorimeter consists of 4720 blocks of lead glass. It was used to detect and measure the energy of photons, electrons and positrons by absorbing them.

  3. A synchrotron radiation camera and data acquisition system for time resolved x-ray scattering studies

    International Nuclear Information System (INIS)

    Bordas, J.; Koch, M.H.J.; Clout, P.N.; Dorrington, E.; Boulin, C.; Gabriel, A.

    1980-01-01

    Until recently, time resolved measurements of x-ray scattering patterns have not been feasible because laboratory x-ray sources were too weak and detectors unavailable. Recent developments in both these fields have changed the situation, and it is now possible to follow changes in x-ray scattering patterns with a time resolution of a few ms. The apparatus used to achieve this is described and some examples from recent biological experiments are given. (author)

  4. Detectors, sampling, shielding, and electronics for positron emission tomography

    International Nuclear Information System (INIS)

    Derenzo, S.E.

    1981-08-01

    A brief discussion of the important design elements for positron emission tomographs is presented. The conclusions are that the instrumentation can be improved by the use of larger numbers of small, efficient detectors closely packed in many rings, the development of new detector materials, and novel electronic designs to reduce the deadtime and increase maximum event rates

  5. Precision tracking with a single gaseous pixel detector

    NARCIS (Netherlands)

    Tsigaridas, S.; van Bakel, N.; Bilevych, Y.; Gromov, V.; Hartjes, F.; Hessey, N.P.; de Jong, P.; Kluit, R.

    2015-01-01

    The importance of micro-pattern gaseous detectors has grown over the past few years after successful usage in a large number of applications in physics experiments and medicine. We develop gaseous pixel detectors using micromegas-based amplification structures on top of CMOS pixel readout chips.

  6. Detector Control System for the ATLAS Forward Proton detector

    CERN Document Server

    Czekierda, Sabina; The ATLAS collaboration

    2017-01-01

    The ATLAS Forward Proton (AFP) is a forward detector using a Roman Pot technique, recently installed in the LHC tunnel. It is aiming at registering protons that were diffractively or electromagnetically scattered in soft and hard processes. Infrastructure of the detector consists of hardware placed both in the tunnel and in the control room USA15 (about 330 meters from the Roman Pots). AFP detector, like the other detectors of the ATLAS experiment, uses the Detector Control System (DCS) to supervise the detector and to ensure its safe and coherent operation, since the incorrect detector performance may influence the physics results. The DCS continuously monitors the detector parameters, subset of which is stored in data bases. Crucial parameters are guarded by alarm system. A detector representation as a hierarchical tree-like structure of well-defined subsystems built with the use of the Finite State Machine (FSM) toolkit allows for overall detector operation and visualization. Every node in the hierarchy is...

  7. New detector techniques

    CERN Document Server

    Iarocci, Enzo

    1994-03-14

    The intense R&D effort being carried out in view of LHC has given rise in a relatively short time to a wide spectrum of new detector concepts and technologies. Subject of the lectures will be some of the most interesting new ideas and developments, in the field of noble liquid, crystal and scintillating fiber trackers. The emphasis will be on the basic aspects of detector operation.

  8. The Micro Wire Detector

    International Nuclear Information System (INIS)

    Adeva, B.; Gomez, F.; Pazos, A.; Pfau, R.; Plo, M.; Rodriguez, J.M.; Vazquez, P.; Labbe, J.C.

    1999-01-01

    We present the performance of a new proportional gas detector. Its geometry consists of a cathode plane with 70x70 μm 2 apertures, crossed by 25 μm anode strips to which it is attached by 50 μm kapton spacers. In the region where the avalanche takes place, the anode strips are suspended in the gas mixture as in a standard wire chamber. This detector exhibits high rate capability and large gains, introducing very little material. (author)

  9. Calibration of germanium detectors

    International Nuclear Information System (INIS)

    Bjurman, B.; Erlandsson, B.

    1985-01-01

    This paper describes problems concerning the calibration of germanium detectors for the measurement of gamma-radiation from environmental samples. It also contains a brief description of some ways of reducing the uncertainties concerning the activity determination. These uncertainties have many sources, such as counting statistics, full energy peak efficiency determination, density correction and radionuclide specific-coincidence effects, when environmental samples are investigated at close source-to-detector distances

  10. Liquid xenon detector engineering

    International Nuclear Information System (INIS)

    Chen, E.; Chen, M.; Gaudreau, M.P.J.; Montgomery, D.B.; Pelly, J.D.; Shotkin, S.; Sullivan, J.D.; Sumorok, K.; Yan, X.; Zhang, X.; Lebedenko, V.

    1991-01-01

    The design, engineering constraints and R and D status of a 15 m 3 precision liquid xenon, electromagnetic calorimeter for the Superconducting Super Collider are discussed in this paper. Several prototype liquid xenon detectors have been built, and preliminary results are described. The design of a conical 7 cell by 7 cell detector capable of measuring fully contained high energy electron showers is described in detail

  11. FERMILAB: Collider detectors -2

    International Nuclear Information System (INIS)

    Anon.

    1993-01-01

    Last month's edition (April, page 12) included a status report on data collection and preliminary physics results from the 'newcomer' DO detector at Fermilab's Tevatron proton-antiproton collider. This time the spotlight falls in the Veteran' CDF detector, in action since 1985 and meanwhile significantly upgraded. Meanwhile the Tevatron collider continues to improve, with record collision rates

  12. Microsonic detector (MSD)

    International Nuclear Information System (INIS)

    Bober, J.T.; Haridas, P.; Oh, S.H.; Pless, I.A.; Stoughton, T.B.

    1983-01-01

    The microsonic detector (MSD) has good spatial resolution, moderate flux capacity, moderate event rate, and small volume. The MSD is a super clean bubble chamber driven at 10-50 KHz. It would be used in experiments as a vertex detector to detect short lived particles. Its characteristics--active volume, density, absorption length, radiation length, and spatial resolution--are given. The setup is schematicized, and a photograph of a 130 MeV/C photon bremsstrahlung beam is given

  13. Resolvability of regional density structure

    Science.gov (United States)

    Plonka, A.; Fichtner, A.

