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Sample records for high resolution scintillator

  1. High-resolution x-ray imaging using a structured scintillator

    Energy Technology Data Exchange (ETDEWEB)

    Hormozan, Yashar, E-mail: hormozan@kth.se; Sychugov, Ilya; Linnros, Jan [Materials and Nano Physics, School of Information and Communication Technology, KTH Royal Institute of Technology, Electrum 229, Kista, Stockholm SE-16440 (Sweden)

    2016-02-15

    Purpose: In this study, the authors introduce a new generation of finely structured scintillators with a very high spatial resolution (a few micrometers) compared to conventional scintillators, yet maintaining a thick absorbing layer for improved detectivity. Methods: Their concept is based on a 2D array of high aspect ratio pores which are fabricated by ICP etching, with spacings (pitches) of a few micrometers, on silicon and oxidation of the pore walls. The pores were subsequently filled by melting of powdered CsI(Tl), as the scintillating agent. In order to couple the secondary emitted photons of the back of the scintillator array to a CCD device, having a larger pixel size than the pore pitch, an open optical microscope with adjustable magnification was designed and implemented. By imaging a sharp edge, the authors were able to calculate the modulation transfer function (MTF) of this finely structured scintillator. Results: The x-ray images of individually resolved pores suggest that they have been almost uniformly filled, and the MTF measurements show the feasibility of a few microns spatial resolution imaging, as set by the scintillator pore size. Compared to existing techniques utilizing CsI needles as a structured scintillator, their results imply an almost sevenfold improvement in resolution. Finally, high resolution images, taken by their detector, are presented. Conclusions: The presented work successfully shows the functionality of their detector concept for high resolution imaging and further fabrication developments are most likely to result in higher quantum efficiencies.

  2. High-resolution tracking using large capillary bundles filled with liquid scintillator

    CERN Document Server

    Annis, P; Benussi, L; Bruski, N; Buontempo, S; Currat, C; D'Ambrosio, N; Van Dantzig, R; Dupraz, J P; Ereditato, A; Fabre, Jean-Paul; Fanti, V; Feyt, J; Frekers, D; Frenkel, A; Galeazzi, F; Garufi, F; Goldberg, J; Golovkin, S V; Gorin, A M; Grégoire, G; Harrison, K; Höpfner, K; Holtz, K; Konijn, J; Kozarenko, E N; Kreslo, I E; Kushnirenko, A E; Liberti, B; Martellotti, G; Medvedkov, A M; Michel, L; Migliozzi, P; Mommaert, C; Mondardini, M R; Panman, J; Penso, G; Petukhov, Yu P; Rondeshagen, D; Siegmund, W P; Tyukov, V E; Van Beek, G; Vasilchenko, V G; Vilain, P; Visschers, J L; Wilquet, G; Winter, Klaus; Wolff, T; Wörtche, H J; Wong, H; Zimyn, K V

    2000-01-01

    We have developed large high-resolution tracking detectors based on glass capillaries filled with organic liquid scintillator of high refractive index. These liquid-core scintillating optical fibres act simultaneously as detectors of charged particles and as image guides. Track images projected onto the readout end of a capillary bundle are visualized by an optoelectronic chain consisting of a set of image-intensifier tubes followed by a photosensitive CCD or by an EBCCD camera. Two prototype detectors, each composed of \\hbox{$\\approx 10^6$} capillaries with \\hbox{20$-$25 $\\mu$m} diameter and \\hbox{0.9$-$1.8 m} length, have been tested, and a spatial resolution of the order of \\hbox{20$-$40 $\\mu$m} has been attained. A high scintillation efficiency and a large light-attenuation length, in excess of 3 m, was achieved through special purification of the liquid scintillator. Along the tracks of minimum-ionizing particles, the hit densities obtained were $\\sim$ 8 hits/mm at the readout window, and \\hbox{$\\sim$ 3 ...

  3. Gas scintillation glass GEM detector for high-resolution X-ray imaging and CT

    Energy Technology Data Exchange (ETDEWEB)

    Fujiwara, T., E-mail: fujiwara-t@aist.go.jp [Research Institute for Measurement and Analytical Instrumentation, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8568 (Japan); Mitsuya, Y. [Nuclear Professional School, The University of Tokyo, Tokai, Naka, Ibaraki 319-1188 (Japan); Fushie, T. [Radiment Lab. Inc., Setagaya, Tokyo 156-0044 (Japan); Murata, K.; Kawamura, A.; Koishikawa, A. [XIT Co., Naruse, Machida, Tokyo 194-0045 (Japan); Toyokawa, H. [Research Institute for Measurement and Analytical Instrumentation, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8568 (Japan); Takahashi, H. [Institute of Engineering Innovation, School of Engineering, The University of Tokyo, Bunkyo, Tokyo 113-8654 (Japan)

    2017-04-01

    A high-spatial-resolution X-ray-imaging gaseous detector has been developed with a single high-gas-gain glass gas electron multiplier (G-GEM), scintillation gas, and optical camera. High-resolution X-ray imaging of soft elements is performed with a spatial resolution of 281 µm rms and an effective area of 100×100 mm. In addition, high-resolution X-ray 3D computed tomography (CT) is successfully demonstrated with the gaseous detector. It shows high sensitivity to low-energy X-rays, which results in high-contrast radiographs of objects containing elements with low atomic numbers. In addition, the high yield of scintillation light enables fast X-ray imaging, which is an advantage for constructing CT images with low-energy X-rays.

  4. Multi element high resolution scintillator structure

    International Nuclear Information System (INIS)

    Cusano, D.A.

    1980-01-01

    A gamma camera scintillator structure, suitable for detecting high energy gamma photons which, in a single scintillator camera, would require a comparatively thick scintillator crystal, so resulting in unacceptable dispersion of light photons, comprises a collimator array of a high Z material with elongated, parallel wall channels with the scintillator material being disposed in one end of the channels so as to form an integrated collimator/scintillator structure. The collimator channel walls are preferably coated with light reflective material and further light reflective surfaces being translucent to gamma photons, may be provided in each channel. The scintillators may be single crystals or preferably comprise a phosphor dispersed in a thermosetting translucent matrix as disclosed in GB2012800A. The light detectors of the assembled camera may be photomultiplier tubes charge coupled devices or charge injection devices. (author)

  5. Characterization of scintillator-based detectors for few-ten-keV high-spatial-resolution x-ray imaging

    Energy Technology Data Exchange (ETDEWEB)

    Larsson, Jakob C., E-mail: jakob.larsson@biox.kth.se; Lundström, Ulf; Hertz, Hans M. [Biomedical and X-ray Physics, Department of Applied Physics, KTH Royal Institute of Technology/Albanova, Stockholm 10691 (Sweden)

    2016-06-15

    Purpose: High-spatial-resolution x-ray imaging in the few-ten-keV range is becoming increasingly important in several applications, such as small-animal imaging and phase-contrast imaging. The detector properties critically influence the quality of such imaging. Here the authors present a quantitative comparison of scintillator-based detectors for this energy range and at high spatial frequencies. Methods: The authors determine the modulation transfer function, noise power spectrum (NPS), and detective quantum efficiency for Gadox, needle CsI, and structured CsI scintillators of different thicknesses and at different photon energies. An extended analysis of the NPS allows for direct measurements of the scintillator effective absorption efficiency and effective light yield as well as providing an alternative method to assess the underlying factors behind the detector properties. Results: There is a substantial difference in performance between the scintillators depending on the imaging task but in general, the CsI based scintillators perform better than the Gadox scintillators. At low energies (16 keV), a thin needle CsI scintillator has the best performance at all frequencies. At higher energies (28–38 keV), the thicker needle CsI scintillators and the structured CsI scintillator all have very good performance. The needle CsI scintillators have higher absorption efficiencies but the structured CsI scintillator has higher resolution. Conclusions: The choice of scintillator is greatly dependent on the imaging task. The presented comparison and methodology will assist the imaging scientist in optimizing their high-resolution few-ten-keV imaging system for best performance.

  6. Time resolution research in liquid scintillating detection

    International Nuclear Information System (INIS)

    He Hongkun; Shi Haoshan

    2006-01-01

    The signal processing design method is introduced into liquid scintillating detection system design. By analyzing the signal of liquid scintillating detection, improving time resolution is propitious to upgrade efficiency of detecting. The scheme of realization and satisfactory experiment data is demonstrated. Besides other types of liquid scintillating detection is the same, just using more high speed data signal processing techniques and elements. (authors)

  7. Energy resolution of scintillation detectors

    Energy Technology Data Exchange (ETDEWEB)

    Moszyński, M., E-mail: M.Moszynski@ncbj.gov.pl; Syntfeld-Każuch, A.; Swiderski, L.; Grodzicka, M.; Iwanowska, J.; Sibczyński, P.; Szczęśniak, T.

    2016-01-01

    According to current knowledge, the non-proportionality of the light yield of scintillators appears to be a fundamental limitation of energy resolution. A good energy resolution is of great importance for most applications of scintillation detectors. Thus, its limitations are discussed below; which arise from the non-proportional response of scintillators to gamma rays and electrons, being of crucial importance to the intrinsic energy resolution of crystals. The important influence of Landau fluctuations and the scattering of secondary electrons (δ-rays) on intrinsic resolution is pointed out here. The study on undoped NaI and CsI at liquid nitrogen temperature with a light readout by avalanche photodiodes strongly suggests that the non-proportionality of many crystals is not their intrinsic property and may be improved by selective co-doping. Finally, several observations that have been collected in the last 15 years on the influence of the slow components of light pulses on energy resolution suggest that more complex processes are taking place in the scintillators. This was observed with CsI(Tl), CsI(Na), ZnSe(Te), and undoped NaI at liquid nitrogen temperature and, finally, for NaI(Tl) at temperatures reduced below 0 °C. A common conclusion of these observations is that the highest energy resolution, and particularly intrinsic resolution measured with the scintillators, characterized by two or more components of the light pulse decay, is obtainable when the spectrometry equipment integrates the whole light of the components. In contrast, the slow components observed in many other crystals degrade the intrinsic resolution. In the limiting case, afterglow could also be considered as a very slow component that spoils the energy resolution. The aim of this work is to summarize all of the above observations by looking for their origin.

  8. Search for new scintillators for high-energy resolution electromagnetic calorimeters

    International Nuclear Information System (INIS)

    Britvich, G.I.; Britvich, I.G.; Vasil'chenko, V.G.; Lishin, V.A.; Obraztsov, V.F.; Polyakov, V.A.; Solovjev, A.S.

    1999-01-01

    Some opportunities of creation of radiation-resistant heterogeneous electro-magnetic-calorimeters with an energy resolution of about σ/E≅4-5%/√E is given in this article. Investigation results of 2scintillation and radiation characteristics for thin molded plates and new heavy scintillators based on the polystyrene and containing metalloorganic additives are presented. The radiation resistance of thin molded scintillator plates of about 1.1 mm thick containing 2% pTP+0.05% POPOP has reached a level of about 15-20 kGy

  9. Scintillation camera with second order resolution

    International Nuclear Information System (INIS)

    Muehllehner, G.

    1976-01-01

    A scintillation camera for use in radioisotope imaging to determine the concentration of radionuclides in a two-dimensional area is described in which means is provided for second order positional resolution. The phototubes, which normally provide only a single order of resolution, are modified to provide second order positional resolution of radiation within an object positioned for viewing by the scintillation camera. The phototubes are modified in that multiple anodes are provided to receive signals from the photocathode in a manner such that each anode is particularly responsive to photoemissions from a limited portion of the photocathode. Resolution of radioactive events appearing as an output of this scintillation camera is thereby improved

  10. Scintillation camera with second order resolution

    International Nuclear Information System (INIS)

    1975-01-01

    A scintillation camera is described for use in radioisotope imaging to determine the concentration of radionuclides in a two-dimensional area in which means is provided for second-order positional resolution. The phototubes which normally provide only a single order of resolution, are modified to provide second-order positional resolution of radiation within an object positioned for viewing by the scintillation camera. The phototubes are modified in that multiple anodes are provided to receive signals from the photocathode in a manner such that each anode is particularly responsive to photoemissions from a limited portion of the photocathode. Resolution of radioactive events appearing as an output of this scintillation camera is thereby improved

  11. High resolution time-of-flight measurements in small and large scintillation counters

    International Nuclear Information System (INIS)

    D'Agostini, G.; Marini, G.; Martellotti, G.; Massa, F.; Rambaldi, A.; Sciubba, A.

    1981-01-01

    In a test run, the experimental time-of-flight resolution was measured for several different scintillation counters of small (10 x 5 cm 2 ) and large (100 x 15 cm 2 and 75 x 25 cm 2 ) area. The design characteristics were decided on the basis of theoretical Monte Carlo calculations. We report results using twisted, fish-tail, and rectangular light- guides and different types of scintillator (NE 114 and PILOT U). Time resolution up to approx. equal to 130-150 ps fwhm for the small counters and up to approx. equal to 280-300 ps fwhm for the large counters were obtained. The spatial resolution from time measurements in the large counters is also reported. The results of Monte Carlo calculations on the type of scintillator, the shape and dimensions of the light-guides, and the nature of the external wrapping surfaces - to be used in order to optimize the time resolution - are also summarized. (orig.)

  12. A high resolution scintillating fibre (SCIFI) tracking device with CCD readout

    International Nuclear Information System (INIS)

    Atkinson, M.N.; Crennell, D.J.; Fisher, C.M.; Hughes, P.T.; Kirkby, J.; Fent, J.; Freund, P.; Osthoff, A.; Pretzl, K.

    1987-06-01

    The authors present initial test beam measurements of a high resolution scintillating fibre detector with charge coupled device readout. The analysis procedure is discussed and the performance of the detector and its readout assembly is evaluated. A detected photon density is found along minimum ionising tracks of 2.0 mm -1 , with a straight-line RMS residual of 19.3 +- 2.9 μm, giving rise to a track impact parameter precision of 8.8 +- 2.0 μm. The two-track resolution is found to be 52 μm. (author)

  13. High Resolution Tracking Devices Based on Capillaries Filled with Liquid Scintillator

    CERN Multimedia

    Bonekamper, D; Vassiltchenko, V; Wolff, T

    2002-01-01

    %RD46 %title\\\\ \\\\The aim of the project is to develop high resolution tracking devices based on thin glass capillary arrays filled with liquid scintillator. This technique provides high hit densities and a position resolution better than 20 $\\mu$m. Further, their radiation hardness makes them superior to other types of tracking devices with comparable performance. Therefore, the technique is attractive for inner tracking in collider experiments, microvertex devices, or active targets for short-lived particle detection. High integration levels in the read-out based on the use of multi-pixel photon detectors and the possibility of optical multiplexing allow to reduce considerably the number of output channels, and, thus, the cost for the detector.\\\\ \\\\New optoelectronic devices have been developed and tested: the megapixel Electron Bombarded CCD (EBCCD), a high resolution image-detector having an outstanding capability of single photo-electron detection; the Vacuum Image Pipeline (VIP), a high-speed gateable pi...

  14. Ultrahigh resolution radiation imaging system using an optical fiber structure scintillator plate.

    Science.gov (United States)

    Yamamoto, Seiichi; Kamada, Kei; Yoshikawa, Akira

    2018-02-16

    High resolution imaging of radiation is required for such radioisotope distribution measurements as alpha particle detection in nuclear facilities or high energy physics experiments. For this purpose, we developed an ultrahigh resolution radiation imaging system using an optical fiber structure scintillator plate. We used a ~1-μm diameter fiber structured GdAlO 3 :Ce (GAP) /α-Al 2 O 3 scintillator plate to reduce the light spread. The fiber structured scintillator plate was optically coupled to a tapered optical fiber plate to magnify the image and combined with a lens-based high sensitivity CCD camera. We observed the images of alpha particles with a spatial resolution of ~25 μm. For the beta particles, the images had various shapes, and the trajectories of the electrons were clearly observed in the images. For the gamma photons, the images also had various shapes, and the trajectories of the secondary electrons were observed in some of the images. These results show that combining an optical fiber structure scintillator plate with a tapered optical fiber plate and a high sensitivity CCD camera achieved ultrahigh resolution and is a promising method to observe the images of the interactions of radiation in a scintillator.

  15. Measurements of energy resolution with hemispheric scintillators

    International Nuclear Information System (INIS)

    Mendonca, A.C.S.; Binns, D.A.C.; Tauhata, L.; Poledna, R.

    1980-01-01

    The hemispheric configuration is used for plastic scintillators type NE 102 with the aiming to optimize the light collect. Scintillators at this configuration, with radii of 3,81 cm and 2,54 cm, are showing improvement about 16-17% in the energy resolution, on cilyndric scintillators with the same volume, for gamma rays of 511-1275 KeV. (E.G.) [pt

  16. The development of a high-resolution scintillating fiber tracker with silicon photomultiplier readout

    International Nuclear Information System (INIS)

    Roper Yearwood, Gregorio

    2013-01-01

    In this work I present the design and test results for a novel, modular tracking detector from scintillating fibers which are read out by silicon photomultiplier (SiPM) arrays. The detector modules consist of 0.25 mm thin scintillating fibers which are closely packed in five-layer ribbons. Two ribbons are fixed to both sides of a carbon-fiber composite structure. Custom made SiPM arrays with a photo-detection efficiency of about 50% read out the fibers. Several 860 mm long and 32 mm wide tracker modules were tested in a secondary 12 GeV/c beam at the PS facilities, CERN in November of 2009. During this test a spatial resolution better than 0.05 mm at an average light yield of about 20 photons for a minimum ionizing particle was determined. This work details the characterization of scintillating fibers and silicon photomultipliers of different make and model. It gives an overview of the production of scintillating fiber modules. The behavior of detector modules during the test-beam is analyzed in detail and different options for the front-end electronics are compared. Furthermore, the implementation of the proposed tracking detector from scintillating fibers within the scope of the PERDaix experiment is discussed. The PERDaix detector is a permanent magnet spectrometer with a weight of 40 kg. It consists of 8 tracking detector layers from scintillating fibers, a time-of-flight detector from plastic scintillator bars with silicon photomultiplier readout and a transition radiation detector from an irregular fleece radiator and Xe/CO 2 filled proportional counting tubes. The PERDaix detector was launched with a helium balloon within the scope of the ''Balloon-Experiments for University Students'' (BEXUS) program from Kiruna, Sweden in November 2010. For a few hours PERDaix reached an altitude of 33 km and measured cosmic rays. In May 2011, the PERDaix detector was characterized during a test-beam at the PS-facilities at CERN. This work introduces methods for event

  17. High-Resolution PET Detector. Final report

    International Nuclear Information System (INIS)

    Karp, Joel

    2014-01-01

    The objective of this project was to develop an understanding of the limits of performance for a high resolution PET detector using an approach based on continuous scintillation crystals rather than pixelated crystals. The overall goal was to design a high-resolution detector, which requires both high spatial resolution and high sensitivity for 511 keV gammas. Continuous scintillation detectors (Anger cameras) have been used extensively for both single-photon and PET scanners, however, these instruments were based on NaI(Tl) scintillators using relatively large, individual photo-multipliers. In this project we investigated the potential of this type of detector technology to achieve higher spatial resolution through the use of improved scintillator materials and photo-sensors, and modification of the detector surface to optimize the light response function.We achieved an average spatial resolution of 3-mm for a 25-mm thick, LYSO continuous detector using a maximum likelihood position algorithm and shallow slots cut into the entrance surface

  18. Design and test of a high resolution plastic scintillating fiber detector with intensified CCD readout

    International Nuclear Information System (INIS)

    Rebourgeard, P.

    1991-01-01

    We present the design of a particle detector involving a coherent array of 100 000 plastic scintillating microfibers, with an individual core diameter around 50 micrometers, and an intensified bidimensional CCD array. We investigate both theoretically and experimentally the use of polystyrene based scintillators in optical multimodal fibers. The isotropic excitation of modes and the characteristics of energy transfers between the polystyrene matrix and the added fluorescent dyes are of particular interest. An experimental approach is proposed and applied to the development of a new binary scintillator. In order to study the transmission of the signal from the interaction area to the output face, we specify the loss factors, the resolution and the signal to noise ratio within the fiber array. The low light level at the output face of the detector leads us to use image intensifiers in photon counting mode. This requires a detailed analysis of resolutions, gain, noise and detectivity concepts. We propose to describe these strongly correlated notions by the moment generation formalism. Thus, a previous modelisation of the photoelectronic devices allows us to evaluate the performance of the readout chain. A complete detector has been assembled and tested on a high energy hadron beam; the measurements are in good agreement with the modelisation [fr

  19. Factors Influencing Time Resolution of Scintillators and Ways to Improve Them

    CERN Document Server

    Lecoq, P; Brunner, S; Meyer, T; Auffray, E; Knapitsch, A; Jarron, P

    2010-01-01

    The renewal of interest in Time of Flight Positron Emission Tomography (TOF-PET), as well as the necessity to precisely tag events in high energy physics (HEP) experiments at future colliders are pushing for an optimization of all factors affecting the time resolution of the whole acquisition chain comprising the crystal, the photo detector, and the electronics. The time resolution of a scintillator-based detection system is determined by the rate of photo electrons at the detection threshold, which depends on the time distribution of photons being converted in the photo detector. The possibility to achieve time resolution of about 100 ps Full Width at Half Maximum (FWHM) requires an optimization of the light production in the scintillator, the light transport and its transfer from the scintillator to the photo detector. In order to maximize the light yield, and in particular the density of photons in the first nanosecond, while minimizing the rise time and decay time, particular attention must be paid to the...

  20. Development of large-volume, high-resolution tracking detectors based on capillaries filled with liquid scintillator

    International Nuclear Information System (INIS)

    Buontempo, S.; Fabre, J.P.; Frenkel, A.; Gregoire, G.; Hoepfner, K.; Konijn, J.; Kozarenko, E.; Kreslo, I.; Kushnirenko, A.; Martellotti, G.; Michel, L.; Mondardini, M.R.; Penso, G.; Siegmund, W.P.; Strack, R.; Tyukov, V.; Vasilchenko, V.; Vilain, P.; Wilquet, G.; Winter, K.; Wong, H.; Zymin, K.

    1995-01-01

    Searches for the decay of short-lived particles require real time, high-resolution tracking in active targets, which in the case of neutrino physics should be of large volume. The possibility of achieving this by using glass capillaries filled with organic liquid scintillator is being investigated in the framework of the CHORUS experiment at CERN. In this paper, after outlining the application foreseen, advances in the tracking technique are discussed and results from tests are reported. An active target of dimensions 180x2x2 cm 3 has been assembled from capillaries with 20 μm diameter pores. The readout scheme currently in operation allows the reading of similar 5x10 5 channels using a single chain of image intensifiers having a resolution of σ similar 20 μm. Following the development of new liquid scintillators and purification methods an attenuation length of similar 3 m has been obtained. This translates into a hit density of 3.5 per mm for a minimum-ionizing particle that crosses the active target at a distance of 1 m from the readout end. (orig.)

  1. Development of High-Resolution Scintillator Systems

    International Nuclear Information System (INIS)

    Larry A. Franks; Warnick J. Kernan

    2007-01-01

    Mercuric iodide (HgI2) is a well known material for the direct detection of gamma-rays; however, the largest volume achievable is limited by the thickness of the detector which needs to be a small fraction of the average trapping length for electrons. We report results of using HgI2 crystals to fabricate photocells used in the readout of scintillators. The optical spectral response and efficiency of these photocells were measured and will be reported. Nuclear response from an HgI2 photocell that was optically matched to a cerium-activated scintillator is presented and discussed. Further improvements can be expected by optimizing the transparent contact technology

  2. Two-dimensional diced scintillator array for innovative, fine-resolution gamma camera

    International Nuclear Information System (INIS)

    Fujita, T.; Kataoka, J.; Nishiyama, T.; Ohsuka, S.; Nakamura, S.; Yamamoto, S.

    2014-01-01

    We are developing a technique to fabricate fine spatial resolution (FWHM<0.5mm) and cost-effective photon counting detectors, by using silicon photomultipliers (SiPMs) coupled with a finely pixelated scintillator plate. Unlike traditional X-ray imagers that use a micro-columnar CsI(Tl) plate, we can pixelate various scintillation crystal plates more than 1 mm thick, and easily develop large-area, fine-pitch scintillator arrays with high precision. Coupling a fine pitch scintillator array with a SiPM array results in a compact, fast-response detector that is ideal for X-ray, gamma-ray, and charged particle detection as used in autoradiography, gamma cameras, and photon counting CTs. As the first step, we fabricated a 2-D, cerium-doped Gd 3 Al 2 Ga 3 O 12 (Ce:GAGG) scintillator array of 0.25 mm pitch, by using a dicing saw to cut micro-grooves 50μm wide into a 1.0 mm thick Ce:GAGG plate. The scintillator plate is optically coupled with a 3.0×3.0mm pixel 4×4 SiPM array and read-out via the resistive charge-division network. Even when using this simple system as a gamma camera, we obtained excellent spatial resolution of 0.48 mm (FWHM) for 122 keV gamma-rays. We will present our plans to further improve the signal-to-noise ratio in the image, and also discuss a variety of possible applications in the near future

  3. Optimization of the detector and associated electronics used for high-resolution liquid-scintillation alpha spectroscopy

    International Nuclear Information System (INIS)

    Thorngate, J.H.; Christian, D.J.

    1977-01-01

    The performance of various reflector geometries, light coupling liquids, photomultiplier tubes, preamplifiers and linear amplifiers were compared and the configuration found that optimized the combination of pulse-height resolution and pulse-shape discrimination. The best combination used a hemispherical reflector, filled with distilled water, coupled to an 8575 photomultiplier tube, the output of which was conditioned by a special integrating preamplifier and a double-delay-line linear amplifier. Careful choice of the scintillator, sample preparation procedures, and electronic apparatus can produce liquid-scintillation alpha spectroscopy with a pulse-height resolution of 300 keV, or less, and, by using pulse-shape discrimination, background levels as low as 0.01 counts/min. (author)

  4. How Photonic Crystals Can Improve the Timing Resolution of Scintillators

    CERN Document Server

    Lecoq, P; Knapitsch, A

    2013-01-01

    Photonic crystals (PhCs) and quantum optics phenomena open interesting perspectives to enhance the light extraction from scintillating me dia with high refractive indices as demonstrated by our previous work. By doing so, they also in fl uence the timing resolution of scintillators by improving the photostatistics. The present cont ribution will demonstrate that they are actually doing much more. Indeed, photonic crystals, if properly designed, allow the extr action of fast light propagation modes in the crystal with higher efficiency, therefore contributing to increasing the density of photons in the early phase of the light pulse. This is of particular interest to tag events at future high-energy physics colliders, such as CLIC, with a bunch-crossing rate of 2 GHz, as well as for a new generation of time-of-flight positron emission tomographs (TOFPET) aiming at a coincidence timing resolution of 100 ps FWHM. At this level of precision, good control of the light propagation modes is crucial if we consid...

  5. Coincidence resolution time of two small scintillators coupled to high quantum-efficiency photomultipliers in a PET-like system

    Science.gov (United States)

    Galetta, G.; De Leo, R.; Garibaldi, F.; Grodzicka, M.; Lagamba, L.; Loddo, F.; Masiello, G.; Nappi, E.; Perrino, R.; Ranieri, A.; Szczęśniak, T.

    2014-03-01

    The lower limit of the time resolution for a positron emission tomography (PET) system has been measured for two scintillator types, LYSO:Ce and LuAG:Pr. Small dimension crystals and ultra bi-alkali phototubes have been used in order to increase the detected scintillation photons. Good timing resolutions of 118 ps and 223 ps FWHM have been obtained for two LYSO and two LuAG, respectively, exposed to a 22Na source.

  6. Non-Proportionality of Electron Response and Energy Resolution of Compton Electrons in Scintillators

    Science.gov (United States)

    Swiderski, L.; Marcinkowski, R.; Szawlowski, M.; Moszynski, M.; Czarnacki, W.; Syntfeld-Kazuch, A.; Szczesniak, T.; Pausch, G.; Plettner, C.; Roemer, K.

    2012-02-01

    Non-proportionality of light yield and energy resolution of Compton electrons in three scintillators (LaBr3:Ce, LYSO:Ce and CsI:Tl) were studied in a wide energy range from 10 keV up to 1 MeV. The experimental setup was comprised of a High Purity Germanium detector and tested scintillators coupled to a photomultiplier. Probing the non-proportionality and energy resolution curves at different energies was obtained by changing the position of various radioactive sources with respect to both detectors. The distance between both detectors and source was kept small to make use of Wide Angle Compton Coincidence (WACC) technique, which allowed us to scan large range of scattering angles simultaneously and obtain relatively high coincidence rate of 100 cps using weak sources of about 10 μCi activity. The results are compared with those obtained by direct irradiation of the tested scintillators with gamma-ray sources and fitting the full-energy peaks.

  7. A new timing model for calculating the intrinsic timing resolution of a scintillator detector

    International Nuclear Information System (INIS)

    Shao Yiping

    2007-01-01

    The coincidence timing resolution is a critical parameter which to a large extent determines the system performance of positron emission tomography (PET). This is particularly true for time-of-flight (TOF) PET that requires an excellent coincidence timing resolution (<<1 ns) in order to significantly improve the image quality. The intrinsic timing resolution is conventionally calculated with a single-exponential timing model that includes two parameters of a scintillator detector: scintillation decay time and total photoelectron yield from the photon-electron conversion. However, this calculation has led to significant errors when the coincidence timing resolution reaches 1 ns or less. In this paper, a bi-exponential timing model is derived and evaluated. The new timing model includes an additional parameter of a scintillator detector: scintillation rise time. The effect of rise time on the timing resolution has been investigated analytically, and the results reveal that the rise time can significantly change the timing resolution of fast scintillators that have short decay time constants. Compared with measured data, the calculations have shown that the new timing model significantly improves the accuracy in the calculation of timing resolutions

  8. PTR, PCR and Energy Resolution Study of GAGG:Ce Scintillator

    Science.gov (United States)

    Limkitjaroenporn, Pruittipol; Hongtong, Wiraporn; Kim, Hong Joo; Kaewkhao, Jakrapong

    2018-03-01

    In this paper, the peak to total ratio (PTR), the peak to Compton ratio (PCR) and the energy resolution of cerium doped gadolinium aluminium gallium garnet (GAGG:Ce) scintillator are measured in the range of energy from 511 keV to 1332 keV using the radioactive source Na-22, Cs-137 and Co-60. The crystal is coupled with the PMT number R1306 and analyzed by the nuclear instrument module (NIM). The results found that the PTR and PCR of GAGG:Ce scintillator decrease with the increasing of energy. The results of energy resolution show the trend is decrease with the increasing of energy which corresponding to the higher energy resolution at higher energy. Moreover the energy resolution found to be linearly with.

  9. High-Z Nanoparticle/Polymer Nanocomposites for Gamma-Ray Scintillation Detectors

    Science.gov (United States)

    Liu, Chao

    An affordable and reliable solution for spectroscopic gamma-ray detection has long been sought after due to the needs from research, defense, and medical applications. Scintillators resolve gamma energy by proportionally converting a single high-energy photon into a number of photomultiplier-tube-detectable low-energy photons, which is considered a more affordable solution for general purposes compared to the delicate semiconductor detectors. An ideal scintillator should simultaneously exhibit the following characteristics: 1) high atomic number (Z) for high gamma stopping power and photoelectron production; 2) high light yield since the energy resolution is inversely proportional to the square root of light yield; 3) short emission decay lifetime; and 4) low cost and scalable production. However, commercial scintillators made from either inorganic single crystals or plastics fail to satisfy all requirements due to their intrinsic material properties and fabrication limitations. The concept of adding high-Z constituents into plastic scintillators to harness high Z, low cost, and fast emission in the resulting nanocomposite scintillators is not new in and of itself. Attempts have been made by adding organometallics, quantum dots, and scintillation nanocrystals into the plastic matrix. High-Z organometallics have long been used to improve the Z of plastic scintillators; however, their strong spin-orbit coupling effect entails careful triplet energy matching using expensive triplet emitters to avoid severe quenching of the light yield. On the other hand, reported quantum dot- and nanocrystal-polymer nanocomposites suffer from moderate Z and high optical loss due to aggregation and self-absorption at loadings higher than 10 wt%, limiting their potential for practical application. This dissertation strives to improve the performance of nanoparticle-based nanocomposite scintillators. One focus is to synthesize transparent nanocomposites with higher loadings of high

  10. Semiconductor high-energy radiation scintillation detector

    International Nuclear Information System (INIS)

    Kastalsky, A.; Luryi, S.; Spivak, B.

    2006-01-01

    We propose a new scintillation-type detector in which high-energy radiation generates electron-hole pairs in a direct-gap semiconductor material that subsequently recombine producing infrared light to be registered by a photo-detector. The key issue is how to make the semiconductor essentially transparent to its own infrared light, so that photons generated deep inside the semiconductor could reach its surface without tangible attenuation. We discuss two ways to accomplish this, one based on doping the semiconductor with shallow impurities of one polarity type, preferably donors, the other by heterostructure bandgap engineering. The proposed semiconductor scintillator combines the best properties of currently existing radiation detectors and can be used for both simple radiation monitoring, like a Geiger counter, and for high-resolution spectrography of the high-energy radiation. An important advantage of the proposed detector is its fast response time, about 1 ns, essentially limited only by the recombination time of minority carriers. Notably, the fast response comes without any degradation in brightness. When the scintillator is implemented in a qualified semiconductor material (such as InP or GaAs), the photo-detector and associated circuits can be epitaxially integrated on the scintillator slab and the structure can be stacked-up to achieve virtually any desired absorption capability

  11. Measurement of the time resolution of small SiPM-based scintillation counters

    Science.gov (United States)

    Kravchenko, E. A.; Porosev, V. V.; Savinov, G. A.

    2017-12-01

    In this research, we evaluated the timing resolution of SiPM-based scintillation detector on a 1-GeV electron beam "extracted" from VEPP-4M. We tested small scintillation crystals of pure CsI, YAP, LYSO, and LFS-3 with HAMAMATSU S10362-33-025C and S13360-3050CS. The CsI scintillator together with HAMAMATSU S13360-3050CS demonstrated the best results. Nevertheless, the achieved time resolution of ~80 ps (RMS) relates mainly to the photodetector itself. It makes the silicon photomultiplier an attractive candidate to replace other devices in applications where sub-nanosecond accuracy is required.

  12. Clinical dosimetry with plastic scintillators - Almost energy independent, direct absorbed dose reading with high resolution

    Energy Technology Data Exchange (ETDEWEB)

    Quast, U; Fluehs, D [Department of Radiotherapy, Essen (Germany). Div. of Clinical Radiation Physics; Fluehs, D; Kolanoski, H [Dortmund Univ. (Germany). Inst. fuer Physik

    1996-08-01

    Clinical dosimetry is still far behind the goal to measure any spatial or temporal distribution of absorbed dose fast and precise without disturbing the physical situation by the dosimetry procedure. NE 102A plastic scintillators overcome this border. These tissue substituting dosemeter probes open a wide range of new clinical applications of dosimetry. This versatile new dosimetry system enables fast measurement of the absorbed dose to water in water also in regions with a steep dose gradient, close to interfaces, or in partly shielded regions. It allows direct reading dosimetry in the energy range of all clinically used external photon and electron beams, or around all branchytherapy sources. Thin detector arrays permit fast and high resolution measurements in quality assurance, such as in-vivo dosimetry or even afterloading dose monitoring. A main field of application is the dosimetric treatment planning, the individual optimization of brachytherapy applicators. Thus, plastic scintillator dosemeters cover optimally all difficult fields of clinical dosimetry. An overview about its characteristics and applications is given here. 20 refs, 1 fig.

  13. Liquid Scintillation High Resolution Spectral Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Grau Carles, A.; Grau Malonda, A.

    2010-08-06

    The CIEMAT/NIST and the TDCR methods in liquid scintillation counting are based on the determination of the efficiency for total counting. This paper tries to expand these methods analysing the pulse-height spectrum of radionuclides. To reach this objective we have to generalize the equations used in the model and to analyse the influence of ionization and chemical quench in both spectra and counting efficiency. We present equations to study the influence of different photomultipliers response in systems with one, two or three photomultipliers. We study the effect of the electronic noise discriminator level in both spectra and counting efficiency. The described method permits one to study problems that up to now was not possible to approach, such as the high uncertainty in the standardization of pure beta-ray emitter with low energy when we apply the TDCR method, or the discrepancies in the standardization of some electron capture radionuclides, when the CIEMAT/NIST method is applied. (Author) 107 refs.

  14. Liquid Scintillation High Resolution Spectral Analysis

    International Nuclear Information System (INIS)

    Grau Carles, A.; Grau Malonda, A.

    2010-01-01

    The CIEMAT/NIST and the TDCR methods in liquid scintillation counting are based on the determination of the efficiency for total counting. This paper tries to expand these methods analysing the pulse-height spectrum of radionuclides. To reach this objective we have to generalize the equations used in the model and to analyse the influence of ionization and chemical quench in both spectra and counting efficiency. We present equations to study the influence of different photomultipliers response in systems with one, two or three photomultipliers. We study the effect of the electronic noise discriminator level in both spectra and counting efficiency. The described method permits one to study problems that up to now was not possible to approach, such as the high uncertainty in the standardization of pure beta-ray emitter with low energy when we apply the TDCR method, or the discrepancies in the standardization of some electron capture radionuclides, when the CIEMAT/NIST method is applied. (Author) 107 refs.

  15. Recipe for attaining optimal energy resolution in inorganic scintillators

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Jai; Koblov, Alexander [School of Engineering and IT, B-purple-12, Faculty of EHSE, Charles Darwin University, Darwin, NT 0909 (Australia)

    2012-12-15

    Using an approximate form of the density of excitation created within the track initiated by an incident {gamma} - photon on a scintillator, the light yield is derived as a function of linear, bimolecular and Auger radiative and quenching recombination rates. The non-proportionality in the yield is analysed as a function of the bimolecular and Auger quenching rates and also its dependence on the track radius is studied. An optimal combination of these quenching rates and track radius is presented to obtain a recipe for inventing a scintillator material with optimal energy resolution. The importance of the mobility of charge carriers in minimising the non-proportionality in a scintillator is also discussed (copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  16. Recipe for attaining optimal energy resolution in inorganic scintillators

    International Nuclear Information System (INIS)

    Singh, Jai; Koblov, Alexander

    2012-01-01

    Using an approximate form of the density of excitation created within the track initiated by an incident γ - photon on a scintillator, the light yield is derived as a function of linear, bimolecular and Auger radiative and quenching recombination rates. The non-proportionality in the yield is analysed as a function of the bimolecular and Auger quenching rates and also its dependence on the track radius is studied. An optimal combination of these quenching rates and track radius is presented to obtain a recipe for inventing a scintillator material with optimal energy resolution. The importance of the mobility of charge carriers in minimising the non-proportionality in a scintillator is also discussed (copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  17. New detector developments for high resolution positron emission tomography

    International Nuclear Information System (INIS)

    Ziegler, S.I.; Pichler, B.; Lorenz, E.

    1998-01-01

    The strength of quantitative, functional imaging using positron emission tomography, specially in small animals, is limited due to the spatial resolution. Therefore, various tomograph designs employing new scintillators, light sensors, or coincidence electronic are investigated to improve resolution without losses in sensitivity. Luminous scintillators with short light decay time in combination with novel readout schemes using photomultipliers or semiconductor detectors are currently tested by several groups and are implemented in tomographs for small animals. This review summarises the state of development in high resolution positron emission tomography with a detailed description of a system incorporating avalanche photodiode arrays and small scintillation crystals. (orig.) [de

  18. High pressure gas scintillation drift chambers with wave-shifter fiber readout

    International Nuclear Information System (INIS)

    Parsons, A.; Edberg, T.K.; Sadoulet, B.; Weiss, S.; Wilkerson, J.; Hurley, K.; Lin, R.P.

    1990-01-01

    The authors present results from a prototype high pressure xenon gas scintillation drift chamber using a novel wave-shifter fiber readout scheme. They have measured the primary scintillation light yield to be one photon per 76 ± 12 eV deposited energy. They present initial results of our chamber for the two-interaction separation (< 4 mm in the drift direction, ∼ 7 mm orthogonal to the drift); for the position resolution (< 400 μm rms in the plane orthogonal to the drift direction); and for the energy resolution (ΔE/E < 6% FWHM at 122 keV)

  19. Can Transient Phenomena Help Improving Time Resolution in Scintillators?

    CERN Document Server

    Lecoq, P; Vasiliev, A

    2014-01-01

    The time resolution of a scintillator-based detector is directly driven by the density of photoelectrons generated in the photodetector at the detection threshold. At the scintillator level it is related to the intrinsic light yield, the pulse shape (rise time and decay time) and the light transport from the gamma-ray conversion point to the photodetector. When aiming at 10 ps time resolution, fluctuations in the thermalization and relaxation time of hot electrons and holes generated by the interaction of ionization radiation with the crystal become important. These processes last for up to a few tens of ps and are followed by a complex trapping-detrapping process, Poole-Frenkel effect, Auger ionization of traps and electron-hole recombination, which can last for a few ns with very large fluctuations. This paper will review the different processes at work and evaluate if some of the transient phenomena taking place during the fast thermalization phase can be exploited to extract a time tag with a precision in...

  20. WE-H-207A-01: Computational Evaluation of High-Resolution 18F Positron Imaging Using Radioluminescence Microscopy with Lu2O3: Eu Thin-Film Scintillator

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Q; Sengupta, D; Pratx, G [Stanford University, Palo Alto, CA (United States)

    2016-06-15

    Purpose: Radioluminescence microscopy, an emerging and powerful tool for high resolution beta imaging, has been applied to molecular imaging of cellular metabolism to understand tumor biology. A novel thin-film (10 µm thickness) scintillator made of Lu{sub 2}O{sub 3}: Eu has been developed to enhance the system performance. However the advances of radioluminescence imaging with Lu{sub 2}O{sub 3}scintillator compared with that using conventional scintillator have not been explored theoretically to date. To validate the advantages of the thin-film scintillator, this study uses a novel computational simulation framework to evaluate the performance of radioluminescence microscopy using both conventional and thin-film scintillators. Methods: Numerical models for different stages of positron imaging are established. Positron from {sup 18}F passing through the scintillator and its neighbor structures are modeled by Monte-Carlo simulation using Geant4. The propagation and focus of photons by the microscope are modeled by convolution with a depth-varying point spread function generated by the Gibson-Lanni model. Photons focused on the detector plane are then captured and converted into electronic signals by an electron multiplication (EM) CCD camera, which is described by a photosensor model considering various noises and charge amplification. Results: The performance metrics of radioluminescence imaging with a thin-film Lu{sub 2}O{sub 3} and conventional CdWO{sub 4} scintillator are compared, including spatial resolution, sensitivity, positron track area and intensity. The spatial resolution of Lu{sub 2}O{sub 3} system can achieve 10 µm maximally, a 12 µm enhancement from that obtained from CdWO{sub 4} system. Meanwhile, the system with Lu{sub 2}O{sub 3} scintillator can provide a higher mean sensitivity: 40% compared with that (21.5%) obtained from CdWO{sub 4} system. Moreover, the simulation results are in good agreement with previous experimental measurements

  1. Recent advances in the use of ASEDRA in post processing scintillator spectra for resolution enhancement

    International Nuclear Information System (INIS)

    Sjoden, G.E.

    2012-01-01

    The ASEDRA (Advanced Synthetically Enhanced Detector Resolution Algorithm, patent pending) has been successfully applied as a post processing algorithm to both sodium iodide (NaI(Tl)) and cesium iodide (CsI(Na)) scintillator detectors to synthetically enhance their realized spectral data resolution by as much as a factor of three, wherein from these detectors the 'raw' unprocessed spectra are traditionally of poor resolution. ASEDRA uses noise reduction and built-in high resolution Monte Carlo radiation transport based detector response functions (DRFs) to rapidly post-process a spectrum in a few seconds on a standard laptop; gamma lines are extracted with an accuracy that makes the scintillator detectors competitive with higher resolution, higher material cost detectors. ASEDRA differs from other tools in the field, such as Sandia's GADRAS software, in that ASEDRA performs a differential spectrum attribution and cumulative extraction from the sample spectrum, rather than an integral-based approach, as in GADRAS. Previous publications have highlighted the successful application of ASEDRA in samples with plutonium and various isotopes. A new SmartID nuclide identification package to accompany ASEDRA has recently been implemented for test and evaluation purposes for sample attribution; in addition, the application of ASEDRA+SmartID has occurred with success in long dwell cargo monitoring and SNM detection applications, enabling new protocols for HEU detection. Overall, this paper presents recent developments and results along with a discussion of follow-on steps in the development of ASEDRA as an effective field gamma spectrum analysis tool for low cost scintillators. (author)

  2. High-pressure 3He gas scintillation neutron spectrometer

    International Nuclear Information System (INIS)

    Derzon, M.S.; Slaughter, D.R.; Prussin, S.G.

    1985-10-01

    A high-pressure, 3 He-Xe gas scintillation spectrometer has been developed for neutron spectroscopy on D-D fusion plasmas. The spectrometer exhibits an energy resolution of (121 +- 20 keV) keV (FWHM) at 2.5 MeV and an efficiency of (1.9 +- 0.4) x 10 -3 (n/cm 2 ) -1 . The contribution to the resolution (FWHM) from counting statistics is only (22 +- 3 keV) and the remainder is due predominantly to the variation of light collection efficiency with location of neutron events within the active volume of the detector

  3. New generation of efficient high resolution detector for 30-100 keV photons

    DEFF Research Database (Denmark)

    Olsen, Ulrik Lund

    between pores. The potential of the structured scintillator is explored through Monte Carlo simulations. A spatial resolution of 1 µm is obtainable and for scintillators with a resolution between 1 µm and 8 µm the efficiency could be more than 15 times higher than a regular scintillator with corresponding...... detector. This establishes an inverse correlation between the spatial resolution and the detection efficiency which limits the performance of existing x-ray detectors. The purpose of this Ph.D. project is to explore alternative paths of research, to develop x-ray detectors for the 30-100 keV energy range...... with single micrometre resolution without compromising efficiency. A number of detector types have been evaluated for this purpose. Structured scintillators are found to exhibit a high potential in terms of performance and also in terms of realizing an actual detector. The structured scintillator consists...

  4. High effective atomic number polymer scintillators for gamma ray spectroscopy

    Science.gov (United States)

    Cherepy, Nerine Jane; Sanner, Robert Dean; Payne, Stephen Anthony; Rupert, Benjamin Lee; Sturm, Benjamin Walter

    2014-04-15

    A scintillator material according to one embodiment includes a bismuth-loaded aromatic polymer having an energy resolution at 662 keV of less than about 10%. A scintillator material according to another embodiment includes a bismuth-loaded aromatic polymer having a fluor incorporated therewith and an energy resolution at 662 keV of less than about 10%. Additional systems and methods are also presented.

  5. Development of a compact scintillator-based high-resolution Compton camera for molecular imaging

    Energy Technology Data Exchange (ETDEWEB)

    Kishimoto, A., E-mail: daphne3h-aya@ruri.waseda.jp [Research Institute for Science and Engineering, Waseda University, 3-4-1 Ohkubo, Shinjuku, Tokyo (Japan); Kataoka, J.; Koide, A.; Sueoka, K.; Iwamoto, Y.; Taya, T. [Research Institute for Science and Engineering, Waseda University, 3-4-1 Ohkubo, Shinjuku, Tokyo (Japan); Ohsuka, S. [Central Research Laboratory, Hamamatsu Photonics K.K., 5000 Hirakuchi, Hamakita-ku, Hamamatsu, Shizuoka (Japan)

    2017-02-11

    The Compton camera, which shows gamma-ray distribution utilizing the kinematics of Compton scattering, is a promising detector capable of imaging across a wide range of energy. In this study, we aim to construct a small-animal molecular imaging system in a wide energy range by using the Compton camera. We developed a compact medical Compton camera based on a Ce-doped Gd{sub 3}Al{sub 2}Ga{sub 3}O{sub 12} (Ce:GAGG) scintillator and multi-pixel photon counter (MPPC). A basic performance confirmed that for 662 keV, the typical energy resolution was 7.4 % (FWHM) and the angular resolution was 4.5° (FWHM). We then used the medical Compton camera to conduct imaging experiments based on a 3-D imaging reconstruction algorithm using the multi-angle data acquisition method. The result confirmed that for a {sup 137}Cs point source at a distance of 4 cm, the image had a spatial resolution of 3.1 mm (FWHM). Furthermore, we succeeded in producing 3-D multi-color image of different simultaneous energy sources ({sup 22}Na [511 keV], {sup 137}Cs [662 keV], and {sup 54}Mn [834 keV]).

  6. A high-resolution tracking hodoscope based on capillary layers filled with liquid scintillator

    CERN Document Server

    Bay, A; Bruski, N; Buontempo, S; Currat, C; D'Ambrosio, N; Ekimov, A V; Ereditato, A; Fabre, Jean-Paul; Fanti, V; Frekers, D; Frenkel, A; Golovkin, S V; Govorun, V N; Harrison, K; Koppenburg, P; Kozarenko, E N; Kreslo, I E; Liberti, B; Martellotti, G; Medvedkov, A M; Mondardini, M R; Penso, G; Siegmund, W P; Vasilchenko, V G; Vilain, P; Wilquet, G; Winter, Klaus; Wörtche, H J

    2001-01-01

    Results are given on tests of a high-resolution tracking hodoscope based on layers of \\hbox{26-$\\mu$m-bore} glass capillaries filled with organic liquid scintillator (1-methylnaphthalene doped with R39). The detector prototype consisted of three 2-mm-thick parallel layers, with surface areas of $2.1 \\times 21$~cm$^2$. The layers had a centre-to-centre spacing of 6~mm, and were read by an optoelectronic chain comprising two electrostatically focused image intensifiers and an Electron-Bombarded Charge-Coupled Device (EBCCD). Tracks of cosmic-ray particles were recorded and analysed. The observed hit density was 6.6~hits/mm for particles crossing the layers perpendicularly, at a distance of 1~cm from the capillaries' readout end, and 4.2~hits/mm for particles at a distance of 20~cm. A track segment reconstructed in a single layer had an rms residual of $\\sim$~20~$\\mu$m, and allowed determination of the track position in a neighbouring layer with a precision of $\\sim$~170~$\\mu$m. This latter value corresponded to...

  7. An instrument for the high-statistics measurement of plastic scintillating fibers

    International Nuclear Information System (INIS)

    Buontempo, S.; Ereditato, A.; Marchetti-Stasi, F.; Riccardi, F.; Strolin, P.

    1994-01-01

    There is today widespread use of plastic scintillating fibers in particle physics, mainly for calorimetric and tracking applications. In the case of calorimeters, we have to cope with very massive detectors and a large quantity of scintillating fibers. The CHORUS Collaboration has built a new detector to search for ν μ -ν τ oscillations in the CERN neutrino beam. A crucial task of the detector is ruled by the high-energy resolution calorimeter. For its construction more than 400 000 scintillating plastic fibers have been used. In this paper we report on the design and performance of a new instrument for the high-statistics measurement of the fiber properties, in terms of light yield and light attenuation length. The instrument has been successfully used to test about 3% of the total number of fibers before the construction of the calorimeter. ((orig.))

  8. Calculations and measurements of the scintillator-to-water stopping power ratio of liquid scintillators for use in proton radiotherapy

    International Nuclear Information System (INIS)

    Scott Ingram, W.; Robertson, Daniel; Beddar, Sam

    2015-01-01

    Liquid scintillators are a promising detector for high-resolution three-dimensional proton therapy dosimetry. Because the scintillator comprises both the active volume of the detector and the phantom material, an ideal scintillator will exhibit water equivalence in its radiological properties. One of the most fundamental of these is the scintillator’s stopping power. The objective of this study was to compare calculations and measurements of scintillator-to-water stopping power ratios to evaluate the suitability of the liquid scintillators BC-531 and OptiPhase HiSafe 3 for proton dosimetry. We also measured the relative scintillation output of the two scintillators. Both calculations and measurements show that the linear stopping power of OptiPhase is significantly closer to water than that of BC-531. BC-531 has a somewhat higher scintillation output. OptiPhase can be mixed with water at high concentrations, which further improves its scintillator-to-water stopping power ratio. However, this causes the solution to become cloudy, which has a negative impact on the scintillation output and spatial resolution of the detector. OptiPhase is preferred over BC-531 for proton dosimetry because its density and scintillator-to-water stopping power ratio are more water equivalent

  9. High-spatial resolution and high-spectral resolution detector for use in the measurement of solar flare hard x rays

    International Nuclear Information System (INIS)

    Desai, U.D.; Orwig, L.E.

    1988-01-01

    In the areas of high spatial resolution, the evaluation of a hard X-ray detector with 65 micron spatial resolution for operation in the energy range from 30 to 400 keV is proposed. The basic detector is a thick large-area scintillator faceplate, composed of a matrix of high-density scintillating glass fibers, attached to a proximity type image intensifier tube with a resistive-anode digital readout system. Such a detector, combined with a coded-aperture mask, would be ideal for use as a modest-sized hard X-ray imaging instrument up to X-ray energies as high as several hundred keV. As an integral part of this study it was also proposed that several techniques be critically evaluated for X-ray image coding which could be used with this detector. In the area of high spectral resolution, it is proposed to evaluate two different types of detectors for use as X-ray spectrometers for solar flares: planar silicon detectors and high-purity germanium detectors (HPGe). Instruments utilizing these high-spatial-resolution detectors for hard X-ray imaging measurements from 30 to 400 keV and high-spectral-resolution detectors for measurements over a similar energy range would be ideally suited for making crucial solar flare observations during the upcoming maximum in the solar cycle

  10. Scintillation hodoscopes on the basis of hodoscopic photomultipliers using scintillation fibers

    International Nuclear Information System (INIS)

    Alimova, T.V.; Vasil'chenko, V.G.; Vechkanov, G.N.

    1986-01-01

    Scintillation hodoscopes characteristics and their design features have been considered. The space resolution for hodoscopes consisting of 4 layers of scintillation fibres 200 mm long and 1 mm in diameter is 0.4-0.6 mm. With 2 fibres layer 1 m long and 3.8 mm in diameter the space resolution 3 mm has been obtained. A possibility to construct 0.1 mm resolution scintillation hodoscopes is discussed

  11. Development and Studies of Novel Microfabricated Radiation Hard Scintillation Detectors With High Spatial Resolution

    CERN Document Server

    Mapelli, A; Haguenauer, M; Jiguet, S; Renaud, P; Vico Triviño, N

    2011-01-01

    A new type of scintillation detector is being developed with standard microfabrication techniques. It consists of a dense array of scintillating waveguides obtained by coupling microfluidic channels filled with a liquid scintillator to photodetectors. Easy manipulation of liquid scintillators inside microfluidic devices allow their flushing, renewal, and exchange making the active medium intrinsically radiation hard. Prototype detectors have been fabricated by photostructuration of a radiation hard epoxy resin (SU-8) deposited on silicon wafers and coupled to a multi-anode photomultiplier tube (MAPMT) to read-out the scintillation light. They have been characterized by exciting the liquid scintillator in the 200 micrometers thick microchannels with electrons from a 90Sr yielding approximately 1 photoelectron per impinging Minimum Ionizing Particle (MIP). These promising results demonstrate the concept of microfluidic scintillating detection and are very encouraging for future developments.

  12. Study of resolution and linearity in LaBr3: Ce scintillator through digital-pulse processing

    International Nuclear Information System (INIS)

    Abhinav Kumar; Mishra, Gaurav; Ramachandran, K.

    2014-01-01

    Advent of digital pulse processing has led to a paradigm shift in pulse processing techniques by replacing analog electronics processing chain with equivalent algorithms acting on pulse profiles digitized at high sampling rates. In this paper, we have carried out offline digital pulse processing of Cerium-doped Lanthanum bromide scintillator (LaBr 3 : Ce) detector pulses, acquired using CAEN V1742 VME digitizer module. Algorithms have been written to approximate the functioning of peak sensing analog-to-digital convertor (ADC) and charge-to-digital convertor (QDC). Energy dependence of resolution and energy linearity of LaBr 3 : Ce scintillator detector has been studied by utilizing aforesaid algorithms

  13. Energy resolution limitations in a gas scintillation proportional counter

    International Nuclear Information System (INIS)

    Simons, D.G.; de Korte, P.A.J.; Peacock, A.; Bleeker, J.A.M.

    1985-01-01

    An investigation is made of the factors limiting the energy resolution of a gas scintillation proportional counter (GSPC). Several of these limitations originate in the drift region of such a counter and data is presented, giving a quantitative description of those effects. Data is also presented of a GSPC without a drift region, that therefore largely circumvents most of those degrading factors. The results obtained so far indicate that in that detector the limitation to the resolution is most probably due to cleanliness of the gas. Further research is underway in order to assess quantitatively the limiting factors in such a driftless GSPC

  14. Plastic scintillator

    International Nuclear Information System (INIS)

    Andreeshchev, E.A.; Kilin, S.F.; Kavyrzina, K.A.

    1978-01-01

    A plastic scintillator for ionizing radiation detectors with high time resolution is suggested. To decrease the scintillation pulse width and to maintain a high light yield, the 4 1 , 4 5 -dibromo-2 1 , 2 5 , 5 1 , 5 5 -tetramethyl-n-quinquiphenyl (Br 2 Me 4 Ph) in combination with n-terphenyl (Ph 3 ) or 2, 5-diphenyloxadiazol-1, 3, 4 (PPD) is used as a luminescent addition. Taking into consideration the results of a special study, it is shown, that the following ratio of ingradients is the optimum one: 3-4 mass% Ph 3 or 4-7 mas% PPD + 2-5 mass% Br 2 Me 4 Ph + + polymeric base. The suggested scintillator on the basis of polystyrene has the light yield of 0.23-0.26 arbitrary units and the scintillation pulse duration at half-height is 0.74-0.84 ns

  15. High spatial resolution radiation detectors based on hydrogenated amorphous silicon and scintillator

    International Nuclear Information System (INIS)

    Jing, T.; Lawrence Berkeley Lab., CA

    1995-05-01

    Hydrogenated amorphous silicon (a-Si:H) as a large-area thin film semiconductor with ease of doping and low-cost fabrication capability has given a new impetus to the field of imaging sensors; its high radiation resistance also makes it a good material for radiation detectors. In addition, large-area microelectronics based on a-Si:H or polysilicon can be made with full integration of peripheral circuits, including readout switches and shift registers on the same substrate. Thin a-Si:H p-i-n photodiodes coupled to suitable scintillators are shown to be suitable for detecting charged particles, electrons, and X-rays. The response speed of CsI/a-Si:H diode combinations to individual particulate radiation is limited by the scintillation light decay since the charge collection time of the diode is very short (< 10ns). The reverse current of the detector is analyzed in term of contact injection, thermal generation, field enhanced emission (Poole-Frenkel effect), and edge leakage. A good collection efficiency for a diode is obtained by optimizing the p layer of the diode thickness and composition. The CsI(Tl) scintillator coupled to an a-Si:H photodiode detector shows a capability for detecting minimum ionizing particles with S/N ∼20. In such an arrangement a p-i-n diode is operated in a photovoltaic mode (reverse bias). In addition, a p-i-n diode can also work as a photoconductor under forward bias and produces a gain yield of 3--8 for shaping times of 1 micros. The mechanism of the formation of structured CsI scintillator layers is analyzed. Initial nucleation in the deposited layer is sensitive to the type of substrate medium, with imperfections generally catalyzing nucleation. Therefore, the microgeometry of a patterned substrate has a significant effect on the structure of the CsI growth

  16. High spatial resolution radiation detectors based on hydrogenated amorphous silicon and scintillator

    Energy Technology Data Exchange (ETDEWEB)

    Jing, Tao [Univ. of California, Berkeley, CA (United States). Dept. of Engineering-Nuclear Engineering

    1995-05-01

    Hydrogenated amorphous silicon (a-Si:H) as a large-area thin film semiconductor with ease of doping and low-cost fabrication capability has given a new impetus to the field of imaging sensors; its high radiation resistance also makes it a good material for radiation detectors. In addition, large-area microelectronics based on a-Si:H or polysilicon can be made with full integration of peripheral circuits, including readout switches and shift registers on the same substrate. Thin a-Si:H p-i-n photodiodes coupled to suitable scintillators are shown to be suitable for detecting charged particles, electrons, and X-rays. The response speed of CsI/a-Si:H diode combinations to individual particulate radiation is limited by the scintillation light decay since the charge collection time of the diode is very short (< 10ns). The reverse current of the detector is analyzed in term of contact injection, thermal generation, field enhanced emission (Poole-Frenkel effect), and edge leakage. A good collection efficiency for a diode is obtained by optimizing the p layer of the diode thickness and composition. The CsI(Tl) scintillator coupled to an a-Si:H photodiode detector shows a capability for detecting minimum ionizing particles with S/N ~20. In such an arrangement a p-i-n diode is operated in a photovoltaic mode (reverse bias). In addition, a p-i-n diode can also work as a photoconductor under forward bias and produces a gain yield of 3--8 for shaping times of 1 {micro}s. The mechanism of the formation of structured CsI scintillator layers is analyzed. Initial nucleation in the deposited layer is sensitive to the type of substrate medium, with imperfections generally catalyzing nucleation. Therefore, the microgeometry of a patterned substrate has a significant effect on the structure of the CsI growth.

  17. Properties of high pressure nitrogen-argon and nitrogen-xenon gas scintillators

    International Nuclear Information System (INIS)

    Tornow, W.; Huck, H.; Koeber, H.J.; Mertens, G.

    1976-01-01

    Investigations of scintillation light output and energy resolution have been made at pressures up to 90 atm in gaseous mixtures of nitrogen with both argon and xenon by stopping of 210 Po-alpha particles. In the absence of a wavelength shifter, the N 2 -Ar mixtures gave a maximum pulse height at a ratio of nitrogen to argon partial pressures rsub(N 2 /Ar) approximately =0.2. However, when using the wavelength shifter diphenyl stilbene (DPS), the measured light output was much larger at lower values of rsub(N 2 /Ar), whereas for rsub(N 2 /Ar)>0.2 pulse height and energy resolution of the studied N 2 -Ar mixtures were roughly indentical with and without DPS. The N 2 -Xe gas mixtures exhibited a similar dependence of pulse height and energy resolution to that of the N 2 -Ar mixtures employing DPS, but the pulse height was larger by a factor of about 7. A 40 atm 50% N 2 -50% Xe gas scintillator showed an energy resolution ΔE/E=0.25, while an 80 atm 75% N 2 -25% Xe scintillator gave ΔE/E=0.6. The pulse height from the 80 atm N 2 -Xe scintillator was smaller by a factor of about 240 than the pulse height from a 20 atm pure Xe gas scintillator, but larger by a factor of about 20 than the pulse height from a 75 atm pure N 2 gas scintillator. The N 2 -Xe mixtures showed a remarkable increase of light output as the temperature of the gas was descreased. (Auth.)

  18. High Resolution PET with 250 micrometer LSO Detectors and Adaptive Zoom

    International Nuclear Information System (INIS)

    Cherry, Simon R.; Qi, Jinyi

    2012-01-01

    There have been impressive improvements in the performance of small-animal positron emission tomography (PET) systems since their first development in the mid 1990s, both in terms of spatial resolution and sensitivity, which have directly contributed to the increasing adoption of this technology for a wide range of biomedical applications. Nonetheless, current systems still are largely dominated by the size of the scintillator elements used in the detector. Our research predicts that developing scintillator arrays with an element size of 250 (micro)m or smaller will lead to an image resolution of 500 (micro)m when using 18F- or 64Cu-labeled radiotracers, giving a factor of 4-8 improvement in volumetric resolution over the highest resolution research systems currently in existence. This proposal had two main objectives: (i) To develop and evaluate much higher resolution and efficiency scintillator arrays that can be used in the future as the basis for detectors in a small-animal PET scanner where the spatial resolution is dominated by decay and interaction physics rather than detector size. (ii) To optimize one such high resolution, high sensitivity detector and adaptively integrate it into the existing microPET II small animal PET scanner as a 'zoom-in' detector that provides higher spatial resolution and sensitivity in a limited region close to the detector face. The knowledge gained from this project will provide valuable information for building future PET systems with a complete ring of very high-resolution detector arrays and also lay the foundations for utilizing high-resolution detectors in combination with existing PET systems for localized high-resolution imaging.

  19. Scintillators for positron emission tomography

    International Nuclear Information System (INIS)

    Moses, W.W.; Derenzo, S.E.

    1995-09-01

    Like most applications that utilize scintillators for gamma detection, Positron Emission Tomography (PET) desires materials with high light output, short decay time, and excellent stopping power that are also inexpensive, mechanically rugged, and chemically inert. Realizing that this ''ultimate'' scintillator may not exist, this paper evaluates the relative importance of these qualities and describes their impact on the imaging performance of PET. The most important PET scintillator quality is the ability to absorb 511 keV photons in a small volume, which affects the spatial resolution of the camera. The dominant factor is a short attenuation length (≤ 1.5 cm is required), although a high photoelectric fraction is also important (> 30% is desired). The next most important quality is a short decay time, which affects both the dead time and the coincidence timing resolution. Detection rates for single 511 keV photons can be extremely high, so decay times ≤ 500 ns are essential to avoid dead time losses. In addition, positron annihilations are identified by time coincidence so ≤5 ns fwhm coincidence pair timing resolution is required to identify events with narrow coincidence windows, reducing contamination due to accidental coincidences. Current trends in PET cameras are toward septaless, ''fully-3D'' cameras, which have significantly higher count rates than conventional 2-D cameras and so place higher demands on scintillator decay time. Light output affects energy resolution, and thus the ability of the camera to identify and reject events where the initial 511 keV photon has undergone Compton scatter in the patient. The scatter to true event fraction is much higher in fully-3D cameras than in 2-D cameras, so future PET cameras would benefit from scintillators with a 511 keV energy resolution < 10--12% fwhm

  20. Evaluation of characteristics of x-ray phosphors and hybrid scintillators

    International Nuclear Information System (INIS)

    Winter, John M. Jr.; Jones, Thomas S.

    1999-01-01

    Glass x-ray scintillators produce very high resolution images but suffer diminished brightness at x-ray energies below about 150 kV. This produces a loss in effective imaging due to the very low light flux, just at energies where many high resolution applications require the maximum image fidelity. Many phosphors produce substantially more light at these energy levels, but lack the resolution needed for critical industrial applications. A family of hybrid scintillators consisting of a scintillating fiber-optic base coupled to a thin coating of a high resolution phosphor is being developed. To facilitate evaluation of these hybrids and to measure their performance compared to other alternatives, a specialized real time x-ray imaging system was constructed and integrated with a microfocus x-ray source. This imaging system is described, and the results of a program to evaluate the brightness, resolution, and contrast sensitivity of a number of glass scintillators, phosphors, and hybrid imaging screens is presented

  1. Energy resolution of a lead scintillating fiber electromagnetic calorimeter

    International Nuclear Information System (INIS)

    Budagov, Yu.; Chirikov-Zorin, I.; Glagolev, V.

    1993-01-01

    A calorimeter module was fabricated using profiled lead plates and scintillating fibers with diameter 1 mm and attenuation length about 80 cm. The absorber-to-fiber volume ratio was 1.17 and the module average radiation length X 0 = 1.05 cm. The energy resolution of the module was investigated using the electron beams of U-70 at Serpukhov and of the SPS at CERN in the energy range 5-70 GeV. The energy resolution at θ = 3 0 (the angle between the fiber axis and the beam direction) may be expressed by the formula σ/E(%) = 13.1/√E ± 1.7. The energy resolution was also simulated by Monte Carlo and good agreement with the experiment has been achieved. 12 refs.; 13 figs.; 4 tabs

  2. Some rules to improve the energy resolution in alpha liquid scintillation with beta rejection

    CERN Document Server

    Aupiais, J; Dacheux, N

    2003-01-01

    Two common scintillating mixtures dedicated to alpha measurements by means of alpha liquid scintillation with pulse shape discrimination were tested: the di-isopropylnaphthalene - based and the toluene-based solvents containing the commercial cocktails Ultima Gold AB trademark and Alphaex trademark. We show the possibility to enhance the resolution up to 200% by using no-water miscible cocktails and by reducing the optical path. Under these conditions, the resolution of about 200 keV can be obtained either by the Tri Carb sup T sup M or by the Perals sup T sup M spectrometers. The time responses, e.g., the time required for a complete energy transfer between the initial interaction alpha particle-solvent and the final fluorescence of the organic scintillator, have been compared. Both cocktails present similar behavior. According to the Foerster theory, about 6-10 ns are required to complete the energy transfer. For both apparatus, the detection limits were determined for alpha emitters. The sensitivity of the...

  3. A comprehensive & systematic study of coincidence time resolution and light yield using scintillators of different size, wrapping and doping

    CERN Document Server

    Auffray, E.; Geraci, F.; Ghezzi, A.; Gundacker, S.; Hillemanns, H.; Jarron, P.; Meyer, T.; Paganoni, M.; Pauwels, K.; Pizzichemi, M.; Lecoq, P.

    2011-01-01

    Over the last years interest in using time-of-flight-based Positron Emission Tomography (TOF-PET) systems has significantly increased. High time resolution in such PET systems is a powerful tool to improve signal to noise ratio and therefore to allow smaller exposure rates for patients as well as faster image reconstruction. Improvement in coincidence time resolution (CTR) in PET systems to the level of 200ps FWHM requires the optimization of all parameters in the photon detection chain influencing the time resolution: crystal, photodetector and readout electronics. After reviewing the factors influencing the time resolution of scintillators, we will present in this paper the light yield and CTR obtained for different scintillator types (LSO:Ce, LYSO:Ce, LGSO:Ce, LSO:Ce:0.4Ca, LuAG:Ce, LuAG:Pr) with different cross-sections, lengths and reflectors. Whereas light yield measurements were made with a classical PMT, all CTR tests were performed with Hamamatsu-MPPCs or SiPMs S10931-050P. The CTR measurements were ...

  4. Performance of high-resolution position-sensitive detectors developed for storage-ring decay experiments

    International Nuclear Information System (INIS)

    Yamaguchi, T.; Suzaki, F.; Izumikawa, T.; Miyazawa, S.; Morimoto, K.; Suzuki, T.; Tokanai, F.; Furuki, H.; Ichihashi, N.; Ichikawa, C.; Kitagawa, A.; Kuboki, T.; Momota, S.; Nagae, D.; Nagashima, M.; Nakamura, Y.; Nishikiori, R.; Niwa, T.; Ohtsubo, T.; Ozawa, A.

    2013-01-01

    Highlights: • Position-sensitive detectors were developed for storage-ring decay spectroscopy. • Fiber scintillation and silicon strip detectors were tested with heavy ion beams. • A new fiber scintillation detector showed an excellent position resolution. • Position and energy detection by silicon strip detectors enable full identification. -- Abstract: As next generation spectroscopic tools, heavy-ion cooler storage rings will be a unique application of highly charged RI beam experiments. Decay spectroscopy of highly charged rare isotopes provides us important information relevant to the stellar conditions, such as for the s- and r-process nucleosynthesis. In-ring decay products of highly charged RI will be momentum-analyzed and reach a position-sensitive detector set-up located outside of the storage orbit. To realize such in-ring decay experiments, we have developed and tested two types of high-resolution position-sensitive detectors: silicon strips and scintillating fibers. The beam test experiments resulted in excellent position resolutions for both detectors, which will be available for future storage-ring experiments

  5. High-efficiency organic glass scintillators

    Science.gov (United States)

    Feng, Patrick L.; Carlson, Joseph S.

