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Digital light processing three-dimensional (3D) printing technique is a powerful tool to rapidly manufacture plastic scintillators of almost any shape or geometric features. In our previous study, the main properties of light output and transmission were analyzed. However, a more detailed study of the other properties is required to develop 3D printed plastic scintillators with expectable and reproducible properties. The 3D printed plastic scintillator displayed an average decay time constants of 15.6 ns, intrinsic energy resolution of 13.2%, and intrinsic detection efficiency of 6.81% for 477 keV Compton electrons from the 137Cs γ-ray source. The 3D printed plastic scintillator showed a similar decay time and intrinsic detection efficiency as that of a commercial plastic scintillator BC408. Furthermore, the presented estimates for the properties showed good agreement with the analyzed data.

International audience; We developed a high spatial resolution and sensitive detector particularly suitable for radiation dose measurements in radiotherapy at small fields and X-ray imaging applications. The detector is based on a silica optical fiber whose sensitive terminal is functionalized by grafting Ag-doped ZnS scintillating materials that emit blue luminescence under X-ray irradiation. Due to the small scintillating head of the detector, the acquisition signal is quite low, and it is measured by a sensitive photon counter plugged at the other terminal of the fiber. The weaker signal can be enhanced significantly by adding a metal coating over the scintillator. Therefore, this study presents the effect of metal thickness and density on the signal amplification at high irradiation energies of 6 MeV and 15 MeV using a Linear Accelerator (LINAC). In addition, the stem effect was characterized for regular to small field beam size and shows that the detector is almost free from stem contribution during high energy irradiation.

Scintillators that convert ionization radiation photons to UV-visible photons have attracted extraordinary attention. Traditional scintillators are associated with a vacuum photomultiplier tube that faces strict constraints of fragility, magnetic fields, and operated voltage, or coupled to a silicon photomultiplier (SiPM) with optical silicone grease. Here, we report a high-performance radiation detector with an indirect photon-to-photon conversion radiation detection model based on perovskite single crystals (SCs), where perovskite SCs have been directly integrated into the window of SiPM by using the solution growth method at low temperature. Tunable X (γ)-ray excited light emission in the range of 414 to 600 nm is obtained with different concentrations of Br doping, which greatly matches the response wavelength of SiPM. Small Br-doped CH

CdTe and CdZnTe crystals are employed for several applications such as IR imaging, X- and gamma ray detection, optical devices, and photovoltaics. These applications require that crystals show peculiar properties. On the other hand, phase diagrams suggest possible growth technologies. In this chapter, the most important synthesis and growth technologies for CdTe and CdZnTe crystals are described together with the post-growth treatments that were adopted for improving material properties. Finally, state of the art of CdTe and CdZnTe crystals are reviewed, problems still open are evidenced and, thus, few indications about possible future developments are summarized.

A simple scintillator kit developed by Ian Bearden [1] was used to prepare a learning experience on gamma ray detection for secondary students. The goal is to offer an opportunity to collect gamma spectra, analyse data and understand how coincidence measurements are useful in space physics and in many other applications.

A quaternary iodide KCa0.8Sr0.2I3:Eu2+ scintillator with 2.5% energy resolution at 662 keV in a 5 mm3 sample shows great potential for use in gamma-ray spectroscopy applications. In this work, we report the state-of-the-art growth of high quality 25, 38, and 50 mm diameter KCa0.8Sr0.2I3:Eu2+ single crystals by the vertical self-seeding Bridgman method. KCa0.8Sr0.2I3:Eu2+ with a size of ∅25 mm × 25 mm can achieve excellent energy resolutions of 3.15% at 662 keV and 6.8% at 122 keV irradiation, which are superior to that of a commercial NaI:Tl+ of the same size. The nonuniformity of light collection and production in ∅25 mm × 25 mm and ∅38 mm × 38 mm KCa0.8Sr0.2I3:Eu2+ crystals was evaluated by using a technique based on a collimated 137Cs source and coupling the crystal to a photomultiplier tube (PMT) in different directions. The performances of the packaged crystals for practical use were also measured.