    2016-12-01

    Lateral density variations are the source of mass transport in the Earth at all scales, acting as drivers of convectivemotion. However, the density structure of the Earth remains largely unknown since classic seismic observables and gravityprovide only weak constraints with strong trade-offs. Current density models are therefore often based on velocity scaling,making strong assumptions on the origin of structural heterogeneities, which may not necessarily be correct. Our goal is to assessif 3D density structure may be resolvable with emerging full-waveform inversion techniques. We have previously quantified the impact of regional-scale crustal density structure on seismic waveforms with the conclusion that reasonably sized density variations within thecrust can leave a strong imprint on both travel times and amplitudes, and, while this can produce significant biases in velocity and Q estimates, the seismic waveform inversion for density may become feasible. In this study we performprincipal component analyses of sensitivity kernels for P velocity, S velocity, and density. This is intended to establish theextent to which these kernels are linearly independent, i.e. the extent to which the different parameters may be constrainedindependently. Since the density imprint we observe is not exclusively linked to travel times and amplitudes of specific phases,we consider waveform differences between complete seismograms. We test the method using a known smooth model of the crust and seismograms with clear Love and Rayleigh waves, showing that - as expected - the first principal kernel maximizes sensitivity to SH and SV velocity structure, respectively, and that the leakage between S velocity, P velocity and density parameter spaces is minimal in the chosen setup. Next, we apply the method to data from 81 events around the Iberian Penninsula, registered in total by 492 stations. The objective is to find a principal kernel which would maximize the sensitivity to density

  14. Proposal for a CLEO precision vertex detector

    International Nuclear Information System (INIS)

    1991-01-01

    Fermilab experiment E691 and CERN experiment NA32 have demonstrated the enormous power of precision vertexing for studying heavy quark physics. Nearly all collider experiments now have or are installing precision vertex detectors. This is a proposal for a precision vertex detector for CLEO, which will be the pre-eminent heavy quark experiment for at least the next 5 years. The purpose of a precision vertex detector for CLEO is to enhance the capabilities for isolating B, charm, and tau decays and to make it possible to measure the decay time. The precision vertex detector will also significantly improve strange particle identification and help with the tracking. The installation and use of this detector at CLEO is an important step in developing a vertex detector for an asymmetric B factory and therefore in observing CP violation in B decays. The CLEO environment imposes a number of unique conditions and challenges. The machine will be operating near the γ (4S) in energy. This means that B's are produced with a very small velocity and travel a distance about 1/2 that of the expected vertex position resolution. As a consequence B decay time information will not be useful for most physics. On the other hand, the charm products of B decays have a higher velocity. For the long lived D + in particular, vertex information can be used to isolate the charm particle on an event-by-event basis. This helps significantly in reconstructing B's. The vertex resolution for D's from B's is limited by multiple Coulomb scattering of the necessarily rather low momentum tracks. As a consequence it is essential to minimize the material, as measured in radiation lengths, in the beam pip and the vertex detector itself. It is also essential to build the beam pipe and detector with the smallest possible radius

  15. Protecting detectors in ALICE

    International Nuclear Information System (INIS)

    Lechman, M.; Augustinus, A.; Chochula, P.; Di Mauro, A.; Stig Jirden, L.; Rosinsky, P.; Schindler, H.; Cataldo, G. de; Pinazza, O.; Kurepin, A.; Moreno, A.

    2012-01-01

    ALICE (A Large Ion Collider Experiment) is one of the big LHC (Large Hadron Collider) experiments at CERN in Geneva. It is composed of many sophisticated and complex detectors mounted very compactly around the beam pipe. Each detector is a unique masterpiece of design, engineering and construction and any damage to it could stop the experiment for months or even for years. It is therefore essential that the detectors are protected from any danger and this is one very important role of the Detector Control System (DCS). One of the main dangers for the detectors is the particle beam itself. Since the detectors are designed to be extremely sensitive to particles they are also vulnerable to any excess of beam conditions provided by the LHC accelerator. The beam protection consists of a combination of hardware interlocks and control software and this paper will describe how this is implemented and handled in ALICE. Tools have also been developed to support operators and shift leaders in the decision making related to beam safety. The gained experiences and conclusions from the individual safety projects are also presented. (authors)

  16. Radiation detectors for reactors

    International Nuclear Information System (INIS)

    Balagi, V.

    2005-01-01

    Detection and measurement of radiation plays a vital role in nuclear reactors from the point of view of control and safety, personnel protection and process control applications. Various types of radiation are measured over a wide range of intensity. Consequently a variety of detectors find use in nuclear reactors. Some of these devices have been developed in Electronics Division. They include gas-filled detectors such as 10 B-lined proportional counters and chambers, fission detectors and BF 3 counters are used for the measurement of neutron flux both for reactor control and safety, process control as well as health physics instrumentation. In-core neutron flux instrumentation employs the use detectors such as miniature fission detectors and self-powered detectors. In this development effort, several indigenous materials, technologies and innovations have been employed to suit the specific requirement of nuclear reactor applications. This has particular significance in view of the fact that several new types of reactors such as P-4, PWR and AHWR critical facilities, FBTR, PFBR as well as the refurbishment of old units like CIRUS are being developed. The development work has sought to overcome some difficulties associated with the non-availability of isotopically enriched neutron-sensing materials, achieving all-welded construction etc. The present paper describes some of these innovations and performance results. (author)

  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. Resolving Standard Essential Patents Issues through Competition Law (Japanese)

    OpenAIRE

    KAWAHAMA Noboru

    2015-01-01

    The number of disputes relating to standard essential patents (SEPs), in which patent holders submit statements to commit to granting licenses on a fair, reasonable and non-discriminatory (FRAND) basis, have increased. The exercise of SEPs tends to cause problems such as hold-ups and royalty stacking and needs to be constrained somehow. Despite wide recognition of the need to address these problems, devising measures to resolve the issue has not been an easy task since various laws and princi...