    2017-12-19

    A new family of neutron/gamma discriminating scintillators is disclosed that comprises stable organic glasses that may be melt-cast into transparent monoliths. These materials have been shown to provide light yields greater than solution-grown trans-stilbene crystals and efficient PSD capabilities when combined with 0.01 to 0.05% by weight of the total composition of a wavelength-shifting fluorophore. Photoluminescence measurements reveal fluorescence quantum yields that are 2 to 5 times greater than conventional plastic or liquid scintillator matrices, which accounts for the superior light yield of these glasses. The unique combination of high scintillation light-yields, efficient neutron/gamma PSD, and straightforward scale-up via melt-casting distinguishes the developed organic glasses from existing scintillators.

  6. 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.

  7. A user's guide to scintillation

    International Nuclear Information System (INIS)

    Hewish, A.

    1989-01-01

    During the past four decades scintillation methods have been used for remote-sensing distant plasmas and for providing high angular resolution in radioastronomy. This brief review illustrates some of the techniques employed and explains the underlying theory in simple physical terms; it is not intended to be a complete survey of all applications of scintillation. (author)

  8. Current trends in scintillator detectors and materials

    International Nuclear Information System (INIS)

    Moses, W.W.

    2002-01-01

    The last decade has seen a renaissance in inorganic scintillator development for gamma ray detection. Lead tungstate (PbWO 4 ) has been developed for high-energy physics experiments, and possesses exceptionally high density and radiation hardness, albeit with low luminous efficiency. Lutetium orthosilicate or LSO (Lu 2 SiO 5 :Ce) possesses a unique combination of high luminous efficiency, high density, and reasonably short decay time, and is now incorporated in commercial positron emission tomography cameras. There have been advances in understanding the fundamental mechanisms that limit energy resolution, and several recently discovered materials (such as LaBr 3 :Ce) possess energy resolution that approaches that of direct solid state detectors. Finally, there are indications that a neglected class of scintillator materials that exhibit near band-edge fluorescence could provide scintillators with sub-nanosecond decay times and high luminescent efficiency

  9. Experimental study of high-energy resolution lead/scintillating fiber calorimetry in the 600-1200 MeV energy region

    International Nuclear Information System (INIS)

    Bellini, V.; Bianco, S.; Capogni, M.; Casano, L.; D'Angelo, A.; Fabbri, F.L.; Ghio, F.; Giardoni, M.; Girolami, B.; Hu, L.; Levi Sandri, P.; Moricciani, D.; Nobili, G.; Passamonti, L.; Russo, V.; Sarwar, S.; Schaerf, C.

    1997-01-01

    An experimental investigation has been carried out on the properties of electromagnetic shower detectors, composed of a uniform array of plastic scintillating fibers and lead (50:35 by volume ratio) for photons in the energy range 600-1200 MeV. When the photon's incidence angle to the fiber axis is within ±2 circle an energy resolution of σ E /E(%)=5.12/√(E[GeV])+1.71 has been observed. (orig.)

  10. Plastic scintillation dosimetry: Optimal selection of scintillating fibers and scintillators

    International Nuclear Information System (INIS)

    Archambault, Louis; Arsenault, Jean; Gingras, Luc; Sam Beddar, A.; Roy, Rene; Beaulieu, Luc

    2005-01-01

    Scintillation dosimetry is a promising avenue for evaluating dose patterns delivered by intensity-modulated radiation therapy plans or for the small fields involved in stereotactic radiosurgery. However, the increase in signal has been the goal for many authors. In this paper, a comparison is made between plastic scintillating fibers and plastic scintillator. The collection of scintillation light was measured experimentally for four commercial models of scintillating fibers (BCF-12, BCF-60, SCSF-78, SCSF-3HF) and two models of plastic scintillators (BC-400, BC-408). The emission spectra of all six scintillators were obtained by using an optical spectrum analyzer and they were compared with theoretical behavior. For scintillation in the blue region, the signal intensity of a singly clad scintillating fiber (BCF-12) was 120% of that of the plastic scintillator (BC-400). For the multiclad fiber (SCSF-78), the signal reached 144% of that of the plastic scintillator. The intensity of the green scintillating fibers was lower than that of the plastic scintillator: 47% for the singly clad fiber (BCF-60) and 77% for the multiclad fiber (SCSF-3HF). The collected light was studied as a function of the scintillator length and radius for a cylindrical probe. We found that symmetric detectors with nearly the same spatial resolution in each direction (2 mm in diameter by 3 mm in length) could be made with a signal equivalent to those of the more commonly used asymmetric scintillators. With augmentation of the signal-to-noise ratio in consideration, this paper presents a series of comparisons that should provide insight into selection of a scintillator type and volume for development of a medical dosimeter

  11. High Efficiency, Low Cost Scintillators for PET

    International Nuclear Information System (INIS)

    Kanai Shah

    2007-01-01

    Inorganic scintillation detectors coupled to PMTs are an important element of medical imaging applications such as positron emission tomography (PET). Performance as well as cost of these systems is limited by the properties of the scintillation detectors available at present. The Phase I project was aimed at demonstrating the feasibility of producing high performance scintillators using a low cost fabrication approach. Samples of these scintillators were produced and their performance was evaluated. Overall, the Phase I effort was very successful. The Phase II project will be aimed at advancing the new scintillation technology for PET. Large samples of the new scintillators will be produced and their performance will be evaluated. PET modules based on the new scintillators will also be built and characterized

  12. A primary scintillation gated high pressure position sensitive gas scintillation proportional counter (HPGSPC) for applications to x-ray astronomy

    International Nuclear Information System (INIS)

    Giarrusso, S.; Manzo, G.; Re, S.

    1985-01-01

    The authors describe a new instrument for x-ray astronomy. The instrument, based on a high pressure (5 atm.), xenon filled, position sensitive Gas Scintillation Proportional counter (HPGSPC) is expected to feature an energy resolution better than 4% at 60 keV, an angular resolution of approximately 20 arc-minutes over the full energy range (4 to 100 keV) and a field of view (FOV) of up to 30x30 degrees. A prototype flight unit of the gas cell on which the instrument is based is presently under technological development in the framework of the SAX project

  13. Time resolution of the plastic scintillator strips with matrix photomultiplier readout for J-PET tomograph

    Science.gov (United States)

    Moskal, P.; Rundel, O.; Alfs, D.; Bednarski, T.; Białas, P.; Czerwiński, E.; Gajos, A.; Giergiel, K.; Gorgol, M.; Jasińska, B.; Kamińska, D.; Kapłon, Ł.; Korcyl, G.; Kowalski, P.; Kozik, T.; Krzemień, W.; Kubicz, E.; Niedźwiecki, Sz; Pałka, M.; Raczyński, L.; Rudy, Z.; Sharma, N. G.; Słomski, A.; Silarski, M.; Strzelecki, A.; Wieczorek, A.; Wiślicki, W.; Witkowski, P.; Zieliński, M.; Zoń, N.

    2016-03-01

    Recent tests of a single module of the Jagiellonian Positron Emission Tomography system (J-PET) consisting of 30 cm long plastic scintillator strips have proven its applicability for the detection of annihilation quanta (0.511 MeV) with a coincidence resolving time (CRT) of 0.266 ns. The achieved resolution is almost by a factor of two better with respect to the current TOF-PET detectors and it can still be improved since, as it is shown in this article, the intrinsic limit of time resolution for the determination of time of the interaction of 0.511 MeV gamma quanta in plastic scintillators is much lower. As the major point of the article, a method allowing to record timestamps of several photons, at two ends of the scintillator strip, by means of matrix of silicon photomultipliers (SiPM) is introduced. As a result of simulations, conducted with the number of SiPM varying from 4 to 42, it is shown that the improvement of timing resolution saturates with the growing number of photomultipliers, and that the 2× 5 configuration at two ends allowing to read twenty timestamps, constitutes an optimal solution. The conducted simulations accounted for the emission time distribution, photon transport and absorption inside the scintillator, as well as quantum efficiency and transit time spread of photosensors, and were checked based on the experimental results. Application of the 2× 5 matrix of SiPM allows for achieving the coincidence resolving time in positron emission tomography of ≈ 0.170 ns for 15 cm axial field-of-view (AFOV) and ≈ 0.365 ns for 100 cm AFOV. The results open perspectives for construction of a cost-effective TOF-PET scanner with significantly better TOF resolution and larger AFOV with respect to the current TOF-PET modalities.

  14. Liquid scintillation solution

    International Nuclear Information System (INIS)

    Long, E.C.

    1976-01-01

    The invention deals with a liquid scintillation solution which contains 1) a scintillation solvent (toluol), 2) a primary scintillation solute (PPO), 3) a secondary scintillation solute (dimethyl POPOP), 4) several surfactants (iso-octyl-phenol polyethoxy-ethanol and sodium di-hexyl sulfosuccinate) essentially different from one another and 5) a filter resolution and/or transparent-making agent (cyclic ether, especially tetrahydrofuran). (HP) [de

  15. New DOI identification approach for high-resolution PET detectors

    International Nuclear Information System (INIS)

    Choghadi, Amin; Takahashi, Hiroyuki; Shimazoe, Kenji

    2016-01-01

    Depth-of-interaction (DOI) Identification in positron emission tomography (PET) detectors is getting importance as it improves spatial resolution in both conventional and time-of-flight (TOF) PET, and coincidence time resolution (CTR) in TOF-PET. In both prototypes, spatial resolution is affected by parallax error caused by length of scintillator crystals. This long length also contributes substantial timing uncertainty to the time resolution of TOF-PET. Through DOI identification, both parallax error and the timing uncertainty caused by the length of crystal can be resolved. In this work, a novel approach to estimate DOI was investigated, enjoying the interference of absorbance spectrum of scintillator crystals with their emission spectrum. Because the absorption length is close to zero for shorter wavelengths of crystal emission spectrum, the counts in this range of spectrum highly depend on DOI; that is, higher counts corresponds to deeper interactions. The ratio of counts in this range to the total counts is a good measure to estimate DOI. In order to extract such ratio, two photodetectors for each crystal are used and an optical filter is mounted only on top of one of them. The ratio of filtered output to non-filtered output can be utilized as DOI estimator. For a 2×2×20 mm 3 GAGG:Ce scintillator, 8-mm DOI resolution achieved in our simulations. (author)

  16. Collimated trans-axial tomographic scintillation camera

    International Nuclear Information System (INIS)

    1980-01-01

    The objects of this invention are first to reduce the time required to obtain statistically significant data in trans-axial tomographic radioisotope scanning using a scintillation camera. Secondly, to provide a scintillation camera system to increase the rate of acceptance of radioactive events to contribute to the positional information obtainable from a known radiation source without sacrificing spatial resolution. Thirdly to reduce the scanning time without loss of image clarity. The system described comprises a scintillation camera detector, means for moving this in orbit about a cranial-caudal axis relative to a patient and a collimator having septa defining apertures such that gamma rays perpendicular to the axis are admitted with high spatial resolution, parallel to the axis with low resolution. The septa may be made of strips of lead. Detailed descriptions are given. (U.K.)

  17. The frequency analysis particle resolution technique of 6LiI(Eu) scintillation detector

    International Nuclear Information System (INIS)

    Duan Shaojie

    1995-01-01

    To measure the distribution and rate of tritium production by neutron in a 6 LiD sphere, the 6 LiI(Eu) scintillation detector was used. In the measurement, the frequency analysis particle resolution technique was used. The experiment was completed perfectly

  18. Experimental measurement of a high resolution CMOS detector coupled to CsI scintillators under X-ray radiation

    International Nuclear Information System (INIS)

    Michail, C.; Valais, I.; Seferis, I.; Kalyvas, N.; Fountos, G.; Kandarakis, I.

    2015-01-01

    The purpose of the present study was to assess the information content of structured CsI:Tl scintillating screens, specially treated to be compatible to a CMOS digital imaging optical sensor, in terms of the information capacity (IC), based on Shannon's mathematical communication theory. IC was assessed after the experimental determination of the Modulation Transfer Function (MTF) and the Normalized Noise Power Spectrum (NNPS) in the mammography and general radiography energy range. The CMOS sensor was coupled to three columnar CsI:Tl scintillator screens obtained from the same manufacturer with thicknesses of 130, 140 and 170 μm respectively, which were placed in direct contact with the optical sensor. The MTF was measured using the slanted-edge method while NNPS was determined by 2D Fourier transforming of uniformly exposed images. Both parameters were assessed by irradiation under the mammographic W/Rh (130, 140 and 170 μm CsI screens) and the RQA-5 (140 and 170 μm CsI screens) (IEC 62220-1) beam qualities. The detector response function was linear for the exposure range under investigation. At 70 kVp, under the RQA-5 conditions IC values were found to range between 2229 and 2340 bits/mm 2 . At 28 kVp the corresponding IC values were found to range between 2262 and 2968 bits/mm 2 . The information content of CsI:Tl scintillating screens in combination to the high resolution CMOS sensor, investigated in the present study, where found optimized for use in digital mammography imaging systems. - Highlights: • Three structured CsI:Tl screens (130,140 & 170 um) were coupled to a CMOS sensor. • MTF of the CsI/CMOS was higher than GOS:Tb and CsI based digital imaging systems. • IC of CsI:Tl/CMOS was found optimized for use in digital mammography systems

  19. Investigation of high resolution compact gamma camera module based on a continuous scintillation crystal using a novel charge division readout method

    International Nuclear Information System (INIS)

    Dai Qiusheng; Zhao Cuilan; Qi Yujin; Zhang Hualin

    2010-01-01

    The objective of this study is to investigate a high performance and lower cost compact gamma camera module for a multi-head small animal SPECT system. A compact camera module was developed using a thin Lutetium Oxyorthosilicate (LSO) scintillation crystal slice coupled to a Hamamatsu H8500 position sensitive photomultiplier tube (PSPMT). A two-stage charge division readout board based on a novel subtractive resistive readout with a truncated center-of-gravity (TCOG) positioning method was developed for the camera. The performance of the camera was evaluated using a flood 99m Tc source with a four-quadrant bar-mask phantom. The preliminary experimental results show that the image shrinkage problem associated with the conventional resistive readout can be effectively overcome by the novel subtractive resistive readout with an appropriate fraction subtraction factor. The response output area (ROA) of the camera shown in the flood image was improved up to 34%, and an intrinsic spatial resolution better than 2 mm of detector was achieved. In conclusion, the utilization of a continuous scintillation crystal and a flat-panel PSPMT equipped with a novel subtractive resistive readout is a feasible approach for developing a high performance and lower cost compact gamma camera. (authors)

  20. Eu-activated fluorochlorozirconate glass-ceramic scintillators

    International Nuclear Information System (INIS)

    Johnson, J. A.; Schweizer, S.; Henke, B.; Chen, G.; Woodford, J.; Newman, P. J.; MacFarlane, D. R.

    2006-01-01

    Rare-earth-doped fluorochlorozirconate (FCZ) glass-ceramic materials have been developed as scintillators and their properties investigated as a function of dopant level. The paper presents the relative scintillation efficiency in comparison to single-crystal cadmium tungstate, the scintillation intensity as a function of x-ray intensity and x-ray energy, and the spatial resolution (modulation transfer function). Images obtained with the FCZ glass-ceramic scintillator and with cadmium tungstate are also presented. Comparison shows that the image quality obtained using the glass ceramic is close to that from cadmium tungstate. Therefore, the glass-ceramic scintillator could be used as an alternative material for image formation resulting from scintillation. Other inorganic scintillators such as single crystals or polycrystalline films have limitations in resolution or size, but the transparent glass-ceramic can be scaled to any shape or size with excellent resolution

  1. Scintillator Evaluation for High-Energy X-Ray Diagnostics

    International Nuclear Information System (INIS)

    Lutz, S. S.; Baker, S. A.

    2001-01-01

    This report presents results derived from a digital radiography study performed using x-rays from a 2.3 MeV, rod-pinch diode. Detailed is a parameter study of cerium-doped lutetium ortho-silicate (LSO) scintillator thickness, as it relates to system resolution and detection quantum efficiency (DQE). Additionally, the detection statistics of LSO were compared with that of CsI(Tl). As a result of this study we found the LSO scintillator with a thickness of 3 mm to yield the highest system DQE over the range of spatial frequencies from 0.75 to 2.5 mm -1

  2. Scintillating fibre detectors using position-sensitive photomultipliers

    International Nuclear Information System (INIS)

    Agoritsas, V.; Bergdolt, A.M.; Bing, O.; Bravar, A.; Ditta, J.; Drevenak, R.

    1995-01-01

    Scintillating fibre technology has made substantial progress, and has demonstrated great potential for fast tracking and triggering in high luminosity experiments in Particle Physics. Some recent issues of the RD-17 project at CERN are presented for fast and precise readout of scintillating fibre arrays, as well as for upgrade of position-sensitive photomultipliers. Excellent matching of the scintillating fibre and the position-sensitive photomultiplier, in particular in time characteristics, allowed to achieve excellent detector performances, typically a spatial resolution of ∼ 125 μm with time resolution better than 1 ns and detection efficiency greater than 95%. (author)10 refs.; 25 figs.; 1 tab

  3. Construction and response of a highly granular scintillator-based electromagnetic calorimeter

    Science.gov (United States)

    Repond, J.; Xia, L.; Eigen, G.; Price, T.; Watson, N. K.; Winter, A.; Thomson, M. A.; Cârloganu, C.; Blazey, G. C.; Dyshkant, A.; Francis, K.; Zutshi, V.; Gadow, K.; Göttlicher, P.; Hartbrich, O.; Kotera, K.; Krivan, F.; Krüger, K.; Lu, S.; Lutz, B.; Reinecke, M.; Sefkow, F.; Sudo, Y.; Tran, H. L.; Kaplan, A.; Schultz-Coulon, H.-Ch.; Bilki, B.; Northacker, D.; Onel, Y.; Wilson, G. W.; Kawagoe, K.; Sekiya, I.; Suehara, T.; Yamashiro, H.; Yoshioka, T.; Alamillo, E. Calvo; Fouz, M. C.; Marin, J.; Navarrete, J.; Pelayo, J. Puerta; Verdugo, A.; Chadeeva, M.; Danilov, M.; Gabriel, M.; Goecke, P.; Graf, C.; Israeli, Y.; Kolk, N. Van Der; Simon, F.; Szalay, M.; Windel, H.; Bilokin, S.; Bonis, J.; Pöschl, R.; Thiebault, A.; Richard, F.; Zerwas, D.; Balagura, V.; Boudry, V.; Brient, J.-C.; Cornat, R.; Cvach, J.; Janata, M.; Kovalcuk, M.; Kvasnicka, J.; Polak, I.; Smolik, J.; Vrba, V.; Zalesak, J.; Zuklin, J.; Choi, W.; Kotera, K.; Nishiyama, M.; Sakuma, T.; Takeshita, T.; Tozuka, S.; Tsubokawa, T.; Uozumi, S.; Jeans, D.; Ootani, W.; Liu, L.; Chang, S.; Khan, A.; Kim, D. H.; Kong, D. J.; Oh, Y. D.; Ikuno, T.; Sudo, Y.; Takahashi, Y.; Götze, M.; Calice Collaboration

    2018-04-01

    A highly granular electromagnetic calorimeter with scintillator strip readout is being developed for future linear collider experiments. A prototype of 21.5 X0 depth and 180 × 180mm2 transverse dimensions was constructed, consisting of 2160 individually read out 10 × 45 × 3mm3 scintillator strips. This prototype was tested using electrons of 2-32 GeV at the Fermilab Test Beam Facility in 2009. Deviations from linear energy response were less than 1.1%, and the intrinsic energy resolution was determined to be (12 . 5 ± 0 . 1(stat.) ± 0 . 4(syst.)) % /√{ E [ GeV ] } ⊕(1.2 ± 0.1 (stat.)-0.7+0.6 (syst.)) %, where the uncertainties correspond to statistical and systematic sources, respectively.

  4. High efficiency scintillation detectors

    International Nuclear Information System (INIS)

    Noakes, J.E.

    1976-01-01

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

  5. Performance of a highly segmented scintillating fibres electromagnetic calorimeter

    International Nuclear Information System (INIS)

    Asmone, A.; Bertino, M.; Bini, C.; De Zorzi, G.; Diambrini Palazzi, G.; Di Cosimo, G.; Di Domenico, A.; Garufi, F.; Gauzzi, P.; Zanello, D.

    1993-01-01

    A prototype of scintillating fibres electromagnetic calorimeter has been constructed and tested with 2, 4 and 8 GeV electron beams at the CERN PS. The calorimeter modules consist of a Bi-Pb-Sn alloy and scintillating fibres. The fibres are parallel to the modules longer axis, and nearly parallel to the incident electrons direction. The calorimeter has two different segmentation regions of 24x24 mm 2 and 8x24 mm 2 cross area respectively. Results on energy and impact point space resolution are obtained and compared for the two different granularities. (orig.)

  6. Testing and simulation of silicon photomultiplier readouts for scintillators in high-energy astronomy and solar physics

    Science.gov (United States)

    Bloser, P. F.; Legere, J. S.; Bancroft, C. M.; Jablonski, L. F.; Wurtz, J. R.; Ertley, C. D.; McConnell, M. L.; Ryan, J. M.

    2014-11-01

    Space-based gamma-ray detectors for high-energy astronomy and solar physics face severe constraints on mass, volume, and power, and must endure harsh launch conditions and operating environments. Historically, such instruments have usually been based on scintillator materials due to their relatively low cost, inherent ruggedness, high stopping power, and radiation hardness. New scintillator materials, such as LaBr3:Ce, feature improved energy and timing performance, making them attractive for future astronomy and solar physics space missions in an era of tightly constrained budgets. Despite this promise, the use of scintillators in space remains constrained by the volume, mass, power, and fragility of the associated light readout device, typically a vacuum photomultiplier tube (PMT). In recent years, silicon photomultipliers (SiPMs) have emerged as promising alternative light readout devices that offer gains and quantum efficiencies similar to those of PMTs, but with greatly reduced mass and volume, high ruggedness, low voltage requirements, and no sensitivity to magnetic fields. In order for SiPMs to replace PMTs in space-based instruments, however, it must be shown that they can provide comparable performance, and that their inherent temperature sensitivity can be corrected for. To this end, we have performed extensive testing and modeling of a small gamma-ray spectrometer composed of a 6 mm×6 mm SiPM coupled to a 6 mm×6 mm ×10 mm LaBr3:Ce crystal. A custom readout board monitors the temperature and adjusts the bias voltage to compensate for gain variations. We record an energy resolution of 5.7% (FWHM) at 662 keV at room temperature. We have also performed simulations of the scintillation process and optical light collection using Geant4, and of the SiPM response using the GosSiP package. The simulated energy resolution is in good agreement with the data from 22 keV to 662 keV. Above ~1 MeV, however, the measured energy resolution is systematically worse than

  7. Testing and simulation of silicon photomultiplier readouts for scintillators in high-energy astronomy and solar physics

    International Nuclear Information System (INIS)

    Bloser, P.F.; Legere, J.S.; Bancroft, C.M.; Jablonski, L.F.; Wurtz, J.R.; Ertley, C.D.; McConnell, M.L.; Ryan, J.M.

    2014-01-01

    Space-based gamma-ray detectors for high-energy astronomy and solar physics face severe constraints on mass, volume, and power, and must endure harsh launch conditions and operating environments. Historically, such instruments have usually been based on scintillator materials due to their relatively low cost, inherent ruggedness, high stopping power, and radiation hardness. New scintillator materials, such as LaBr 3 :Ce, feature improved energy and timing performance, making them attractive for future astronomy and solar physics space missions in an era of tightly constrained budgets. Despite this promise, the use of scintillators in space remains constrained by the volume, mass, power, and fragility of the associated light readout device, typically a vacuum photomultiplier tube (PMT). In recent years, silicon photomultipliers (SiPMs) have emerged as promising alternative light readout devices that offer gains and quantum efficiencies similar to those of PMTs, but with greatly reduced mass and volume, high ruggedness, low voltage requirements, and no sensitivity to magnetic fields. In order for SiPMs to replace PMTs in space-based instruments, however, it must be shown that they can provide comparable performance, and that their inherent temperature sensitivity can be corrected for. To this end, we have performed extensive testing and modeling of a small gamma-ray spectrometer composed of a 6 mm×6 mm SiPM coupled to a 6 mm×6 mm ×10 mm LaBr 3 :Ce crystal. A custom readout board monitors the temperature and adjusts the bias voltage to compensate for gain variations. We record an energy resolution of 5.7% (FWHM) at 662 keV at room temperature. We have also performed simulations of the scintillation process and optical light collection using Geant4, and of the SiPM response using the GosSiP package. The simulated energy resolution is in good agreement with the data from 22 keV to 662 keV. Above ∼1 MeV, however, the measured energy resolution is systematically

  8. Testing and simulation of silicon photomultiplier readouts for scintillators in high-energy astronomy and solar physics

    Energy Technology Data Exchange (ETDEWEB)

    Bloser, P.F., E-mail: Peter.Bloser@unh.edu; Legere, J.S.; Bancroft, C.M.; Jablonski, L.F.; Wurtz, J.R.; Ertley, C.D.; McConnell, M.L.; Ryan, J.M.

    2014-11-01

    Space-based gamma-ray detectors for high-energy astronomy and solar physics face severe constraints on mass, volume, and power, and must endure harsh launch conditions and operating environments. Historically, such instruments have usually been based on scintillator materials due to their relatively low cost, inherent ruggedness, high stopping power, and radiation hardness. New scintillator materials, such as LaBr{sub 3}:Ce, feature improved energy and timing performance, making them attractive for future astronomy and solar physics space missions in an era of tightly constrained budgets. Despite this promise, the use of scintillators in space remains constrained by the volume, mass, power, and fragility of the associated light readout device, typically a vacuum photomultiplier tube (PMT). In recent years, silicon photomultipliers (SiPMs) have emerged as promising alternative light readout devices that offer gains and quantum efficiencies similar to those of PMTs, but with greatly reduced mass and volume, high ruggedness, low voltage requirements, and no sensitivity to magnetic fields. In order for SiPMs to replace PMTs in space-based instruments, however, it must be shown that they can provide comparable performance, and that their inherent temperature sensitivity can be corrected for. To this end, we have performed extensive testing and modeling of a small gamma-ray spectrometer composed of a 6 mm×6 mm SiPM coupled to a 6 mm×6 mm ×10 mm LaBr{sub 3}:Ce crystal. A custom readout board monitors the temperature and adjusts the bias voltage to compensate for gain variations. We record an energy resolution of 5.7% (FWHM) at 662 keV at room temperature. We have also performed simulations of the scintillation process and optical light collection using Geant4, and of the SiPM response using the GosSiP package. The simulated energy resolution is in good agreement with the data from 22 keV to 662 keV. Above ∼1 MeV, however, the measured energy resolution is

  9. Development of high-resolution detector module with depth of interaction identification for positron emission tomography

    International Nuclear Information System (INIS)

    Niknejad, Tahereh; Pizzichemi, Marco; Stringhini, Gianluca; Auffray, Etiennette; Bugalho, Ricardo; Da Silva, Jose Carlos; Di Francesco, Agostino; Ferramacho, Luis; Lecoq, Paul; Leong, Carlos; Paganoni, Marco; Rolo, Manuel; Silva, Rui; Silveira, Miguel; Tavernier, Stefaan; Varela, Joao; Zorraquino, Carlos

    2017-01-01

    We have developed a Time-of-flight high resolution and commercially viable detector module for the application in small PET scanners. A new approach to depth of interaction (DOI) encoding with low complexity for a pixelated crystal array using a single side readout and 4-to-1 coupling between scintillators and photodetectors was investigated. In this method the DOI information is estimated using the light sharing technique. The detector module is a 1.53×1.53×15 mm"3 matrix of 8×8 LYSO scintillator with lateral surfaces optically depolished separated by reflective foils. The crystal array is optically coupled to 4×4 silicon photomultipliers (SiPM) array and readout by a high performance front-end ASIC with TDC capability (50 ps time binning). The results show an excellent crystal identification for all the scintillators in the matrix, a timing resolution of 530 ps, an average DOI resolution of 5.17 mm FWHM and an average energy resolution of 18.29% FWHM. - Highlights: • A new method for DOI encoding for PET detectors based on light sharing is proposed. • A prototype module with LYSO scintillator matrix coupled to SiPMs array is produced. • The module has one side readout and 4-to-1 coupling between scintillators and SiPMs. • A compact TOF front-end ASIC is used. • Excellent performances are shown by the prototype module.

  10. Development of high-resolution detector module with depth of interaction identification for positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Niknejad, Tahereh, E-mail: tniknejad@lip.pt [Laboratory of Instrumentation and Experimental Particles Physics, Lisbon (Portugal); Pizzichemi, Marco [University of Milano-Bicocca (Italy); Stringhini, Gianluca [University of Milano-Bicocca (Italy); CERN, Geneve (Switzerland); Auffray, Etiennette [CERN, Geneve (Switzerland); Bugalho, Ricardo; Da Silva, Jose Carlos; Di Francesco, Agostino [Laboratory of Instrumentation and Experimental Particles Physics, Lisbon (Portugal); Ferramacho, Luis [PETsys Electronics, Oeiras (Portugal); Lecoq, Paul [CERN, Geneve (Switzerland); Leong, Carlos [PETsys Electronics, Oeiras (Portugal); Paganoni, Marco [University of Milano-Bicocca (Italy); Rolo, Manuel [Laboratory of Instrumentation and Experimental Particles Physics, Lisbon (Portugal); INFN, Turin (Italy); Silva, Rui [Laboratory of Instrumentation and Experimental Particles Physics, Lisbon (Portugal); Silveira, Miguel [PETsys Electronics, Oeiras (Portugal); Tavernier, Stefaan [PETsys Electronics, Oeiras (Portugal); Vrije Universiteit Brussel (Belgium); Varela, Joao [Laboratory of Instrumentation and Experimental Particles Physics, Lisbon (Portugal); CERN, Geneve (Switzerland); Zorraquino, Carlos [Biomedical Image Technologies Lab, Universidad Politécnica de Madrid (Spain); CIBER-BBN, Universidad Politécnica de Madrid (Spain)

    2017-02-11

    We have developed a Time-of-flight high resolution and commercially viable detector module for the application in small PET scanners. A new approach to depth of interaction (DOI) encoding with low complexity for a pixelated crystal array using a single side readout and 4-to-1 coupling between scintillators and photodetectors was investigated. In this method the DOI information is estimated using the light sharing technique. The detector module is a 1.53×1.53×15 mm{sup 3} matrix of 8×8 LYSO scintillator with lateral surfaces optically depolished separated by reflective foils. The crystal array is optically coupled to 4×4 silicon photomultipliers (SiPM) array and readout by a high performance front-end ASIC with TDC capability (50 ps time binning). The results show an excellent crystal identification for all the scintillators in the matrix, a timing resolution of 530 ps, an average DOI resolution of 5.17 mm FWHM and an average energy resolution of 18.29% FWHM. - Highlights: • A new method for DOI encoding for PET detectors based on light sharing is proposed. • A prototype module with LYSO scintillator matrix coupled to SiPMs array is produced. • The module has one side readout and 4-to-1 coupling between scintillators and SiPMs. • A compact TOF front-end ASIC is used. • Excellent performances are shown by the prototype module.

  11. Uranium-scintillator device

    International Nuclear Information System (INIS)

    Smith, S.D.

    1979-01-01

    The calorimeter subgroup of the 1977 ISABELLE Summer Workshop strongly recommended investigation of the uranium-scintillator device because of its several attractive features: (1) increased resolution for hadronic energy, (2) fast time response, (3) high density (i.e., 16 cm of calorimeter per interaction length), and, in comparison with uranium--liquid argon detectors, (4) ease of construction, (5) simple electronics, and (6) lower cost. The AFM group at the CERN ISR became interested in such a calorimeter for substantially the same reasons, and in the fall of 1977 carried out tests on a uranium-scintillator (U-Sc) calorimeter with the same uranium plates used in their 1974 studies of the uranium--liquid argon (U-LA) calorimeter. The chief disadvantage of the scintillator test was that the uranium plates were too small to fully contain the hadronic showers. However, since the scintillator and liquid argon tests were made with the plates, direct comparison of the two types of devices could be made

  12. Timing resolution improvement using DOI information in a four-layer scintillation detector for TOF-PET

    Energy Technology Data Exchange (ETDEWEB)

    Shibuya, Kengo [jPET Project Team, Molecular Imaging Center, National Institute of Radiological Sciences, Anagawa 4-9-1, Inage-ku, Chiba 263-0024 (Japan)], E-mail: shibuken@gakushikai.jp; Nishikido, Fumihiko [jPET Project Team, Molecular Imaging Center, National Institute of Radiological Sciences, Anagawa 4-9-1, Inage-ku, Chiba 263-0024 (Japan); Tsuda, Tomoaki [Technology Research Laboratory, Shimadzu Corporation, Hikaridai 3-9-4, Seika-cho, Kyoto 619-0237 (Japan); Kobayashi, Tetsuya [Department of Medical System Engineering, Graduate School of Engineering, Chiba University, Yayoi 1-33, Inage-ku, Chiba 263-8522 (Japan); Lam, Chihfung; Yamaya, Taiga; Yoshida, Eiji; Inadama, Naoko; Murayama, Hideo [jPET Project Team, Molecular Imaging Center, National Institute of Radiological Sciences, Anagawa 4-9-1, Inage-ku, Chiba 263-0024 (Japan)

    2008-08-11

    Depth-of-interaction (DOI) detectors are considered to be advantageous for time-of-flight positron emission tomography (TOF-PET) because they can correct timing errors arising in the scintillation crystals due to a propagation speed difference between annihilation radiation and scintillation photons. We experimentally measured this timing error, using our four-layer DOI encoding method. The upper layers exhibited the larger timing delays due to the longer path lengths after conversion from annihilation radiation into scintillation photons that traveled by zigzag paths at a speed decreased by a factor of the refractive index (n). The maximum timing delay between the uppermost and the lowermost layers was evaluated as 164 ps when n=1.47. A TOF error correction was demonstrated to improve the timing resolution of the four-layer DOI detector by 10.3%, which would increase the effective sensitivity of the scanner by about 12% comparison with a non-DOI TOF-PET scanner. This is the first step towards combining these two important fields in PET instrumentation, namely DOI and TOF, for the purpose of achieving a higher sensitivity as well as a more uniform spatial resolution.

  13. Role of excitons in the energy resolution of scintillators used for medical imaging

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Jai [School of Engineering and IT, B-purple-12, Faculty of EHS, Charles Darwin University, Darwin NT 0909 (Australia)

    2010-11-01

    Theoretical investigations suggest that the nonproportionality in a scintillator is caused by the high excitation density created within the track of an X-ray or {gamma} ray photon entering in a scintillating crystal. In this paper an analytical expression for the scintillator yield is derived. For the case of BaF{sub 2} scintillator the role of excitons created within the {gamma}-ray track in the scintillator yield is studied. By comparing the results of two theories an analytical expression is also derived for an energy parameter which could otherwise only be determined by fitting the theoretical yield to the experimental data.

  14. Role of excitons in the energy resolution of scintillators used for medical imaging

    International Nuclear Information System (INIS)

    Singh, Jai

    2010-01-01

    Theoretical investigations suggest that the nonproportionality in a scintillator is caused by the high excitation density created within the track of an X-ray or γ ray photon entering in a scintillating crystal. In this paper an analytical expression for the scintillator yield is derived. For the case of BaF 2 scintillator the role of excitons created within the γ-ray track in the scintillator yield is studied. By comparing the results of two theories an analytical expression is also derived for an energy parameter which could otherwise only be determined by fitting the theoretical yield to the experimental data.

  15. Basic performance of Mg co-doped new scintillator used for TOF-DOI-PET systems

    International Nuclear Information System (INIS)

    Kobayashi, Takahiro; Yamamoto, Seiichi; Okumura, Satoshi; Yeom, Jung Yeol; Kamada, Kei; Yoshikawa, Akira

    2017-01-01

    Phoswich depth-of-interaction (DOI) detectors utilizing multiple scintillators with different decay time are a useful device for developing a high spatial resolution, high sensitivity PET scanner. However, in order to apply pulse shape discrimination (PSD), there are not many combinations of scintillators for which phoswich technique can be implemented. Ce doped Gd_3Ga_3Al_2O_1_2 (GFAG) is a recently developed scintillator with a fast decay time. This scintillator is similar to Ce doped Gd_3Al_2Ga_3O_1_2 (GAGG), which is a promising scintillator for PET detector with high light yield. By stacking these scintillators, it may be possible to realize a high spatial resolution and high timing resolution phoswich DOI detector. Such phoswich DOI detector may be applied to time-of-flight (TOF) systems with high timing performance. Therefore, in this study, we tested the basic performance of the new scintillator –GFAG for use in a TOF phoswich detector. The measured decay time of a GFAG element of 2.9 mmx2.9 mmx10 mm in dimension, which was optically coupled to a photomultiplier tube (PMT), was faster (66 ns) than that of same sized GAGG (103 ns). The energy resolution of the GFAG element was 5.7% FWHM which was slightly worse than that of GAGG with 4.9% FWHM for 662 keV gamma photons without saturation correction. Then we assembled the GFAG and the GAGG crystals in the depth direction to form a 20 mm long phoswich element (GFAG/GAGG). By pulse shape analysis, the two types of scintillators were clearly resolved. Measured timing resolution of a pair of opposing GFAG/GAGG phoswich scintillator coupled to Silicon Photomultipliers (Si-PM) was good with coincidence resolving time of 466 ps FWHM. These results indicate that the GFAG combined with GAGG can be a candidate for TOF-DOI-PET systems.

  16. Magnetic fields and scintillator performance

    International Nuclear Information System (INIS)

    Green, D.; Ronzhin, A.; Hagopian, V.

    1995-06-01

    Experimental data have shown that the light output of a scintillator depends on the magnitude of the externally applied magnetic fields, and that this variation can affect the calorimeter calibration and possibly resolution. The goal of the measurements presented here is to study the light yield of scintillators in high magnetic fields in conditions that are similar to those anticipated for the LHC CMS detector. Two independent measurements were performed, the first at Fermilab and the second at the National High Magnetic Field Laboratory at Florida State University

  17. Development of scintillation materials for PET scanners

    CERN Document Server

    Korzhik, Mikhail; Annenkov, Alexander N; Borissevitch, Andrei; Dossovitski, Alexei; Missevitch, Oleg; Lecoq, Paul

    2007-01-01

    The growing demand on PET methodology for a variety of applications ranging from clinical use to fundamental studies triggers research and development of PET scanners providing better spatial resolution and sensitivity. These efforts are primarily focused on the development of advanced PET detector solutions and on the developments of new scintillation materials as well. However Lu containing scintillation materials introduced in the last century such as LSO, LYSO, LuAP, LuYAP crystals still remain the best PET species in spite of the recent developments of bright, fast but relatively low density lanthanum bromide scintillators. At the same time Lu based materials have several drawbacks which are high temperature of crystallization and relatively high cost compared to alkali-halide scintillation materials. Here we describe recent results in the development of new scintillation materials for PET application.

  18. Performance comparison of scintillators for alpha particle detectors

    Energy Technology Data Exchange (ETDEWEB)

    Morishita, Yuki [Graduate School of Medicine, Nagoya University, 1-1-20 Daiko-Minami, Higashi-ku, Nagoya, Aichi 461-8673 (Japan); Japan Atomic Energy Agency, Muramatsu 4-33, Tokai-mura, Ibaraki 319-1194 (Japan); Yamamoto, Seiichi [Graduate School of Medicine, Nagoya University, 1-1-20 Daiko-Minami, Higashi-ku, Nagoya, Aichi 461-8673 (Japan); Izaki, Kenji [Japan Atomic Energy Agency, Muramatsu 4-33, Tokai-mura, Ibaraki 319-1194 (Japan); Kaneko, Junichi H.; Toui, Kohei; Tsubota, Youichi; Higuchi, Mikio [Graduate School of Engineering, Hokkaido University, Kita 13, Nishi 8, Kita-ku, Sapporo, Hokkaido 060-8628 (Japan)

    2014-11-11

    Scintillation detectors for alpha particles are often used in nuclear fuel facilities. Alpha particle detectors have also become important in the research field of radionuclide therapy using alpha emitters. ZnS(Ag) is the most often used scintillator for alpha particle detectors because its light output is high. However, the energy resolution of ZnS(Ag)-based scintillation detectors is poor because they are not transparent. A new ceramic sample, namely the cerium doped Gd{sub 2}Si{sub 2}O{sub 7} (GPS) scintillator, has been tested as alpha particle detector and its performances have been compared to that one of three different scintillating materials: ZnS(Ag), GAGG and a standard plastic scintillator. The different scintillating materials have been coupled to two different photodetectors, namely a photomultiplier tube (PMT) and a Silicon Photo-multiplier (Si-PM): the performances of each detection system have been compared. Promising results as far as the energy resolution performances (10% with PMT and 14% with Si-PM) have been obtained in the case of GPS and GAGG samples. Considering the quantum efficiencies of the photodetectors under test and their relation to the emission wavelength of the different scintillators, the best results were achieved coupling the GPS with the PMT and the GAGG with the Si-PM.

  19. High tracking resolution detectors. Final Technical Report

    International Nuclear Information System (INIS)

    Vasile, Stefan; Li, Zheng

    2010-01-01

    High-resolution tracking detectors based on Active Pixel Sensor (APS) have been valuable tools in Nuclear Physics and High-Energy Physics research, and have contributed to major discoveries. Their integration time, radiation length and readout rate is a limiting factor for the planed luminosity upgrades in nuclear and high-energy physics collider-based experiments. The goal of this program was to demonstrate and develop high-gain, high-resolution tracking detector arrays with faster readout, and shorter radiation length than APS arrays. These arrays may operate as direct charged particle detectors or as readouts of high resolution scintillating fiber arrays. During this program, we developed in CMOS large, high-resolution pixel sensor arrays with integrated readout, and reset at pixel level. Their intrinsic gain, high immunity to surface and moisture damage, will allow operating these detectors with minimal packaging/passivation requirements and will result in radiation length superior to APS. In Phase I, we designed and fabricated arrays with calorimetric output capable of sub-pixel resolution and sub-microsecond readout rate. The technical effort was dedicated to detector and readout structure development, performance verification, as well as to radiation damage and damage annealing.

  20. Improvement on the light yield of a high-Z inorganic scintillator GSO(Ce)

    CERN Document Server

    Kamae, T; Isobe, N; Kokubun, M; Kubota, A; Osone, S; Takahashi, T; Tsuchida, N; Ishibashi, H

    2002-01-01

    Cerium-doped gadolinium silicic dioxide crystal, GSO(Ce), is a high-Z non-hydroscopic scintillator that gives higher light yield than BGO, and can potentially replace NaI(Tl), CsI(Tl) and BGO in many applications. Its production cost, however, has been substantially higher than any of them, while its energy resolution has been worse than that of NaI(Tl) or CsI(Tl). The merit did not overcome these deficiencies except in limited applications. We developed a low background phoswich counter (the well-type phoswich counter) for the Hard X-ray Detector of the Astro-E project based on GSO scintillator. In the developmental work, we have succeeded in improving the light yield of GSO(Ce) by 40-50%. For energies above 500 keV, a large GSO(Ce) crystal (4.5 cmx4.5phi cm) now gives energy resolution comparable to or better than the best NaI(Tl) when read out with a phototube. With a small GSO(Ce) crystal (5x5x5 mm sup 3) and a photodiode, an energy resolution comparable to or better than the best CsI(Tl) has been obtaine...

  1. Scintillation properties of polycrystalline LaxY1-xO3 ceramic

    Science.gov (United States)

    Sahi, Sunil; Chen, Wei; Kenarangui, Rasool

    2015-03-01

    Scintillators are the material that absorbs the high-energy photons and emits visible photons. Scintillators are commonly used in radiation detector for security, medical imaging, industrial applications and high energy physics research. Two main types of scintillators are inorganic single crystals and organic (plastic or liquid) scintillators. Inorganic single crystals are expensive and difficult to grow in desire shape and size. Also, some efficient inorganic scintillator such as NaI and CsI are not environmental friendly. But on the other hand, organic scintillators have low density and hence poor energy resolution which limits their use in gamma spectroscopy. Polycrystalline ceramic can be a cost effective alternative to expensive inorganic single crystal scintillators. Here we have fabricated La0.2Y1.8O3 ceramic scintillator and studied their luminescence and scintillation properties. Ceramic scintillators were fabricated by vacuum sintering of La0.2Y1.8O3 nanoparticles at temperature below the melting point. La0.2Y1.8O3 ceramic were characterized structurally using XRD and TEM. Photoluminescence and radioluminescence studies were done using UV and X-ray as an excitation source. We have used gamma isotopes with different energy to studies the scintillation properties of La0.2Y1.8O3 scintillator. Preliminary studies of La0.2Y1.8O3 scintillator shows promising result with energy resolution comparable to that of NaI and CsI.

  2. Scintillating liquid xenon calorimeter for precise electron/photon/jet physics at high energy high luminosity hadron colliders

    International Nuclear Information System (INIS)

    Chen, M.; Luckey, D.; Pelly, D.; Shotkin, S.; Sumorok, K.; Wadsworth, B.; Yan, X.J.; You, C.; Zhang, X.; Chen, E.G.; Gaudreau, M.P.J.; Montgomery, D.B.; Sullivan, J.D.; Bolozdynya, A.; Chernyshev, V.; Goritchev, P.; Khovansky, V.; Kouchenkov, A.; Kovalenko, A.; Lebedenko, V.; Vinogradov, V.A.; Epstein, V.; Zeldovich, S.; Krasnokutsky, R.; Shuvalov, R.; Aprile, E.; Mukherjee, R.; Suzuki, M.; Moulsen, M.; Sugimoto, S.; Okada, K.; Fujino, T.; Matsuda, T.; Miyajima, M.; Doke, T.; Kikuchi, J.; Hitachi, A.; Kashiwagi, T.; Nagasawa, Y.; Ichinose, H.; Ishida, N.; Nakasugi, T.; Ito, T.; Masuda, K.; Shibamura, E.; Wallraff, W.; Vivargent, M.; Mutterer, M.; Chen, H.S.; Tang, H.W.; Tung, K.L.; Ding, H.L.; Takahashi, T.

    1990-01-01

    The authors use αs well as e, π, p, d and heavy ion beams to test prototype scintillating liquid xenon detectors, with large UV photodiodes and fast amplifiers submersed directly in liquid xenon. The data show very large photoelectron yields (10 7 /GeV) and high energy resolution (σ(E)/E 1.6 GeV). The α spectra are stable over long term and can be used to calibrate the detectors. Full size liquid xenon detectors have been constructed, to study cosmic μ's and heavy ions. The authors report the progress on the design and construction of the 5 x 5 and 11 x 11 cell liquid xenon detectors which will be tested in high energy beams to determine the e/π ratio. The authors describe the design and the unique properties of the proposed scintillating LXe calorimeter for the SSC

  3. Optimization of the light extraction from heavy inorganic scintillators

    CERN Document Server

    Kronberger, Matthias; Lecoq, P

    2008-01-01

    Inorganic scintillators are widely used in modern medical imaging modalities as converter for the X- and gamma-radiation that is used to obtain information about the interior of the body. Likewise, they are applied in high-energy physics to measure the energy of particles that are produced in particle physics experiments. Their use is motivated by the very good detection efficiency of these materials for hard radiation which allows the construction of relatively compact and finely pixelised systems with a high spatial resolution. One key problem in the development of the next generation of particle detectors and medical imaging systems is the optimisation of the energy resolution of the detectors. This parameter is influenced by the statistical fluctuations of the light output of the scintillators, i.e. by the number of photons that are detected when a particle deposits its energy in the scintillator. The light output of the scintillator depends not only on the absolute number of generated photons but also on...

  4. Depth-of-Interaction Compensation Using a Focused-Cut Scintillator for a Pinhole Gamma Camera

    Science.gov (United States)

    Alhassen, Fares; Kudrolli, Haris; Singh, Bipin; Kim, Sangtaek; Seo, Youngho; Gould, Robert G.; Nagarkar, Vivek V.

    2011-06-01

    Preclinical SPECT offers a powerful means to understand the molecular pathways of drug interactions in animal models by discovering and testing new pharmaceuticals and therapies for potential clinical applications. A combination of high spatial resolution and sensitivity are required in order to map radiotracer uptake within small animals. Pinhole collimators have been investigated, as they offer high resolution by means of image magnification. One of the limitations of pinhole geometries is that increased magnification causes some rays to travel through the detection scintillator at steep angles, introducing parallax errors due to variable depth-of-interaction in scintillator material, especially towards the edges of the detector field of view. These parallax errors ultimately limit the resolution of pinhole preclinical SPECT systems, especially for higher energy isotopes that can easily penetrate through millimeters of scintillator material. A pixellated, focused-cut (FC) scintillator, with its pixels laser-cut so that they are collinear with incoming rays, can potentially compensate for these parallax errors and thus improve the system resolution. We performed the first experimental evaluation of a newly developed focused-cut scintillator. We scanned a Tc-99 m source across the field of view of pinhole gamma camera with a continuous scintillator, a conventional “straight-cut” (SC) pixellated scintillator, and a focused-cut scintillator, each coupled to an electron-multiplying charge coupled device (EMCCD) detector by a fiber-optic taper, and compared the measured full-width half-maximum (FWHM) values. We show that the FWHMs of the focused-cut scintillator projections are comparable to the FWHMs of the thinner SC scintillator, indicating the effectiveness of the focused-cut scintillator in compensating parallax errors.

  5. Depth-of-Interaction Compensation Using a Focused-Cut Scintillator for a Pinhole Gamma Camera.

    Science.gov (United States)

    Alhassen, Fares; Kudrolli, Haris; Singh, Bipin; Kim, Sangtaek; Seo, Youngho; Gould, Robert G; Nagarkar, Vivek V

    2011-06-01

    Preclinical SPECT offers a powerful means to understand the molecular pathways of drug interactions in animal models by discovering and testing new pharmaceuticals and therapies for potential clinical applications. A combination of high spatial resolution and sensitivity are required in order to map radiotracer uptake within small animals. Pinhole collimators have been investigated, as they offer high resolution by means of image magnification. One of the limitations of pinhole geometries is that increased magnification causes some rays to travel through the detection scintillator at steep angles, introducing parallax errors due to variable depth-of-interaction in scintillator material, especially towards the edges of the detector field of view. These parallax errors ultimately limit the resolution of pinhole preclinical SPECT systems, especially for higher energy isotopes that can easily penetrate through millimeters of scintillator material. A pixellated, focused-cut (FC) scintillator, with its pixels laser-cut so that they are collinear with incoming rays, can potentially compensate for these parallax errors and thus improve the system resolution. We performed the first experimental evaluation of a newly developed focused-cut scintillator. We scanned a Tc-99m source across the field of view of pinhole gamma camera with a continuous scintillator, a conventional "straight-cut" (SC) pixellated scintillator, and a focused-cut scintillator, each coupled to an electron-multiplying charge coupled device (EMCCD) detector by a fiber-optic taper, and compared the measured full-width half-maximum (FWHM) values. We show that the FWHMs of the focused-cut scintillator projections are comparable to the FWHMs of the thinner SC scintillator, indicating the effectiveness of the focused-cut scintillator in compensating parallax errors.

  6. Waveshifting fiber readout of lanthanum halide scintillators

    International Nuclear Information System (INIS)

    Case, G.L.; Cherry, M.L.; Stacy, J.G.

    2006-01-01

    Newly developed high-light-yield inorganic scintillators coupled to waveshifting optical fibers provide the capability of efficient X-ray detection and millimeter scale position resolution suitable for high-energy cosmic ray instruments, hard X-ray/gamma ray astronomy telescopes and applications to national security. The CASTER design for NASA's proposed Black Hole Finder Probe mission, in particular, calls for a 6-8 m 2 hard X-ray coded aperture imaging telescope operating in the 20-600 keV energy band, putting significant constraints on cost and readout complexity. The development of new inorganic scintillator materials (e.g., cerium-doped LaBr 3 and LaCl 3 ) provides improved energy resolution and timing performance that is well suited to the requirements for national security and astrophysics applications. LaBr 3 or LaCl 3 detector arrays coupled with waveshifting fiber optic readout represent a significant advance in the performance capabilities of scintillator-based gamma cameras and provide the potential for a feasible approach to affordable, large area, extremely sensitive detectors. We describe some of the applications and present laboratory test results demonstrating the expected scintillator performance

  7. Development of a low-cost-high-sensitivity Compton camera using CsI (Tl) scintillators (γI)

    Energy Technology Data Exchange (ETDEWEB)

    Kagaya, M., E-mail: 13nd401n@vc.ibaraki.ac.jp [College of Science, Ibaraki University, 2-1-1 Bunkyo, Mito City, Ibaraki 310-8512 (Japan); Open-It consortium (Japan); Katagiri, H. [College of Science, Ibaraki University, 2-1-1 Bunkyo, Mito City, Ibaraki 310-8512 (Japan); Open-It consortium (Japan); Enomoto, R. [Institute for Cosmic Ray Research, University of Tokyo, 5-1-5 Kashiwa-no-Ha, Kashiwa City, Chiba 277-8582 (Japan); Open-It consortium (Japan); Hanafusa, R.; Hosokawa, M.; Itoh, Y. [Fuji Electric, 1 Fujimachi, Hino City, Tokyo 191-8502 (Japan); Muraishi, H. [School of Allied Health Science, Kitasato University, 1-15-1 Kitasato, Minami-ku, Sagamihara City, Kanagawa 252-0373 (Japan); Open-It consortium (Japan); Nakayama, K. [College of Science, Ibaraki University, 2-1-1 Bunkyo, Mito City, Ibaraki 310-8512 (Japan); Open-It consortium (Japan); Satoh, K. [Shinsei Corporation, 4-9-1 Nihonbashi-honcho, Chuo-ku, Tokyo 103-0023 (Japan); Takeda, T. [School of Allied Health Science, Kitasato University, 1-15-1 Kitasato, Minami-ku, Sagamihara City, Kanagawa 252-0373 (Japan); Tanaka, M.M.; Uchida, T. [High Energy Accelerator Research Organization, 1-1 Oho, Tsukuba City, Ibaraki 305-0801 (Japan); Open-It consortium (Japan); Watanabe, T. [School of Allied Health Science, Kitasato University, 1-15-1 Kitasato, Minami-ku, Sagamihara City, Kanagawa 252-0373 (Japan); Open-It consortium (Japan); Yanagita, S.; Yoshida, T.; Umehara, K. [College of Science, Ibaraki University, 2-1-1 Bunkyo, Mito City, Ibaraki 310-8512 (Japan); Open-It consortium (Japan)

    2015-12-21

    We have developed a novel low-cost gamma-ray imaging Compton camera γI that has a high detection efficiency. Our motivation for the development of this detector was to measure the arrival directions of gamma rays produced by radioactive nuclides that were released by the Fukushima Daiichi nuclear power plant accident in 2011. The detector comprises two arrays of inorganic scintillation detectors, which act as a scatterer and an absorber. Each array has eight scintillation detectors, each comprising a large CsI (Tl) scintillator cube of side 3.5 cm, which is inexpensive and has a good energy resolution. Energies deposited by the Compton scattered electrons and subsequent photoelectric absorption, measured by each scintillation counter, are used for image reconstruction. The angular resolution was found to be 3.5° after using an image-sharpening technique. With this angular resolution, we can resolve a 1 m{sup 2} radiation hot spot that is located at a distance of 10 m from the detector with a wide field of view of 1 sr. Moreover, the detection efficiency 0.68 cps/MBq at 1 m for 662 keV (7.6 cps/μSv/h) is sufficient for measuring low-level contamination (i.e., less than 1 μSv/h) corresponding to typical values in large areas of eastern Japan. In addition to the laboratory tests, the imaging capability of our detector was verified in various regions with dose rates less than 1 μSv/h (e.g., Fukushima city).

  8. Scintillating plate calorimeter optical design

    International Nuclear Information System (INIS)

    McNeil, R.; Fazely, A.; Gunasingha, R.; Imlay, R.; Lim, J.

    1990-01-01

    A major technical challenge facing the builder of a general purpose detector for the SSC is to achieve an optimum design for the calorimeter. Because of its fast response and good energy resolution, scintillating plate sampling calorimeters should be considered as a possible technology option. The work of the Scintillating Plate Calorimeter Collaboration is focused on compensating plate calorimeters. Based on experimental and simulation studies, it is expected that a sampling calorimeter with alternating layers of high-Z absorber (Pb, W, DU, etc.) and plastic scintillator can be made compensating (e/h = 1.00) by suitable choice of the ratio of absorber/scintillator thickness. Two conceptual designs have been pursued by this subsystem collaboration. One is based on lead as the absorber, with read/out of the scintillator plates via wavelength shifter fibers. The other design is based on depleted uranium as the absorber with wavelength shifter (WLS) plate readout. Progress on designs for the optical readout of a compensating scintillator plate calorimeter are presented. These designs include readout of the scintillator plates via wavelength shifter plates or fiber readout. Results from radiation damage studies of the optical components are presented

  9. Large area avalanche photodiodes in scintillation and X-rays detection

    CERN Document Server

    Moszynski, M; Kapusta, M; Balcerzyk, M

    2002-01-01

    The presented paper summarizes our earlier studies on application of beveled-edge Large Area Avalanche Photodiodes (LAAPDs) in gamma-rays scintillation detection. LAAPDs, due to their high quantum efficiency and low excess noise factor allow for better statistical accuracy of the signal as compared to photomultipliers. The device dark noise contribution significantly affects energy resolution only for gamma-rays with energy below 50 keV. Notably better or comparable energy resolutions to those observed with a XP2020Q photomultiplier were obtained with the LAAPDs for a number of different scintillators. Particularly, the recorded energy resolutions of 4.3+-0.2% and 4.8+-0.14% measured with YAP and CsI(Tl) crystals, respectively, for the 662 keV gamma-peak from a sup 1 sup 3 sup 7 Cs source belong to the best observed ever with these scintillation detectors. Results of the study of timing with fast scintillators coupled to the LAAPD showed subnanosecond time resolution of 570+-30 ps for sup 6 sup 0 Co gamma-ray...

  10. High resolution phoswich gamma-ray imager utilizing monolithic MPPC arrays with submillimeter pixelized crystals

    International Nuclear Information System (INIS)

    Kato, T; Kataoka, J; Nakamori, T; Kishimoto, A; Yamamoto, S; Sato, K; Ishikawa, Y; Yamamura, K; Kawabata, N; Ikeda, H; Kamada, K

    2013-01-01

    We report the development of a high spatial resolution tweezers-type coincidence gamma-ray camera for medical imaging. This application consists of large-area monolithic Multi-Pixel Photon Counters (MPPCs) and submillimeter pixelized scintillator matrices. The MPPC array has 4 × 4 channels with a three-side buttable, very compact package. For typical operational gain of 7.5 × 10 5 at + 20 °C, gain fluctuation over the entire MPPC device is only ± 5.6%, and dark count rates (as measured at the 1 p.e. level) amount to ≤ 400 kcps per channel. We selected Ce-doped (Lu,Y) 2 (SiO 4 )O (Ce:LYSO) and a brand-new scintillator, Ce-doped Gd 3 Al 2 Ga 3 O 12 (Ce:GAGG) due to their high light yield and density. To improve the spatial resolution, these scintillators were fabricated into 15 × 15 matrices of 0.5 × 0.5 mm 2 pixels. The Ce:LYSO and Ce:GAGG scintillator matrices were assembled into phosphor sandwich (phoswich) detectors, and then coupled to the MPPC array along with an acrylic light guide measuring 1 mm thick, and with summing operational amplifiers that compile the signals into four position-encoded analog outputs being used for signal readout. Spatial resolution of 1.1 mm was achieved with the coincidence imaging system using a 22 Na point source. These results suggest that the gamma-ray imagers offer excellent potential for applications in high spatial medical imaging.

  11. Photocathode non-uniformity contribution to the energy resolution of scintillators

    International Nuclear Information System (INIS)

    Mottaghian, M.; Koohi-Fayegh, R.; Ghal-Eh, N.; Etaati, G. R.

    2010-01-01

    This paper introduces the basics of the light transport simulation in scintillators and the wavelength-dependencies in the process. The non-uniformity measurement of the photocathode surface is undertaken, showing that for the photocathode used in this study the quantum efficiency falls to about 4% of its maximum value, especially in areas far from the centre. The wavelength-and position-dependent quantum efficiency is implemented in the Monte Carlo light transport code, showing that, the contribution of the photocathode non-uniformity to the energy resolution is estimated to be around 18%, when all position-and wavelength-dependencies are included. (authors)

  12. Large area avalanche photodiodes in scintillation and X-rays detection

    International Nuclear Information System (INIS)

    Moszynski, M.; Szawlowski, M.; Kapusta, M.; Balcerzyk, M.

    2002-01-01

    The presented paper summarizes our earlier studies on application of beveled-edge Large Area Avalanche Photodiodes (LAAPDs) in γ-rays scintillation detection. LAAPDs, due to their high quantum efficiency and low excess noise factor allow for better statistical accuracy of the signal as compared to photomultipliers. The device dark noise contribution significantly affects energy resolution only for γ-rays with energy below 50 keV. Notably better or comparable energy resolutions to those observed with a XP2020Q photomultiplier were obtained with the LAAPDs for a number of different scintillators. Particularly, the recorded energy resolutions of 4.3±0.2% and 4.8±0.14% measured with YAP and CsI(Tl) crystals, respectively, for the 662 keV γ-peak from a 137 Cs source belong to the best observed ever with these scintillation detectors. Results of the study of timing with fast scintillators coupled to the LAAPD showed subnanosecond time resolution of 570±30 ps for 60 Co γ-rays detected in LSO crystal. The response of LAAPD to X-rays and factors limiting energy resolution have been discussed too

  13. Survey meter using novel inorganic scintillators

    International Nuclear Information System (INIS)

    Yoshikawa, Akira; Fukuda, Kentaro; Kawaguchi, Noriaki; Kamada, Kei; Fujimoto, Yutaka; Yokota, Yuui; Kurosawa, Shunsuke; Yanagida, Takayuki

    2012-01-01

    Single crystal scintillator materials are widely used for detection of high-energy photons and particles. There is continuous demand for new scintillator materials with higher performance because of increasing number of medical, industrial, security and other applications. This article presents the recent development of three novel inorganic scintillators; Pr-doped Lu 3 Al 5 O 12 (Pr:LuAG), Ce doped Gd 3 (Al, Ga) 5 O 12 (Ce:GAGG) and Ce or Eu-doped 6 LiCaAlF 6 (Ce:LiCAF, Eu:LiCAF). Pr:LuAG shows very interesting scintillation properties including very fast decay time, high light yield and excellent energy resolution. Taking the advantage of these properties, positron emission mammography (PEM) equipped with Pr:LuAG were developed. Ce:GAGG shows very high light yield, which is much higher than that of Ce:LYSO. Survey meter using Ce:GAGG is developed using this scintillator. Ce:LiCAF and Eu:LiCAF were developed for neutron detection. The advantage and disadvantage are discussed comparing with halide scintillators. Eu-doped LiCAF indicated five times higher light yield than that of existing Li-glass. It is expected to be used as the alternative of 3 He. (author)

  14. Time-of-flight resolution of scintillating counters with Burle 85001 microchannel plate photomultipliers in comparison with Hamamatsu R2083

    Energy Technology Data Exchange (ETDEWEB)

    Baturin, V. [Department of Physics, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Burkert, V. [Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606 (United States); Kim, W. [Department of Physics, Kyungpook National University, Daegu 702-701 (Korea, Republic of)]. E-mail: wooyoung@jlab.org; Majewsky, S. [Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606 (United States); Park, K. [Department of Physics, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Popov, V. [Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606 (United States); Smith, E.S. [Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606 (United States); Son, D. [Department of Physics, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Stepanyan, S.S. [Department of Physics, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Zorn, C. [Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606 (United States)

    2006-06-15

    Improvements in the time resolution of the CEBAF Large Acceptance Spectrometer (CLAS) below {approx}50ps will be required for experiments using the planned upgraded accelerator facility at Jefferson Lab. The improved time resolution will allow particle identification using time-of-flight techniques to be used effectively up to the proposed operating energy of 12GeV. The challenge of achieving this time resolution over a relatively large area is compounded because the photomultipliers (PM) in the CLAS 'time-zero' scintillating counters must operate in very high magnetic fields. Therefore, we have studied the resolution of 'time-zero' prototypes with microchannel plate PMs 85001-501 from Burle. For reference and comparison, measurements were also made using the standard PMs R2083 from Hamamatsu using two timing methods. The cosmic ray method, which utilizes three identical scintillating counters (Bicron BC-408, 2x3x50cm{sup 3}) with PMs at the ends, yields {sigma}{sub R2083}=59.1+/-0.7ps. The location method of particles from a radiative source with known coordinates has been used to compare timing resolutions of R2083 and 85001-501. This method yields {sigma}{sub R2083}=59.5+/-0.7ps and it also provides an estimate of the number of primary photoelectrons. For the microchannel plate PM from Burle the method yields {sigma}{sub 85001}=130+/-4ps due to lower number of primary photoelectrons.

  15. A novel high resolution, high sensitivity SPECT detector for molecular imaging of cardiovascular diseases

    Science.gov (United States)

    Cusanno, F.; Argentieri, A.; Baiocchi, M.; Colilli, S.; Cisbani, E.; De Vincentis, G.; Fratoni, R.; Garibaldi, F.; Giuliani, F.; Gricia, M.; Lucentini, M.; Magliozzi, M. L.; Majewski, S.; Marano, G.; Musico, P.; Musumeci, M.; Santavenere, F.; Torrioli, S.; Tsui, B. M. W.; Vitelli, L.; Wang, Y.

    2010-05-01

    Cardiovascular diseases are the most common cause of death in western countries. Understanding the rupture of vulnerable atherosclerotic plaques and monitoring the effect of innovative therapies of heart failure is of fundamental importance. A flexible, high resolution, high sensitivity detector system for molecular imaging with radionuclides on small animal models has been designed for this aim. A prototype has been built using tungsten pinhole and LaBr3(Ce) scintillator coupled to Hamamatsu Flat Panel PMTs. Compact individual-channel readout has been designed, built and tested. Measurements with phantoms as well as pilot studies on mice have been performed, the results show that the myocardial perfusion in mice can be determined with sufficient precision. The detector will be improved replacing the Hamamatsu Flat Panel with Silicon Photomultipliers (SiPMs) to allow integration of the system with MRI scanners. Application of LaBr3(Ce) scintillator coupled to photosensor with high photon detection efficiency and excellent energy resolution will allow dual-label imaging to monitor simultaneously the cardiac perfusion and the molecular targets under investigation during the heart therapy.

  16. Real-time volumetric scintillation dosimetry

    International Nuclear Information System (INIS)

    Beddar, S

    2015-01-01

    The goal of this brief review is to review the current status of real-time 3D scintillation dosimetry and what has been done so far in this area. The basic concept is to use a large volume of a scintillator material (liquid or solid) to measure or image the dose distributions from external radiation therapy (RT) beams in three dimensions. In this configuration, the scintillator material fulfills the dual role of being the detector and the phantom material in which the measurements are being performed. In this case, dose perturbations caused by the introduction of a detector within a phantom will not be at issue. All the detector configurations that have been conceived to date used a Charge-Coupled Device (CCD) camera to measure the light produced within the scintillator. In order to accurately measure the scintillation light, one must correct for various optical artefacts that arise as the light propagates from the scintillating centers through the optical chain to the CCD chip. Quenching, defined in its simplest form as a nonlinear response to high-linear energy transfer (LET) charged particles, is one of the disadvantages when such systems are used to measure the absorbed dose from high-LET particles such protons. However, correction methods that restore the linear dose response through the whole proton range have been proven to be effective for both liquid and plastic scintillators. Volumetric scintillation dosimetry has the potential to provide fast, high-resolution and accurate 3D imaging of RT dose distributions. Further research is warranted to optimize the necessary image reconstruction methods and optical corrections needed to achieve its full potential

  17. High spatial resolution gamma imaging detector based on a 5 inch diameter R3292 Hamamatsu PSPMT

    International Nuclear Information System (INIS)

    Wojcik, R.; Majewski, S.; Kross, B.; Weisenberger, A.G.; Steinbach, D.

    1998-01-01

    High resolution imaging gamma-ray detectors were developed using Hamamatsu's 5 inch diameter R3292 position sensitive PMT (PSPMT) and a variety of crystal scintillator arrays. Special readout techniques were used to maximize the active imaging area while reducing the number of readout channels. Spatial resolutions approaching 1 mm were obtained in a broad energy range from 20 to 511 keV. Results are also presented of coupling the scintillator arrays to the PMT via imaging light guides consisting of acrylic optical fibers

  18. High-Resolution Imaging System (HiRIS) based on H9500 PSPMT

    International Nuclear Information System (INIS)

    Trotta, C.; Massari, R.; Trinci, G.; Palermo, N.; Boccalini, S.; Scopinaro, F.; Soluri, A.

    2008-01-01

    The H8500 PhotoMultiplier Tube (PMT) from Hamamatsu has been used in the last years to assemble several scintigraphic devices in order to achieve high-resolution gamma cameras. If the detector is coupled to discrete scintillator with millimetric pixel size, the resulting charge distribution that emerges is not properly sampled by its anodes (6x6 mm 2 ). The new position sensitive PMT H9500, with its 3x3 mm 2 anodes, allows a better charge distribution sampling, improving both spatial resolution and linearity of the system. In this paper, we investigate the imaging performances of the H9500 PMT coupled with a CsI(Tl) array having 1 mm pixel size and compare the results with the same scintillator coupled with H8500 PMT. A portable imaging system named HiRIS (High-Resolution Imaging System) was then realized using a miniaturized readout electronic. Thanks to its lightness, it can be easily used in Medical Imaging. We used HiRIS, together with a rotating system, to carry out a tomographic reconstruction of the biodistribution of a radiopharmaceutical in rats

  19. Influence of inhomogeneities in scintillating fibre electromagnetic calorimeter on its energy resolution

    International Nuclear Information System (INIS)

    Stavina, P.; Tokar, S.; Budagov, Yu.A.; Chirikov-Zorin, I.; Pantea, D.

    1998-01-01

    The specific aspects related to the discrete structure of the scintillating fibre electromagnetic calorimeter are investigated by means of Monte-Carlo simulation. It is shown that the structure inhomogeneity leads to an additional contribution to the systematic term in the energy resolution parametrization formula which weakly depends on energy and to the distortion of the Gaussian form of response distribution. The investigation was carried out for small tilt angles and for the absorber-to-fibre ratio 4:1

  20. New scintillating crystals for PET scanners

    CERN Document Server

    Lecoq, P

    2002-01-01

    Systematic R&D on basic mechanism in inorganic scintillators, initiated by the Crystal Clear Collaboration at CERN 10 years ago, has contributed not to a small amount, to the development of new materials for a new generation of medical imaging devices with increased resolution and sensitivity. The first important requirement for a scintillator to be used in medical imaging devices is the stopping power for the given energy range of X and gamma rays to be considered, and more precisely the conversion efficiency. A high light yield is also mandatory to improve the energy resolution, which is essentially limited by the photostatistics and the electronic noise at these energies. A short scintillation decay time allows to reduce the dead time and therefore to increase the limiting counting rate. When all these requirements are fulfilled the sensitivity and image contrast are increased for a given patient dose, or the dose can be reduced. Examples of new materials under development by the Crystal Clear Collabor...

