The detection efficiency of cosmic gamma-ray sources and limits on the discrete source flux

1984 ◽  
Vol 10 (11) ◽  
pp. 1587-1598 ◽  
Author(s):  
B P Houston ◽  
A W Wolfendale
1993 ◽  
Vol 302 ◽  
Author(s):  
Michael R. Squillante ◽  
Herbert Cole ◽  
Peter Waer ◽  
Gerald Entine

ABSTRACTThe use of cadmium telluride (CdTe) semiconductor nuclear detectors is continuing to expand into new areas because of their unique properties which include room temperature operation and high detection efficiency. In addition, they remain the material of choice in many critical applications such as nuclear medicine and power plant monitoring because of their reputation for reliability and long term stability1. CdTe is by far the most developed of the compound semiconductors used in nuclear detector applications and it offers a number of significant benefits to researchers, clinicians and engineers who have special requirements relating to size, sensitivity and operating temperature.Recently, there have been improvements in the growth of the crystalline material and in the fabrication procedures which have resulted in better performance and in the ability to produce arrays. This article describes the physical and electronic properties of CdTe nuclear detectors, discusses how the crystal growth and device fabrication procedures can affect these properties, and compares the performance to CdZnTe detectors.


2019 ◽  
Vol 5 (2) ◽  
Author(s):  
He Li-xia ◽  
Hao Xiao-yong ◽  
He Gao-kui

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%).


2014 ◽  
Vol 03 (02) ◽  
pp. 1440008 ◽  
Author(s):  
M. Beilicke ◽  
F. Kislat ◽  
A. Zajczyk ◽  
Q. Guo ◽  
R. Endsley ◽  
...  

X-ray polarimetry promises to give qualitatively new information about high-energy astrophysical sources, such as binary black hole systems, micro-quasars, active galactic nuclei, neutron stars, and gamma-ray bursts. We designed, built and tested a X-ray polarimeter, X-Calibur, to be used in the focal plane of the balloon-borne InFOCμS grazing incidence X-ray telescope. X-Calibur combines a low-Z scatterer with a Cadmium Zinc Telluride (CZT) detector assembly to measure the polarization of 20–80 keV X-rays making use of the fact that polarized photons scatter preferentially perpendicular to the electric field orientation. X-Calibur achieves a high detection efficiency of ≃80%. The X-Calibur detector assembly is completed, tested, and fully calibrated. The response to a polarized X-ray beam was measured successfully at the Cornell High Energy Synchrotron Source. This paper describes the design, calibration and performance of the X-Calibur polarimeter. In principle, a similar space-borne scattering polarimeter could operate over the broader 2–100 keV energy band.


2020 ◽  
Vol 57 (1-2) ◽  
pp. 13-21 ◽  
Author(s):  
A.A. Bogdanov ◽  
E.E. Kholupenko ◽  
Yu.V. Tuboltsev ◽  
Yu.V. Chichagov

AbstractA novel cluster of sensitive detectors based on silicon photomultipliers (SiPM) is being developed for the Cherenkov gamma-ray telescope TAIGA-IACT (Tunka valley, Republic of Buryatia, Russia). The cluster will be able to detect Cherenkov radiation from extensive air showers in two wide bands: 250–300 nm (UV) and 250–700 nm (visible and UV). Each pixel consists of a Winston cone, 4 SiPMs with the total sensitive area of 144 mm2, and readout electronics based on fast analogue memory. During operation in the UV band, a UV-bandpass filter is used to suppress cluster sensitivity in the visible range. In order to evaluate the detection efficiency of the selected SiPMs, a specific software simulator of SiPM output signal has been developed. This simulator takes into account such inherent parameters of SiPMs as total number of microcells, their recharge time, the dark count rate, the effective detection area, the quantum efficiency, the crosstalk between microcells, as well as conditions of SiPM operation, namely, the background noise and the Ohmic load in the readout (front-end) electronics. With this simulator it is possible to determine the expected trigger threshold under given conditions and parameters of selected detectors. Based on preliminary simulations, OnSemi MicroFJ-60035 SiPM chips have been chosen for the novel cluster of TAIGA-IACT. These SiPMs have sensible efficiency in the ultraviolet range (5–20% in the 250–300 nm band) and are distinguished by the presence of a fast output, which allows one to capture a low amplitude signal above a relatively high background noise.


2019 ◽  
Vol 30 (11) ◽  
pp. 1950099
Author(s):  
I. V. Prozorova ◽  
R. R. Sabitova ◽  
N. Ghal-Eh ◽  
S. V. Bedenko

The response function is the important information for the precise interpretation of experimental data and also for characterizing the developing nuclear instruments. Measurement of the response function normally requires a number of mono-energetic gamma-ray sources, a long acquisition time and an appropriate experimental setup. The Monte Carlo method, as an alternative to response function measurement, has widely been used and recommended. In this study, a computational model of an HPGe detector has been developed by using the MCNP5 code. To validate the simulated model, the simulations from mono-energetic sources have been compared to the corresponding measured data. Any deviation from the measurement could be attributed to the unmodeled details of the detector crystal, so they needed adjustment. Moreover, an analysis has been undertaken on the dependency of detection efficiency on the dead layer thickness of the germanium crystal. Having developed a computational model of the crystal, a set of correction factors was extracted to take into account the gamma-ray self-absorption within the source volume. The simulated model of the HPGe detector in this study can be used to calculate the detection efficiency when the samples are not of the standard geometry which require self-absorption considerations.


2022 ◽  
Vol 17 (01) ◽  
pp. C01001
Author(s):  
F. Ahmadov ◽  
G. Ahmadov ◽  
R. Akbarov ◽  
A. Aktag ◽  
E. Budak ◽  
...  

Abstract In the presented work, the parameters of a new MAPD-3NM-II photodiode with buried pixel structure manufactured in cooperation with Zecotek Company are investigated. The photon detection efficiency, gain, capacitance and gamma-ray detection performance of photodiodes are studied. The SPECTRIG MAPD is used to measure the parameters of the MAPD-3NM-II and scintillation detector based on it. The obtained results show that the newly developed MAPD-3NM-II photodiode outperforms its counterparts in most parameters and it can be successfully applied in space application, medicine, high-energy physics and security.


2018 ◽  
Vol 13 (05) ◽  
pp. P05019-P05019 ◽  
Author(s):  
S. Ahmadi ◽  
S. Ashrafi ◽  
F. Yazdansetad

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