Quality and performance of a detection system are the crucial parameters in all nuclear physics experiments. This system serves as a source of all signals and noises to be processed. Better performance, higher amplification and lower noises occurrence simplify subsequent signal analysis. In the field of Mossbauer spectroscopy, the spectrum quality and Mossbauer effect are crucial parameters which are affected especially by the quality of the detection system. These parameters were evaluated for different types of a detection setup. Finally an improvement of the spectrum quality by 15% and Mossbauer effect by 7% has been achieved for the natural iron reference absorber measurement in comparison with previous version of the detection system. K e y w o r d s: gamma ray detection, signal processing, Mossbauer spectroscopy, Mossbauer spectrum

In this paper, we propose the fast and efficient detection method using the continuous measurement technique for the gamma-ray signal acquisition. This method is improved than the conventional method for the getting information of the radiation distribution. First, we implement the stereo radiation detection system using gamma-ray sensors and the motion controller. We apply continuous measurement technique to the gamma-ray detector and conduct gamma-ray irradiation test for the comparison of detection techniques. The results show that the continuous measurement technique has the high efficient performance than the conventional method.Key Words : Fast gamma detector, Scintillation detector, Gamma-ray detection, Gamma Imager†Corresponding Author : Dept. of Nuclear convergence Techcnology Development, Korea Atomic Energy Research Institute, Korea.E-mail: yghwang@kaeri.re.kr*Dept. of Nuclear convergence Techcnology Development, Korea Atomic Energy Research Institute, Korea.Received : July 31, 2014; Accepted : August 26, 2014

We have developed a gamma-ray detector based on a single-crystal diamond in order to improve the heat and radiation resistances of gamma-ray monitors. We fabricated prototypes with two types of diamond grown by a chemical vapor deposition method. The count rates with temperature and accumulated dose were obtained using a 137Cs gamma-ray source, then the errors at full scale (%FS) were evaluated using a method to reduce the dark count. The prototype-A worked to 643 K within 2.9%FS and to 3.1 MGy within 4.9%FS; on the other hand, the prototype-B worked to 545 K within 3.4%FS and to 5.0 MGy within 0.47%FS. This study demonstrates that the diamond semiconductor was promising for monitoring with enhanced heat and radiation resistances.

Characterization of the electrical response of HPGe segmented detectors as a function of the interaction position is one of the current goals for the Nuclear Physics community in order to perform γ-ray tracking or even imaging with these detectors. For this purpose, scanning devices must be developed to achieve the signal-position association with the highest precision. With this aim, SALSA, a γ-camera-based scanning system, is under development at our laboratory. In this work, the optimization study aimed to obtain the best spatial resolution in the position-sensitive detectors employed as γ camera is described.

The first Polaris system was built in September 2010 and has gone through significant testing at multiple DOD and DOE facilities as well as at the University of Michigan. It has been biased almost continuously for the 18 months of its current lifespan without any replacement of its detectors. The second Polaris system was built in June 2011 and has also been almost continuously biased during its lifespan. The continuous operation of both devices has provided the best opportunity to study the long-term stability of pixelated CdZnTe detectors. Spectroscopic performance has been monitored throughout each system's lifespan to study their performance over time and the impact on long term operation of these devices. It is shown that the charge transport properties and spectroscopic performance of these CdZnTe detectors are stable over time and devoid of fabrication or assembly issues. It is expected that future detectors will exhibit excellent stability.

LiCaAlF6 scintillators are one of the attractive scintillators for neutron detection. To reduce the effect on gamma-rays, the Ce doped LiCaAlF6 scintillators can discriminate the neutron and gamma-ray events based on the pulse shape discrimination technique. To apply the scintillators for the oil logging, the high temperature characteristics must be investigated. In this paper, the temperature dependence of the neutron-gamma discrimination based on pulse shape discrimination technique in the Ce:LiCaAlF6 scintillator is investigated as one of the high temperature characteristics. The property of pulse shape discrimination in the Ce:LiCaAlF6 has small temperature dependence ranging from 25°C to 150°C. We concluded that the Ce:LiCaAlF6 scintillators can discriminate neutron and gamma-ray events under high temperature condition up to 150°C .

