A test device for isotopic γ-ray imaging with CdZnTe detector

A test device for isotopic γ-ray imaging, which consists of an isotope γ-ray source, a CdZnTe γ-ray spectrometer and other auxiliary equipment, is studied here. Compared with the conventional X-ray, the isotope γ-ray, which is utilized in this project, has its own advantages in imaging. Furthermore, with a room-temperature high-energy-resolution CdZnTe detector and a modem imaging processing technique, this device is capable of effectively suppressing the background and gaining more information, thus it can obtain a better image than conventional X-ray devices. In the experiment of PCB imaging, all soldered points and chip components are sharply demonstrated.     

Use of TlBr crystals for x- and γ-ray detectors

The development and investigations of uncooled semiconductor x- and γ-ray detectors based on thallium bromide crystals grown by the Bridgman–Stockbarger method are reported. The procedure for preparing Me–TlBr–Me (Me = Au, In) detector structures is described, and the current–voltage characteristics are investigated. The counting and spectrometric characteristics of the detectors fabricated have been measured. The best energy resolution was 0.54, 1.3, 1.41, 2.1, and 7.1 keV at energy 5.8 (⁵⁵Fe), 22.1 (¹⁰⁹Cd), 59.6 (²⁴¹Am), 122 (⁵⁷Co), and 662 keV (¹³⁷Cs), respectively. Translated from Atomnaya énergiya,Vol. 106, No. 4, pp. 214–217, April, 2009.     

Methods for obtaining characteristic γ-ray net peak count from interlaced overlap peak in HPGe γ-ray spectrometer system

For a characteristic c-ray with interlaced overlap peak, and the case where its reliable and credible net count cannot be obtained using the current high-purity germanium(HPGe) multichannel γ-ray spectrum software, two new methods are proposed herein to obtain the γ-ray net peak count from the interlaced overlap peak in the HPGe cray spectrometer system, of which one is the symmetric conversion method based on Gaussian distribution and the other is where the energy average value of two close γ-rays is regarded as the γ-ray energy. The experimental results indicate that the two methods mentioned above are reliable and credible. This study is significant for the development of better γ-ray spectrum processing software for measuring complex γ-ray spectra concerning the nuclear reaction cross section, neutron activation analysis, and analysis of transuranium elements, using an HPGe detector.     

Development of a γ-ray Measurement System of Radioactive Wastes

According to the criteria of radioactive wastes, intermediate and low-level radioactive solid waste produced in nuclear fuel recycle must be characterized for near surface disposed. For this purpose, a     

Development of a γ-ray Measurement System of Radioactive Wastes

According to the criteria of radioactive wastes, intermediate and low-level radioactive solid waste produced in nuclear fuel recycle must be characterized for near surface disposed. For this purpose, a special y-ray measuring system used for classifying low or medium-density drummed radioactive wastes was developed. The system consists of three sets of high purity germanium detectors with multi-channel analyzers. When the system works, waste drums rotate on axial and divided into three segments on radial.     

Proposal for a high brightness γ-ray source at the SXFEL

High brightness γ-rays produced by laser Compton scattering(LCS) are ideal probes for the study of nucleon and nuclear structure. We propose such a γ-ray source using the backscattering of a laser from the bright electron beam produced by the linac of the Shanghai Soft X-ray Free-electron Laser(SXFEL) test facility at the Shanghai Institute of Applied Physics(SINAP). The performance is optimized through theoretical analysis and benchmarked with 4D Monte-Carlo simulations. The peak brightness of the source is expected to be larger than2 × 1022photons/(mm2mrad2s 0.1%BW) and photon energy ranges from 3.7 Me V to 38.9 Me V. Its performance, compared to Extreme Light Infrastructure-Nuclear Physics(ELI-NP), and the Shanghai Laser-Electron Gamma-ray Source(SLEGS), is given. The potential for basic and applied research is also briefly outlined.     

Study on the performance of a large-size Cs I detector for high energy γ-rays

The measurement of high-energy γ-rays is an important experimental method to study the giant resonance in a nucleus, c reaction in nuclear astrophysics, and so on. The performance of a large-size Cs I detector for crays detection is studied by comparison between the experimental measurements and GEANT4 simulation. The reliability of the simulated efficiency for low-energy γ-rays is verified by comparing with the experimental data. The efficiency of the Cs I detector for high-energy γ-rays was obtained by the GEANT4 simulation. The simulation shows that the detection efficiency of 20 Me V γ-rays can reach 3.8%.     