  19. Basic Radiation Detectors. Chapter 6

    Energy Technology Data Exchange (ETDEWEB)

    Van Eijk, C. W.E. [Faculty of Applied Sciences, Delft University of Technology, Delft (Netherlands)

    2014-12-15

    Radiation detectors are of paramount importance in nuclear medicine. The detectors provide a wide range of information including the radiation dose of a laboratory worker and the positron emission tomography (PET) image of a patient. Consequently, detectors with strongly differing specifications are used. In this chapter, general aspects of detectors are discussed.

  20. Frontier detectors for frontier physics

    International Nuclear Information System (INIS)

    Cervelli, F.; Scribano, A.

    1984-01-01

    These proceedings contain the articles presented at the named meeting. These concern developments of radiation detectors and counting techniques in high energy physics. Especially considered are tracking detectors, calorimeters, time projection chambers, detectors for rare events, solid state detectors, particle identification, and optical readout systems. See hints under the relevant topics. (HSI)

  1. The ALICE forward multiplicity detector

    DEFF Research Database (Denmark)

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

    2007-01-01

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

  2. Progress in semiconductor drift detectors

    International Nuclear Information System (INIS)

    Rehak, P.; Walton, J.; Gatti, E.

    1985-01-01

    Progress in testing semiconductor drift detectors is reported. Generally better position and energy resolutions were obtained than resolutions published previously. The improvement is mostly due to new electronics better matched to different detectors. It is shown that semiconductor drift detectors are becoming versatile and reliable detectors for position and energy measurements

  3. Imposing resolved turbulence in CFD simulations

    DEFF Research Database (Denmark)

    Gilling, L.; Sørensen, Niels N.

    2011-01-01

    In large‐eddy simulations, the inflow velocity field should contain resolved turbulence. This paper describes and analyzes two methods for imposing resolved turbulence in the interior of the domain in Computational Fluid Dynamics simulations. The intended application of the methods is to impose...

  4. Detectors on the drawing board

    CERN Document Server

    Katarina Anthony

    2011-01-01

    Linear collider detector developers inside and outside CERN are tackling the next generation of detector technology. While their focus has centred on high-energy linear collider detectors, their innovative concepts and designs will be applicable to any future detector.   A simulated event display in one of the new generation detectors. “While the LHC experiments remain the pinnacle of detector technology, you may be surprised to realise that the design and expertise behind them is well over 10 years old,” says Lucie Linssen, CERN’s Linear Collider Detector (LCD) project manager whose group is pushing the envelope of detector design. “The next generation of detectors will have to surpass the achievements of the LHC experiments. It’s not an easy task but, by observing detectors currently in operation and exploiting a decade’s worth of technological advancements, we’ve made meaningful progress.” The LCD team is curr...

  5. Time-resolved Laue diffraction from protein crystals: Instrumental considerations

    International Nuclear Information System (INIS)

    Bilderback, D.H.; Cornell Univ., Ithaca, NY; Moffat, K.; Szebenyi, D.M.E.

    1984-01-01

    A serious limitation of macromolecular crystallography has been its inability to determine changes in structure on a biochemical time scale of milliseconds or less. Recently, we have shown that X-ray exposures on single crystals of macromolecules may be obtained in the millisecond time range through the use of intense, polychromatic radiation with Δlambda/lambda approx.= 0.2 derived from the Cornell High Energy Synchrotron Source, CHESS. Such radiation falling on a stationary crystal yields a Laue diffraction pattern, in which almost all Laue reflections arise from a unique set of Miller indices and where their intensities are automatically integrated over wavelength. This Laue technique requires wide band pass optics, which may be obtained by a combination of reflection and transmission mirrors, filters or layered synthetic microstructures. Time-resolved macromolecular crystallography may be achieved by several data collection schemes: 'one-shot' recording coupled to a simple streak camera, repetitive sample perturbation coupled to a detector with temporal resolution and repetitive perturbation which uses the synchrotron pulses for stroboscopic triggering and detection. These schemes are appropriate for different time scales, roughly the milli-, micro- and nanosecond regimes. It appears that time-resolved crystallography is entirely feasible, with an ultimate time resolution limited only by the length of a synchrotron light pulse, some 150 ps at CHESS. (orig.)

  6. Ionization smoke detectors - the high-voltage issues

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    Production of high-voltage ionization smoke detectors ceased in 1978 following the development of lower voltage models which used much smaller amounts of radioactive material. Despite this fact, thousands of high-voltage detectors are still in use today in many large UK companies. The major users argue that there is no reason to stop using their detectors if they are still fit for their purpose - many could last for another 15 to 20 years if properly maintained. But pressure has been mounting on businesses to replace all their high-voltage detectors with new low-voltage models within the next couple of years. This could place a huge financial burden on the companies concerned, with costs possibly running into millions of pounds. Traditionally, the major detector installers offered cleaning and maintenance services for high-voltage detectors to their customers but these have now been withdrawn. The installers give no clear reasons for this decision except that the detectors are outmoded and should be disposed of as soon as possible. Most users would agree that conversion to low-voltage types is inevitable but their main worry is the financial strain of replacing all their detectors - and associated equipment - in one go. They would prefer to phase out their high-voltage detectors in stages over a number of years to spread the costs of conversion. The problems of maintenance is discussed. A dual voltage fire alarm panel which allows the high-voltage detectors to be phased out is mentioned. (Author)

  7. 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

  8. Performance of fine grained photon position detector using proportional tubes

    International Nuclear Information System (INIS)

    Artemiev, V.; Galaktionov, Y.; Gordeev, A.; Gorodkov, Y.; Kamishkov, Y.; Lubimov, V.; Plyaskin, V.; Pojidaev, V.; Shevchenko, V.; Shumilov, E.; Bamberger, A.; Fuchs, M.; Giesen, G.; Heck, W.; Ludwig, J.; Marx, R.; Mocken, T.; Runge, K.; Skodzek, E.; Weber, H.C.; Weltin, A.; Wuelker, M.