This work reports on the characterization of TlBr detectors for use in nuclear medicine. Several different detectors have been used to assess the potential performance of the material. A 12 mm thick detector with a Frisch collar has been used to achieve an energy resolution of 3.5% at 511 keV and 2.3% at 662 keV. A 0.4 mm thick detector biased at 200 V has been operated in coincidence with an LSO crystal coupled to a PMT and a timing resolution of 24 ns FWHM has been obtained by gating the energy of the events. A strip TlBr detector with 0.4 mm width strips and 0.1 mm inter-strip separation has been used to measure the intrinsic spatial resolution to the level of 1 mm (a result limited by the setup geometry). The results show promising results of TlBr detectors for nuclear medicine applications.

We describe a setup we developed for the measurement of scintillation properties of crystals, from room temperature down to 3 K, under α and γ particle irradiation which resolves lines from both types of excitations. This setup is described here and we report some results obtained with this setup on BGO (Bi4Ge3O12) and ZnWO4 crystals.

Silicon photomultipliers (SiPMs) are expected to replace photomultiplier tubes (PMTs) in several applications that require scintillation detectors with excellent timing resolution, such as time-of-flight positron emission tomography (TOF-PET). However, the theory about the timing resolution of SiPM-based detectors is not yet fully understood. Here we propose a comprehensive statistical model to predict the timing resolution of SiPM-based scintillation detectors. It incorporates the relevant SiPM-related parameters (viz. the single cell electronic response, the single cell gain, the charge carrier transit time spread, and crosstalk) as well as the scintillation pulse rise and decay times, light yield, and energy resolution. It is shown that the proposed model reduces to the well-established Hyman model for timing with PMTs if the number of primary triggers (photoelectrons in case of a PMT) is Poisson distributed and crosstalk and electronic noise are negligible. The model predictions are validated by measurements of the coincidence resolving times (CRT) for 511 keV photons of two identical detectors as a function of SiPM bias voltage, for two different kinds of scintillators, namely LYSO:Ce and LaBr3:5%Ce. CRTs as low as 138 ps +/- 2 ps FWHM for LYSO:Ce and 95 ps +/- 3 ps FWHM for LaBr3:5%Ce were obtained, demonstrating the outstanding timing potential of SiPM-based scintillation detectors. These values were found to be in good agreement with the predicted CRTs of 140 ps FWHM and 95 ps FWHM, respectively. Utilizing the proposed model, it can be shown that the CRTs obtained in our experiments are mainly limited by photon statistics while crosstalk, electronic noise and signal bandwidth have relatively little influence.

The possibility has been investigated of determining, using graydar (Gamma RAY Detection And Ranging)approach, the in-depth partial-density profile of some substance absorbed in a dense medium. Analyticalalgorithms have been derived for retrieving the in-depth profile of the partial density of the absorbed substanceon the basis of the conjecturally known in-depth profile of the extinction of the absorbing medium and theexperimentallydeterminablegraydarprofile. TheretrievalerrorunderthePoissonnoiseconditionshasalsobeenestimated analytically. The simulations performed of the Poisson-noise effect concern the case of soil moisture.The results obtained confirm the validity of the derived retrieval algorithms and error estimates and show thatthesoilmoistureprofilemaybeaccuratelydeterminedtodepthsof50cm,dependingonthedry-soilbulkdensity,thesensingphotonflux,andthemeasurementtime.PACSnumbers:07.85.

This paper describes a study of background estimation in Modular X- and Gamma ray Sensor (MXGS) onboard ESA's Atmosphere-Space Interactions Monitor (ASIM) mission, using Geant4 simulations and Spenvis packages for particle flux generations.