A VMEbus interface for multi—detector trigger and control system

MUSE（MUltiplicity SElector)is the trigger and control system of CHIMERA,a 4π charged particles detector.Initialization of MUSE can be performed via VMEbus.This paper describes the design of VMEbus interface and functional module in muse,and briefs an application of MUSE.     

Design of Graphite-wall Ionization Chamber as Air-kerma Standard for γ-ray

<正>The graphite-wall ionization chamber which is based on Bragg-Gary cavity theory is used as air-kerma primary standard for ~(137)Cs and ~(60)Coγ-ray reference radiation.     

Lithium-7 Dosimeter Glass for Simultaneous Measurement of Thermal Neutron and Coexisting γ-ray Dose

This paper describes a method of evaluating the effectiveness of cylindrical control rods for the general case where multiple control rods of various effective lengths affecting epithermal and thermal neutrons are arbitrarily distributed and partially inserted to mutually independent positions in a reflected reactor. This method is a generalization of the technique introduced by Nordheim &; Scalettar (N-S method), employing the two-group, three-dimensional diffusion theory with modified application of the boundary condition imposed on the surface of control rods.

Either the multiplication constant or the prompt neutron decay constant can be designated as eigen-value of the system. Moreover, vector-matrix notations are employed to faciliate the treatment of the problems and the subsequent derivation of the critical determinant.

The general problem based on the asymmetrical arrangement of control rods can be reduced to a number of special cases to find out the order of the critical determinant. We discuss the imitations of the modified N-S method. Finally, we perform numerical studies and compare the calculated results with experimental data based upon the pulsed neutron source method.     

Measurement of keV-neutron capture cross-sections and capture γ-ray spectra of Fe and Fe

The neutron capture cross-sections and the capture γ-ray spectra of ⁵⁶Fe and ⁵⁷Fe have been measured in the neutron energy range from 10 to 90 keV. Pulsed keV-neutrons were produced from the ⁷Li(p,n)⁷Be reaction by bombarding a lithium target with a 1.5-ns bunched proton beam from a 3 MV Pelletron accelerator. The incident neutron spectrum on the capture sample was measured using a time-of-flight method with a ⁶Li-glass detector. The capture γ-rays emitted from an iron or standard gold sample were detected with a large anti-Compton NaI(Tl) spectrometer. The capture yield of the iron or gold sample was obtained by applying a pulse-height weighting technique to the corresponding capture γ-ray pulse-height spectrum. The capture cross-sections of ^56,57Fe were derived with errors less than 5% using the standard capture cross-sections of ¹⁹⁷Au. The capture γ-ray spectra were obtained by unfolding the observed capture γ-ray pulse-height spectra. The present results for the capture cross-sections were compared with the previous measurements and the evaluated values of ENDF/B-VII.0 and JENDL-3.3. The Maxwellian-averaged capture cross-sections of ⁵⁶Fe and ⁵⁷Fe at 30 keV are derived as 12.22 ± 2.06 mb and 44.48 ± 7.56 mb, respectively.     

The Sub-Library of Giant Dipole Resonance Parameters for γ-ray (CENPL-GDP-1.1) (Ⅱ)

In this paper, the experimental data of the photonuclear reactions for the nuclides ~(12)C, ~(14)N, ~(16)O, ~(27)Al and ~(28)Si were fitted with the Lorentz curves describing the giant dipole resonances of the photonuclear reactions and the giant dipole resonance parameters (GDRP) of these nuclides were extracted. These GDRP were compiled in the sub-library of the giant dipole resonance parameters for γ-ray(GDP). An updated edition GDP-1.1(Version 1.1) has been set up and used in the nuclear model calculation widely.     

Performance of multigap resistive plate chamber in a γ-ray aging test

1 Introduction MRPC is a new type of gas detector [1, 2] devel- oped in the last few decades. It has been proposed to be a substitute for the Time of Flight (TOF) detector used in conventional technology in high-energy nu- clear and particle experiments because of its properties of excellent time resolution, high efficiency, simple structure, insensitivity to magnets, and low energy dissipation. The MRPC technology has been adopted for TOF by the STAR group at Relativistic Heavy Ion C…