  1. Optimization of light collection from crystal scintillators for cryogenic experiments

    International Nuclear Information System (INIS)

    Mokina, V.M.; Danevich, F.A.; Kobychev, V.V.; Kraus, H.; Mikhailik, V.B.; Nagornaya, L.L.

    2012-01-01

    Cryogenic scintillation bolometers are a promising technique to search for dark matter and neutrinoless double decay. Improvement of light collection and energy resolution are important requirements in such experiments. Energy resolutions and relative pulse amplitudes of scintillation detectors using ZnWO 4 scintillation crystals of different shapes (cylinder 20x20 mm and hexagonal prism with diagonal 20 mm and height 20 mm), reflector materials and shapes, optical contact and surface properties (polished and diffused) were measured. The crystal scintillator of hexagonal shape shows the better energy resolution and pulse amplitude. The best energy resolution (FWHM = 9.3 % for 662 keV γ quanta of 137 Cs) was obtained with a hexagonal scintillator with all surfaces diffuse, in optical contact with a PMT and surrounded by a reflector (3M) of size 26x25 mm. In the geometry w ithout optical contact r epresenting the conditions of light collection for a cryogenic scintillating bolometer the best energy resolution and relative pulse amplitude was obtained for a hexagonal shape scintillator with diffuse side and polished face surfaces, surrounded by a reflector with a gap between the scintillator and the reflector

  2. Thallium bromide photodetectors for scintillation detection

    CERN Document Server

    Hitomi, K; Shoji, T; Hiratate, Y; Ishibashi, H; Ishii, M

    2000-01-01

    A wide bandgap compound semiconductor, TlBr, has been investigated as a blue sensitive photodetector material for scintillation detection. The TlBr photodetectors have been fabricated from the TlBr crystals grown by the TMZ method using materials purified by many pass zone refining. The performance of the photodetectors has been evaluated by measuring their leakage current, quantum efficiency, spatial uniformity, direct X-ray detection and scintillation detection characteristics. The photodetectors have shown high quantum efficiency for the blue wavelength region and high spatial uniformity for their optical response. In addition, good direct X-ray detection characteristics with an energy resolution of 4.5 keV FWHM for 22 keV X-rays from a sup 1 sup 0 sup 9 Cd radioactive source have been obtained. Detection of blue scintillation from GSO and LSO scintillators irradiated with a sup 2 sup 2 Na radioactive source has been done successfully by using the photodetectors at room temperature. A clear full-energy pea...

  3. Collimator trans-axial tomographic scintillation camera

    International Nuclear Information System (INIS)

    Jaszczak, R.J.

    1977-01-01

    A collimator is provided for a scintillation camera system in which a detector precesses in an orbit about a patient. The collimator is designed to have high resolution and lower sensitivity with respect to radiation traveling in paths laying wholly within planes perpendicular to the cranial-caudal axis of the patient. The collimator has high sensitivity and lower resolution to radiation traveling in other planes. Variances in resolution and sensitivity are achieved by altering the length, spacing or thickness of the septa of the collimator

  4. X-ray Tomography using Thin Scintillator Films

    CERN Document Server

    Kozyrev, E A; Lemzyakov, A G; Petrozhitskiy, A V; Popov, A S

    2017-01-01

    2-14 μm thin CsI:Tl scintillation screens with high spatial resolution were prepared by the thermal deposition method for low energy X-ray imaging applications. The spatial resolution was measured as a function of the film thickness. It was proposed that the spatial resolution of the prepared conversion screens can be significantly improved by an additional deposition of a carbon layer.

  5. Taheri-Saramad x-ray detector (TSXD): a novel high spatial resolution x-ray imager based on ZnO nano scintillator wires in polycarbonate membrane.

    Science.gov (United States)

    Taheri, A; Saramad, S; Ghalenoei, S; Setayeshi, S

    2014-01-01

    A novel x-ray imager based on ZnO nanowires is designed and fabricated. The proposed architecture is based on scintillation properties of ZnO nanostructures in a polycarbonate track-etched membrane. Because of higher refractive index of ZnO nanowire compared to the membrane, the nanowire acts as an optical fiber that prevents the generated optical photons to spread inside the detector. This effect improves the spatial resolution of the imager. The detection quantum efficiency and spatial resolution of the fabricated imager are 11% and <6.8 μm, respectively.

  6. Taheri-Saramad x-ray detector (TSXD): A novel high spatial resolution x-ray imager based on ZnO nano scintillator wires in polycarbonate membrane

    Energy Technology Data Exchange (ETDEWEB)

    Taheri, A., E-mail: at1361@aut.ac.ir; Saramad, S.; Ghalenoei, S.; Setayeshi, S. [Department of Energy Engineering and Physics, Amirkabir University of Technology, Tehran 15875-4413 (Iran, Islamic Republic of)

    2014-01-15

    A novel x-ray imager based on ZnO nanowires is designed and fabricated. The proposed architecture is based on scintillation properties of ZnO nanostructures in a polycarbonate track-etched membrane. Because of higher refractive index of ZnO nanowire compared to the membrane, the nanowire acts as an optical fiber that prevents the generated optical photons to spread inside the detector. This effect improves the spatial resolution of the imager. The detection quantum efficiency and spatial resolution of the fabricated imager are 11% and <6.8 μm, respectively.

  7. CeBr3 as a room-temperature, high-resolution gamma-ray detector

    International Nuclear Information System (INIS)

    Guss, Paul; Reed, Michael; Yuan Ding; Reed, Alexis; Mukhopadhyay, Sanjoy

    2009-01-01

    Cerium bromide (CeBr 3 ) has become a material of interest in the race for high-resolution gamma-ray spectroscopy at room temperature. This investigation quantified the potential of CeBr 3 as a room-temperature, high-resolution gamma-ray detector. The performance of CeBr 3 crystals was compared to other scintillation crystals of similar dimensions and detection environments. Comparison of self-activity of CeBr 3 to cerium-doped lanthanum tribromide (LaBr 3 :Ce) was performed. Energy resolution and relative intrinsic efficiency were measured and are presented.

  8. Feasibility of a novel design of high resolution parallax-free Compton enhanced PET scanner dedicated to brain research

    CERN Document Server

    Braem, André; Chesi, Enrico Guido; Correia, J G; Garibaldi, F; Joram, C; Mathot, S; Nappi, E; Ribeiro da Silva, M; Schoenahl, F; Séguinot, Jacques; Weilhammer, P; Zaidi, H

    2004-01-01

    A novel concept for a positron emission tomography (PET) camera module is proposed, which provides full 3D reconstruction with high resolution over the total detector volume, free of parallax errors. The key components are a matrix of long scintillator crystals and hybrid photon detectors (HPDs) with matched segmentation and integrated readout electronics. The HPDs read out the two ends of the scintillator package. Both excellent spatial (x, y, z) and energy resolution are obtained. The concept allows enhancing the detection efficiency by reconstructing a significant fraction of events which underwent Compton scattering in the crystals. The proof of concept will first be demonstrated with yttrium orthoaluminate perovskite (YAP):Ce crystals, but the final design will rely on other scintillators more adequate for PET applications (e.g. LSO:Ce or LaBr /sub 3/:Ce). A promising application of the proposed camera module, which is currently under development, is a high resolution 3D brain PET camera with an axial fi...

  9. Time resolution measurements with an improved discriminator and conical scintillators

    International Nuclear Information System (INIS)

    McGervey, J.D.; Vogel, J.; Sen, P.; Knox, C.

    1977-01-01

    A new constant fraction discriminator with improved stability and walk characteristics is described. The discriminator was used with RCA C31024 photomultiplier tubes to test scintillators of conical and cylindrical shapes. Conical scintillators of 2.54 cm base diameter, 1.0 cm top diameter, and 2.54 cm height gave a fwhm of 155 ps for 60 Co gamma rays; larger conical scintillators gave an improvement of 10-15% in fwhm over cylindrical scintillators of equal volume. (Auth.)

  10. Toward the Probabilistic Forecasting of High-latitude GPS Phase Scintillation

    Science.gov (United States)

    Prikryl, P.; Jayachandran, P.T.; Mushini, S. C.; Richardson, I. G.

    2012-01-01

    The phase scintillation index was obtained from L1 GPS data collected with the Canadian High Arctic Ionospheric Network (CHAIN) during years of extended solar minimum 2008-2010. Phase scintillation occurs predominantly on the dayside in the cusp and in the nightside auroral oval. We set forth a probabilistic forecast method of phase scintillation in the cusp based on the arrival time of either solar wind corotating interaction regions (CIRs) or interplanetary coronal mass ejections (ICMEs). CIRs on the leading edge of high-speed streams (HSS) from coronal holes are known to cause recurrent geomagnetic and ionospheric disturbances that can be forecast one or several solar rotations in advance. Superposed epoch analysis of phase scintillation occurrence showed a sharp increase in scintillation occurrence just after the arrival of high-speed solar wind and a peak associated with weak to moderate CMEs during the solar minimum. Cumulative probability distribution functions for the phase scintillation occurrence in the cusp are obtained from statistical data for days before and after CIR and ICME arrivals. The probability curves are also specified for low and high (below and above median) values of various solar wind plasma parameters. The initial results are used to demonstrate a forecasting technique on two example periods of CIRs and ICMEs.

  11. Simulation Study of Using High-Z EMA to Suppress Recoil Protons Crosstalk in Scintillating Fiber Array for 14.1 MeV Neutron Imaging

    Science.gov (United States)

    Jia, Qinggang; Hu, Huasi; Zhang, Fengna; Zhang, Tiankui; Lv, Wei; Zhan, Yuanpin; Liu, Zhihua

    2013-12-01

    This paper studies the effect of a high-Z extra mural absorber (EMA) to improve the spatial resolution of a plastic (polystyrene) scintillating fiber array for 14.1 MeV fusion neutron imaging. Crosstalk induced by recoil protons was studied, and platinum (Pt) was selected as EMA material, because of its excellent ability to suppress the recoil protons penetrating the fibers. Three common fiber arrays (cylindrical scintillating fibers in square and hexagonal packing arrangements and square scintillating fibers) were simulated using the Monte Carlo method for evaluating the effect of Pt-EMA in improving spatial resolution. It is found that the resolution of the 100 μm square fiber array can be improved from 1.7 to 3.4 lp/mm by using 10- μm-thick Pt-EMA; comparatively, using an array with thinner square fibers (50 μm) only obtains a resolution of 2.1 lp/mm. The packing fraction decreases with the increase of EMA thickness. Our results recommend the use of 10 μm Pt-EMA for the square and the cylindrical (hexagonal packing) scintillating fiber arrays with fibers of 50-200 μm in the cross-sectional dimension. Besides, the dead-zone material should be replaced by high-Z material for the hexagonal packing cylindrical fiber array with fibers of 50-200 μm in diameter. Tungsten (W) and gold (Au) are also used as EMA in the three fiber arrays as a comparison. The simulation results show that W can be used at a lower cost, and Au does not have any advantages in cost and resolution improvement.

  12. Novel scintillators and silicon photomultipliers for nuclear physics and applications

    International Nuclear Information System (INIS)

    Jenkins, David

    2015-01-01

    Until comparatively recently, scintillator detectors were seen as an old-fashioned tool of nuclear physics with more attention being given to areas such as gamma-ray tracking using high-purity germanium detectors. Next-generation scintillator detectors, such as lanthanum bromide, which were developed for the demands of space science and gamma- ray telescopes, are found to have strong applicability to low energy nuclear physics. Their excellent timing resolution makes them very suitable for fast timing measurements and their much improved energy resolution compared to conventional scintillators promises to open up new avenues in nuclear physics research which were presently hard to access. Such 'medium-resolution' spectroscopy has broad interest across several areas of contemporary interest such as the study of nuclear giant resonances. In addition to the connections to space science, it is striking that the demands of contemporary medical imaging have strong overlap with those of experimental nuclear physics. An example is the interest in PET-MRI combined imaging which requires putting scintillator detectors in a high magnetic field environment. This has led to strong advances in the area of silicon photomultipliers, a solid-state replacement for photomultiplier tubes, which are insensitive to magnetic fields. Broad application to nuclear physics of this technology may be foreseen. (paper)

  13. 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

  14. Influence of inhomogeneities in scintillating fibre electromagnetic calorimeter on its energy resolution

    Energy Technology Data Exchange (ETDEWEB)

    Stavina, P; Tokar, S [Department of Nuclear Physics, Comenius University, Bratislava (Slovak Republic); Budagov, Yu A [Joint Institute for Nuclear Research, Dubna (Russian Federation); Chirikov-Zorin, I; Pantea, D [Institute of Atomic Physics, Bucharest (Romania)

    1998-12-01

    The specific aspects related to the discrete structure of the scintillating fibre electromagnetic calorimeter are investigated by means of Monte-Carlo simulation. It is shown that the structure inhomogeneity leads to an additional contribution to the systematic term in the energy resolution parametrization formula which weakly depends on energy and to the distortion of the Gaussian form of response distribution. The investigation was carried out for small tilt angles and for the absorber-to-fibre ratio 4:1 10 refs., 7 refs., 2 tabs.

  15. High-symmetry organic scintillator systems

    Science.gov (United States)

    Feng, Patrick L.

    2017-07-18

    An ionizing radiation detector or scintillator system includes a scintillating material comprising an organic crystalline compound selected to generate photons in response to the passage of ionizing radiation. The organic compound has a crystalline symmetry of higher order than monoclinic, for example an orthorhombic, trigonal, tetragonal, hexagonal, or cubic symmetry. A photodetector is optically coupled to the scintillating material, and configured to generate electronic signals having pulse shapes based on the photons generated in the scintillating material. A discriminator is coupled to the photon detector, and configured to discriminate between neutrons and gamma rays in the ionizing radiation based on the pulse shapes of the output signals.

  16. High-symmetry organic scintillator systems

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Patrick L.

    2018-03-13

    An ionizing radiation detector or scintillator system includes a scintillating material comprising an organic crystalline compound selected to generate photons in response to the passage of ionizing radiation. The organic compound has a crystalline symmetry of higher order than monoclinic, for example an orthorhombic, trigonal, tetragonal, hexagonal, or cubic symmetry. A photodetector is optically coupled to the scintillating material, and configured to generate electronic signals having pulse shapes based on the photons generated in the scintillating material. A discriminator is coupled to the photon detector, and configured to discriminate between neutrons and gamma rays in the ionizing radiation based on the pulse shapes of the output signals.

  17. High-symmetry organic scintillator systems

    Science.gov (United States)

    Feng, Patrick L.

    2018-02-06

    An ionizing radiation detector or scintillator system includes a scintillating material comprising an organic crystalline compound selected to generate photons in response to the passage of ionizing radiation. The organic compound has a crystalline symmetry of higher order than monoclinic, for example an orthorhombic, trigonal, tetragonal, hexagonal, or cubic symmetry. A photodetector is optically coupled to the scintillating material, and configured to generate electronic signals having pulse shapes based on the photons generated in the scintillating material. A discriminator is coupled to the photon detector, and configured to discriminate between neutrons and gamma rays in the ionizing radiation based on the pulse shapes of the output signals.

  18. Evaluations of the new LiF-scintillator and optional brightness enhancement films for neutron imaging

    Energy Technology Data Exchange (ETDEWEB)

    Iikura, H., E-mail: Iikura.hiroshi@jaea.go.jp [Japan Atomic Energy Agency, 2-4 Shirakata-shirane, Tokai-mura, Naka-gun, Ibaraki (Japan); Tsutsui, N. [Chichibu Fuji Co., Ltd., Ogano, Chichibu, Saitama 368-0193 (Japan); Nakamura, T.; Katagiri, M.; Kureta, M. [Japan Atomic Energy Agency, 2-4 Shirakata-shirane, Tokai-mura, Naka-gun, Ibaraki (Japan); Kubo, J. [Nissan Motor Co., Ltd., Atsugi, Kanagawa 243-0126 (Japan); Matsubayashi, M. [Japan Atomic Energy Agency, 2-4 Shirakata-shirane, Tokai-mura, Naka-gun, Ibaraki (Japan)

    2011-09-21

    Japan Atomic Energy Agency has developed the neutron scintillator jointly with Chichibu Fuji Co., Ltd. In this study, we evaluated the new ZnS(Ag):Al/{sup 6}Li scintillator developed for neutron imaging. It was confirmed that the brightness increased by about double while maintaining equal performance for the spatial resolution as compared with a conventional scintillator. High frame-rate imaging using a high-speed video camera system and this new scintillator made it possible to image beyond 10 000 frames per second while still having enough brightness. This technique allowed us to obtain a high-frame-rate visualization of oil flow in a running car engine. Furthermore, we devised a technique to increase the light intensity of reception for a camera by adding brightness enhancement films on the output surface of the scintillator. It was confirmed that the spatial resolution degraded more than double, but the brightness increased by about three times.

  19. Scintillation trigger system of the liquid argon neutrino detector

    International Nuclear Information System (INIS)

    Belikov, S.V.; Gurzhiev, S.N.; Gutnikov, Yu.E.; Denisov, A.G.; Kochetkov, V.I.; Matveev, M.Yu.; Mel'nikov, E.A.; Usachev, A.P.

    1994-01-01

    This paper presents the organization of the Scintillation Trigger System (STS) for the Liquid Argon Neutrino Detector of the Tagged Neutrino Facility. STS is aimed at the effective registration of the needed neutrino interaction type and production of a fast trigger signal with high time resolution. The fast analysis system of analog signal from the trigger scintillation planes for rejection of the trigger signals from background processes is described. Real scintillation trigger planes characteristics obtained on the basis of the presented data acquisition system are shown. 10 refs., 12 figs., 3 tabs

  20. Status of timing with plastic scintillation detectors

    International Nuclear Information System (INIS)

    Moszynski, M.; Bengtson, B.

    1979-01-01

    Timing properties of scintillators and photomultipliers as well as theoretical and experimental studies of time resolution of scintillation counters are reviewed. Predictions of the theory of the scintillation pulse generation processes are compared with the data on the light pulse shape from small samples, in which the light pulse shape depends only on the composition of the scintillator. For larger samples the influence of the light collection process and the self-absorption process on the light pulse shape are discussed. The data on rise times, fwhm's, decay times and light yield of several commercial scintillators used in timing are collected. The next part of the paper deals with the properties of photomultipliers. The sources of time uncertainties in photomultipliers as a spread of the initial velocity of photoelectrons, emission of photoelectrons under different angles and from different points at the photocathode, the time spread and the gain dispersion introduced by electron photomultiplier are reviewed. The experimental data on the time jitter, single electron response and photoelectron yield of some fast photomultipliers are collected. As the time resolution of the timing systems with scintillation counters depends also on time pick-off units, a short presentation of the timing methods is given. The discussion of timing theories is followed by a review of experimental studies of the time resolution of scintillation counters. The paper is ended by an analysis of prospects on further progress of the subnanosecond timing with scintillation counters. (Auth.)

  1. Plastic scintillators with high loading of one or more metal carboxylates

    Science.gov (United States)

    Cherepy, Nerine; Sanner, Robert Dean

    2016-01-12

    In one embodiment, a material includes at least one metal compound incorporated into a polymeric matrix, where the metal compound includes a metal and one or more carboxylate ligands, where at least one of the one or more carboxylate ligands includes a tertiary butyl group, and where the material is optically transparent. In another embodiment, a method includes: processing pulse traces corresponding to light pulses from a scintillator material; and outputting a result of the processing, where the scintillator material comprises at least one metal compound incorporated into a polymeric matrix, the at least one metal compound including a metal and one or more carboxylate ligands, where at least one of the one or more carboxylate ligands has a tertiary butyl group, and where the scintillator material is optically transparent and has an energy resolution at 662 keV of less than about 20%.

  2. Characterisation of a LSO scintillation crystal for space applications

    Energy Technology Data Exchange (ETDEWEB)

    Elftmann, Robert; Grunau, Jan; Kulkarni, Shrinivasrao; Martin, Cesar; Wimmer-Schweingruber, Robert F. [IEAP, Christian-Albrechts-Universitaet Kiel (Germany)

    2013-07-01

    Inorganic scintillation crystals coupled with semiconductor detectors are often used in space applications as gamma ray detectors or high energy particle calorimeters. Currently BGO (Bi{sub 4}Ge{sub 3}O{sub 12}) is widely used for this purpose because of its high stopping power, the non hygroscopy and its ruggedness, which is favorable in space applications. Cerium doped LSO (Lu{sub 2}SiO{sub 5}) offers the same benefits with higher light output capabilites and a shorter decay time. In this work a cerium doped LSO scintillation crystal coupled with a photo diode is investigated. The light yield and resolution studies for two different radioactive sources, {sup 207}Bi and {sup 60}Co, are presented. To increase the light collection and consequently the energy resolution, scintillation crystals are wrapped in highly reflective material. The increase in light collection depending on the amount of layers for the LSO crystal along with investigations of quenching effects with alpha particles and the background spectrum, which arises from radioactive cerium isotopes, are also included in this work.

  3. Design and image-quality performance of high resolution CMOS-based X-ray imaging detectors for digital mammography

    Science.gov (United States)

    Cha, B. K.; Kim, J. Y.; Kim, Y. J.; Yun, S.; Cho, G.; Kim, H. K.; Seo, C.-W.; Jeon, S.; Huh, Y.

    2012-04-01

    In digital X-ray imaging systems, X-ray imaging detectors based on scintillating screens with electronic devices such as charge-coupled devices (CCDs), thin-film transistors (TFT), complementary metal oxide semiconductor (CMOS) flat panel imagers have been introduced for general radiography, dental, mammography and non-destructive testing (NDT) applications. Recently, a large-area CMOS active-pixel sensor (APS) in combination with scintillation films has been widely used in a variety of digital X-ray imaging applications. We employed a scintillator-based CMOS APS image sensor for high-resolution mammography. In this work, both powder-type Gd2O2S:Tb and a columnar structured CsI:Tl scintillation screens with various thicknesses were fabricated and used as materials to convert X-ray into visible light. These scintillating screens were directly coupled to a CMOS flat panel imager with a 25 × 50 mm2 active area and a 48 μm pixel pitch for high spatial resolution acquisition. We used a W/Al mammographic X-ray source with a 30 kVp energy condition. The imaging characterization of the X-ray detector was measured and analyzed in terms of linearity in incident X-ray dose, modulation transfer function (MTF), noise-power spectrum (NPS) and detective quantum efficiency (DQE).

  4. Design, construction and beam tests of the high resolution uranium scintillator calorimeter for ZEUS

    International Nuclear Information System (INIS)

    Straver, J.A.

    1991-01-01

    HERA will collide protons and electrons with energies up to 820 GeV and 30 GeV respectively. Therefore it allows measurements at momentum transfers (Q) which greatly surpass the investigations carried out so far. This extended range in Q will allow investigation of the interactions between the quarks and leptons at a distance scale of the order of 10 -18 cm. Two detectors are foreseen at HERA H1 and ZEUS. The design of the ZEUS detector is optimized for the study of neutral and charged current interactions. A calorimeter is a detector which absorbs the total incident energy of a particle while generating a signal proportional to this energy. The ZEUS calorimeter is built of alternating layers of dense absorber plates ( 238 U) and active layers of scintillator material with a fast readout system via wavelength shifters, light guides and photomultiplyers. The main subject of this thesis is the description of this calorimeter and its performance. After a short introduction to HERA and the physics topics, the importance of the quality of a calorimeter is pointed out and a brief overview of the ZEUS detector is given. In ch. 3 the principles of high resolution hadron calorimetry and the studies which led to the design of the ZEUS-calorimeter are discussed. Ch. 4 describes the mechanical design of the ZEUS forward calorimeter, the mechanical finite element calculations, and the production of the calorimeter modules at NIKHEF. Finally ch. 6 and 5 show the results of beam tests of the ZEUS forward calorimeter prototypes and the final full size forward calorimeter modules. (author). 59 refs.; 115 figs.; 29 tabs

  5. Grooved windows for scintillation crystals and light pipes of high refractive index

    International Nuclear Information System (INIS)

    Swinehart, C.F.

    1975-01-01

    Scintillation crystals are disclosed which have improved resolution and pulse height. An improved crystal has shallow grooves or spot depressions cut in the window, usually an end surface. Typical grooves are about 1.5 mm wide and about .1 mm deep. The grooves may be either horizontal, generally parallel grooves in spaced apart relationship, or concentric rings in radially spaced apart relationship. A light pipe of high refractive index, such as a crystal of pure sodium iodide, may also be improved with shallow grooves or spot depressions cut in an end surface

  6. Photon statistics in scintillation crystals

    Science.gov (United States)

    Bora, Vaibhav Joga Singh

    Scintillation based gamma-ray detectors are widely used in medical imaging, high-energy physics, astronomy and national security. Scintillation gamma-ray detectors are eld-tested, relatively inexpensive, and have good detection eciency. Semi-conductor detectors are gaining popularity because of their superior capability to resolve gamma-ray energies. However, they are relatively hard to manufacture and therefore, at this time, not available in as large formats and much more expensive than scintillation gamma-ray detectors. Scintillation gamma-ray detectors consist of: a scintillator, a material that emits optical (scintillation) photons when it interacts with ionization radiation, and an optical detector that detects the emitted scintillation photons and converts them into an electrical signal. Compared to semiconductor gamma-ray detectors, scintillation gamma-ray detectors have relatively poor capability to resolve gamma-ray energies. This is in large part attributed to the "statistical limit" on the number of scintillation photons. The origin of this statistical limit is the assumption that scintillation photons are either Poisson distributed or super-Poisson distributed. This statistical limit is often dened by the Fano factor. The Fano factor of an integer-valued random process is dened as the ratio of its variance to its mean. Therefore, a Poisson process has a Fano factor of one. The classical theory of light limits the Fano factor of the number of photons to a value greater than or equal to one (Poisson case). However, the quantum theory of light allows for Fano factors to be less than one. We used two methods to look at the correlations between two detectors looking at same scintillation pulse to estimate the Fano factor of the scintillation photons. The relationship between the Fano factor and the correlation between the integral of the two signals detected was analytically derived, and the Fano factor was estimated using the measurements for SrI2:Eu, YAP

  7. Digital silicon photomultiplier readout of a new fast and bright scintillation crystal (Ce:GFAG)

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Yong-Seok [Department of Bio-convergence Engineering, Korea University, Seoul (Korea, Republic of); Leem, Hyun-Tae [Molecular Imaging Research & Education (MiRe) Laboratory, Department of Electronic Engineering, Sogang University, Seoul (Korea, Republic of); Yamamoto, Seiichi [Department of Medical Technology, Nagoya University Graduate School of Medicine, Nagoya (Japan); Choi, Yong, E-mail: ychoi@sogang.ac.kr [Molecular Imaging Research & Education (MiRe) Laboratory, Department of Electronic Engineering, Sogang University, Seoul (Korea, Republic of); Kamada, Kei [New Industry Creation Hatchery Center (NICHe), Tohoku University, Sendai (Japan); C& A corporation, Sendai (Japan); Yoshikawa, Akira [New Industry Creation Hatchery Center (NICHe), Tohoku University, Sendai (Japan); C& A corporation, Sendai (Japan); Institute for Material Research, Tohoku University, Sendai (Japan); Park, Sang-Geon [Department of Electrical & Electronics, Silla University, Pusan (Korea, Republic of); Yeom, Jung-Yeol, E-mail: jungyeol@korea.ac.kr [Department of Bio-convergence Engineering, Korea University, Seoul (Korea, Republic of); School of Biomedical Engineering, Korea University, Seoul (Korea, Republic of)

    2016-10-01

    A new Gadolinium Fine Aluminum Gallate (Ce:GFAG) scintillation crystal with both high energy resolution and fast timing properties has successfully been grown. Compared to Gd{sub 3}Al{sub 2}Ga{sub 3}O{sub 12} (Ce:GAGG), this new inorganic scintillation crystal has a high luminosity similar to and a faster decay time. In this paper, we report on the timing and energy performance results of the new GFAG scintillation crystal read out with digital silicon photomultipliers (dSiPM) for positron emission tomography (PET) application. The best coincidence resolving time (FWHM) of polished 3×3×5 mm{sup 3} crystals was 223±6 ps for GFAG crystals compared to 396±28 ps for GAGG crystals and 131±3 ps for LYSO crystals respectively. An energy resolution (511 keV peak of Na-22) of 10.9±0.2% was attained with GFAG coupled to dSiPM after correcting for saturation effect, compared to 9.5±0.3% for Ce:GAGG crystals and 11.9±0.4% for LYSO crystals respectively. It is expected that this new scintillator may be competitive in terms of overall properties such as energy resolution, timing resolution and growing (raw material) cost, compared to existing scintillators for positron emission tomography (PET).

  8. Proportional gas scintillation detectors and their applications

    International Nuclear Information System (INIS)

    Petr, I.

    1978-01-01

    The principle is described of a gas proportional scintillation detector and its function. Dependence of Si(Li) and xenon proportional detectors energy resolution on the input window size is given. A typical design is shown of a xenon detector used for X-ray spetrometry at an energy of 277 eV to 5.898 keV and at a gas pressure of 98 to 270 kPa. Gas proportional scintillation detectors show considerable better energy resolution than common proportional counters and even better resolution than semiconductor Si(Li) detectors for low X radiation energies. For detection areas smaller than 25 mm 2 Si(Li) detectors show better resolution, especially for higher X radiation energies. For window areas 25 to 190 mm 2 both types of detectors are equal, for a window area exceeding 190 mm 2 the proportional scintillation detector has higher energy resolution. (B.S.)

  9. Particle detector spatial resolution

    International Nuclear Information System (INIS)

    Perez-Mendez, V.

    1992-01-01

    Method and apparatus for producing separated columns of scintillation layer material, for use in detection of X-rays and high energy charged particles with improved spatial resolution is disclosed. A pattern of ridges or projections is formed on one surface of a substrate layer or in a thin polyimide layer, and the scintillation layer is grown at controlled temperature and growth rate on the ridge-containing material. The scintillation material preferentially forms cylinders or columns, separated by gaps conforming to the pattern of ridges, and these columns direct most of the light produced in the scintillation layer along individual columns for subsequent detection in a photodiode layer. The gaps may be filled with a light-absorbing material to further enhance the spatial resolution of the particle detector. 12 figs

  10. Improvements to well scintillation counters

    International Nuclear Information System (INIS)

    Farukhi, M.R.; Mataraza, G.A.; Wimer, O.D.

    1977-01-01

    This invention relates to the field of ionising radiation detection. It concerns in particular scintillation detectors of the type that is commonly used in conjunction with a photomultiplier tube and that is used for monitoring radiation, for instance in the clinical measurements of isotopes. This invention enables well scintillation counters to be made, characterised by a high efficiency in measuring the thindown rate of radio-pharmaceutical solutions and to resolve the distribution of energy emanating from the radioactive source. It particularly consists in improving the uniformity of the luminous efficiency, the quality of the resolution and the efficiency whilst improving the reception of light [fr

  11. Porous silicon phantoms for high-resolution scintillation imaging

    Energy Technology Data Exchange (ETDEWEB)

    Di Francia, G. [Portici Research Centre, ENEA, Via Vecchio Macello, 80055 Portici, Naples (Italy); Scafe, R. [Casaccia Research Centre, ENEA, 00060 S.Maria di Galeria, Rome (Italy)]. E-mail: scafe@casaccia.enea.it; De Vincentis, G. [Department of Radiological Sciences, University of Rome ' La Sapienza' , V.le Regina Elena, 324, 00161 Rome (Italy); La Ferrara, V. [Portici Research Centre, ENEA, Via Vecchio Macello, 80055 Portici, Naples (Italy); Iurlaro, G. [Casaccia Research Centre, ENEA, 00060 S.Maria di Galeria, Rome (Italy); Nasti, I. [Portici Research Centre, ENEA, Via Vecchio Macello, 80055 Portici, Naples (Italy); Montani, L. [Casaccia Research Centre, ENEA, 00060 S.Maria di Galeria, Rome (Italy); Pellegrini, R. [Department of Experimental Medicine, University of Rome ' La Sapienza' , V.le Regina Elena, 324, 00161 Rome (Italy); Betti, M. [Department of Experimental Medicine, University of Rome ' La Sapienza' , V.le Regina Elena, 324, 00161 Rome (Italy); Martucciello, N. [Portici Research Centre, ENEA, Via Vecchio Macello, 80055 Portici, Naples (Italy); Pani, R. [Department of Experimental Medicine, University of Rome ' La Sapienza' , V.le Regina Elena, 324, 00161 Rome (Italy)

    2006-12-20

    High resolution radionuclide imaging requires phantoms with precise geometries and known activities using either Anger cameras equipped with pinhole collimators or dedicated small animal devices. Porous silicon samples, having areas of different shape and size, can be made and loaded with a radioactive material, obtaining: (a) precise radio-emitting figures corresponding to the porous areas geometry (b) a radioactivity of each figure depending on the pore's specifications, and (c) the same emission energy to be used in true exams. To this aim a sample with porous circular areas has been made and loaded with a {sup 99m}TcO{sub 4} {sup -} solution. Imaging has been obtained using both general purpose and pinhole collimators. This first sample shows some defects that are analyzed and discussed.

  12. R&D proposal to DRDC fast EM calorimeter with excellent photon angular resolution and energy resolution using scintillating noble liquids

    CERN Document Server

    Chen, M; Sumorok, K; Zhang, X; Gaudreau, M P J; Akimov, D Y; Bolozdynya, A I; Churakov, D; Chernyshov, V; Koutchenkov, A; Kovalenko, A; Kuzichev, V F; Lamkov, V A; Lebedenko, V; Gusev, L; Safronov, G A; Sheinkman, V A; Smirnov, G; Krasnokutsky, R N; Shuvalov, R S; Fedyakin, N N; Sushkov, V V; Akopyan, M V; Gougas, Andreas; Pevsner, A; CERN. Geneva. Detector Research and Development Committee

    1993-01-01

    Recent test beam data have shown fast and large signals for LKr, mixed with >1% LXe. Excellent uniformity in LKr and LXe was achieved over a 37 cm long cell. CsI cathode works well inside LKr/LXe with O(1%) resolution at 5 MeV. Precision calibration in-situ has been demonstrated. Scintillating LKr/LXe detectors are sufficiently radiation hard for LHC environment. These new developments simplify the construction of prototype LKr calorimeter, to demonstrate the superior e/gamma energy resolution and the determination of photon direction using longitudinal and transverse segmentations, which are vital for the detection of the multi-photon states. The constant term in the energy resolution is small, the electronics noise is negligible due to the large signal size. The overall pion/electron suppression is expected to be better than 10-4.

  13. Cherenkov and scintillation light separation in organic liquid scintillators

    Energy Technology Data Exchange (ETDEWEB)

    Caravaca, J.; Descamps, F.B.; Land, B.J.; Orebi Gann, G.D. [University of California, Berkeley, CA (United States); Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Yeh, M. [Brookhaven National Laboratory, Upton, NY (United States)

    2017-12-15

    The CHErenkov/Scintillation Separation experiment (CHESS) has been used to demonstrate the separation of Cherenkov and scintillation light in both linear alkylbenzene (LAB) and LAB with 2 g/L of PPO as a fluor (LAB/PPO). This is the first successful demonstration of Cherenkov light detection from the more challenging LAB/PPO cocktail and improves on previous results for LAB. A time resolution of 338 ± 12 ps FWHM results in an efficiency for identifying Cherenkov photons in LAB/PPO of 70 ± 3% and 63 ± 8% for time- and charge-based separation, respectively, with scintillation contamination of 36 ± 5% and 38 ± 4. LAB/PPO data is consistent with a rise time of τ{sub r} = 0.72 ± 0.33 ns. (orig.)

  14. Cherenkov and scintillation light separation in organic liquid scintillators

    International Nuclear Information System (INIS)

    Caravaca, J.; Descamps, F.B.; Land, B.J.; Orebi Gann, G.D.; Yeh, M.

    2017-01-01

    The CHErenkov/Scintillation Separation experiment (CHESS) has been used to demonstrate the separation of Cherenkov and scintillation light in both linear alkylbenzene (LAB) and LAB with 2 g/L of PPO as a fluor (LAB/PPO). This is the first successful demonstration of Cherenkov light detection from the more challenging LAB/PPO cocktail and improves on previous results for LAB. A time resolution of 338 ± 12 ps FWHM results in an efficiency for identifying Cherenkov photons in LAB/PPO of 70 ± 3% and 63 ± 8% for time- and charge-based separation, respectively, with scintillation contamination of 36 ± 5% and 38 ± 4. LAB/PPO data is consistent with a rise time of τ r = 0.72 ± 0.33 ns. (orig.)

  15. High Resolution Sensor for Nuclear Waste Characterization

    International Nuclear Information System (INIS)

    Kanai Shah; William Higgins; Edgar V. Van Loef

    2006-01-01

    Gamma ray spectrometers are an important tool in the characterization of radioactive waste. Important requirements for gamma ray spectrometers used in this application include good energy resolution, high detection efficiency, compact size, light weight, portability, and low power requirements. None of the available spectrometers satisfy all of these requirements. The goal of the Phase I research was to investigate lanthanum halide and related scintillators for nuclear waste clean-up. LaBr 3 :Ce remains a very promising scintillator with high light yield and fast response. CeBr 3 is attractive because it is very similar to LaBr 3 :Ce in terms of scintillation properties and also has the advantage of much lower self-radioactivity, which may be important in some applications. CeBr 3 also shows slightly higher light yield at higher temperatures than LaBr 3 and may be easier to produce with high uniformity in large volume since it does not require any dopants. Among the mixed lanthanum halides, the light yield of LaBr x I 3-x :Ce is lower and the difference in crystal structure of the binaries (LaBr 3 and LaI 3 ) makes it difficult to grow high quality crystals of the ternary as the iodine concentration is increased. On the other hand, LaBr x I 3-x :Ce provides excellent performance. Its light output is high and it provides fast response. The crystal structures of the two binaries (LaBr 3 and LaCl 3 ) are very similar. Overall, its scintillation properties are very similar to those for LaBr 3 :Ce. While the gamma-ray stopping efficiency of LaBr x I 3-x :Ce is lower than that for LaBr 3 :Ce (primarily because the density of LaCl 3 is lower than that of LaBr 3 ), it may be easier to grow large crystals of LaBr x I 3-x :Ce than LaBr 3 :Ce since in some instances (for example, Cd x Zn 1-x Te), the ternary compounds provide increased flexibility in the crystal lattice. Among the new dopants, Eu 2+ and Pr 3+ , tried in LaBr 3 host crystals, the Eu 2+ doped samples exhibited

  16. A new scintillation counter with very fast resolving time (1961); Nouveau compteur a scintillation a tres faible temps de resolution (1961)

    Energy Technology Data Exchange (ETDEWEB)

    Koch, L [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1961-07-01

    The rare gases used as scintillators are characterized by their short time of luminescence and by the linearity of their response as a function of the total energy imparted to the gas by the incident particle. It is possible with these scintillators, when associated with a fast response photomultiplier, to solve certain problems of nuclear physics demanding a linear detector with a very fast resolving time (a few nanoseconds). Two examples of the construction of this apparatus are described. The results obtained and future possibilities are briefly outlined. (author) [French] Les gaz rares utilises comme scintillateurs sont caracterises par leur faible duree de luminescence et par la linearite de leur reponse en fonction de l'energie totale cedee au gaz par la particule incidente. Ces scintillateurs, associes a un photomultiplicateur a une reponse rapide, permettent de resoudre certains problemes de physique nucleaire dans lesquels un detecteur lineaire a tres faible temps de resolution (quelques nanosecondes) se revele indispensable. Deux exemples de realisation sont decrits. Les resultats obtenus et les possibilites futures sont brievement exposes. (auteur)

  17. Structured scintillators for X-ray imaging with micrometre resolution

    DEFF Research Database (Denmark)

    Olsen, Ulrik Lund; Schmidt, Søren; Poulsen, Henning Friis

    2009-01-01

    A 3D X-ray detector for imaging of 30–200 keV photons is described. It comprises a stack of semitransparent structured scintillators, where each scintillator is a regular array of waveguides in silicon, and with pores filled with CsI. The performance of the detector is described theoretically...

  18. A high-resolution detector based on liquid-core scintillating fibres with readout via an electron-bombarded charge-coupled device

    International Nuclear Information System (INIS)

    Cianfarani, C.; Duane, A.; Fabre, J.P.; Frenkel, A.; Golovkin, S.V.; Gorin, A.M.; Harrison, K.; Kozarenko, E.N.; Kushnirenko, A.E.; Ladygin, E.A.; Martellotti, G.; Medvedkov, A.M.; Nass, P.A.; Obudovski, V.P.; Penso, G.; Petukhov, Yu.P.; Siegmund, W.P.; Tyukov, V.E.; Vasilchenko, V.G.

    1994-01-01

    This paper is a presentation of results from tests in a 5 GeV/c hadron beam of detectors based on liquid-core scintillating fibres, each fibre consisting of a glass capillary filled with organic liquid scintillator. Fibre readout was performed via an Electron-Bombarded Charge-Coupled Device (EBCCD) image tube, a novel instrument that combines the functions of a high-gain, gated image intensifier and a Charge-Coupled Device. Using 1-methylnaphthalene doped with 3 g/l of R45 as liquid scintillator, the attenuation lengths obtained for light propagation over distances greater than 16 cm were 1.5 m in fibres of 20 μm core and 1.0 m in fibres of 16 μm core. For particles that crossed the fibres of 20 μm core at distances of ∼1.8 cm and ∼95 cm from the fibres' readout ends, the recorded hit densities were 5.3 mm -1 and 2.5 mm -1 respectively. Using 1-methylnaphthalene doped with 3.6 g/l of R39 as liquid scintillator and fibres of 75 μm core, the hit density obtained for particles that crossed the fibres at a distance of ∼1.8 cm from their readout ends was 8.5 mm -1 . With a specially designed bundle of tapered fibres, having core diameters that smoothly increase from 16 μm to 75 μm, a spatial precision of 6 μm was measured. (orig.)

  19. Timing performance of plastic scintillators of various sizes in a beam test

    International Nuclear Information System (INIS)

    Zhao Li; Jiang Linli; Chinese Acacdemy of Sciences, Beijing; Heng Yuekun; Wu Chong; Zhao Xiaojian; Sun Zhijia; Wu Jinjie; Wang Yifang; Zhao Yuda; Nanjing Univ., Nanjing; Wang Fengmei

    2006-01-01

    The time-of-flight detector of the Beijing Spectrometer III(BES III) is built with long and narrow plastic scintillator bars, with each being 2.3 m long and 6 cm wide. The time resolution of prototypes wrapped with aluminum film has been studied for various thickness of the scintillator using a test beam at the Institute of High Energy Physics in Beijing, China. In this paper, the position-dependent time resolution of the scintillator with a thickness of 4 cm, 5 cm and 6 cm is presented and compared with a Monte Carlo simulation, the results show that the bar with a thickness of 5 cm has the best performance. (authors)

  20. Propagation Diagnostic Simulations Using High-Resolution Equatorial Plasma Bubble Simulations

    Science.gov (United States)

    Rino, C. L.; Carrano, C. S.; Yokoyama, T.

    2017-12-01

    In a recent paper, under review, equatorial-plasma-bubble (EPB) simulations were used to conduct a comparative analysis of the EPB spectra characteristics with high-resolution in-situ measurements from the C/NOFS satellite. EPB realizations sampled in planes perpendicular to magnetic field lines provided well-defined EPB structure at altitudes penetrating both high and low-density regions. The average C/NOFS structure in highly disturbed regions showed nearly identical two-component inverse-power-law spectral characteristics as the measured EPB structure. This paper describes the results of PWE simulations using the same two-dimensional cross-field EPB realizations. New Irregularity Parameter Estimation (IPE) diagnostics, which are based on two-dimensional equivalent-phase-screen theory [A theory of scintillation for two-component power law irregularity spectra: Overview and numerical results, by Charles Carrano and Charles Rino, DOI: 10.1002/2015RS005903], have been successfully applied to extract two-component inverse-power-law parameters from measured intensity spectra. The EPB simulations [Low and Midlatitude Ionospheric Plasma DensityIrregularities and Their Effects on Geomagnetic Field, by Tatsuhiro Yokoyama and Claudia Stolle, DOI 10.1007/s11214-016-0295-7] have sufficient resolution to populate the structure scales (tens of km to hundreds of meters) that cause strong scintillation at GPS frequencies. The simulations provide an ideal geometry whereby the ramifications of varying structure along the propagation path can be investigated. It is well known path-integrated one-dimensional spectra increase the one-dimensional index by one. The relation requires decorrelation along the propagation path. Correlated structure would be interpreted as stochastic total-electron-content (TEC). The simulations are performed with unmodified structure. Because the EPB structure is confined to the central region of the sample planes, edge effects are minimized. Consequently

  1. [Development and evaluation of an improved high-resolution TOFPET camera: TOFPET II: Progress report, 1984-1985

    International Nuclear Information System (INIS)

    Mullani, N.A.

    1985-01-01

    We have been working to improve the quality of barium fluoride scintillators for the fast component and subsequently improve the coincidence timing. We are now able to obtain approximately 400 psec timing and less than 20% energy resolution for barium fluoride using quartz faced photomultiplier tubes. One major problem with the use of barium fluoride and quartz windows on the PMT's, the coupling of the scintillator to the photomultiplier tube. The best available coupling compound is viscasil from GE which is a silicon grease. It is highly efficient for transmitting the 220 nm uv light from the scintillator

  2. Scintillating optical fibers for fine-grained hodoscopes

    International Nuclear Information System (INIS)

    Borenstein, S.R.; Strand, R.C.

    1981-01-01

    Fast detectors with fine spatial resolution will be needed to exploit high event rates at ISABELLE. Scintillating optical fibers for fine grained hodoscopes have been developed by the authors. A commercial manufacturer of optical fibers has drawn and clad PVT scintillator. Detection efficiencies greater than 99% have been achieved for a 1 mm fiber with a PMT over lengths up to 60 cm. Small diameter PMT's and avalanche photodiodes have been tested with the fibers. Further improvements are sought for the fiber and for the APD's sensitivity and coupling efficiency with the fiber

  3. Designing an optimally proportional inorganic scintillator

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Jai, E-mail: jai.singh@cdu.edu.au [School of Engineering and IT, B-Purple-12, Faculty of EHSE, Charles Darwin University, NT 0909 (Australia); Koblov, Alexander [School of Engineering and IT, B-Purple-12, Faculty of EHSE, Charles Darwin University, NT 0909 (Australia)

    2012-09-01

    The nonproportionality observed in the light yield of inorganic scintillators is studied theoretically as a function of the rates of bimolecular and Auger quenching processes occurring within the electron track initiated by a gamma- or X-ray photon incident on a scintillator. Assuming a cylindrical track, the influence of the track radius and concentration of excitations created within the track on the scintillator light yield is also studied. Analysing the calculated light yield a guideline for inventing an optimally proportional scintillator with optimal energy resolution is presented.

  4. Designing an optimally proportional inorganic scintillator

    International Nuclear Information System (INIS)

    Singh, Jai; Koblov, Alexander

    2012-01-01

    The nonproportionality observed in the light yield of inorganic scintillators is studied theoretically as a function of the rates of bimolecular and Auger quenching processes occurring within the electron track initiated by a gamma- or X-ray photon incident on a scintillator. Assuming a cylindrical track, the influence of the track radius and concentration of excitations created within the track on the scintillator light yield is also studied. Analysing the calculated light yield a guideline for inventing an optimally proportional scintillator with optimal energy resolution is presented.

  5. submitter Preparation and luminescence properties of ZnO:Ga – polystyrene composite scintillator

    CERN Document Server

    Burešová, Hana; Turtos, Rosana Martinez; Jarý, Vítězslav; Mihóková, Eva; Beitlerová, Alena; Pjatkan, Radek; Gundacker, Stefan; Auffray, Etiennette; Lecoq, Paul; Nikl, Martin; Čuba, Václav

    2016-01-01

    Highly luminescent ZnO:Ga-polystyrene composite (ZnO:Ga-PS) with ultrafast subnanosecond decay was prepared by homogeneous embedding the ZnO:Ga scintillating powder into the scintillating organic matrix. The powder was prepared by photo-induced precipitation with subsequent calcination in air and Ar/H2 atmospheres. The composite was subsequently prepared by mixing the ZnO:Ga powder into the polystyrene (10 wt% fraction of ZnO:Ga) and press compacted to the 1 mm thick pellet. Luminescent spectral and kinetic characteristics of ZnO:Ga were preserved. Radioluminescence spectra corresponded purely to the ZnO:Ga scintillating phase and emission of polystyrene at 300-350 nm was absent. These features suggest the presence of non-radiative energy transfer from polystyrene host towards the ZnO:Ga scintillating phase which is confirmed by the measurement of X-ray excited scintillation decay with picosecond time resolution. It shows an ultrafast rise time below the time resolution of the experiment (18 ps) and a single-...

  6. A new lutetia-based ceramic scintillator for X-ray imaging

    CERN Document Server

    Lempicki, A; Szupryczynski, P; Lingertat, H; Nagarkar, V V; Tipnis, S V; Miller, S R

    2002-01-01

    We report a new scintillator based on a transparent ceramic of Lu sub 2 O sub 3 :Eu. The material has an extremely high density of 9.4 g/cm sup 3 , a light output comparable to CsI:Tl, and a narrow band emission at 610 nm that falls close to the maximum of the response curve of CCDs. Pixelation of the scintillator to prevent lateral spread of light enhances the spatial and contrast resolution, providing imaging performance that equals or surpasses all other currently known scintillators. Upon further development of readout technologies to take full advantage of its transparency, the new scintillator should play a major role in digital radiographic systems.

  7. Microfluidic Scintillation Detectors for High Energy Physics

    CERN Document Server

    Maoddi, Pietro; Mapelli, Alessandro

    This thesis deals with the development and study of microfluidic scintillation detectors, a technology of recent introduction for the detection of high energy particles. Most of the interest for such devices comes from the use of a liquid scintillator, which entails the possibility of changing the active material in the detector, leading to increased radiation resistance. A first part of the thesis focuses on the work performed in terms of design and modelling studies of novel prototype devices, hinting to new possibilities and applications. In this framework, the simulations performed to validate selected designs and the main technological choices made in view of their fabrication are addressed. The second part of this thesis deals with the microfabrication of several prototype devices. Two different materials were studied for the manufacturing of microfluidic scintillation detectors, namely the SU-8 photosensitive epoxy and monocrystalline silicon. For what concerns the former, an original fabrication appro...

  8. Characterization of Ca co-doped LSO:Ce scintillators coupled to SiPM for PET applications

    International Nuclear Information System (INIS)

    Bisogni, M.G.; Collazuol, G.M.; Marcatili, S.; Melcher, C.L.; Del Guerra, A.

    2011-01-01

    Scintillators suitable for PET applications must be characterized by a high efficiency for gamma-ray detection, determined by a high density and atomic number of the crystal; a fast light signal that allows to achieve a good time resolution and to cope with high counting rates; a high light yield for a good energy and time resolution; a good linearity of the light output as a function of the energy to preserve the intrinsic energy resolution of the scintillator. Recently developed LSO:Ce scintillators, co-doped with Ca, have been produced by the University of Tennessee group. They are characterized by the improved performance of most the above-mentioned characteristics. The crystals, initially tested with PMTs, showed a higher light output, faster light pulse, improved energy resolution and reduced afterglow, as compared to the standard LSO:Ce crystals. Even though the PMTs still represent the gold standard photodetectors, the recently available SiPMs are now valid candidate to replace PMTs in the next generation of PET scanners thanks to their compactness, high spatial resolution performances, low bias operating voltage and, most important for combined PET/MRI systems, insensitivity to static and RF fields. In this work we present the performance of Ca co-doped LSO:Ce samples coupled to SiPMs and PMTs. In particular we have assessed their performances by evaluating the energy and time resolution.

  9. Effects of detector-source distance and detector bias voltage variations on time resolution of general purpose plastic scintillation detectors.

    Science.gov (United States)

    Ermis, E E; Celiktas, C

    2012-12-01

    Effects of source-detector distance and the detector bias voltage variations on time resolution of a general purpose plastic scintillation detector such as BC400 were investigated. (133)Ba and (207)Bi calibration sources with and without collimator were used in the present work. Optimum source-detector distance and bias voltage values were determined for the best time resolution by using leading edge timing method. Effect of the collimator usage on time resolution was also investigated. Copyright © 2012 Elsevier Ltd. All rights reserved.

  10. Collimator trans-axial tomographic scintillation camera

    International Nuclear Information System (INIS)

    Jaszczak, Ronald J.

    1979-01-01

    An improved collimator is provided for a scintillation camera system that employs a detector head for transaxial tomographic scanning. One object of this invention is to significantly reduce the time required to obtain statistically significant data in radioisotope scanning using a scintillation camera. Another is to increase the rate of acceptance of radioactive events to contribute to the positional information obtainable from a radiation source of known strength without sacrificing spatial resolution. A further object is to reduce the necessary scanning time without degrading the images obtained. The collimator described has apertures defined by septa of different radiation transparency. The septa are aligned to provide greater radiation shielding from gamma radiation travelling within planes perpendicular to the cranial-caudal axis and less radiation shielding from gamma radiation travelling within other planes. Septa may also define apertures such that the collimator provides high spatial resolution of gamma rays traveling within planes perpendicular to the cranial-caudal axis and directed at the detector and high radiation sensitivity to gamma radiation travelling other planes and indicated at the detector. (LL)

  11. Comparison of CsI(Tl) and CsI(Na) partially slotted crystals for high-resolution SPECT imaging

    International Nuclear Information System (INIS)

    Giokaris, N.; Loudos, G.; Maintas, D.; Karabarbounis, A.; Lembesi, M.; Spanoudaki, V.; Stiliaris, E.; Boukis, S.; Sakellios, N.; Karakatsanis, N.; Gektin, A.; Boyarintsev, A.; Pedash, V.; Gayshan, V.

    2006-01-01

    Dedicated systems based on Position Sensitive Photomultiplier Tubes (PSPMTs) coupled to scintillators, have been used over the past years for the construction of compact systems, suitable for applications such as small animal imaging and small organs imaging. Most of the proposed systems are based on fully pixelized scintillators. Previous studies have shown that partially slotted scintillators offer a good compromise between cost, energy resolution and spatial resolution. In this work, the performance of two sets of CsI(Tl) and CsI(Na) partially slotted crystals is compared. Initial results show that CsI(Tl) scintillators are more suitable for gamma-ray detection, since their performance in terms of sensitivity, spatial and energy resolution is superior than that of CsI(Na)

  12. Improved Growth Methods for LaBr3 Scintillation Radiation Detectors

    International Nuclear Information System (INIS)

    McGregor, Douglas S.

    2011-01-01

    The objective is to develop advanced materials for deployment as high-resolution gamma ray detectors. Both LaBr3 and CeBr3 are advanced scintillation materials, and will be studied in this research. Prototype devices, in collaboration Sandia National Laboratories, will be demonstrated along with recommendations for mass production and deployment. It is anticipated that improved methods of crystal growth will yield larger single crystals of LaBr3 for deployable room-temperature operated gamma radiation spectrometers. The growth methods will be characterized. The LaBr3 and CeBr3 scintillation crystals will be characterized for light yield, spectral resolution, and for hardness.

  13. The H1 lead/scintillating-fibre calorimeter

    International Nuclear Information System (INIS)

    Appuhn, R.D.; Arndt, C.; Barrelet, E.

    1996-08-01

    The backward region of the H1 detector has been upgraded in order to provide improved measurement of the scattered electron in deep inelastic scattering events. The centerpiece of the upgrade is a high-resolution lead/scintillating-fibre calorimeter. The main design goals of the calorimeter are: good coverage of the region close to the beam pipe, high angular resolution and energy resolution of better than 2% for 30 GeV electrons. The calorimeter should be capable of providing coarse hadronic energy measurement and precise time information to suppress out-of-time background events at the first trigger level. It must be compact due to space restrictions. These requirements were fulfilled by constructing two separate calorimeter sections. The inner electromagnetic section is made of 0.5 mm scintillating plastic fibres embedded in a lead matrix. Its lead-to-fibre ratio is 2.3:1 by volume. The outer hadronic section consists of 1.0 mm diameter fibres with a lead-to-fibre ratio of 3.4:1. The mechanical construction of the new calorimeter and its assembly in the H1 detector are described. (orig.)

  14. The H1 lead/scintillating-fibre calorimeter

    International Nuclear Information System (INIS)

    Appuhn, R.-D.; Arndt, C.; Barrelet, E.

    1997-01-01

    The backward region of the H1 detector has been upgraded in order to provide improved measurement of the scattered electron in deep inelastic scattering events. The centerpiece of the upgrade is a high-resolution lead/scintillating-fibre calorimeter. The main design goals of the calorimeter are: good coverage of the region close to the beam pipe, high angular resolution and energy resolution of better than 2% for 30 GeV electrons. The calorimeter should be capable of providing coarse hadronic energy measurement and precise time information to suppress out-of-time background events at the first trigger level. It must be compact due to space restrictions. These requirements were fulfilled by constructing two separate calorimeter sections. The inner electromagnetic section is made of 0.5 mm scintillating plastic fibres embedded in a lead matrix. Its lead-to-fibre ratio is 2.3:1 by volume. The outer hadronic section consists of 1.0 mm diameter fibres with a lead-to-fibre ratio of 3.4:1. The mechanical construction of the new calorimeter and its assembly in the H1 detector are described. (orig.)

  15. Scintillating plastic optical fiber radiation detectors in high energy particle physics

    International Nuclear Information System (INIS)

    Bross, A.D.

    1991-01-01

    We describe the application of scintillating optical fiber in instrumentation for high energy particle physics. The basic physics of the scintillation process in polymers is discussed first and then we outline the fundamentals of scintillating fiber technology. Fiber performance, optimization, and characterization measurements are given. Detector applications in the areas of particle tracking and particle energy determination are then described. 13 refs., 12 figs

  16. Test beam studies of the light yield, time and coordinate resolutions of scintillator strips with WLS fibers and SiPM readout

    Energy Technology Data Exchange (ETDEWEB)

    Denisov, Dmitri [Fermilab, Batavia IL (United States); Evdokimov, Valery [Institute for High Energy Physics, Protvino (Russian Federation); Lukić, Strahinja; Ujić, Predrag [Vinča Institute, University of Belgrade (Serbia)

    2017-03-11

    Prototype scintilator+WLS strips with SiPM readout for large muon detection systems were tested in the muon beam of the Fermilab Test Beam Facility. Light yield of up to 137 photoelectrons per muon per strip has been observed , as well as time resolution of 330 ps and position resolution along the strip of 5.4 cm.

  17. Scintillation efficiency and X-ray imaging with the RE-Doped LuAG thin films grown by liquid phase epitaxy

    International Nuclear Information System (INIS)

    Tous, Jan; Blazek, Karel; Kucera, Miroslav; Nikl, Martin; Mares, Jiri A.

    2012-01-01

    Very thin scintillator imaging plates have recently become of great interest. In high resolution X-ray radiography, very thin scintillator layers of about 5–20 μm are used to achieve 2D-spatial resolutions below 1 μm. Thin screens can be prepared by mechanical polishing from single crystals or by epitaxial growth on single-crystal substrates using the Liquid Phase Epitaxy technique (LPE). Other types of screens (e.g. deposited powder) do no reach required spatial resolutions. This work compares LPE-grown YAG and LuAG scintillator films doped with different rare earth ions (Cerium, Terbium and Europium). Two different fluxes were used in the LPE growth procedure. These LPE films are compared to YAG:Ce and LuAG:Ce screens made from bulk single crystals. Relative light yield was detected by a highly sensitive CCD camera. Scintillator screens were excited by a micro-focus X-ray source and the generated light was gathered by the CCD camera’s optical system. Scintillator 2D-homogeneity is examined in an X-ray imaging setup also using the CCD camera.

  18. Some possible improvements in scintillation calorimeters

    International Nuclear Information System (INIS)

    Lorenz, E.

    1985-03-01

    Two ideas for improvements of scintillation calorimeters will be presented: a) improved readout of scintillating, totally active electromagnetic calorimeters with combinations of silicon photodiodes and fluorescent panel collectors, b) use of time structure analysis on calorimetry, both for higher rate applications and improved resolution for hadron calorimeters. (orig.)

  19. Alpha liquid scintillation counting: past, present, and future

    International Nuclear Information System (INIS)

    McDowell, W.J.

    1979-01-01

    Beta liquid scintillation counting has been used for about 30 years, and its effectiveness for alpha particles has been known for almost that long; however, the technique has not been widely applied to alpha particle detection because of poor energy resolution, high background, and variable interference from beta and gamma radiation. Beginning with the work of Horrocks in the early 1960s, improvements in energy resolution and background rejection have been made. Further developments at Oak Ridge National Laboratory over the past 10 to 12 years have resulted in improved methods of sample preparation (using liquid-liquid extraction methods to isolate the sample and introduce it into the scintillator) and better instrumentation, including electronic rejection of beta and gamma pulses. Energy resolutions of 200- to 300-keV FWHM and background counts of 0.01 cpm are now routine. Alpha liquid scintillation spectrometry is now suitable for a wide range of applications, from the accurate quantitative determination of relatively large amounts of known nuclides in laboratory-generated samples to the detection and identification of very small, subpicocurie amounts of alpha emitters in environmental-type samples. Suitable nuclide separation procedures, sample preparation methods, and instrument configurations are outlined for a variety of analyses

  20. Advantages of GSO Scintillator in Imaging and Law Level Gamma-ray Spectroscopy

    CERN Document Server

    Sharaf, J

    2002-01-01

    The single GSO crystal is an excellent scintillation material featuring a high light yield and short decay time for gamma-ray detection. Its performance characteristics were investigated and directly compared to those of BGO. For this purpose, the two scintillators are cut into small crystals of approximately 4*4*10 mm sup 3 and mounted on a PMT. Energy resolution, detection efficiency and counting precision have been measured for various photon energies. In addition to this spectroscopic characterization, the imaging performance of GSO was studied using a scanning rig. The modulation transfer function was calculated and the spatial resolution evaluated by measurements of the detector's point spread function. It is shown that there exists some source intensity for which the two scintillators yield identical precision for identical count time. Below this intensity, the GSO is superior to the BGO detector. The presented properties of GSO suggest potential applications of this scintillator in gamma-ray spectrosc...

  1. Time resolution in scintillator based detectors for positron emission tomography

    International Nuclear Information System (INIS)

    Gundacker, S.

    2014-01-01

    In the domain of medical photon detectors L(Y)SO scintillators are used for positron emission tomography (PET). The interest for time of flight (TOF) in PET is increasing since measurements have shown that new crystals like L(Y)SO coupled to state of the art photodetectors, e.g. silicon photomultipliers (SiPM), can reach coincidence time resolutions (CTRs) of far below 500ps FWHM. To achieve these goals it is important to study the processe in the whole detection chain, i.e. the high energy particle or gamma interaction in the crystal, the scintillation process itself, the light propagation in the crystal with the light transfer to the photodetector, and the electronic readout. In this thesis time resolution measurements for a PET like system are performed in a coincidence setup utilizing the ultra fast amplifier discriminator NINO. We found that the time-over-threshold energy information provided by NINO shows a degradation in energy resolution for higher SiPM bias voltages. This is a consequence of the increasing dark count rate (DCR) of the SiPM with higher bias voltages together with the exponential decay of the signal. To overcome this problem and to operate the SiPM at its optimum voltage in terms of timing we developed a new electronic board that employs NINO only as a low noise leading edge discriminator together with an analog amplifier which delivers the energy information. With this new electronic board we indeed improved the measured CTR by about 15%. To study the limits of time resolution in more depth we measured the CTR with 2x2x3mm3 LSO:Ce codoped 0.4%Ca crystals coupled to commercially available SiPMs (Hamamatsu S10931-50P MPPC) and achieved a CTR of 108±5ps FWHM at an energy of 511keV. We determined the influence of the data acquisition system and the electronics on the CTR to be 27±2ps FWHM and thus negligible. To quantitatively understand the measured values, we developed a Monte Carlo simulation tool in MATLAB that incorporates the timing

  2. Evaluation and optimization of the High Resolution Research Tomograph (HRRT)

    International Nuclear Information System (INIS)

    Knoess, C.

    2004-01-01

    Positron Emission Tomography (PET) is an imaging technique used in medicine to determine qualitative and quantitative metabolic parameters in vivo. The High Resolution Research Tomograph (HRRT) is a new high resolution tomograph that was designed for brain studies (312 mm transaxial field-of-view (FOV), 252 mm axial FOV). The detector blocks are arranged in a quadrant sharing design and consist of two crystal layers with dimensions of 2.1 mm x 2.1 mm x 7.5 mm. The main detector material is the newly developed scintillator lutetium oxyorthosilicate (LSO). Events from the different crystal layers are distinguished by Pulse Shape Discrimination (PSD) to gain Depth of Interaction (DOI) information. This will improve the spatial resolution, especially at the edges of the FOV. A prototype of the tomograph was installed at the Max-Planck Institute for Neurological Research in Cologne, Germany in 1999 and was evaluated with respect to spatial resolution, sensitivity, scatter fraction, and count rate behavior. These performance measurements showed that this prototype provided a spatial resolution of around 2.5 mm in a volume big enough to contain the human brain. A comparison with a single layer HRRT prototype showed a 10% worsening of the resolution, despite the fact that DOI was used. Without DOI, the resolution decreased considerably. The sensitivity, as measured with a 22 Na point source, was 46.5 cps/kBq for an energy window of 350-650 keV and 37.9 cps/kBq for an energy window of 400-650 keV, while the scatter fractions were 56% for 350-650 keV and 51% for 400-650 keV, respectively. A daily quality check was developed and implemented that uses the uniform, natural radioactive background of the scintillator material LSO. In 2001, the manufacturer decided to build a series of additional HRRT scanners to try to improve the design (detector electronics, transmission source design, and shielding against out-of-FOV activity) and to eliminate problems (difficult detector

  3. Cerium doped lanthanum halides: fast scintillators for medical imaging

    International Nuclear Information System (INIS)

    Selles, O.

    2006-12-01

    This work is dedicated to two recently discovered scintillating crystals: cerium doped lanthanum halides (LaCl 3 :Ce 3+ and LaBr 3 :Ce 3+ ).These scintillators exhibit interesting properties for gamma detection, more particularly in the field of medical imaging: a short decay time, a high light yield and an excellent energy resolution. The strong hygroscopicity of these materials requires adapting the usual experimental methods for determining physico-chemical properties. Once determined, these can be used for the development of the industrial manufacturing process of the crystals. A proper comprehension of the scintillation mechanism and of the effect of defects within the material lead to new possible ways for optimizing the scintillator performance. Therefore, different techniques are used (EPR, radioluminescence, laser excitation, thermally stimulated luminescence). Alongside Ce 3+ ions, self-trapped excitons are involved in the scintillation mechanism. Their nature and their role are detailed. The knowledge of the different processes involved in the scintillation mechanism leads to the prediction of the effect of temperature and doping level on the performance of the scintillator. A mechanism is proposed to explain the thermally stimulated luminescence processes that cause slow components in the light emission and a loss of light yield. Eventually the study of afterglow reveals a charge transfer to deep traps involved in the high temperature thermally stimulated luminescence. (author)

  4. Thin-film-based scintillators for hard x-ray microimaging detectors: the ScinTAX Project

    Science.gov (United States)

    Rack, A.; Cecilia, A.; Douissard, P.-A.; Dupré, K.; Wesemann, V.; Baumbach, T.; Couchaud, M.; Rochet, X.; Riesemeier, H.; Radtke, M.; Martin, T.

    2014-09-01

    The project ScinTAX developed novel thin scintillating films for the application in high performance X-ray imaging and subsequent introduced new X-ray detectors to the market. To achieve this aim lutetium orthosilicate (LSO) scintillators doped with different activators were grown successfully by liquid phase epitaxy. The high density of LSO (7.4 g/cm3), the effective atomic number (65.2) and the high light yield make this scintillator highly applicable for indirect X-ray detection in which the ionizing radiation is converted into visible light and then registered by a digital detector. A modular indirect detection system has been developed to fully exploit the potential of this thin film scintillator for radiographic and tomographic imaging. The system is compatible for high-resolution imaging with moderate dose as well as adaptable to intense high-dose applications where radiation hard microimaging detectors are required. This proceedings article shall review the achieved performances and technical details on this high-resolution detector system which is now available. A selected example application demonstrates the great potential of the optimized detector system for hard X-ray microimaging, i.e. either to improve image contrast due to the availability of efficient thin crystal films or to reduce the dose to the sample.

  5. DETECTORS AND EXPERIMENTAL METHODS: Studies of a scintillator-bar detector for a neutron wall at an external target facility

    Science.gov (United States)

    Yu, Yu-Hong; Xu, Hua-Gen; Xu, Hu-Shan; Zhan, Wen-Long; Sun, Zhi-Yu; Guo, Zhong-Yan; Hu, Zheng-Guo; Wang, Jian-Song; Chen, Jun-Ling; Zheng, Chuan

    2009-07-01

    To achieve a better time resolution of a scintillator-bar detector for a neutron wall at the external target facility of HIRFL-CSR, we have carried out a detailed study of the photomultiplier, the wrapping material and the coupling media. The timing properties of a scintillator-bar detector have been studied in detail with cosmic rays using a high and low level signal coincidence. A time resolution of 80 ps has been achieved in the center of the scintillator-bar detector.

  6. Characterization of the Ionospheric Scintillations at High Latitude using GPS Signal

    Science.gov (United States)

    Mezaoui, H.; Hamza, A. M.; Jayachandran, P. T.

    2013-12-01

    Transionospheric radio signals experience both amplitude and phase variations as a result of propagation through a turbulent ionosphere; this phenomenon is known as ionospheric scintillations. As a result of these fluctuations, Global Positioning System (GPS) receivers lose track of signals and consequently induce position and navigational errors. Therefore, there is a need to study these scintillations and their causes in order to not only resolve the navigational problem but in addition develop analytical and numerical radio propagation models. In order to quantify and qualify these scintillations, we analyze the probability distribution functions (PDFs) of L1 GPS signals at 50 Hz sampling rate using the Canadian High arctic Ionospheric Network (CHAIN) measurements. The raw GPS signal is detrended using a wavelet-based technique and the detrended amplitude and phase of the signal are used to construct probability distribution functions (PDFs) of the scintillating signal. The resulting PDFs are non-Gaussian. From the PDF functional fits, the moments are estimated. The results reveal a general non-trivial parabolic relationship between the normalized fourth and third moments for both the phase and amplitude of the signal. The calculated higher-order moments of the amplitude and phase distribution functions will help quantify some of the scintillation characteristics and in the process provide a base for forecasting, i.e. develop a scintillation climatology model. This statistical analysis, including power spectra, along with a numerical simulation will constitute the backbone of a high latitude scintillation model.

  7. A micro-machined retro-reflector for improving light yield in ultra-high-resolution gamma cameras

    NARCIS (Netherlands)

    Heemskerk, J.W.T.; Korevaar, M.A.N.; Kreuger, R.; Ligtvoet, C.M.; Schotanus, P.; Beekman, F.J.

    2009-01-01

    High-resolution imaging of x-ray and gamma-ray distributions can be achieved with cameras that use charge coupled devices (CCDs) for detecting scintillation light flashes. The energy and interaction position of individual gamma photons can be determined by rapid processing of CCD images of

  8. Scintillation Reduction using Conjugate-Plane Imaging (Abstract)

    Science.gov (United States)

    Vander Haagen, G. A.