    1984-01-01

    As part of the NA24 experiment at the CERN-SPS a photon position detector serves to separate direct photons from abundantly produced π 0 decay photons: electromagnetic showers are measured with an energy- and position-resolution sufficiently good to give a two-gamma resolving power of 1.2 cm. The shower detector covers 3 x 3 m 2 and consists of 12 layers of triangular proportional tubes (7.73 mm pitch) sandwiched with lead (altogether 9.6 X 0 ). For eight layers the analog information is provided by an ADC system. Ambiguities are resolved by the digital information of four additional layers inclined by 45 0 . Prototypes were built in order to test gas mixtures and electronics. The electromagnetic shower development in the PPD and the prototypes are reproduced by Monte Carlo calculations. The homogeneity of the PPD has been checked by calibration measurements. (orig.)

  9. Resolvent-based feedback control for turbulent friction drag reduction

    Science.gov (United States)

    Kawagoe, Aika; Nakashima, Satoshi; Luhar, Mitul; Fukagata, Koji

    2017-11-01

    Suboptimal control for turbulent friction drag reduction has been studied extensively. Nakashima et al. (accepted) extended resolvent analysis to suboptimal control, and for the control where the streamwise wall shear stress is used as an input (Case ST), they revealed the control effect across spectral space is mixed: there are regions of drag increase as well as reduction. This suggests that control performance may be improved if the control is applied for selective wavelengths, or if a new law is designed to suppress the spectral region leading to drag increase. In the present study, we first assess the effect of suboptimal control for selective wavelengths via DNS. The friction Reynolds number is set at 180. For Case ST, resolvent analysis predicts drag reduction at long streamwise wavelengths. DNS with control applied only for this spectral region, however, did not result in drag reduction. Then, we seek an effective control law using resolvent analysis and propose a new law. DNS results for this law are consistent with predictions from resolvent analysis, and about 10% drag reduction is attained. Further, we discuss how this law reduces the drag from a dynamical and theoretical point of view. This work was supported through Grant-in-Aid for Scientic Research (C) (No. 25420129) by Japan Society for the Promotion of Science (JSPS).

  10. Small Angle X-Ray Scattering Detector

    Energy Technology Data Exchange (ETDEWEB)

    Hessler, Jan P.

    2004-06-15

    A detector for time-resolved small-angle x-ray scattering includes a nearly constant diameter, evacuated linear tube having an end plate detector with a first fluorescent screen and concentric rings of first fiber optic bundles for low angle scattering detection and an annular detector having a second fluorescent screen and second fiber optic bundles concentrically disposed about the tube for higher angle scattering detection. With the scattering source, i.e., the specimen under investigation, located outside of the evacuated tube on the tube's longitudinal axis, scattered x-rays are detected by the fiber optic bundles, to each of which is coupled a respective photodetector, to provide a measurement resolution, i.e., dq/q, where q is the momentum transferred from an incident x-ray to an x-ray scattering specimen, of 2% over two (2) orders of magnitude in reciprocal space, i.e., qmax/qmin approx=lO0.

  11. Pure sources and efficient detectors for optical quantum information processing

    Science.gov (United States)

    Zielnicki, Kevin

    optimizing the detection efficiency of visible light photon counters (VLPCs), a single-photon detection technology that is also capable of resolving photon number states. We report a record-breaking quantum efficiency of 91 +/- 3% observed with our detection system. Both sources and detectors are independently interesting physical systems worthy of study, but together they promise to enable entire new classes and applications of information based on quantum mechanics.

  12. High-speed readout of high-Z pixel detectors with the LAMBDA detector

    International Nuclear Information System (INIS)

    Pennicard, D.; Smoljanin, S.; Sheviakov, I.; Xia, Q.; Rothkirch, A.; Yu, Y.; Struth, B.; Hirsemann, H.; Graafsma, H.

    2014-01-01

    High-frame-rate X-ray pixel detectors make it possible to perform time-resolved experiments at synchrotron beamlines, and to make better use of these sources by shortening experiment times. LAMBDA is a photon-counting hybrid pixel detector based on the Medipix3 chip, designed to combine a small pixel size of 55 μm, a large tileable module design, high speed, and compatibility with ''high-Z'' sensors for hard X-ray detection. This technical paper focuses on LAMBDA's high-speed-readout functionality, which allows a frame rate of 2000 frames per second with no deadtime between successive images. This takes advantage of the Medipix3 chip's ''continuous read-write'' function and highly parallelised readout. The readout electronics serialise this data and send it back to a server PC over two 10 Gigabit Ethernet links. The server PC controls the detector and receives, processes and stores the data using software designed for the Tango control system. As a demonstration of high-speed readout of a high-Z sensor, a GaAs LAMBDA detector was used to make a high-speed X-ray video of a computer fan

  13. Performance characteristics needed for protein crystal diffraction x-ray detectors

    International Nuclear Information System (INIS)

    Westbrook, E. M.

