scholarly journals Improving the performance of 241Am-Be for PGNAA applications using a proper shielding for neutron source and the NaI detector

2010 ◽  
Vol 25 (3) ◽  
pp. 205-211 ◽  
Author(s):  
Hamed Panjeh ◽  
Hashem Hakimabad ◽  
Lalle Motavalli
Keyword(s):  
Gamma Rays ◽  
Energy Region ◽  
Gamma Ray ◽  
Region Of Interest ◽  
High Rate ◽  
Prompt Gamma ◽  
Peak Resolution ◽  
Set Up ◽  
Gamma Ray Detector

The gamma ray spectrum resolution from a 241Am-Be source-based prompt gamma ray activation analysis set-up has been observed to increase in the energy region of interest with enclosing the NaI detector in a proper neutron and gamma ray shield. We have investigated the tact that the peak resolution of prompt gamma rays in the region of interest from the set-up depends on the source activity to the great extent, size and kind of the detector and the geometry of the detector shield. In order to see the role of a detector shield, five kinds of the detector shield were used and finally the proper kind was introduced. Since the detector shield has an important contribution in the reduction of the undesirable and high rate gamma rays coming to the gamma ray detector, a good design of a proper shield enables the elimination of the unwanted events, such as a pulse pile-up. By improving the shielding design, discrete and distinguishable photoelectric peaks in the energy region of interest have been observed in the spectrum of prompt gamma rays.

scholarly journals Optical Afterglows as Probes for the Central Engine and Fireball of Gamma-Ray Bursts

2012 ◽  
Vol 8 (S290) ◽  
pp. 263-264
Author(s):  
Liang Li ◽  
En-Wei Liang ◽  
He Gao ◽  
Bing Zhang
Keyword(s):  
Statistical Analysis ◽  
Gamma Rays ◽  
Density Profile ◽  
Gamma Ray ◽  
Ambient Medium ◽  
Gamma Ray Bursts ◽  
Prompt Gamma ◽  
Medium Density ◽  
Central Engine ◽  
Prompt Emission

AbstractWell-sampled optical lightcurves of 146 gamma-ray bursts (GRBs) are compiled from literature. We identify possible emission components based on our empirical fits and present statistical analysis for these components. We find that the flares are related to prompt emission, suggesting that they could have the same origin in different episodes. The shallow decay segment is not correlated with prompt gamma-rays. It likely signals a long-lasting injected wind from GRB central engines. Early after onset peak is closely related with prompt emission. The ambient medium density profile is likely n ∝ r−1. No correlation between the late re-brightening bump and prompt gamma-rays or the onset bump is found. They may be from another jet component.

Measurement Mass Attenuation Coefficient of Palmitic Acid by Using Sources of Gamma Ray

2021 ◽  
Vol 19 (6) ◽  
pp. 107-114
Author(s):  
Mohammed Yahya Hadi ◽  
Ali Hussein F. Alnasraui ◽  
Ali Adil Turki Aldalawi
Keyword(s):  
Attenuation Coefficient ◽  
Gamma Rays ◽  
Gamma Ray ◽  
Radiation Force ◽  
Mass Attenuation Coefficient ◽  
Fluorescence Detector ◽  
Effective Electron ◽  
Effective Atomic Numbers ◽  
Gamma Ray Detector ◽  
Mass Attenuation

The purpose of this paper is to determine the mass attenuation coefficient (μ/ρ), of a sample. In this work used (C16H32O2) fatty acid, exposed to gamma rays (γ), emitted from various sources 57Co, 133Ba, 22Na, 137Cs, 54Mn, and sCo with energies from 0.122 to 1.330 MeV. It exposes the compound to gamma rays and discloses the radiation force that passes through the sample, the rest of the gamma radiation attenuated. A NaI fluorescence detector (Tl) with an accuracy of 8.2% (at 662 kV) was used for the gamma ray detector beam. An advantage of using (μ/ρ) coefficient data can be obtained effective atomic numbers, atomic cross-section and effective electron densities.

scholarly journals INTERNAL ENERGY DISSIPATION OF GAMMA-RAY BURSTS OBSERVED WITHSWIFT: PRECURSORS, PROMPT GAMMA-RAYS, EXTENDED EMISSION, AND LATE X-RAY FLARES

