Polymers in Concrete – The Shielding against Neutron Radiation

2015 ◽  
Vol 1129 ◽  
pp. 131-138 ◽  
Author(s):  
Tomasz Piotrowski ◽  
Dariusz B. Tefelski ◽  
Michał Mazgaj ◽  
Janusz Skubalski ◽  
Andrzej Żak ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Experimental Studies ◽  
Neutron Radiation ◽  
High Energy ◽  
Fast Neutrons ◽  
Final Conclusion ◽  
Concrete Technology ◽  
Neutron Shielding ◽  
Neutron Attenuation

Concrete has been used as a shield against high-energy photons (gamma) and neutrons since the beginning of use of nuclear reaction in energy, medicine and research. State of knowledge in shielding concrete technology is that while in case of protection against gamma radiation an increase in density caused by change of aggregate type for heavy-weight one is usually an efficient solution, the protection against neutrons is more complex. It is due to the differences in interactions of neutrons with the matter, depending on their kinetic energy and cross-sections for different reactions of the component atoms of the cement paste and the aggregate. The paper presents the results of the project NGS-Concrete - New-Generation Shielding Concrete. The aim is to design the composition of concrete against ionizing radiation, achieved by the use of experiment based on multi-criteria optimization of materials supported by the Monte Carlo simulations. Better concrete is the one that absorbs more thermal neutrons and slows down more fast neutrons at the same time. In the paper both results of Monte Carlo simulations and experimental studies on ordinary and heavyweight concrete containing epoxy polymer additive are presented. Close values of thermal neutron attenuation coefficients proved good accordance between simulation and experiment. The final conclusion is that epoxy resin is an efficient additive for neutron shielding concretes improving its ability to protect mainly against low energy neutrons. In experimental measurement there has not been observed an improvement of fast neutron attenuation due to increase of hydrogen atom content introduced with epoxy.

MCNPX Monte Carlo simulations of particle transport in SiC semiconductor detectors of fast neutrons

2014 ◽  
Vol 9 (05) ◽  
pp. C05016-C05016 ◽  
Author(s):  
K Sedlačková ◽  
B Zat'ko ◽  
A Šagátová ◽  
M Pavlovič ◽  
V Nečas ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Particle Transport ◽  
Fast Neutrons ◽  
Semiconductor Detectors

In-Situ Measurement of Artificial Nuclides in Seabed Sediments Based on Monte Carlo Simulations and an Underwater HPGe Detector

2019 ◽  
Vol 53 (3) ◽  
pp. 16-22
Author(s):  
Jinzhao Zhang ◽  
Hongzhi Li ◽  
Xianguo Tuo
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Energy Resolution ◽  
Hpge Detector ◽  
High Energy ◽  
In Situ Measurement ◽  
Energy Calibration ◽  
High Energy Resolution ◽  
Seabed Sediments

AbstractIn-situ measurement of marine sediment radioactivity does not destroy the stratification of radionuclides in the sediment. We develop a novel seabed sediment radioactive measurement technique using a High Purity Germanium (HPGe) detector. The overall measurement system is designed, and the detector energy calibration is performed. The efficiency is calculated based on Monte Carlo simulations using the MCNP5 code. We compared the efficiency and energy resolution with the NaI(Tl) detection through experiments. NaI(Tl) detection is incapable of identifying the 137Cs artificial nuclides in seabed sediments due to the energy resolution limit. Hence, underwater HPGe detection is utilized due to its high energy resolution, which enables the detection of artificial nuclides 137Cs. The proposed method is of great significance in evaluating marine radioactive pollution.

Energy spectrum from single TGFs detected by ASIM

2020 ◽  
Author(s):  
Anders Lindanger ◽  
Martino Marisaldi ◽  
Nikolai Østgaard ◽  
Andrey Mezentsev ◽  
Torstein Neubert ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Spectral Analysis ◽  
Energy Spectrum ◽  
Monte Carlo Simulations ◽  
Energy Range ◽  
Gamma Ray ◽  
High Energy ◽  
Energy Calibration ◽  
Energy Detector ◽  
Instrumental Effects

<p>Terrestrial Gamma-ray Flashes (TGFs) are sub milliseconds bursts of high energy photons associated with lightning flashes in thunderstorms. The Atmosphere-Space Interactions Monitor (ASIM), launched in April 2018, is the first space mission specifically designed to detect TGFs. We will mainly focus on data from the High Energy Detector (HED) which is sensitive to photons with energies from 300 keV to > 30 MeV, and include data from the Low Energy Detector (LED) sensitive in 50 keV to 370 keV energy range. Both HED and LED are part of the Modular X- and Gamma-ray Sensor (MXGS) of ASIM.<br><br>The energy spectrum of TGFs, together with Monte Carlo simulations, can provide information on the production altitude and beaming geometry of TGFs. Constraints have already been set on the production altitude and beaming geometry using other spacecraft and radio measurements. Some of these studies are based on cumulative spectra of a large number of TGFs (e.g. [1]), which smooth out individual variability. The spectral analysis of individual TGFs has been carried out up to now for Fermi TGFs only, showing spectral diversity [2]. Crucial key factors for individual TGF spectral analysis are a large number of counts, an energy range extended to several tens of MeV, a good energy calibration as well as knowledge and control of any instrumental effects affecting the measurements.</p><p>We strive to put stricter constraints on the production altitude and beaming geometry, by comparing Monte Carlo simulations to energy spectra from single ASIM TGFs. We will present the dataset and method, including the correction for instrumental effects, and preliminary results on individual TGFs.</p><p>Thanks to ASIM’s large effective area and low orbital altitude, single TGFs detected by ASIM have much more count statistics than observations from other spacecrafts capable of detecting TGFs. ASIM has detected over 550 TGFs up to date (January 2020), and ~115 have more than 100 counts. This allows for a large sample for individual spectral analysis.</p><p>References:</p><ol><li>Dwyer, J. R., and D. M. Smith (2005), A comparison between Monte Carlo simulations of runaway breakdown and terrestrial gamma-ray flash observations, Geophys. Res. Lett., 32, L22804, doi:10.1029/2005GL023848.</li> <li>Mailyan et al. (2016), The spectroscopy of individual terrestrial gamma-ray flashes: Constraining the source properties, J. Geophys. Res. Space Physics, 121, 11,346–11,363, doi:10.1002/2016JA022702.</li> </ol>

scholarly journals Electron Irradiation-Induced Mechanical Property Changes in Reactor Pressure Vessel Alloys

1995 ◽  
Vol 398 ◽  
Author(s):  
Dale E. Alexander ◽  
G.R. Odette ◽  
G.E. Lucas ◽  
L.E. Rehn
Keyword(s):  
Mechanical Property ◽  
Neutron Irradiation ◽  
Experimental Studies ◽  
High Energy ◽  
Fast Neutrons ◽  
Apparent Effect ◽  
Alloy Chemistry ◽  
High Energy Electrons ◽  
Property Changes ◽  
Reactor Pressure

ABSTRACTHigh-energy electrons were used to study tensile property changes in simple Fe-Cu and Fe-Cu-Mn alloys irradiated at 288°C. A comparison was made with neutron irradiation data on the same alloys. An apparent effect of alloy chemistry was observed in which the presence of Mn affected embrittlement differently for electron and neutron irradiation. Comparison of previous experimental studies with the present experimental results indicates that electrons may be more efficient than fast neutrons at producing embrittlement.

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