    1999-01-01

    During the 1990's, macromolecular crystallography became progressively more dependent on synchrotrons X-ray sources for diffraction data collection. Detectors of this diffraction data at synchrotrons beamlines have evolved over the decade, from film to image phosphor plates, and then to CCD systems. These changes have been driven by the data quality and quantity improvements each newer detector technology provided. The improvements have been significant. It is likely that newer detector technologies will be adopted at synchrotron beamlines for crystallographic diffraction data collection in the future, but these technologies will have to compete with existing CCD detector systems which are already excellent and are getting incrementally better in terms of size, speed, efficiency, and resolving power. Detector development for this application at synchrotrons must concentrate on making systems which are bigger and faster than CCDs and which can capture weak data more efficiently. And there is a need for excellent detectors which are less expensive than CCD systems

  14. Detectors for proton counting. Si-APD and scintillation detectors

    International Nuclear Information System (INIS)

    Kishimoto, Shunji

    2008-01-01

    Increased intensity of synchrotron radiation requests users to prepare photon pulse detectors having higher counting rates. As detectors for photon counting, silicon-avalanche photodiode (Si-APD) and scintillation detectors were chosen for the fifth series of detectors. Principle of photon detection by pulse and need of amplification function of the detector were described. Structure and working principle, high counting rate measurement system, bunch of electrons vs. counting rate, application example of NMR time spectroscopy measurement and comments for users were described for the Si-APD detector. Structure of scintillator and photomultiplier tube, characteristics of scintillator and performance of detector were shown for the NaI detector. Future development of photon pulse detectors was discussed. (T. Tanaka)

  15. A 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

  16. NEUTRON SPECTRUM MEASUREMENTS USING MULTIPLE THRESHOLD DETECTORS

    Energy Technology Data Exchange (ETDEWEB)

    Gerken, William W.; Duffey, Dick

    1963-11-15

    From American Nuclear Society Meeting, New York, Nov. 1963. The use of threshold detectors, which simultaneously undergo reactions with thermal neutrons and two or more fast neutron threshold reactions, was applied to measurements of the neutron spectrum in a reactor. A number of different materials were irradiated to determine the most practical ones for use as multiple threshold detectors. These results, as well as counting techniques and corrections, are presented. Some materials used include aluminum, alloys of Al -Ni, aluminum-- nickel oxides, and magesium orthophosphates. (auth)

  17. Large-Area Liquid Scintillation Detector Slab

    International Nuclear Information System (INIS)

    Crouch, M. F.; Gurr, H. S.; Hruschka, A. A.; Jenkins, T. L.; Kropp, W.; Reines, F.; Sobel, H.; Hruschka, A. A.

    1966-01-01

    A low-cost detector 18' x 2' x 5' has been developed for an underground cosmic ray neutrino experiment. The liquid employed is a high-clarity mineral oil-based mixture, and light is guided to the ends of the detector by total internal reflection at the surface of the Lucite container. Signals from 2 five-inch photomultipliers at each end give energy and event location for single penetrating particles, with relatively good discrimination against natural radioactivity by virtue of the substantial thickness. Data are presented on the response function of the tank, energy resolution, rates and thresholds. A number of modifications that have been tried are also described

  18. HPGe detector shielding adjustment

    International Nuclear Information System (INIS)

    Trnkova, L.; Rulik, P.

    2008-01-01

    Low-level background shielding of HPGe detectors is used mainly for environmental samples with very low content of radionuclides. National Radiation Protection Institute (SURO) in Prague is equipped with 14 HPGe detectors with relative efficiency up to 150%. The detectors are placed in a room built from materials with low content of natural radionuclides and equipped with a double isolation of the floor against radon. Detectors themselves are placed in lead or steel shielding. Steel shielding with one of these detectors with relative efficiency of 100% was chosen to be rebuilt to achieve lower minimum detectable activity (MDA). Additional lead and copper shielding was built up inside the original steel shielding to reduce the volume of the inner space and filled with nitrogen by means of evaporating liquid nitrogen. The additional lead and copper shielding, consequent reduction of the inner volume and supply of evaporated nitrogen, caused a decrease of the background count and accordingly MDA values as well. The effect of nitrogen evaporation on the net areas of peaks belonging to radon daughters is significant. The enhanced shielding adjustment has the biggest influence in low energy range, what can be seen in collected data. MDA values in energy range from 30 keV to 400 keV decreased to 0.65-0.85 of original value, in energy range from 400 keV to 2 MeV they fell to 0.70-0.97 of original value. (authors)

  19. 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 ...

  20. Lepton detector workshop summary

    International Nuclear Information System (INIS)

    Imlay, R.; Iwata, S.; Jacobs, S.

    1976-01-01

    A discussion is given of the initial detector design, focusing on the cost estimates and on the inner detector modules. With regard to inner modules, the rate problem was examined for the closest elements, and the question whether one should use argon or lead-liquid scintillator calorimeters was discussed. New designs which involved major modifications to the lepton detector are considered. The major motivations for alternative designs were twofold. One was that the original detector looked quite expensive, and a study of the tradeoff of money versus physics had not really been done yet. The second point was that, since the physics region to be explored was totally new ground, one would like to leave as many options open as possible and build a detector that was as flexible as possible. A scaled-down version of the original design, which was strongly favored by this study, appears to save an appreciable amount of money with a small decrease in the initial physics scope. The more modular designs seem quite attractive, but not enough time was spent to demonstrate feasibility

  1. Background recognition in Ge detectors by pulse shape analysis

    International Nuclear Information System (INIS)

    Petry, F.; Piepke, A.; Strecker, H.; Klapdor-Kleingrothaus, H.V.; Balysh, A.; Belyaev, S.T.; Demehin, A.; Gurov, A.; Kondratenko, I.; Kotel'nikov, D.; Lebedev, V.I.; Landis, D.; Madden, N.; Pehl, R.H.

    1993-01-01

    A method of event identification that distinguishes single and multiple-site events by determining the number of interactions in a high purity germanium detector is reported. The selectivity of the method has been experimentally verified. (orig.)

