A Ge(Li) COUNTER INVESTIGATION OF THE GAMMA-RAY DECAY OF 28Si PRODUCED IN THE REACTION 27Al(p, γ)28Si

1966 ◽  
Vol 44 (12) ◽  
pp. 3075-3081 ◽  
Author(s):  
R. E. Azuma ◽  
L. E. Carlson ◽  
A. M. Charlesworth ◽  
K. P. Jackson ◽  
N. Anyas-Weiss ◽  
...  
Keyword(s):  
Gamma Ray ◽  
Germanium Detector ◽  
Detailed Account ◽  
Γ Ray ◽  
Proton Resonances ◽  
Reaction 27Al

A large (17 cm3) lithium-drifted germanium detector has been used to observe the γ-ray deexcitation of 28Si produced at several proton resonances in the 27Al (p, γ)28Si reaction. The decay schemes have been deduced and compared with those previously published. In the present paper a detailed account is given for the Ep = 992-keV resonance only.

scholarly journals Validation of EFFTRAN for efficiency transfer to distant geometries and volume sources

2021 ◽  
Author(s):  
H. Ramebäck ◽  
S. Jonsson ◽  
T. Vidmar
Keyword(s):  
Methyl Methacrylate ◽  
Gamma Ray ◽  
Germanium Detector ◽  
Gamma Ray Spectrometry ◽  
Volume Source ◽  
Two Stage ◽  
Poly Methyl Methacrylate ◽  
Fit For Purpose

AbstractThe efficiency transfer procedure from a geometry where a volume source was placed directly on the endcap of a germanium detector to three different distant geometries was carried out using the EFFTRAN code. One of these distant geometries included absorbers consisting of poly(methyl methacrylate). The efficiency transfer to this geometry therefore had to be realized as a two-stage transfer, since a direct efficiency transfer is not possible using EFFTRAN in such a case. Efficiency transfer to all three distant geometries yielded results which can be considered as fit-for-purpose in e.g. most of the applications of gamma ray spectrometry.

scholarly journals Gamma-Ray Imaging of the Galactic Center Region

1989 ◽  
Vol 136 ◽  
pp. 581-585
Author(s):  
W. R. Cook ◽  
D. M. Palmer ◽  
T. A. Prince ◽  
S. M. Schindler ◽  
C. H. Starr ◽  
...  
Keyword(s):  
Gamma Ray ◽  
Galactic Center ◽  
Coded Aperture ◽  
Center Region ◽  
Gamma Ray Imaging ◽  
The Galaxy ◽  
Γ Ray ◽  
Luminous Objects

The Caltech imaging γ-ray telescope was launched by balloon from Alice Springs, NT, Australia and performed observations of the galactic center during the period 12.62 to 13.00 April 1988 UT. The first coded-aperture images of the galactic center region at energies above 30 keV show a single strong γ-ray source which is located 0.7±0.1° from the galactic nucleus and is tentatively identified as 1E1740.7-2942. If the source is at the distance of the galactic center, it is one of the most luminous objects in the galaxy at energies from 35 to 200 keV.

scholarly journals Molecular Clouds Observed by the EGRET Gamma-Ray Telescope

1997 ◽  
Vol 170 ◽  
pp. 22-24 ◽  
Author(s):  
Seth. W. Digel ◽  
Stanley D. Hunter ◽  
Reshmi Mukherjee ◽  
Eugéne J. de Geus ◽  
Isabelle A. Grenier ◽  
...  
Keyword(s):  
Molecular Mass ◽  
Molecular Clouds ◽  
Gamma Ray ◽  
Angular Resolution ◽  
Cosmic Ray ◽  
High Energy ◽  
Background Rejection ◽  
Γ Rays ◽  
Γ Ray ◽  
Production Mechanisms

EGRET, the high-energy γ-ray telescope on the Compton Gamma-Ray Observatory, has the sensitivity, angular resolution, and background rejection necessary to study diffuse γ-ray emission from the interstellar medium (ISM). High-energy γ rays produced in cosmic-ray (CR) interactions in the ISM can be used to determine the CR density and calibrate the CO line as a tracer of molecular mass. Dominant production mechanisms for γ rays of energies ∼30 MeV–30 GeV are the decay of pions produced in collisions of CR protons with ambient matter and Bremsstrahlung scattering of CR electrons.

scholarly journals Using Gamma Spectroscopy to Calculate Radioactive Contaminants in Foreign and Local Tobacco Samples