2014 ◽  
Vol 789 (2) ◽  
pp. 145 ◽  
Author(s):  
You-Dong Hu ◽  
En-Wei Liang ◽  
Shao-Qiang Xi ◽  
Fang-Kun Peng ◽  
Rui-Jing Lu ◽  
...  
Keyword(s):  
Energy Dissipation ◽  
Internal Energy ◽  
Gamma Rays ◽  
Gamma Ray ◽  
Gamma Ray Bursts ◽  
Prompt Gamma ◽  
X Ray ◽  
Extended Emission

WE-D-BRF-03: Proton Beam Range Verification with a Single Prompt Gamma-Ray Detector

2014 ◽  
Vol 41 (6Part29) ◽  
pp. 495-495
Author(s):  
J Verburg ◽  
M Testa ◽  
E Cascio ◽  
T Bortfeld ◽  
H Lu ◽  
...  
Keyword(s):  
Proton Beam ◽  
Gamma Ray ◽  
Prompt Gamma ◽  
Gamma Ray Detector ◽  
Beam Range ◽  
Range Verification

scholarly journals Absolute Calibration of a Prompt Gamma-Ray Detector for Intense Bursts of Protons

1981 ◽  
Vol 9 (1) ◽  
pp. 24-29 ◽  
Author(s):  
F. C. Young ◽  
W. F. Oliphant ◽  
S. J. Stephanakis ◽  
A. R. Knudson
Keyword(s):  
Gamma Ray ◽  
Absolute Calibration ◽  
Prompt Gamma ◽  
Gamma Ray Detector

scholarly journals Shielding Analysis of Metal Hydride-based Materials for Both Neutron and Gamma Rays Using Monte Carlo Simulation

2021 ◽  
Vol 59 (12) ◽  
pp. 921-925
Author(s):  
Jeongkwon Kwak ◽  
Boravy Muth ◽  
Hyeon-Woo Yang ◽  
Chang Je Park ◽  
Woo Seung Kang ◽  
...  
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Gamma Rays ◽  
Multilayer Structure ◽  
Gamma Ray ◽  
Accurate Method ◽  
Multilayered Structure ◽  
Manufacturing Cost ◽  
Human Poisoning ◽  
Set Up

Radiation causes damage to the human body, the environment, and electronic equipment. Shielding against neutron and gamma rays is particularly difficult because of their strong ability to penetrate materials. Conventional gamma ray shields are typically made of materials containing Pb. However, they pose problems in that Pb is a heavy metal, and human poisoning and/or pollution can result from the manufacturing, use, and disposal of these materials. In addition, neutron rays are shielded by materials rich in H2 or concrete. In the case of the latter, the manufacturing cost is high. Thus, it is necessary to develop a new multilayer structure that can shield against both neutron and gamma rays. We set up a simulation model of a multilayered structure consisting of metal hydrides and heavy metals, and then evaluated the simulations using Monte Carlo N-Particle Transport Code. Monte Carlo simulation is an accurate method for simulating the interaction between radiation and materials, and can be applied to the transport of radiation particles to predict values such as flux, energy spectrum, and energy deposition. The results of the study indicated the multilayer structure of ZrH2, U, and W could shield both neutron and gamma rays, thus showing potential as a new shielding material to replace Pb and concrete.

ADRON instrument for future missions to Moon and Mars: active neutron and gamma-ray spectroscopy

2021 ◽  
Author(s):  
Maxim Mokrousov ◽  
Dmitriy Golovin ◽  
Igor Mitrofanov ◽  
Alexander Kozyrev ◽  
Maxim Litvak ◽  
...  
Keyword(s):  
Gamma Rays ◽  
Neutron Generator ◽  
Gamma Ray ◽  
Pulse Neutron ◽  
Good Time ◽  
Pulse Emission ◽  
Epithermal Neutrons ◽  
Mass Fractions ◽  
Detector Block ◽  
Gamma Ray Detector