  2. Characteristic performance evaluation of a photon counting Si strip detector for low dose spectral breast CT imaging

    Science.gov (United States)

    Cho, Hyo-Min; Barber, William C.; Ding, Huanjun; Iwanczyk, Jan S.; Molloi, Sabee

    2014-01-01

    Purpose: The possible clinical applications which can be performed using a newly developed detector depend on the detector's characteristic performance in a number of metrics including the dynamic range, resolution, uniformity, and stability. The authors have evaluated a prototype energy resolved fast photon counting x-ray detector based on a silicon (Si) strip sensor used in an edge-on geometry with an application specific integrated circuit to record the number of x-rays and their energies at high flux and fast frame rates. The investigated detector was integrated with a dedicated breast spectral computed tomography (CT) system to make use of the detector's high spatial and energy resolution and low noise performance under conditions suitable for clinical breast imaging. The aim of this article is to investigate the intrinsic characteristics of the detector, in terms of maximum output count rate, spatial and energy resolution, and noise performance of the imaging system. Methods: The maximum output count rate was obtained with a 50 W x-ray tube with a maximum continuous output of 50 kVp at 1.0 mA. A109Cd source, with a characteristic x-ray peak at 22 keV from Ag, was used to measure the energy resolution of the detector. The axial plane modulation transfer function (MTF) was measured using a 67 μm diameter tungsten wire. The two-dimensional (2D) noise power spectrum (NPS) was measured using flat field images and noise equivalent quanta (NEQ) were calculated using the MTF and NPS results. The image quality parameters were studied as a function of various radiation doses and reconstruction filters. The one-dimensional (1D) NPS was used to investigate the effect of electronic noise elimination by varying the minimum energy threshold. Results: A maximum output count rate of 100 million counts per second per square millimeter (cps/mm2) has been obtained (1 million cps per 100 × 100 μm pixel). The electrical noise floor was less than 4 keV. The energy resolution

  3. Basis material decomposition method for material discrimination with a new spectrometric X-ray imaging detector

    Science.gov (United States)

    Brambilla, A.; Gorecki, A.; Potop, A.; Paulus, C.; Verger, L.

    2017-08-01

    Energy sensitive photon counting X-ray detectors provide energy dependent information which can be exploited for material identification. The attenuation of an X-ray beam as a function of energy depends on the effective atomic number Zeff and the density. However, the measured attenuation is degraded by the imperfections of the detector response such as charge sharing or pile-up. These imperfections lead to non-linearities that limit the benefits of energy resolved imaging. This work aims to implement a basis material decomposition method which overcomes these problems. Basis material decomposition is based on the fact that the attenuation of any material or complex object can be accurately reproduced by a combination of equivalent thicknesses of basis materials. Our method is based on a calibration phase to learn the response of the detector for different combinations of thicknesses of the basis materials. The decomposition algorithm finds the thicknesses of basis material whose spectrum is closest to the measurement, using a maximum likelihood criterion assuming a Poisson law distribution of photon counts for each energy bin. The method was used with a ME100 linear array spectrometric X-ray imager to decompose different plastic materials on a Polyethylene and Polyvinyl Chloride base. The resulting equivalent thicknesses were used to estimate the effective atomic number Zeff. The results are in good agreement with the theoretical Zeff, regardless of the plastic sample thickness. The linear behaviour of the equivalent lengths makes it possible to process overlapped materials. Moreover, the method was tested with a 3 materials base by adding gadolinium, whose K-edge is not taken into account by the other two materials. The proposed method has the advantage that it can be used with any number of energy channels, taking full advantage of the high energy resolution of the ME100 detector. Although in principle two channels are sufficient, experimental measurements show

  4. A minimum bit error-rate detector for amplify and forward relaying systems

    KAUST Repository

    Ahmed, Qasim Zeeshan; Alouini, Mohamed-Slim; Aissa, Sonia

    2012-01-01

    In this paper, a new detector is being proposed for amplify-and-forward (AF) relaying system when communicating with the assistance of L number of relays. The major goal of this detector is to improve the bit error rate (BER) performance of the system. The complexity of the system is further reduced by implementing this detector adaptively. The proposed detector is free from channel estimation. Our results demonstrate that the proposed detector is capable of achieving a gain of more than 1-dB at a BER of 10 -5 as compared to the conventional minimum mean square error detector when communicating over a correlated Rayleigh fading channel. © 2012 IEEE.

  5. A minimum bit error-rate detector for amplify and forward relaying systems

    KAUST Repository

    Ahmed, Qasim Zeeshan

    2012-05-01

    In this paper, a new detector is being proposed for amplify-and-forward (AF) relaying system when communicating with the assistance of L number of relays. The major goal of this detector is to improve the bit error rate (BER) performance of the system. The complexity of the system is further reduced by implementing this detector adaptively. The proposed detector is free from channel estimation. Our results demonstrate that the proposed detector is capable of achieving a gain of more than 1-dB at a BER of 10 -5 as compared to the conventional minimum mean square error detector when communicating over a correlated Rayleigh fading channel. © 2012 IEEE.

  6. Self-powered in-core neutron detector assembly with uniform perturbation characteristics

    International Nuclear Information System (INIS)

    1981-01-01

    An in-core neutron detector assembly consisting of a number of longitudinally extending self-powered detectors is described. The uniform mechanical structures and materials are placed symmetrically at each active detector portion thus ensuring that local perturbation factors are uniform. (U.K.)

  7. Solid state detector module

    International Nuclear Information System (INIS)

    Hoffman, D. M.