A transportable and robust gamma ray detection system (GISPI) was employed to determine the concentrations of naturally occurring radionuclides on various beaches in and around Saldanha Bay, located on the West Coast of South Africa. Several mathematical techniques were applied to obtain GIS overlay that could be used to investigate various geophysical phenomenon. The results demonstrated direct relationships between radionuclide concentrations, grain size of beach sediment and the intensity of wave action. The element concentrations were used to make deductions on the origin of some of the beach sand. The article finally draws conclusions on coastal and beach formation processes, based on the results of the distribution of various radionuclides.

In the present research the quality of 18F-FDG (fluorodeoxyglucose) is maintained to reduce hazards of the patients and produce good quality of image that helps interpret the image with proper diagnosis. The quality of produced 18F-FDG in the United Hospital, Bangladesh is checked in the quality control laboratory and compared with the guideline criteria of the International Atomic Energy Agency. This 18F-FDG has been injected into 2500 patients and found no immediate or afterward hazards to any patients till now. Radionuclide purity, radiochemical purity, chemical purity, pH are assessed to have the quality assurance of 18F-FDG studied. Radionuclide purity is validated by half-life measurement and gamma ray detection. The calculated average half-life (110.26 min) and halflife 18F (109.7 min) are found in good agreement. The peak from TLC result sheet gives only the peak of unhydrolyzed FDG which implies more than 99% 18F-FDG is evident in this experiment. Chromatographic spectrum of residual solvents like Acetonitrile and Ethanol are analyzed to access the chemical purity with respect to permissible concentration. The pH of 18F-FDG is found within 4.5 to 6.5.

The performance of hand-held radioisotope identification devices (RIDs) is still hampered by the performance of the NaI(Tl) detectors, which are commonly used in such instruments. In this paper, we continue the search for better detector options. One of the largest single elements ever made, a coplanar CdZnTe (CZT) detector (30times15times12.1 mm3 volume 5.45 cm3 designed by University of Michigan) is compared with a commercially available LaBr3(Ce) detector (ominus1''times1'' volume 12.9 cm3.) Parameters that are relevant to the performance of isotope identification devices, such as resolution and efficiency as function of the gamma-ray energy, temperature shift, linearity and others are measured and compared. According to measurement results, it seems that for this application LaBr3(Ce) detectors are a viable alternative to CZT detectors; even more so if one bears in mind that LaBr3(Ce) became commercially available only recently and detectors with larger volumes are likely to appear in the near future

Some examples of space-borne applications that require improvements in detector technology compared with conventional Si and Ge designs are described. Properties of compound semiconductors are noted, and a range of different detector developments are briefly reviewed. Material fabrication improvements for several compound semiconductors have resulted in near Fano-limited performance.

The detection of high-energy γ-ray sources is vitally important to national security for numerous reasons, particularly nuclear materials smuggling interdiction and threat detection. This article presents two methods of detecting and locating a concealed nuclear γ-ray source by analyzing detector data of emissions that have been modulated with a coded mask. The advantages of each method, derived from a simulation study and experimental data, are discussed. Energetic γ-rays readily penetrate moderate amounts of shielding material and can be detected at distances of many meters. Coded masks are spatial configurations of shielding material (e.g., small squares formed from plates of lead or tungsten) placed in front of a detector array to modulate the radiation distribution. A coded mask system provides improved detection through an increased signal-to-noise ratio. In a search scenario it is impossible to obtain a comparison background run without the presence of a potential concealed source. The developed an...

We discuss the silicon photomultiplier as a novel photon detector for the Major Atmospheric Gamma Imaging Cerenkov Telescope and the Extreme Universe Space Observatory. For these astroparticle experiments we pursue two different developments of the SiPM. One development is pursued at MEPhI, where prototypes are available. In the course of this paper we will describe some characteristics of these devices. The second development, which is using the back illumination principle is at present in its design phase.