    2017-12-01

    (Abstract only) All observatories are plagued by atmospheric turbulence exhibited as star scintillation or "twinkle" whether a high altitude adaptive optics research or a 30-cm amateur telescope. It is well known that these disturbances are caused by wind and temperature-driven refractive gradients in the atmosphere and limit the ultimate photometric resolution of land-based facilities. One approach identified by Fuchs (1998) for scintillation noise reduction was to create a conjugate image space at the telescope and focus on the dominant conjugate turbulent layer within that space. When focused on the turbulent layer little or no scintillation exists. This technique is described whereby noise reductions of 6 to 11/1 have been experienced with mathematical and optical bench simulations. Discussed is a proof-of-principle conjugate optical train design for an 80-mm, f7 telescope.

  9. Inorganic scintillators for detector systems physical principles and crystal engineering

    CERN Document Server

    Lecoq, Paul; Korzhik, Mikhail

    2017-01-01

    This second edition features new chapters highlighting advances in our understanding of the behavior and properties of scintillators, and the discovery of new families of materials with light yield and excellent energy resolution very close to the theoretical limit. The book focuses on the discovery of next-generation scintillation materials and on a deeper understanding of fundamental processes. Such novel materials with high light yield as well as significant advances in crystal engineering offer exciting new perspectives. Most promising is the application of scintillators for precise time tagging of events, at the level of 100 ps or higher, heralding a new era in medical applications and particle physics. Since the discovery of the Higgs Boson with a clear signature in the lead tungstate scintillating blocks of the CMS Electromagnetic Calorimeter detector, the current trend in particle physics is toward very high luminosity colliders, in which timing performance will ultimately be essential to mitigating...

  10. Scintillation Counters

    Science.gov (United States)

    Bell, Zane W.

    Scintillators find wide use in radiation detection as the detecting medium for gamma/X-rays, and charged and neutral particles. Since the first notice in 1895 by Roentgen of the production of light by X-rays on a barium platinocyanide screen, and Thomas Edison's work over the following 2 years resulting in the discovery of calcium tungstate as a superior fluoroscopy screen, much research and experimentation have been undertaken to discover and elucidate the properties of new scintillators. Scintillators with high density and high atomic number are prized for the detection of gamma rays above 1 MeV; lower atomic number, lower-density materials find use for detecting beta particles and heavy charged particles; hydrogenous scintillators find use in fast-neutron detection; and boron-, lithium-, and gadolinium-containing scintillators are used for slow-neutron detection. This chapter provides the practitioner with an overview of the general characteristics of scintillators, including the variation of probability of interaction with density and atomic number, the characteristics of the light pulse, a list and characteristics of commonly available scintillators and their approximate cost, and recommendations regarding the choice of material for a few specific applications. This chapter does not pretend to present an exhaustive list of scintillators and applications.

  11. Development of Omnidirectional Gamma-imager with Stacked Scintillators

    International Nuclear Information System (INIS)

    Takahashi, Tone; Kawarabayashi, Jun; Tomita, Hideki; Iguchi, Tetsuo; Takada, Eiji

    2013-06-01

    In the severe accident at nuclear power plant, a rapid measurement of radioactive fallout is required. So we have developed a Compton imager with high efficiency and omni-directional sensitivity. Three dimensional position resolutions were evaluated about several kinds of scintillators. The all-directional imaging was demonstrated by the simulation of detection of 137 Cs point source. Imaging quality with angle resolution of 28 deg. and detection efficiency of 1.1% was estimated. (authors)

  12. A high-spatial-resolution three-dimensional detector array for 30-200 keV X-rays based on structured scintillators

    DEFF Research Database (Denmark)

    Olsen, Ulrik Lund; Schmidt, Søren; Poulsen, Henning Friis

    2008-01-01

    A three-dimensional X-ray detector for imaging 30-200 keV photons is described. It comprises a set of semi-transparent structured scintillators, where each scintillator is a regular array of waveguides in silicon, and with pores filled with CsI. The performance of the detector is described...

  13. Ionosphere Scintillation at Low and High Latitudes (Modelling vs Measurement)

    Science.gov (United States)

    Béniguel, Yannick

    2016-04-01

    This paper will address the problem of scintillations characteristics, focusing on the parameters of interest for a navigation system. Those parameters are the probabilities of occurrence of simultaneous fading, the bubbles surface at IPP level, the cycle slips and the fades duration statistics. The scintillation characteristics obtained at low and high latitudes will be compared. These results correspond to the data analysis performed after the ESA Monitor ionosphere measurement campaign [1], [2]. A second aspect of the presentation will be the modelling aspect. It has been observed that the phase scintillation dominates at high latitudes while the intensity scintillation dominates at low latitudes. The way it can be reproduced and implemented in a propagation model (e.g. GISM model [3]) will be presented. Comparisons of measurements with results obtained by modelling will be presented on some typical scenarios. References [1] R. Prieto Cerdeira, Y. Beniguel, "The MONITOR project: architecture, data and products", Ionospheric Effects Symposium, Alexandria (Va), May 2011 [2] Y. Béniguel, R Orus-Perez , R. Prieto-Cerdeira , S. Schlueter , S. Scortan, A. Grosu "MONITOR 2: ionospheric monitoring network in support to SBAS and other GNSS and scientific purposes", IES Conference, Alexandria (Va), May 2015-05-22 [3] Y. Béniguel, P. Hamel, "A Global Ionosphere Scintillation Propagation Model for Equatorial Regions", Journal of Space Weather Space Climate, 1, (2011), doi: 10.1051/swsc/2011004

  14. Measurement of gamma quantum interaction point in plastic scintillator with WLS strips

    Energy Technology Data Exchange (ETDEWEB)

    Smyrski, J., E-mail: smyrski@if.uj.edu.pl [Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, S. Łojasiewicza 11, 30-348 Cracow (Poland); Alfs, D.; Bednarski, T.; Białas, P.; Czerwiński, E.; Dulski, K.; Gajos, A.; Głowacz, B.; Gupta-Sharma, N. [Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, S. Łojasiewicza 11, 30-348 Cracow (Poland); Gorgol, M.; Jasińska, B. [Department of Nuclear Methods, Institute of Physics, Maria Curie-Sklodowska University, 20-031 Lublin (Poland); Kajetanowicz, M.; Kamińska, D.; Korcyl, G. [Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, S. Łojasiewicza 11, 30-348 Cracow (Poland); Kowalski, P. [Świerk Computing Centre, National Centre for Nuclear Research, 05-400 Otwock-Świerk (Poland); Krzemień, W. [High Energy Department, National Centre for Nuclear Research, 05-400 Otwock-Świerk (Poland); Krawczyk, N.; Kubicz, E.; Mohammed, M.; Niedźwiecki, Sz. [Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, S. Łojasiewicza 11, 30-348 Cracow (Poland); and others

    2017-04-11

    The feasibility of measuring the aśxial coordinate of a gamma quantum interaction point in a plastic scintillator bar via the detection of scintillation photons escaping from the scintillator with an array of wavelength-shifting (WLS) strips is demonstrated. Using a test set-up comprising a BC-420 scintillator bar and an array of sixteen BC-482A WLS strips we achieved a spatial resolution of 5 mm (σ) for annihilation photons from a {sup 22}Na isotope. The studied method can be used to improve the spatial resolution of a plastic-scintillator-based PET scanner which is being developed by the J-PET collaboration.

  15. Ionospheric Scintillation Effects on GPS

    Science.gov (United States)

    Steenburgh, R. A.; Smithtro, C.; Groves, K.

    2007-12-01

    . Ionospheric scintillation of Global Positioning System (GPS) signals threatens navigation and military operations by degrading performance or making GPS unavailable. Scintillation is particularly active, although not limited to, a belt encircling the earth within 20 degrees of the geomagnetic equator. As GPS applications and users increases, so does the potential for detrimental impacts from scintillation. We examined amplitude scintillation data spanning seven years from Ascension Island, U.K.; Ancon, Peru; and Antofagasta, Chile in the Atlantic/Americas longitudinal sector at as well as data from Parepare, Indonesia; Marak Parak, Malaysia; Pontianak, Indonesia; Guam; and Diego Garcia, U.K.; in the Pacific longitudinal sector. From these data, we calculate percent probability of occurrence of scintillation at various intensities described by the S4 index. Additionally, we determine Dilution of Precision at one minute resolution. We examine diurnal, seasonal and solar cycle characteristics and make spatial comparisons. In general, activity was greatest during the equinoxes and solar maximum, although scintillation at Antofagasta, Chile was higher during 1998 rather than at solar maximum.

  16. R&D of the CEPC scintillator-tungsten ECAL

    Science.gov (United States)

    Dong, M. Y.

    2018-03-01

    The circular electron and positron collider (CEPC) was proposed as a future Higgs factory. To meet the physics requirements, a particle flow algorithm-oriented calorimeter system with high energy resolution and precise reconstruction is considered. A sampling calorimeter with scintillator-tungsten sandwich structure is selected as one of the electromagnetic calorimeter (ECAL) options due to its good performance and relatively low cost. We present the design, the test and the optimization of the scintillator module read out by silicon photomultiplier (SiPM), including the design and the development of the electronics. To estimate the performance of the scintillator and SiPM module for particles with different energy, the beam test of a mini detector prototype without tungsten shower material was performed at the E3 beams in Institute of High Energy Physics (IHEP). The results are consistent with the expectation. These studies provide a reference and promote the development of particle flow electromagnetic calorimeter for the CEPC.

  17. Response function measurement of plastic scintillator for high energy neutrons

    International Nuclear Information System (INIS)

    Sanami, Toshiya; Ban, Syuichi; Takahashi, Kazutoshi; Takada, Masashi

    2003-01-01

    The response function and detection efficiency of 2''φ x 2''L plastic (PilotU) and NE213 liquid (2''NE213) scintillators, which were used for the measurement of secondary neutrons from high energy electron induced reactions, were measured at Heavy Ion Medical Accelerator in Chiba (HIMAC). High energy neutrons were produced via 400 MeV/n C beam bombardment on a thick graphite target. The detectors were placed at 15 deg with respect to C beam axis, 5 m away from the target. As standard, a 5''φ x 5''L NE213 liquid scintillator (5''NE213) was also placed at same position. Neutron energy was determined by the time-of-flight method with the beam pickup scintillator in front of the target. In front of the detectors, veto scintillators were placed to remove charged particle events. All detector signals were corrected with list mode event by event. We deduce neutron spectrum for each detectors. The efficiency curves for pilotU and 2''NE213 were determined on the bases of 5 N E213 neutron spectrum and its efficiency calculated by CECIL code. (author)

  18. Cerenkov counting and Cerenkov-scintillation counting with high refractive index organic liquids using a liquid scintillation counter

    International Nuclear Information System (INIS)

    Wiebe, L.I.; Helus, F.; Maier-Borst, W.

    1978-01-01

    18 F and 14 C radioactivity was measured in methyl salicylate (MS), a high refractive index hybrid Cherenkov-scintillation generating medium, using a liquid scintillation counter. At concentrations of up to 21.4%, in MS, dimethyl sulfoxide (DMSO) quenched 14 C fluorescence, and with a 10-fold excess of DMSO over MS, 18 F count rates were reduced below that for DMSO alone, probably as a result of concentration-independent self-quenching due to 'dark-complex' formation. DMSO in lower concentrations did not reduce the counting efficiency of 18 F in MS. Nitrobenzene was a concentration-dependent quencher for both 14 C and 18 F in MS. Chlorobenzene (CB) and DMSO were both found to be weak Cherenkov generators with 18 F. Counting efficiencies for 18 F in MS, CB, and DMSO were 50.3, 7.8 and 4.3% respectively in the coincidence counting mode, and 58.1, 13.0 and 6.8% in the singles mode. 14 C efficiencies were 14.4 and 22.3% for coincidence and singles respectively, and 15.3 and 42.0% using a modern counter designed for coincidence and single photon counting. The high 14 C and 18 F counting efficiency in MS are discussed with respect to excitation mechanism, on the basis of quench and channels ratios changes observed. It is proposed that MS functions as an efficient Cherenkov-scintillation generator for high-energy beta emitters such as 18 F, and as a low-efficiency scintillator for weak beta emitting radionuclides such as 14 C. (author)

  19. Scintillation {gamma} spectrography. Physical principles. Apparatus. Operation; Spectrographie {gamma} a scintillations. Principes physiques. Appareillage. Utilisation

    Energy Technology Data Exchange (ETDEWEB)

    Julliot, C. [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1960-07-01

    The scintillation detector forms the main part of the instrument used, the electronic unit presenting the results produced. After a brief description of the process of {gamma} photon absorption in the material, the particular case of NaI (T1), the scintillator used, is examined. The intensity of the scintillation caused by {gamma} ray absorption and the characteristics of the photomultiplier play a determining part in the energy resolution of the instrument. For the {gamma} recording spectrograph, we show to what extent the technique for using the electronic unit can modify the results. A detailed description is given of the activity measurement of a {gamma}-emitting radioelement by the spectrographic method. (author) [French] Dans l'appareillage utilise, le detecteur a scintillations constitue la piece maitresse, l'ensemble electronique presente les resultats issus du detecteur. Apres avoir brievement decrit le processus d'absorption des photons {gamma} dans la matiere, nous examinons le cas particulier du NaI(T1), le scintillateur utilise. L'intensite de la scintillation provoque par l'absorption des rayons {gamma} et les caracteristiques du photomultiplicateur jouent un role determinant dans la resolution en energie de l'appareil. Pour le spectrographe {gamma} enregistreur, nous indiquons dans quelle mesure la technique d'utilisation de l'ensemble electronique peut modifier les resultats. La-mesure de l'activite d'un radioelement emetteur {gamma} par spectrographie fait l'objet d'une description detaillee. (auteur)

  20. Scintillation {gamma} spectrography. Physical principles. Apparatus. Operation; Spectrographie {gamma} a scintillations. Principes physiques. Appareillage. Utilisation

    Energy Technology Data Exchange (ETDEWEB)

    Julliot, C [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1960-07-01

    The scintillation detector forms the main part of the instrument used, the electronic unit presenting the results produced. After a brief description of the process of {gamma} photon absorption in the material, the particular case of NaI (T1), the scintillator used, is examined. The intensity of the scintillation caused by {gamma} ray absorption and the characteristics of the photomultiplier play a determining part in the energy resolution of the instrument. For the {gamma} recording spectrograph, we show to what extent the technique for using the electronic unit can modify the results. A detailed description is given of the activity measurement of a {gamma}-emitting radioelement by the spectrographic method. (author) [French] Dans l'appareillage utilise, le detecteur a scintillations constitue la piece maitresse, l'ensemble electronique presente les resultats issus du detecteur. Apres avoir brievement decrit le processus d'absorption des photons {gamma} dans la matiere, nous examinons le cas particulier du NaI(T1), le scintillateur utilise. L'intensite de la scintillation provoque par l'absorption des rayons {gamma} et les caracteristiques du photomultiplicateur jouent un role determinant dans la resolution en energie de l'appareil. Pour le spectrographe {gamma} enregistreur, nous indiquons dans quelle mesure la technique d'utilisation de l'ensemble electronique peut modifier les resultats. La-mesure de l'activite d'un radioelement emetteur {gamma} par spectrographie fait l'objet d'une description detaillee. (auteur)

  1. 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.)

  2. Central Tracking Detector Based on Scintillating Fibres

    CERN Multimedia

    2002-01-01

    Scintillating fibres form a reasonable compromise for central tracking detectors in terms of price, resolution, response time, occupancy and heat production. \\\\ \\\\ New fluorescents with large Stokes shifts have been produced, capable of working without wavelength shifters. Coherent multibundles have been developed to achieve high packing fractions. Small segments of tracker shell have been assembled and beam tests have confirmed expectations on spatial resolution. An opto-electronic delay line has been designed to delay the track patterns and enable coincidences with a first level trigger. Replacement of the conventional phosphor screen anode with a Si pixel chip is achieved. This tube is called ISPA-tube and has already been operated in beam tests with a scintillating fibres tracker. \\\\ \\\\ The aim of the proposal is to improve hit densities for small diameter fibres by increasing the fraction of trapped light, by reducing absorption and reflection losses, by reflecting light at the free fibre end, and by inc...

  3. Scintillators

    International Nuclear Information System (INIS)

    Cusano, D.A.; Holub, F.F.; Prochazka, S.

    1979-01-01

    Scintillator bodies comprising phosphor materials and having high optical translucency with low light absorption, and methods of making the scintillator bodies, are described. Fabrication methods include (a) a hot-pressing process, (b) cold-pressing followed by sintering, (c) controlled cooling from a melt, and (d) hot-forging. The scintillator bodies that result are easily machined to desired shapes and sizes. Suitable phosphors include BaFCl:Eu, LaOBr:Tb, CsI:Tl, CaWO 4 and CdWO 4 . (U.K.)

  4. Comparison of polystyrene scintillator fiber array and monolithic polystyrene for neutron imaging and radiography

    Energy Technology Data Exchange (ETDEWEB)

    Simpson, R., E-mail: raspberry@lanl.gov; Cutler, T. E.; Danly, C. R.; Espy, M. A.; Goglio, J. H.; Hunter, J. F.; Madden, A. C.; Mayo, D. R.; Merrill, F. E.; Nelson, R. O.; Swift, A. L.; Wilde, C. H.; Zocco, T. G. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

    2016-11-15

    The neutron imaging diagnostic at the National Ignition Facility has been operating since 2011 generating neutron images of deuterium-tritium (DT) implosions at peak compression. The current design features a scintillating fiber array, which allows for high imaging resolution to discern small-scale structure within the implosion. In recent years, it has become clear that additional neutron imaging systems need to be constructed in order to provide 3D reconstructions of the DT source and these additional views need to be on a shorter line of sight. As a result, there has been increased effort to identify new image collection techniques that improve upon imaging resolution for these next generation neutron imaging systems, such as monolithic deuterated scintillators. This work details measurements performed at the Weapons Neutron Research Facility at Los Alamos National Laboratory that compares the radiographic abilities of the fiber scintillator with a monolithic scintillator, which may be featured in a future short line of sight neutron imaging systems.

  5. TH-CD-201-10: Highly Efficient Synchronized High-Speed Scintillation Camera System for Measuring Proton Range, SOBP and Dose Distributions in a 2D-Plane

    International Nuclear Information System (INIS)

    Goddu, S; Sun, B; Grantham, K; Zhao, T; Zhang, T; Bradley, J; Mutic, S

    2016-01-01

    Purpose: Proton therapy (PT) delivery is complex and extremely dynamic. Therefore, quality assurance testing is vital, but highly time-consuming. We have developed a High-Speed Scintillation-Camera-System (HS-SCS) for simultaneously measuring multiple beam characteristics. Methods: High-speed camera was placed in a light-tight housing and dual-layer neutron shield. HS-SCS is synchronized with a synchrocyclotron to capture individual proton-beam-pulses (PBPs) at ∼504 frames/sec. The PBPs from synchrocyclotron trigger the HS-SCS to open its shutter for programmed exposure-time. Light emissions within 30×30×5cm3 plastic-scintillator (BC-408) were captured by a CCD-camera as individual images revealing dose-deposition in a 2D-plane with a resolution of 0.7mm for range and SOBP measurements and 1.67mm for profiles. The CCD response as well as signal to noise ratio (SNR) was characterized for varying exposure times, gains for different light intensities using a TV-Optoliner system. Software tools were developed to analyze ∼5000 images to extract different beam parameters. Quenching correction-factors were established by comparing scintillation Bragg-Peaks with water scanned ionization-chamber measurements. Quenching corrected Bragg-peaks were integrated to ascertain proton-beam range (PBR), width of Spared-Out-Bragg-Peak (MOD) and distal

  6. TH-CD-201-10: Highly Efficient Synchronized High-Speed Scintillation Camera System for Measuring Proton Range, SOBP and Dose Distributions in a 2D-Plane

    Energy Technology Data Exchange (ETDEWEB)

    Goddu, S; Sun, B; Grantham, K; Zhao, T; Zhang, T; Bradley, J; Mutic, S [Washington University School of Medicine, Saint Louis, MO (United States)

    2016-06-15

    Purpose: Proton therapy (PT) delivery is complex and extremely dynamic. Therefore, quality assurance testing is vital, but highly time-consuming. We have developed a High-Speed Scintillation-Camera-System (HS-SCS) for simultaneously measuring multiple beam characteristics. Methods: High-speed camera was placed in a light-tight housing and dual-layer neutron shield. HS-SCS is synchronized with a synchrocyclotron to capture individual proton-beam-pulses (PBPs) at ∼504 frames/sec. The PBPs from synchrocyclotron trigger the HS-SCS to open its shutter for programmed exposure-time. Light emissions within 30×30×5cm3 plastic-scintillator (BC-408) were captured by a CCD-camera as individual images revealing dose-deposition in a 2D-plane with a resolution of 0.7mm for range and SOBP measurements and 1.67mm for profiles. The CCD response as well as signal to noise ratio (SNR) was characterized for varying exposure times, gains for different light intensities using a TV-Optoliner system. Software tools were developed to analyze ∼5000 images to extract different beam parameters. Quenching correction-factors were established by comparing scintillation Bragg-Peaks with water scanned ionization-chamber measurements. Quenching corrected Bragg-peaks were integrated to ascertain proton-beam range (PBR), width of Spared-Out-Bragg-Peak (MOD) and distal.

  7. A tilted fiber-optic plate coupled CCD detector for high resolution neutron imaging

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jongyul; Cho, Gyuseong [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of); Kim, Jongyul; Hwy, Limchang; Kim, Taejoo; Lee, Kyehong [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Lee, Seungwook [Pusan National Univ., Pusan (Korea, Republic of)

    2013-05-15

    One of these efforts is that a tilted scintillator geometry and lens coupled CCD detector for neutron imaging system were used to improve spatial resolution in one dimension. The increased spatial resolution in one dimension was applied to fuel cell study. However, a lens coupled CCD detector has lower sensitivity than a fiber-optic plate coupled CCD detector due to light loss. In this research, a tilted detector using fiber-optic plate coupled CCD detector was developed to improve resolution and sensitivity. In addition, a tilted detector can prevent an image sensor from direct radiation damage. Neutron imaging has been used for fuel cell study, lithium ion battery study, and many scientific applications. High quality neutron imaging is demanded for more detailed studies of applications, and spatial resolution should be considered to get high quality neutron imaging. Therefore, there were many efforts to improve spatial resolution.

  8. Measurement of scintillation decay curves by a single photon counting technique

    International Nuclear Information System (INIS)

    Noguchi, Tsutomu

    1978-01-01

    An improved apparatus suitable for the measurement of spectroscopic scintillation decay curves has been developed by combination of a single photon counting technique and a delayed coincidence method. The time resolution of the apparatus is improved up to 1.16 nsec (FWHM), which is obtained from the resolution function of the system for very weak Cherenkov light flashes. Systematic measurement of scintillation decay curves is made for liquid and crystal scintillators including PPO-toluene, PBD-xylene, PPO-POPOP-toluene, anthracene and stilbene. (auth.)

  9. A new approach to film dosimetry for high-energy photon beams using organic plastic scintillators

    International Nuclear Information System (INIS)

    Yeo, I.J.; Wang, C.-K.C.; Burch, S.E.

    1999-01-01

    Successful radiotherapy relies on accurate dose measurement. Traditional dosimeters such as ion chambers, TLDs and diodes have disadvantages such as relatively long measurement time and poor spatial resolution. These drawbacks become more serious problems for dynamic beams (i.e. with the use of dynamic wedges or even the intensity modulation technique). X-ray film, an integrating dosimeter, may not be associated with the above disadvantages and problems. However, there are several major issues regarding use of x-ray film for routine dosimetry, including the over-response of the film to low-energy photons, variations in the dose response curve (nonlinearity), lack of reproducibility due to variation in processing, etc. This paper addresses the first problem. That is, x-ray film over-responds to low-energy photons (energies below 400 keV), and thus generates unacceptably inaccurate dosimetric data compared with ion-chamber data. To overcome the over-response problem of x-ray film in a phantom, a scintillation method has been investigated. In this method, a film is sandwiched by two plastic scintillation screens to enhance the film response to upstream electrons, and therefore minimize the over-response caused by low-energy photons. The sandwiched system was tested with a 4 MV linac beam. The result shows that, depending on the uniformity of the scintillation screens, the depth-dose distribution obtained from the sandwich system can be made to agree well with that obtained from ion chambers. However, the required high degree of uniformity remains a challenge for the scintillation screen manufacturers. (author)

  10. Development of high-resolution x-ray CT system using parallel beam geometry

    Energy Technology Data Exchange (ETDEWEB)

    Yoneyama, Akio, E-mail: akio.yoneyama.bu@hitachi.com; Baba, Rika [Central Research Laboratory, Hitachi Ltd., Hatoyama, Saitama (Japan); Hyodo, Kazuyuki [Institute of Materials Science, High Energy Accelerator Research Organization, Tsukuba, Ibaraki (Japan); Takeda, Tohoru [School of Allied Health Sciences, Kitasato University, Sagamihara, Kanagawa (Japan); Nakano, Haruhisa; Maki, Koutaro [Department of Orthodontics, School of Dentistry Showa University, Ota-ku, Tokyo (Japan); Sumitani, Kazushi; Hirai, Yasuharu [Kyushu Synchrotron Light Research Center, Tosu, Saga (Japan)

    2016-01-28

    For fine three-dimensional observations of large biomedical and organic material samples, we developed a high-resolution X-ray CT system. The system consists of a sample positioner, a 5-μm scintillator, microscopy lenses, and a water-cooled sCMOS detector. Parallel beam geometry was adopted to attain a field of view of a few mm square. A fine three-dimensional image of birch branch was obtained using a 9-keV X-ray at BL16XU of SPring-8 in Japan. The spatial resolution estimated from the line profile of a sectional image was about 3 μm.

  11. Characterization of a high resolution and high sensitivity pre-clinical PET scanner with 3D event reconstruction

    CERN Document Server

    Rissi, M; Bolle, E; Dorholt, O; Hines, K E; Rohne, O; Skretting, A; Stapnes, S; Volgyes, D

    2012-01-01

    COMPET is a preclinical PET scanner aiming towards a high sensitivity, a high resolution and MRI compatibility by implementing a novel detector geometry. In this approach, long scintillating LYSO crystals are used to absorb the gamma-rays. To determine the point of interaction (P01) between gamma-ray and crystal, the light exiting the crystals on one of the long sides is collected with wavelength shifters (WLS) perpendicularly arranged to the crystals. This concept has two main advantages: (1) The parallax error is reduced to a minimum and is equal for the whole field of view (FOV). (2) The P01 and its energy deposit is known in all three dimension with a high resolution, allowing for the reconstruction of Compton scattered gamma-rays. Point (1) leads to a uniform point source resolution (PSR) distribution over the whole FOV, and also allows to place the detector close to the object being imaged. Both points (1) and (2) lead to an increased sensitivity and allow for both high resolution and sensitivity at the...

  12. A helium gas scintillator active target for photoreaction measurements

    Energy Technology Data Exchange (ETDEWEB)

    Al Jebali, Ramsey; Annand, John R.M.; Buchanan, Emma; Gardner, Simon; Hamilton, David J.; Livingston, Kenneth; McGeorge, John C.; MacGregor, Ian J.D.; MacRae, Roderick; Reiter, Andreas J.H.; Rosner, Guenther; Sokhan, Daria; Strandberg, Bruno [University of Glasgow, School of Physics and Astronomy, Glasgow, Scotland (United Kingdom); Adler, Jan-Olof; Fissum, Kevin; Schroeder, Bent [University of Lund, Department of Physics, Lund (Sweden); Akkurt, Iskender [Sueleyman Demirel University, Fen-Edebiyat Faculty, Isparta (Turkey); Brudvik, Jason; Hansen, Kurt; Isaksson, Lennart; Lundin, Magnus [MAX IV Laboratory, PO Box 118, Lund (Sweden); Middleton, Duncan G. [Universitaet Tuebingen, Kepler Centre for Astro and Particle Physics, Physikalisches Institut, Tuebingen (Germany); Sjoegren, Johan [University of Glasgow, School of Physics and Astronomy, Glasgow, Scotland (United Kingdom); MAX IV Laboratory, PO Box 118, Lund (Sweden)

    2015-10-15

    A multi-cell He gas scintillator active target, designed for the measurement of photoreaction cross sections, is described. The target has four main chambers, giving an overall thickness of 0.103 g/cm{sup 3} at an operating pressure of 2 MPa. Scintillations are read out by photomultiplier tubes and the addition of small amounts of N{sub 2} to the He, to shift the scintillation emission from UV to visible, is discussed. First results of measurements at the MAX IV Laboratory tagged-photon facility show that the target has a timing resolution of around 1 ns and can cope well with a high-flux photon beam. The determination of reaction cross sections from target yields relies on a Monte Carlo simulation, which considers scintillation light transport, photodisintegration processes in {sup 4}He, background photon interactions in target windows and interactions of the reaction-product particles in the gas and target container. The predictions of this simulation are compared to the measured target response. (orig.)

  13. Use and imaging performance of CMOS flat panel imager with LiF/ZnS(Ag) and Gadox scintillation screens for neutron radiography

    Science.gov (United States)

    Cha, B. K.; kim, J. Y.; Kim, T. J.; Sim, C.; Cho, G.; Lee, D. H.; Seo, C.-W.; Jeon, S.; Huh, Y.

    2011-01-01

    In digital neutron radiography system, a thermal neutron imaging detector based on neutron-sensitive scintillating screens with CMOS(complementary metal oxide semiconductor) flat panel imager is introduced for non-destructive testing (NDT) application. Recently, large area CMOS APS (active-pixel sensor) in conjunction with scintillation films has been widely used in many digital X-ray imaging applications. Instead of typical imaging detectors such as image plates, cooled-CCD cameras and amorphous silicon flat panel detectors in combination with scintillation screens, we tried to apply a scintillator-based CMOS APS to neutron imaging detection systems for high resolution neutron radiography. In this work, two major Gd2O2S:Tb and 6LiF/ZnS:Ag scintillation screens with various thickness were fabricated by a screen printing method. These neutron converter screens consist of a dispersion of Gd2O2S:Tb and 6LiF/ZnS:Ag scintillating particles in acrylic binder. These scintillating screens coupled-CMOS flat panel imager with 25x50mm2 active area and 48μm pixel pitch was used for neutron radiography. Thermal neutron flux with 6x106n/cm2/s was utilized at the NRF facility of HANARO in KAERI. The neutron imaging characterization of the used detector was investigated in terms of relative light output, linearity and spatial resolution in detail. The experimental results of scintillating screen-based CMOS flat panel detectors demonstrate possibility of high sensitive and high spatial resolution imaging in neutron radiography system.

  14. Scintillation Response of CaF2 to H and He over a Continuous Energy Range

    International Nuclear Information System (INIS)

    Zhang, Yanwen; Xiang, Xia; Weber, William J.

    2008-01-01

    Recent demands for new radiation detector materials with improved γ-ray detection performance at room temperature have prompted research efforts on both accelerated material discovery and efficient techniques that can be used to identify material properties relevant to detector performance. New material discovery has been limited due to the difficulties of large crystal growth to completely absorb γ-energies; whereas high-quality thin films or small crystals of candidate materials can be readily produced by various modern growth techniques. In this work, an ion-scintillator technique is demonstrated that can be applied to study scintillation properties of thin films and small crystals. The scintillation response of a benchmark scintillator, europium-doped calcium fluoride (CaF2:Eu), to energetic proton and helium ions is studied using the ion-scintillator approach based on a time of flight (TOF) telescope. Excellent energy resolution and fast response of the TOF telescope allow quantitative measurement of light yield, nonlinearity and energy resolution over an energy range from a few tens to a few thousands of keV

  15. Transparent Ceramic Scintillator Fabrication, Properties and Applications

    International Nuclear Information System (INIS)

    Cherepy, N.J.; Kuntz, J.D.; Roberts, J.J.; Hurst, T.A.; Drury, O.B.; Sanner, R.D.; Tillotson, T.M.; Payne, S.A.

    2008-01-01

    Transparent ceramics offer an alternative to single crystals for scintillator applications such as gamma ray spectroscopy and radiography. We have developed a versatile, scaleable fabrication method, using Flame Spray Pyrolysis (FSP) to produce feedstock which is readily converted into phase-pure transparent ceramics. We measure integral light yields in excess of 80,000 Ph/MeV with Cerium-doped Garnets, and excellent optical quality. Avalanche photodiode readout of Garnets provides resolution near 6%. For radiography applications, Lutetium Oxide offers a high performance metric and is formable by ceramics processing. Scatter in transparent ceramics due to secondary phases is the principal limitation to optical quality, and afterglow issues that affect the scintillation performance are presently being addressed

  16. Silicon photomultipliers for scintillating trackers

    Energy Technology Data Exchange (ETDEWEB)

    Rabaioli, S., E-mail: simone.rabaioli@gmail.com [Universita degli Studi dell' Insubria, Via Valleggio, 11 - 22100 Como (Italy); Berra, A.; Bolognini, D. [Universita degli Studi dell' Insubria, Via Valleggio, 11 - 22100 Como (Italy); INFN sezione di Milano Bicocca (Italy); Bonvicini, V. [INFN sezione di Trieste (Italy); Bosisio, L. [Universita degli Studi di Trieste and INFN sezione di Trieste (Italy); Ciano, S.; Iugovaz, D. [INFN sezione di Trieste (Italy); Lietti, D. [Universita degli Studi dell' Insubria, Via Valleggio, 11 - 22100 Como (Italy); INFN sezione di Milano Bicocca (Italy); Penzo, A. [INFN sezione di Trieste (Italy); Prest, M. [Universita degli Studi dell' Insubria, Via Valleggio, 11 - 22100 Como (Italy); INFN sezione di Milano Bicocca (Italy); Rashevskaya, I.; Reia, S. [INFN sezione di Trieste (Italy); Stoppani, L. [Universita degli Studi dell' Insubria, Via Valleggio, 11 - 22100 Como (Italy); Vallazza, E. [INFN sezione di Trieste (Italy)

    2012-12-11

    In recent years, silicon photomultipliers (SiPMs) have been proposed as a new kind of readout device for scintillating detectors in many experiments. A SiPM consists of a matrix of parallel-connected pixels, which are independent photon counters working in Geiger mode with very high gain ({approx}10{sup 6}). This contribution presents the use of an array of eight SiPMs (manufactured by FBK-irst) for the readout of a scintillating bar tracker (a small size prototype of the Electron Muon Ranger detector for the MICE experiment). The performances of the SiPMs in terms of signal to noise ratio, efficiency and time resolution will be compared to the ones of a multi-anode photomultiplier tube (MAPMT) connected to the same bars. Both the SiPMs and the MAPMT are interfaced to a VME system through a 64 channel MAROC ASIC.

  17. Silicon photomultipliers for scintillating trackers

    Science.gov (United States)

    Rabaioli, S.; Berra, A.; Bolognini, D.; Bonvicini, V.; Bosisio, L.; Ciano, S.; Iugovaz, D.; Lietti, D.; Penzo, A.; Prest, M.; Rashevskaya, I.; Reia, S.; Stoppani, L.; Vallazza, E.

    2012-12-01

    In recent years, silicon photomultipliers (SiPMs) have been proposed as a new kind of readout device for scintillating detectors in many experiments. A SiPM consists of a matrix of parallel-connected pixels, which are independent photon counters working in Geiger mode with very high gain (∼106). This contribution presents the use of an array of eight SiPMs (manufactured by FBK-irst) for the readout of a scintillating bar tracker (a small size prototype of the Electron Muon Ranger detector for the MICE experiment). The performances of the SiPMs in terms of signal to noise ratio, efficiency and time resolution will be compared to the ones of a multi-anode photomultiplier tube (MAPMT) connected to the same bars. Both the SiPMs and the MAPMT are interfaced to a VME system through a 64 channel MAROC ASIC.

  18. Simulation of light collection in calcium tungstate scintillation detectors

    Directory of Open Access Journals (Sweden)

    F. A. Danevich

    2015-12-01

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

  19. Decay Time Measurement for Different Energy Depositions of Plastic Scintillator Fabricated by High Temperature Polymerization Reaction

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Cheol Ho; Son, Jaebum; Lee, Sangmin; Kim, Tae Hoon; Kim, Yong-Kyun [Hanyang University, Seoul (Korea, Republic of)

    2016-10-15

    Plastic scintillators are based on organic fluorite. They have many advantages such as fast rise and decay time, high optical transmission, ease of manufacturing, low cost, and large available size. For these reasons they are widely used for particle identification. Also, protection of people against a variety of threats (such as nuclear, radiological, and explosive) represents a true challenge along with the continuing development of science and technology. The plastic scintillator is widely used in various devise, which serves for nuclear, photonics, quantum, and high-energy physics. The plastic scintillator is probably the most widely used organic detector, and polystyrene is one of the most widely used materials in the making of the plastic scintillator detector. Thus, a styrene monomer as a solvent was used to fabricate the plastic scintillator by using high temperature polymerization reaction, and then the emission wavelength and the decay times for different energy depositions were measured by using the fabricated plastic scintillator. A plastic scintillator was fabricated to measure decay time for different energy depositions using the high temperature polymerization. Emission wavelength was measured of 426.05 nm to confirm a scintillator property using the spectrophotometer. Four gamma-ray sources (Cs-137, Co-60, Na-22, and Ba-133) were used to evaluate effect for decay time of different energy depositions. The average decay time of the fabricated plastic scintillator was measured to approximately 4.72 ns slightly higher more than commercial plastic scintillator. In future, light output and linearity will be measured to evaluate other property compared with the commercial scintillator.

  20. Decay Time Measurement for Different Energy Depositions of Plastic Scintillator Fabricated by High Temperature Polymerization Reaction

    International Nuclear Information System (INIS)

    Lee, Cheol Ho; Son, Jaebum; Lee, Sangmin; Kim, Tae Hoon; Kim, Yong-Kyun

    2016-01-01

    Plastic scintillators are based on organic fluorite. They have many advantages such as fast rise and decay time, high optical transmission, ease of manufacturing, low cost, and large available size. For these reasons they are widely used for particle identification. Also, protection of people against a variety of threats (such as nuclear, radiological, and explosive) represents a true challenge along with the continuing development of science and technology. The plastic scintillator is widely used in various devise, which serves for nuclear, photonics, quantum, and high-energy physics. The plastic scintillator is probably the most widely used organic detector, and polystyrene is one of the most widely used materials in the making of the plastic scintillator detector. Thus, a styrene monomer as a solvent was used to fabricate the plastic scintillator by using high temperature polymerization reaction, and then the emission wavelength and the decay times for different energy depositions were measured by using the fabricated plastic scintillator. A plastic scintillator was fabricated to measure decay time for different energy depositions using the high temperature polymerization. Emission wavelength was measured of 426.05 nm to confirm a scintillator property using the spectrophotometer. Four gamma-ray sources (Cs-137, Co-60, Na-22, and Ba-133) were used to evaluate effect for decay time of different energy depositions. The average decay time of the fabricated plastic scintillator was measured to approximately 4.72 ns slightly higher more than commercial plastic scintillator. In future, light output and linearity will be measured to evaluate other property compared with the commercial scintillator

  1. Cerenkov counting and Cerenkov-scintillation counting with high refractive index organic liquids using a liquid scintillation counter

    Energy Technology Data Exchange (ETDEWEB)

    Wiebe, L I; Helus, F; Maier-Borst, W [Deutsches Krebsforschungszentrum, Heidelberg (Germany, F.R.). Inst. fuer Nuklearmedizin

    1978-06-01

    /sup 18/F and /sup 14/C radioactivity was measured in methyl salicylate (MS), a high refractive index hybrid Cherenkov-scintillation generating medium, using a liquid scintillation counter. At concentrations of up to 21.4%, in MS, dimethyl sulfoxide (DMSO) quenched /sup 14/C fluorescence, and with a 10-fold excess of DMSO over MS, /sup 18/F count rates were reduced below that for DMSO alone, probably as a result of concentration-independent self-quenching due to 'dark-complex' formation. DMSO in lower concentrations did not reduce the counting efficiency of /sup 18/F in MS. Nitrobenzene was a concentration-dependent quencher for both /sup 14/C and /sup 18/F in MS. Chlorobenzene (CB) and DMSO were both found to be weak Cherenkov generators with /sup 18/F. Counting efficiencies for /sup 18/F in MS, CB, and DMSO were 50.3, 7.8 and 4.3% respectively in the coincidence counting mode, and 58.1, 13.0 and 6.8% in the singles mode. /sup 14/C efficiencies were 14.4 and 22.3% for coincidence and singles respectively, and 15.3 and 42.0% using a modern counter designed for coincidence and single photon counting. The high /sup 14/C and /sup 18/F counting efficiency in MS are discussed with respect to excitation mechanism, on the basis of quench and channels ratios changes observed. It is proposed that MS functions as an efficient Cherenkov-scintillation generator for high-energy beta emitters such as /sup 18/F, and as a low-efficiency scintillator for weak beta emitting radionuclides such as /sup 14/C.

  2. Measurements of the electron dose distribution near inhomogeneities using a plastic scintillation detector

    International Nuclear Information System (INIS)

    Wells, C.M.M.; Mackie, T.R.; Podgorsak, M.B.; Holmes, M.A.; Papanikolaou, N.; Reckwerdt, P.J.; Cygler, J.; Rogers, D.W.O.; Bielajew, A.F.; Schmidt, D.G.

    1994-01-01

    Accurate measurement of the electron dose distribution near an inhomogeneity is difficult with traditional dosimeters which themselves perturb the electron field. The authors tested the performance of a new high resolution, water-equivalent plastic scintillation detector which has ideal properties for this application. A plastic scintillation detector with a 1 mm diameter, 3 mm long cylindrical sensitive volume was used to measure the dose distributions behind standard benchmark inhomogeneities in water phantoms. The plastic scintillator material is more water equivalent than polystyrene in terms of its mass collision stopping power and mass scattering power. Measurements were performed for beams of electrons having initial energies of 6 and 18 MeV at depths from 0.2-4.2 cm behind the inhomogeneities. The detector reveals hot and cold spots behind heterogeneities at resolutions equivalent to typical film digitizer spot sizes. Plots of the dose distributions behind air, aluminum, lead, and formulations for cortical and inner bone-equivalent materials are presented. The plastic scintillation detector is suited for measuring the electron dose distribution near an inhomogeneity. 14 refs., 9 figs

  3. Scintillation and ionization yields produced by α-particles in high-density gaseous xenon

    International Nuclear Information System (INIS)

    Kusano, H.; Ishikawa, T.; Lopes, J.A.M.; Miyajima, M.; Shibamura, E.; Hasebe, N.

    2012-01-01

    The average numbers of scintillation photons and liberated electrons produced by 5.49-MeV α-particles were measured in high-density gaseous xenon. The density range is 0.12–1.32 g/cm 3 for scintillation measurements at zero electric field, and 0.12–1.03 g/cm 3 for the scintillation and ionization measurements under various electric fields. The density dependence of scintillation yield at zero electric field was observed. The W s -value, which is defined as the average energy expended per photon, increases with density and becomes almost constant in the density range above 1.0 g/cm 3 . Anti-correlations between average numbers of scintillation photons and liberated electrons were found to vary with density. It was also found that the total number of scintillation photons and liberated electrons decreases with increasing density. Several possible reasons for the variation in scintillation and ionization yields with density are discussed.

  4. Memory effect, resolution, and efficiency measurements of an Al2O3 coated plastic scintillator used for radioxenon detection

    Science.gov (United States)

    Bläckberg, L.; Fritioff, T.; Mårtensson, L.; Nielsen, F.; Ringbom, A.; Sjöstrand, H.; Klintenberg, M.

    2013-06-01

    A cylindrical plastic scintillator cell, used for radioxenon monitoring within the verification regime of the Comprehensive Nuclear-Test-Ban Treaty, has been coated with 425 nm Al2O3 using low temperature Atomic Layer Deposition, and its performance has been evaluated. The motivation is to reduce the memory effect caused by radioxenon diffusing into the plastic scintillator material during measurements, resulting in an elevated detection limit. Measurements with the coated detector show both energy resolution and efficiency comparable to uncoated detectors, and a memory effect reduction of a factor of 1000. Provided that the quality of the detector is maintained for a longer period of time, Al2O3 coatings are believed to be a viable solution to the memory effect problem in question.

  5. Memory effect, resolution, and efficiency measurements of an Al2O3 coated plastic scintillator used for radioxenon detection

    International Nuclear Information System (INIS)

    Bläckberg, L.; Fritioff, T.; Mårtensson, L.; Nielsen, F.; Ringbom, A.; Sjöstrand, H.; Klintenberg, M.

    2013-01-01

    A cylindrical plastic scintillator cell, used for radioxenon monitoring within the verification regime of the Comprehensive Nuclear-Test-Ban Treaty, has been coated with 425 nm Al 2 O 3 using low temperature Atomic Layer Deposition, and its performance has been evaluated. The motivation is to reduce the memory effect caused by radioxenon diffusing into the plastic scintillator material during measurements, resulting in an elevated detection limit. Measurements with the coated detector show both energy resolution and efficiency comparable to uncoated detectors, and a memory effect reduction of a factor of 1000. Provided that the quality of the detector is maintained for a longer period of time, Al 2 O 3 coatings are believed to be a viable solution to the memory effect problem in question

  6. Simulation of scintillating fiber gamma ray detectors for medical imaging

    International Nuclear Information System (INIS)

    Chaney, R.C.; Fenyves, E.J.; Antich, P.P.

    1990-01-01

    This paper reports on plastic scintillating fibers which have been shown to be effective for high spatial and time resolution of gamma rays. They may be expected to significantly improve the resolution of current medical imaging systems such as PET and SPECT. Monte Carlo simulation of imaging systems using these detectors, provides a means to optimize their performance in this application, as well as demonstrate their resolution and efficiency. Monte Carlo results are presented for PET and SPECT systems constructed using these detectors

  7. High resolution time-of-flight (TOF) detector for particle identification

    Energy Technology Data Exchange (ETDEWEB)

    Boehm, Merlin; Lehmann, Albert; Pfaffinger, Markus; Uhlig, Fred [Physikalisches Institut, Universitaet Erlangen-Nuernberg (Germany); Collaboration: PANDA-Collaboration

    2016-07-01

    Several prototype tests were performed with the PANDA DIRC detectors at the CERN T9 beam line. A mixed hadron beam with pions, kaons and protons was used at momenta from 2 to 10 GeV/c. For these tests a good particle identification was mandatory. We report about a high resolution TOF detector built especially for this purpose. It consists of two stations each consisting of a Cherenkov radiator read out by a Microchannel-Plate Photomultiplier (MCP-PMT) and a Scintillating Tile (SciTil) counter read out by silicon photomultipliers (SiPMs). With a flight path of 29 m a pion/kaon separation up to 5 GeV/c and a pion/proton separation up to 10 GeV/c was obtained. From the TOF resolutions of different counter combinations the time resolution (sigma) of the individual MCP-PMTs and SciTils was determined. The best counter reached a time resolution of 50 ps.

  8. New heavy scintillating materials for precise heterogeneous EM-calorimeters

    International Nuclear Information System (INIS)

    Britvich, G.I.; Britvich, I.G.; Vasil'chenko, V.G.; Lishin, V.A.; Obraztsov, V.F.; Polyakov, V.A.; Solovjev, A.S.; Ryzhikov, V.D.

    2001-01-01

    This investigation shows some optical and scintillation properties of new scintillating media, based on heavy composite materials and an inorganic crystal CsI:Br, intended for the creation of precise heterogeneous EM-calorimeters with the energy resolution σ/E congruent with 4-5% E-radical. The possibility to use cheap heavy scintillating plates based on optical ceramics as active media in heterogeneous EM-calorimeters is considered

  9. Performance of the first prototype of the CALICE scintillator strip electromagnetic calorimeter

    CERN Document Server

    Francis, K.; Schlereth, J.; Smith, J.; Xia, L.; Baldolemar, E.; Li, J.; Park, S.T.; Sosebee, M.; White, A.P.; Yu, J.; Eigen, G.; Mikami, Y.; Watson, N.K.; Thomson, M.A.; Ward, D.R.; Benchekroun, D.; Hoummada, A.; Khoulaki, Y.; Apostolakis, J.; Dotti, A.; Folger, G.; Ivantchenko, V.; Ribon, A.; Uzhinskiy, V.; Carloganu, C.; Gay, P.; Manen, S.; Royer, L.; Tytgat, M.; Zaganidis, N.; Blazey, G.C.; Dyshkant, A.; Lima, J.G.R.; Zutshi, V.; Hostachy, J. -Y.; Morin, L.; Cornett, U.; David, D.; Ebrahimi, A.; Falley, G.; Gadow, K.; Goettlicher, P.; Guenter, C.; Hartbrich, O.; Hermberg, B.; Karstensen, S.; Krivan, F.; Krueger, K.; Lutz, B.; Morozov, S.; Morgunov, V.; Neubueser, C.; Reinecke, M.; Sefkow, F.; Smirnov, P.; Terwort, M.; Garutti, E.; Laurien, S.; Lu, S.; Marchesini, I.; Matysek, M.; Ramilli, M.; Briggl, K.; Eckert, P.; Harion, T.; Schultz-Coulon, H. -Ch.; Shen, W.; Stamen, R.; Bilki, B.; Norbeck, E.; Northacker, D.; Onel, Y.; Wilson, G.W.; Kawagoe, K.; Sudo, Y.; Yoshioka, T.; Dauncey, P.D.; Wing, M.; Salvatore, F.; Cortina Gil, E.; Mannai, S.; Baulieu, G.; Calabria, P.; Caponetto, L.; Combaret, C.; Della Negra, R.; Grenier, G.; Han, R.; Ianigro, J-C.; Kieffer, R.; Laktineh, I.; Lumb, N.; Mathez, H.; Mirabito, L.; Petrukhin, A.; Steen, A.; Tromeur, W.; Vander donckt, M.; Zoccarato, Y.; Calvo Alamillo, E.; Fouz, M.-C.; Puerta-Pelayo, J.; Corriveau, F.; Bobchenko, B.; Chadeeva, M.; Danilov, M.; Epifantsev, A.; Markin, O.; Mizuk, R.; Novikov, E.; Popov, V.; Rusinov, V.; Tarkovsky, E.; Besson, D.; Buzhan, P.; Ilyin, A.; Kantserov, V.; Kaplin, V.; Karakash, A.; Popova, E.; Tikhomirov, V.; Kiesling, C.; Seidel, K.; Simon, F.; Soldner, C.; Weuste, L.; Amjad, M.S.; Bonis, J.; Callier, S.; Conforti di Lorenzo, S.; Cornebise, P.; Doublet, Ph.; Dulucq, F.; Fleury, J.; Frisson, T.; van der Kolk, N.; Li, H.; Martin-Chassard, G.; Richard, F.; de la Taille, Ch.; Poeschl, R.; Raux, L.; Rouene, J.; Seguin-Moreau, N.; Anduze, M.; Balagura, V.; Boudry, V.; Brient, J-C.; Cornat, R.; Frotin, M.; Gastaldi, F.; Guliyev, E.; Haddad, Y.; Magniette, F.; Musat, G.; Ruan, M.; Tran, T.H.; Videau, H.; Bulanek, B.; Zacek, J.; Cvach, J.; Gallus, P.; Havranek, M.; Janata, M.; Kvasnicka, J.; Lednicky, D.; Marcisovsky, M.; Polak, I.; Popule, J.; Tomasek, L.; Tomasek, M.; Ruzicka, P.; Sicho, P.; Smolik, J.; Vrba, V.; Zalesak, J.; Belhorma, B.; Ghazlane, H.; Kotera, K.; Ono, H.; Takeshita, T.; Uozumi, S.; Jeans, D.; Chang, S.; Khan, A.; Kim, D.H.; Kong, D.J.; Oh, Y.D.; Goetze, M.; Sauer, J.; Weber, S.; Zeitnitz, C.

    2014-11-01

    A first prototype of a scintillator strip-based electromagnetic calorimeter was built, consisting of 26 layers of tungsten absorber plates interleaved with planes of 45x10x3 mm3 plastic scintillator strips. Data were collected using a positron test beam at DESY with momenta between 1 and 6 GeV/c. The prototype's performance is presented in terms of the linearity and resolution of the energy measurement. These results represent an important milestone in the development of highly granular calorimeters using scintillator strip technology. This technology is being developed for a future linear collider experiment, aiming at the precise measurement of jet energies using particle flow techniques.

  10. Variable sampling-time technique for improving count rate performance of scintillation detectors

    International Nuclear Information System (INIS)

    Tanaka, E.; Nohara, N.; Murayama, H.

    1979-01-01

    A new technique is presented to improve the count rate capability of a scintillation spectrometer or a position sensitive detector with minimum loss of resolution. The technique is based on the combination of pulse shortening and selective integration in which the integration period is not fixed but shortened by the arrival of the following pulse. Theoretical analysis of the degradation of the statiscal component of resolution is made for the proposed system with delay line pulse shortening, and the factor of resolution loss is formulated as a function of the input pulse rate. A new method is also presented for determining the statistical component of resolution separately from the non-statistical system resolution. Preliminary experiments with a NaI(Tl) detector have been carried out, the results of which are consistent with the theoretical prediction. However, due to the non-exponential scintillation decay of the NaI(Tl) crystal, a simple delay line clipping is not satisfactory, and an RC high-pass filter has been added, which results in further degradation of the statistical resolution. (Auth.)

  11. Effects of detector–source distance and detector bias voltage variations on time resolution of general purpose plastic scintillation detectors

    International Nuclear Information System (INIS)

    Ermis, E.E.; Celiktas, C.

    2012-01-01

    Effects of source-detector distance and the detector bias voltage variations on time resolution of a general purpose plastic scintillation detector such as BC400 were investigated. 133 Ba and 207 Bi calibration sources with and without collimator were used in the present work. Optimum source-detector distance and bias voltage values were determined for the best time resolution by using leading edge timing method. Effect of the collimator usage on time resolution was also investigated. - Highlights: ► Effect of the source-detector distance on time spectra was investigated. ► Effect of the detector bias voltage variations on time spectra was examined. ► Optimum detector–source distance was determined for the best time resolution. ► Optimum detector bias voltage was determined for the best time resolution. ► 133 Ba and 207 Bi radioisotopes were used.

  12. Scintillator plate calorimetry

    International Nuclear Information System (INIS)

    Price, L.E.

    1990-01-01

    Calorimetry using scintillator plates or tiles alternated with sheets of (usually heavy) passive absorber has been proven over multiple generations of collider detectors. Recent detectors including UA1, CDF, and ZEUS have shown good results from such calorimeters. The advantages offered by scintillator calorimetry for the SSC environment, in particular, are speed (<10 nsec), excellent energy resolution, low noise, and ease of achieving compensation and hence linearity. On the negative side of the ledger can be placed the historical sensitivity of plastic scintillators to radiation damage, the possibility of nonuniform response because of light attenuation, and the presence of cracks for light collection via wavelength shifting plastic (traditionally in sheet form). This approach to calorimetry is being investigated for SSC use by a collaboration of Ames Laboratory/Iowa State University, Argonne National Laboratory, Bicron Corporation, Florida State University, Louisiana State University, University of Mississippi, Oak Ridge National Laboratory, Virginia Polytechnic Institute and State University, Westinghouse Electric Corporation, and University of Wisconsin

  13. Measurement of the plastic scintillator response to heavy ions, between 0 to 30 MeV/N

    International Nuclear Information System (INIS)

    Dorion, I.

    1984-01-01

    The light produced in a plastic scintillator depends on particle nature and energy. Theoretical models predict a linear behavior of the light output response for high energy heavy ions. An experimental set-up was realised in order to perform the integral and, in some case, the differential measurement of the light yield in a plastic scintillator (NE102) stopping 6 Li, 12 C, 16 O, 20 Ne, 40 Ar ions given by SARA, with particle incident energy from 3 to 30 MeV per nucleon. The plastic resolution was also measured. The data analysis leads to experimental results which are in good agreement with the predictions. Taking into account resolution value, the use of plastic scintillator in detection system allows in some case, particle identification [fr

  14. X-ray radiation detectors of 'scintillator-photoreceiving device type' for industrial digital radiography with improved spatial resolution

    International Nuclear Information System (INIS)

    Ryzhykov, V.D.; Lysetska, O.K.; Opolonin, O.D.; Kozin, D.N.

    2003-01-01

    Main types of photo receivers used in X-ray digital radiography systems are luminescent screens that transfer the optical image onto charge collection instruments, which require cooling, and semiconductor silicon detectors, which limit the contrast sensitivity. We have developed and produced X-ray radiation detectors of 'scintillator-photoreceiving device' (S-PRD) type, which are integrally located on the inverse side of the photodiode (PD). The receiving-converting circuit (RCC) is designed for data conversion into digital form and their input into PC. Software is provided for RCC control and image visualization. Main advantages of these detectors are high industrial resolution (3-5 line pairs per mm), detecting activity up to 20 μm, controlled sensitivity, low weight and small size, imaging low (0.1-0.3 mrad) object dose in real time. In this work, main characteristics of 32-, 64- and 1024-channel detectors of S-PRD type were studied and compared for X-ray sensitivity with S-PD detectors. Images of the tested objects have been obtained. Recommendations are given on the use of different scintillation materials, depending upon the purpose of a digital radiographic system. The detectors operate in a broad energy range of ionizing radiation, hence the size of the controlled object is not limited. The system is sufficiently powerful to ensure frontal (through two walls) observation of pipelines with wall thickness up to 10 cm

  15. Capillary detectors for high resolution tracking

    CERN Document Server

    Annis, P

    1997-01-01

    We present a new tracking device based on glass capillary bundles or layers filled with highly purified liquid scintillator and read out at one end by means of image intensifiers and CCD devices. A large-volume prototype consisting of 5 × 105 capillaries with a diameter of 20 μm and a length of 180 cm and read out by a megapixel CCD has been tested with muon and neutrino beams at CERN. With this prototype a two track resolution of 33 μm was achieved with passing through muons. Images of neutrino interactions in a capillary bundle have also been acquired and analysed. Read-out chains based on Electron Bombarded CCD (EBCCD) and image pipeline devices are also investigated. Preliminary results obtained with a capillary bundle read out by an EBCCD are presented.

  16. Practical use of a plastic scintillator for quality assurance of electron beam therapy.

    Science.gov (United States)

    Yogo, Katsunori; Tatsuno, Yuya; Tsuneda, Masato; Aono, Yuki; Mochizuki, Daiki; Fujisawa, Yoshiki; Matsushita, Akihiro; Ishigami, Minoru; Ishiyama, Hiromichi; Hayakawa, Kazushige

    2017-06-07

    Quality assurance (QA) of clinical electron beams is essential for performing accurate and safe radiation therapy. However, with advances in radiation therapy, QA has become increasingly labor-intensive and time-consuming. In this paper, we propose a tissue-equivalent plastic scintillator for quick and easy QA of clinical electron beams. The proposed tool comprises a plastic scintillator plate and a charge-coupled device camera that enable the scintillation light by electron beams to be recorded with high sensitivity and high spatial resolution. Further, the Cerenkov image is directly subtracted from the scintillation image to discriminate Cerenkov emissions and accurately measure the dose profiles of electron beams with high spatial resolution. Compared with conventional methods, discrepancies in the depth profile improved from 7% to 2% in the buildup region via subtractive corrections. Further, the output brightness showed good linearity with dose, good reproducibility (deviations below 1%), and dose rate independence (within 0.5%). The depth of 50% dose measured with the tool, an index of electron beam quality, was within  ±0.5 mm of that obtained with an ionization chamber. Lateral brightness profiles agreed with the lateral dose profiles to within 4% and no significant improvement was obtained using Cerenkov corrections. Field size agreed to within 0.5 mm with those obtained with ionization chamber. For clinical QA of electron boost treatment, a disk scintillator that mimics the shape of a patient's breast is applied. The brightness distribution and dose, calculated using a treatment planning system, was generally acceptable for clinical use, except in limited zones. Overall, the proposed plastic scintillator plate tool efficiently performs QA for electron beam therapy and enables simultaneous verification of output constancy, beam quality, depth, and lateral dose profiles during monthly QAs at lower doses of irradiation (small monitor units, MUs).

  17. Characteristics of Un doped and Europium-doped SrI2 Scintillator Detectors

    International Nuclear Information System (INIS)

    Sturm, Benjamin; Cherepy, Nerine; Drury, Owen; Thelin, P.; Fisher, S.E.; O'Neal, S.P.; Payne, Stephen A.; Burger, Arnold; Boatner, Lynn A.; Ramey, Joanne Oxendine; Shah, Kanai; Hawrami, Rastgo

    2012-01-01

    High energy resolution gamma-ray detectors that can be formed into relatively large sizes while operating at room temperature offer many advantages for national security applications. We are working toward that goal through the development of SrI 2 (Eu) scintillator detectors, which routinely provide ;10 cm 3 . In this study, we have tested pure, undoped SrI 2 to gain a better understanding of the scintillation properties and spectroscopic performance achievable without activation. An undoped crystal grown from 99.999% pure SrI 2 pellets was tested for its spectroscopic performance, its light yield, and uniformity of scintillation light collection as a function of gamma-ray interaction position relative to the crystal growth direction. Undoped SrI 2 was found to provide energy resolution of 5.3% at 662 keV, and the light collection nonuniformity varied by only 0.72% over the length of the crystal. Measurements of both a 3% Eu-doped and the undoped SrI 2 crystal were carried out in the SLYNCI facility and indicate differences in their light yield non-proportionality. The surprisingly good scintillation properties of the pure SrI 2 crystal suggests that with high-purity feedstock, further reduction of the Eu concentration can be made to grow larger crystals while not adversely impacting the spectroscopic performance.

  18. Intercalibration of the ZEUS high resolution and backing calorimeters

    International Nuclear Information System (INIS)

    Abramowicz, H.; Czyrkowski, H.; Derlicki, A.; Krzyzanowski, M.; Kudla, I.; Kusmierz, W.; Nowak, R.J.; Pawlak, J.M.; Rajca, A.; Stopczynski, A.; Walczak, R.; Zarnecki, A.F.; Kowalski, T.Z.

    1991-07-01

    We have studied the combined performance of two calorimeters, the high resolution uranium-scintillator prototype of the ZEUS forward calorimeter (FCAL), followed by a prototype of the coarser ZEUS backing calorimeter (BAC), made out of thick iron plates interleaved with planes of aluminium proportional chambers. The test results, obtained in an exposure of the calorimeter system to a hadron test beam at the CERN-SPS, show that the backing calorimeter does fulfil its role of recognizing the energy leaking out of the FCAL calorimeter. The measurement of this energy is feasible, if an appropriate calibration of the BAC calorimeter is performed. (orig.)

  19. Intercalibration of the ZEUS high resolution and backing calorimeters

    International Nuclear Information System (INIS)

    Abramowicz, H.; Czyrkowski, H.; Derlicki, A.; Krzyzanowski, M.; Kudla, I.; Kusmierz, W.; Nowak, R.J.; Pawlak, J.M.; Rajca, A.; Stopczynski, A.; Walczak, R.; Zarnecki, A.F.; Kowalski, T.Z.

    1992-01-01

    We have studied the combined performance of two calorimeters, the high resolution uranium-scintillator prototype of the ZEUS forward calorimeter (FCAL), followed by a prototype of the coarser ZEUS backing calorimeter (BAC), made out of thick iron plates interleaved with planes of aluminium proportional chambers. The test results, obtained in an exposure of the calorimeter system to a hadron test beam at the CERN SPS, show that the backing calorimeter does fulfil its role of recognizing the energy leaking out of the FCAL calorimeter. The measurement of this energy is feasible, if an appropriate calibration of the BAC calorimeter is performed. (orig.)

  20. Test of a Fiber Optic-Based LYSO Scintillator Dosimeter in a 60Co Irradiation Chamber

    International Nuclear Information System (INIS)

    Kim, Tae Hyoung; Kim, Jae Kyung; Park, Jae Woo

    2010-01-01

    Due to its excellent remote measurability and high spatial resolution, the fiber optic-based radiation dosimeter has been extensively explored for its usability in medical applications by several researchers. In the previous work, we reported the result of our investigation on feasibility of a photon dosimeter constructed with a BGO(Bi 4 Ge 3 O 12 ) or GSO(Gd 2 SiO 5 ) scintillator piece coupled to a plastic optical fiber. The plastic optical fiber had a diameter of 3mm and the scintillator piece was in a cylindrical form with 5mm diameter. The size of the scitillator piece as well as the fiber should be as small as possible for higher spatial resolution, and the radiation hardness should be high enough for stable operation in strong radiation fields. Recently, LYSO(Cerium-doped Lutetium Yttrium Orthosilicate) scintillators, which have much higher light yield and radiation hardness than BGO and GSO, have been commercially available. This paper reports the result of our investigation on dosimetric characteristics of a fiber optic-based dosimeter employing a smaller LYSO scintillator piece with 2mm diameter coupled to a silica optical fiber with 1mm core diameter

  1. Scintillation Particle Detectors Based on Plastic Optical Fibres and Microfluidics

    CERN Document Server

    Mapelli, Alessandro; Renaud, Philippe

    2011-01-01

    This thesis presents the design, development, and experimental validation of two types of scintillation particle detectors with high spatial resolution. The first one is based on the well established scintillating fibre technology. It will complement the ATLAS (A Toroidal Large ApparatuS) detector at the CERN Large Hadron Collider (LHC). The second detector consists in a microfabricated device used to demonstrate the principle of operation of a novel type of scintillation detector based on microfluidics. The first part of the thesis presents the work performed on a scintillating fibre tracking system for the ATLAS experiment. It will measure the trajectory of protons elastically scattered at very small angles to determine the absolute luminosity of the CERN LHC collider at the ATLAS interaction point. The luminosity of an accelerator characterizes its performance. It is a process-independent parameter that is completely determined by the properties of the colliding beams and it relates the cross section of a ...

  2. High-Z organic-scintillation solution

    International Nuclear Information System (INIS)

    Berlman, I.B.; Fluornoy, J.M.; Ashford, C.B.; Lyons, P.B.

    1983-01-01

    In the present experiment, an attempt is made to raise the average Z of a scintillation solution with as little attendant quenching as possible. Since high-Z atoms quench by means of a close encounter, such encounters are minimized by the use of alkyl groups substituted on the solvent, solute, and heavy atoms. The aromatic compound 1,2,4-trimethylbenzene (pseudocumene) is used as the solvent; 4,4''-di(5-tridecyl)-p-terphenyl (SC-180) as the solute; and tetrabutyltin as the high-Z material. To establish the validity of our ideas, various experiments have been performed with less protected solvents, and heavy atoms. These include benzene, toluene, p-terphenyl, bromobutane, and bromobenzene

  3. Perfomance of a compensating lead-scintillator hadronic calorimeter

    Science.gov (United States)

    Bernardi, E.; Drews, G.; Garcia, M. A.; Klanner, R.; Kötz, U.; Levman, G.; Lomperski, M.; Lüke, D.; Ros, E.; Selonke, F.; Tiecke, H.; Tsirou, M.; Vogel, W.

    1987-12-01

    We have built a sandwich calorimeter consisting of 10 mm thick lead plates and 2.5 mm thick scintillator sheets. The thickness ratio between lead and scintillator was optimized to achieve a good energy resolution for hadrons. We have exposed this calorimeter to electrons, hadrons and muons in the energy range between 3 and 75 GeV, obtaining an average energy resolution of {23%}/{E} for electrons and {44%}/{E} for hadrons. For energies above 10 GeV and after leakage corrections, the ratio of electron response to hardron response is 1.05.

  4. High resolution X-ray detector for synchrotron-based microtomography

    CERN Document Server

    Stampanoni, M; Wyss, P; Abela, R; Patterson, B; Hunt, S; Vermeulen, D; Rueegsegger, P

    2002-01-01

    Synchrotron-based microtomographic devices are powerful, non-destructive, high-resolution research tools. Highly brilliant and coherent X-rays extend the traditional absorption imaging techniques and enable edge-enhanced and phase-sensitive measurements. At the Materials Science Beamline MS of the Swiss Light Source (SLS), the X-ray microtomographic device is now operative. A high performance detector based on a scintillating screen optically coupled to a CCD camera has been developed and tested. Different configurations are available, covering a field of view ranging from 715x715 mu m sup 2 to 7.15x7.15 mm sup 2 with magnifications from 4x to 40x. With the highest magnification 480 lp/mm had been achieved at 10% modulation transfer function which corresponds to a spatial resolution of 1.04 mu m. A low-noise fast-readout CCD camera transfers 2048x2048 pixels within 100-250 ms at a dynamic range of 12-14 bit to the file server. A user-friendly graphical interface gives access to the main parameters needed for ...

  5. Scintillating bolometers: A promising tool for rare decays search

    Energy Technology Data Exchange (ETDEWEB)

    Pattavina, L., E-mail: luca.pattavina@mib.infn.it

    2013-12-21

    The idea of using a scintillating bolometer was first suggested for solar neutrino experiments in 1989. After many years of developments, now we are able to exploit this experimental technique, based on the calorimetric approach with cryogenic particle detectors, to investigate rare events such as Neutrinoless Double Beta Decay and interaction of Dark Matter candidates. The possibility to have high resolution detectors in which a very large part of the natural background can be discriminated with respect to the weak expected signal is very appealing. The goal to distinguish the different types of interactions in the detector can be achieved by means of scintillating bolometer. The simultaneous read-out of the heat and scintillation signals made with two independent bolometers enable this precious feature leading to possible background free experiment. In the frame of the LUCIFER project we report on how exploiting this technique to investigate Double Beta Decay for different isotope candidates. Moreover we demonstrate how scintillating bolometers are suited for investigating other rare events such as α decays of long living isotopes of lead and bismuth.

  6. New advanced in alpha spectrometry by liquid scintillation methods

    International Nuclear Information System (INIS)

    McDowell, W.J.; Case, G.N.

    1979-01-01

    Although the ability to count alpha particles by liquid scintillation methods has been long recognized, limited use has been made of the method because of problems of high background and alpha energy identification. In recent years some new developments in methods of introducing the alpha-emitting nuclide to the scintillator, in detector construction, and in electronics for processing the energy analog and time analog signals from the detector have allowed significant alleviation of the problems of alpha spectrometry by liquid scintillation. Energy resolutions of 200 to 300 keV full peak width at half maximum and background counts of 99% of all beta plus gamma interference is now possible. Alpha liquid scintillation spectrometry is now suitable for a wide range of applications, from the accurate quantitative determination of relatively large amounts of known nuclides in laboratory-generated samples to the detection and identification of very small, subpicocurie amounts of alpha emitters in environmental-type samples. Suitable nuclide separation procedures, sample preparation methods, and instrument configurations are available for a variety of analyses

  7. Super-resolution processing for pulsed neutron imaging system using a high-speed camera

    International Nuclear Information System (INIS)

    Ishizuka, Ken; Kai, Tetsuya; Shinohara, Takenao; Segawa, Mariko; Mochiki, Koichi

    2015-01-01

    Super-resolution and center-of-gravity processing improve the resolution of neutron-transmitted images. These processing methods calculate the center-of-gravity pixel or sub-pixel of the neutron point converted into light by a scintillator. The conventional neutron-transmitted image is acquired using a high-speed camera by integrating many frames when a transmitted image with one frame is not provided. It succeeds in acquiring the transmitted image and calculating a spectrum by integrating frames of the same energy. However, because a high frame rate is required for neutron resonance absorption imaging, the number of pixels of the transmitted image decreases, and the resolution decreases to the limit of the camera performance. Therefore, we attempt to improve the resolution by integrating the frames after applying super-resolution or center-of-gravity processing. The processed results indicate that center-of-gravity processing can be effective in pulsed-neutron imaging with a high-speed camera. In addition, the results show that super-resolution processing is effective indirectly. A project to develop a real-time image data processing system has begun, and this system will be used at J-PARC in JAEA. (author)

  8. Gamma spectrometry and plastic-scintillator inherent background

    International Nuclear Information System (INIS)

    Pomerantsev, V.V.; Gagauz, I.B.; Mitsai, L.I.; Pilipenko, V.S.; Solomonov, V.M.; Chernikov, V.V.; Tsirlin, Y.A.