    1985-01-01

    A solid state detector in which each scintillator is optimally configured and coupled with its associated sensing diode in a way which exploits light piping effects to enhance efficiency, and at the same time provide a detector which is modular in nature. To achieve light piping, the scintillator crystal is oriented such that its sides conform with the crystal cleavage plane, and the sides are highly polished. An array of tungsten collimator plates define the individual channels. Multi-channel scintillator/diode modules are mounted behind and in registry with the plurality of collimator plates. A plurality of scintillators are bonded together after coating the surfaces thereof to minimize optical crosstalk. After lapping the face of the scintillator module, it is then bonded to a diode module with individual scintillators in registration with individual diodes. The module is then positioned in the detector array with collimator plates at the junctions between the scintillators

  8. Cryogenic Tracking Detectors

    CERN Multimedia

    Luukka, P R; Tuominen, E M; Mikuz, M

    2002-01-01

    The recent advances in Si and diamond detector technology give hope of a simple solution to the radiation hardness problem for vertex trackers at the LHC. In particular, we have recently demonstrated that operating a heavily irradiated Si detector at liquid nitrogen (LN$_2$) temperature results in significant recovery of Charge Collection Efficiency (CCE). Among other potential benefits of operation at cryogenic temperatures are the use of large low-resistivity wafers, simple processing, higher and faster electrical signal because of higher mobility and drift velocity of carriers, and lower noise of the readout circuit. A substantial reduction in sensor cost could result The first goal of the approved extension of the RD39 program is to demonstrate that irradiation at low temperature in situ during operation does not affect the results obtained so far by cooling detectors which were irradiated at room temperature. In particular we shall concentrate on processes and materials that could significantly reduce th...

  9. The H1 detector

    International Nuclear Information System (INIS)

    Cozzika, G.

    1992-11-01

    The H1 detector presently operating at the HERA e-p collider is described. A general overview of the detector is given with particular emphasis on the calorimeters, the main element of which is a liquid Argon calorimeter enclosed within a large radius solenoid. Calorimetry in the proton direction, close to the beam-pipe is provided by a copper-silicon pad hadronic calorimeter. In the electron direction a lead-scintillator electromagnetic calorimeter closes the solid angle between the rear part of the liquid Argon calorimeter and the beam-pipe. An iron limited streamer tube tail catcher using the return yoke of the solenoid as absorber completes the calorimetry of the detector. The hardware triggers derived from the calorimeters are also described and some performance details of the calorimeters are given

  10. Improved photon detector

    International Nuclear Information System (INIS)

    Zermeno, A.; Marsh, L.M.

    1981-01-01

    Apparatus and methods used to obtain image information from modulation of a uniform flux. A multi-layered detector apparatus is disclosed which comprises a first conductive layer having two sides, a photoconductive layer thick enough to obtain a desired level of sensitivity and resolution of the detector apparatus when the detector apparatus is exposed to radiation of known energy, one side of the photoconductive layer being integrally affixed to and in electrical contact with one side of the first conductive layer, an insulating layer having two sides that is a phosphor that will emit light when irradiated by x-rays, one side of the insulating layer being affixed to the other side of the photoconductive layer and a transparent conductive layer having two sides, one side of the transparent conductive layer being affixed to the other side of the insulating layer. (author)

  11. 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.

  12. Silicon radiation detector

    International Nuclear Information System (INIS)

    Benc, I.; Kerhart, J.; Kopecky, J.; Krca, P.; Veverka, V.; Weidner, M.; Weinova, H.

    1992-01-01

    The silicon radiation detector, which is designed for the detection of electrons with energies above 500 eV and of radiation within the region of 200 to 1100 nm, comprises a PIN or PNN + type photodiode. The active acceptor photodiode is formed by a detector surface of shallow acceptor diffusion surrounded by a collector band of deep acceptor diffusion. The detector surface of shallow P-type diffusion with an acceptor concentration of 10 15 to 10 17 atoms/cm 3 reaches a depth of 40 to 100 nm. One sixth to one eighth of the collector band width is overlapped by the P + collector band at a width of 150 to 300 μm with an acceptor concentration of 10 20 to 10 21 atoms/cm 3 down a depth of 0.5 to 3 μm. This band is covered with a conductive layer, of NiCr for instance. (Z.S.)

  13. Superlattice electroabsorption radiation detector

    International Nuclear Information System (INIS)

    Cooke, B.J.

    1993-06-01

    This paper provides a preliminary investigation of a new class of superlattice electroabsorption radiation detectors that employ direct optical modulation for high-speed, two-dimensional (2-D), high-resolution imaging. Applications for the detector include nuclear radiation measurements, tactical guidance and detection (laser radar), inertial fusion plasma studies, and satellite-based sensors. Initial calculations discussed in this paper indicate that a 1.5-μm (GaAlAs) multi-quantum-well (MQW) Fabry-Perot detector can respond directly to radiation of energies 1 eV to 10 KeV, and indirectly (with scattering targets) up through gamma, with 2-D sample rates on the order of 20 ps

  14. The AFP Detector Control System

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00514541; The ATLAS collaboration

    2017-01-01

    The ATLAS Forward Proton (AFP) detector is one of the forward detectors of the ATLAS experiment at CERN aiming at measuring momenta and angles of diffractively scattered protons. Silicon Tracking and Time-of-Flight detectors are located inside Roman Pot stations inserted into beam pipe aperture. The AFP detector is composed of two stations on each side of the ATLAS interaction point and is under commissioning. The detector is provided with high and low voltage distribution systems. Each station has vacuum and cooling systems, movement control and all the required electronics for signal processing. Monitoring of environmental parameters, like temperature and radiation, is also available. The Detector Control System (DCS) provides control and monitoring of the detector hardware and ensures the safe and reliable operation of the detector, assuring good data quality. Comparing with DCS systems of other detectors, the AFP DCS main challenge is to cope with the large variety of AFP equipment. This paper describes t...

  15. The AFP detector control system

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00514541; The ATLAS collaboration; Caforio, Davide; Czekierda, Sabina; Hajduk, Zbigniew; Olszowska, Jolanta; Sicho, Petr; Zabinski, Bartlomiej

    The ATLAS Forward Proton (AFP) detector is one of the forward detectors of the ATLAS experiment at CERN aiming at measuring momenta and angles of diffractively scattered protons. Silicon Tracking and Time-of-Flight detectors are located inside Roman Pot stations inserted into beam pipe aperture. The AFP detector is composed of two stations on each side of the ATLAS interaction point and is under commissioning. The detector is provided with high and low voltage distribution systems. Each station has vacuum and cooling systems, movement control and all the required electronics for signal processing. Monitoring of environmental parameters, like temperature and radiation, is also available. The Detector Control System (DCS) provides control and monitoring of the detector hardware and ensures the safe and reliable operation of the detector, assuring good data quality. Comparing with DCS systems of other detectors, the AFP DCS main challenge is to cope with the large variety of AFP equipment. This paper describes t...