A prototype gamma radiation monitoring system based on In/sub 2/O/sub 3//SiO thick-film sensors array was designed. Four sensors had an identical pn-heterojunction structure with different material compositions. These sensors were subjected to gamma radiation emitted by /sup 137/Cs source with an activity of 370 kBq. Changes in their current-voltage characteristics were recorded and compared. The performance parameters of the devices, such as sensitivity to /spl gamma/ radiation exposure and working dose region, were found to be highly dependent on the composition of the materials used. To cover a wider range of radiation and improve the overall sensitivity, an approach of using sensor arrays was utilized. A dynamic selection of the multiple sensors of various sensitivities and working dose ranges was implemented by applying a pattern recognition analysis.

The performance characteristics of Frisch-ring CdZnTe (CZT) detectors are described and compared with other types of CZT devices. The Frisch-ring detector is a bar-shaped CZT crystal with a geometrical aspect ratio of /spl sim/1:2. The side surfaces of the detector are coated with an insulating layer followed by a metal layer deposited directly upon the insulator. The simple design operates as a single-carrier device. Despite the simplicity of this approach, its performance depends on many factors that are still not fully understood. We describe results of testing several detectors fabricated from CZT material produced by different vendors and compare the results with numerical simulations of these devices.

A phoswich detector composed of a thin plate CsI(Tl) scintillator and a plastic scintillator (BC-400) has been designed and evaluated in order to improve the sensitivity in the low-energy region of a large-area plastic scintillation detector. This newly designed phoswich detector can be applied to both gross gamma measurement and energy spectrometry for low-energy gamma-ray emitters. Judging by estimations of minimum detectable activity, the lower measurable energy of a large-area plastic scintillation detector can be expanded down to a few tens of keV by adding a thin plate CsI(Tl) scintillator.

TlBr crystals, grown by hydrothermal and "Bridgman-Stockbarger" methods, were investigated as potential single and pixel detectors of X- and gamma radiation. Technology of detectors manufactured from TlBr crystals is reported. The spectra of the radionuclides Fe-55, Am-241, Cd-109, Co-57, and Cs-137, measured by single TlBr detectors are presented. Full-width at half-maximum (FWHM) energy resolutions of 500 eV at 5.9 keV; 518 eV at 9.87 keV; 670 eV at 13.92 keV; 777 eV at 22.1 keV; 2.7 keV at 59.5 keV; 3.7 keV at 88 keV; 4.4 keV At 122 keV, and 29 keV at 662 keV have been achieved. Small format (3/spl times/3) pixel detectors with pads 0.35/spl times/0.35 mm and gap 0.1 mm were also fabricated on single TlBr crystals of dimensions 2.7/spl times/2.7/spl times/1.0 mm/sup 3/. The interpixel resistivities measured at a bias of 50 V were 400-600 GOhm. The pixel leakage currents at a bias of 250 V were typically less than 0.5 nA. The best spectra were obtained at a temperature of -30/spl deg/C, a shaping time constant of 6 /spl mu/s and high voltage of 400 V. Energy resolutions of 2.2, 3.0, 3.7 and 29 keV were measured at input energies of 59.5, 88, 122, and 662 keV, respectively. Values of /spl mu//spl tau/ have been evaluated for two different ingots produced by the "Bridgman-Stockbarger" method. They are /spl mu//sub e//spl tau//sub e/=2.5/spl times/10/sup -4/ cm/sup 2/ V/sup -1/ and /spl mu//sub h//spl tau//sub h//spl sim/10/sup -6/ cm/sup 2/ V/sup -1/ for one ingot at -30/spl deg/C and /spl mu//sub e//spl tau//sub e/=7/spl times/10/sup -5/ cm/sup 2/ V/sup -1/, and /spl mu//sub h//spl tau//sub h/=1.5/spl times/10/sup -5/ cm/sup 2/ V/sup -1/ for the other ingot at -10/spl deg/C.

A miniature radiation monitor (MRM) device has been developed, which utilizes a charge-coupled device (CCD) as its sensitive element. Its shielding configuration has been designed to mitigate the displacement damage threat in space environments, while also introducing a good degree of directional sensitivity.