    1988-01-01

    The authors measured the energy resolution for a linear dependence of light yield on gamma radiation energy of gamma spectrometers based on plastic scintillation detectors for several plastic scintillators. If there were several gamma lines from the source the line with the highest energy was used to eliminate distortion due to overlap from the Compton background from gamma radiation of higher energy. Attenuation lengths were calculated. The tests were based on three modes of interaction between the gamma radiation and the scintillator: Compton scattering, the photoelectric effect, and pair formation. The contribution from light collection was also considered. The scintillators tested included polystyrene, polymethyl methacrylate, cesium iodide, and sodium iodide. Gamma sources included cesium 137, sodium 22, potassium 40, yttrium 88, thorium 232, and plutonium-beryllium

  9. Lithium indium diselenide: A new scintillator for neutron imaging

    Energy Technology Data Exchange (ETDEWEB)

    Lukosi, Eric, E-mail: elukosi@utk.edu [University of Tennessee, Knoxville, TN (United States); Herrera, Elan; Hamm, Daniel; Lee, Kyung-Min [University of Tennessee, Knoxville, TN (United States); Wiggins, Brenden [Y-12 National Security Complex, Oak Ridge, TN (United States); Trtik, Pavel [Paul Scherrer Institut, Villigen CH-5232 (Switzerland); Penumadu, Dayakar; Young, Stephen [University of Tennessee, Knoxville, TN (United States); Santodonato, Louis; Bilheux, Hassina [Oak Ridge National Laboratory, Oak Ridge, TN (United States); Burger, Arnold; Matei, Liviu [Fisk University, Nashville, TN (United States); Stowe, Ashley C. [University of Tennessee, Knoxville, TN (United States); Y-12 National Security Complex, Oak Ridge, TN (United States)

    2016-09-11

    Lithium indium diselenide, {sup 6}LiInSe{sub 2} or LISe, is a newly developed neutron detection material that shows both semiconducting and scintillating properties. This paper reports on the performance of scintillating LISe crystals for its potential use as a converter screen for cold neutron imaging. The spatial resolution of LISe, determined using a 10% threshold of the Modulation Transfer Function (MTF), was found to not scale linearly with thickness. Crystals having a thickness of 450 µm or larger resulted in an average spatial resolution of 67 µm, and the thinner crystals exhibited an increase in spatial resolution down to the Nyquist frequency of the CCD. The highest measured spatial resolution of 198 µm thick LISe (27 µm) outperforms a commercial 50 µm thick ZnS(Cu):{sup 6}LiF scintillation screen by more than a factor of three. For the LISe dimensions considered in this study, it was found that the light yield of LISe did not scale with its thickness. However, absorption measurements indicate that the {sup 6}Li concentration is uniform and the neutron absorption efficiency of LISe as a function of thickness follows general nuclear theory. This suggests that the differences in apparent brightness observed for the LISe samples investigated may be due to a combination of secondary charged particle escape, scintillation light transport in the bulk and across the LISe-air interface, and variations in the activation of the scintillation mechanism. Finally, it was found that the presence of {sup 115}In and its long-lived {sup 116}In activation product did not result in ghosting (memory of past neutron exposure), demonstrating potential of LISe for imaging transient systems.

  10. Development of {sup 100}Mo-containing scintillating bolometers for a high-sensitivity neutrinoless double-beta decay search

    Energy Technology Data Exchange (ETDEWEB)

    Armengaud, E.; Gros, M.; Herve, S.; Magnier, P.; Navick, X.F.; Nones, C.; Paul, B.; Penichot, Y.; Zolotarova, A.S. [Universite Paris-Saclay, IRFU, CEA, Gif-sur-Yvette (France); Augier, C.; Billard, J.; Cazes, A.; Charlieux, F.; Jesus, M. de; Gascon, J.; Juillard, A.; Queguiner, E.; Sanglard, V.; Vagneron, L. [Univ Lyon, Universite Lyon 1, CNRS/IN2P3, IPN-Lyon, Villeurbanne (France); Barabash, A.S.; Konovalov, S.I.; Umatov, V.I. [National Research Centre Kurchatov Institute, Institute of Theoretical and Experimental Physics, Moscow (Russian Federation); Beeman, J.W. [Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Bekker, T.B. [V.S. Sobolev Institute of Geology and Mineralogy of the Siberian Branch of the RAS, Novosibirsk (Russian Federation); Bellini, F.; Ferroni, F. [Sapienza Universita di Roma, Dipartimento di Fisica, Rome (Italy); INFN, Sezione di Roma, Rome (Italy); Benoit, A.; Camus, P. [CNRS-Neel, Grenoble (France); Berge, L.; Chapellier, M.; Dumoulin, L.; Humbert, V.; Le Sueur, H.; Marcillac, P. de; Marnieros, S.; Marrache-Kikuchi, C.; Novati, V.; Olivieri, E.; Plantevin, O. [CSNSM, Univ. Paris-Sud, CNRS/IN2P3, Universite Paris-Saclay, Orsay (France); Bergmann, T.; Kleifges, M.; Tcherniakhovski, D.; Weber, M. [Karlsruhe Institute of Technology, Institut fuer Prozessdatenverarbeitung und Elektronik, Karlsruhe (Germany); Boiko, R.S.; Danevich, F.A.; Kobychev, V.V.; Nikolaichuk, M.O.; Tretyak, V.I. [Institute for Nuclear Research, Kyiv (Ukraine); Broniatowski, A. [CSNSM, Univ. Paris-Sud, CNRS/IN2P3, Universite Paris-Saclay, Orsay (France); Karlsruhe Institute of Technology, Institut fuer Experimentelle Teilchenphysik, Karlsruhe (Germany); Brudanin, V.; Rozov, S.; Yakushev, E. [JINR, Laboratory of Nuclear Problems, Dubna, Moscow Region (Russian Federation); Capelli, S.; Gironi, L.; Pavan, M.; Pessina, G. [Universita di Milano Bicocca, Dipartimento di Fisica, Milan (Italy); INFN, Sezione di Milano Bicocca, Milan (Italy); Cardani, L.; Casali, N.; Dafinei, I.; Tomei, C.; Vignati, M. [INFN, Sezione di Roma, Rome (Italy); Chernyak, D.M. [Institute for Nuclear Research, Kyiv (Ukraine); The University of Tokyo, Kavli Institute for the Physics and Mathematics of the Universe (WPI), The University of Tokyo Institutes for Advanced Study, Kashiwa, Chiba (Japan); Combarieu, M. de; Pari, P. [Universite Paris-Saclay, IRAMIS, CEA, Gif-sur-Yvette (France); Coron, N.; Redon, T. [Universite Paris-Sud, IAS, CNRS, Orsay (France); Devoyon, L.; Koskas, F.; Strazzer, O. [Universite Paris-Saclay, Orphee, CEA, Gif-sur-Yvette (France); Di Domizio, S. [Universita di Genova, Dipartimento di Fisica, Genoa (Italy); INFN Sezione di Genova, Genoa (Italy); Eitel, K.; Siebenborn, B. [Karlsruhe Institute of Technology, Institut fuer Kernphysik, Karlsruhe (Germany); Enss, C.; Fleischmann, A.; Gastaldo, L. [Heidelberg University, Kirchhoff Institute for Physics, Heidelberg (Germany); Foerster, N.; Kozlov, V. [Karlsruhe Institute of Technology, Institut fuer Experimentelle Teilchenphysik, Karlsruhe (Germany); Giuliani, A. [CSNSM, Univ. Paris-Sud, CNRS/IN2P3, Universite Paris-Saclay, Orsay (France); Universita dell' Insubria, DISAT, Como (Italy); Grigorieva, V.D.; Ivannikova, N.V.; Ivanov, I.M.; Makarov, E.P.; Shlegel, V.N.; Vasiliev, Ya.V. [Nikolaev Institute of Inorganic Chemistry, Novosibirsk (Russian Federation); Hehn, L. [Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Karlsruhe Institute of Technology, Institut fuer Kernphysik, Karlsruhe (Germany); Jin, Y. [Laboratoire de Photonique et de Nanostructures, CNRS, Marcoussis (France); Kraus, H. [University of Oxford, Department of Physics, Oxford (United Kingdom); Kudryavtsev, V.A. [University of Sheffield, Department of Physics and Astronomy, Sheffield (United Kingdom); Laubenstein, M.; Nagorny, S.; Pattavina, L.; Pirro, S. [INFN, Laboratori Nazionali del Gran Sasso, Assergi, AQ (Italy); Loidl, M.; Rodrigues, M. [CEA-Saclay, CEA, LIST, Laboratoire National Henri Becquerel (LNE-LNHB), Gif-sur-Yvette Cedex (France); Mancuso, M. [CSNSM, Univ. Paris-Sud, CNRS/IN2P3, Universite Paris-Saclay, Orsay (France); Universita dell' Insubria, DISAT, Como (Italy); Max-Planck-Institut fuer Physik, Munich (Germany); Pagnanini, L.; Schaeffner, K. [INFN, Laboratori Nazionali del Gran Sasso, Assergi, AQ (Italy); INFN, Gran Sasso Science Institute, L' Aquila (Italy); Piperno, G. [INFN, Laboratori Nazionali di Frascati, Rome (Italy); Poda, D.V. [CSNSM, Univ. Paris-Sud, CNRS/IN2P3, Universite Paris-Saclay, Orsay (France); Institute for Nuclear Research, Kyiv (Ukraine); Rusconi, C. [INFN, Laboratori Nazionali del Gran Sasso, Assergi, AQ (Italy); University of South Carolina, Department of Physics and Astronomy, Columbia, SC (United States); Scorza, S. [Karlsruhe Institute of Technology, Institut fuer Experimentelle Teilchenphysik, Karlsruhe (Germany); SNOLAB, Lively, ON (Canada); Velazquez, M. [Universite de Bordeaux, ICMCB, CNRS, Pessac (France)

    2017-11-15

    This paper reports on the development of a technology involving {sup 100}Mo-enriched scintillating bolometers, compatible with the goals of CUPID, a proposed next-generation bolometric experiment to search for neutrinoless double-beta decay. Large mass (∝ 1 kg), high optical quality, radiopure {sup 100}Mo-containing zinc and lithium molybdate crystals have been produced and used to develop high performance single detector modules based on 0.2-0.4 kg scintillating bolometers. In particular, the energy resolution of the lithium molybdate detectors near the Q-value of the double-beta transition of {sup 100}Mo (3034 keV) is 4-6 keV FWHM. The rejection of the α-induced dominant background above 2.6 MeV is better than 8σ. Less than 10 μBq/kg activity of {sup 232}Th({sup 228}Th) and {sup 226}Ra in the crystals is ensured by boule recrystallization. The potential of {sup 100}Mo-enriched scintillating bolometers to perform high sensitivity double-beta decay searches has been demonstrated with only 10 kg x d exposure: the two neutrino double-beta decay half-life of {sup 100}Mo has been measured with the up-to-date highest accuracy as T{sub 1/2} = [6.90 ± 0.15(stat.) ± 0.37(syst.)] x 10{sup 18} years. Both crystallization and detector technologies favor lithium molybdate, which has been selected for the ongoing construction of the CUPID-0/Mo demonstrator, containing several kg of {sup 100}Mo. (orig.)

  11. The high resolution spaghetti hadron calorimeter

    International Nuclear Information System (INIS)

    Jenni, P.; Sonderegger, P.; Paar, H.P.; Wigmans, R.

    1987-01-01

    It is proposed to build a prototype for a hadron calorimeter with scintillating plastic fibres as active material. The absorber material is lead. Provided that these components are used in the appropriate volume ratio, excellent performance may be expected, e.g. an energy resolution of 30%/√E for jet detection. The proposed design offers additional advantages compared to the classical sandwich calorimeter structures in terms of granularity, hermiticity, uniformity, compactness, readout, radiation resistivity, stability and calibration. 22 refs.; 7 figs

  12. Systematic studies of small scintillators for new sampling calorimeter

    Indian Academy of Sciences (India)

    A new sampling calorimeter using very thin scintillators and the multi-pixel photon counter (MPPC) has been proposed to produce better position resolution for the international linear collider (ILC) experiment. As part of this R & D study, small plastic scintillators of different sizes, thickness and wrapping reflectors are ...

  13. Acquiring beam data for a flattening-filter free linear accelerator using organic scintillators

    International Nuclear Information System (INIS)

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

    2013-01-01

    Fibre-coupled organic scintillators have been proven a credible alternative to clinically implemented methods for radiotherapy dosimetry, primarily due to their water equivalence and good spatial resolution. Furthermore, the fast response of the scintillators can be exploited to perform time-resolved dosimetry on a highly detailed level. In this study, we present beam data for a Varian TrueBeam linear accelerator, which is capable of delivering flattening-filter free (FFF 1 ) clinical X-ray beams. The beam data have been acquired using an in-house developed dosimetry system based on fibre-coupled organic scintillators. The presented data exhibit high accuracy and precision when compared with data obtained using commercial dosimetry methods, and agree well with results published in the literature. -- Highlights: •A dosimetry system based on fibre-coupled organic scintillators is presented. •The system is used for radiotherapy beams with and without flattening filter. •Measurements show good agreement with various commercial dosimeters

  14. Fine-pitch glass GEM for high-resolution X-ray imaging

    International Nuclear Information System (INIS)

    Fujiwara, T.; Toyokawa, H.; Mitsuya, Y.

    2016-01-01

    We have developed a fine-pitch glass gas electron multiplier (G-GEM) for high-resolution X-ray imaging. The fine-pitch G-GEM is made of a 400 μm thick photo-etchable glass substrate with 150 μm pitch holes. It is fabricated using the same wet etching technique as that for the standard G-GEM. In this work, we present the experimental results obtained with a single fine-pitch G-GEM with a 50 × 50 mm 2 effective area. We recorded an energy resolution of 16.2% and gas gain up to 5,500 when the detector was irradiated with 5.9 keV X-rays. We present a 50 × 50 mm 2 X-ray radiograph image acquired with a scintillation gas and optical readout system.

  15. High resolution tomography using analog coding

    International Nuclear Information System (INIS)

    Brownell, G.L.; Burnham, C.A.; Chesler, D.A.

    1985-01-01

    As part of a 30-year program in the development of positron instrumentation, the authors have developed a high resolution bismuth germanate (BGO) ring tomography (PCR) employing 360 detectors and 90 photomultiplier tubes for one plane. The detectors are shaped as trapezoid and are 4 mm wide at the front end. When assembled, they form an essentially continuous cylindrical detector. Light from a scintillation in the detector is viewed through a cylindrical light pipe by the photomultiplier tubes. By use of an analog coding scheme, the detector emitting light is identified from the phototube signals. In effect, each phototube can identify four crystals. PCR is designed as a static device and does not use interpolative motion. This results in considerable advantage when performing dynamic studies. PCR is the positron tomography analog of the γ-camera widely used in nuclear medicine

  16. Capillary detectors for high resolution tracking

    International Nuclear Information System (INIS)

    Annis, P.; Bay, A.; Bonekaemper, D.; Buontempo, S.; Ereditato, A.; Fabre, J.P.; Fiorillo, G.; Frekers, D.; Frenkel, A.; Galeazzi, F.; Garufi, F.; Goldberg, J.; Golovkin, S.; Hoepfner, K.; Konijn, J.; Kozarenko, E.; Kreslo, I.; Liberti, B.; Martellotti, G.; Medvedkov, A.; Mommaert, C.; Panman, J.; Penso, G.; Petukhov, Yu.; Rondeshagen, D.; Tyukov, V.; Vasilchenko, V.; Vilain, P.; Vischers, J.L.; Wilquet, G.; Winter, K.; Wolff, T.; Wong, H.

    1997-01-01

    We present a new tracking device based on glass capillary bundles or layers filled with highly purified liquid scintillator and read out at one end by means of image intensifiers and CCD devices. A large-volume prototype consisting of 5 x 10 5 capillaries with a diameter of 20 μm and a length of 180 cm and read out by a megapixel CCD has been tested with muon and neutrino beams at CERN. With this prototype a two track resolution of 33 μm was achieved with passing through muons. Images of neutrino interactions in a capillary bundle have also been acquired and analysed. Read-out chains based on electron bombarded CCD (EBCCD) and image pipeline devices are also investigated. Preliminary results obtained with a capillary bundle read out by an EBCCD are presented. (orig.)

  17. Comparison of the imaging performances for recently developed monolithic scintillators: CRY018 and CRY019 for dual isotope gamma ray imaging applications

    International Nuclear Information System (INIS)

    Polito, C.; Pani, R.; Trigila, C.; Cinti, M.N.; Fabbri, A.; Pellegrini, R.; Frantellizzi, V.; Vincentis, G. De; Pani, R.

    2017-01-01

    The growing interest for new scintillation crystals with outstanding imaging performances (i.e. resolution and efficiency) has suggested the study of recently discovered scintillators named CRY018 and CRY019 . The crystals under investigation are monolithic and have shown enhanced characteristics both for gamma ray spectrometry and for Nuclear Medicine imaging applications such as the dual isotope imaging. Moreover, the non-hygroscopic nature and the absence of afterglow make these scintillators even more attractive for the potential improvement in a wide range of applications. These scintillation crystals show a high energy resolution in the energy range involved in Nuclear Medicine, allowing the discrimination between very close energy values. Moreover, in order to prove their suitability of being powerful imaging systems, the imaging performances like the position linearity and the intrinsic spatial resolution have been evaluated obtaining satisfactory results thanks to the implementation of an optimized algorithm for the images reconstruction.

  18. Comparison of the imaging performances for recently developed monolithic scintillators: CRY018 and CRY019 for dual isotope gamma ray imaging applications

    Science.gov (United States)

    Polito, C.; Pani, R.; Trigila, C.; Cinti, M. N.; Fabbri, A.; Frantellizzi, V.; De Vincentis, G.; Pellegrini, R.; Pani, R.

    2017-01-01

    The growing interest for new scintillation crystals with outstanding imaging performances (i.e. resolution and efficiency) has suggested the study of recently discovered scintillators named CRY018 and CRY019. The crystals under investigation are monolithic and have shown enhanced characteristics both for gamma ray spectrometry and for Nuclear Medicine imaging applications such as the dual isotope imaging. Moreover, the non-hygroscopic nature and the absence of afterglow make these scintillators even more attractive for the potential improvement in a wide range of applications. These scintillation crystals show a high energy resolution in the energy range involved in Nuclear Medicine, allowing the discrimination between very close energy values. Moreover, in order to prove their suitability of being powerful imaging systems, the imaging performances like the position linearity and the intrinsic spatial resolution have been evaluated obtaining satisfactory results thanks to the implementation of an optimized algorithm for the images reconstruction.

  19. Scintillation properties of GSO

    International Nuclear Information System (INIS)

    Melcher, C.L.; Schweitzer, J.S.; Utsu, T.; Akiyama, S.

    1990-01-01

    The timing properties of Gd 2 SiO 5 :Ce (GSO) single crystal scintillators have previously been evaluated for positron emission tomography applications. The measured time resolution, however, was worse than expected from calculations based on photoelectron yield and a 60 nanosecond exponential decay constant, leading us to further investigate GSO's basic properties. With a time-correlated-single-photon technique, the authors have found two decay components, one of 56 ns and one of 600 ns, the latter containing 10--15% of the total scintillation output. This may explain the difference between the experimental and theoretical time resolutions and confirms a previous hypothesis of a long decay component. In addition, the authors have found that each component's decay constant strongly depends on the cerium concentration. The primary component varies from ∼ 20 ns to ∼ 190 ns and the secondary component varies from ∼ 70 ns to ∼ 1200 ns as the cerium concentration is varied from 5.0 mol% to 0.1 mol%

  20. Collimated trans-axial tomographic scintillation camera

    International Nuclear Information System (INIS)

    1980-01-01

    The principal problem in trans-axial tomographic radioisotope scanning is the length of time required to obtain meaningful data. Patient movement and radioisotope migration during the scanning period can cause distortion of the image. The object of this invention is to reduce the scanning time without degrading the images obtained. A system is described in which a scintillation camera detector is moved to an orbit about the cranial-caudal axis relative to the patient. A collimator is used in which lead septa are arranged so as to admit gamma rays travelling perpendicular to this axis with high spatial resolution and those travelling in the direction of the axis with low spatial resolution, thus increasing the rate of acceptance of radioactive events to contribute to the positional information obtainable without sacrificing spatial resolution. (author)

  1. 3D tomodosimetry using long scintillating fibers: A feasibility study

    International Nuclear Information System (INIS)

    Goulet, Mathieu; Archambault, Louis; Beaulieu, Luc; Gingras, Luc

    2013-01-01

    Purpose: 3D dosimetry is recognized as an ideal for patient-specific quality assurance (QA) of highly conformal radiotherapy treatments. However, existing 3D dosimeters are not straightforward to implement in the clinic, as their read-out procedure is often tedious and their accuracy, precision, and/or sample size exhibit limitations. The purpose of this work is to develop a 3D dosimeter based on the concept of tomodosimetry inside concentric cylindrical planes using long scintillating fibers for the QA of modern radiotherapy techniques such as intensity-modulated radiation therapy (IMRT) or intensity-modulated arc therapy (IMAT).Methods: Using a model-based simulation, scintillating fibers were modeled on three concentric cylindrical planes of radii 2.5, 5.0, and 7.5 cm, inside a 10 cm radius water-equivalent cylinder phantom. The phantom was set to rotate around its central axis, made parallel to the linac gantry axis of rotation. Light acquisitions were simulated using the calculated dose from the treatment planning software and reconstructed in each cylindrical plane at a resolution of 1 mm 2 using a total-variation minimization iterative reconstruction algorithm. The 3D dose was then interpolated from the reconstructed cylindrical plane doses at a resolution of 1 mm 3 . Different scintillating fiber patterns were compared by varying the angle of each fiber in its cylindrical plane and introducing a light-tight cut in each fiber. The precision of the reconstructed cylindrical dose distribution was evaluated using a Poisson modeling of the acquired light signals and the accuracy of the interpolated 3D dose was evaluated using an IMRT clinical plan for a prostate case.Results: Straight scintillating fiber patterns with light-tight cuts were the most accurate in cylindrical dose reconstruction, showing less than 0.5 mm distance-to-agreement in dose gradients and a mean local dose difference of less than 0.2% in the high dose region for a 10 × 10 cm 2 field. The

  2. Ionization and scintillation response of high-pressure xenon gas to alpha particles

    International Nuclear Information System (INIS)

    Álvarez, V; Cárcel, S; Cervera, A; Díaz, J; Ferrario, P; Gil, A; Gómez-Cadenas, J J; Borges, F I G; Conde, C A N; Fernandes, L M P; Freitas, E D C; Cebrián, S; Dafni, T; Gómez, H; Egorov, M; Gehman, V M; Goldschmidt, A; Esteve, R; Evtoukhovitch, P; Ferreira, A L

    2013-01-01

    High-pressure xenon gas is an attractive detection medium for a variety of applications in fundamental and applied physics. In this paper we study the ionization and scintillation detection properties of xenon gas at 10 bar pressure. For this purpose, we use a source of alpha particles in the NEXT-DEMO time projection chamber, the large scale prototype of the NEXT-100 neutrinoless double beta decay experiment, in three different drift electric field configurations. We measure the ionization electron drift velocity and longitudinal diffusion, and compare our results to expectations based on available electron scattering cross sections on pure xenon. In addition, two types of measurements addressing the connection between the ionization and scintillation yields are performed. On the one hand we observe, for the first time in xenon gas, large event-by-event correlated fluctuations between the ionization and scintillation signals, similar to that already observed in liquid xenon. On the other hand, we study the field dependence of the average scintillation and ionization yields. Both types of measurements may shed light on the mechanism of electron-ion recombination in xenon gas for highly-ionizing particles. Finally, by comparing the response of alpha particles and electrons in NEXT-DEMO, we find no evidence for quenching of the primary scintillation light produced by alpha particles in the xenon gas.

  3. Event localization in bulk scintillator crystals using coded apertures

    Energy Technology Data Exchange (ETDEWEB)

    Ziock, K.P. [Oak Ridge National Laboratory, Oak Ridge, TN (United States); Department of Physics and Astronomy, University of Tennessee, Knoxville, TN (United States); Braverman, J.B. [Department of Physics and Astronomy, University of Tennessee, Knoxville, TN (United States); Fabris, L.; Harrison, M.J.; Hornback, D.; Newby, J. [Oak Ridge National Laboratory, Oak Ridge, TN (United States)

    2015-06-01

    The localization of radiation interactions in bulk scintillators is generally limited by the size of the light distribution at the readout surface of the crystal/light-pipe system. By finding the centroid of the light spot, which is typically of order centimeters across, practical single-event localization is limited to ~2 mm/cm of crystal thickness. Similar resolution can also be achieved for the depth of interaction by measuring the size of the light spot. Through the use of near-field coded-aperture techniques applied to the scintillation light, light transport simulations show that for 3-cm-thick crystals, more than a five-fold improvement (millimeter spatial resolution) can be achieved both laterally and in event depth. At the core of the technique is the requirement to resolve the shadow from an optical mask placed in the scintillation light path between the crystal and the readout. In this paper, experimental results are presented that demonstrate the overall concept using a 1D shadow mask, a thin-scintillator crystal and a light pipe of varying thickness to emulate a 2.2-cm-thick crystal. Spatial resolutions of ~1 mm in both depth and transverse to the readout face are obtained over most of the crystal depth.

  4. Event localization in bulk scintillator crystals using coded apertures

    International Nuclear Information System (INIS)

    Ziock, K.P.; Braverman, J.B.; Fabris, L.; Harrison, M.J.; Hornback, D.; Newby, J.

    2015-01-01

    The localization of radiation interactions in bulk scintillators is generally limited by the size of the light distribution at the readout surface of the crystal/light-pipe system. By finding the centroid of the light spot, which is typically of order centimeters across, practical single-event localization is limited to ~2 mm/cm of crystal thickness. Similar resolution can also be achieved for the depth of interaction by measuring the size of the light spot. Through the use of near-field coded-aperture techniques applied to the scintillation light, light transport simulations show that for 3-cm-thick crystals, more than a five-fold improvement (millimeter spatial resolution) can be achieved both laterally and in event depth. At the core of the technique is the requirement to resolve the shadow from an optical mask placed in the scintillation light path between the crystal and the readout. In this paper, experimental results are presented that demonstrate the overall concept using a 1D shadow mask, a thin-scintillator crystal and a light pipe of varying thickness to emulate a 2.2-cm-thick crystal. Spatial resolutions of ~1 mm in both depth and transverse to the readout face are obtained over most of the crystal depth

  5. Scintillator concept of NeuLAND at R3B

    Energy Technology Data Exchange (ETDEWEB)

    Aumann, Thomas; Ignatov, Alexander [Technische Universitaet Darmstadt (Germany); Boretzky, Konstanze; Heil, Michael; Simon, Haik [GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany); Maroussov, Vassili [Institut fuer Kernphysik, Universitaet zu Koeln (Germany); GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany); Zilges, Andreas [Institut fuer Kernphysik, Universitaet zu Koeln (Germany); Collaboration: R3B-Collaboration

    2011-07-01

    For the R3B experiment at FAIR a detection system for fast neutrons, NeuLAND (new Large Area Neutron Detector), is foreseen. Besides a time resolution of {sigma}{sub t}{approx_equal} 100 ps, spatial resolutions of {sigma}{sub x,y,z}{approx_equal} 1 cm, the detection efficiency of above 90% for neutrons of 0.2-1 GeV and a dedicated multi-neutron recognition capability are demanded. Using the FLUKA Monte Carlo code we studied a NeuLAND detector concept relying entirely on bars of a plastic scintillator (BC408). With a detector depth of 2 m the required efficiency is reached and the fraction of incident neutrons detected within resolution requirements varies from {proportional_to}70% to 80% in the desired energy range. Simulations have verified that the introduction of an inactive converter like iron deteriorates the timing performance. Due to the low density of the scintillator secondary protons typically cross several modules, thus allowing the tracking of secondaries. The status of the multi-hit recognition algorithm using the tracking information is presented along with the latest results for the scintillator prototypes for NeuLAND. Using the same framework a competing concept for NeuLAND based on MRPCs was studied as well and is contrasted to the scintillator concept.

  6. Inorganic-organic rubbery scintillators

    CERN Document Server

    Gektin, A V; Pogorelova, N; Neicheva, S; Sysoeva, E; Gavrilyuk, V

    2002-01-01

    Spectral-kinetic luminescence properties of films, containing homogeneously dispersed scintillation particles of CsI, CsI:Tl, CsI:Na, and NaI:Tl in optically transparent organosiloxane matrix, are presented. Material is flexible and rubbery and in consequence the detectors of convenient shapes can be produced. It is found that luminescence spectra of the received films are identical whereas decay times are much shorter compared to the same ones of the corresponding single crystals. Layers with pure CsI demonstrate only the fast UV emission (307 nm, 10 ns) without blue microsecond afterglow typical for crystals. The films containing NaI:Tl are non-hygroscopic and preserve scintillation properties for a long time in humid atmosphere unlike single crystals. Organosiloxane layers with CsI:Tl particles provide high light output with good energy resolution for sup 5 sup 5 Fe, sup 1 sup 0 sup 9 Cd, sup 2 sup 4 sup 1 Am sources, and are capable of detecting both X-rays and alpha-, beta-particles.

  7. Unified MTF for scintillator-coupled CMOS sensor

    International Nuclear Information System (INIS)

    Kim, Kwang Hyun; Kang, Dong-Wan; Kim, Dong Ki; Kim, Yong-Kyun

    2007-01-01

    The spatial resolution of scintillator-coupled CMOS sensor has been investigated from intrinsic sensor Modulation Transfer Function (MTF) to system MTF for the conditions of the digital radiography. For the intrinsic sensor MTF, the geometric MTF (gMTF) and the unified MTF (uMTF) were compared by analytic calculations for various pixel sizes. The effects of the initial dark signal of the sensor were considered in the calculation of the uMTF and reflected in a newly developed semi-empirical model. The measured system MTF and the calculated system MTF including semi-empirical model were compared under radiography conditions of 28 and 80 kVp. From the results, the calculated system MTF reflecting the dark-signal contribution on the sensor resolution did fit for the measured system resolution, and the higher the fraction of an initial dark signal to an output signal in response to X-ray exposure showed more degradation of the system resolution even with same scintillator and sensor

  8. Optimization of a scintillation detector with hemispherical configuration

    International Nuclear Information System (INIS)

    Saules Mendonca, A.C. de.

    1980-08-01

    A hemispherical configuration for scintillation detectors, is introduced so as to minimize the dispersion in light collection by reducing the number of reflexions. Better results in the process of light collection appear explicitly in the gain in the amplitude of the pulse and a better resolution in time and energy when a comparative analysis is made between the cylindrical and hemispherical geometries. The measurements were made using NE102, a plastic scintillator with cylindrical and hemispherical forms, comparing the results of pulse amplitude and energy resolution. The results were quite significant showing a 13% improvement in pulse amplitude and more than 10% in energy resolution for some values of energies from 511 KeV to 1275 KeV. (Author) [pt

  9. Time resolution deterioration with increasing crystal length in a TOF-PET system

    CERN Document Server

    Gundacker, S; Auffray, E; Jarron, P; Meyer, T; Lecoq, P

    2014-01-01

    Highest time resolution in scintillator based detectors is becoming more and more important. In medical detector physics L(Y)SO scintillators are commonly used for time of flight positron emission tomography (TOF-PET). Coincidence time resolutions (CTRs) smaller than 100 ps FWHM are desirable in order to improve the image signal to noise ratio and thus give benefit to the patient by shorter scanning times. Also in high energy physics there is the demand to improve the timing capabilities of calorimeters down to 10 ps. To achieve these goals it is important to study the whole chain, i.e. the high energy particle interaction in the crystal, the scintillation process itself, the scintillation light transfer in the crystal, the photodetector and the electronics. Time resolution measurements for a PET like system are performed with the time-over-threshold method in a coincidence setup utilizing the ultra-fast amplifier-discriminator NINO. With 2×2×3 mm3 LSO:Ce codoped 0.4%Ca crystals coupled to commercially avai...

  10. GPS scintillations and total electron content climatology in the southern low, middle and high latitude regions

    Directory of Open Access Journals (Sweden)

    Luca Spogli

    2013-06-01

    Full Text Available In recent years, several groups have installed high-frequency sampling receivers in the southern middle and high latitude regions, to monitor ionospheric scintillations and the total electron content (TEC changes. Taking advantage of the archive of continuous and systematic observations of the ionosphere on L-band by means of signals from the Global Positioning System (GPS, we present the first attempt at ionospheric scintillation and TEC mapping from Latin America to Antarctica. The climatology of the area considered is derived through Ground-Based Scintillation Climatology, a method that can identify ionospheric sectors in which scintillations are more likely to occur. This study also introduces the novel ionospheric scintillation 'hot-spot' analysis. This analysis first identifies the crucial areas of the ionosphere in terms of enhanced probability of scintillation occurrence, and then it studies the seasonal variation of the main scintillation and TEC-related parameters. The results produced by this sophisticated analysis give significant indications of the spatial/ temporal recurrences of plasma irregularities, which contributes to the extending of current knowledge of the mechanisms that cause scintillations, and consequently to the development of efficient tools to forecast space-weather-related ionospheric events.

  11. Development of TOF-PET using Compton scattering by plastic scintillators

    International Nuclear Information System (INIS)

    Kuramoto, M.; Nakamori, T.; Kimura, S.; Gunji, S.; Takakura, M.; Kataoka, J.

    2017-01-01

    We propose a time-of-flight (TOF) technique using plastic scintillators which have fast decay time of a few ns for positron emission tomography (PET). While the photoelectric absorption probability of the plastic for 511 keV gamma rays are extremely low due to its small density and effective atomic number, the cross section of Compton scattering is comparable to that of absorption by conventional inorganic scintillators. We thus propose TOF-PET using Compton scattering with plastic scintillators (Compton-PET), and performed fundamental experiments towards exploration of the Compton-PET capability. We demonstrated that the plastic scintillators achieved the better time resolution in comparison to LYSO(Ce) and GAGG(Ce) scintillators. In addition we evaluated the depth-of-interaction resolving capability with the plastic scintillators.

  12. Development of TOF-PET using Compton scattering by plastic scintillators

    Energy Technology Data Exchange (ETDEWEB)

    Kuramoto, M., E-mail: kuramoto@maxwell.kj.yamagata-u.ac.jp [Yamagata University, Kojirakawa 1-4-12, Yamagata 990-8560 (Japan); Nakamori, T., E-mail: nakamori@maxwell.kj.yamagata-u.ac.jp [Yamagata University, Kojirakawa 1-4-12, Yamagata 990-8560 (Japan); Kimura, S.; Gunji, S.; Takakura, M. [Yamagata University, Kojirakawa 1-4-12, Yamagata 990-8560 (Japan); Kataoka, J. [Waseda University, Okubo 3-4-1, Shinjuku, Tokyo 169-8555 (Japan)

    2017-02-11

    We propose a time-of-flight (TOF) technique using plastic scintillators which have fast decay time of a few ns for positron emission tomography (PET). While the photoelectric absorption probability of the plastic for 511 keV gamma rays are extremely low due to its small density and effective atomic number, the cross section of Compton scattering is comparable to that of absorption by conventional inorganic scintillators. We thus propose TOF-PET using Compton scattering with plastic scintillators (Compton-PET), and performed fundamental experiments towards exploration of the Compton-PET capability. We demonstrated that the plastic scintillators achieved the better time resolution in comparison to LYSO(Ce) and GAGG(Ce) scintillators. In addition we evaluated the depth-of-interaction resolving capability with the plastic scintillators.

  13. Development of TOF-PET using Compton scattering by plastic scintillators

    Science.gov (United States)

    Kuramoto, M.; Nakamori, T.; Kimura, S.; Gunji, S.; Takakura, M.; Kataoka, J.

    2017-02-01

    We propose a time-of-flight (TOF) technique using plastic scintillators which have fast decay time of a few ns for positron emission tomography (PET). While the photoelectric absorption probability of the plastic for 511 keV gamma rays are extremely low due to its small density and effective atomic number, the cross section of Compton scattering is comparable to that of absorption by conventional inorganic scintillators. We thus propose TOF-PET using Compton scattering with plastic scintillators (Compton-PET), and performed fundamental experiments towards exploration of the Compton-PET capability. We demonstrated that the plastic scintillators achieved the better time resolution in comparison to LYSO(Ce) and GAGG(Ce) scintillators. In addition we evaluated the depth-of-interaction resolving capability with the plastic scintillators.

  14. The ZEUS uranium-scintillator calorimeter for HERA

    International Nuclear Information System (INIS)

    Hilger, E.

    1987-01-01

    The high resolution calorimeter for the ZEUS detector at HERA is presented. The choice of a sandwich calorimeter from depleted uranium plates and plastic scintillator was made to accomplish compensation and thus the best possible energy resolution for hadrons and jets. The calorimeter is segmented transversely into towers and longitudinally into an electromagnetic and one or two hadronic sections. It is divided in a forward, barrel and rear part which surround hermetically the interaction region and the inner detectors. The expected energy resolutions are for electrons σ(E)/E = 0.15/√E, and for hadrons σ(E)/E = 0.35/√E, with a constant term of maximum 2% added in quadrature. First results from calorimeter test measurements are presented. (orig.)

  15. Extruding plastic scintillator at Fermilab

    International Nuclear Information System (INIS)

    Pla-Dalmau, Anna; Bross, Alain D.; Rykalin, Viktor V.

    2003-01-01

    An understanding of the costs involved in the production of plastic scintillators and the development of a less expensive material have become necessary with the prospects of building very large plastic scintillation detectors. Several factors contribute to the high cost of plastic scintillating sheets, but the principal reason is the labor-intensive nature of the manufacturing process. In order to significantly lower the costs, the current casting procedures had to be abandoned. Since polystyrene is widely used in the consumer industry, the logical path was to investigate the extrusion of commercial-grade polystyrene pellets with dopants to yield high quality plastic scintillator. This concept was tested and high quality extruded plastic scintillator was produced. The D0 and MINOS experiments are already using extruded scintillator strips in their detectors. An extrusion line has recently been installed at Fermilab in collaboration with NICADD (Northern Illinois Center for Accelerator and Detector Development). This new facility will serve to further develop and improve extruded plastic scintillator. This paper will discuss the characteristics of extruded plastic scintillator and its raw materials, the different manufacturing techniques and the current R andD program at Fermilab

  16. Test beam results from a scintillating fibers-lead calorimeter

    International Nuclear Information System (INIS)

    Caria, M.

    1991-01-01

    The SpaCal collaboration has built prototypes of lead-scintillating fibers calorimter. The aim is to check predicted performances. Here are briefly mentioned results obtained from prototypes tests in beam of e, π, μ at CERN. Layers 2m long of extruded lead, were equipped with 1mm fibers in an hexagonal geometry. The ratio of scintillator to lead was 1/4. Results are presented on the most appealing features of such a calorimeter: energy resolution, homogeneity, containment and compensation. It is shown, that excellent energy resolution togehter with compensation has been achieved. (orig.)

  17. Study of micro pixel photon counters for a high granularity scintillator-based hadron calorimeter

    International Nuclear Information System (INIS)

    D'Ascenzo, N.; Eggemann, A.; Garutti, E.

    2007-11-01

    A new Geiger mode avalanche photodiode, the Micro Pixel Photon Counter (MPPC), was recently released by Hamamatsu. It has a high photo-detection efficiency in the 420 nm spectral region. This product can represent an elegant candidate for the design of a high granularity scintillator based hadron calorimeter for the International Linear Collider. In fact, the direct readout of the blue scintillation photons with a MPPC is a feasible techological solution. The readout of a plastic scintillator by a MPPC, both mediated by the traditional wavelength shifting fiber, and directly coupled, has been systematically studied. (orig.)

  18. First scintillating bolometer tests of a CLYMENE R&D on Li2MoO4 scintillators towards a large-scale double-beta decay experiment

    Science.gov (United States)

    Buşe, G.; Giuliani, A.; de Marcillac, P.; Marnieros, S.; Nones, C.; Novati, V.; Olivieri, E.; Poda, D. V.; Redon, T.; Sand, J.-B.; Veber, P.; Velázquez, M.; Zolotarova, A. S.

    2018-05-01

    A new R&D on lithium molybdate scintillators has begun within a project CLYMENE (Czochralski growth of Li2MoO4 crYstals for the scintillating boloMeters used in the rare EveNts sEarches). One of the main goals of the CLYMENE is a realization of a Li2MoO4 crystal growth line to be complementary to the one recently developed by LUMINEU in view of a mass production capacity for CUPID, a next-generation tonne-scale bolometric experiment to search for neutrinoless double-beta decay. In the present paper we report the investigation of performance and radiopurity of 158-g and 13.5-g scintillating bolometers based on a first large-mass (230 g) Li2MoO4 crystal scintillator developed within the CLYMENE project. In particular, a good energy resolution (2-7 keV FWHM in the energy range of 0.2-5 MeV), one of the highest light yield (0.97 keV/MeV) amongst Li2MoO4 scintillating bolometers, an efficient alpha particles discrimination (10 σ) and potentially low internal radioactive contamination (below 0.2-0.3 mBq/kg of U/Th, but 1.4 mBq/kg of 210Po) demonstrate prospects of the CLYMENE in the development of high quality and radiopure Li2MoO4 scintillators for CUPID.

  19. X-ray detection capability of a Cs2ZnCl4 single-crystal scintillator

    International Nuclear Information System (INIS)

    Yahaba, Natsuna; Koshimizu, Masanori; Sun, Yan; Asai, Keisuke; Yanagida, Takayuki; Fujimoto, Yutaka; Haruki, Rie; Nishikido, Fumihiko; Kishimoto, Shunji

    2014-01-01

    The X-ray detection capability of a scintillation detector equipped with a Cs 2 ZnCl 4 single crystal was evaluated. The scintillation decay kinetics can be expressed as the sum of two exponential decay components. The fast decay component had a decay time constant of 1.8 ns, and its relative intensity was 95%. The total light output was 630 photons/MeV, and a subnanosecond timing resolution of 0.66 ns was obtained. The detection efficiency of 67.4 keV X-rays was 80% for a detector equipped with a 2.2-mm-thick Cs 2 ZnCl 4 crystal. Thus, excellent timing resolution and high detection efficiency were achieved simultaneously. (author)

  20. Scintillator studies for the HPD-PET concept

    CERN Document Server

    Braem, D; Ciocia, F; De Leo, R; Joram, C; Lagamba, L; Nappi, E; Séguinot, Jacques; Vilardi, I; Weilhammer, P

    2007-01-01

    The spatial, energy, and time resolutions of 10 cm long polished YAP:Ce and LYSO:Ce crystals have been measured. The work is part of the novel HPD-PET concept, based on a full three-dimensional, free of parallax errors, reconstruction of the γ-ray interaction point in 10–15 cm long scintillators. The effective light attenuation length, a key parameter of the HPD-PET concept, and the resolutions have been measured for various wrappings and coatings of the crystal lateral surfaces. Even if the final HPD-PET prototype could use scintillators and/or wrappings different from those tested, the results here presented prove the feasibility of the concept and provide hints on its potential capabilities.

  1. Novel scintillating material 2-(4-styrylphenyl)benzoxazole for the fully digital and MRI compatible J-PET tomograph based on plastic scintillators.

    Science.gov (United States)

    Wieczorek, Anna; Dulski, Kamil; Niedźwiecki, Szymon; Alfs, Dominika; Białas, Piotr; Curceanu, Catalina; Czerwiński, Eryk; Danel, Andrzej; Gajos, Aleksander; Głowacz, Bartosz; Gorgol, Marek; Hiesmayr, Beatrix; Jasińska, Bożena; Kacprzak, Krzysztof; Kamińska, Daria; Kapłon, Łukasz; Kochanowski, Andrzej; Korcyl, Grzegorz; Kowalski, Paweł; Kozik, Tomasz; Krzemień, Wojciech; Kubicz, Ewelina; Kucharek, Mateusz; Mohammed, Muhsin; Pawlik-Niedźwiecka, Monika; Pałka, Marek; Raczyński, Lech; Rudy, Zbigniew; Rundel, Oleksandr; Sharma, Neha G; Silarski, Michał; Uchacz, Tomasz; Wiślicki, Wojciech; Zgardzińska, Bożena; Zieliński, Marcin; Moskal, Paweł

    2017-01-01

    A novel plastic scintillator is developed for the application in the digital positron emission tomography (PET). The novelty of the concept lies in application of the 2-(4-styrylphenyl)benzoxazole as a wavelength shifter. The substance has not been used as scintillator dopant before. A dopant shifts the scintillation spectrum towards longer wavelengths making it more suitable for applications in scintillators of long strips geometry and light detection with digital silicon photomultipliers. These features open perspectives for the construction of the cost-effective and MRI-compatible PET scanner with the large field of view. In this article we present the synthesis method and characterize performance of the elaborated scintillator by determining its light emission spectrum, light emission efficiency, rising and decay time of the scintillation pulses and resulting timing resolution when applied in the positron emission tomography. The optimal concentration of the novel wavelength shifter was established by maximizing the light output and it was found to be 0.05 ‰ for cuboidal scintillator with dimensions of 14 mm x 14 mm x 20 mm.

  2. Measurement of light emission in scintillation vials

    International Nuclear Information System (INIS)

    Duran Ramiro, M. Teresa; Garcia-Torano, Eduardo

    2005-01-01

    The efficiency and energy resolution of liquid scintillation counting (LSC) systems are strongly dependent on the optical characteristics of scintillators, vials, and reflectors. This article presents the results of measurements of the light-emission profile of scintillation vials. Two measurement techniques, autoradiographs and direct measurements with a photomultiplier tube, have been used to obtain light-emission distribution for standard vials of glass, etched glass and polyethylene. Results obtained with both techniques are in good agreement. For the first time, the effect of the meniscus in terms of light contribution has been numerically estimated. These results can help design LSC systems that are more efficient in terms of light collection

  3. Construction techniques of the high resolution lead / scintillating fibre electromagnetic calorimeter for the KLOE experiment

    International Nuclear Information System (INIS)

    Anelli, M.; Bisogni, G.; Ceccarelli, A.

    1997-07-01

    The electromagnetic calorimeter of the KLOE experiment is a lead-scintillating fibre sampling device. This calorimeter is arranged as a 'barrel', closed at both ends with an 'end-cap'. The barrel consists in 24 modules defining a cylinder, 4.3 long, with 4 m inner diameter. Each end-cap consists of 32 modules running vertically along the chords of the circle inscribed into the barrel. In this paper the calorimeter construction techniques are described

  4. Construction techniques of the high resolution lead / scintillating fibre electromagnetic calorimeter for the KLOE experiment

    Energy Technology Data Exchange (ETDEWEB)

    Anelli, M; Bisogni, G; Ceccarelli, A [INFN, Laboratori Nazionali di Frascati, Rome (Italy); and others

    1997-07-01

    The electromagnetic calorimeter of the KLOE experiment is a lead-scintillating fibre sampling device. This calorimeter is arranged as a `barrel`, closed at both ends with an `end-cap`. The barrel consists in 24 modules defining a cylinder, 4.3 long, with 4 m inner diameter. Each end-cap consists of 32 modules running vertically along the chords of the circle inscribed into the barrel. In this paper the calorimeter construction techniques are described.

  5. A positron emission tomograph designed for 3/4 mm resolution

    International Nuclear Information System (INIS)

    McInytre, J.A.; Allen, R.D.; Aguiar, J.; Paulson, J.T.

    1995-01-01

    Two factors of the design for a positron tomograph affect the magnitude of the tomograph spatial resolution: the gamma ray detector width and the analogue measurement of the scintillator location. In the tomograph design reported here the analogue measurement is eliminated and the detector transaxial width factor is reduced to 3/4 mm. The analogue measurement is eliminated by transmitting the scintillation light from each individual scintillator through optical fibers to four photo-multipliers (PMT's); the identities of the PMT's then provide a digital address for the scintillation location. Plastic scintillators are used to provide enough scintillation light for transmission through the optical fibers. Bonuses from the use of plastic scintillators are first, the reduction of the scintillator dead time to about 10 nsec, second, a large reduction of cross-talk between neighboring scintillators, third, the reduction of resolution loss from off-axis gamma rays and, fourth, the ability to sample the axial image at one-eighth the axial resolution distance of 2.5 mm. The designed tomograph incorporates 20 rings. Two of the 32 tomograph 20-ring modules have been constructed to measure the resolution and other characteristics of the tomographs

  6. Liquid scintillator for 2D dosimetry for high-energy photon beams

    International Nuclear Information System (INIS)

    Poenisch, Falk; Archambault, Louis; Briere, Tina Marie; Sahoo, Narayan; Mohan, Radhe; Beddar, Sam; Gillin, Michael T.

    2009-01-01

    Complex radiation therapy techniques require dosimetric verification of treatment planning and delivery. The authors investigated a liquid scintillator (LS) system for application for real-time high-energy photon beam dosimetry. The system was comprised of a transparent acrylic tank filled with liquid scintillating material, an opaque outer tank, and a CCD camera. A series of images was acquired when the tank with liquid scintillator was irradiated with a 6 MV photon beam, and the light data measured with the CCD camera were filtered to correct for scattering of the optical light inside the liquid scintillator. Depth-dose and lateral profiles as well as two-dimensional (2D) dose distributions were found to agree with results from the treatment planning system. Further, the corrected light output was found to be linear with dose, dose rate independent, and is robust for single or multiple acquisitions. The short time needed for image acquisition and processing could make this system ideal for fast verification of the beam characteristics of the treatment machine. This new detector system shows a potential usefulness of the LS for 2D QA.

  7. Liquid scintillator for 2D dosimetry for high-energy photon beams

    Energy Technology Data Exchange (ETDEWEB)

    Poenisch, Falk; Archambault, Louis; Briere, Tina Marie; Sahoo, Narayan; Mohan, Radhe; Beddar, Sam; Gillin, Michael T. [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, 1515 Holcombe Boulevard., Unit 94, Houston, Texas 77030 (United States)

    2009-05-15

    Complex radiation therapy techniques require dosimetric verification of treatment planning and delivery. The authors investigated a liquid scintillator (LS) system for application for real-time high-energy photon beam dosimetry. The system was comprised of a transparent acrylic tank filled with liquid scintillating material, an opaque outer tank, and a CCD camera. A series of images was acquired when the tank with liquid scintillator was irradiated with a 6 MV photon beam, and the light data measured with the CCD camera were filtered to correct for scattering of the optical light inside the liquid scintillator. Depth-dose and lateral profiles as well as two-dimensional (2D) dose distributions were found to agree with results from the treatment planning system. Further, the corrected light output was found to be linear with dose, dose rate independent, and is robust for single or multiple acquisitions. The short time needed for image acquisition and processing could make this system ideal for fast verification of the beam characteristics of the treatment machine. This new detector system shows a potential usefulness of the LS for 2D QA.

  8. On the use of single large-area photodiodes in scintillation counters

    International Nuclear Information System (INIS)

    Morrell, C.

    1989-12-01

    The compilation of this review was originally intended to assess the possibility of using photodiode-based scintillation counters in fluorescence EXAFS (or FLEXAFS) systems as a low-cost alternative to photomultiplier-based counters. The X-ray energies encountered in FLEXAFS experiments range from a few keV to a few tens of keV, and detectors are required to have some energy resolution and/or high count-rate capability in order to optimize the quality of data collected. The results presented in the reviewed literature imply strongly that photodiodes do not compete successfully with photomultipliers in scintillation counting systems for X-ray energies below the order of 100keV, at least at the present stage of photodiode technology. Nevertheless it is likely that there are other applications requiring X-ray detectors for which a photodiode-based scintillation counter may be perfectly adequate, and it is therefore felt that such a review is still useful. In addition, large-area single photodiodes have much to offer as X-ray detectors in their own right, and several of the considerations regarding their use in scintillation counters are highly relevant to this application. (author)

  9. Scintillation camera for high activity sources

    International Nuclear Information System (INIS)

    Arseneau, R.E.

    1978-01-01

    The invention described relates to a scintillation camera used for clinical medical diagnosis. Advanced recognition of many unacceptable pulses allows the scintillation camera to discard such pulses at an early stage in processing. This frees the camera to process a greater number of pulses of interest within a given period of time. Temporary buffer storage allows the camera to accommodate pulses received at a rate in excess of its maximum rated capability due to statistical fluctuations in the level of radioactivity of the radiation source measured. (U.K.)

  10. Scintillation camera with improved output means

    International Nuclear Information System (INIS)

    Lange, K.; Wiesen, E.J.; Woronowicz, E.M.

    1978-01-01

    In a scintillation camera system, the output pulse signals from an array of photomultiplier tubes are coupled to the inputs of individual preamplifiers. The preamplifier output signals are coupled to circuitry for computing the x and y coordinates of the scintillations. A cathode ray oscilloscope is used to form an image corresponding with the pattern in which radiation is emitted by a body. Means for improving the uniformity and resolution of the scintillations are provided. The means comprise biasing means coupled to the outputs of selected preamplifiers so that output signals below a predetermined amplitude are not suppressed and signals falling within increasing ranges of amplitudes are increasingly suppressed. In effect, the biasing means make the preamplifiers non-linear for selected signal levels

  11. Characterisation of cerium-doped lanthanum bromide scintillation detector

    International Nuclear Information System (INIS)

    Etim, I. P.; Obu, J. A.; Ushie, J. O.

    2011-01-01

    LaBr 3 (Ce) crystals is one of the new scintillating detectors that has been developed in recent years which has proven to be superior to other scintillating materials in terms of resolution and efficiency. The energy resolution, intrinsic photo peak, total intrinsic and total absolute efficiency of this detector have been measured for a 25mm x 25mm Brillance T M 380 LaBr 3 (Ce) detector. The energy dependence of the resolution has been studied with a variety of gamma ray sources with variable energy range (122KeV-1408KeV). LaBr 3 (Ce) detector shows an excellent energy resolution of 2.6% (FWHM) at 662KeV photons ( 137 Cs source) at room temperature. A full-energy peak efficiency of 90.1-4.3% has been obtained for the 122 - 1408KeV energy range for a source-detector distance of 150mm.

  12. Detection of cosmic ray tracks using scintillating fibers and position sensitive multi-anode photomultipliers

    International Nuclear Information System (INIS)

    Atac, M.; Streets, J.; Wilcer, N.

    1998-02-01

    This experiment demonstrates detection of cosmic ray tracks by using Scintillating fiber planes and multi-anode photomultipliers (MA-PMTs). In a laboratory like this, cosmic rays provide a natural source of high-energy charged particles which can be detected with high efficiency and with nanosecond time resolution

  13. X-ray detection capabilities of plastic scintillators incorporated with hafnium oxide nanoparticles surface-modified with phenyl propionic acid

    Science.gov (United States)

    Hiyama, Fumiyuki; Noguchi, Takio; Koshimizu, Masanori; Kishimoto, Shunji; Haruki, Rie; Nishikido, Fumihiko; Yanagida, Takayuki; Fujimoto, Yutaka; Aida, Tsutomu; Takami, Seiichi; Adschiri, Tadafumi; Asai, Keisuke

    2018-01-01

    We synthesized plastic scintillators incorporated with HfO2 nanoparticles as detectors for X-ray synchrotron radiation. Nanoparticles with sizes of less than 10 nm were synthesized with the subcritical hydrothermal method. The detection efficiency of high-energy X-ray photons improved by up to 3.3 times because of the addition of the nanoparticles. Nanosecond time resolution was successfully achieved for all the scintillators. These results indicate that this method is applicable for the preparation of plastic scintillators to detect X-ray synchrotron radiation.

  14. Maximum likelihood positioning algorithm for high-resolution PET scanners

    International Nuclear Information System (INIS)

    Gross-Weege, Nicolas; Schug, David; Hallen, Patrick; Schulz, Volkmar

    2016-01-01

    Purpose: In high-resolution positron emission tomography (PET), lightsharing elements are incorporated into typical detector stacks to read out scintillator arrays in which one scintillator element (crystal) is smaller than the size of the readout channel. In order to identify the hit crystal by means of the measured light distribution, a positioning algorithm is required. One commonly applied positioning algorithm uses the center of gravity (COG) of the measured light distribution. The COG algorithm is limited in spatial resolution by noise and intercrystal Compton scatter. The purpose of this work is to develop a positioning algorithm which overcomes this limitation. Methods: The authors present a maximum likelihood (ML) algorithm which compares a set of expected light distributions given by probability density functions (PDFs) with the measured light distribution. Instead of modeling the PDFs by using an analytical model, the PDFs of the proposed ML algorithm are generated assuming a single-gamma-interaction model from measured data. The algorithm was evaluated with a hot-rod phantom measurement acquired with the preclinical HYPERION II D PET scanner. In order to assess the performance with respect to sensitivity, energy resolution, and image quality, the ML algorithm was compared to a COG algorithm which calculates the COG from a restricted set of channels. The authors studied the energy resolution of the ML and the COG algorithm regarding incomplete light distributions (missing channel information caused by detector dead time). Furthermore, the authors investigated the effects of using a filter based on the likelihood values on sensitivity, energy resolution, and image quality. Results: A sensitivity gain of up to 19% was demonstrated in comparison to the COG algorithm for the selected operation parameters. Energy resolution and image quality were on a similar level for both algorithms. Additionally, the authors demonstrated that the performance of the ML

  15. Use of a YAP:Ce matrix coupled to a position-sensitive photomultiplier for high resolution positron emission tomography

    International Nuclear Information System (INIS)

    Del Guerra, A.; Zavattini, G.; Notaristefani, F. de; Giganti, M.; Piffanelli, A.; Pani, R.; Turra, A.

    1996-01-01

    A new scintillation detector system has been designed for application in high resolution Positron Emission Tomography (PET). The detector is a bundle of small YAlO 3 :Ce (YAP) crystals closely packed (0.2 x 0.2 x 3.0 cm 3 ), coupled to a position sensitive photomultiplier tube (PSPMT). The preliminary results obtained for spatial resolution, time resolution, energy resolution and efficiency of two such detectors working in coincidence are presented. These are 1.2 mm for the FWHM spatial resolution, 2.0 ns for the FWHM time resolution and 20% for the FWHM energy resolution at 511 keV. The measured efficiency is (44 ± 3)% with a 150 keV threshold and (20 ± 2)% with a 300 keV threshold

  16. Scintillation properties of Ce:(La,Gd){sub 2}Si{sub 2}O{sub 7} at high temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Kurosawa, Shunsuke, E-mail: kurosawa@imr.tohoku.ac.jp [Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Miyagi (Japan); New Industry Creation Hatchery Center (NICHe), Tohoku University, 6-6-10 Aoba, Aramaki, Aoba-ku, Sendai 980-8579, Miyagi (Japan); Shishido, Toetsu; Sugawara, Takamasa; Nomura, Akiko; Yubuta, Kunio; Suzuki, Akira; Murakami, Rikito [Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Miyagi (Japan); Pejchal, Jan [New Industry Creation Hatchery Center (NICHe), Tohoku University, 6-6-10 Aoba, Aramaki, Aoba-ku, Sendai 980-8579, Miyagi (Japan); Institute of Physics, AS CR, Cukrovarnická 10, 162 53 Prague (Czech Republic); Yokota, Yuui; Kamada, Kei [New Industry Creation Hatchery Center (NICHe), Tohoku University, 6-6-10 Aoba, Aramaki, Aoba-ku, Sendai 980-8579, Miyagi (Japan); Yoshikawa, Akira [Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Miyagi (Japan); New Industry Creation Hatchery Center (NICHe), Tohoku University, 6-6-10 Aoba, Aramaki, Aoba-ku, Sendai 980-8579, Miyagi (Japan); C and A Corporation, 6-6-40 Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8577 (Japan)

    2015-02-01

    Temperature dependence of scintillation properties was investigated for (Ce{sub 0.01}, Gd{sub 0.90}, La{sub 0.09}){sub 2}Si{sub 2}O{sub 7} grown by floating zone method. The light output over 35,000 photons/MeV was found constant in the temperature range from 0 °C to 150 °C. In addition, FWHM energy resolution of Ce:La-GPS (roughly 7–8%) at 662 keV remained constant up to 100 °C. Thus, this crystal can be applied to oil well logging or other radiation detection application at high temperature conditions.

  17. Laser micromachining of cadmium tungstate scintillator for high energy X-ray imaging

    Science.gov (United States)

    Richards, Sion Andreas

    Pulsed laser ablation has been investigated as a method for the creation of thick segmented scintillator arrays for high-energy X-ray radiography. Thick scintillators are needed to improve the X-ray absorption at high energies, while segmentation is required for spatial resolution. Monte-Carlo simulations predicted that reflections at the inter-segment walls were the greatest source of loss of scintillation photons. As a result of this, fine pitched arrays would be inefficient as the number of reflections would be significantly higher than in large pitch arrays. Nanosecond and femtosecond pulsed laser ablation was investigated as a method to segment cadmium tungstate (CdWO_4). The effect of laser parameters on the ablation mechanisms, laser induced material changes and debris produced were investigated using optical and electron microscopy, energy dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy for both types of lasers. It was determined that nanosecond ablation was unsuitable due to the large amount of cracking and a heat affected zone created during the ablation process. Femtosecond pulsed laser ablation was found to induce less damage. The optimised laser parameters for a 1028 nm laser was found to be a pulse energy of 54 μJ corresponding to a fluence of 5.3 J cm. -2 a pulse duration of 190 fs, a repetition rate of 78.3 kHz and a laser scan speed of 707 mm s. -1 achieving a normalised pulse overlap of 0.8. A serpentine scan pattern was found to minimise damage caused by anisotropic thermal expansion. Femtosecond pulsed ablation was also found to create a layer of tungsten and cadmium sub-oxides on the surface of the crystals. The CdWO_4 could be cleaned by immersing the CdWO_4 in ammonium hydroxide at 45°C for 15 minutes. However, XPS indicated that the ammonium hydroxide formed a thin layer of CdCO_3 and Cd(OH)_2 on the surface. Prototype arrays were shown to be able to resolve features as small as 0.5 mm using keV energy X-rays. The most

  18. Investigating the effect of K-characteristic radiation on the performance of nuclear medicine scintillators by Monte Carlo methods

    International Nuclear Information System (INIS)

    Liaparinos, Panagiotis; Kandarakis, Ioannis; Cavouras, Dionisis; Delis, Harry; Panayiotakis, George

    2006-01-01

    The aim of this study was to evaluate the effect of K-characteristic radiation on the performance of scintillator crystals incorporated in nuclear medicine detectors (LSO, BGO, GSO). K-characteristic radiation is produced within materials of at least one high atomic number element (e.g. Lu, Gd, Bi). This radiation may either be reabsorbed or it may escape the scintillator. In both cases the light emission efficiency of the scintillator may be affected resulting in either spatial or energy resolution degradation. A computational program, based on Monte Carlo methods, was developed in order to simulate the transport of K-characteristic radiation within the most commonly used scintillator materials. Crystal thickness was allowed to vary from 0.5 up to 15 mm. A monoenergetic pencil beam, with energy varying from 0.60 to 0.511 MeV was considered to fall on the center of the crystal surface. The dominant γ-ray interactions (elastic and inelastic scattering and photoelectric absorption) were taken into account in the simulation. Results showed that, depending on crystal thickness, incident photon energy and scintillator's intrinsic properties (L or K-fluorescence yield, effective atomic number and density), the scintillator's emission efficiency may be significantly reduced and affect spatial or energy resolution

  19. Effects of surface coatings on the light collection in plastic scintillators used for radioxenon detection

    International Nuclear Information System (INIS)

    Bläckberg, L; Klintenberg, M; Sjöstrand, H; Ringbom, A

    2012-01-01

    Atomic layer deposition coatings are under investigation to reduce the diffusion of radioxenon into plastic scintillators. This paper investigates the impact of such surface coating on the light collection efficiency in a cylindrical geometry. A high and uniform light collection efficiency is important to preserve detector resolution. Monte Carlo simulations and measurements have been carried out to study the influence of coating thickness, refractive index and surface quality. It was found that it is important to achieve a smooth coating and good optical match between the refractive indices of the coating and the plastic scintillator. Taking into account these considerations, the detector under study could be coated without a significant degradation of its resolution.

  20. Scintillation γ spectrography. Physical principles. Apparatus. Operation

    International Nuclear Information System (INIS)

    Julliot, C.

    1960-01-01

    The scintillation detector forms the main part of the instrument used, the electronic unit presenting the results produced. After a brief description of the process of γ photon absorption in the material, the particular case of NaI (T1), the scintillator used, is examined. The intensity of the scintillation caused by γ ray absorption and the characteristics of the photomultiplier play a determining part in the energy resolution of the instrument. For the γ recording spectrograph, we show to what extent the technique for using the electronic unit can modify the results. A detailed description is given of the activity measurement of a γ-emitting radioelement by the spectrographic method. (author) [fr

  1. Memory effect, resolution, and efficiency measurements of an Al{sub 2}O{sub 3} coated plastic scintillator used for radioxenon detection

    Energy Technology Data Exchange (ETDEWEB)

    Bläckberg, L., E-mail: lisa.blackberg@physics.uu.se [Department of Physics and Astronomy, Uppsala University, Box 516, SE-75120 Uppsala (Sweden); Fritioff, T.; Mårtensson, L.; Nielsen, F.; Ringbom, A. [Division of Defence and Security Systems, Swedish Defence Research Agency (FOI), SE-17290 Stockholm (Sweden); Sjöstrand, H.; Klintenberg, M. [Department of Physics and Astronomy, Uppsala University, Box 516, SE-75120 Uppsala (Sweden)

    2013-06-21

    A cylindrical plastic scintillator cell, used for radioxenon monitoring within the verification regime of the Comprehensive Nuclear-Test-Ban Treaty, has been coated with 425 nm Al{sub 2}O{sub 3} using low temperature Atomic Layer Deposition, and its performance has been evaluated. The motivation is to reduce the memory effect caused by radioxenon diffusing into the plastic scintillator material during measurements, resulting in an elevated detection limit. Measurements with the coated detector show both energy resolution and efficiency comparable to uncoated detectors, and a memory effect reduction of a factor of 1000. Provided that the quality of the detector is maintained for a longer period of time, Al{sub 2}O{sub 3} coatings are believed to be a viable solution to the memory effect problem in question.

  2. High luminosity operation of large solid angle scintillator arrays in Jefferson Lab Hall A

    International Nuclear Information System (INIS)

    Ran Shneor

    2003-01-01

    This thesis describes selected aspects of high luminosity operation of large solid angle scintillator arrays in Hall A of the CEBAF (Central Electron Beam Accelerator Facility) at TJNAF (Thomas Jefferson National Accelerator Facility ). CEBAF is a high current, high duty factor electron accelerator with a maximum beam energy of about 6 GeV and a maximum current of 200 (micro)A. Operating large solid angle scintillator arrays in high luminosity environment presents several problems such as high singles rates, low signal to noise ratios and shielding requirements. To demonstrate the need for large solid angle and momentum acceptance detectors as a third arm in Hall A, we will give a brief overview of the physics motivating five approved experiments, which utilize scintillator arrays. We will then focus on the design and assembly of these scintillator arrays, with special focus on the two new detector packages built for the Short Range Correlation experiment E01-015. This thesis also contains the description and results of different tests and calibrations which where conducted for these arrays. We also present the description of a number of tests which were done in order to estimate the singles rates, data reconstruction, filtering techniques and shielding required for these counters

  3. Lanthanum halide scintillators: Properties and applications

    International Nuclear Information System (INIS)

    Iltis, Alain; Mayhugh, M.R.; Menge, P.; Rozsa, C.M.; Selles, O.; Solovyev, V.

    2006-01-01

    BrilLanCe[reg]-350 and BrilLanCe[reg]-380, Saint-Gobain Crystals' trade-names for LaCl 3 :Ce and LaBr 3 :Ce are being brought to market under exclusive license to Delft and Bern Universities. We are reporting the properties of crystals produced with commercially viable processes and find they match others' observations. These scintillators are bright (60,000 photons/MeV for LaBr 3 :Ce) and have very linear response, a combination that leads to very good energy resolution ( 3 :Ce). The materials also have fast scintillation decay times ( 3 :Ce). These excellent properties are retained at high temperature with only moderate light loss ( 138 and Ac 227 , the latter having been substantially reduced in recent processing. BrilLanCe[reg]-350 is now available in detectors up to 51 mm diameter while 38 mm diameter is available for BrilLanCe[reg]-380. Larger sizes are expected

  4. Study of polystyrene scintillators-WLS fiber elements and scintillating tile-WLS prototypes for New CHOD detector of CERN NA-62 experiment

    CERN Document Server

    Semenov, Vitaliy; Gorin, Aleksandr; Khudyakov, Aleksey; Rykalin, Vladimir; Yushchenko, Oleg

    2016-01-01

    We measured the light output and the time resolution of few sets comprised of polystyrene scintillator and wavelength shifting (WLS) fibers as readout. The samples of different thickness (7-30 mm) have been made in the shape of bricks and plates with the areas of 25×80, 108×134 and 108×268 of mm2. In addition to samples of “ordinary” scintillator with additions of 2% p- Terphenyl + 0.05% POPOP, the rapid ultraviolet scintillator with single 2% additive PBD was tested. For the light collection WLS-fibers BCF92, Y11 and scintillation fiber SCSF-78M as reemitting were checked. The fibers were glued into the grooves on the front surface of scintillators. As the photo detectors silicon photomultipliers (SiPM) produced by CPTA (Russia) and SensL (Ireland) were used. It is shown that the dependence of light output on the thickness of scintillator is nonlinear and close to the square root function, which is also confirmed by the calculations carried out by Monte Carlo. The measured value of a light output make...