<p>The series of ADRON instruments are developed in Russian Space Research Institute (IKI) for Russian Luna-25, Luna-27 and Roscosmos-ESA ExoMars-2022 landers. The main goal of this experiment is studying of elemental composition of planetary sub-surface down to 1 m. Using pulsing neutron generator and observing albedo after-pulse neutron and gamma-ray emission from the soil, one can detect layering stratification of hydrogen and mass fractions of other elements.</p><p>Both instruments consist of two blocks: pulsing neutron generator (PNG) with 14 MeV neutron pulse duration around 1 microsecond, and detector block with neutrons and gamma-ray detectors based on <sup>3</sup>He counters and CeBr<sub>3</sub> (LaBr3) scintillator, respectively. <sup>3</sup>He counters allow to detect thermal and epithermal neutrons, which are the most sensitive to hydrogen in underlying soil, and gamma-ray detector allows to detect nuclear lines at the energy range from 200 keV up to 10 MeV. Readout and digital electronics is designed to minimize the dead-time of signal processing. It allows to accumulate the after-pulse profiles of emission of neutrons and gamma-rays with very good time (from 2 microsecond) and spectral resolutions (about 4 % for 662 keV).</p><p>The results of laboratory measurements and numerical simulations for ADRON units will be presented for post-pulse emission of neutrons and gamma rays from the planetary soil with different water content, elementary composition and layering structure.</p><p> </p>

Determination of mixing ratios for some cascades corresponding to 109Ag

1977 ◽  
Vol 55 (2) ◽  
pp. 175-179 ◽  
Author(s):  
H. E. Bosch ◽  
V. M. Silbergleit ◽  
M. Davidson ◽  
J. Davidson
Keyword(s):  
Gamma Rays ◽  
Gamma Ray ◽  
Angular Correlations ◽  
Mixing Ratios ◽  
Multichannel Analyzer ◽  
Level 3 ◽  
Gamma Ray Detector

An investigation of the gamma–gamma ray angular correlations following the decay of 109Pd was made by using a Ge(Li) semiconductor counter and NaI(Tl) gamma-ray detector. Coincidences measurements at six different angles were made between the 311 keV gamma ray (gated in the movable counter) and 390, 413, 424, 551, and 558 keV gamma rays (displayed in a multichannel analyzer (MCA)). Chance coincidences as well as coincidence background were taken into account. The following spins and mixing ratios were determined: 701 keV level 3/2, δ(390) = 0.19 ± 0.06; 724 keV level 3/2, δ(413) = 0.18 ± 0.05; 735 keV level 5/2, δ(424) = −0.27 ± 0.03; 862 keV level 5/2, δ(551) = −0.28 ± 0.04; 869 keV level 5/2, δ(558) = −0.26 ± 0.05. The result indicates that the anisotropies are consistent with mixing ratios less than 28% in all cases.

scholarly journals A Further Study of the Role of Copper in Regard to the Antimutagenic Action of Sodium Copper Chlorophyllin (SCC) in Somatic Cells of Drosophila melanogaster

2013 ◽  
Vol 8 ◽  
pp. BMI.S11081 ◽  
Author(s):  
Emilio Pimentel ◽  
Martha P. Cruces ◽  
Stanley Zimmering
Keyword(s):  
Drosophila Melanogaster ◽  
Gamma Rays ◽  
Copper Content ◽  
Gamma Ray ◽  
Somatic Cells ◽  
Food Supplement ◽  
Genetic Damage ◽  
Sodium Copper Chlorophyllin ◽  
Antimutagenic Action

Previous findings suggest that copper plays a crucial role in the antimutagenic effect of sodium copper chlorophyllin (SCC). The objective of the current research was to compare the antimutagenic effects of two SCC compounds with different amounts of copper (3.7% and 5.4%, respectively) on the genetic damage induced by gamma rays in somatic cells of Drosophila. Data indicate that an increase in copper content of 31.5% in SCC-5.4 resulted in a greater inhibition of gamma ray genetic damage of 49% whereas only a 2% inhibition with SCC-3.7 occurred. Of greater interest is the association of SCC with a variety of uses in humans, such as a chemo preventive agent and food supplement. A greater attention to the concentration of copper in the SCC product in use should be required.

Experimental set-up for the measurement of prompt gamma rays resulting from interactions of 14.5 MeV neutrons

1974 ◽  
Vol 36 (1) ◽  
pp. 25-32
Author(s):  
T. Sztaricskai ◽  
E. Barutcugil ◽  
T. Scharbert ◽  
G. Pető
Keyword(s):  
Gamma Rays ◽  
Prompt Gamma ◽  
Set Up
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