2020 ◽  
Vol 55 (2) ◽  
Author(s):  
Ahmed F. Mkhaiber ◽  
Auday T. Al-Bayati ◽  
Enas A. Jawad ◽  
Khalid H. Mahdi
Keyword(s):  
Gamma Ray ◽  
Specific Activity ◽  
Gamma Spectroscopy ◽  
Natural Radionuclide ◽  
Germanium Detector ◽  
Average Concentration ◽  
Radium Equivalent Activity ◽  
Lifetime Cancer Risk ◽  
Potassium 40 ◽  
Thorium 232

The normal radioactivity levels of Uranium-238, Thorium-232, and Potassium-40 were calculated for ten types of foreign and local cigarettes available on the Iraqi market using a gamma-ray spectroscopy technique employing the germanium detector system. The results of this study showed that the average specific activity for each of Uranium-238, Thorium-232 and Potassium-40 were 21.689± 4.596, 18.906 ± 4.148, and 430.094 ± 19.449 (Bq/Kg) respectively. The annual effective dose, radium equivalent activity and excess lifetime cancer risk for the studied samples were also calculated, and their rates were 11.582 μsv/y, 81.841 Bq/Kg, and 40.538 people per million per year respectively. The outcomes indicate that the rate of concentration of uranium and thorium is lower than the permissible values, whereas the average concentration of potassium was slightly higher than the permissible values. This research is important because it warns against several types of cigarettes that contain high concentrations of radionuclides, which can lead to infection cancer and then lead to the death of the person who has used it profusely. Therefore, the aim of the current research is to evaluate the radiological risks of radionuclides in tobacco cigarette smoke by evaluating their natural radionuclide concentrations.

scholarly journals Fermi-LAT and WMAP observations of the supernova remnant Puppis A

2013 ◽  
Vol 9 (S296) ◽  
pp. 295-299
Author(s):  
Marie-Hélène Grondin ◽  
John W. Hewitt ◽  
Marianne Lemoine-Goumard ◽  
Thierry Reposeur ◽  
Keyword(s):  
Supernova Remnants ◽  
Supernova Remnant ◽  
Gamma Ray ◽  
High Energy ◽  
Radio Spectrum ◽  
Wilkinson Microwave Anisotropy Probe ◽  
Large Area ◽  
X Ray ◽  
Inverse Compton Scattering ◽  
Γ Ray

AbstractThe supernova remnant (SNR) Puppis A (aka G260.4-3.4) is a middle-aged supernova remnant, which displays increasing X-ray surface brightness from West to East corresponding to an increasing density of the ambient interstellar medium at the Eastern and Northern shell. The dense IR photon field and the high ambient density around the remnant make it an ideal case to study in γ-rays. Gamma-ray studies based on three years of observations with the Large Area Telescope (LAT) aboard Fermi have revealed the high energy gamma-ray emission from SNR Puppis A. The γ-ray emission from the remnant is spatially extended, and nicely matches the radio and X-ray morphologies. Its γ-ray spectrum is well described by a simple power law with an index of ~2.1, and it is among the faintest supernova remnants yet detected at GeV energies. To constrain the relativistic electron population, seven years of Wilkinson Microwave Anisotropy Probe (WMAP) data were also analyzed, and enabled to extend the radio spectrum up to 93 GHz. The results obtained in the radio and γ-ray domains are described in detail, as well as the possible origins of the high energy γ-ray emission (Bremsstrahlung, Inverse Compton scattering by electrons or decay of neutral pions produced by proton interactions).

Effect of γ-ray irradiation on performance of LiNbO(3)-based piezoelectric vibration sensors

2021 ◽  
Author(s):  
Huifen Wei ◽  
Wenping Geng ◽  
Kaixi Bi ◽  
Tao Li ◽  
Xiangmeng Li ◽  
...  
Keyword(s):  
Gamma Ray ◽  
Extreme Environments ◽  
Theoretical Work ◽  
High Dose ◽  
Mems Devices ◽  
Micro Electro Mechanical Systems ◽  
Vibration Sensors ◽  
Irradiation Dosage ◽  
Gamma Ray Irradiation ◽  
Γ Ray