  5. FLARES: A flexible scintillation light apparatus for rare event searches

    Energy Technology Data Exchange (ETDEWEB)

    Sisti, M., E-mail: monica.sisti@mib.infn.it [Dipartimento di Fisica, Università di Milano-Bicocca and INFN – Sezione di Milano-Bicocca, Milano (Italy); Baldazzi, G. [Dipartimento di Fisica e Astronomia, Università di Bologna and INFN – Sezione di Bologna, Bologna (Italy); Bonvicini, V. [INFN – Sezione di Trieste, Trieste (Italy); Campana, R. [INAF/IASF and INFN – Sezione di Bologna, Bologna (Italy); Capelli, S. [Dipartimento di Fisica, Università di Milano-Bicocca and INFN – Sezione di Milano-Bicocca, Milano (Italy); Evangelista, Y.; Feroci, M. [INAF/IASF and INFN – Sezione di Roma2, Roma (Italy); Fuschino, F. [Dipartimento di Fisica e Astronomia, Università di Bologna and INFN – Sezione di Bologna, Bologna (Italy); INAF/IASF and INFN – Sezione di Bologna, Bologna (Italy); Gironi, L. [Dipartimento di Fisica, Università di Milano-Bicocca and INFN – Sezione di Milano-Bicocca, Milano (Italy); Labanti, C.; Marisaldi, M. [INAF/IASF and INFN – Sezione di Bologna, Bologna (Italy); Previtali, E. [Dipartimento di Fisica, Università di Milano-Bicocca and INFN – Sezione di Milano-Bicocca, Milano (Italy); Rignanese, L. [Dipartimento di Fisica e Astronomia, Università di Bologna and INFN – Sezione di Bologna, Bologna (Italy); Rachevsky, A. [INFN – Sezione di Trieste, Trieste (Italy); Vacchi, A. [INFN – Sezione di Trieste, Trieste (Italy); Dipartimento di Matematica e Informatica, Università di Udine, Udine (Italy); Zampa, G.; Zampa, N. [INFN – Sezione di Trieste, Trieste (Italy); Zuffa, M. [Dipartimento di Fisica e Astronomia, Università di Bologna and INFN – Sezione di Bologna, Bologna (Italy)

    2016-07-11

    FLARES is a project for an innovative detector technology to be applied to rare event searches, and in particular to neutrinoless double beta decay experiments. Its novelty is the enhancement and optimization of the collection of the scintillation light emitted by ultra-pure crystals through the use of arrays of high performance silicon photodetectors cooled to 120 K. This would provide scintillation detectors with 1% level energy resolution, with the advantages of a technology offering relatively simple low cost mass scalability and powerful background reduction handles, as requested by future neutrinoless double beta decay experimental programs. The performances of a first production of matrices of Silicon Drift Detectors are presented and discussed in this paper.

  6. FLARES: A flexible scintillation light apparatus for rare event searches

    International Nuclear Information System (INIS)

    Sisti, M.; Baldazzi, G.; Bonvicini, V.; Campana, R.; Capelli, S.; Evangelista, Y.; Feroci, M.; Fuschino, F.; Gironi, L.; Labanti, C.; Marisaldi, M.; Previtali, E.; Rignanese, L.; Rachevsky, A.; Vacchi, A.; Zampa, G.; Zampa, N.; Zuffa, M.

    2016-01-01

    FLARES is a project for an innovative detector technology to be applied to rare event searches, and in particular to neutrinoless double beta decay experiments. Its novelty is the enhancement and optimization of the collection of the scintillation light emitted by ultra-pure crystals through the use of arrays of high performance silicon photodetectors cooled to 120 K. This would provide scintillation detectors with 1% level energy resolution, with the advantages of a technology offering relatively simple low cost mass scalability and powerful background reduction handles, as requested by future neutrinoless double beta decay experimental programs. The performances of a first production of matrices of Silicon Drift Detectors are presented and discussed in this paper.

  7. Direct and indirect signal detection of 122 keV photons with a novel detector combining a pnCCD and a CsI(Tl) scintillator

    Energy Technology Data Exchange (ETDEWEB)

    Schlosser, D.M., E-mail: dieter.schlosser@pnsensor.de [PNSensor GmbH, Sckellstraße 3, 81667 München (Germany); Huth, M.; Hartmann, R. [PNSensor GmbH, Sckellstraße 3, 81667 München (Germany); Abboud, A.; Send, S. [Universität Siegen, Walter-Flex-Straße 3, 57072 Siegen (Germany); Conka-Nurdan, T. [Türkisch-Deutsche Universität, Sakinkaya Cad. 86, Beykoz, 34820 Istanbul (Turkey); Shokr, M.; Pietsch, U. [Universität Siegen, Walter-Flex-Straße 3, 57072 Siegen (Germany); Strüder, L. [PNSensor GmbH, Sckellstraße 3, 81667 München (Germany); Universität Siegen, Walter-Flex-Straße 3, 57072 Siegen (Germany)

    2016-01-01

    By combining a low noise fully depleted pnCCD detector with a CsI(Tl) scintillator, an energy-dispersive area detector can be realized with a high quantum efficiency (QE) in the range from below 1 keV to above 100 keV. In direct detection mode the pnCCD exhibits a relative energy resolution of 1% at 122 keV and spatial resolution of less than 75 µm, the pixel size of the pnCCD. In the indirect detection mode, i.e. conversion of the incoming X-rays in the scintillator, the measured energy resolution was about 9–13% at 122 keV, depending on the depth of interaction in the scintillator, while the position resolution, extracted with the help of simulations, was 30 µm only. We show simulated data for incident photons of 122 keV and compare the various interaction processes and relevant physical parameters to experimental results obtained with a radioactive {sup 57}Co source. - Highlights: • Position and energy resolving pnCCD+CsI(Tl) detector for energies from 1-150 keV • Detection in the pnCCD (122keV): 1% energy and <75µm spatial resolution • Detection in the scintillator (122keV): 9-12% energy and ~30µm spatial resolution.

  8. Luminescence rise time in self-activated PbWO4 and Ce-doped Gd3Al2Ga3O12 scintillation crystals

    CERN Document Server

    E. Auffray; A. Borisevich; V. Gulbinas; A. Fedorov; M. Korjik; M.T. Lucchini; V. Mechinsky; S. Nargelas; E. Songaila; G. Tamulaitis; A. Vaitkevičius; S. Zazubovich

    2016-01-01

    The time resolution of scintillation detectors of ionizing radiation is one of the key parameters sought for in the current and future high-energy physics experiments. This study is encouraged by the necessity to find novel detection methods enabling a sub-10-ps time resolution in scintillation detectors and is focused on the exploitation of fast luminescence rise front. Time-resolved photoluminescence (PL) spectroscopy and thermally stimulated luminescence techniques have been used to study two promising scintillators: self-activated lead tungstate (PWO, PbWO4) and Ce-doped gadolinium aluminum gallium garnet (GAGG, Gd3Al2Ga3O12). A sub-picosecond PL rise time is observed in PWO, while longer processes in the PL response in GAGG:Ce are detected and studied. The mechanisms responsible for the PL rise time in self-activated and doped scintillators are under discussion.

  9. Performance study of Philips digital silicon photomultiplier coupled to scintillating crystals

    CERN Document Server

    Liu, Z.; Auffray, E.; Lecoq, P.; Paganoni, M.

    2016-01-01

    Silicon photomultipliers (SiPMs) and scintillators are often arranged in the shape of arrays in Positron Emission Tomography (PET) systems. Digital SiPMs provide signal readout in single photon avalanche diode (SPAD) level. From the photon count rate measurement of each SPAD cell of digital SiPM, we found that the output scintillating photons distribute in an area larger than the scintillator physical coupling area. Taking advantage of the possibility to enable/disable individual cells of the digital SiPM, a group of Lutetium-yttrium oxyorthosilicate (LYSO) crystals with different dimensions coupled to a digital SiPM was used to study the influence of using different SiPM active area on the number of photons detected, energy resolution and coincidence time resolution (CTR). For the same crystal coupled to the digital SiPM, the larger the active area of digital SiPM, the higher the number of photons detected. The larger active area of the digital SiPM also results in a better energy resolution after saturation...

  10. Measurement methods for several properties of scintillator

    International Nuclear Information System (INIS)

    Luo Fengqun; Ji Changsong

    1998-01-01

    The current paper describes the experimental measurement methods for the relative light output, the relative energy conversion efficiency, the intrinsic amplitude resolution and the detection efficiency of the scintillators and their temperature effects

  11. Gammastic: towards a pseudo-gamma spectrometry in plastic scintillators

    International Nuclear Information System (INIS)

    Hamel, Matthieu; Dehe-Pittance, Chrystele; Coulon, Romain; Carrel, Frederick; Pillot, Philippe; Barat, Eric; Dautremer, Thomas; Montagu, Thierry; Normand, Stephane

    2013-06-01

    War against CBRN-E threats needs to continuously develop sensors with improved detection efficiency. More particularly, this topic concerns the NR controls for homeland security. A first analysis requires indeed a fast gamma spectrometry so as to detect potential special nuclear materials (SNM). To this aim, plastic scintillators could represent the best alternative for the production of large-scale, low-cost radiation portal monitors to be deployed on boarders, tolls, etc. Although they are known to be highly sensitive to gamma rays, due to their poor resolution, information relative to the nature of the SNM is tricky. Thus, only the Compton edge is obtained after interaction, and no information of the photoelectric peak is observed. This project concerns new developments on a possible pseudo-gamma spectrometry performed with plastic scintillators. This project is articulated on a combination of two developments: - The design of new materials most suitable for recovering the photoelectric peak after gamma interaction with the scintillator. This work concerns mainly plastic scintillators loading with heavy elements, such as lead or bismuth. - The analysis of the resulting signal with smart algorithms. This work is thus a pluri-disciplinary work performed at CEA LIST and embeds 4 main disciplines: MCNPX simulations (simulated spectra), chemistry of materials (preparation of various plastic scintillators with different properties), instrumentation (lab experiments) and smart algorithms. Really impressive results were obtained with the unfolding of simulated spectra at various energies (from 241 Am to 60 Co) and an innovative approach was proposed to counter-balance the quenching effect of luminescence by heavy elements in plastic scintillators. (authors)

  12. Development of a scintillating-fibre detector for fast topological triggers in high-luminosity particle physics experiments

    CERN Document Server

    Agoritsas, V; Bing, O; Bravar, A; Cardini, A; Dreossi, D; Drevenak, R; Finger, M H; Flaminio, Vincenzo; Di Girolamo, B; Gorin, A; Kulikov, A; Kuroda, K; Manuilov, I V; Okada, K; Önel, Y M; Penzo, Aldo L; Rapin, D; Rappazzo, G F; Riazantsev, A V; Rykalin, V I; Slunecka, M; Takeutchi, F; Trusov, S V; Yoshida, T

    1998-01-01

    In the framework of the RD-17 project at CERN extensive work is in progresson the development of scintillating-fibre detectors using position-sensitive photomultipliers. With o.5 mm diameter fibres as spatial resolution of about 125 µm was obtained with a detection efficiency higher than 95%. The time resolution of the detector is about 600 ps, and the track position is properly digitized in real time in less than 10 ns by a peak sensing circuit. A simulation, based on experimental data, was also performed to compare different types of front-end electronics.

  13. Simulation of optical configurations and signal processing methods in Anger-type neutron-position scintillation detector

    International Nuclear Information System (INIS)

    Roche, C.T.; Strauss, M.G.; Brenner, R.

    1984-01-01

    The spatial linearity and resolution of Anger-type neutron-position scintillation detectors are studied using a semi-empirical model. Detector optics with either an air gap or optical grease between the scintillator and the dispersive light guide are considered. Three signal processing methods which truncate signals from PMT's distant from the scintillation are compared with the linear resistive weighting method. Air gap optics yields a 15% improvement in spatial resolution and 50% reduction in differential and integral nonlinearity relative to grease coupled optics, using linear processing. Using signal truncation instead of linear processing improves the resolution 15-20% for the air gap and 20-30% for the grease coupling case. Thus, the initial discrepancy in the resolution between the two optics nearly vanished, however the linearity of the grease coupled system is still significantly poorer

  14. 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

  15. Charged particle scintillation mass spectrometer

    International Nuclear Information System (INIS)

    Baranov, P.S.; Zhuravlev, E.E.; Nafikov, A.A.; Osadchi , A.I.; Raevskij, V.G.; Smirnov, P.A.; Cherepnya, S.N.; Yanulis, Yu.P.

    1982-01-01

    A scintillation mass-spectrometer for charged particle identification by the measured values of time-of-flight and energy operating on line with the D-116 computer is described. Original time detectors with 100x100x2 mm 3 and 200x2 mm 2 scintillators located on the 1- or 2 m path length are used in the spectrometer. The 200x200x200 mm 3 scintillation unit is used as a E-counter. Time-of-flight spectra of the detected particles on the 2 m path length obtained in spectrometer test in the beam of charged particles escaping from the carbon target at the angle of 130 deg under 1.2 GeV bremsstrahlung beam of the ''Pakhra'' PIAS synchrotron are presented. Proton and deuteron energy spectra as well as mass spectrum of all the particles detected by the spectrometer are given. Mass resolution obtained on the 2 m path length for π-mesons is +-25%, for protons is +-5%, for deuterons is +-3%

  16. An integrated photosensor readout for gas proportional scintillation counters

    International Nuclear Information System (INIS)

    Lopes, J.A.M.; Santos, J.M.F. dos; Conde, C.A.N.

    1996-01-01

    A xenon gas proportional scintillation counter has been instrumented with a novel photosensor that replaces the photomultiplier tube normally used to detect the VUV secondary scintillation light. In this implementation, the collection grid of a planar gas proportional scintillation counter also functions as a multiwire proportional chamber to amplify and detect the photoelectrons emitted by a reflective CsI photocathode in direct contact with the xenon gas. This integrated concept combines greater simplicity, compactness, and ruggedness (no optical window is used) with low power consumption. An energy resolution of 12% was obtained for 59.6 keV x-rays

  17. Plastic scintillators with {beta}-diketone Eu complexes for high ionizing radiation detection

    Energy Technology Data Exchange (ETDEWEB)

    Adadurov, A.F., E-mail: adadurov@isma.kharkov.ua [Institute for Scintillating Materials, NAN of Ukraine, Lenin Avenue 60, 61001 Kharkov (Ukraine); Zhmurin, P.N.; Lebedev, V.N.; Kovalenko, V.N. [Institute for Scintillating Materials, NAN of Ukraine, Lenin Avenue 60, 61001 Kharkov (Ukraine)

    2011-10-15

    Luminescent and scintillation properties of polystyrene-based plastic scintillators with {beta}-diketone Eu complexes are investigated. A scintillator with dibenzoylmethane Eu complex containing two phenyl groups demonstrates the maximum scintillating efficiency. It is shown that plastic scintillators efficiency is dramatically decreased if {beta}-diketone derivatives contain no phenyl groups as substituents. This fact can be explained by exciplex mechanism of energy transfer from a matrix to Eu complex. - Highlights: > Fluorescent properties of polystyrene scintillators with {beta}-diketone complexes of Eu were studied. > Scintillating efficiency is increased with the number of phenyl groups in Eu complex. > This is related to exciplex mechanism of energy transfer from a polymer matrix to Eu complex.

  18. High resolution study of the inclusive production of massive muon pairs by intense pion beams

    CERN Multimedia

    2002-01-01

    This experiment measures with high resolution and large acceptance the inclusive production of massive muon pairs with the intense pion beam (up to $10^{10} \\pi/$pulse) in the experimental hall ECN3. The experiment explores extended M$^{2}$/s, x and transverse momentum ranges. The study of the departures of the lepton-pair production cross- section from scaling constitutes a good test of QCD ideas; in the framework of the 'Drell-Yan' process, the experiment allows a detailed study of the pion parton distribution functions. The detector consists of a beam dump, a pulsed toroidal a magnet, MWPC's and scintillator hodoscopes. Its $\\sim 2$% mass resolution at 10 GeV is adequate for the substraction of resonances in the high-mass region.

  19. GPS phase scintillation at high latitudes during the geomagnetic storm of 17-18 March 2015

    DEFF Research Database (Denmark)

    Prikryl, P.; Ghoddousi-Fard, R.; Weygand, J. M.

    2016-01-01

    The geomagnetic storm of 17–18 March 2015 was caused by the impacts of a coronal mass ejection and a high-speed plasma stream from a coronal hole. The high-latitude ionosphere dynamics is studied using arrays of ground-based instruments including GPS receivers, HF radars, ionosondes, riometers......, and magnetometers. The phase scintillation index is computed for signals sampled at a rate of up to 100 Hz by specialized GPS scintillation receivers supplemented by the phase scintillation proxy index obtained from geodetic-quality GPS data sampled at 1 Hz. In the context of solar wind coupling...... to the magnetosphere-ionosphere system, it is shown that GPS phase scintillation is primarily enhanced in the cusp, the tongue of ionization that is broken into patches drawn into the polar cap from the dayside storm-enhanced plasma density, and in the auroral oval. In this paper we examine the relation between...

  20. Ionization and scintillation signals produced by relativistic La ions in liquid argon

    Energy Technology Data Exchange (ETDEWEB)

    Crawford, H J; Doke, T; Hitachi, H; Kikuchi, J; Lindstrom, P J; Masuda, K; Shibamura, E; Nagamiya, S

    1987-04-15

    We have observed simultaneously the ionization and scintillation signals produced by relativistic La ions in liquid argon. The two signals are highly correlated and the sums of these signals are constant with the standard deviation of 1.2% over the range of the electric field from 0 to 7.5 kV/cm. The ratio of the sum signals expressed in unit of the number of species to the value N/sub i/ + N/sub ex/ is close to unity where N/sub i/ and N/sub ex/ are the numbers of ion pairs and excitons, respectively, produced by La ions in liquid argon. The pulse height resolution of the sum of the signals is better than that of ionization or scintillation alone. Almost no quenching is found in the scintillation signal from relativistic La ions when compared to signals from lighter ions.

  1. Design of a fusion reaction-history measurement system with high temporal resolution

    International Nuclear Information System (INIS)

    Peng Xiaoshi; Wang Feng; Liu Shenye; Jiang Xiaohua; Tang Qi

    2010-01-01

    In order to accurately measure the history of fusion reaction for experimental study of inertial confinement fusion, we advance the design of a fusion reaction-history measurement system with high temporal resolution. The diagnostic system is composed of plastic scintillator and nose cone, an optical imaging system and the system of optic streak camera. Analyzing the capability of the system indicated that the instrument measured fusion reaction history at temporal resolution as low as 55ps and 40ps correspond to 2.45MeV DD neutrons and 14.03MeV DT neutrons. The instrument is able to measure the fusion reaction history at yields 1.5 x 10 9 DD neutrons, about 4 x 10 8 DT neutrons are required for a similar quality signal. (authors)

  2. Scintillator material. Szintillatormaterial

    Energy Technology Data Exchange (ETDEWEB)

    Siegmund, M; Bendig, J; Regenstein, W

    1987-11-25

    A scintillator material for detection and quantitative determination of ionizing radiation is discussed consisting of an acridone dissolved in a fluid or solid medium. Solvent mixtures with at least one protogenic component or polymers and copolymers are used. The scintillator material is distinguished by an excellent stability at high energy doses.

  3. Performance of a scintillating fibres semiprojective electromagnetic calorimeter

    International Nuclear Information System (INIS)

    Bertino, M.; Bini, C.; De Zorzi, G.; Diambrini Palazzi, G.; Di Cosimo, G.; Di Domenico, A.; Garufi, F.; Gauzzi, P.; Zanello, D.

    1995-01-01

    A highly segmented scintillating fibres/lead electromagnetic calorimeter has been tested. Each calorimeter module has semiprojective geometry and is shaped as a wedge with an angle of (0.82) . The fibres are however parallel to the wedge axis and the two small lateral regions are not fibre-instrumented. This simple and cheap approach to a projective geometry allows to achieve still good energy and space resolution. Results with electrons in the range 10-100 GeV are presented. ((orig.))

  4. Scintillating fiber detector performance, detector geometries, trigger, and electronics issues for scintillating fiber tracking

    International Nuclear Information System (INIS)

    Baumbaugh, A.E.

    1994-06-01

    Scintillating Fiber tracking technology has made great advances and has demonstrated great potential for high speed charged particle tracking and triggering. The small detector sizes and fast scintillation fluors available make them very promising for use at high luminosity experiments at today's and tomorrow's colliding and fixed target experiments where high rate capability is essential. This talk will discuss the current state of Scintillating fiber performance and current Visual Light Photon Counter (VLPC) characteristics. The primary topic will be some of the system design and integration issues which should be considered by anyone attempting to design a scintillating fiber tracking system which includes a high speed tracking trigger. Design. constraints placed upon the detector system by the electronics and mechanical sub-systems will be discussed. Seemingly simple and unrelated decisions can have far reaching effects on overall system performance. SDC and DO example system designs will be discussed

  5. The measurement of the presampled MTF of a high spatial resolution neutron imaging system

    International Nuclear Information System (INIS)

    Cao, Raymond Lei; Biegalski, Steven R.

    2007-01-01

    A high spatial resolution neutron imaging device was developed at the Mark II TRIGA reactor at University of Texas at Austin. As the modulation transfer function (MTF) is recognized as a well-established parameter for evaluation of imaging system resolution, the aliasing associated with digital sampling adds complexity to its measurement. Aliasing is especially problematic when using a high spatial resolution micro-channel plate (MCP) neutron detector that has a pixel grid size similar to that of a CCD array. To compensate for the aliasing an angulated edge method was used to evaluate the neutron imaging facility, overcoming aliasing by obtaining an oversampled edge spread function (ESF). Baseline correction was applied to the ESF to remove the noticeable trends and the LSF was multiplied by Hann window to obtain a smoothed version of presampled MTF. The computing procedure is confirmed by visual inspection of a testing phantom; in addition, it is confirmed by comparison to the MTF measurement of a scintillation screen with a known MTF curve

  6. Systematic studies of small scintillators for new sampling calorimeter

    International Nuclear Information System (INIS)

    Jacosalem, E.P.; Sanchez, A.L.C.; Bacala, A.M.; Iba, S.; Nakajima, N.; Ono, H.; Miyata, H.

    2007-01-01

    A new sampling calorimeter using very thin scintillators and the multi-pixel photon counter (MPPC) has been proposed to produce better position resolution for the international linear collider (ILC) experiment. As part of this R and D study, small plastic scintillators of different sizes, thickness and wrapping reflectors are systematically studied. The scintillation light due to beta rays from a collimated 90 Sr source are collected from the scintillator by wavelength-shifting (WLS) fiber and converted into electrical signals at the PMT. The wrapped scintillator that gives the best light yield is determined by comparing the measured pulse height of each 10 x 40 x 2 mm strip scintillator covered with 3M reflective mirror film, teflon, white paint, black tape, gold, aluminum and white paint+teflon. The pulse height dependence on position, length and thickness of the 3M reflective mirror film and teflon wrapped scintillators are measured. Results show that the 3M radiant mirror film-wrapped scintillator has the greatest light yield with an average of 9.2 photoelectrons. It is observed that light yield slightly increases with scintillator length, but increases to about 100% when WLS fiber diameter is increased from 1.0 mm to 1.6 mm. The position dependence measurement along the strip scintillator showed the uniformity of light transmission from the sensor to the PMT. A dip across the strip is observed which is 40% of the maximum pulse height. The block type scintillator pulse height, on the other hand, is found to be almost proportional to scintillator thickness. (author)

  7. Discrimination of Naturally Occurring Radioactive Material in Plastic Scintillator Material

    International Nuclear Information System (INIS)

    Ely, James H.; Kouzes, Richard T.; Geelhood, Bruce D.; Schweppe, John E.; Warner, Ray A.

    2003-01-01

    Plastic scintillator material is used in many applications for the detection of gamma-rays from radioactive material, primarily due to the sensitivity per unit cost compared to other detection materials. However, the resolution and lack of full-energy peaks in the plastic scintillator material prohibits detailed spectroscopy. Therefore, other materials such as doped sodium iodide are used for spectroscopic applications. The limited spectroscopic information can however be exploited in plastic scintillator materials to provide some discrimination. The discrimination between man-made and naturally occurring sources would be useful in reducing alarm screening for radiation detection applications which target man-made sources. The results of applying the limited energy information from plastic scintillator material for radiation portal monitors are discussed.

  8. Plastic scintillators with β-diketone Eu complexes for high ionizing radiation detection

    International Nuclear Information System (INIS)

    Adadurov, A.F.; Zhmurin, P.N.; Lebedev, V.N.; Kovalenko, V.N.

    2011-01-01

    Luminescent and scintillation properties of polystyrene-based plastic scintillators with β-diketone Eu complexes are investigated. A scintillator with dibenzoylmethane Eu complex containing two phenyl groups demonstrates the maximum scintillating efficiency. It is shown that plastic scintillators efficiency is dramatically decreased if β-diketone derivatives contain no phenyl groups as substituents. This fact can be explained by exciplex mechanism of energy transfer from a matrix to Eu complex. - Highlights: → Fluorescent properties of polystyrene scintillators with β-diketone complexes of Eu were studied. → Scintillating efficiency is increased with the number of phenyl groups in Eu complex. → This is related to exciplex mechanism of energy transfer from a polymer matrix to Eu complex.

  9. High Resolution Gamma Ray Spectroscopy at MHz Counting Rates With LaBr3 Scintillators for Fusion Plasma Applications

    Science.gov (United States)

    Nocente, M.; Tardocchi, M.; Olariu, A.; Olariu, S.; Pereira, R. C.; Chugunov, I. N.; Fernandes, A.; Gin, D. B.; Grosso, G.; Kiptily, V. G.; Neto, A.; Shevelev, A. E.; Silva, M.; Sousa, J.; Gorini, G.

    2013-04-01

    High resolution γ-ray spectroscopy measurements at MHz counting rates were carried out at nuclear accelerators, combining a LaBr 3(Ce) detector with dedicated hardware and software solutions based on digitization and off-line analysis. Spectra were measured at counting rates up to 4 MHz, with little or no degradation of the energy resolution, adopting a pile up rejection algorithm. The reported results represent a step forward towards the final goal of high resolution γ-ray spectroscopy measurements on a burning plasma device.

  10. Electron response of some low-Z scintillators in wide energy range

    International Nuclear Information System (INIS)

    Swiderski, L; Marcinkowski, R; Moszynski, M; Czarnacki, W; Szawlowski, M; Szczesniak, T; Pausch, G; Plettner, C; Roemer, K

    2012-01-01

    Light yield nonproportionality and the intrinsic resolution of some low atomic number scintillators were studied by means of the Wide Angle Compton Coincidence (WACC) technique. The plastic and liquid scintillator response to Compton electrons was measured in the energy range of 10 keV up to 4 MeV, whereas a CaF 2 :Eu sample was scanned from 3 keV up to 1 MeV. The nonproportionality of the CaF 2 :Eu light yield has characteristics typical for inorganic scintillators of the multivalent halides group, whereas tested organic scintillators show steeply increasing nonproportionality without saturation point. This is in contrast to the behavior of all known inorganic scintillators having their nonproportionality curves at saturation above energies between tens and several hundred keV.

  11. Electron response of some low-Z scintillators in wide energy range

    Science.gov (United States)

    Swiderski, L.; Marcinkowski, R.; Moszynski, M.; Czarnacki, W.; Szawlowski, M.; Szczesniak, T.; Pausch, G.; Plettner, C.; Roemer, K.

    2012-06-01

    Light yield nonproportionality and the intrinsic resolution of some low atomic number scintillators were studied by means of the Wide Angle Compton Coincidence (WACC) technique. The plastic and liquid scintillator response to Compton electrons was measured in the energy range of 10 keV up to 4 MeV, whereas a CaF2:Eu sample was scanned from 3 keV up to 1 MeV. The nonproportionality of the CaF2:Eu light yield has characteristics typical for inorganic scintillators of the multivalent halides group, whereas tested organic scintillators show steeply increasing nonproportionality without saturation point. This is in contrast to the behavior of all known inorganic scintillators having their nonproportionality curves at saturation above energies between tens and several hundred keV.

  12. Design and Prototyping of a High Granularity Scintillator Calorimeter

    International Nuclear Information System (INIS)

    Zutshi, Vishnu

    2016-01-01

    A novel approach for constructing fine-granularity scintillator calorimeters, based on the concept of an Integrated Readout Layer (IRL) was developed. The IRL consists of a printed circuit board inside the detector which supports the directly-coupled scintillator tiles, connects to the surface-mount SiPMs and carries the necessary front-end electronics and signal/bias traces. Prototype IRLs using this concept were designed, prototyped and successfully exposed to test beams. Concepts and implementations of an IRL carried out with funds associated with this contract promise to result in the next generation of scintillator calorimeters.

  13. Design and Prototyping of a High Granularity Scintillator Calorimeter

    Energy Technology Data Exchange (ETDEWEB)

    Zutshi, Vishnu [Northern Illinois Univ., DeKalb, IL (United States). Dept. of Physics

    2016-03-27

    A novel approach for constructing fine-granularity scintillator calorimeters, based on the concept of an Integrated Readout Layer (IRL) was developed. The IRL consists of a printed circuit board inside the detector which supports the directly-coupled scintillator tiles, connects to the surface-mount SiPMs and carries the necessary front-end electronics and signal/bias traces. Prototype IRLs using this concept were designed, prototyped and successfully exposed to test beams. Concepts and implementations of an IRL carried out with funds associated with this contract promise to result in the next generation of scintillator calorimeters.

  14. The reduction of background signal in bismuth germanate scintillators

    International Nuclear Information System (INIS)

    Lewis, T.A.

    1986-07-01

    Bismuth germanate (BGO) is one of several new scintillator materials developed in recent years. It has similar energy resolution (6-8%) to sodium iodide (NaI) but it is non-hygroscopic, has a much better Peak-to-Compton ratio and a stopping power about 2.3 times greater than NaI. For counting activated foils it represents an improvement on NaI for high efficiency counting where the resolution of a germanium spectrometer is not required. Two scintillators bought for this purpose were found to have a higher than expected background signal between 500 keV and 2 MeV which was traced to Bi207, an active isotope of bismuth with a 38 year half-life and not listed as occurring naturally. Reference to the manufacturer showed all crystals to be similarly contaminated. It is speculated that this active isotope arises from cosmic proton activation of associated lead in the ore from which the bismuth is extracted. Although not confirmed rigorously it has been shown that bismuth extracted from ore with a low lead content does not contain Bi207. Scintillators have been manufactured from uncontaminated material and reductions in the background signal of more than an order of magnitude have been achieved. This reduction will be of immediate benefit for monitoring nickel foils (fast flux monitors) activated in zero-energy reactors and should also permit the exploitation of other low probability reactions previously not thought to be feasible. (author)

  15. Acquiring beam data for a flattening-filter free linear accelerator using organic scintillators

    DEFF Research Database (Denmark)

    Beierholm, Anders Ravnsborg; Behrens, C.F.; Hoffmann, L.

    2013-01-01

    Fibre-coupled organic scintillators have been proven a credible alternative to clinically implemented methods for radiotherapy dosimetry, primarily due to their water equivalence and good spatial resolution. Furthermore, the fast response of the scintillators can be exploited to perform time-reso...

  16. Fiber-optic multipoint radiation sensing system using waveguide scintillators

    International Nuclear Information System (INIS)

    Maekawa, Tatsuyuki; Yoda, Masaki; Tanaka, Koutarou; Masumaru, Tarou; Morimoto, Souichirou.

    1996-01-01

    Novel fiber-optic radiation sensors and a multipoint measurement method that takes advantage of them have been developed. The new sensor design, which we call a 'waveguide scintillator', consists of a scintillating material and a wavelength-shifting fiber (WLSF). The WLSF is embedded in the scintillating material, and each end is connected to a transparent optical fiber. These waveguide scintillators can be connected in series along an optical fiber loop to form a radiation monitoring system, and each end of the fiber loop is terminated with a photodetector. This new radiation monitoring arrangement dispenses with the need for electronic apparatus at each measuring point and consequently improves resistance to noise. Furthermore, it offers the advantages of multipoint monitoring - meaning that radiation intensity can be measured at multiple sensors - using only two photodetectors. We have examined the light output characteristics and time resolution of a prototype arrangement of these new waveguide scintillators, thus confirming the feasibility of multipoint measurements using a system of multiple waveguide scintillators connected in series in an optical fiber loop. (author)

  17. A scintillating bolometer array for double beta decay studies: The LUCIFER experiment

    Energy Technology Data Exchange (ETDEWEB)

    Gironi, L., E-mail: luca.gironi@mib.infn.it [Università degli Studi di Milano-Bicocca, Milano (Italy); INFN – Sezione di Milano-Bicocca, Milano (Italy)

    2016-07-11

    The main goal of the LUCIFER experiment is to study the neutrinoless double beta decay, a rare process allowed if neutrinos are Majorana particles. Although aiming at a discovery, in the case of insufficient sensitivity the LUCIFER technique will be the demonstrator for a higher mass experiment able to probe the entire inverted hierarchy region of the neutrino mass. In order to achieve this challenging result, high resolution detectors with active background discrimination capability are required. This very interesting possibility can be largely fulfilled by scintillating bolometers thanks to the simultaneous read-out of heat and light emitted by the interactions in the detector or by pulse shape analysis. - Highlights: • The LUCIFER technique will be the demonstrator for a higher mass experiment. • Scintillating bolometers allow high energy resolution and background discrimination. • The first choice for the LUCIFER tower are ZnSe crystals. • The LUCIFER setup will consist of an array of 30 individual single module detectors. • An array of ZnMoO4 crystals allowed the bolometric observation of the 2vDBD of {sup 100}Mo.

  18. Scintillating fiber tracking at high luminosities using Visible Light Photon counter readout

    International Nuclear Information System (INIS)

    Atac, M.

    1995-11-01

    This paper reviews the research work on the Visible Light Photon Counters (VLPC) that have been developed for the scintillating fiber tracking at high luminosity colliders and high rate fixed target experiments. The devices originated from the joint work between UCLA and Rockwell International Science Center. The VLPCs are capable of counting photons very efficiently down to a single photon level with high avalanche gain, producing pulses at very high rates with very short rise times. Due to small gain dispersions they can be used in counting photons with high quantum efficiencies, therefore they are excellent devices for charged particle tracking using small diameter scintillating plastic fibers. In this paper, fiber tracking for the CDF and D0 upgrades and a possible usage of the VLPC readout for the experiment E803 at Fermilab will be discussed

  19. Application of the Oslo method to high resolution gamma spectra

    Science.gov (United States)

    Simon, A.; Guttormsen, M.; Larsen, A. C.; Beausang, C. W.; Humby, P.

    2015-10-01

    Hauser-Feshbach statistical model is a widely used tool for calculation of the reaction cross section, in particular for astrophysical processes. The HF model requires as an input an optical potential, gamma-strength function (GSF) and level density (LD) to properly model the statistical properties of the nucleus. The Oslo method is a well established technique to extract GSFs and LDs from experimental data, typically used for gamma-spectra obtained with scintillation detectors. Here, the first application of the Oslo method to high-resolution data obtained using the Ge detectors of the STARLITER setup at TAMU is discussed. The GSFs and LDs extracted from (p,d) and (p,t) reactions on 152154 ,Sm targets will be presented.

  20. Climatology of GNPs ionospheric scintillation at high and mid latitudes under different solar activity conditions

    International Nuclear Information System (INIS)

    Spogli, L.; Alfonsi, L.; De Franceschi, G.; Romano, V.; Aquino, M.H.O.; Dodson, A.

    2010-01-01

    We analyze data of ionospheric scintillation over North European regions for the same period (October to November) of two different years (2003 and 2008), characterized by different geomagnetic conditions. The work aims to develop a scintillation climatology of the high- and mid-latitude ionosphere, analyzing the behaviour of the scintillation occurrence as a function of the magnetic local time (MLT) and of the altitude adjusted corrected magnetic latitude (M lat), to characterize scintillation scenarios under different solar activity conditions. The results shown herein are obtained merging observations from a network of GISTMs (GPS Ionospheric Scintillation and TEC Monitor) located over a wide range of latitudes in the northern hemisphere. Our findings confirm the associations of the occurrence of the ionospheric irregularities with the expected position of the auroral oval and of the ionospheric trough walls and show the contribution of the polar cap patches even under solar minimum conditions.

  1. Tl{sub 2}LaCl{sub 5} (Ce{sup 3+}): New fast and efficient scintillator for X- and γ-ray detection

    Energy Technology Data Exchange (ETDEWEB)

    Kim, H.J., E-mail: hongjoo@knu.ac.kr [Department of Physics, Kyungpook National University, Daegu 41566 (Korea, Republic of); Rooh, Gul [Department of Physics, Abdul Wali Khan University, Mardan 23200 (Pakistan); Kim, Sunghwan [Department of Radiological Science, Cheongju University, Cheongju 41566 (Korea, Republic of)

    2017-06-15

    Scintillation properties of the new Tl{sub 2}LaCl{sub 5}: xCe{sup 3+} where x=0, 0.5, 1 and 10 mol % (TLC: Ce{sup 3+}) single crystals are presented. Two zones vertical Bridgman technique is used for the growth of this scintillation material. High Z-number (79) of this material offer excellent detection efficiency for X- and γ-rays. Grown samples are characterized under X- and γ-rays excitation in order to find the emission wavelength, energy resolution, light yield, and decay time. Emission spectra exhibit Ce{sup 3+} emission bands between 350–550 nm and peaking at 389 nm. The obtained energy resolution and light yield increases with high Ce-concentration. Energy resolution and light yield of 10%Ce-doped sample are found to be 6.9% (FWHM) and 51,000±5000 ph/MeV, respectively at room temperature. For the grown samples, two exponential decay time constants are found. The measured decay time constants showed variation in their values with respect to Ce-concentrations in the host crystal. Fast decay time constant of 31 ns with 87% light emission is found for 10%Ce sample. Scintillation results suggested that TLC will be one of the promising next generation scintillator for the medical imaging techniques such as Positron Emission Tomography (PET).

  2. Geant4 simulation of a 3D high resolution gamma camera

    International Nuclear Information System (INIS)

    Akhdar, H.; Kezzar, K.; Aksouh, F.; Assemi, N.; AlGhamdi, S.; AlGarawi, M.; Gerl, J.

    2015-01-01

    The aim of this work is to develop a 3D gamma camera with high position resolution and sensitivity relying on both distance/absorption and Compton scattering techniques and without using any passive collimation. The proposed gamma camera is simulated in order to predict its performance using the full benefit of Geant4 features that allow the construction of the needed geometry of the detectors, have full control of the incident gamma particles and study the response of the detector in order to test the suggested geometries. Three different geometries are simulated and each configuration is tested with three different scintillation materials (LaBr3, LYSO and CeBr3)

  3. Liquid scintillation alpha particle spectrometry. Progress report

    International Nuclear Information System (INIS)

    Bell, L.L.; Hakooz, S.A.; Johnson, L.O.; Nieschmidt, E.B.; Meikrantz, D.H.

    1979-12-01

    Objective to develop a technique whereby Pu may be put into solution, extracted by solvent extraction into a suitable extractive scintillant and subsequently counted. Presented here are results of attempts to separate beta and alpha activities through pulse shape discrimination. A qualitative discussion is given which yields alpha particle peak widths, resolution and response. The detection efficiency for alpha particles in a liquid scintillant is 100%. Present detection sensitivities of the equipment being used are: 4.5 x 10 -6 μCi (100 s), 1.2 x 10 -6 μCi (1000 s), and 4.0 x 10 -7 μCi (10,000 s) at the 3 sigma level. The detectability of a particular alpha-emitting species is strongly dependent upon the population of other species. The ability to discriminate depends upon the system resolution. 14 figures, 2 tables

  4. Ultrafast readout of scintillating fibres using upgraded position-sensitive photomultipliers

    CERN Document Server

    Agoritsas, V; Ditta, J; Dufournaud, J; Giacomich, R; Gorin, A M; Kuroda, K; Meshchanin, A P; Newsom, C R; Nurushev, S B; Önel, Y M; Okada, K; Oshima, N; Pauletta, G; Penzo, Aldo L; Rakhmatov, V E; Rykalin, V I; Salvato, G; Schiavon, R P; Sillou, D; Solovyanov, V L; Takeutchi, F; Vasilev, V; Vasilchenko, V G; Villari, A C C; Yamada, R; Yoshida, T; CERN. Geneva. Detector Research and Development Committee

    1991-01-01

    In view of the new possibilities for event detection and tracking in future multi-TeV collider experiments, we propose to improve the performance of position-sensitive photomultipliers and, with it, to realize an ultrafast readout device of scintillating fibres; this should play a unique role in the complex of a future vertex detector, owing to its inherent subnanosecond resolving time as well as its capability of an extremely high counting rate. Our proposal is first aimed at upgrading the position-sensitive PM, in particular its space and time resolutions. Full advantage of the new phototube will be demonstrated in its immediate application to a generic prototype of a scintillating-fibre detector. Our programme also includes intensive R&D on a real-time digitization of the multihit topology, which should provide an essential back-up to the vertex tracking at extremely high rates, one of the most difficult problems relevant to the expected high performance of the LHC.

  5. Evaluation of New Inorganic Scintillators for Application in a Prototype Small Animal PET Scanner

    CERN Document Server

    Kuntner, C

    2003-01-01

    In the study of new pharmaceuticals as well as brain and genetic research, Positron Emission Tomography (PET) is a useful method. It has also recently entered the clinical domain in cardiology and particularly in oncology. Small animals such as mice, are often used to validate sophisticated models of human disease. High spatial resolution PET instrumentation is therefore necessary due to the reduced dimensions of the organs. Inorganic scintillators are employed in most of the diagnostic imaging devices. The ultimate performance of the PET scanner is tightly bound to the scintillation properties of the crystals. In the last years there has been an effort to develop new scintillating materials characterized by high light output, high detection efficiency and fast decay time. The most studied systems are mainly Ce3+-doped crystals such as LSO:Ce, YAP:Ce, LuAP:Ce, and recently also mixed Lux(RE3+)1-xAlO3:Ce crystals. These crystals are very attractive for medical application because of their high density (with th...

  6. Characterization of some modern scintillators recommended for use on large fusion facilities in γ-ray spectroscopy and tomographic measurements of γ-emission profiles

    Directory of Open Access Journals (Sweden)

    Sibczynski Pawel

    2017-09-01

    Full Text Available LaBr3:Ce,CeBr3 and GAGG:Ce scintillators were investigated and the determined characteristics were compared with those obtained for the well-known and widely used CsI:Tl and NaI:Tl crystals. All the detectors were of the same size of 10 × 10 × 5 mm3. The aim of this test study was to single out scintillation detectors most suitable for γ-ray spectrometry and γ-ray emission radial profile measurements in high-temperature plasma experiments. Decay time, energy resolution, non-proportionality and full energy peak detection efficiency ere measured for γ-ray energies up to 1770 keV. Due to their good energy resolution, short decay time and high detection efficiency for MeV gamma rays, LaBr3:Ce and CeBr3 scintillators are proposed as the best candidates for use especially under conditions of high count rates, which are expected in the forthcoming DT experiments.

  7. A new spectroscopic imager for X-rays from 0.5 keV to 150 keV combining a pnCCD and a columnar CsI(Tl) scintillator

    Science.gov (United States)

    Schlosser, D. M.; Hartmann, R.; Kalok, D.; Bechteler, A.; Abboud, A.; Shokr, M.; Çonka, T.; Pietsch, U.; Strüder, L.

    2017-04-01

    By combining a low noise fully depleted pnCCD detector with a columnar CsI(Tl) scintillator an energy dispersive spatial resolving detector can be realized with a high quantum efficiency in the range from below 0.5 keV to above 150 keV. The used scintillator system increases the pulse height of gamma-rays converted in the CsI(Tl), due to focusing properties of the columnar scintillator structure by reducing the event size in indirect detection mode (conversion in the scintillator). In case of direct detection (conversion in the silicon of the pnCCD) the relative energy resolution is 0.7% at 122 keV (FWHM = 850 eV) and the spatial resolution is less than 75 μm. In case of indirect detection the relative energy resolution, integrated over all event sizes is about 9% at 122 keV with an expected spatial precision of below 75 μm.

  8. Highly efficient solid-state neutron scintillators based on hybrid sol-gel nanocomposite materials

    International Nuclear Information System (INIS)

    Kesanli, Banu; Hong, Kunlun; Meyer, Kent; Im, Hee-Jung; Dai, Sheng

    2006-01-01

    This research highlights opportunities in the formulation of neutron scintillators that not only have high scintillation efficiencies but also can be readily cast into two-dimensional detectors. Series of transparent, crack-free monoliths were prepared from hybrid polystyrene-silica nanocomposites in the presence of arene-containing alkoxide precursor through room temperature sol-gel processing. The monoliths also contain lithium-6 salicylate as a target material for neutron-capture reactions and amphiphilic scintillator solution as a fluorescent sensitizer. Polystyrene was functionalized by trimethoxysilyl group in order to enable the covalent incorporation of aromatic functional groups into the inorganic sol-gel matrices for minimizing macroscopic phase segregation and facilitating lithium-6 doping in the sol-gel samples. Neutron and alpha responses of these hybrid polystyrene-silica monoliths were explored

  9. A pill-box design, flow type, gas scintillation proportional counter

    International Nuclear Information System (INIS)

    Garg, S.P.; Sharma, R.C.; Bhati, S.; Somasundaram, S.

    1982-01-01

    A gas scintillation proportional counter of 'pill-box' design operated with argon + 2.5% nitrogen gas in continuous flow, has been developed. An energy resolution of 1.6% is obtained for 239 Pu α-particles emitted from a mixed nuclide source of 239 Pu- 241 Am- 244 Cm and injected into the counter parallel to the anode. The risetime of the scintillation pulse is found to be less than 0.5 μs. Measurements have been made of charge and light gain factors as a function of anode voltage. It is found that for a given anode voltage, the scintillation pulse amplitude increases sharply with the addition of nitrogen to argon and reaches a maximum at about 2.5% and then decreases slowly, whereas the charge pulse amplitude reduces monotonically. Nitrogen improvement factors with the addition of 2.5% nitrogen to argon are found to be different for two photomultipliers with different photocathode responses. The improvement in energy resolution as a result of addition of nitrogen to argon is discussed. Comments are made on the intrinsic energy resolution capabilities of such a counter. (orig.)

  10. A high resolution TOF-PET concept with axial geometry and digital SiPM readout

    CERN Document Server

    Casella, C; Joram, C; Schneider, T

    2014-01-01

    The axial arrangement of long scintillation crystals is a promising concept in PET instrumentation to address the need for optimized resolution and sensitivity. Individual crystal readout and arrays of wavelength shifter strips placed orthogonally to the crystals lead to a 3D-detection of the annihilations photons. A fully operational demonstrator scanner, developed by the AX-PET collaboration, proved the potential of this concept in terms of energy and spatial resolution as well as sensitivity. This paper describes a feasibility study, performed on axial prototype detector modules with 100 mm long LYSO crystals, read out by the novel digital Silicon Photomultipliers (dSiPM) from Philips. With their highly integrated readout electronics and excellent intrinsic time resolution, dSiPMs allow for compact, axial detector modules which may extend the potential of the axial PET concept by time of fl ight capabilities (TOF-PET). A coincidence time resolution of 211 ps (FWHM) was achieved in the coincidence of two ax...

  11. High energy gamma ray response of liquid scintillator

    International Nuclear Information System (INIS)

    Shigyo, N.; Ishibashi, K.; Matsufuji, N.; Nakamoto, T.; Numajiri, M.

    1994-01-01

    We made the experiment on the spallation reaction. NE213 organic liquid scintillators were used for measuring neutrons and γ rays. To produce the γ ray emission cross section, we used the response functions by EGS4 code. The response functions look like uniform above γ ray energies of 60 MeV. The experimental data of the γ ray emission cross section are different from the data of High Energy Transport Code. (author)

  12. Linear position sensitive neutron detector using fiber optic encoded scintillators

    International Nuclear Information System (INIS)

    Davidson, P.L.; Wroe, H.

    1983-01-01

    A linear position sensitive slow neutron detector with 3 mm resolution is described. It uses the fiber optic coding principle in which the resolution elements are separate pieces of lithium loaded glass scintillator each coupled by means of flexible polymer optical fibers to a unique combination of 3 photo multipliers (PM's) out of a bank of 12. A decoder circuit repsponds to a triple coincidence between PM outputs and generates a 12 bit work which identifies the scintillator element which stopped the incident neutron. Some details of the construction and decoding electronics are given together with test results obtained using a laboratory isotope neutron source and a monochomated, collimated neutron beam from a reactor. The count rate in the absence of neutron sources is 2 to 3 c min - 1 per element; the element to element variation in response to a uniform flux is a few percent for 95% of the elements; the resolution as measured by a 1 mm wide prode neutron beam is 3 mm; the relative long term stability is about 0.1% over 3 days and the detection efficiency measured by comparison with an end windowed, high pressure gas counter is about 65% at a neutron wavelength of 0.9A 0

  13. A Review of Ionospheric Scintillation Models.

    Science.gov (United States)

    Priyadarshi, S

    This is a general review of the existing climatological models of ionospheric radio scintillation for high and equatorial latitudes. Trans-ionospheric communication of radio waves from transmitter to user is affected by the ionosphere which is highly variable and dynamic in both time and space. Scintillation is the term given to irregular amplitude and phase fluctuations of the received signals and related to the electron density irregularities in the ionosphere. Key sources of ionospheric irregularities are plasma instabilities; every irregularities model is based on the theory of radio wave propagation in random media. It is important to understand scintillation phenomena and the approach of different theories. Therefore, we have briefly discussed the theories that are used to interpret ionospheric scintillation data. The global morphology of ionospheric scintillation is also discussed briefly. The most important (in our opinion) analytical and physical models of scintillation are reviewed here.

  14. Tests of Scintillator+WLS Strips for Muon System at Future Colliders

    Energy Technology Data Exchange (ETDEWEB)

    Denisov, Dmitri [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Evdokimov, Valery [Inst. for High Energy Physics (IHEP), Protvino (Russian Federation); Lukić, Strahinja [Univ. of Belgrade (Serbia)

    2015-10-11

    Prototype scintilator+WLS strips with SiPM readout for muon system at future colliders were tested for light yield, time resolution and position resolution. Depending on the configuration, light yield of up to 36 photoelectrons per muon per SiPM has been achieved, as well as time resolution of 0.5 ns and position resolution of ~ 7 cm.

  15. Fine-grained hodoscopes based on scintillating optical fibers

    International Nuclear Information System (INIS)

    Borenstein, S.R.; Strand, R.C.

    1981-01-01

    In order to exploit the high event rates at ISABELLE, it will be necessary to have fast detection with fine spatial resolution. The authors are currently constructing a prototype fine-grained hodoscope, the elements of which are scintillating optical fibers. The fibers have been drawn from commercially available plastic scintillator which has been clad with a thin layer of silicone. So far it has been demonstrated with one mm diameter fibers, that with a photodetector at each end, the fibers are more than 99% efficient for lengths of about 60 cm. The readout will be accomplished either with small diameter photomultiplier tubes or avalanche photodiodes used either in the linear or Geiger mode. The program of fiber development and evaluation is described. The status of the APD as a readout element is discussed, and an optical encoding readout scheme is described for events of low multiplicity

  16. Mechanical design of a high-resolution x-ray powder diffractometer at the Advanced Photon Source.

    Energy Technology Data Exchange (ETDEWEB)

    Shu, D.; Lee, P.; Preissner, C.; Ramanathan, M.; Beno, M.; VonDreele, R.; Ranay, R.; Ribaud, L.; Kurtz, C.; Jiao, X.; Kline, D.; Jemian, P.; Toby, B.

    2007-01-01

    A novel high-resolution x-ray powder diffractometer has been designed and commissioned at the bending magnet beamline 11-BM at the Advanced Photon Source (APS), Argonne National Laboratory (ANL). This state-of-the-art instrument is designed to meet challenging mechanical and optical specifications for producing high-quality powder diffraction data with high throughput. The 2600 mm (H) X 2100 mm (L) X 1700 mm (W) diffractometer consists of five subassemblies: a customized two-circle goniometer with a 3-D adjustable supporting base; a twelve-channel high-resolution crystal analyzer system with an array of precision x-ray slits; a manipulator system for a twelve scintillator x-ray detectors; a 4-D sample manipulator with cryo-cooling capability; and a robot-based sample exchange automation system. The mechanical design of the diffractometer as well as the test results of its positioning performance are presented in this paper.

  17. Mechanical design of a high-resolution x-ray powder diffractometer at the Advanced Photon Source

    International Nuclear Information System (INIS)

    Shu, D.; Lee, P.; Preissner, C.; Ramanathan, M.; Beno, M.; VonDreele, R.; Ranay, R.; Ribaud, L.; Kurtz, C.; Jiao, X.; Kline, D.; Jemian, P.; Toby, B.

    2007-01-01

    A novel high-resolution x-ray powder diffractometer has been designed and commissioned at the bending magnet beamline 11-BM at the Advanced Photon Source (APS), Argonne National Laboratory (ANL). This state-of-the-art instrument is designed to meet challenging mechanical and optical specifications for producing high-quality powder diffraction data with high throughput. The 2600 mm (H) X 2100 mm (L) X 1700 mm (W) diffractometer consists of five subassemblies: a customized two-circle goniometer with a 3-D adjustable supporting base; a twelve-channel high-resolution crystal analyzer system with an array of precision x-ray slits; a manipulator system for a twelve scintillator x-ray detectors; a 4-D sample manipulator with cryo-cooling capability; and a robot-based sample exchange automation system. The mechanical design of the diffractometer as well as the test results of its positioning performance are presented in this paper.

  18. Shock-resistant scintillation detector

    International Nuclear Information System (INIS)

    Novak, W.P.

    1979-01-01

    A unique scintillation detector unit is disclosed which employs a special light transfer and reflector means that encases and protects the scintillator crystal against high g forces. The light transfer means comprises a flexible silicon rubber optical material bonded between the crystal and the optical window and having an axial thickness sufficient to allow the scintillator to move axially inside the container under high g forces without destroying the bonds. The reflector means comprises a soft elastic silicone rubber sleeve having a multiplicity of closely arranged tapered protrusions radiating toward and engaging the periphery of the scintillator crystal to cushion shocks effectively and having a reflective material, such as aluminum oxide powder, in the spaces between the protrusions. The reflector means provides improved shock absorption because of the uniform support and cushioning action of the protrusions and also provides the detector with high efficiency. The silicon rubber composition is specially compounded to include a large amount of aluminum oxide which enables the rubber to function effectively as a light reflector

  19. Luminescent properties of composite scintillators based on PPO and o-POPOP doped SiO{sub 2} xerogel matrices

    Energy Technology Data Exchange (ETDEWEB)

    Viagin, O., E-mail: viagin@isma.kharkov.ua [Institute for Scintillation Materials of NAS of Ukraine, 60 Science Ave., 61001 Kharkiv (Ukraine); Masalov, A.; Bespalova, I.; Zelenskaya, O.; Tarasov, V.; Seminko, V.; Voloshina, L. [Institute for Scintillation Materials of NAS of Ukraine, 60 Science Ave., 61001 Kharkiv (Ukraine); Zorenko, Yu. [Institute of Physics of Kazimierz Wielki University of Bydgoszcz, 2 Powstańców Wielkopolskich str., 85-090 Bydgoszcz (Poland); Malyukin, Yu. [Institute for Scintillation Materials of NAS of Ukraine, 60 Science Ave., 61001 Kharkiv (Ukraine)

    2016-11-15

    New composite scintillation detectors were obtained by incorporation of PPO and o-POPOP organic scintillators into porous sol–gel silica matrices. Composites possess high photoluminescence intensity and decay time in nanosecond range. The absolute light yield of composite scintillators at excitation by alpha-radiation is about 4000–5000 photons/MeV and the pulse–height resolution is about 30%. The investigations of time-resolved luminescence of composites performed under excitation by synchrotron radiation in the 3.7–25 eV range have shown that the non-radiative energy transfer between host matrix and dopant molecules occurs via singlet states of SiO{sub 2} oxygen-deficient centers.

  20. Construction and performance of a cylindrical scintillating fiber detector for experiment 835 at FNAL

    International Nuclear Information System (INIS)

    Ambrogiani, M.; Baldini, W.; Bettoni, D.

    1996-01-01

    A tracking detector made of scintillating fibers has been built for the Fermilab experiment E835. The tracker is being used for a high resolution measurement of the polar angle θ and to provide a first level trigger, exploiting the fast response and very good time resolution of the signal from the fibers. The small amount of light from the fibers is detected by solid state devices (VLPC: Visible Light Photon Counters), with very high quantum efficiency. This paper reports about the construction of the tracker and gives the first results on the detector performance: light yield/mip, efficiency, signal homogeneity and time resolution

  1. Scintillation quenching in BGO crystal of the Solar Orbiter HET

    Energy Technology Data Exchange (ETDEWEB)

    Grunau, J.; Kulkarni, Shrinivasrao; Martin, C.; Boettcher, Stephan; Seimetz, L.; Schuster, B.; Kulemzin, A.; Wimmer-Schweingruber, Robert F. [IEAP, Christian-Albrechts-Universitaet zu Kiel (Germany)

    2013-07-01

    The High-Energy Telescope (HET) on ESA's Solar Orbiter mission will measure electrons from 300 keV up to about 30 MeV, protons from 10 to 100 MeV and heavy ions from approximately 20 to 200 MeV/nuc. These measurement capabilities are reached by a combination of solid-state tracking detectors and a scintillator calorimeter. This setup can perform particle identification via the dE/dx vs total E technique. The scintillator approach provides a good resolution over the complete energy range but the total energy deposition has to be corrected for the scintillation quenching. The quenching lowers light output depending on the type and energy of the incident particle. We measured the crystal response for different heavy ions and energies and compared them to simulated values. Simulations were carried out using the GEANT4 toolkit provided by CERN. From comparison of simulated and measured data we were able to calculate quenching factors for the BGO crystals for ions up to iron. The results are of great interest for later data analysis with the HET telescope.

  2. Performance evaluation of LaBr3: Ce scintillator

    International Nuclear Information System (INIS)

    Xie Ming; Lin Li; Liu Shihao; Xiao Peng; Xie Qingguo

    2012-01-01

    The cerium doped lanthanum bromide crystal (LaBr 3 : Ce) is a new kind of scintillator with many advantages such as good energy resolution, high light output, short decay time, good proportionality response. These properties make the LaBr 3 : Ce attractive substantial interest to use in the radiation detection. The energy resolution were investigated with Φ25 × 25 mm LaBr 3 : Ce coupled to a Hamamatsu R8900 photomultiplier tube. Energy resolution of 3.6% (FWHM) have been achieved for 511 keV photons ( 18 F source) at room temperature. Decay time constant of 20 ns have been acquired with a Hamamatsu fast-time-response R9800 photomultiplier tube. The results approve the excellent characterizations of LaBr 3 : Ce and imply its enormous potentiality in the radiation detectors of gamma-ray spectroscopy and PET. (authors)

  3. Synthesis of plastic scintillation microspheres: Evaluation of scintillators

    International Nuclear Information System (INIS)

    Santiago, L.M.; Bagán, H.; Tarancón, A.; Garcia, J.F.

    2013-01-01

    The use of plastic scintillation microspheres (PSm) appear to be an alternative to liquid scintillation for the quantification of alpha and beta emitters because it does not generate mixed wastes after the measurement (organic and radioactive). In addition to routine radionuclide determinations, PSm can be used for further applications, e.g. for usage in a continuous monitoring equipment, for measurements of samples with a high salt concentration and for an extractive scintillation support which permits the separation, pre-concentration and measurement of the radionuclides without additional steps of elution and sample preparation. However, only a few manufacturers provide PSm, and the low number of regular suppliers reduces its availability and restricts the compositions and sizes available. In this article, a synthesis method based on the extraction/evaporation methodology has been developed and successfully used for the synthesis of plastic scintillation microspheres. Seven different compositions of plastic scintillation microspheres have been synthesised; PSm1 with polystyrene, PSm2 with 2,5-Diphenyloxazol(PPO), PSm3 with p-terphenyl (pT), PSm4 with PPO and 1,4-bis(5-phenyloxazol-2-yl) (POPOP), PSm5 pT and (1,4-bis [2-methylstyryl] benzene) (Bis-MSB), PSm6 with PPO, POPOP and naphthalene and PSm7 with pT, Bis-MSB and naphthalene. The synthesised plastic scintillation microspheres have been characterised in terms of their morphology, detection capabilities and alpha/beta separation capacity. The microspheres had a median diameter of approximately 130 μm. Maximum detection efficiency values were obtained for the PSm4 composition as follows 1.18% for 3 H, 51.2% for 14 C, 180.6% for 90 Sr/ 90 Y and 76.7% for 241 Am. Values of the SQP(E) parameter were approximately 790 for PSm4 and PSm5. These values show that the synthesised PSm exhibit good scintillation properties and that the spectra are at channel numbers higher than in commercial PSm. Finally, the addition

  4. The development of a single-crystal fiber-array scintillator area detector

    International Nuclear Information System (INIS)

    Loong, Chun; Vitt, Richard; Sayir, Ali; Sayir, Haluk

    2001-01-01

    The scientific output of a neutron instrument is directly proportional to the effectiveness of its detector system-coverage of scattering area, pixel resolution, counting efficiency, signal-to-noise ratio, life time and cost. The current neutron scintillator detectors employ mainly 6 Li-doped glass and ZnS, both of which present well-know limitations such as low light output, high gamma sensitivity in the case of 6 Li-glass and optical opacity in the case of ZnS. We aim to develop a position-sensitive, flight-time differentiable, efficient and cost-effective neutron detector system based on single-crystal scintillator fiber-arrays. The laser-heated melt modulation fiber growth technology developed at NASA provides the means to grow high-purity single-crystal fibers or rods of variable diameters (200 μm to 5 mm) and essentially unlimited length. Arrays of such fibers can be tailored to meet the requirements of pixel size, geometric configuration, and coverage area for a detector system. We report a plan in the growth and characterization of scintillators based on lithium silicates and boron aluminates using Ce as activator. (author)

  5. Tests of crossed-wire position sensitive photomultipliers for scintillating fiber particle tracking

    International Nuclear Information System (INIS)

    Perdrisat, C.F.; Koechner, D.; Majewski, S.; Pourang, R.; Wilson, C.D.; Zorn, C.

    1995-01-01

    Several applications of two Hamamatsu position sensitive photomultiplier tubes to the detection of high energy particles with scintillating fibers are discussed. The PMTs are of the multiwire anode grid design, type R2486 and R4135. These tubes were tested with both single samples and arrays of 2 and 3 mm diameter scintillating fibers. Measurements of position resolution of the PMTs using either the charge digitization or the delay line readout techniques were made. The results indicate an intrinsic inability of the technique to reconstruct the actual position of a fiber on the photocathode when its location falls halfway between two grid wires. A way to overcome this limit is suggested. (orig.)

  6. High-resolution gamma spectroscopy with whole-body and partial-body counters. Experience, recommendations. Report

    International Nuclear Information System (INIS)

    Sahre, P.

    1997-12-01

    The application of high-resolution gamma spectroscopy with whole-body and partial-body counters shows a steadily rising upward trend over the last few years. This induced the ''Arbeitskreis Inkorporationsueberwachung'' of the association ''Fachverband fuer Strahlenschutz e.V.'' to organise a meeting for joint elaboration of a guide on recommended applications of this measuring technique, based on a review of existing experience and results. A key item on the agenda of the meeting was the comparative evaluation of the Ge semiconductor detector and the NaI solid scintillation detector. (orig./CB) [de

  7. High resolution measurements and study of the neutron inelastic scattering reaction on 56Fe

    International Nuclear Information System (INIS)

    Dupont, E.

    1998-01-01

    High resolution measures of neutrons inelastic scattering cross section, have been performed on 56 Fe from 862 KeV to 3 MeV. The time of flight method has been used on the GELINA source of the IRMM in Geel (Belgium). Four barium fluoride scintillators, placed around the samples, recorded the gamma rays emissions coming from the iron and the boron. A study of the correlations between the partial elastic and inelastic lengths has been performed taking into account first transmission measures realized at Geel. (A.L.B.)

  8. Gamma-ray detection with an UV-enhanced photodiode and scintillation crystals emitting at short wavelengths

    International Nuclear Information System (INIS)

    Johansen, G.A.

    1997-01-01

    A low-noise ion implanted photodiode with high spectral response in the deep blue/UV region has been tested as read-out device for scintillation crystals with matching emission spectra (YAP(Ce), GSO(Ce), BGO and CsI(Tl)). This gamma-ray detector concept is attractive in many industrial applications where compactness, reliability and ambient temperature operation are important. The results show that the amount of detected scintillation light energy falls rapidly off as the wavelength of the scintillation light decreases. It is concluded that the dynamic spectral response of the photodiode, due to increasing carrier collection times, is considerably less than the DC response at short wavelengths. The diode is not useful in pulse mode operation with scintillation crystals emitting at wavelengths below about 400 nm. For read-out of CsI(Tl) with 661.6 keV gamma-radiation, however, the photodiode concept shows better energy resolution (7.1%) than other detectors. (orig.)

  9. Timing performance of ZnO:Ga nanopowder composite scintillators

    Energy Technology Data Exchange (ETDEWEB)

    Turtos, Rosana M. [Universita degli Studi di Milano-Bicocca, Milano (Italy); Gundacker, Stefan; Lucchini, Marco T.; Lecoq, Paul; Auffray, Etiennette [CERN, Geneva (Switzerland); Prochazkova, Lenka; Cuba, Vaclav [Czech Technical University, Faculty of Nuclear Sciences and Physical Engineering, Prague (Czech Republic); Buresova, Hana [Nuvia a.s, Kralupy nad Vltavou (Czech Republic); Mrazek, Jan [Institute of Photonics and Electronics AS CR, Prague (Czech Republic); Nikl, Martin [Institute of Physics of the AS CR, Prague (Czech Republic)

    2016-11-15

    The implementation of nanocrystal-based composite scintillators as a new generation of ultrafast particle detectors is explored using ZnO:Ga nanopowder. Samples are characterized with a spectral-time resolved photon counting system and pulsed X-rays, followed by coincidence time resolution (CTR) measurements under 511 keV gamma excitation. Results are comparable to CTR values obtained using bulk inorganic scintillators. Bringing the ZnO:Ga nanocrystal's timing performance to radiation detectors could pave the research path towards sub-20 ps time resolution as shown in this contribution. However, an efficiency boost when placing nanopowders in a transparent host constitutes the main challenge in order to benefit from sub-nanosecond recombination times. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  10. Development of NaI(Tl) scintillating films for imaging soft x-rays

    International Nuclear Information System (INIS)

    Shepherd, J.A.

    1993-01-01

    Thin film NaI(Tl) scintillators, of areas of up to 130 cm 2 , have been fabricated and characterized for use on soft x-ray imaging photomultiplier tubes. Relevant parameters of photon-counting imaging detectors are defined and used to predict the performance of several materials, including CsI(Na), CsI(Tl), CaF 2 (Eu), Lu 2 (SiO 4 )O:Ce, and NaI(Tl), as thin film scintillators on fiber optic substrates. Also, x-ray imaging methodologies are compared. The NaI(Tl) films were vapor-deposited onto quartz and fiber optic substrates using a powder flash deposition technique. When compared to single crystal NaI(Tl), the films were found to have equally high light yield but lower energy resolution. Light yield optimization was studied in detail including the effects of substrate temperature, activator concentration in the evaporant, and boat temperature. Spatial resolution as well as parallax errors are discussed and measured for film thicknesses up to 61 μm. A technique is described that can substantially increase the light collection of high index films on fiber optic disks. The light collection was improved by 20% by coating the disk with potassium silicate before the NaI(Tl) deposition. Large area films, up to 130 cm 2 , had a spatial uniformity of response within ±1.5% for count rate and ±3.5% for light yield, and their spatial resolution exceeded 16.6 lp mm -1 when deposited onto fiber optic substrates. The 8-keV x-ray detection efficiency of the microchannel plate imaging photomultiplier tube coupled to a NaI(Tl) film scintillator is predicted to be 88%. Other uses for the films are also described

  11. Scintillation response of organic and inorganic scintillators

    CERN Document Server

    Papadopoulos, L M

    1999-01-01

    A method to evaluate the scintillation response of organic and inorganic scintillators to different heavy ionizing particles is suggested. A function describing the rate of the energy consumed as fluorescence emission is derived, i.e., the differential response with respect to time. This function is then integrated for each ion and scintillator (anthracene, stilbene and CsI(Tl)) to determine scintillation response. The resulting scintillation responses are compared to the previously reported measured responses. Agreement to within 2.5% is observed when these data are normalized to each other. In addition, conclusions regarding the quenching parameter kB dependence on the type of the particle and the computed values of kB for certain ions are included. (author)

  12. Neutron spectrometer using NE218 liquid scintillator

    International Nuclear Information System (INIS)

    Dance, J.B.; Francois, P.E.

    1976-01-01

    A neutron spectrometer has been constructed using NE218 liquid scintillator. Discrimination against electron-gamma events was obtained usng a charge-comparison pulse shape discrimination system. The resolution obtained was about 0.25 MeV F.W.H.M. at 2.0 MeV

  13. Efficient methodologies for system matrix modelling in iterative image reconstruction for rotating high-resolution PET

    Energy Technology Data Exchange (ETDEWEB)

    Ortuno, J E; Kontaxakis, G; Rubio, J L; Santos, A [Departamento de Ingenieria Electronica (DIE), Universidad Politecnica de Madrid, Ciudad Universitaria s/n, 28040 Madrid (Spain); Guerra, P [Networking Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Madrid (Spain)], E-mail: juanen@die.upm.es

    2010-04-07

    A fully 3D iterative image reconstruction algorithm has been developed for high-resolution PET cameras composed of pixelated scintillator crystal arrays and rotating planar detectors, based on the ordered subsets approach. The associated system matrix is precalculated with Monte Carlo methods that incorporate physical effects not included in analytical models, such as positron range effects and interaction of the incident gammas with the scintillator material. Custom Monte Carlo methodologies have been developed and optimized for modelling of system matrices for fast iterative image reconstruction adapted to specific scanner geometries, without redundant calculations. According to the methodology proposed here, only one-eighth of the voxels within two central transaxial slices need to be modelled in detail. The rest of the system matrix elements can be obtained with the aid of axial symmetries and redundancies, as well as in-plane symmetries within transaxial slices. Sparse matrix techniques for the non-zero system matrix elements are employed, allowing for fast execution of the image reconstruction process. This 3D image reconstruction scheme has been compared in terms of image quality to a 2D fast implementation of the OSEM algorithm combined with Fourier rebinning approaches. This work confirms the superiority of fully 3D OSEM in terms of spatial resolution, contrast recovery and noise reduction as compared to conventional 2D approaches based on rebinning schemes. At the same time it demonstrates that fully 3D methodologies can be efficiently applied to the image reconstruction problem for high-resolution rotational PET cameras by applying accurate pre-calculated system models and taking advantage of the system's symmetries.

