scholarly journals Determination of in situ detection efficiency for IM-NAA of non-standard geometrical samples

2021 ◽  
Vol 9 (4) ◽  
pp. 27-33
Author(s):  
Duy Quang Nguyen ◽  
Van Cuong Trinh ◽  
Tuan Anh Tran ◽  
Van Doanh Ho ◽  
Thi Tho Nguyen ◽  
...  
Keyword(s):  
Gamma Rays ◽  
Gamma Ray ◽  
Detection Efficiency ◽  
Standard Geometry ◽  
Activation Products ◽  
Geometrical Effects ◽  
In Situ Detection ◽  
Relative Detection

The k0-based internal mono-standard (IM) method was first proposed for the concentration analysis of samples of non-standard geometry in the 2000s. The method has demonstrated several advantages such as the elimination of gamma-ray self-attenuation and geometrical effects. On the other hand, the accuracy of the method principally depends on the in situ relative detection efficiency, which requires to be obtained in each measurement. Therefore, the relative detection efficiency is always under consideration for the improvement of the analysis results. The present paper describes a simple and automatic procedure for the determination of the relative efficiency using one or more activation products emitting gamma rays over a considered range of the spectrum. The procedure can be applied for INAA and PGNAA analysis.

In situ study of the 41Ar plume released from the Ignalina NPP

Open Physics ◽  
2008 ◽  
Vol 6 (4) ◽  
Author(s):  
Rimvydas Jasiulionis ◽  
Linas Vyčinas ◽  
Andrej Rožkov
Keyword(s):  
Gamma Rays ◽  
Nuclear Power ◽  
Gamma Ray ◽  
Emission Rate ◽  
Technological Regime ◽  
In Situ Study ◽  
In Situ Method ◽  
Operating Reactor

AbstractThe 41Ar gamma ray radiation was registered using the in situ method in the vicinity of the Ignalina nuclear power plant (NPP). The sum of gamma rays, that are reaching the HPGe detector, situated along the wind direction, from a number of plume segments and which are registered in the energy range of about 1.29 MeV, is calculated. An independent technological regime of the operating reactor method of the determination of the 41Ar emission rate from NPP stack is introduced.

THE INTERPLAY OF PROMPT AND AFTERGLOW EMISSION IN GRB 060418

2008 ◽  
Vol 17 (09) ◽  
pp. 1343-1349 ◽  
Author(s):  
S. D. VERGANI ◽  
D. MALESANI ◽  
E. MOLINARI
Keyword(s):  
Gamma Rays ◽  
Spectral Properties ◽  
Gamma Ray ◽  
Early Time ◽  
Lorentz Factor ◽  
X Ray ◽  
Central Engine ◽  
Low Energies ◽  
Prompt Emission

We present observations of the early afterglow emission of GRB 060418. Thanks to the simultaneous coverage at optical, X-ray and gamma-ray wavelengths, we can detect and separate the external shock emission (visible in the optical and late X-ray data) and the central engine activity (early X and gamma rays). The two components are clearly distinguished based on temporal and spectral properties. The detection of the afterglow onset (in the optical) allows the determination of the fundamental fireball properties, namely its bulk Lorentz factor and total energy. The early time X-ray flare closely resembles the prompt emission gamma-ray pulses in its temporal profile, being wider at low energies and showing lags between the hard and soft bands. This provides a strong suggestion that X-ray flares are a continuation of the prompt emission.

scholarly journals Real Time In-situ Detection System Research for Methane in Offshore Shallow Gas based on Thin Film Interface

2018 ◽  
Vol 232 ◽  
pp. 04053
Author(s):  
Cheng-xing Miao ◽  
Qing Li ◽  
Sheng-yao Jia
Keyword(s):  
Real Time ◽  
Detection Efficiency ◽  
Detection System ◽  
Detection Methods ◽  
Shallow Gas ◽  
Micro Gas Sensor ◽  
Detection Probe ◽  
On Line ◽  
In Situ Detection

In order to get ridded of the non real-time detection methods of artificial site sampled and laboratory instrument analyzed in the field of methane detection in the offshore shallow gas, real-time in-situ detection system for methane in offshore shallow gas was designed by the film interface.The methane in the offshore shallow gas through the gas-liquid separation membrane of polymer permeation into the system internal detection probe, analog infrared micro gas sensor sensed the methane concentration and the corresponded output value, data acquisition and communication node fitted into standard gas concentration.Based on the experimental data compared with the traditional detection method, and further analyzed the causes of error produced by the case experiment. The application results show that the system can achieve a single borehole layout, long-term on-line in-situ on-line detection, and improve the detection efficiency and the timeliness of the detection data.

In situ gamma-ray spectrometry in forests: determination of kerma rate in air from 137Cs

2002 ◽  
Vol 61 (1) ◽  
pp. 75-89 ◽  
Author(s):  
F. Gering ◽  
P. Kiefer ◽  
S. Fesenko ◽  
G. Voigt
Keyword(s):  
Gamma Ray ◽  
Gamma Ray Spectrometry

scholarly journals Determination of Gamma-Ray Shielding Parameters for Concretes and Dosimeters Using MCNPX

2020 ◽  
Vol 8 (1) ◽  
pp. 73-79
Author(s):  
V. P. Singh ◽  
Huseyin Ozan Tekin
Keyword(s):  
Large Scale ◽  
Gamma Ray ◽  
Simulation Method ◽  
Radiological Protection ◽  
Simulation Tool ◽  
Alternative Method ◽  
Standard Geometry ◽  
Good Agreement

Gamma-ray shielding parameter for some concretes and dosimeters having large scale applications in radiological protection are presented using MCNPX (version 2.4.0) at different energies. The MCNPX results are compared with experimental, MCNP and XCOM data, and good agreement is being noted. Present study indicates that MCNPX simulation method is suitable and reliable simulation tool to be used as an alternative method for the investigation of gamma-ray interaction. The present geometry can be used as standard geometry for MCNPX simulation for low- as well as high-Z materials.

scholarly journals Revealing x-ray and gamma ray temporal and spectral similarities in the GRB 190829A afterglow

Science ◽  
2021 ◽  
Vol 372 (6546) ◽  
pp. 1081-1085
Author(s):  
◽  
H. Abdalla ◽  
F. Aharonian ◽  
F. Ait Benkhali ◽  
E. O. Angüner ◽  
...  
Keyword(s):  
Gamma Rays ◽  
Gamma Ray ◽  
High Energy ◽  
X Ray ◽  
Photon Index ◽  
Very High Energy ◽  
Stereoscopic System ◽  
Very High ◽  
Intrinsic Energy

Gamma-ray bursts (GRBs), which are bright flashes of gamma rays from extragalactic sources followed by fading afterglow emission, are associated with stellar core collapse events. We report the detection of very-high-energy (VHE) gamma rays from the afterglow of GRB 190829A, between 4 and 56 hours after the trigger, using the High Energy Stereoscopic System (H.E.S.S.). The low luminosity and redshift of GRB 190829A reduce both internal and external absorption, allowing determination of its intrinsic energy spectrum. Between energies of 0.18 and 3.3 tera–electron volts, this spectrum is described by a power law with photon index of 2.07 ± 0.09, similar to the x-ray spectrum. The x-ray and VHE gamma-ray light curves also show similar decay profiles. These similar characteristics in the x-ray and gamma-ray bands challenge GRB afterglow emission scenarios.

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