  16. Fully digital routing logic for single-photon avalanche diode arrays in highly efficient time-resolved imaging

    Science.gov (United States)

    Cominelli, Alessandro; Acconcia, Giulia; Ghioni, Massimo; Rech, Ivan

    2018-03-01

    Time-correlated single-photon counting (TCSPC) is a powerful optical technique, which permits recording fast luminous signals with picosecond precision. Unfortunately, given its repetitive nature, TCSPC is recognized as a relatively slow technique, especially when a large time-resolved image has to be recorded. In recent years, there has been a fast trend toward the development of TCPSC imagers. Unfortunately, present systems still suffer from a trade-off between number of channels and performance. Even worse, the overall measurement speed is still limited well below the saturation of the transfer bandwidth toward the external processor. We present a routing algorithm that enables a smart connection between a 32×32 detector array and five shared high-performance converters able to provide an overall conversion rate up to 10 Gbit/s. The proposed solution exploits a fully digital logic circuit distributed in a tree structure to limit the number and length of interconnections, which is a major issue in densely integrated circuits. The behavior of the logic has been validated by means of a field-programmable gate array, while a fully integrated prototype has been designed in 180-nm technology and analyzed by means of postlayout simulations.

  17. Proceedings of the workshop on radiation detector and its application

    International Nuclear Information System (INIS)

    1996-01-01

    This workshop was held from January 23 to 25, 1996 at National Laboratory for High Energy Physics. At the workshop, lectures were given on the development of the single ion detector using MCP in heavy ion microbeam device, the response of MCP to single heavy ion, the response of a superheated liquid drop type detector to low LET radiation, the response characteristics of a CR-39 flight track detector to hydrogen isotopes, the analysis of small nuclear flight tracks on CR-39 with an interatomic force microscope, charge-sensible amplifiers, the signal-processing circuit for position detection, time and depth-resolved measurement of ion tracks in condensed matter, the response of a thin Si detector to electrons, the method of expressing gas-amplifying rate curves in proportional count gas for low temperature, the characteristics of self annihilating streamer by ultraviolet laser, the development of slow positron beam using radioisotopes, the development of a tunnel junction type x-ray detector, the development of the pattern-analyzing system for PIXE spectra, the characteristics of NE213-CaF 2 bond type neutron detector and many others. In this report, the gists of these papers are collected. (K.I.)

  18. The in-beam tracking detectors for R3B

    Energy Technology Data Exchange (ETDEWEB)

    Paschalis, Stefanos; Johansen, Jacob; Scheit, Heiko [Institut fuer Kernphysik, Technische Universitaet, D 64289 Darmstadt (Germany); Heil, Michael [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, D-64291 Darmstadt (Germany); Aumann, Thomas [Institut fuer Kernphysik, Technische Universitaet, D 64289 Darmstadt (Germany); GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, D-64291 Darmstadt (Germany); Krivshich, Anatoly [PNPI St. Petersburg, 188300 Gatchina (Russian Federation); Collaboration: R3B-Collaboration

    2015-07-01

    The R3B experiment is part of the NUSTAR pillar at FAIR. One of the great strengths of the R3B experiment is the kinematically complete measurement of reactions with exotic ions with energies of up to 1 AGeV. Key components of the R3B experiment are the neutron detector NeuLAND, the γ and charge-particle calorimeter CALIFA, the Si Tracker and the in-beam tracking detectors. A cornerstone instrument of the setup is the new dipole magnet (GLAD) which bends and momentum analyses the high-rigidity beams. A precise tracking of the charged particles through the magnetic field is crucial to resolve the masses of heavy ions and measure the momentum of the fragments with high resolution. In this contribution we present the technical design details of the in-beam tracking detectors that will be used in the R3B experiment together with recent results obtained from in-beam prototype testing. In particular, we discuss Si detectors, detectors based on plastic-scintillator fibers and paddles, straw-tube gas detectors and the overall performance of the system.

  19. Present and future of flat panel detectors in the world

    International Nuclear Information System (INIS)

    Inamura, Kiyonari

    2002-01-01

    Present status of development of flat panel detectors and their clinical application in the world have been surveyed, and future trends are also explored especially in the field of material researches and methods of manufacturing. Also the importance of role of medical physicists on user side is described because characteristic physics measurement of a detector assembly is unavoidable and essential in quality assurance in clinical routine and acceptance test in hospitals. Even though physics measurements and clinical evaluations on flat panel detectors have shown remarkable progress and advances in these several years, future problems of cost down in manufacturing and quality assurance to prevent individual differences between detector assemblies must be resolved. Results of evaluation in mammography, chest radiography, fluoroscopy for cardiovascular examination, bone tumor examination and radiotherapy application indicate that flat panel detectors are future promising materials. Their systematic operation is contributing to heighten accuracy of image examinations and preciseness of radiation therapy. Encouragement to medical physicists relevant to flat panel detectors is also raised in this paper. (author)

  20. Improvement programme of the UA2 detector

    International Nuclear Information System (INIS)

    Merkel, B.

    1985-01-01

    The author describes the process of modifying the present UA2 detector with the aim to match its performance to that of the improved Spp-barS Collider. The new design results from a number of choices dictated by the following considerations: the upgraded UA2 must be operational in 1987, as soon as the Collider resumes operation, in order to maximise its physics output during the period when TEV 1, with nearly three times as high a c.m. energy, has not yet taken over leadership; the upgraded UA2 must remain competitive on the major physics issues rather than diversify its detection capabilities; priority is given to the quality of the missing transverse energy measurement; and modifications to the vertex detector aim at ensuring that multivertex events can be reconstructed and at improving the detector performance in relation with electron identification