  14. Molecular imaging: High-resolution detectors for early diagnosis and therapy monitoring of breast cancer

    Energy Technology Data Exchange (ETDEWEB)

    Garibaldi, F. [Istituto Superiore di Sanita and INFN-gr. Sanita-Rome (Italy)]. E-mail: Franco.garibaldi@iss.infn.it; Cisbani, E. [Istituto Superiore di Sanita and INFN-gr. Sanita-Rome (Italy); Colilli, S. [Istituto Superiore di Sanita and INFN-gr. Sanita-Rome (Italy); Cusanno, F. [Istituto Superiore di Sanita and INFN-gr. Sanita-Rome (Italy); Fratoni, R. [Istituto Superiore di Sanita and INFN-gr. Sanita-Rome (Italy); Giuliani, F. [Istituto Superiore di Sanita and INFN-gr. Sanita-Rome (Italy); Gricia, M. [Istituto Superiore di Sanita and INFN-gr. Sanita-Rome (Italy); Lucentini, M. [Istituto Superiore di Sanita and INFN-gr. Sanita-Rome (Italy); Fratoni, R. [Istituto Superiore di Sanita and INFN-gr. Sanita-Rome (Italy); Lo Meo, S. [Istituto Superiore di Sanita and INFN-gr. Sanita-Rome (Italy); Magliozzi, M.L. [Istituto Superiore di Sanita and INFN-gr. Sanita-Rome (Italy); Santanvenere, F. [Istituto Superiore di Sanita and INFN-gr. Sanita-Rome (Italy); Cinti, M.N. [University La Sapienza, Rome (Italy); Pani, R. [University La Sapienza, Rome (Italy); Pellegrini, R. [University La Sapienza, Rome (Italy); Simonetti, G. [University Tor Vergata, Rome (Italy); Schillaci, O. [University Tor Vergata, Rome (Italy); Del Vecchio, S. [CNR Napoli, Naples (Italy); Salvatore, M. [CNR Napoli, Naples (Italy); Majewski, S. [Jefferson Lab, Newport News, VA (United States); Lanza, R.C. [Massachusetts Institute of Technology, Cambridge, MA (United States); De Vincentis, G. [University La Sapienza, Rome (Italy); Scopinaro, F. [University La Sapienza, Rome (Italy)

    2006-12-20

    Dedicated high-resolution detectors are required for detection of small cancerous breast tumours by molecular imaging with radionuclides. Absorptive collimation is normally applied in imaging single photon emitters, but it results in a strong reduction in detection efficiency. Systems based on electronic collimation are complex and expensive. For these reasons simulations and measurements have been performed to design optimised dedicated high-resolution mini gamma camera. Critical parameters are contrast and signal-to-noise ratio (SNR). Intrinsic performance (spatial resolution, pixel identification, and response linearity and uniformity) were first optimised. Pixellated scintillator arrays (NaI(Tl)) of different pixel size were coupled to arrays of PSPMTs with different anode pad dimensions (6x6 mm{sup 2} and 3x3 mm{sup 2}). Detectors having a field of view (FOV) of 100x100 mm{sup 2} and 150x200 mm{sup 2} were designed and built. The electronic system allows read out of all the anode pad signals. The collimation technique was then considered and limits of coded aperture option were studied. Preliminary results are presented.

  15. Scintillator calorimeters for a future linear collider experiment

    Energy Technology Data Exchange (ETDEWEB)

    Hartbrich, Oskar

    2016-07-15

    shower start shows considerable differences between physics lists, especially for the higher end of beam energies available in this analysis. Two separate energy reconstruction algorithms are presented in this thesis. The standard reconstruction uses constant weights per sub-detector to reconstruct the primary pion energy. The implementation of a software compensation reconstruction developed for this analysis aims to distinguish electromagnetic sub-shower depositions in hadronic showers by the deposited energy in each hit. The implementation differs from a previous software compensation scheme used within CALICE by forcing less dependencies on the shapes of the optimised weights, increasing the number of free parameters but ultimately resulting in a more stable parameter optimisation. The software compensation reconstruction improves the energy resolution of data events by 10% to 20%. Applying the software compensation weights obtained from simulations to data events yields a similar performance compared to the native data weights, slightly degrading the response linearity while even slightly improving the energy resolution. The calorimeter prototypes used in the testbeam analysis presented in this thesis were built to prove the general feasibility of high granularity scintillator-SiPM calorimeters, which they fully accomplished. To demonstrate the scalability of such calorimeters to the size and requirements of a full-scale particle physics experiment as ILD, second generation prototypes with fully integrated readout electronics are developed within the CALICE collaboration. A toy simulation study performed for this thesis shows that the development of scintillator-SiPM tile systems should target a lightyield of 15 (px)/(MIP) in order to maintain a 95% MIP efficiency even for 2σ outliers, when assuming a hit energy threshold of 0.5 MIP. An efficient method to extract and validate trigger thresholds positions for all cells of the detector system is presented, requiring

  16. Scintillator calorimeters for a future linear collider experiment

    International Nuclear Information System (INIS)

    Hartbrich, Oskar

    2016-07-01

    shower start shows considerable differences between physics lists, especially for the higher end of beam energies available in this analysis. Two separate energy reconstruction algorithms are presented in this thesis. The standard reconstruction uses constant weights per sub-detector to reconstruct the primary pion energy. The implementation of a software compensation reconstruction developed for this analysis aims to distinguish electromagnetic sub-shower depositions in hadronic showers by the deposited energy in each hit. The implementation differs from a previous software compensation scheme used within CALICE by forcing less dependencies on the shapes of the optimised weights, increasing the number of free parameters but ultimately resulting in a more stable parameter optimisation. The software compensation reconstruction improves the energy resolution of data events by 10% to 20%. Applying the software compensation weights obtained from simulations to data events yields a similar performance compared to the native data weights, slightly degrading the response linearity while even slightly improving the energy resolution. The calorimeter prototypes used in the testbeam analysis presented in this thesis were built to prove the general feasibility of high granularity scintillator-SiPM calorimeters, which they fully accomplished. To demonstrate the scalability of such calorimeters to the size and requirements of a full-scale particle physics experiment as ILD, second generation prototypes with fully integrated readout electronics are developed within the CALICE collaboration. A toy simulation study performed for this thesis shows that the development of scintillator-SiPM tile systems should target a lightyield of 15 (px)/(MIP) in order to maintain a 95% MIP efficiency even for 2σ outliers, when assuming a hit energy threshold of 0.5 MIP. An efficient method to extract and validate trigger thresholds positions for all cells of the detector system is presented, requiring

  17. Design and test of a scintillation dosimeter for dosimetry measurements of high energy radiotherapy beams

    International Nuclear Information System (INIS)

    Fontbonne, J.M.

    2002-12-01

    This work describes the design and evaluation of the performances of a scintillation dosimeter developed for the dosimetry of radiation beams used in radiotherapy. The dosimeter consists in a small plastic scintillator producing light which is guided by means of a plastic optical fiber towards photodetectors. In addition to scintillation, high energy ionizing radiations produce Cerenkov light both in the scintillator and the optical fiber. Based on a wavelength analysis, we have developed a deconvolution technique to measure the scintillation light in the presence of Cerenkov light. We stress the advantages that are anticipated from plastic scintillator, in particular concerning tissue or water equivalence (mass stopping power, mass attenuation or mass energy absorption coefficients). We show that detectors based on this material have better characteristics than conventional dosimeters such as ionisation chambers or silicon detectors. The deconvolution technique is exposed, as well as the calibration procedure using an ionisation chamber. We have studied the uncertainty of our dosimeter. The electronics noise, the fiber transmission, the deconvolution technique and the calibration errors give an overall combined experimental uncertainty of about 0,5%. The absolute response of the dosimeter is studied by means of depth dose measurements. We show that absolute uncertainty with photons or electrons beams with energies ranging from 4 MeV to 25 MeV is less than ± 1 %. Last, at variance with other devices, our scintillation dosimeter does not need dose correction with depth. (author)

  18. Scintillation properties of quantum-dot doped styrene based plastic scintillators

    International Nuclear Information System (INIS)

    Park, J.M.; Kim, H.J.; Hwang, Y.S.; Kim, D.H.; Park, H.W.

    2014-01-01

    We fabricated quantum-dot doped plastic scintillators in order to control the emission wavelength. We studied the characterization of the quantum-dots (CdSe/ZnS) and PPO (2, 5-diphenyloxazole) doped styrene based plastic scintillators. PPO is usually used as a dopant to enhance the scintillation properties of organic scintillators with a maximum emission wavelength of 380 nm. In order to study the scintillation properties of the quantum-dots doped plastic scintillators, the samples were irradiated with X-ray, photon, and 45 MeV proton beams. We observed that only PPO doped plastic scintillators shows a luminescence peak around 380 nm. However, both the quantum-dots and PPO doped plastic scintillators shows luminescence peaks around 380 nm and 520 nm. Addition of quantum-dots had shifted the luminescence spectrum from 380 nm (PPO) toward the region of 520 nm (Quantum-dots). Emissions with wavelength controllable plastic scintillators can be matched to various kinds of photosensors such as photomultiplier tubes, photo-diodes, avalanche photo-diodes, and CCDs, etc. Also quantum-dots doped plastic scintillator, which is irradiated 45 MeV proton beams, shows that the light yield of quantum-dots doped plastic scintillator is increases as quantum-dots doping concentration increases at 520 nm. And also the plastic scintillators were irradiated with Cs-137 γ-ray for measuring fluorescence decay time. -- Highlights: • Quantum-dot doped plastic scintillator is grown by the thermal polymerization method. • Quantum-dot doped plastic scintillators can control the emission wavelength to match with photo-sensor. • Quantum-dots and PPO doped plastic scintillators emitted luminescence peaks around 380 nm and 520 nm. • We observed the energy transfer from PPO to quantum-dot in the quantum-dot doped plastic scintillator

  19. Scintillation properties of quantum-dot doped styrene based plastic scintillators

    Energy Technology Data Exchange (ETDEWEB)

    Park, J.M.; Kim, H.J., E-mail: hongjooknu@gmail.com; Hwang, Y.S.; Kim, D.H.; Park, H.W.

    2014-02-15

    We fabricated quantum-dot doped plastic scintillators in order to control the emission wavelength. We studied the characterization of the quantum-dots (CdSe/ZnS) and PPO (2, 5-diphenyloxazole) doped styrene based plastic scintillators. PPO is usually used as a dopant to enhance the scintillation properties of organic scintillators with a maximum emission wavelength of 380 nm. In order to study the scintillation properties of the quantum-dots doped plastic scintillators, the samples were irradiated with X-ray, photon, and 45 MeV proton beams. We observed that only PPO doped plastic scintillators shows a luminescence peak around 380 nm. However, both the quantum-dots and PPO doped plastic scintillators shows luminescence peaks around 380 nm and 520 nm. Addition of quantum-dots had shifted the luminescence spectrum from 380 nm (PPO) toward the region of 520 nm (Quantum-dots). Emissions with wavelength controllable plastic scintillators can be matched to various kinds of photosensors such as photomultiplier tubes, photo-diodes, avalanche photo-diodes, and CCDs, etc. Also quantum-dots doped plastic scintillator, which is irradiated 45 MeV proton beams, shows that the light yield of quantum-dots doped plastic scintillator is increases as quantum-dots doping concentration increases at 520 nm. And also the plastic scintillators were irradiated with Cs-137 γ-ray for measuring fluorescence decay time. -- Highlights: • Quantum-dot doped plastic scintillator is grown by the thermal polymerization method. • Quantum-dot doped plastic scintillators can control the emission wavelength to match with photo-sensor. • Quantum-dots and PPO doped plastic scintillators emitted luminescence peaks around 380 nm and 520 nm. • We observed the energy transfer from PPO to quantum-dot in the quantum-dot doped plastic scintillator.

  20. Fine-granularity electromagnetic calorimeter using plastic scintillator strip-array

    International Nuclear Information System (INIS)

    Nagano, A.; Yamauchi, S.; Matsunaga, H.; Kim, S.; Matsumoto, T.; Sekiguchi, K.; Uchida, N.; Yamada, Y.; Yamamoto, S.; Evtoukhovitch, P.; Fujii, Y.; Garutti, E.; Iba, S.; Itoh, S.; Kajino, F.; Kalinnikov, V.; Kallies, W.; Kanzaki, J.; Kawagoe, K.; Kishimoto, S.; Miyata, H.; Mzavia, D.; Nakajima, N.; Nakamura, R.; Ono, H.; Samoilov, V.; Sanchez, A.L.C.; Takeshita, T.; Tamura, Y.; Tsamalaidze, Z.

    2006-01-01

    For the future linear collider calorimetry, fine-granularity is indispensable for energy measurements based on particle flow algorithm, which could achieve better energy resolution for jets than the conventional method. To explore the possibility for such a calorimeter using scintillator, an electromagnetic calorimeter test module, made of scintillator-strips and lead plates, was constructed and tested with test beams. Performance of the test module is presented in this article, in terms of the shower profile studies as well as energy and spatial measurements

  1. Development of an ICCD-scintillator system for measurement of spatial dose distributions around 'hot particles'

    International Nuclear Information System (INIS)

    Aydarous, A. Sh; Darley, P. J.; Charles, M. W.

    2004-01-01

    An intensified charge coupled device (ICCD)-scintillator system has been investigated for potential use in measuring the spatially non-uniform dose distribution around 'hot particles'. This imaging system is capable of producing real-time measurements considerably quicker than other presently available radiation dosimetry techniques and exhibits good linearity and reproducibility and relatively high spatial resolution (∼17.5 μm). The time required for a dose evaluation is less than a hundredth that required for radiochromic dye film measurements. The non-uniformity of the system has been eliminated by applying pixel-to-pixel correction factors. The measurable dose rate range using a 110 μm thick scintillator extends from ∼2000 down to ∼6 Gy h -1 . The prototype ICCD-scintillator system has been used in evaluation of the skin dose from some high-activity nuclear fuel fragments. The results agree within a few percentage with radiochromic dye film measurements for 1 cm 2 averaging areas. (authors)

  2. An alpha particle detector based on a GPS mosaic scintillator plate for continuous air monitoring in plutonium handling facilities

    International Nuclear Information System (INIS)

    Kaneko, Junichi H.; Izaki, Kenji; Toui, Kouhei; Shimaoka, Takehiro; Morishita, Yuki; Tsubota, Youichi; Higuchi, Mikio

    2016-01-01

    An alpha particle detector was developed for continuous air monitoring of radioactive contamination in working chambers at plutonium handling facilities. A 5-cm-square Gd 2 Si 2 O 7 :Ce (cerium-doped gadolinium pyro-silicate, GPS:Ce) mosaic scintillator plate for alpha particle measurements was fabricated from GPS single-crystal grains of around 550 μm diameter; the GPS grains were made of a GPS polycrystalline body grown using a top seeded solution method. The scintillator layer thickness was approximately 100 μm. The surface filling rate of the GPS grains was ca. 62%. To suppress the influence of non-uniformity of pulse heights of a photomultiplier tube, a central part of ∅ 40 mm of a 76-mm-diameter photomultiplier tube was used. In addition, 3 mm thick high-transmission glass was used as a substrate of the scintillator plate. The detector achieved energy resolution of 13% for 5.5 MeV alpha particles, detection efficiency of 61% and a radon progeny nuclide reduction ratio of 64.5%. A new alpha particle detector was developed to achieve a high radon progeny nuclide reduction ratio approaching that of a silicon semiconductor detector, with high resistance to electromagnetic noise and corrosion. - Highlights: • An alpha particle detector was developed for continuous air monitoring. • The detector comprises a mosaic scintillator plate and a photomultiplier tube. • A 5-cm-square GPS mosaic scintillator plate was fabricated. • Its respective energy resolution and detection efficiency were 13 and 61%. • The radon progeny nuclide reduction ratio of the developed detector was 64.5%.

  3. Scintillator structures

    International Nuclear Information System (INIS)

    Cusano, D.A.; Prener, J.S.

    1978-01-01

    Distributed phosphor scintillator structures providing superior optical coupling to photoelectrically responsive devices together with methods for fabricating said scintillator structures are disclosed. In accordance with one embodiment of the invention relating to scintillator structures, the phosphor is distributed in a 'layered' fashion with certain layers being optically transparent so that the visible wavelength output of the scintillator is better directed to detecting devices. In accordance with another embodiment of the invention relating to scintillator structures, the phosphor is distributed throughout a transparent matrix in a continuous fashion whereby emitted light is more readily transmitted to a photodetector. Methods for fabricating said distributed phosphor scintillator structures are also disclosed. (Auth.)

  4. High spectral resolution studies of gamma ray bursts on new missions

    International Nuclear Information System (INIS)

    Desai, U. D.; Acuna, M. H.; Cline, T. L.; Dennis, B. R.; Orwig, L. E.; Trombka, J. I.; Starr, R. D.

    1996-01-01

    Two new missions will be launched in 1996 and 1997, each carrying X-ray and gamma ray detectors capable of high spectral resolution at room temperature. The Argentine Satelite de Aplicaciones Cientificas (SAC-B) and the Small Spacecraft Technology Initiative (SSTI) Clark missions will each carry several arrays of X-ray detectors primarily intended for the study of solar flares and gamma-ray bursts. Arrays of small (1 cm 2 ) cadmium zinc telluride (CZT) units will provide x-ray measurements in the 10 to 80 keV range with an energy resolution of ≅6 keV. Arrays of both silicon avalanche photodiodes (APD) and P-intrinsic-N (PIN) photodiodes (for the SAC-B mission only) will provide energy coverage from 2-25 keV with ≅1 keV resolution. For SAC-B, higher energy spectral data covering the 30-300 keV energy range will be provided by CsI(Tl) scintillators coupled to silicon APDs, resulting in similar resolution but greater simplicity relative to conventional CsI/PMT systems. Because of problems with the Pegasus launch vehicle, the launch of SAC-B has been delayed until 1997. The launch of the SSTI Clark mission is scheduled for June 1996

  5. Highly lead-loaded red plastic scintillators as an X-ray imaging system for the laser Mega Joule

    International Nuclear Information System (INIS)

    Hamel, Matthieu; Normand, Stephane; Turk, Gregory; Darbon, Stephane

    2012-01-01

    The scope of this project intends to record spatially resolved images of core shape and size of a deuterium-tritium micro-balloon during inertial confinement fusion (ICF) experiments at Laser Mega Joule facility (LMJ). We need to develop an x-ray imaging system which can operate in the hard radiative background generated by an ignition shot of ICF. The scintillator is a part of the imaging system and has to gather a compromise of scintillating properties (scintillating efficiency, decay time, emission wavelength) so as to both operate in the hard radiative environment and to allow the acquisition of spatially resolved images. Inorganic scintillators cannot be used because no compromise can be found regarding the expected scintillating properties. Most of them are not fast enough and emit blue light. Organic scintillators are generally fast, but present low x-ray photoelectric absorption in the 10 to 40 keV range. This does not enable the acquisition of spatially resolved images. To this aim, we have developed highly lead-loaded and red-fluorescent fast plastic scintillators. Such a combination is not currently available via scintillator suppliers, since they propose only blue-fluorescent plastic scintillators doped with up to 12 wt% Pb. Thus, incorporation ratio up to 27 wt% Pb has been reached in our laboratory, which can afford a plastic scintillator with an outstanding Z(eff) close to 50. X-rays in the 10 to 40 keV range can thus interact with a higher probability of photoelectric effect than for classic organic scintillators, such as NE-102. The strong orange-red fluorescence can be filtered, so that we can eliminate residual Cerenkov light, generated by gamma-ray absorption in glass parts of the imaging system. Characteristic decay times of our scintillators evaluated under UV excitation were estimated to be in the range 10 to 13 ns. (authors)

  6. A fast, high light output scintillator for gamma ray and neutron detection. Fifth Semi-Annual Report

    International Nuclear Information System (INIS)

    Entine, Gerald; Kanai, S.; Shah, M.S.; Leonard Cirignano, M.S.; Jarek Glodo; Van Loef, Edgar V.

    2003-01-01

    In view of the attractive properties of RbGd2Br7:Ce for gamma-ray and thermal neutron detection, and the lack of larger volume crystals, the goal of the Phase I project was to perform a rigorous investigation of the crystal growth of this exciting material and explore its capabilities for gamma-ray and thermal neutron detection. The Phase I research was very successful. All technical objectives were met and in many cases exceeded expectations. We were able to produce large (>1 cm3) RbGd2Br7:Ce crystals with excellent scintillation properties and demonstrated the possibility to detect thermal neutrons. As far as we are aware, our Phase I experiment was the first to demonstrate thermal neutron detection with RbGd2Br7:Ce. Clearly, the feasibility of the proposed research was adequately proven. The Phase II research builds on the successful results obtained during Phase I. Phase II will initially focus on optimizing the RbGd2Br7:Ce growth process to produce high quality, larger volume RbGd2Br7:Ce crystals. We will continue to use the versatile Bridgman technique. During this process, crystal growth parameters will be adjusted for optimal growth conditions. Our goal is to produce high quality RbGd2Br7:Ce crystals of size 1 inch x 1 inch x 1 inch (∼16 cm3). We will work on packaging aspects that allow efficient light collection and prevent crystal degradation. We will study and measure emission spectra, light yield, scintillation decay, energy and time resolution. The effects of variation in Ce concentration on the scintillation properties of RbGd2Br7:Ce will be examined in detail. Comprehensive gamma-ray spectroscopic and imaging studies will be conducted. Also, optimization of RbGd2Br7:Ce for thermal neutron detection will be addressed. Our initial studies will determine the optimal geometry of the RbGd2Br7:Ce crystals for neutron detection. For thermal neutron detection experiments, we will produce large area, thin samples in order to minimize gamma-ray sensitivity

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-05-15

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

  8. Evaluation of dual γ-ray imager with active collimator using various types of scintillators.

    Science.gov (United States)

    Lee, Wonho; Lee, Taewoong; Jeong, Manhee; Kim, Ho Kyung

    2011-10-01

    The performance of a specialized dual γ-ray imager using both mechanical and electronic collimation was evaluated by Monte Carlo simulation (MCNP5). The dual imager consisted of an active collimator and a planar detector that were made from scintillators. The active collimator served not only as a coded aperture for mechanical collimation but also as a first detector for electronic collimation. Therefore, a single system contained both mechanical and electronic collimation. Various types of scintillators were tested and compared with each other in terms of their angular resolution, efficiency, and background noise. In general, a BGO active collimator had the best mechanical collimation performance, and an LaCl₃(Ce) active collimator provided the best electronic collimation performance. However, for low radiation energies, the mechanical collimation images made from both scintillators showed the same quality, and, for high radiation energies, electronic collimation images made from both scintillators also show similar quality. Therefore, if mechanical collimation is used to detect low-energy radiation and electronic collimation is applied to reconstruct a high-energy source, either LaCl₃(Ce) or BGO would be appropriate for the active collimator of a dual γ-ray imager. These results broaden the choice of scintillators for the active collimator of the dual γ-ray imager, which makes it possible to consider other factors, such as machinability and cost, in making the imager. As a planar detector, BGO showed better performance than other scintillators since its radiation detection efficiency was highest of all. Copyright © 2011 Elsevier Ltd. All rights reserved.

  9. Liquid scintillation solutions

    International Nuclear Information System (INIS)

    Long, E.C.

    1976-01-01

    The liquid scintillation solution described includes a mixture of: a liquid scintillation solvent, a primary scintillation solute, a secondary scintillation solute, a variety of appreciably different surfactants, and a dissolving and transparency agent. The dissolving and transparency agent is tetrahydrofuran, a cyclic ether. The scintillation solvent is toluene. The primary scintillation solute is PPO, and the secondary scintillation solute is dimethyl POPOP. The variety of appreciably different surfactants is composed of isooctylphenol-polyethoxyethanol and sodium dihexyl sulphosuccinate [fr

  10. Preliminary study of light yield dependence on LAB liquid scintillator composition

    International Nuclear Information System (INIS)

    Ye Xingchen; Yu Boxiang; Zhou Xiang

    2015-01-01

    Liquid scintillator (LS) will be adopted as the detector material in JUNO (Jiangmen Underground Neutrino Observatory). The energy resolution requirement of JUNO is 3%, which has never previously been reached. To achieve this energy resolution, the light yield of liquid scintillator is an important factor. PPO (the fluor) and bis-MSB (the wavelength shifter) are the two main materials dissolved in LAB. To study the influence of these two materials on the transmission of scintillation photons in LS, 25 and 12 cm-long quartz vessels were used in a light yield experiment. LS samples with different concentration of PPO and bis-MSB were tested. At these lengths, the light yield growth is not obvious when the concentration of PPO is higher than 4 g/L. The influence from bis-MSB becomes insignificant when its concentration is higher than 8 mg/L. This result could provide some useful suggestions for the JUNO LS. (authors)

  11. Test of a large size acrylic scintillation counter

    International Nuclear Information System (INIS)

    Bertino, M.; De Zorzi, G.; Zanello, D.

    1984-01-01

    We have tested the behaviour of an acrylic scintillator measuring the attenuation length and the time resolution of a 7.8 m long counter. On a small sample the photon yield relative to the NE 110 plastic has been measured. (orig.)

  12. Extruded plastic scintillator for MINERvA

    International Nuclear Information System (INIS)

    Pla-Dalmau, Anna; Bross, Alan D.; FermilabRykalin, Victor V.; Wood, Brian M.; NICADD, DeKalb

    2005-01-01

    An extrusion line has recently been installed at Fermilab in collaboration with NICADD (Northern Illinois Center for Accelerator and Detector Development). This new facility will serve to further develop and improve extruded plastic scintillator. Since polystyrene is widely used in the consumer industry, the logical path was to investigate the extrusion of commercial-grade polystyrene pellets with dopants to yield high quality plastic scintillator. The D0 and MINOS experiments are already using extruded scintillator strips in their detectors. A new experiment at Fermilab is pursuing the use of extruded plastic scintillator. A new plastic scintillator strip is being tested and its properties characterized. The initial results are presented here

  13. Compensation Methods for Non-uniform and Incomplete Data Sampling in High Resolution PET with Multiple Scintillation Crystal Layers

    International Nuclear Information System (INIS)

    Lee, Jae Sung; Kim, Soo Mee; Lee, Dong Soo; Hong, Jong Hong; Sim, Kwang Souk; Rhee, June Tak

    2008-01-01

    To establish the methods for sinogram formation and correction in order to appropriately apply the filtered backprojection (FBP) reconstruction algorithm to the data acquired using PET scanner with multiple scintillation crystal layers. Formation for raw PET data storage and conversion methods from listmode data to histogram and sinogram were optimized. To solve the various problems occurred while the raw histogram was converted into sinogram, optimal sampling strategy and sampling efficiency correction method were investigated. Gap compensation methods that is unique in this system were also investigated. All the sinogram data were reconstructed using 2D filtered backprojection algorithm and compared to estimate the improvements by the correction algorithms. Optimal radial sampling interval and number of angular samples in terms of the sampling theorem and sampling efficiency correction algorithm were pitch/2 and 120, respectively. By applying the sampling efficiency correction and gap compensation, artifacts and background noise on the reconstructed image could be reduced. Conversion method from the histogram to sinogram was investigated for the FBP reconstruction of data acquired using multiple scintillation crystal layers. This method will be useful for the fast 2D reconstruction of multiple crystal layer PET data

  14. A miniature gamma ray dosimeter with CWO scintillator and plastic optical fiber combination

    International Nuclear Information System (INIS)

    Jae Woo Park, Min Woo Seo

    2008-01-01

    Full text: Fiber-optic scintillation dosimeters possess several favorable characteristics, such as remote measurability and superior spatial resolution. Such a radiation dosimeter model was developed by attaching a small piece of CWO (CdWO 4 ) scintillator to a low attenuation plastic optical fiber. CWO was chosen since the higher atomic numbers of Cd and W would render the size of the scintillator smaller. The size of the scintillator was 4.7x4.7x10 mm 3 . The scintillator was optically glued to the plastic optical fiber of 3 mm diameter and 10 m length. A current-type PMT was optically coupled to the other end of the fiber to convert the lights generated in the scintillator into current signals. The dosimeter model was tested with two 60 Co standard sources of 0.5 mCi and 1 mCi to measure the PMT current as a function of the source-to-detector distance. It was then tested in a 60 Co irradiation chamber with an activity of about 6600 Ci. MCNPX simulations were performed for the source and detector arrangements to calculate the deposited energy in the CWO scintillator. The profiles of the measured current change are compared with those of the calculated energy deposition change. While there is some deviation between the measured and calculated profiles obtained with the lower-activity standard sources, the measured profile accurately coincides with the calculated one obtained in the higher-activity irradiation chamber. This study suggests that the fiber-optic scintillation dosimeter, operated in current mode, can be used to remotely measure radiation doses in high-intensity gamma fields

  15. Scintillating ribbon x-ray detector

    International Nuclear Information System (INIS)

    Kinchen, B.E.; Rogers, A.

    1995-01-01

    A patent in the early 1970's by Aerojet Corporation in Sacramento, CA put forth the idea of using an array of scintillating fibers for x-ray detection and imaging. In about 1975, Pratt and Whitney Aircraft in East Hartford, CT designed and manufactured an imaging system based on the patent. The device was 1.75 in thick in the direction of the x-ray beam and about 4 in. by 4 in. square. The device was used with a 8 MeV x-ray source to image and measure internal clearances within operating aircraft, gas turbines engines. There are significant advantages of fiber optic detectors in x-ray detection. However, the advantages are often outweighed by the disadvantages. Two of the advantages of scintillating fiber optic x-ray detectors are: (1) high limiting spatial frequency -- between 20 and 25 lp/mm; and (2) excellent x-ray stopping power -- they can be made thick and retain spatial resolution. In traditional fiber optic detectors the x-rays are oriented parallel to the long axis of the fiber. For the scintillating ribbon x-ray sensor, the x-rays are oriented normal to the fiber long axis. This ribbon sensor technique has a number of advantages over the two current radiographic techniques digital x-radiography and x-ray film: The main advantage the ribbon has is size and shape. It can be as thin as 0.05 in., virtually any width or length, and flexible. Once positioned in a given location, 20 to 100 square inches of the object being inspected can be imaged with a single x-ray beam sweep. It is clear that conventional digital cameras do not lend themselves to placement between walls of aircraft structures or similar items requiring x-ray inspections. A prototype scintillating ribbon x-ray sensor has been fabricated and tested by Synergistic Detector Designs. Images were acquired on corrosion test panels of aluminum fabricated by Iowa State University

  16. A High Resolution Phoswich Detector: LaBr3(Ce) Coupled With LaCl3(Ce)

    Science.gov (United States)

    Carmona-Gallardo, M.; Borge, M. J. G.; Briz, J. A.; Gugliermina, V.; Perea, A.; Tengblad, O.; Turrión, M.

    2010-04-01

    An innovative solution for the forward end-cap CALIFA calorimeter of R3B is under investigation consisting of two scintillation crystals, LaBr3 and LaCl3, stacked together in a phoswich configuration with one readout only. This dispositive should be capable of a good determination of the energy of protons and gamma radiation. This composite detector allows to deduce the initial energy of charged particles by ΔE1+ΔE2 identification. For gammas, the simulations show that there is a high probability that the first interaction occurs inside the scintillator at few centimeters, with a second layer, the rest of the energy is absorbed, or it can be used as veto event in case of no deposition in the first layer. One such a detector has been tested at the Centro de MicroAnálisis de Materiales (CMAM) in Madrid. Good resolution and time signal separation have been achieved.

  17. Optimization of the scintillation parameters of the lead tungstate crystals for their application in high precision electromagnetic calorimetry

    International Nuclear Information System (INIS)

    Drobychev, G.

    2000-01-01

    In the frame of this dissertation work scintillation properties of the lead tungstate crystals PWO) and possibilities of their use were studied foreseeing their application for electromagnetic calorimetry in extreme radiation environment conditions of new colliders. The results of this work can be summarized in the following way. 1. A model of the scintillations origin in the lead tungstate crystals which includes processes influencing on the crystals radiation hardness and presence of slow components in scintillations was developed. 2. An analysis of the influences of the PWO scintillation properties changes on the parameters of the electromagnetic calorimeter was done. 3. Methods of the light collection from the large scintillation elements of complex shape made of the birefringent scintillation crystal with high refraction index and low light yield in case of signal registration by a photodetector with sensitive surface small in compare with the output face of scintillator were Studied. 4. Physical principles of the methodology of the scintillation crystals certification during their mass production foreseeing their installation into a calorimeter electromagnetic were developed. Correlations between the results of measurements of the PWO crystals parameters by different methods were found. (author)

  18. New prototype scintillator detector for the Tibet ASγ experiment

    Science.gov (United States)

    Zhang, Y.; Gou, Q.-B.; Cai, H.; Chen, T.-L.; Danzengluobu; Feng, C.-F.; Feng, Y.-L.; Feng, Z.-Y.; Gao, Q.; Gao, X.-J.; Guo, Y.-Q.; Guo, Y.-Y.; Hou, Y.-Y.; Hu, H.-B.; Jin, C.; Li, H.-J.; Liu, C.; Liu, M.-Y.; Qian, X.-L.; Tian, Z.; Wang, Z.; Xue, L.; Zhang, X.-Y.; Zhang, Xi-Ying

    2017-11-01

    The hybrid Tibet AS array was successfully constructed in 2014. It has 4500 m2 underground water Cherenkov pools used as the muon detector (MD) and 789 scintillator detectors covering 36900 m2 as the surface array. At 100 TeV, cosmic-ray background events can be rejected by approximately 99.99%, according to the full Monte Carlo (MC) simulation for γ-ray observations. In order to use the muon detector efficiently, we propose to extend the surface array area to 72900 m2 by adding 120 scintillator detectors around the current array to increase the effective detection area. A new prototype scintillator detector is developed via optimizing the detector geometry and its optical surface, by selecting the reflective material and adopting dynode readout. {This detector can meet our physics requirements with a positional non-uniformity of the output charge within 10% (with reference to the center of the scintillator), time resolution FWHM of ~2.2 ns, and dynamic range from 1 to 500 minimum ionization particles}.

  19. A scintillating fibre detector for the Crystal Barrel experiment at ELSA

    International Nuclear Information System (INIS)

    Suft, G.; Anton, G.; Bogendoerfer, R.; Ehmanns, A.; Foesel, A.; Hoessl, J.; Kalinowsky, H.; Kueppersbusch, C.; Walther, D.

    2005-01-01

    A scintillating fibre detector with high spatial granularity was built for the Crystal Barrel experiment at ELSA (CB-ELSA) in Bonn. It consists of 513 scintillating fibres with 2mm in diameter, arranged in three layers with cylindrical geometry inside the Crystal Barrel detector surrounding the target cell. Two layers are wound in opposite directions, the third is parallel to the incident beam direction, resulting in an unambiguous hit reconstruction and a position resolution better than 1.6mm for charged particles. The read-out is done with 16-channel multi-anode photomultipliers. The detector was designed to cover the full angular acceptance of the Crystal Barrel detector with an angular range of 12 deg. ≤θ = 168 deg. and 0 deg. ≤φ≤360 deg. in the lab frame

  20. Search for and selection of novel heavy scintillator crystals for calorimeter design for future high-energy colliders

    International Nuclear Information System (INIS)

    Ferrere, D.

    1993-01-01

    The discovery of some particles (Higgs, top,..) foreseen by theoretical models should be achieved at future colliders allowing to reach an energy scale of about 1 TeV. Efficient detectors must be designed to handle the very high luminosity of the LHC collider at CERN. In the intermediate mass region, M Z -2M Z , the diphoton decay mode of a Higgs boson produced inclusively or in association with W boson or a toponium gives good chance of observation. A very high resolution calorimeter with photon angle reconstruction and pion identification capability should detect a Higgs signal with high probability. So a homogeneous crystal calorimeter seems to be suitable. Because of the high luminosity and the high radiation level, a search for a new heavy scintillator has been undertaken. It must have a good radiation hardness (>0.5 MRad in a year) and a fast luminescence decay time (<30 ns). Among 50 crystals or glasses of specific chemical composition tested in transmission, luminescence, decay time, γ/neutrons radiation and light yield, cerium fluoride seems best suited for LHC. The necessity to have a good photon resolution in the intermediate Higgs mass region led us to optimise by Monte Carlo simulations the geometry of the calorimeter, the uniformisation of the light collection and crystal intercalibration parameters. (orig.)

  1. The quest for the ideal inorganic scintillator

    International Nuclear Information System (INIS)

    Derenzo, S.E.; Weber, M.J.; Bourret-Courchesne, E.; Klintenberg, M.K.

    2002-01-01

    The past half century has witnessed the discovery of many new inorganic scintillator materials and numerous advances in our understanding of the basic physical processes governing the transformation of ionizing radiation into scintillation light. Whereas scintillators are available with a good combination of physical properties, none provides the desired combination of stopping power, light output, and decay time. A review of the numerous scintillation mechanisms of known inorganic scintillators reveals why none of them is both bright and fast. The mechanisms of radiative recombination in wide-bandgap direct semiconductors, however, remain relatively unexploited for scintillators. We describe how suitably doped semiconductor scintillators could provide a combination of high light output, short decay time, and linearity of response that approach fundamental limits

  2. Application of avalanche photodiodes for the measurement of actinides by alpha liquid scintillation counting

    International Nuclear Information System (INIS)

    Reboli, A.

    2005-10-01

    Alpha emitters analysis using liquid scintillation spectroscopy is often used when sensitivity and fast samples preparation are the important points. A more extensive use of this technique is until now limited by its poor resolution compared to alpha particle spectroscopy with semiconductor detectors. To improve the resolution and thus promote this method for the measurement of actinides in environment, we have tested silicon avalanche photodiodes (APD) as new detectors for scintillation photons. The set-up consists of a large area avalanche photodiode (16 mm diameter) coupled to a thin vial containing alpha-emitters within a liquid scintillation cocktail. After optimization of several parameters like bias voltage, temperature, counting geometry and composition of the scintillating cocktail, energy resolutions have been found to be better than those obtained with standard photomultiplier tubes (PMT): 5% (200 keV FWHM) for 232 Th and 4.2% (240 keV FWHM) for 236 Pu. Our results show that the improvement is due to less fluctuations associated with light collection since the spatial response of APDs is more uniform than that of PMTs. The expected gain on quantum efficiency (80% for APDs instead of 25% for PMTs) is nullified by a corresponding increase on electronic noise and excess noise factor. Significant better results are foreseen by using green scintillators (450 - 550 nm wavelengths region) with larger Stokes-shift and blue-enhanced APDs which reach their maximum quantum efficiency in this region. (author)

  3. Liquid xenon/krypton scintillation calorimeter

    International Nuclear Information System (INIS)

    Akimov, D.Yu.; Bolozdynya, A.I.; Brastilov, A.D.

    1994-01-01

    A scintillating LXe/LKr electromagnetic calorimeter has been built at the ITEP and tested at the BATES (MIT) accelerator. The detector consists of PMT matrix and 45 light collecting cells made of aluminized 50 microns Mylar partially covered with p-terphenyl as a wavelength-shifter. Each pyramidal cell has (2.1 x 2.1) x 40 x (4.15 x 4.15) cm dimensions and is viewed by FEU-85 glass-window photomultiplier. The detector has been exposed at 106-348 MeV electron beam. The energy resolution σ E /E ≅ 5% √ E at 100 - 350 MeV range in LXe, the coordinate resolution τ x ≅ 0.7 cm, the time resolution for single cell ≅ 0.6 ns have been obtained. Possible ways to improve energy resolution are discussed. 8 refs., 15 figs

  4. On the possibility of improving the amplitude-time characteristics of the BDEhG2-39 scintillator block

    International Nuclear Information System (INIS)

    Berestov, A.V.; Zyazyulya, F.E.

    1983-01-01

    Changes in the energy resolution, voltage amplitUde output anode pulse rise time and duration of the BDEhG2-39 serial scintillator on the base of a 150x100 mm NaI(Tl) crystal and photomultiplier FEhU-49B (PM) with the use of different voltage dividers and techniques of high-voltage power supply to the PM are investigated. Three methods of high-voltage power supply to the scintillator block are investigated: 1) the photocathode and the body are grounded, positive polarity high-voltage is supplied to the anode (through anode loading resistance); 2) the anode and the body are grounded, negative polarity high-voltage power is supplied to the photocathode; 3) the anode is grounded, negative polarity high-voltage power is sUpplied to the photocathode and body of the scintillator block. It is shown that connection of the focusing electrode to the first dinode decreases the output pulse front rise time 2-2.5 times and its duration by 30%. It is concluded that the best performance is assured by grounding the PM photocathode and body

  5. Scintillation properties of acrylate based plastic scintillator by photoploymerization method

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sung Hwan [Dept. of Radiological Science, Cheongju University, Cheongju (Korea, Republic of); Lee, Joo Il [Dept. of of Radiology, Daegu Health College, Daegu (Korea, Republic of)

    2016-12-15

    In this study, we prepared and characterized a acrylate based UV-curable plastic scintillator. It was used co-polymers TMPTA, DHPA and Ultima GoldTM LLT organic scintillator. The emission spectrum of the plastic scintillator was located in the range of 380⁓520 nm, peaking at 423 nm. And the scintillator is more than 50% transparent in the range of 400⁓ 800 nm. The emission spectrum is well match to the quantum efficiency of photo-multiplier tube and the fast decay time of the scintillation is 12 ns, approximately. This scintillation material provides the possibility of combining 3D printing technology, and then the applications of the plastic scintillator may be expected in human dosimetry etc.

  6. A new type of a gas scintillating chamber

    International Nuclear Information System (INIS)

    Khoury, H.J.

    1981-01-01

    In a previous paper (H.J. Khoury - thesis - 1978) the author has described a new type of a gas scintillating chamber, in which the light emitted by excitation of the gas, due to the passage of a charged incoming particle, has its intensity increased by the action of an applied electric field. New experiments are described which contribute to a deeper understanding of the phenomena involved in the scintillating chamber due to the nature of the gas, the electric field and spatial distribution, etc.. The behaviour of the gas scintillation counter is studied both in the proportional region and in the region of limited proportionality. It is shown that by the use of a suitable gas mixture and applied electric field, the resolution of an alpha particle spectrum is considerably increased and values up to 0,9% can be attained. (Author) [pt

  7. Improvement of an X-ray imaging detector based on a scintillating guides screen

    CERN Document Server

    Badel, X; Linnros, J; Kleimann, P; Froejdh, C; Petersson, C S

    2002-01-01

    An X-ray imaging detector has been developed for dental applications. The principle of this detector is based on application of a silicon charge coupled device covered by a scintillating wave-guide screen. Previous studies of such a detector showed promising results concerning the spatial resolution but low performance in terms of signal to noise ratio (SNR) and sensitivity. Recent results confirm the wave-guiding properties of the matrix and show improvement of the detector in terms of response uniformity, sensitivity and SNR. The present study is focussed on the fabrication of the scintillating screen where the principal idea is to fill a matrix of Si pores with a CsI scintillator. The photoluminescence technique was used to prove the wave-guiding property of the matrix and to inspect the filling uniformity of the pores. The final detector was characterized by X-ray evaluation in terms of spatial resolution, light output and SNR. A sensor with a spatial resolution of 9 LP/mm and a SNR over 50 has been achie...

  8. Transmission environmental scanning electron microscope with scintillation gaseous detection device

    International Nuclear Information System (INIS)

    Danilatos, Gerasimos; Kollia, Mary; Dracopoulos, Vassileios

    2015-01-01

    A transmission environmental scanning electron microscope with use of a scintillation gaseous detection device has been implemented. This corresponds to a transmission scanning electron microscope but with addition of a gaseous environment acting both as environmental and detection medium. A commercial type of low vacuum machine has been employed together with appropriate modifications to the detection configuration. This involves controlled screening of various emitted signals in conjunction with a scintillation gaseous detection device already provided with the machine for regular surface imaging. Dark field and bright field imaging has been obtained along with other detection conditions. With a progressive series of modifications and tests, the theory and practice of a novel type of microscopy is briefly shown now ushering further significant improvements and developments in electron microscopy as a whole. - Highlights: • Novel scanning transmission electron microscopy (STEM) with an environmental scanning electron microscope (ESEM) called TESEM. • Use of the gaseous detection device (GDD) in scintillation mode that allows high resolution bright and dark field imaging in the TESEM. • Novel approach towards a unification of both vacuum and environmental conditions in both bulk/surface and transmission mode of electron microscopy

  9. Results of the R and D activity on the NOE scintillating fiber calorimeter

    International Nuclear Information System (INIS)

    Demitri, I.

    2001-01-01

    The NOE scintillating fiber calorimeter has undergone four years of intense R and D activity. Measurements of light attenuation and time resolution have been carried out on a variety of commercially available scintillating fibers. Both these parameters are important for the optimisation of the design of the calorimeter which will be part of the ICANOE detector

  10. Results of the R and D activity on the NOE scintillating fiber calorimeter

    Energy Technology Data Exchange (ETDEWEB)

    Demitri, I. E-mail: ivan.demitri@le.infr.it

    2001-04-01

    The NOE scintillating fiber calorimeter has undergone four years of intense R and D activity. Measurements of light attenuation and time resolution have been carried out on a variety of commercially available scintillating fibers. Both these parameters are important for the optimisation of the design of the calorimeter which will be part of the ICANOE detector.

  11. Segmented scintillation detectors with silicon photomultiplier readout for measuring antiproton annihilations

    CERN Document Server

    Sótér, A.; Kobayashi, T.; Barna, D.; Horváth, D.; Hori, M.

    2014-01-01

    The Atomic Spectroscopy and Collisions Using Slow Antiprotons (ASACUSA) experiment at the Antiproton Decelerator (AD) facility of CERN constructed segmented scintillators to detect and track the charged pions which emerge from antiproton annihilations in a future superconducting radiofrequency Paul trap for antiprotons. A system of 541 cast and extruded scintillator bars were arranged in 11 detector modules which provided a spatial resolution of 17 mm. Green wavelength-shifting fibers were embedded in the scintillators, and read out by silicon photomultipliers which had a sensitive area of 1 x 1 mm^2. The photoelectron yields of various scintillator configurations were measured using a negative pion beam of momentum p ~ 1 GeV/c. Various fibers and silicon photomultipliers, fiber end terminations, and couplings between the fibers and scintillators were compared. The detectors were also tested using the antiproton beam of the AD. Nonlinear effects due to the saturation of the silicon photomultiplier were seen a...

  12. Development of hard X-ray spectrometer with high time resolution on the J-TEXT tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Ma, T.K.; Chen, Z.Y., E-mail: zychen@hust.edu.cn; Huang, D.W.; Tong, R.H.; Yan, W.; Wang, S.Y.; Dai, A.J.; Wang, X.L.

    2017-06-01

    A hard X-ray (HXR) spectrometer has been developed to study the runaway electrons during the sawtooth activities and during the runaway current plateau phase on the J-TEXT tokamak. The spectrometer system contains four NaI scintillator detectors and a multi-channel analyzer (MCA) with 0.5 ms time resolution. The dedicated peak detection circuit embedded in the MCA provides a pulse height analysis at count rate up to 1.2 million counts per second (Mcps), which is the key to reach the high time resolution. The accuracy and reliability of the system have been verified by comparing with the hardware integrator of HXR flux. The temporal evolution of HXR flux in different energy ranges can be obtained with high time resolution by this dedicated HXR spectrometer. The response of runaway electron transport with different energy during the sawtooth activities can be studied. The energy evolution of runaway electrons during the plateau phase of runaway current can be obtained. - Highlights: • A HXR spectrometer with high time resolution has been developed on J-TEXT tokamak. • The response of REs transport during the sawtooth activities can be investigated. • The energy evolution of REs following the disruptions can be monitored.

  13. A scintillation detector signal processing technique with active pileup prevention for extending scintillation count rates

    International Nuclear Information System (INIS)

    Wong, W.H.; Li, H.

    1998-01-01

    A new method for processing signals from scintillation detectors is proposed for very high count-rate situations where multiple-event pileups are the norm. This method is designed to sort out and recover every impinging event from multiple-event pileups while maximizing the collection of scintillation signal for every event to achieve optimal accuracy in determining the energy of the event. For every detected event, this method cancels the remnant signals from previous events, and excludes the pileup of signals from following events. With this technique, pileup events can be recovered and the energy of every recovered event can be optimally measured despite multiple pileups. A prototype circuit demonstrated that the maximum count rates have been increased by more than 10 times, comparing to the standard pulse-shaping method, while the energy resolution is as good as that of the pulse shaping (or the fixed integration) method at normal count rates. At 2 x 10 6 events/sec for NaI(Tl), the true counts acquired are 3 times more than the delay-line clipping method (commonly used in fast processing designs) due to events recovered from pileups. Pulse-height spectra up to 3.5 x 10 6 events/sec have been studied

  14. High resolution phoswich gamma-ray imager utilizing monolithic MPPC arrays with submillimeter pixelized crystals

    Science.gov (United States)

    Kato, T.; Kataoka, J.; Nakamori, T.; Kishimoto, A.; Yamamoto, S.; Sato, K.; Ishikawa, Y.; Yamamura, K.; Kawabata, N.; Ikeda, H.; Kamada, K.

    2013-05-01

    We report the development of a high spatial resolution tweezers-type coincidence gamma-ray camera for medical imaging. This application consists of large-area monolithic Multi-Pixel Photon Counters (MPPCs) and submillimeter pixelized scintillator matrices. The MPPC array has 4 × 4 channels with a three-side buttable, very compact package. For typical operational gain of 7.5 × 105 at + 20 °C, gain fluctuation over the entire MPPC device is only ± 5.6%, and dark count rates (as measured at the 1 p.e. level) amount to acrylic light guide measuring 1 mm thick, and with summing operational amplifiers that compile the signals into four position-encoded analog outputs being used for signal readout. Spatial resolution of 1.1 mm was achieved with the coincidence imaging system using a 22Na point source. These results suggest that the gamma-ray imagers offer excellent potential for applications in high spatial medical imaging.

  15. A new digital method for high precision neutron-gamma discrimination with liquid scintillation detectors

    International Nuclear Information System (INIS)

    Nakhostin, M

    2013-01-01

    A new pulse-shape discrimination algorithm for neutron and gamma (n/γ) discrimination with liquid scintillation detectors has been developed, leading to a considerable improvement of n/γ separation quality. The method is based on triangular pulse shaping which offers a high sensitivity to the shape of input pulses, as well as, excellent noise filtering characteristics. A clear separation of neutrons and γ-rays down to a scintillation light yield of about 65 keVee (electron equivalent energy) with a dynamic range of 45:1 was achieved. The method can potentially operate at high counting rates and is well suited for real-time measurements.

  16. Optimum plastic scintillator and optical fiber combination for brachytherapy dosimetry

    International Nuclear Information System (INIS)

    Arnfield, Mark R.; Gaballa, Hani E.; Zwicker, Robert D.; Islam, Quazi; Schmidt-Ullrich, Rupert

    1995-01-01

    Purpose/Objective: There have been several recent reports using plastic scintillators to measure dose in photon and electron beams. External beam measurements agreed well with standard ion chamber dosimetry. This was implemented by using two identical, parallel optical fibers with a small piece of plastic scintillator attached to one. We have constructed a similar device for application to brachytherapy. Brachytherapy dosimetry is a more difficult problem than external beam because of high dose gradients and widely ranging photon energies. Based on detailed spectral measurements, we have designed a dosimeter specifically to meet the unique, stringent needs of brachytherapy. Materials and Methods: The work consisted of two stages. In the first stage, we measured the optical spectra emitted by commercial plastic scintillators and silica core optical fibers in the presence of a 10 Curie iridium 192 HDR source. In the second stage, the spectral information was used to select an optimum combination of scintillator and fiber which were incorporated in the dosimeter. Equipment for the spectral measurements included a 0.1 meter monochromator with a sensitive photomultiplier (PMT) with flat response across the visible. The resolution of spectral scans was 4 nm. The dosimeter was constructed with a 1mm x 3mm piece of plastic scintillator bonded with optical cement to a 0.6 mm diameter silica core optical fiber. A second, identical optical fiber running alongside the first, with no scintillator attached, was used for background subtraction. Two PMTs with high sensitivity in the visible were used at the fiber distal ends. There was a space for an optical filter between the fiber and the PMTs, whose purpose is described below. The PMTs were connected to a differential pair whose output was transferred to a current source for measurement by a standard electrometer. Results: The scintillation spectra of six different types of silica core optical fibers in the presence of the

  17. A novel epitaxially grown LSO-based thin-film scintillator for micro-imaging using hard synchrotron radiation

    Energy Technology Data Exchange (ETDEWEB)

    Douissard, P.A.; Martin, T.; Chevalier, V.; Rack, A. [European Synchrotron Radiat Facil, F-38043 Grenoble, (France); Cecilia, A.; Baumbach, T.; Rack, A. [Karlsruhe Inst Technol ANKA, D-76021 Karlsruhe, (Germany); Couchaud, M. [CEA LETI, F-38054 Grenoble, (France); Dupre, K. [FEE GmbH, D-55743 Idar Oberstein, (Germany); Kuhbacher, M. [Helmholtz Zentrum Berlin Mat and Energie, D-14109 Berlin, (Germany)

    2010-07-01

    The efficiency of high-resolution pixel detectors for hard X-rays is nowadays one of the major criteria which drives the feasibility of imaging experiments and in general the performance of an experimental station for synchrotron-based microtomography and radiography. Here the luminescent screen used for the indirect detection is focused on in order to increase the detective quantum efficiency a novel scintillator based on doped Lu{sub 2}SiO{sub 5} (LSO), epitaxially grown as thin film via the liquid phase epitaxy technique. It is shown that, by using adapted growth and doping parameters as well as a dedicated substrate, the scintillation behaviour of a LSO-based thin crystal together with the high stopping power of the material allows for high-performance indirect X-ray detection. In detail, the conversion efficiency, the radioluminescence spectra, the optical absorption spectra under UV/visible-light and the afterglow are investigated. A set-up to study the effect of the thin-film scintillator's temperature on its conversion efficiency is described as well it delivers knowledge which is important when working with higher photon flux densities and the corresponding high heat load on the material. Additionally, X-ray imaging systems based on different diffraction-limited visible-light optics and CCD cameras using among others LSO-based thin film are compared. Finally, the performance of the LSO thin film is illustrated by imaging a honey bee leg, demonstrating the value of efficient high-resolution computed tomography for life sciences. (authors)

  18. A new plastic scintillator with large Stokes shift

    International Nuclear Information System (INIS)

    Destruel, P.; Taufer, M.

    1989-01-01

    We have developed a new plastic scintillator with the novel characteristic of highly localized light emission; scintillation and wavelength shifting take place within a few tens of micrometers of the primary ionization. The new scintillator consists of a scintillating polymer base [polyvinyl toluene (PVT) or polystyrene (PS)] doped with a single wavelength shifter, 1-phenyl-3-mesityl-2-pyrazoline (PMP), which has an exceptionally large Stokes shift and therefore a comparatively small self-absorption of its emitted light. In other characteristics (e.g. scintillation efficiency and decay time) the performance of the new scintillator is similar to a good quality commercial plastic scintillator such as NE110. (orig.)

  19. Advantages of CaF2 over ZnS in an α-particle scintillation detector

    International Nuclear Information System (INIS)

    Sabol, B.; Schery, S.D.

    1981-01-01

    Results are reported for using a europium-activated calcium fluoride (CaF 2 ) scintillation crystal as a α-particle detector in a two-filter monitor of atmospheric radon. CaF 2 detectors are cheaper and can cover a larger surface area than the higher-resolution solid-state detectors. Compared to ZnS scintillators, the energy resolution for CaF 2 is improved from 3.0 MeV to 1.1 MeV for 4.7 MeV α-particles; however the light output from CaF 2 is considerably lower. It is concluded that a thin CaF 2 crystal is a cost-effective method of improving energy and time resolutions for the two-filter monitor. (U.K.)

  20. Development of an application specific scintimammography detector based on a crystal scintillator array and a PSPMT

    CERN Document Server

    Majewski, S; Goode, A; Kross, B J; Steinbach, D; Weisenberger, A; Williams, M; Wojci, R

    1998-01-01

    We report the results of studies conducted with small field of view scintimammography camera based on a position-sensitive photomultiplier tube (5'' Hamamatsu R3292) and several pixelized crystal scintillator arrays made of YAP, CsI(Na) and NaI(Tl) scintillators. Laboratory tests and pre-clinical phantom studies were conducted to compare and optimize the performances of the prototypes with special emphasis on spatial resolution (approx 2-3mm) and sufficient energy resolution for scatter rejection.

  1. Performance of the CHORUS lead-scintillating fiber calorimeter

    CERN Document Server

    Buontempo, S

    1997-01-01

    We report on the design and performance of the lead-scintillating fiber calorimeter of the CHORUS experiment, which searches for νμ-ντ oscillations in the CERN Wide Band Neutrino beam. Two of the three sectors in which the calorimeter is divided are made of lead and plastic scintillating fibers, and they represent the first large scale application of this technique for combined electromagnetic and hadronic calorimetry. The third sector is built using the sandwich technique with lead plates and scintillator strips and acts as a tail catcher for the hadronic energy flow. From tests performed at the CERN SPS and PS an energy resolution of σ(E)/E=(32.3±2.4)%/E(GeV)+(1.4±0.7)% was measured for pions, and σ(E)/E=(13.8±0.9)%/E(GeV)+(−0.2±0.4)% for electrons.

  2. Arrays of Segmented, Tapered Light Guides for Use With Large, Planar Scintillation Detectors

    Science.gov (United States)

    Raylman, Raymond R.; Vaigneur, Keith; Stolin, Alexander V.; Jaliparthi, Gangadhar

    2015-06-01

    Metabolic imaging techniques can potentially improve detection and diagnosis of cancer in women with radiodense and/or fibrocystic breasts. Our group has previously developed a high-resolution positron emission tomography imaging and biopsy device (PEM-PET) to detect and guide the biopsy of suspicious breast lesions. Initial testing revealed that the imaging field-of-view (FOV) of the scanner was smaller than the physical size of the detector's active area, which could hinder sampling of breast areas close to the chest wall. The purpose of this work was to utilize segmented, tapered light guides for optically coupling the scintillator arrays to arrays of position-sensitive photomultipliers to increase both the active FOV and identification of individual scintillator elements. Testing of the new system revealed that the optics of these structures made it possible to discern detector elements from the complete active area of the detector face. In the previous system the top and bottom rows and left and right columns were not identifiable. Additionally, use of the new light guides increased the contrast of individual detector elements by up to 129%. Improved element identification led to a spatial resolution increase by approximately 12%. Due to attenuation of light in the light guides the detector energy resolution decreased from 18.5% to 19.1%. Overall, these improvements should increase the field-of-view and spatial resolution of the dedicated breast-PET system.

  3. Development of continuous detectors for a high resolution animal PET system

    International Nuclear Information System (INIS)

    Siegel, S.; Cherry, S.R.; Ricci, A.R.; Shao, Y.; Phelps, M.E.

    1995-01-01

    The authors propose a design for a high resolution, gamma-camera style detector that is suitable for use in a positron emission tomograph dedicated to small animal research. Through Monte Carlo simulation the authors modeled the performance of a detector composed of one 76.2 x 76.2 x 8 mm thick LSO crystal coupled to a 3 in. square position sensitive photomultiplier tube (PS-PMT). The authors investigated the effect of optical coupling compounds, surface treatment and dept of interaction on the quantity (efficiency) and distribution (spread) of scintillation photons reaching the photocathode. They also investigated linearization of the position response. The authors propose a PET system consisting of fourteen of these detectors in 2 rings, yielding a 16 cm diameter by 15 cm long tomograph. It would operate in 3-D mode subtending a 68% solid angle to the center. The expected spatial resolution is (≤2 mm), with a system efficiency of ∼ 10% at the center (200 keV lower threshold) and a singles count rate capability of approximately 10 6 cps per detector

  4. Evaluation of various planar gaseous detectors with CsI photocathodes for the detection of primary scintillation light from noble gases

    CERN Document Server

    Periale, L; Carlson, P J; Francke, T; Iacobaeus, C; Pavlopoulos, P; Pietropaolo, F; Sokolova, T

    2003-01-01

    Noble gases and liquids are excellent scintillators and this opens a unique opportunity to directly detect the primary scintillation light produced in these media by photons or particles. This signal can be used for several purposes, for example as a start signal for TPCs or for particles identification. Usually photomultipliers (PMs) are used for the detection of the scintillation light. In our previous work we have demonstrated that costly PMs could be replaced by gaseous detectors with CsI photocathodes . Such detectors have the same quantum efficiency as the best PMs but at the same time are cheap, simple and have high position and time resolutions. The aim of this work is to evaluate various planar type gaseous detectors with CsI photocahodes in order to choose the best one for the detection of the primary scintillation light from noble gases and liquids.

  5. Design of Fluorescent Compounds for Scintillation Detection

    Energy Technology Data Exchange (ETDEWEB)

    Pla-Dalmau, Anna [Northern Illinois U.

    1990-01-01

    Plastic scintillation detectors for high energy physics applications require the development of new fluorescent compounds to meet the demands set by the future generation of particle accelerators such as the Superconducting Supercollider (SSe). Plastic scintillators are commonly based on a polymer matrix doped with two fluorescent compounds: the primary dopant and the wavelength shifter. Their main characteristics are fast response time and high quantum efficiency. The exposure to larger radiation doses and demands for larger light output questions their survivability in the future experiments. A new type of plastic scintillator - intrinsic scintillator - has been suggested. It uses a single dopant as primary and wavelength shifter, and should be less susceptible to radiation damage....

  6. Estimation of Compton Imager Using Single 3D Position-Sensitive LYSO Scintillator: Monte Carlo Simulation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Taewoong; Lee, Hyounggun; Kim, Younghak; Lee, Wonho [Korea University, Seoul (Korea, Republic of)

    2017-07-15

    The performance of a Compton imager using a single three-dimensional position-sensitive LYSO scintillator detector was estimated using a Monte Carlo simulation. The Compton imager consisted of a single LYSO scintillator with a pixelized structure. The size of the scintillator and each pixel were 1.3 × 1.3 × 1.3 cm{sup 3} and 0.3 × 0.3 × 0.3 cm{sup 3}, respectively. The order of γ-ray interactions was determined based on the deposited energies in each detector. After the determination of the interaction sequence, various types of reconstruction algorithms such as simple back-projection, filtered back-projection, and list-mode maximum-likelihood expectation maximization (LM-MLEM) were applied and compared with each other in terms of their angular resolution and signal-tonoise ratio (SNR) for several γ-ray energies. The LM-MLEM reconstruction algorithm exhibited the best performance for Compton imaging in maintaining high angular resolution and SNR. The two sources of {sup 137}Cs (662 keV) could be distinguishable if they were more than 17 ◦ apart. The reconstructed Compton images showed the precise position and distribution of various radiation isotopes, which demonstrated the feasibility of the monitoring of nuclear materials in homeland security and radioactive waste management applications.

  7. Liquid-helium scintillation detection with germanium photodiodes

    International Nuclear Information System (INIS)

    Luke, P.N.; Haller, E.E.; Steiner, H.M.

    1982-05-01

    Special high-purity germanium photodiodes have been developed for the direct detection of vacuum ultraviolet scintillations in liquid helium. The photodiodes are immersed in the liquid helium, and scintillations are detected through one of the bare sides of the photodiodes. Test results with scintillation photons produced by 5.3-MeV α particles are presented. The use of these photodiodes as liquid-helium scintillation detectors may offer substantial improvements over the alternate detection method requiring the use of wavelength shifters and photomultiplier tubes

  8. Liquid scintillation alpha counting and spectrometry and its application to bone and tissue samples

    International Nuclear Information System (INIS)

    McDowell, W.J.; Weiss, J.F.

    1976-01-01

    Three methods for determination of alpha-emitting nuclides using liquid scintillation counting are compared, and the pertinent literature is reviewed. Data showing the application of each method to the measurement of plutonium concentration in tissue and bone samples are presented. Counting with a commercial beta-liquid scintillation counter and an aqueous-phase-accepting scintillator is shown to be accurate only in cases where the alpha activity is high (several hundred counts/min or more), only gross alpha counting is desired, and beta-gamma emitters are known to be absent from the sample or present at low levels compared with the alpha activity. Counting with the same equipment and an aqueous immiscible scintillator containing an extractant for the nuclide of interest (extractive scintillator) is shown to allow better control of alpha peak shift due to quenching, a significant reduction of beta-gamma interference, and, usually, a low background. The desirability of using a multichannel pulse-height analyzer in the above two counting methods is stressed. The use of equipment and procedures designed for alpha liquid scintillation counting is shown to allow alpha spectrometry with an energy resolution capability of 200 to 300 keV full-peak-width-at-half-peak-height and a background of 0.3 to 1.0 counts/min, or as low as 0.01 counts/min if pulse-shape discrimination methods are used. Methods for preparing animal bone and tissue samples for assay are described

  9. Scintillator tiles with SiPM readout for calorimetry and fast timing in SuperKEKB commissioning

    Energy Technology Data Exchange (ETDEWEB)

    Windel, Hendrik [Max-Planck-Institute for Physics (Germany); Collaboration: CALICE-D-Collaboration

    2016-07-01

    The CALICE collaboration is studying plastic scintillators coupled to silicon photomultipliers as sensors for calorimeters for future linear colliders like ILC and CLIC. Current detector concepts foresee up to ten million channels for the hadronic calorimeter. A larger number of different types of SiPMs and scintillator materials exist and their properties have to be investigated to provide best results. For these purposes a dedicated laboratory setup has been developed to provide high resolution scanning of the scintillator tiles with a radioactive source. The data acquisition of this setup as well as a fast online analysis has been implemented in LABVIEW. A modified version of this setup, together with hardware previously used for measuring timing properties of hardronic showers, will be used in the commissioning phase of the SuperKEKB accelerator. This contribution discusses results from detailed investigations of different scintillator tiles, including the study of different materials. Key performance criteria for their application in calorimetry and in background measurements with high time resolution at SuperKEKB are also presented. The CALICE collaboration is studying plastic scintillators coupled to silicon photomultipliers as sensors for calorimeters for future linear colliders like ILC and CLIC. Current detector concepts foresee up two ten million channels for the hadronic calorimeter. In the real detector several thousands of these plastic scintillators will be used. To provide comparability between each of them, investigations of homogeneity for different packaging types and scintillating materials are needed as well as different attempts in tile arrangement to take inter tile crosstalk into account. A larger number of different types of SiPMs and scintillator materials exist and their properties have to be investigated to provide best results. For these purposes a dedicated LABVIEW based setup consistent of data acquisition system (DAQ) and analysis

  10. Comparison of the methods for determination of scintillation light yield

    CERN Document Server

    Sysoeva, E; Zelenskaya, O

    2002-01-01

    One of the most important characteristics of scintillators is the light yield. It depends not only on the properties of scintillators, but also on the conditions of measurements. Even for widely used crystals, such as alkali halide scintillators NaI(Tl) and CsI(Tl), light yield data, obtained by various authors, are different. Therefore, it is very important to choose the convenient method of the light yield measurements. In the present work, methods for the determination of the physical light yield, based on measurements of pulse amplitude, single-electron pulses and intrinsic photomultiplier resolution are discussed. These methods have been used for the measurements of light yield of alkali halide crystals and oxide scintillators. Repeatability and reproducibility of results were determined. All these methods are rather complicated in use, not for measurements, but for further data processing. Besides that, they demand a precise determination of photoreceiver's parameters, as well as determination of light ...

  11. New liquid scintillators for fiber-optic applications

    International Nuclear Information System (INIS)

    Lutz, S.S.; Franks, L.A.; Flournoy, J.M.; Lyons, P.B.

    1981-01-01

    New long-wavelength-emitting, high-speed, liquid scintillators have been developed and tailored specifically for plasma diagnostic experiments employing fiber optics. These scintillators offer significant advantages over commercially available plastic scintillators in terms of sensitivity and bandwidth. FWHM response times as fast as 350 ps have been measured. Emission spectra, time response data, and relative sensitivity information are presented

  12. Photonic crystal scintillators and methods of manufacture

    Science.gov (United States)

    Torres, Ricardo D.; Sexton, Lindsay T.; Fuentes, Roderick E.; Cortes-Concepcion, Jose

    2015-08-11

    Photonic crystal scintillators and their methods of manufacture are provided. Exemplary methods of manufacture include using a highly-ordered porous anodic alumina membrane as a pattern transfer mask for either the etching of underlying material or for the deposition of additional material onto the surface of a scintillator. Exemplary detectors utilizing such photonic crystal scintillators are also provided.

  13. Imaging performance comparison between a LaBr3: Ce scintillator based and a CdTe semiconductor based photon counting compact gamma camera.

    Science.gov (United States)

    Russo, P; Mettivier, G; Pani, R; Pellegrini, R; Cinti, M N; Bennati, P

    2009-04-01

    The authors report on the performance of two small field of view, compact gamma cameras working in single photon counting in planar imaging tests at 122 and 140 keV. The first camera is based on a LaBr3: Ce scintillator continuous crystal (49 x 49 x 5 mm3) assembled with a flat panel multianode photomultiplier tube with parallel readout. The second one belongs to the class of semiconductor hybrid pixel detectors, specifically, a CdTe pixel detector (14 x 14 x 1 mm3) with 256 x 256 square pixels and a pitch of 55 microm, read out by a CMOS single photon counting integrated circuit of the Medipix2 series. The scintillation camera was operated with selectable energy window while the CdTe camera was operated with a single low-energy detection threshold of about 20 keV, i.e., without energy discrimination. The detectors were coupled to pinhole or parallel-hole high-resolution collimators. The evaluation of their overall performance in basic imaging tasks is presented through measurements of their detection efficiency, intrinsic spatial resolution, noise, image SNR, and contrast recovery. The scintillation and CdTe cameras showed, respectively, detection efficiencies at 122 keV of 83% and 45%, intrinsic spatial resolutions of 0.9 mm and 75 microm, and total background noises of 40.5 and 1.6 cps. Imaging tests with high-resolution parallel-hole and pinhole collimators are also reported.

  14. Scintillation camera for high activity sources

    International Nuclear Information System (INIS)

    Arseneau, R.E.

    1976-01-01

    A scintillation camera is provided with electrical components which expand the intrinsic maximum rate of acceptance for processing of pulses emanating from detected radioactive events. Buffer storage is provided to accommodate temporary increases in the level of radioactivity. An early provisional determination of acceptability of pulses allows many unacceptable pulses to be discarded at an early stage

  15. Performance studies towards a TOF-PET sensor using Compton scattering at plastic scintillators

    Science.gov (United States)

    Kuramoto, M.; Nakamori, T.; Gunji, S.; Kamada, K.; Shoji, Y.; Yoshikawa, A.; Aoki, T.

    2018-01-01

    We have developed a sensor head for a time-of-flight (TOF) PET scanner using plastic scintillators that have a very fast timing property. Given the very small cross section of photoelectric absorption in plastic scintillators at 511 keV, we use Compton scattering in order to compensate for detection efficiency. The detector will consist of two layers of scatterers and absorbers which are made of plastic and inorganic scintillators such as GAGG:Ce, respectively. Signals are read by monolithic Multi Pixel Photon Counters, and with energy deposits and interaction time stamps are being acquired. The scintillators are built to be capable of resolving interaction position in three dimensions, so that our system has also a function of depth-of-interaction (DOI) PET scanners. TOF resolution of ~ 200 ps (FWHM) is achieved in both cases of using the leading-edge discriminator and time-walk correction and using a configuration sensitive to DOI. Both the position resolution and spectroscopy are demonstrated using the prototype data acquisition system, with Compton scattering events subsequently being obtained. We also demonstrated that the background rejection technique using the Compton cone constraint could be valid with our system.

  16. Homogeneity of Gd-based garnet transparent ceramic scintillators for gamma spectroscopy

    Science.gov (United States)

    Seeley, Z. M.; Cherepy, N. J.; Payne, S. A.

    2013-09-01

    Transparent polycrystalline ceramic scintillators based on the composition Gd1.49Y1.49Ce0.02Ga2.2Al2.8O12 are being developed for gamma spectroscopy detectors. Scintillator light yield and energy resolution depend on the details of various processing steps, including powder calcination, green body formation, and sintering atmosphere. We have found that gallium sublimation during vacuum sintering creates compositional gradients in the ceramic and can degrade the energy resolution. While sintering in oxygen produces ceramics with uniform composition and little afterglow, light yields are reduced, compared to vacuum sintering. By controlling the atmosphere during the various process steps, we were able to minimize the gallium sublimation, resulting in a more homogeneous composition and improved gamma spectroscopy performance.

  17. Scintillation scanner

    International Nuclear Information System (INIS)

    Mehrbrodt, A.W.; Mog, W.F.; Brunnett, C.J.