The gamma ray detection efficiency of two HPGe detectors for off-center points was measured both on the detector's cap and outside the detector's cap. It was found that similar to measurements on the detector symmetry axis, for off-center measurements including those outside the detector cap also, the detector could be treated as an effective point detector. The virtual point detector was found to be almost at the same position for vertical and horizontal source displacements.

This paper studies the effect of lead wrapping on the response of the plastic scintillators as gamma detectors. Experimental tests and Geant4 simulations showed that lead wrapping cannot increase the gamma absorption efficiency of the detector but, as a reflector, it can improve the optical properties of the detector. The reflectivity of the lead foil as an optical reflector was determined equal to 66% using an experimental-simulation combined method. Based on the obtained results, the optical collection efficiency of the detector was also increased about 4% after employing the lead reflector.

Currently we are investigating the inclusion of organotin compounds in new polystyrene scintillator materials to improve full gamma-ray energy sensitivity. Accurate calibration of the relative light yield from the newly developed scintillators is crucial to assess merits of compounds and chemical processes used in the scintillators' development. The full energy gamma-ray peak in a measured gamma-ray spectrum is commonly used in calibrating the relative light yield. However, the Compton continuum in the newly developed plastic scintillators is measured with much better efficiency and statistics and is found to be the best spectral feature that can be exploited for expeditious calibration of the relative light yield. In this study, we present a spectral gain matching of measured and simulated spectra, using a spectrum rebinning technique, to determine the Compton edge in a measured Compton continuum for accurate relative light yield calibration. The Compton edges determined using this technique were found to be within 1.2% of their theoretical estimates.

The solution to the scatter problem remains a major technical challenge in gamma ray imaging. This paper presents a modelization of apparent images formed by scattered photons at various energies. It may be used either to generate a series of realistic multi-energy images or be included in an image enhancement procedure. The application to SPECT is discussed.

The clinically oriented NEMA NU-2 2000+ performance standards have been performed on an ADAC molecular coincidence detection dual-head camera. At 1 cm radius, the transverse resolution full-width at half-maximum was measured to be 5.2 (10.0) mm and the axial was 5.0 (10.6) mm. At 10 cm radius, the transverse radial resolution was 4.7 (7.4) mm and the transverse tangential was 8.5 (20.9) mm. The axial resolution was 14.0 (41.1) mm. The peak true count rate was 4370 counts/s at a concentration of 4.3 kBq/ml. The peak noise equivalent count rate (NECR) was 1620 counts/s at 2.9 kBq/ml. The system scatter fraction was 48%, The maximum relative count rate error observed at the NECR peak was -42%. The sensitivity was 1010 counts/sm/rSq in the center and 870 counts/s/MBq at an offset of 10 cm. The contrast for the hot spheres ranged from 18.5 (11.6)% to 11.6 (7.9)% for a contrast ratio of 8:1 (4:1). For the cold spheres, it ranged from 41% to 25% with an overall background variability of 7%. The residual error in scatter and attenuation correction was approximately 50%. All measurements were performed at the maximum allowed crystal-to-crystal distance of 810 mm.

The purpose of this work is to determine very precisely the relative detection efficiency curve for high purity germanium γ-ray detector. We used the method that Hawari and Fleming reported in Nucl. Instrum. Methods (A353, 106 (1994)). Measurement was carried out at a source-to-detector distance of 40 cm for 24Na, 46Sc, 48Sc, 60Co, 88Y, 94Nb and 108Ag sources. The relative detection efficiencies were fitted by a third-order polynomial function with the expected variance of about 0.2% from 430 to 2,750 keV.

A multiwire ionisation chamber filled with liquid xenon as a position sensitive detector for Positron Emission Tomography is studied. Both xenon scintillation, which provides a fast trigger, and ionisation charge for position and energy measurements are read. The detection efficiency of the detector is assessed in separate measurements of the probability of detection of the scintillation light and the charge signals due to 511 keV gamma-rays. These were measured to be about 1 and 0.82, respectively.

