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Instrumentation effects on U and Pu CBNM standards spectra quality measured on a 500 mm <sup>3</sup> CdZnTe and a 2×2 inch LaBr <sub/>3</sub> detectors
摘要： Nowadays, there is interest in developing gamma-ray measuring devices based on the room temperature operated medium resolution detectors such as semiconductor detectors of the CdZnTe type and scintillators of the LaBr3 type. This is true also for safeguards applications and the International Atomic Energy Agency (IAEA) has launched a project devoted to the assessment of medium resolution gamma-ray spectroscopy for the verification of the isotopic composition of U and Pu bearing samples. This project is carried out within the Non-Destructive Assay Working Group of the European Safeguards Research and Development Association (ESARDA). In this study we analyze medium resolution spectra of U and Pu standards with the aim to develop an isotopic composition determination algorithm, particularly suited for these types of detectors. We show how the peak shape of a CdZnTe detector is influenced by the instrumentation parameters. The experimental setup consisted of a 500 mm3 CdZnTe detector, a 2x2 inch LaBr3 detector, two types of measurement instrumentation – an analogue one and a digital one, and a set of certified samples – a 207Bi point source and U and Pu CBNM standards. The results of our measurements indicate that the lowest contribution to the peak asymmetry and thus the smallest impact on the resolution of the 500 mm3 CdZnTe detector was achieved with the digital MCA. Analysis of acquired spectra allowed to reject poor quality measurement runs and produce summed spectra files with the least impact of instrumentation instabilities. This work is preliminary to further studies concerning the development of an isotopic composition determination algorithm particularly suited for CZT and LaBr3 detectors for safeguards applications.
关键词： LaBr3,isotopic composition,uranium enrichment,medium resolution,safeguards,CdZnTe
更新于2025-09-23 15:23:52
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Study on Thallium bromide Radioactive Detector
摘要： Thallium bromide (TlBr) is a compound semiconductor material, which can be used for X-ray and gamma-ray detectors and can be used at room temperature. It has excellent physical properties, high atomic number and density, wide bandgap (B=2.68 eV), and low ionization energy. Compared with other X-ray and gamma-ray detection materials, TlBr devices have high detection efficiency and excellent energy resolution performance. So TlBr is suitable for housing in small tubes or shells, and it can be widely used in nuclear material measurement, safeguards verification, national security, space high-energy physics research and other fields. Based on the fabrication of TlBr prototype detector, this paper focuses on the device fabrication and signal acquisition technology. Gamma-ray spectrum measurements and performance tests are carried out with AM-241 radioactive source. The results show that the special photoelectric peak of 59.5 keV is clearly visible, and the optimal resolution is 4.15 keV (7%).
关键词： Compound semiconductor,Safeguards verification,TlBr detector
更新于2025-09-23 15:22:29
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[IEEE 2017 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC) - Atlanta, GA (2017.10.21-2017.10.28)] 2017 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC) - SPECT Reconstruction and Analysis for the Inspection of Spent Nuclear Fuel
摘要： A gamma-emission-tomography (GET) system for the inspection of spent nuclear fuel (SNF) has been developed and tested on multiple fuel types. This tool can be used for verification of the integrity of an assembly and consistency with fissile-material content. Parallel-beam line integrals are measured by a discrete array of CdZnTe detectors that view the fuel through a 1.5mm wide by 100mm thick tungsten collimator. Detectors and electronics are on a rotating platform within a watertight stainless steel torus. During operation, the system is underwater and fuel is lowered through the center of the torus and held stationary as data are collected. Tomographic data collection requires a time on the order of minutes. In field experiments, data with count rates in the range of 50kcps to >500kcps per pixel have been recorded. In the reconstructed images, missing or replaced pins in all assembly types can be visually discriminated in the lattice of fuel pins. Automated detection of missing/replaced pins is the metric used for determination of optimal processing steps. Effectiveness of reconstruction and data-processing tools is measured by a tools ability to improve performance on the pin-discrimination task. This paper describes the data preprocessing, image reconstruction, image analysis, and performance evaluation of this system.
关键词： gamma-ray emission tomography,image quality metrics,safeguards,attenuation correction,image reconstruction,spent nuclear fuel
更新于2025-09-09 09:28:46