    1977-01-01

    A scintillation scanner having a visual image producing means coupled through a lost motion connection to the boom which supports the scintillation detector is described. The lost motion connection is adjustable to compensate for such delays as may occur between sensing and recording scintillations. 13 claims, 5 figures

  18. Highly segmented, high resolution time-of-flight system

    Energy Technology Data Exchange (ETDEWEB)

    Nayak, T.K.; Nagamiya, S.; Vossnack, O.; Wu, Y.D.; Zajc, W.A. [Columbia Univ., New York, NY (United States); Miake, Y.; Ueno, S.; Kitayama, H.; Nagasaka, Y.; Tomizawa, K.; Arai, I.; Yagi, K [Univ. of Tsukuba, (Japan)

    1991-12-31

    The light attenuation and timing characteristics of time-of-flight counters constructed of 3m long scintillating fiber bundles of different shapes and sizes are presented. Fiber bundles made of 5mm diameter fibers showed good timing characteristics and less light attenuation. The results for a 1.5m long scintillator rod are also presented.

  19. Scintillation measurements at Bahir Dar during the high solar activity phase of solar cycle 24

    Energy Technology Data Exchange (ETDEWEB)

    Kriegel, Martin; Jakowski, Norbert; Berdermann, Jens; Sato, Hiroatsu [German Aerospace Center (DLR), Neustrelitz (Germany). Inst. of Communications and Navigation; Mersha, Mogese Wassaie [Bahir Dar Univ. (Ethiopia). Washera Geospace and Radar Science Lab.

    2017-04-01

    Small-scale ionospheric disturbances may cause severe radio scintillations of signals transmitted from global navigation satellite systems (GNSSs). Consequently, smallscale plasma irregularities may heavily degrade the performance of current GNSSs such as GPS, GLONASS or Galileo. This paper presents analysis results obtained primarily from two high-rate GNSS receiver stations designed and operated by the German Aerospace Center (DLR) in cooperation with Bahir Dar University (BDU) at 11.6 N, 37.4 E. Both receivers collect raw data sampled at up to 50 Hz, from which characteristic scintillation parameters such as the S4 index are deduced. This paper gives a first overview of the measurement setup and the observed scintillation events over Bahir Dar in 2015. Both stations are located close to one another and aligned in an east-west, direction which allows us to estimate the zonal drift velocity and spatial dimension of equatorial ionospheric plasma irregularities. Therefore, the lag times of moving electron density irregularities and scintillation patterns are derived by applying cross-correlation analysis to high-rate measurements of the slant total electron content (sTEC) along radio links between a GPS satellite and both receivers and to the associated signal power, respectively. Finally, the drift velocity is derived from the estimated lag time, taking into account the geometric constellation of both receiving antennas and the observed GPS satellites.

  20. Impact of precursor purity on optical properties and radiation detection of CsI:Tl scintillators

    Energy Technology Data Exchange (ETDEWEB)

    Saengkaew, Phannee; Cheewajaroen, Kulthawat; Yenchai, Chadet; Thong-aram, Decho [Chulalongkorn University, Department of Nuclear Engineering, Faculty of Engineering, Bangkok (Thailand); Sanorpim, Sakuntam [Chulalongkorn University, Department of Physics, Faculty of Science, Bangkok (Thailand); Jitpukdee, Manit [Kasetsart University, Department of Applied Radiation and Isotope, Faculty of Science, Bangkok (Thailand); Yordsri, Visittapong; Thanachayanont, Chanchana [Ministry of Science and Technology, National Metal and Materials Technology Center, National Science and Technology Development Agency, Pathumthani (Thailand); Nuntawong, Noppadon [Ministry of Science and Technology, National Electronic and Computer Technology Center, National Science and Technology Development Agency, Pathumthani (Thailand)

    2016-08-15

    Cesium iodide doped with thallium (CsI:Tl) crystals was grown to develop the gamma-ray detectors by using low-cost raw materials. Effect of impurities on optical properties and radiation detection performance was investigated. By a modified homemade Bridgman-Stockbarger technique, CsI:Tl samples were grown in two levels of CsI and TlI reactant materials, i.e., having as a very high purity of 99.999 % and a high purity of 99.9 %. XRD measurements indicate CsI:Tl crystals having a good quality with a dominant (110) plane. Having a cubic structure, a lattice constant of CsI crystals of 0.4574 nm and a crystallite size of 43.539 nm were obtained. From the lower-purity raw materials, calcite was found in an orange crystal with a lattice constant of 0.4560 nm and a crystallite size of 43.089 nm. By PL measurements, the optical properties of the CsI:Tl crystals were analyzed. ∝540-nm-wavelength PL peak was observed from the colorless high-purity crystal, and ∝600-nm-wavelength PL peak was observed from the orange crystal. The brighter PL emission was obtained from the orange crystals suggesting impurities. CsI:Tl surface morphology by SEM exhibited a smooth surface with some parallel crystal facets. For electrical properties of high-quality CsI:Tl crystals, the electrical resistances were 230 ± 16 MΩ in cross-sectional direction and 714 ± 136 MΩ in vertical direction with respect to more homogeneous crystal quality in cross-sectional direction than that in vertical direction. TEM measurement was applied to evaluate the microstructure of colorless CsI:Tl crystal with different patterns of a cubic structure. Both CsI:Tl crystals show good efficiencies and good resolutions. Maintaining the same electronic conditions and amplifications, the colorless CsI:Tl scintillators represented a higher detection efficiency at 122 keV of Co-57 of 78.4 % and the energy resolution of 23.3 % compared to the detection efficiency of 75.9 % and the energy resolution of 34.6 % of the

  1. Calibration of LiBaF sub 3 Ce scintillator for fission spectrum neutrons

    CERN Document Server

    Reeder, P L

    2002-01-01

    The scintillator LiBaF sub 3 doped with small amounts of Ce sup + sup 3 has the ability to distinguish heavy charged particles (p, d, t, or alpha) from beta and/or gamma radiation based on the presence or absence of nanosecond components in the scintillation light output. Since the neutron capture reaction on sup 6 Li produces recoil alphas and tritons, this scintillator also discriminates between neutron induced events and beta or gamma interactions. An experimental technique using a time-tagged sup 2 sup 5 sup 2 Cf source has been used to measure the efficiency of this scintillator for neutron capture, the calibration of neutron capture pulse height, and the pulse height resolution--all as a function of incident neutron energy.

  2. Multi-frequency GNSS robust carrier tracking for ionospheric scintillation mitigation

    Science.gov (United States)

    Vilà-Valls, Jordi; Closas, Pau; Curran, James T.

    2017-10-01

    Ionospheric scintillation is the physical phenomena affecting radio waves propagating from the space through the ionosphere to earth. The signal distortion induced by scintillation can pose a major threat to some GNSS application. Scintillation is one of the more challenging propagation scenarios, particularly affecting high-precision GNSS receivers which require high quality carrier phase measurements; and safety critical applications which have strict accuracy, availability and integrity requirements. Under ionospheric scintillation conditions, GNSS signals are affected by fast amplitude and phase variations, which can compromise the receiver synchronization. To take into account the underlying correlation among different frequency bands, we propose a new multivariate autoregressive model (MAR) for the multi-frequency ionospheric scintillation process. Multi-frequency GNSS observations and the scintillation MAR are modeled in state-space, allowing independent tracking of both line-of-sight phase variations and complex gain scintillation components. The resulting joint synchronization and scintillation mitigation problem is solved using a robust nonlinear Kalman filter, validated using real multi-frequency scintillation data with encouraging results.

  3. A theory of timing in scintillation counters based on maximum likelihood estimation

    International Nuclear Information System (INIS)

    Tomitani, Takehiro

    1982-01-01

    A theory of timing in scintillation counters based on the maximum likelihood estimation is presented. An optimum filter that minimizes the variance of timing is described. A simple formula to estimate the variance of timing is presented as a function of photoelectron number, scintillation decay constant and the single electron transit time spread in the photomultiplier. The present method was compared with the theory by E. Gatti and V. Svelto. The proposed method was applied to two simple models and rough estimations of potential time resolution of several scintillators are given. The proposed method is applicable to the timing in Cerenkov counters and semiconductor detectors as well. (author)

  4. Interstellar Scintillation and Scattering of Micro-arc-second AGN

    Directory of Open Access Journals (Sweden)

    David L. Jauncey

    2016-11-01

    Full Text Available The discovery of the first quasar 3C 273 led directly to the discovery of their variability at optical and radio wavelengths. We review the radio variability observations, in particular the variability found at frequencies below 1 GHz, as well as those exhibiting intra-day variability (IDV at cm wavelengths. Observations have shown that IDV arises principally from scintillation caused by scattering in the ionized interstellar medium of our Galaxy. The sensitivity of interstellar scintillation towards source angular sizes has provided a powerful tool for studying the most compact components of radio-loud AGN at microarcsecond and milliarcsecond scale resolution.

  5. Radiation Damage in Scintillating Crystals

    CERN Document Server

    Zhu Ren Yuan

    1998-01-01

    Crystal Calorimetry in future high energy physics experiments faces a new challenge to maintain its precision in a hostile radiation environment. This paper discusses the effects of radiation damage in scintillating crystals, and concludes that the predominant radiation damage effect in crystal scintillators is the radiation induced absorption, or color center formation, not the loss of the scintillation light yield. The importance of maintaining crystal's light response uniformity and the feasibility to build a precision crystal calorimeter under radiation are elaborated. The mechanism of the radiation damage in scintillating crystals is also discussed. While the damage in alkali halides is found to be caused by the oxygen or hydroxyl contamination, it is the structure defects, such as oxygen vacancies, cause damage in oxides. Material analysis methods used to reach these conclusions are presented in details.

  6. Scintillator detector array

    International Nuclear Information System (INIS)

    Cusano, D.A.; Dibianca, F.A.

    1981-01-01

    This patent application relates to a scintillator detector array for use in computerized tomography and comprises a housing including a plurality of chambers, the said housing having a front wall transmissive to x-rays and side walls opaque to x-rays, such as of tungsten and tantalum, a liquid scintillation medium including a soluble fluor, the solvent for the fluor being disposed in the chambers. The solvent comprises either an intrinsically high Z solvent or a solvent which has dissolved therein a high Z compound e.g. iodo or bromonaphthalene; or toluene, xylene or trimethylbenzene with a lead or tin alkyl dissolved therein. Also disposed about the chambers are a plurality of photoelectric devices. (author)

  7. Liquid scintillation solution

    International Nuclear Information System (INIS)

    Long, E.C.

    1977-01-01

    A liquid scintillation solution is described which includes (1) a scintillation solvent (toluene and xylene), (2) a primary scintillation solute (PPO and Butyl PBD), (3) a secondary scintillation solute (POPOP and Dimethyl POPOP), (4) a plurality of substantially different surfactants and (5) a filter dissolving and/or transparentizing agent. 8 claims

  8. Lower bounds on scintillation detector timing performance

    International Nuclear Information System (INIS)

    Clinthorne, N.H.; Rogers, W.L.; Hero, A.O. III.; Petrick, N.A.

    1990-01-01

    Fundamental method-independent limits on the timing performance of scintillation detectors are useful for identifying regimes in which either present timing methods are nearly optimal or where a considerable performance gain might be realized using better pulse processing techniques. Several types of lower bounds on mean-squared timing error (MSE) performance have been developed and applied to scintillation detectors. The simple Cramer-Rao (CR) bound can be useful in determining the limiting MSE for scintillators having a relatively high rate of photon problction such as BaF 2 and NaI(Tl); however, it tends to overestimate the achievalbe performance for scintillators with lower rates such as BGO. For this reason, alternative bounds have been developed using rate-distortion theory or by assuming that the conversion of energy to scintillation light must pass through excited states which have exponential lifetime densities. The bounds are functions of the mean scintillation pulse shape, the scintillation intensity, and photodetector characteristics; they are simple to evaluate and can be used to conveniently assess the limiting timing performance of scintillation detectors. (orig.)

  9. Scintillation counter and wire chamber front end modules for high energy physics experiments

    International Nuclear Information System (INIS)

    Baldin, Boris; DalMonte, Lou

    2011-01-01

    This document describes two front-end modules developed for the proposed MIPP upgrade (P-960) experiment at Fermilab. The scintillation counter module was developed for the Plastic Ball detector time and charge measurements. The module has eight LEMO 00 input connectors terminated with 50 ohms and accepts negative photomultiplier signals in the range 0.25...1000 pC with the maximum input voltage of 4.0 V. Each input has a passive splitter with integration and differentiation times of ∼20 ns. The integrated portion of the signal is digitized at 26.55 MHz by Analog Devices AD9229 12-bit pipelined 4-channel ADC. The differentiated signal is discriminated for time measurement and sent to one of the four TMC304 inputs. The 4-channel TMC304 chip allows high precision time measurement of rising and falling edges with ∼100 ps resolution and has internal digital pipeline. The ADC data is also pipelined which allows deadtime-less operation with trigger decision times of ∼4 (micro)s. The wire chamber module was developed for MIPP EMCal detector charge measurements. The 32-channel digitizer accepts differential analog signals from four 8-channel integrating wire amplifiers. The connection between wire amplifier and digitizer is provided via 26-wire twist-n-flat cable. The wire amplifier integrates input wire current and has sensitivity of 275 mV/pC and the noise level of ∼0.013 pC. The digitizer uses the same 12-bit AD9229 ADC chip as the scintillator counter module. The wire amplifier has a built-in test pulser with a mask register to provide testing of the individual channels. Both modules are implemented as a 6Ux220 mm VME size board with 48-pin power connector. A custom europack (VME) 21-slot crate is developed for housing these front-end modules.

  10. Experimental tests of the new plastic scintillator with pulse shape discrimination capabilities EJ-299-33

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-01-21

    We have studied the prototype of a new plastic scintillator material (EJ-299-33) engineered for gamma-neutron discrimination. Energy and time resolutions as well as pulse shape discrimination capability have been compared with those of standard plastic and liquid scintillators. EJ-299-33 characteristics are somewhat poorer compared to standard scintillators. However, results obtained with the new plastic material suggest its possible use in basic research (time-of-flight measurements) as well as in Homeland Security applications (neutron/gamma monitoring device)

  11. A spectrometer filter for semiconductor and scintillation detectors

    International Nuclear Information System (INIS)

    Andronov, O.I.; Brovchenko, V.G.; Evdokimov, S.T.

    1995-01-01

    The paper describes an integrating low-pass filter which takes signals from a delay line. The filter changes triangular pulses into rectangular ones. The energy resolution of a semiconductor detector whose signal is processed by the filter is 15-20% better than using a common RC-filter. The integrator stores a charge due to the scintillation pulse during the integration time without loss. The energy and time resolution of the device with the spectrometer filter is better than with an RC-filter. The energy resolution of a bismuth-germanate detector in recording radiation from 137 Cs is 9.75%

  12. Scintillation camera

    International Nuclear Information System (INIS)

    Zioni, J.; Klein, Y.; Inbar, D.

    1975-01-01

    The scintillation camera is to make pictures of the density distribution of radiation fields created by the injection or administration radioactive medicaments into the body of the patient. It contains a scintillation crystal, several photomultipliers and computer circuits to obtain an analytical function at the exits of the photomultiplier which is dependent on the position of the scintillations at the time in the crystal. The scintillation crystal is flat and spatially corresponds to the production site of radiation. The photomultipliers form a pattern whose basic form consists of at least three photomultipliers. They are assigned to at least two crossing parallel series groups where a vertical running reference axis in the crystal plane belongs to each series group. The computer circuits are each assigned to a reference axis. Each series of a series group assigned to one of the reference axes in the computer circuit has an adder to produce a scintillation dependent series signal. Furthermore, the projection of the scintillation on this reference axis is calculated. A series signal is used for this which originates from a series chosen from two neighbouring photomultiplier series of this group. The scintillation must have appeared between these chosen series. They are termed as basic series. The photomultiplier can be arranged hexagonally or rectangularly. (GG/LH) [de

  13. Characterizing a pulse-resolved dosimetry system for complex radiotherapy beams using organic scintillators

    DEFF Research Database (Denmark)

    Beierholm, Anders Ravnsborg; Ottosson, Rickard; Lindvold, Lars René

    2011-01-01

    A fast-readout dosimetry system based on fibre-coupled organic scintillators has been developed for the purpose of conducting point measurements of absorbed dose in radiotherapy beams involving high spatial and temporal dose gradients. The system measures the dose for each linac radiation pulse w...... and quality assurance of complex radiotherapy treatments.......A fast-readout dosimetry system based on fibre-coupled organic scintillators has been developed for the purpose of conducting point measurements of absorbed dose in radiotherapy beams involving high spatial and temporal dose gradients. The system measures the dose for each linac radiation pulse....... No significant differences between measurements and simulations were observed. The temporal resolution of the system was demonstrated by measuring dose per pulse, beam start-up transients and the quality factor for 6 MV. The precision of dose per pulse measurements was within 2.7% (1 SD) for a 10 cm × 10 cm...

  14. Investigation of the imaging properties of inorganic scintillation screens using high energetic ion beams

    Energy Technology Data Exchange (ETDEWEB)

    Lieberwirth, Alice [TU Darmstadt (Germany); JWG Universitaet Frankfurt/Main (Germany); Forck, Peter; Sieber, Thomas [GSI Darmstadt (Germany); Ensinger, Wolfgang; Lederer, Stephan [TU Darmstadt (Germany); Kester, Oliver [JWG Universitaet Frankfurt/Main (Germany)

    2016-07-01

    Inorganic scintillation screens are a common diagnostics tool in heavy ion accelerators. In order to investigate the imaging properties of various screen materials, four different material compositions were irradiated at GSI, using protons up to Uranium ions as projectiles. Beams were extracted from SIS18 with high energy (300 MeV/u) in slow and fast extraction mode. During irradiation the scintillation response of the screens was simultaneously recorded by two different optical setups to investigate light output, profile characteristics and emission spectra. It was observed, that fast extracted beams induce in general lower light output than slow extracted beams, while the light output per deposited energy decreases with atomic number. The analysis of the spectral emission as well as investigations with classical optical methods showed no significant defect-building in all materials, not even under irradiation with increasing beam intensity or over long time periods. The investigated scintillation screens can be considered as stable under irradiation with high energetic heavy ion pulses and are appropriate for beam diagnostics applications in future accelerator facilities like FAIR. Characteristic properties and application areas of the screens are presented in the poster.

  15. Reconstruction of scintillations coordinates in cylindrical large detector with radial arrangement of photomultipliers

    CERN Document Server

    Alekseev, V M; Verbitskij, V S; Verbitskij, S S; Lapik, M A; Tselebrovskij, A N; Lapik, A M; Rusakov, A V; Savopulo, M L; Smirnov, V V; Chubarov, M N

    2002-01-01

    Paper describes algorithm to calculate scintillation coordinates elaborated for a coordinate-sensitive large detector based on liquid scintillator with radial arrangement of nine FEU-174 photomultipliers. Paper contains the simulation results of coordinate resolution dependence in detector centre on energy of gamma-quanta within 0.2-8 MeV range. Using this algorithm one processed the experimental data obtained with application of sup 6 sup 0 Co gamma-radiation source and the results of determination of scintillation coordinates for gamma-quanta beam. The accuracy of coordinate determination in detector centre when applying the descried algorithm constitutes approx 10 mm

  16. Investigations of X-ray response of single wire anode Ar-N2 flow type gas scintillation proportional counters

    International Nuclear Information System (INIS)

    Garg, S.P.; Sharma, R.C.

    1984-01-01

    The X-ray response of single wire anode gas scintillation proportional counters of two different geometries operated with argon+nitrogen gases in continuous flow has been investigated with wire anodes of diameters 25 μm to 1.7 mm. An energy resolution of 19% is obtained for 5.9 keV X-rays entering the counter perpendicular to the anode in pill-box geometry with 25 μm diameter anode. With cylindrical geometry counters energy obtained at 5.9 keV are 18%, 24% and 33% for 50 μm, 0.5 mm and 1.7 mm diameter anodes respectively. An analysis of the observed resolution shows that the contribution from photon counting statistics to the relative variance of scintillation pulses even for X-rays in Ar-N 2 single wire anode gas scintillation proportional counters is small and is not a limiting factor. The energy resolution with thicker anodes, where the contribution from the variance of the charge multiplication factor also has been minimised, is found to deteriorate mainly by the interaction in the scintillation production region. Comments are made on the possibility of improvement in energy resolution by suppression of pulses due to such interactions with the help of the pulse risetime discrimination technique. (orig.)

  17. Time of gamma radiation transport in NaI(Tl) scintillators

    International Nuclear Information System (INIS)

    Matarrita, A.S.

    1976-01-01

    The distribution of time intervals in function of the energy, ocurred between the incidence of a gamma radiation in the face of a scintillation crystal and the arrival of the correspondent scintillation at photocathode, is calculated. The mean square fluctuation these time interval, relating to resolution of the detector system is determined. The calculations are done for NaI (Tl) cylindrical crystals with the radiation source placed in the symmetry axis, in two situations: para axial incidence and oblique incidence, indicating a good agreement with experimental data. (M.C.K.) [pt

  18. Waveshifters and Scintillators for Ionizing Radiation Detection

    International Nuclear Information System (INIS)

    Baumgaugh, B.; Bishop, J.; Karmgard, D.; Marchant, J.; McKenna, M.; Ruchti, R.; Vigneault, M.; Hernandez, L.; Hurlbut, C.

    2007-01-01

    Scintillation and waveshifter materials have been developed for the detection of ionizing radiation in an STTR program between Ludlum Measurements, Inc. and the University of Notre Dame. Several new waveshifter materials have been developed which are comparable in efficiency and faster in fluorescence decay than the standard material Y11 (K27) used in particle physics for several decades. Additionally, new scintillation materials useful for fiber tracking have been developed which have been compared to 3HF. Lastly, work was done on developing liquid scintillators and paint-on scintillators and waveshifters for high radiation environments

  19. Scintillation response of Y.sub.3./sub.Al.sub.5./sub.O.sub.12./sub.:Pr.sup.3+./sup. single crystal scintillators

    Czech Academy of Sciences Publication Activity Database

    Sreebunpeng, K.; Chewpraditkul, W.; Babin, Vladimir; Nikl, Martin; Nejezchleb, K.

    2013-01-01

    Roč. 56, Sept (2013), s. 94-97 ISSN 1350-4487 R&D Projects: GA ČR GAP204/12/0805 Institutional support: RVO:68378271 Keywords : energy resolution * light yield * photofraction * scintillation detectors * YAG:Pr Subject RIV: BH - Optics, Masers, Lasers Impact factor: 1.140, year: 2013

  20. Predicting the timing properties of phosphor-coated scintillators using Monte Carlo light transport simulation

    International Nuclear Information System (INIS)

    Roncali, Emilie; Schmall, Jeffrey P; Viswanath, Varsha; Berg, Eric; Cherry, Simon R

    2014-01-01

    Current developments in positron emission tomography focus on improving timing performance for scanners with time-of-flight (TOF) capability, and incorporating depth-of-interaction (DOI) information. Recent studies have shown that incorporating DOI correction in TOF detectors can improve timing resolution, and that DOI also becomes more important in long axial field-of-view scanners. We have previously reported the development of DOI-encoding detectors using phosphor-coated scintillation crystals; here we study the timing properties of those crystals to assess the feasibility of providing some level of DOI information without significantly degrading the timing performance. We used Monte Carlo simulations to provide a detailed understanding of light transport in phosphor-coated crystals which cannot be fully characterized experimentally. Our simulations used a custom reflectance model based on 3D crystal surface measurements. Lutetium oxyorthosilicate crystals were simulated with a phosphor coating in contact with the scintillator surfaces and an external diffuse reflector (teflon). Light output, energy resolution, and pulse shape showed excellent agreement with experimental data obtained on 3 × 3 × 10 mm 3  crystals coupled to a photomultiplier tube. Scintillator intrinsic timing resolution was simulated with head-on and side-on configurations, confirming the trends observed experimentally. These results indicate that the model may be used to predict timing properties in phosphor-coated crystals and guide the coating for optimal DOI resolution/timing performance trade-off for a given crystal geometry. Simulation data suggested that a time stamp generated from early photoelectrons minimizes degradation of the timing resolution, thus making this method potentially more useful for TOF-DOI detectors than our initial experiments suggested. Finally, this approach could easily be extended to the study of timing properties in other scintillation crystals, with a

  1. Ultrafast Readout of Scintillating Fibres Using Upgraded Position-Sensitive Photomultipliers

    CERN Multimedia

    2002-01-01

    % RD-17 \\\\ \\\\To design a high rate topological trigger device for the future DIRAC Experiment at CERN an extensive work is in progress on a scintillating-fibre detector using a position-sensitive photomultiplier. Several detector prototypes with different lengths ($<$~50~cm) of sensitive area have been tested at T7S~PS beam. \\\\ \\\\With 0.5~mm diameter fibres a spatial resolution of $\\sim$125~$\\mu$m was obtained with a detection efficiency higher than 95\\%. The time resolution is $\\sim$600~ps, and the track position is properly digitized in real time (about 10~ns) by multi-channel peak sensing circuit. Based on experimental data simulations were also performed a comparison of different types of front-end electronics for multi-channel readout.

  2. A high resolution, low power time-of-flight system for the space experiment AMS

    International Nuclear Information System (INIS)

    Alvisi, D.; Anselmo, F.; Baldini, L.; Bari, G.; Basile, M.; Bellagamba, L.; Bruni, A.; Bruni, G.; Boscherini, D.; Casadei, D.; Cara Romeo, G.; Castellini, G.; Cifarelli, L.; Cindolo, F.; Contin, A.; De Pasquale, S.; Giusti, P.; Iacobucci, G.; Laurenti, G.; Levi, G.; Margotti, A.; Massam, T.; Nania, R.; Palmonari, F.; Polini, A.; Recupero, S.; Sartorelli, G.; Williams, C.; Zichichi, A.

    1999-01-01

    The system of plastic scintillator counters for the AMS experiment is described. The main characteristics of the detector are: (a) large sensitive area (four 1.6 m 2 planes) with small dead space; (b) low-power consumption (150 W for the power and the read-out electronics of 336 PMs); (c) 120 ps time resolution

  3. SU-D-BRC-07: System Design for a 3D Volumetric Scintillation Detector Using SCMOS Cameras

    Energy Technology Data Exchange (ETDEWEB)

    Darne, C; Robertson, D; Alsanea, F; Beddar, S [UT MD Anderson Cancer Center, Houston, TX (United States)

    2016-06-15

    Purpose: The purpose of this project is to build a volumetric scintillation detector for quantitative imaging of 3D dose distributions of proton beams accurately in near real-time. Methods: The liquid scintillator (LS) detector consists of a transparent acrylic tank (20×20×20 cm{sup 3}) filled with a liquid scintillator that when irradiated with protons generates scintillation light. To track rapid spatial and dose variations in spot scanning proton beams we used three scientific-complementary metal-oxide semiconductor (sCMOS) imagers (2560×2160 pixels). The cameras collect optical signal from three orthogonal projections. To reduce system footprint two mirrors oriented at 45° to the tank surfaces redirect scintillation light to cameras for capturing top and right views. Selection of fixed focal length objective lenses for these cameras was based on their ability to provide large depth of field (DoF) and required field of view (FoV). Multiple cross-hairs imprinted on the tank surfaces allow for image corrections arising from camera perspective and refraction. Results: We determined that by setting sCMOS to 16-bit dynamic range, truncating its FoV (1100×1100 pixels) to image the entire volume of the LS detector, and using 5.6 msec integration time imaging rate can be ramped up to 88 frames per second (fps). 20 mm focal length lens provides a 20 cm imaging DoF and 0.24 mm/pixel resolution. Master-slave camera configuration enable the slaves to initiate image acquisition instantly (within 2 µsec) after receiving a trigger signal. A computer with 128 GB RAM was used for spooling images from the cameras and can sustain a maximum recording time of 2 min per camera at 75 fps. Conclusion: The three sCMOS cameras are capable of high speed imaging. They can therefore be used for quick, high-resolution, and precise mapping of dose distributions from scanned spot proton beams in three dimensions.

  4. SU-D-BRC-07: System Design for a 3D Volumetric Scintillation Detector Using SCMOS Cameras

    International Nuclear Information System (INIS)

    Darne, C; Robertson, D; Alsanea, F; Beddar, S

    2016-01-01

    Purpose: The purpose of this project is to build a volumetric scintillation detector for quantitative imaging of 3D dose distributions of proton beams accurately in near real-time. Methods: The liquid scintillator (LS) detector consists of a transparent acrylic tank (20×20×20 cm"3) filled with a liquid scintillator that when irradiated with protons generates scintillation light. To track rapid spatial and dose variations in spot scanning proton beams we used three scientific-complementary metal-oxide semiconductor (sCMOS) imagers (2560×2160 pixels). The cameras collect optical signal from three orthogonal projections. To reduce system footprint two mirrors oriented at 45° to the tank surfaces redirect scintillation light to cameras for capturing top and right views. Selection of fixed focal length objective lenses for these cameras was based on their ability to provide large depth of field (DoF) and required field of view (FoV). Multiple cross-hairs imprinted on the tank surfaces allow for image corrections arising from camera perspective and refraction. Results: We determined that by setting sCMOS to 16-bit dynamic range, truncating its FoV (1100×1100 pixels) to image the entire volume of the LS detector, and using 5.6 msec integration time imaging rate can be ramped up to 88 frames per second (fps). 20 mm focal length lens provides a 20 cm imaging DoF and 0.24 mm/pixel resolution. Master-slave camera configuration enable the slaves to initiate image acquisition instantly (within 2 µsec) after receiving a trigger signal. A computer with 128 GB RAM was used for spooling images from the cameras and can sustain a maximum recording time of 2 min per camera at 75 fps. Conclusion: The three sCMOS cameras are capable of high speed imaging. They can therefore be used for quick, high-resolution, and precise mapping of dose distributions from scanned spot proton beams in three dimensions.

  5. Luminescence rise time in self-activated PbWO{sub 4} and Ce-doped Gd{sub 3}Al{sub 2}Ga{sub 3}O{sub 12} scintillation crystals

    Energy Technology Data Exchange (ETDEWEB)

    Auffray, E. [CERN, Geneva (Switzerland); Augulis, R. [Center for Physical Sciences and Technology, Savanorių av. 231, Vilnius (Lithuania); Borisevich, A. [Research Institute for Nuclear Problems, Bobruiskaya str. 11, Minsk (Belarus); Gulbinas, V. [Center for Physical Sciences and Technology, Savanorių av. 231, Vilnius (Lithuania); Fedorov, A.; Korjik, M. [Research Institute for Nuclear Problems, Bobruiskaya str. 11, Minsk (Belarus); Lucchini, M.T. [CERN, Geneva (Switzerland); Mechinsky, V. [Research Institute for Nuclear Problems, Bobruiskaya str. 11, Minsk (Belarus); Nargelas, S. [Vilnius University, Universiteto str. 3, Vilnius (Lithuania); Songaila, E. [Center for Physical Sciences and Technology, Savanorių av. 231, Vilnius (Lithuania); Tamulaitis, G. [Vilnius University, Universiteto str. 3, Vilnius (Lithuania); Vaitkevičius, A., E-mail: augustas.vaitkevicius@ff.vu.lt [Vilnius University, Universiteto str. 3, Vilnius (Lithuania); Zazubovich, S. [Institute of Physics, University of Tartu, W. Ostwaldi Str. 1, Tartu (Estonia)

    2016-10-15

    The time resolution of scintillation detectors of ionizing radiation is one of the key parameters sought for in the current and future high-energy physics experiments. This study is encouraged by the necessity to find novel detection methods enabling a sub-10-ps time resolution in scintillation detectors and is focused on the exploitation of fast luminescence rise front. Time-resolved photoluminescence (PL) spectroscopy and thermally stimulated luminescence techniques have been used to study two promising scintillators: self-activated lead tungstate (PWO, PbWO{sub 4}) and Ce-doped gadolinium aluminum gallium garnet (GAGG, Gd{sub 3}Al{sub 2}Ga{sub 3}O{sub 12}). A sub-picosecond PL rise time is observed in PWO, while longer processes in the PL response in GAGG:Ce are detected and studied. The mechanisms responsible for the PL rise time in self-activated and doped scintillators are under discussion. - Highlights: • Photoluminescence rise time is studied in two scintillators: PWO and GAGG:Ce. • Sub-picosecond photoluminescence rise time in PWO is observed for the first time. • A multicomponent luminescence rise edge is observed in GAGG:Ce. • The mechanisms behind luminescence kinetics in the crystals are under discussion.

  6. Radiation damage studies on new liquid scintillators and liquid-core scintillating fibers

    International Nuclear Information System (INIS)

    Golovkin, S.V.

    1994-01-01

    The radiation resistant of some new liquid scintillation and capillaries filled with liquid scintillators has been presented. It was found that scintillation efficiency of the scintillator based on 1-methyl naphthalene with a new R39 only by 10% at the dose of 190 Mrad and the radiation resistance of thin liquid-core scintillating was decreased fibers exceeded 60 Mrad. 35 refs

  7. Scintillator performance at low dose rates and low temperatures for the CMS High Granularity Calorimeter for HL-LHC

    CERN Document Server

    Ricci-Tam, Francesca

    2018-01-01

    The High Luminosity LHC (HL-LHC) will integrate 10 times more luminosity than the LHC, posing significant challenges for radiation tolerance, especially for forward calorimetry, and highlights the issue for future colliders. As part of its HL-LHC upgrade program, the CMS collaboration is designing a High Granularity Calorimeter to replace the existing endcap calorimeters. The upgrade includes both electromagnetic and hadronic components, with the latter using a mixture of silicon sensors (in the highest radiation regions at high pseudorapidity) and scintillator as its active components. The scintillator will nevertheless receive large doses accumulated at low dose rates, and will have to operate at low temperature - around -30 degrees Celsius. We discuss measurements of scintillator radiation tolerance, from in-situ measurements from the current CMS endcap calorimeters, and from measurements at low temperature and low dose-rate at gamma sources in the laboratory.

  8. Geophysical analysis of coherent satellite scintillation data

    Science.gov (United States)

    Fremouw, E. J.; Lansinger, J. M.; Miller, D. A.

    1981-11-01

    In May of 1976, Air Force Satellite P76-5 was launched with the Defense Nuclear Agency's Wideband beacon, DNA-002, as its sole payload. Several researchers have employed the resulting data in studies of ionospheric structure and its effect on transionospheric radio communications. In the present work, recordings of amplitude and phase scintillation imposed on Wideband's VHF and UHF signals by the ionosphere have been used to study medium-scale structures in the auroral-zone F layer. Results include quantitative identification of a very close relationship between scintillation and solar/geomagnetic activity, together with lack of a seasonal variation in scintillation activity in the Alaskan sector. A surprisingly high correlation (90%) was found between monthly means of phase-scintillation index, on the one hand, and sunspot number and 10-cm solar radio flux, on the other. The high-latitude scintillation boundary was found to be very similar to the soft-electron precipitation boundary, including similarity in expansion rates with increasing magnetic activity. Interestingly, it is systematically shifted poleward of the precipitation boundary on the day side of the earth and equatorward on the night side. Taken together, the results of this research disclose a rather direct relationship between scintillation and soft-electron precipitation, with plasma convection likely playing an important role in generation of the scintillation-producing irregularities.

  9. Cerium doped lanthanum halides: fast scintillators for medical imaging; Halogenures de lanthane dopes cerium des scintillateurs rapides pour l'imagerie medicale

    Energy Technology Data Exchange (ETDEWEB)

    Selles, O

    2006-12-15

    This work is dedicated to two recently discovered scintillating crystals: cerium doped lanthanum halides (LaCl{sub 3}:Ce{sup 3+} and LaBr{sub 3}:Ce{sup 3+}).These scintillators exhibit interesting properties for gamma detection, more particularly in the field of medical imaging: a short decay time, a high light yield and an excellent energy resolution. The strong hygroscopicity of these materials requires adapting the usual experimental methods for determining physico-chemical properties. Once determined, these can be used for the development of the industrial manufacturing process of the crystals. A proper comprehension of the scintillation mechanism and of the effect of defects within the material lead to new possible ways for optimizing the scintillator performance. Therefore, different techniques are used (EPR, radioluminescence, laser excitation, thermally stimulated luminescence). Alongside Ce{sup 3+} ions, self-trapped excitons are involved in the scintillation mechanism. Their nature and their role are detailed. The knowledge of the different processes involved in the scintillation mechanism leads to the prediction of the effect of temperature and doping level on the performance of the scintillator. A mechanism is proposed to explain the thermally stimulated luminescence processes that cause slow components in the light emission and a loss of light yield. Eventually the study of afterglow reveals a charge transfer to deep traps involved in the high temperature thermally stimulated luminescence. (author)

  10. Neutron detection in a high gamma-ray background with EJ-301 and EJ-309 liquid scintillators

    International Nuclear Information System (INIS)

    Stevanato, L.; Cester, D.; Nebbia, G.; Viesti, G.

    2012-01-01

    Using a fast digitizer, the neutron–gamma discrimination capability of the new liquid scintillator EJ-309 is compared with that obtained using standard EJ-301. Moreover the capability of both the scintillation detectors to identify a weak neutron source in a high gamma-ray background is demonstrated. The probability of neutron detection is PD=95% at 95% confidence level for a gamma-ray background corresponding to a dose rate of 100 μSv/h.

  11. Scintillating Optical Fiber Imagers for biology

    International Nuclear Information System (INIS)

    Mastrippolito, R.

    1990-01-01

    S.O.F.I (Scintillating Optical Fiber Imager) is a detector developed to replace the autoradiographic films used in molecular biology for the location of radiolabelled ( 32 P) DNA molecules in blotting experiments. It analyses samples on a 25 x 25 cm 2 square area still 25 times faster than autoradiographic films, with a 1.75 and 3 mm resolution for two orthogonal directions. This device performs numerised images with a dynamic upper than 100 which allows the direct quantitation of the analysed samples. First, this thesis describes the S.O.F.I. development (Scintillating Optical Fibers, coding of these fibers and specific electronic for the treatment of the Multi-Anode Photo-Multiplier signals) and experiments made in collaboration with molecular biology laboratories. In a second place, we prove the feasibility of an automatic DNA sequencer issued from S.O.F.I [fr

  12. Solid state scintillators for gamma spectrometry

    International Nuclear Information System (INIS)

    La Mela, G.; Torrisi, M.

    1991-01-01

    Using different scintillator crystals, measurements of energy resolution and detection efficiency have been performed to detect gamma rays of energy ranging between 500 en 1550 KeV. This investigation is devoted to characterize the best systems to detect photons coming from positron annihilation processes, such as a PET apparatus where the medical image is the final aim of the investigation, and gamma emission from radioisotopes of biomedical interest

  13. Trigger and electronics issues for scintillating fiber tracking

    International Nuclear Information System (INIS)

    Baumbaugh, A.E.

    1994-01-01

    Scintillating Fiber technology has made great advances and has demonstrated great promise for high speed charged particle tracking and triggering. The small detector sizes and fast scintillation floors available, make them very promising for use at high luminosity experiments at today's and tomorrow's colliding and fixed target experiments where high rate capability is essential. This paper will discuss some of the system aspects which should be considered by anyone attempting to design a scintillating fiber tracking system and high speed tracking trigger. As the reader will see, seemingly simple decisions can have far reaching effects on overall system performance

  14. A helical scintillating fiber hodoscope

    CERN Document Server

    Altmeier, M; Bisplinghoff, J; Bissel, T; Bollmann, R; Busch, M; Büsser, K; Colberg, T; Demiroers, L; Diehl, O; Dohrmann, F; Engelhardt, H P; Eversheim, P D; Felden, O; Gebel, R; Glende, M; Greiff, J; Gross, A; Gross-Hardt, R; Hinterberger, F; Jahn, R; Jeske, M; Jonas, E; Krause, H; Lahr, U; Langkau, R; Lindemann, T; Lindlein, J; Maier, R; Maschuw, R; Mayer-Kuckuck, T; Meinerzhagen, A; Naehle, O; Pfuff, M; Prasuhn, D; Rohdjess, H; Rosendaal, D; Von Rossen, P; Sanz, B; Schirm, N; Schulz-Rojahn, M; Schwarz, V; Scobel, W; Thomas, S; Trelle, H J; Weise, E; Wellinghausen, A; Wiedmann, W; Woller, K; Ziegler, R

    1999-01-01

    A novel scintillating fiber hodoscope in helically cylindric geometry has been developed for detection of low multiplicity events of fast protons and other light charged particles in the internal target experiment EDDA at the Cooler Synchrotron COSY. The hodoscope consists of 640 scintillating fibers (2.5 mm diameter), arranged in four layers surrounding the COSY beam pipe. The fibers are helically wound in opposing directions and read out individually using 16-channel photomultipliers connected to a modified commercial encoding system. The detector covers an angular range of 9 deg. <= THETA<=72 deg. and 0 deg. <=phi (cursive,open) Greek<=360 deg. in the lab frame. The detector length is 590 mm, the inner diameter 161 mm. Geometry and granularity of the hodoscope afford a position resolution of about 1.3 mm. The detector design took into consideration a maximum of reliability and a minimum of maintenance. An LED array may be used for monitoring purposes. (author)

  15. Multi-frequency GNSS robust carrier tracking for ionospheric scintillation mitigation

    Directory of Open Access Journals (Sweden)

    Vilà-Valls Jordi

    2017-01-01

    Full Text Available Ionospheric scintillation is the physical phenomena affecting radio waves propagating from the space through the ionosphere to earth. The signal distortion induced by scintillation can pose a major threat to some GNSS application. Scintillation is one of the more challenging propagation scenarios, particularly affecting high-precision GNSS receivers which require high quality carrier phase measurements; and safety critical applications which have strict accuracy, availability and integrity requirements. Under ionospheric scintillation conditions, GNSS signals are affected by fast amplitude and phase variations, which can compromise the receiver synchronization. To take into account the underlying correlation among different frequency bands, we propose a new multivariate autoregressive model (MAR for the multi-frequency ionospheric scintillation process. Multi-frequency GNSS observations and the scintillation MAR are modeled in state-space, allowing independent tracking of both line-of-sight phase variations and complex gain scintillation components. The resulting joint synchronization and scintillation mitigation problem is solved using a robust nonlinear Kalman filter, validated using real multi-frequency scintillation data with encouraging results.

  16. Scintillation properties of pure and Ca-doped ZnWO4 crystals

    International Nuclear Information System (INIS)

    Danevich, F.A.; Shkulkova, O.G.; Henry, S.; Kraus, H.; McGowan, R.; Mikhailik, V.B.; Telfer, J.

    2008-01-01

    Following the investigations of the structure and scintillation properties of Ca-doped zinc tungstate powder [phys. stat. sol. (a) 204, 730 (2007)] a single-crystal of ZnWO 4 -Ca (0.5 mol%) was grown and characterised. The relative light output, energy resolution and decay characteristics were measured for pure and Ca-doped ZnWO 4 scintillators. An increase in the light yield of ∝40% compared with the undoped crystal, and an energy resolution 9.6% ( 137 Cs) were obtained for Ca-doped ZnWO 4 . The observed improvement is attributed to the reduction of self-absorption (bleaching) of the crystal. The cause of bleaching as well as the possible contribution of scattering is discussed. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  17. Pinhole SPECT: high resolution imaging of brain tumours in small laboratory animals

    International Nuclear Information System (INIS)

    Franceschim, M.; Bokulic, T.; Kusic, Z.; Strand, S.E.; Erlandsson, K.

    1994-01-01

    The performance properties of pinhole SPECT and the application of this technology to evaluate radionuclide uptake in brain in small laboratory animals were investigated. System sensitivity and spatial resolution measurements of a rotating scintillation camera system were made for a low energy pinhole collimator equipped with 2.0 mm aperture pinhole insert. Projection data were acquired at 4 degree increments over 360 degrees in the step and shoot mode using a 4.5 cm radius of rotation. Pinhole planar and SPECT imaging were obtained to evaluate regional uptake of Tl-201, Tc-99m-MIBI, Tc-99m-HMPAO and Tc-99m-DTPA in tumor and control regions of the brain in a primary brain tumor model in Fisher 344 rats. Pinhole SPECT images were reconstructed using a modified cone- beam algorithm developed from a two dimensional fan-beam filtered backprojection algorithm. The reconstructed transaxial resolution of 2.8 FWHM and system sensitivity of 0.086 c/s/kBq with the 2.0 mm pinhole collimator aperture were measured. Tumor to non-tumor uptake ratios at 19-28 days post tumor cell inoculation varied by a factor > 20:1 on SPECT images. Pinhole SPECT provides an important new approach for performing high resolution imaging: the resolution properties of pinhole SPECT are superior to those which have been achieved with conventional SPECT or PET imaging technologies. (author)

  18. A new PET detector concept for compact preclinical high-resolution hybrid MR-PET

    Science.gov (United States)

    Berneking, Arne; Gola, Alberto; Ferri, Alessandro; Finster, Felix; Rucatti, Daniele; Paternoster, Giovanni; Jon Shah, N.; Piemonte, Claudio; Lerche, Christoph

    2018-04-01

    This work presents a new PET detector concept for compact preclinical hybrid MR-PET. The detector concept is based on Linearly-Graded SiPM produced with current FBK RGB-HD technology. One 7.75 mm x 7.75 mm large sensor chip is coupled with optical grease to a black coated 8 mm x 8 mm large and 3 mm thick monolithic LYSO crystal. The readout is obtained from four readout channels with the linear encoding based on integrated resistors and the Center of Gravity approach. To characterize the new detector concept, the spatial and energy resolutions were measured. Therefore, the measurement setup was prepared to radiate a collimated beam to 25 different points perpendicular to the monolithic scintillator crystal. Starting in the center point of the crystal at 0 mm / 0 mm and sampling a grid with a pitch of 1.75 mm, all significant points of the detector were covered by the collimator beam. The measured intrinsic spatial resolution (FWHM) was 0.74 +/- 0.01 mm in x- and 0.69 +/- 0.01 mm in the y-direction at the center of the detector. At the same point, the measured energy resolution (FWHM) was 13.01 +/- 0.05 %. The mean intrinsic spatial resolution (FWHM) over the whole detector was 0.80 +/- 0.28 mm in x- and 0.72 +/- 0.19 mm in y-direction. The energy resolution (FWHM) of the detector was between 13 and 17.3 % with an average energy resolution of 15.7 +/- 1.0 %. Due to the reduced thickness, the sensitivity of this gamma detector is low but still higher than pixelated designs with the same thickness due to the monolithic crystals. Combining compact design, high spatial resolution, and high sensitivity, the detector concept is particularly suitable for applications where the scanner bore size is limited and high resolution is required - as is the case in small animal hybrid MR-PET.

  19. Scintillation properties of Ca co-doped L(Y)SO:Ce between 193 K and 373 K for TOF-PET/MRI

    International Nuclear Information System (INIS)

    Weele, David N ter; Schaart, Dennis R; Dorenbos, Pieter

    2014-01-01

    Time-of-flight Positron Emission Tomography (TOF-PET) and TOF-PET/MRI require scintillators with high light yield, short decay time, and short rise time in order to obtain high timing resolution. LSO:Ce and LYSO:Ce are commonly used. Ca co-doped LSO:Ce shows improved scintillation properties. The decay time constant of LSO:Ce,0.2%Ca (~33 ns) is shorter than standard LSO:Ce (~38-40 ns), and it has about 15% higher light yield. We measured scintillation pulse shapes and photoelectron yields of LSO:Ce, LSO:Ce,0.2%Ca, LYSO:Ce, LYSO:Ce,20ppmCa, LYSO:0.11%Ce,0.2%Mg, and LYSO:0.2%Ce,0.2%Ca at temperatures ranging from 193 K to 373 K. To study rise times we built a set-up in which samples are excited by 100 ps (FWHM) x-ray pulses.

  20. Investigation of organic liquid-scintillator optical properties

    Energy Technology Data Exchange (ETDEWEB)

    Winter, Juergen; Feilitzsch, Franz von; Goeger-Neff, Marianne; Lewke, Timo; Meindl, Quirin; Oberauer, Lothar; Potzel, Walter; Todor, Sebastian; Wurm, Michael [Physik Department E15, Technische Universitaet Muenchen, James-Franck-Str., 85748 Garching (Germany); Marrodan Undagoitia, Teresa [Physik Department E15, Technische Universitaet Muenchen, James-Franck-Str., 85748 Garching (Germany); Physik-Institut, Universitaet Zuerich (Switzerland)

    2009-07-01

    The characterization of different organic liquid-scintillator mixtures is an important step towards the design of a large-scale detector such as LENA (Low Energy Neutrino Astronomy). Its physics goals, extending from particle and geological to astrophysical issues, set high demands on the optical properties of the liquid scintillator. Therefore, small-scale experiments are carried out in order to optimize the final scintillator mixture. PXE, LAB, and dodecane are under consideration as solvents. Setups for the determination of scintillator properties are presented, such as attenuation length, light yield, emission spectra, fluorescence decay times, and quenching factors. Furthermore, results are discussed.

  1. Performance study of Philips digital silicon photomultiplier coupled to scintillating crystals

    International Nuclear Information System (INIS)

    Liu, Z.; Pizzichemi, M.; Paganoni, M.; Auffray, E.; Lecoq, P.

    2016-01-01

    Silicon photomultipliers (SiPMs) and scintillators are often arranged in the shape of arrays in Positron Emission Tomography (PET) systems. Digital SiPMs provide signal readout in single photon avalanche diode (SPAD) level. From the photon count rate measurement of each SPAD cell of digital SiPM, we found that the output scintillating photons distribute in an area larger than the scintillator physical coupling area. Taking advantage of the possibility to enable/disable individual cells of the digital SiPM, a group of Lutetium-yttrium oxyorthosilicate (LYSO) crystals with different dimensions coupled to a digital SiPM was used to study the influence of using different SiPM active area on the number of photons detected, energy resolution and coincidence time resolution (CTR). For the same crystal coupled to the digital SiPM, the larger the active area of digital SiPM, the higher the number of photons detected. The larger active area of the digital SiPM also results in a better energy resolution after saturation correction. The best energy resolution full width half maximum (FWHM) obtained for the 2×2×5mm 3 , 2×2×10 mm 3 , 2×2×15mm 3 , 2×2×20mm 3 LYSO crystals was 10.7%, 11.6%, 12.1%, 12.5%, respectively. For crystals with different cross sections coupled to the digital SiPM, we found that the larger the cross section of coupling area, the more photons were detected and thus a better energy resolution was obtained. The CTR of crystals fully wrapped with Teflon or without wrapping was measured by positioning two identical crystals facing each other. A larger area of digital SiPM improves the CTR and the CTR reaches the plateau when the active area is larger than 2.2×2.2mm 2 with both two configurations of wrapping. The best CTR value for the 2×2×5mm 3 , 2×2×10mm 3 , 2×2×15mm 3 , 2×2×20mm 3 LYSO crystals was 128.9 ps, 148.4 ps, 171.6 ps, 177.9 ps, respectively. The measurements performed lead us to conclude that optimising the coupling between crystal

  2. Research in high energy physics: Scintillating fiber detector development for the SSC: Annual progress report

    International Nuclear Information System (INIS)

    Ruchti, R.C.

    1988-01-01

    The scintillating fiber detector development program at the University of Notre Dame is divided into several components. These include: Research on scintillating glass fiber materials; Research on scintillating plastic fiber materials; Research on scintillating liquids in fiber capillaries; Studies of improvements in image intensification and light amplification of appropriate test and development facilities at Notre Dame. The overall goal of the program is to develop efficient scintillating fiber detectors with long, optical attenuation length, and excellent radiation resistance properties for tracking and microvertex detectors and as component active sampling materials for scintillation calorimetry. We now discuss each of these programs in turn. 2 figs., 3 tabs

  3. Scintillation characteristics of phosphich-detector for detection of beta- and gamma-radiations

    CERN Document Server

    Ananenko, A A; Gavrilyuk, V

    2002-01-01

    The results of the study on the influence of individual peculiarities of the compound scintillation detector structure on the value and stability of the light yield by the gamma- and beta-radiation combined registration are presented. The phosphich detector is manufactured from the sodium iodide monocrystal, activated by thallium, and the scintillation plastic on the polystyrol basis. The comparison of the experimental results with the mathematical modeling data revealed certain regularities of the process of forming the phosphich detector light signal. The recommendations are worked out by means whereof the following characteristics of the scintillation unit: the light yield and its stability, amplitude resolution and the peak-to-valley ratio by the gamma- and beta-radiation registration were improved

  4. Radiation Hard and High Light Yield Scintillator Search for CMS Phase II Upgrade

    CERN Document Server

    Tiras, Emrah

    2015-01-01

    The CMS detector at the LHC requires a major upgrade to cope with the higher instantaneous luminosity and the elevated radiation levels. The active media of the forward backing hadron calorimeters is projected to be radiation-hard, high light yield scintillation materials or similar alternatives. In this context, we have studied various radiation-hard scintillating materials such as Polyethylene Terephthalate (PET), Polyethylene Naphthalate (PEN), High Efficiency Mirror (HEM) and quartz plates with various coatings. The quartz plates are pure Cerenkov radiators and their radiation hardness has been confirmed. In order to increase the light output, we considered organic and inorganic coating materials such as p-Terphenyl (pTp), Anthracene and Gallium-doped Zinc Oxide (ZnO Ga) that are applied as thin layers on the surface of the quartz plates. Here, we present the results of the related test beam activities, laboratory measurements and recent developments.

  5. Characterization of a ZnSe scintillating bolometer prototype for neutrinoless double beta decay search

    Directory of Open Access Journals (Sweden)

    Tenconi M.

    2014-01-01

    Full Text Available As proposed in the LUCIFER project, ZnSe crystals are attractive materials to realize scintillating bolometers aiming at the search for neutrinoless double beta decay of the promising isotope 82Se. However, the optimization of the ZnSe-based detectors is rather complex and requires a wide-range investigation of the crystal features: optical properties, crystalline quality, scintillation yields and bolometric behaviour. Samples tested up to now show problems in the reproducibility of crucial aspects of the detector performance. In this work, we present the results obtained with a scintillating bolometer operated aboveground at about 25 mK. The detector energy absorber was a single 1 cm3 ZnSe crystal. The good energy resolution of the heat channel (about 14 keV at 1460 keV and the excellent alpha/beta discrimination capability are very encouraging for a successful realization of the LUCIFER program. The bolometric measurements were completed by optical tests on the crystal (optical transmission and luminescence measurements down to 10 K and investigation of the crystalline structure. The work here described provides a set of parameters and procedures useful for a complete pre-characterization of ZnSe crystals in view of the realization of highly performing scintillating bolometers.

  6. Results from a new combined test of an electromagnetic liquid argon calorimeter with a hadronic scintillating-tile calorimeter

    Czech Academy of Sciences Publication Activity Database

    Akhmadaliev, S.; Albiol, F.; Amaral, P.; Lokajíček, Miloš; Němeček, Stanislav

    2000-01-01

    Roč. 449, - (2000), s. 461-477 ISSN 0168-9002 R&D Projects: GA MPO RP-4210/69 Institutional research plan: CEZ:AV0Z1010920 Keywords : liquid argon * calorimeter * hadronic scintillating- tile * CERN SPS * ATLAS * LHC * energy resolution * pions Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 0.964, year: 2000

  7. Novel, full 3D scintillation dosimetry using a static plenoptic camera

    Science.gov (United States)

    Goulet, Mathieu; Rilling, Madison; Gingras, Luc; Beddar, Sam; Beaulieu, Luc; Archambault, Louis

    2014-01-01

    Purpose: Patient-specific quality assurance (QA) of dynamic radiotherapy delivery would gain from being performed using a 3D dosimeter. However, 3D dosimeters, such as gels, have many disadvantages limiting to quality assurance, such as tedious read-out procedures and poor reproducibility. The purpose of this work is to develop and validate a novel type of high resolution 3D dosimeter based on the real-time light acquisition of a plastic scintillator volume using a plenoptic camera. This dosimeter would allow for the QA of dynamic radiation therapy techniques such as intensity-modulated radiation therapy (IMRT) or volumetric-modulated arc therapy (VMAT). Methods: A Raytrix R5 plenoptic camera was used to image a 10 × 10 × 10 cm3 EJ-260 plastic scintillator embedded inside an acrylic phantom at a rate of one acquisition per second. The scintillator volume was irradiated with both an IMRT and VMAT treatment plan on a Clinac iX linear accelerator. The 3D light distribution emitted by the scintillator volume was reconstructed at a 2 mm resolution in all dimensions by back-projecting the light collected by each pixel of the light-field camera using an iterative reconstruction algorithm. The latter was constrained by a beam's eye view projection of the incident dose acquired using the portal imager integrated with the linac and by physical consideration of the dose behavior as a function of depth in the phantom. Results: The absolute dose difference between the reconstructed 3D dose and the expected dose calculated using the treatment planning software Pinnacle3 was on average below 1.5% of the maximum dose for both integrated IMRT and VMAT deliveries, and below 3% for each individual IMRT incidences. Dose agreement between the reconstructed 3D dose and a radiochromic film acquisition in the same experimental phantom was on average within 2.1% and 1.2% of the maximum recorded dose for the IMRT and VMAT delivery, respectively. Conclusions: Using plenoptic camera

  8. High-pressure 3He-Xe gas scintillators for simultaneous detection of neutrons and gamma rays over a large energy range

    International Nuclear Information System (INIS)

    Tornow, W.; Esterline, J.H.; Leckey, C.A.; Weisel, G.J.

    2011-01-01

    We report on features of high-pressure 3 He-Xe gas scintillators which have not been sufficiently addressed in the past. Such gas scintillators can be used not only for the efficient detection of low-energy neutrons but at the same time for the detection and identification of γ-rays as well. Furthermore, 3 He-Xe gas scintillators are also very convenient detectors for fast neutrons in the 1-10 MeV energy range and for high-energy γ-rays in the 7-15 MeV energy range. Due to their linear pulse-height response and self calibration via the 3 He(n,p) 3 H reaction, neutron and γ-ray energies can easily be determined in this high-energy regime.

  9. The scintillating optical fiber isotope experiment: Bevalac calibrations of test models

    International Nuclear Information System (INIS)

    Connell, J.J.; Binns, W.R.; Dowkontt, P.F.; Epstein, J.W.; Israel, M.H.; Klarmann, J.; Washington Univ., St. Louis, MO; Webber, W.R.; Kish, J.C.

    1990-01-01

    The Scintillating Optical Fiber Isotope Experiment (SOFIE) is a Cherenkov dE/dx-range experiment being developed to study the isotopic composition of cosmic rays in the iron region with sufficient resolution to resolve isotopes separated by one mass unit at iron. This instrument images stopping particles with a block of scintillating optical fibers coupled to an image intensified video camera. From the digitized video data the trajectory and range of particles stopping in the fiber bundle can be determined; this information, together with a Cherenkov measurement, is used to determine mass. To facilitate this determination, a new Cherenkov response equation was derived for heavy ions at energies near threshold in thick Cherenkov radiators. Test models of SOFIE were calibrated at the Lawrence Berkeley Laboratory's Bevalac heavy ion accelerator in 1985 and 1986 using beams of iron nuclei with energies of 465 to 515 MeV/nucleon. This paper presents the results of these calibrations and discusses the design of the SOFIE Bevalac test models in the context of the scientific objectives of the eventual balloon experiment. The test models show a mass resolution of σ A ≅0.30 amu and a range resolution of σ R ≅250 μm. These results are sufficient for a successful cosmic ray isotope experiment, thus demonstrating the feasibility of the detector system. The SOFIE test models represent the first successful application in the field of cosmic ray astrophysics of the emerging technology of scintillating optical fibers. (orig.)

  10. Solid scintillator 'Ready Cap' for measurement with a liquid scintillation counter

    International Nuclear Information System (INIS)

    Ijiri, Kenichi; Endo, Masashi; Nogawa, Norio; Tsuda, Shoko; Nakamura, Aiko; Morikawa, Naotake; Osaki, Susumu.

    1990-01-01

    'Ready Cap', a small plastic container coated with solid scintillator has recently been introduced (Beckman Instruments, Inc.). Pulse height spectra and counting efficiencies obtained with a liquid scintillator and Ready Cap using a liquid scintillation counter were compared for 15 different radionuclides. For radionuclides emitting low-energy β-rays or characteristic X-rays, the spectra for Ready Cap shifted toward the higher energy side compared with the spectra for the liquid scintillator. This tendency was reversed for the nuclides emitting higher-energy β-radiations ( 36 Cl and 32 P). Generally, counting efficiencies both in Ready Cap and in liquid scintillator increased with increase in the energy of β- or X-rays. For some nuclides, Ready Cap gave higher counting efficiencies and for others it gave lower values than in the liquid scintillator. However, the differences were not large within each nuclide. The use of Ready Cap is recommended for measurements of radionuclides when liquid scintillation cocktails have no means of waste disposal under the present Japanese radioisotope regulation. (author)

  11. LET dependence of scintillation yields in liquid argon

    Energy Technology Data Exchange (ETDEWEB)

    Doke, Tadayoshi; Hitachi, Akira; Kikuchi, Jun; Crawford, H J; Lindstrom, P J; Masuda, Kimiaki; Shibamura, Eido; Takahashi, Tan

    1988-06-01

    Scintillation yields (scintillation intensity per unit absorbed energy) in liquid argon for ionizing particles are reviewed as a function of LET for the particles. The maximum scintillation yield, which is obtained for relativistic heavy ions from Ne to La, is about 1.2 times larger than that for gamma rays in NaI(Tl) crystal. In the low LET region, the scintillation yields for relativistic electrons, protons and He ions are 10-20% lower than the maximum yield. This tendency can be explained by taking into account the existence of the electrons which have escaped from their parent ions. In the high LET region, a quenching effect due to high ionization density is observed for alpha particles, fission fragments and relativistic Au ions.

  12. Ultrafast readout of scintillating fibers using upgraded position-sensitive photomultipliers

    International Nuclear Information System (INIS)

    Onel, Y.

    1994-01-01

    Experimental results obtained with commercially available position-sensitive photomultipliers (PSPM) coupled with 0.5 mm diameter scintillating fiber arrays show some promising performances such as space resolution better than 200 μm and time resolution ∼ 1.5 ns with a detection efficiency higher than 90%. Major progress has also been recently achieved with an upgrade of a PSPM based on new grid dynode structures. Two-track spatial resolution has been studied using the upgraded PSPM. Initial studies demonstrate that two tracks separated by a minimum distance of 3 mm are resolved

  13. Energy resolution measurements of LaBr3:Ce scintillating crystals with an ultra-high quantum efficiency photomultiplier tube

    International Nuclear Information System (INIS)

    Pani, R.; Cinti, M.N.; Scafe, R.; Pellegrini, R.; Vittorini, F.; Bennati, P.; Ridolfi, S.; Lo Meo, S.; Mattioli, M.; Baldazzi, G.; Pisacane, F.; Navarria, F.; Moschini, G.; Boccaccio, P.; Orsolini Cencelli, V.; Sacco, D.

    2009-01-01

    The performance of the new prototype of high quantum efficiency PMT (43% at 380 nm), Hamamatsu R7600U-200, was studied coupled to a LaBr 3 :Ce crystal with the size of o12.5 mmx12.5 mm. The energy resolution results were compared with ones from two PMTs, Hamamatsu R7600U and R6231MOD, with 22% and 30% quantum efficiency (QE), respectively. Moreover, the photodetectors were equipped with tapered and un-tapered voltage dividers to study the non-linearity effects on pulse height distribution, due to very high peak currents induced in the PMT by the fast and intense light pulse of LaBr 3 :Ce. The results show an energy resolution improvement with UBA PMT of about 20%, in the energy range of 80-662 keV, with respect to the BA one.

  14. Perspectives on the future development of new scintillators

    International Nuclear Information System (INIS)

    Melcher, C.L.

    2005-01-01

    The search for new scintillators has become increasingly sophisticated and increasingly successful in recent years, driven to a large degree by the rapidly growing needs of medical imaging and high energy physics. Better understanding of the various scintillation mechanisms has led to innovative new materials for both gamma-ray and neutron detection, and the concept of scintillator design and engineering has emerged, whereby materials are optimized according to the scintillation properties needed by specific applications. Numerous promising candidates have been identified during the last few years, and several are currently being actively developed for commercial production. Economical crystal growth often represents a significant challenge in the practical application of new scintillation materials

  15. High-resolution X-ray television and high-resolution video recorders

    International Nuclear Information System (INIS)

    Haendle, J.; Horbaschek, H.; Alexandrescu, M.

    1977-01-01

    The improved transmission properties of the high-resolution X-ray television chain described here make it possible to transmit more information per television image. The resolution in the fluoroscopic image, which is visually determined, depends on the dose rate and the inertia of the television pick-up tube. This connection is discussed. In the last few years, video recorders have been increasingly used in X-ray diagnostics. The video recorder is a further quality-limiting element in X-ray television. The development of function patterns of high-resolution magnetic video recorders shows that this quality drop may be largely overcome. The influence of electrical band width and number of lines on the resolution in the X-ray television image stored is explained in more detail. (orig.) [de

  16. BC404 scintillators as gamma locators studied via Geant4 simulations

    Science.gov (United States)

    Cortés, M. L.; Hoischen, R.; Eisenhauer, K.; Gerl, J.; Pietralla, N.

    2014-05-01

    In many applications in industry and academia, an accurate determination of the direction from where gamma rays are emitted is either needed or desirable. Ion-beam therapy treatments, the search for orphan sources, and homeland security applications are examples of fields that can benefit from directional sensitivity to gamma-radiation. Scintillation detectors are a good option for these types of applications as they have relatively low cost, are easy to handle and can be produced in a large range of different sizes. In this work a Geant4 simulation was developed to study the directional sensitivity of different BC404 scintillator geometries and arrangements. The simulation includes all the physical processes relevant for gamma detection in a scintillator. In particular, the creation and propagation of optical photons inside the scintillator was included. A simplified photomultiplier tube model was also simulated. The physical principle exploited is the angular dependence of the shape of the energy spectrum obtained from thin scintillator layers when irradiated from different angles. After an experimental confirmation of the working principle of the device and a check of the simulation, the possibilities and limitations of directional sensitivity to gamma radiation using scintillator layers was tested. For this purpose, point-like sources of typical energies expected in ion-beam therapy were used. Optimal scintillator thicknesses for different energies were determined and the setup efficiencies calculated. The use of arrays of scintillators to reconstruct the direction of incoming gamma rays was also studied. For this case, a spherical source emitting Bremsstrahlung radiation was used together with a setup consisting of scintillator layers. The capability of this setup to identify the center of the extended source was studied together with its angular resolution.

  17. Artificial neural networks application for analysis of gamma ray spectrum obtained from the scintillation detectors

    International Nuclear Information System (INIS)

    Stegowski, Z.

    2002-01-01

    Scintillation detectors are commonly used for the gamma ray detection. Actually the small peak resolution and the significant Compton effect fraction limit their utilization in the gamma ray spectrometry analysis. This article presents the artificial neural networks (ANN) application to the analysis of the gamma ray spectra acquired from scintillation detectors. The obtained results validate the effectiveness of the ANN method to spectrometry analysis. (author)

  18. Evaluating scintillator performance in time-resolved hard X-ray studies at synchrotron light sources

    International Nuclear Information System (INIS)

    Rutherford, Michael E.; Chapman, David J.; White, Thomas G.; Drakopoulos, Michael; Rack, Alexander; Eakins, Daniel E.

    2016-01-01

    Scintillator performance in time-resolved, hard, indirect detection X-ray studies on the sub-microsecond timescale at synchrotron light sources is reviewed, modelled and examined experimentally. LYSO:Ce is found to be the only commercially available crystal suitable for these experiments. The short pulse duration, small effective source size and high flux of synchrotron radiation is ideally suited for probing a wide range of transient deformation processes in materials under extreme conditions. In this paper, the challenges of high-resolution time-resolved indirect X-ray detection are reviewed in the context of dynamic synchrotron experiments. In particular, the discussion is targeted at two-dimensional integrating detector methods, such as those focused on dynamic radiography and diffraction experiments. The response of a scintillator to periodic synchrotron X-ray excitation is modelled and validated against experimental data collected at the Diamond Light Source (DLS) and European Synchrotron Radiation Facility (ESRF). An upper bound on the dynamic range accessible in a time-resolved experiment for a given bunch separation is calculated for a range of scintillators. New bunch structures are suggested for DLS and ESRF using the highest-performing commercially available crystal LYSO:Ce, allowing time-resolved experiments with an interframe time of 189 ns and a maximum dynamic range of 98 (6.6 bits)

  19. Evaluating scintillator performance in time-resolved hard X-ray studies at synchrotron light sources

    Energy Technology Data Exchange (ETDEWEB)

    Rutherford, Michael E.; Chapman, David J.; White, Thomas G. [Imperial College London, London (United Kingdom); Drakopoulos, Michael [Diamond Light Source, I12 Joint Engineering, Environmental, Processing (JEEP) Beamline, Didcot, Oxfordshire (United Kingdom); Rack, Alexander [European Synchrotron Radiation Facility, Grenoble (France); Eakins, Daniel E., E-mail: d.eakins@imperial.ac.uk [Imperial College London, London (United Kingdom)

    2016-03-24

    Scintillator performance in time-resolved, hard, indirect detection X-ray studies on the sub-microsecond timescale at synchrotron light sources is reviewed, modelled and examined experimentally. LYSO:Ce is found to be the only commercially available crystal suitable for these experiments. The short pulse duration, small effective source size and high flux of synchrotron radiation is ideally suited for probing a wide range of transient deformation processes in materials under extreme conditions. In this paper, the challenges of high-resolution time-resolved indirect X-ray detection are reviewed in the context of dynamic synchrotron experiments. In particular, the discussion is targeted at two-dimensional integrating detector methods, such as those focused on dynamic radiography and diffraction experiments. The response of a scintillator to periodic synchrotron X-ray excitation is modelled and validated against experimental data collected at the Diamond Light Source (DLS) and European Synchrotron Radiation Facility (ESRF). An upper bound on the dynamic range accessible in a time-resolved experiment for a given bunch separation is calculated for a range of scintillators. New bunch structures are suggested for DLS and ESRF using the highest-performing commercially available crystal LYSO:Ce, allowing time-resolved experiments with an interframe time of 189 ns and a maximum dynamic range of 98 (6.6 bits)

  20. Simulation the spatial resolution of an X-ray imager based on zinc oxide nanowires in anodic aluminium oxide membrane by using MCNP and OPTICS Codes

    Science.gov (United States)

    Samarin, S. N.; Saramad, S.

    2018-05-01

    The spatial resolution of a detector is a very important parameter for x-ray imaging. A bulk scintillation detector because of spreading of light inside the scintillator does't have a good spatial resolution. The nanowire scintillators because of their wave guiding behavior can prevent the spreading of light and can improve the spatial resolution of traditional scintillation detectors. The zinc oxide (ZnO) scintillator nanowire, with its simple construction by electrochemical deposition in regular hexagonal structure of Aluminum oxide membrane has many advantages. The three dimensional absorption of X-ray energy in ZnO scintillator is simulated by a Monte Carlo transport code (MCNP). The transport, attenuation and scattering of the generated photons are simulated by a general-purpose scintillator light response simulation code (OPTICS). The results are compared with a previous publication which used a simulation code of the passage of particles through matter (Geant4). The results verify that this scintillator nanowire structure has a spatial resolution less than one micrometer.