Despite its intrinsic advantages as a sensor material for the detection of gamma and X radiation, CdTe has proven a difficult material to produce consistently and in sufficient quantities. We report further developments of a vapour phase technique, which has provided significant advantages over current melt growth technologies. Crystals of up to 50 mm in diameter have been produced with increased growth rates up to 12 mm/day

It was found that IR illumination of a properly chosen wavelength and intensity can significantly improve spectrometric characteristics of CdZnTe quasi-hemispherical detectors [1]. Improving of the spectrometric characteristics is due to improvement of uniformity of charge collection by the detector volume. For operation at room temperature the optimal wavelength of IR illumination is about 940 nm, but for operation at lower temperature of -20 °C the optimal wavelengths of IR illumination is about 1050 nm. Infrared illumination can be performed using conventional low-power IR LEDs. Application of SMD LEDs allows produce miniature detection probes with IR illuminated CdZnTe detectors. We have fabricated and tested a variety of detection probes with CdZnTe quasi-hemispherical detectors from the smallest with volumes of 1-5 mm3 to larger with volumes of 1.5 cm3 and 4.0 cm3. The use of IR illumination significantly improves spectrometric characteristics of the probes operating at room temperature, especially probes with detectors of large volumes. The probe with the detector of 4 cm3 without IR illumination had energy resolution of 24.2 keV at 662 keV and of 12.5 keV with IR illumination.

Describes the unprecedented implementation of "in-flight" reconfigurable on-board data handling electronics using reprogrammable FPGA (field programmable gate array) technology. The electronics design was realized for a prototype of the Imager for the INTEGRAL mission that is an ESA "Horizon 2000" long term plan, now in the second selection cycle (M2). The Imager prototype was developed by an international collaboration, and was flown successfully on a balloon from Fort-Sumner, New Mexico in October 1993. The purpose of this reconfigurable electronics was to demonstrate a new engineering approach that would reduce the cost of mass and power of the payload. The accomplishment of using a flexible structure in an instrument prototype combined with the demonstration of high performance during hostile environmental flight conditions is presented. >

We investigated the feasibility of long-drift-time CdZnTe (CZT) gamma-ray detectors, fabricated from CZT material produced by Redlen Technologies. CZT crystals with cross-section areas of 5 5 mm2 and 6 6 mm2 and thicknesses of 20-, 30-, 40-, and 50-mm were configured as 3D position-sensitive drift detectors and were read out using a front-end ASIC. By correcting the electron charge losses caused by defects in the crystals, we demonstrated high performance for relatively thick detectors fabricated from unselected CZT material. VC 2016 AIP Publishing LLC.

For non-destructive inspection of relatively massive objects, hard X-ray or gamma-ray of a few hundred keV can be used so that the ray penetrates the target objects. In this energy region, detection of the ray is difficult compared to the one less than ~100keV. To establish electronic readout of large-area gamma-ray imaging, we have developed a GEM-based imaging sensor. The system overview and results of hard X-ray imaging tests are reported.

The accurate dose determination for gamma ray fields is considered, a p-i-n diode is taken as the basic detector for the implementation of a gamma ray monitor. This determination is fundamental for a further application in the evaluation of dose from photon fields generated for medical applications in Radiotherapy with LINAC's.

Proof-of-principle of a novel gamma-ray imaging system has been performed by Monte Carlo simulation. Previous designs implement either a coded aperture or Compton scattering system to image a gamma-ray source. By taking advantage of characteristics of each of these systems a new design can be implemented that does not require a pixelated stopping detector. This new system has significant promise in homeland security, astronomy, medical imaging and other fields.

A new trace-element quantification method has been developed by combining multiple gamma-ray detection and neutron activation analysis. This method is characterized by high sensitivity and simultaneous analysis for multi-elements. It has been successfully applied to the analyses of igneous rock samples, long-lived radionuclide, 129I, and geologic samples. Future perspectives for an innovative pulsed neutron source and a new detector system will be presented.