Abstract LiNbO3 (LN)-based micro-electro-mechanical systems (MEMS) vibration sensors exhibit giant prospection in extreme environments, where exist a great amount of irradiation. However, to the best of our knowledge, it is still unknown whether the irradiation affects the performance of LN-based piezoelectric MEMS sensors. Based on this consideration, it is necessary to model the irradiation environment to investigate the effect of high dosage irradiation on LN-based vibration sensors. Firstly, the theoretical work is done to study the Compton Effect on the Gamma-ray irradiation with Co-60 source. After irradiation, X-ray diffraction (XRD) characterization was performed to verify the effect of irradiation on the crystalline of LN thin film. Meanwhile, the performances of output voltages on the five MEMS devices under various dosage of irradiation are compared. As a result, a neglected shift of 0.02 degrees was observed from the XRD image only under maximum irradiation dosage of 100 Mrad(Si). Moreover, the output voltages of cantilever-beam vibration sensors decrease by 3.1%. Therefore, it is verified that the γ-ray irradiation has very little influence on the LN-based MEMS vibration sensors, which have great attraction on the materials and sensors under high-dose irradiation.

scholarly journals X-ray and Gamma-ray Radiation from the Switched-off Radiopulsars

1983 ◽  
Vol 101 ◽  
pp. 505-507
Author(s):  
A. I. Tsygan
Keyword(s):  
Neutron Stars ◽  
Magnetic Dipole ◽  
Gamma Ray ◽  
Neutral Hydrogen ◽  
Dipole Radiation ◽  
X Ray ◽  
Electron Positron ◽  
Hard Radiation ◽  
Γ Ray ◽  
Generate Electron

It is shown that pulsars that have ceased to generate electron-positron pairs (switched-off radiopulsars) may be the sources of X-ray and γ-ray radiation. The magnetic dipole radiation from these rotating neutron stars is transformed near the “light radius” into hard radiation by the plasma that is created due to ionization of interstellar neutral hydrogen.

scholarly journals Gamma-Ray Spectral Unfolding of CdZnTe-Based Detectors Using a Genetic Algorithm

Sensors ◽  
2020 ◽  
Vol 20 (24) ◽  
pp. 7316
Author(s):  
Nicola Sarzi Amadè ◽  
Manuele Bettelli ◽  
Nicola Zambelli ◽  
Silvia Zanettini ◽  
Giacomo Benassi ◽  
...  
Keyword(s):  
Genetic Algorithm ◽  
Room Temperature ◽  
Gamma Ray ◽  
Spectral Shape ◽  
Semiconductor Detectors ◽  
Arduous Task ◽  
Γ Ray ◽  
Spectral Unfolding ◽  
Single Pixel ◽  
True Energy

The analysis of γ-ray spectra can be an arduous task, especially in the case of room temperature semiconductor detectors, where several distortions and instrumental artifacts conceal the true spectral shape. We developed a genetic algorithm to perform the unfolding of γ-spectra in order to restore the true energy distribution of the incoming radiation. We successfully validated our approach on experimental spectra of four radionuclides (241Am, 57Co, 137Cs and 133Ba) acquired with two CdZnTe-based detectors with different contact geometries (single pixel and drift strip). The unfolded spectra consist of δ-like peaks in correspondence with the radiation emissions of each radioisotope.

scholarly journals Low-background, digital gamma-ray spectrometer with BEGe detector and active shield: commissioning, optimisation and software development

2019 ◽  
Vol 322 (3) ◽  
pp. 1311-1321
Author(s):  
Krzysztof Gorzkiewicz ◽  
Jerzy Wojciech Mietelski ◽  
Renata Kierepko ◽  
Kamil Brudecki
Keyword(s):  
Gamma Ray ◽  
Germanium Detector ◽  
Low Background ◽  
Gamma Ray Spectrometer ◽  
Annihilation Peak ◽  
The Mean ◽  
Plastic Scintillators ◽  
Set Up ◽  
Active Shield ◽  
Broad Energy

Abstract This paper presents results of the development process of low-background, digital gamma-rays spectrometer equipped with Broad Energy Germanium detector (CANBERRA BE5030), multi-layer passive shield and cosmic veto system that consists of five plastic scintillators (SCIONIX EJ-200). Data acquisition is performed using digitizer CAEN DT5725 with CoMPASS software. Output data analysis is carried out with purposely written and developed code VETO. On the basis of conducted tests, acquisition parameters were set up and tuned as well as time delays between all detectors were established. As a result of the configuration process, the mean background counts reduction of 64% in the whole spectrum and 65% in annihilation peak were achieved. This procedure allowed diminishing detection limits of selected isotopes 37% on average.

Sign in / Sign up

Export Citation Format

Share Document