scholarly journals Characterization and Monte Carlo simulations for a CLYC detector

2018 ◽  
Vol 48 ◽  
pp. 1860115
Author(s):  
Alessandro Borella ◽  
Eric Boogers ◽  
Riccardo Rossa ◽  
Peter Schillebeeckx
Keyword(s):  
Monte Carlo ◽  
Gamma Ray ◽  
Detection System ◽  
Nuclear Material ◽  
Point Sources ◽  
Pulse Shape Discrimination ◽  
Monte Carlo Code ◽  
Nuclear Security ◽  
Collaborative Agreement ◽  
Personal Dosimetry

The CLYC (Cs[Formula: see text]LiYCl[Formula: see text]:Ce) detector is a scintillator detector sensitive to both neutron and gamma radiation and capable of separating the two types of radiation by pulse-shape discrimination. This feature is interesting as pertains to the development of non-destructive assays for the safeguard of nuclear material, nuclear security, and fast-neutron personal dosimetry. A [Formula: see text] CLYC detector highly enriched with [Formula: see text]Li was purchased and tested with analog and digital electronics. In this work, we report on the characterization of the detector in terms of linearity, energy resolution, and full-energy efficiency for gamma rays. This characterization was achieved by measurements with calibrated gamma-ray point-sources with an analog measuring chain, in a well-defined, reproducible geometry. The experimental data were also used to validate a model of the detection system that was developed with the Monte Carlo code MCNP-CP. This work is part of a collaborative agreement between SCK•CEN and JRC-Geel.

scholarly journals Thyroid cell irradiation by radioiodines: a new Monte Carlo electron track-structure code

2007 ◽  
Vol 50 (spe) ◽  
pp. 135-144 ◽  
Author(s):  
Christophe Champion ◽  
Mouhamad Elbast ◽  
Ting-Di Wu ◽  
Nicole Colas-Linhart
Keyword(s):  
Monte Carlo ◽  
Cellular Level ◽  
Biological Data ◽  
Point Sources ◽  
Thyroid Cell ◽  
Track Structure ◽  
Monte Carlo Code ◽  
Beta Particles ◽  
Low Energies ◽  
Rat Thyroid

The most significant impact of the Chernobyl accident is the increased incidence of thyroid cancer among children who were exposed to short-lived radioiodines and 131-iodine. In order to accurately estimate the radiation dose provided by these radioiodines, it is necessary to know where iodine is incorporated. To do that, the distribution at the cellular level of newly organified iodine in the immature rat thyroid was performed using secondary ion mass microscopy (NanoSIMS50). Actual dosimetric models take only into account the averaged energy and range of beta particles of the radio-elements and may, therefore, imperfectly describe the real distribution of dose deposit at the microscopic level around the point sources. Our approach is radically different since based on a track-structure Monte Carlo code allowing following-up of electrons down to low energies (~ 10eV) what permits a nanometric description of the irradiation physics. The numerical simulations were then performed by modelling the complete disintegrations of the short-lived iodine isotopes as well as of 131I in new born rat thyroids in order to take into account accurate histological and biological data for the thyroid gland.

scholarly journals Assessment of a polymeric composite as a radiation attenuator and a restoration mortar for cracking in biological shields

2020 ◽  
Vol 21 (4) ◽  
pp. 361-368
Author(s):  
A.T. Gheith ◽  
◽  
M.A. El-Sarraf ◽  
I.E. Hasan ◽  
N.L. Helal ◽  
...  
Keyword(s):  
Thermal Neutron ◽  
Cross Sections ◽  
Gamma Ray ◽  
Detection System ◽  
Polymeric Composite ◽  
Pulse Shape Discrimination ◽  
Attenuation Relations ◽  
Attenuation Coefficients ◽  
Effective Removal ◽  
Collimated Beam

This work is dedicated to figuring out robust epoxy/magnetite/boron carbide (EP/Mag/B4C) composite for radiation attenuation at multiple applications related to nuclear installations, as well as restoration mortar for cracking developed in concrete biological shields. The mechanical properties (flexural, compressive, and impact strengths) and the physical properties (water absorption, porosity, and dry bulk density), each, have been performed to label the composite integrity for practical application. In practice, attenuation properties have been performed by using a collimated beam emitted from spontaneous fission 252Cf (100 μg) neutron source and neutron gamma spectrometer with stilbene scintillator. The pulse shape discrimination technique which would come of the zero cross over method was used to measure the fast neutron and gamma-ray spectra. Thermal neutron fluxes have been measured by using the thermal neutron detection system and the BF-3 detector. The attenuation parameters: precisely, macroscopic effective removal cross-sections ΣR (cm-1), macroscopic cross-sections Σ (cm-1), and total attenuation coefficients μ (cm-1) of fast and thermal neutrons and total gamma-rays respectively were evaluated using the attenuation relations. Also, the MCNP5 code and MERCSF-N program have been used to compute the parameters theoretically. When applicable, measured and calculated results were compared, and it tells us a comprehensive agreement.

scholarly journals A new methodology for determination of water of crystallization for uranyl nitrate samples using scanning electron microscope, energy dispersive X-ray, and MCPN-5

2019 ◽  
Vol 34 (4) ◽  
pp. 368-374
Author(s):  
Sameh Shaban ◽  
Mohamed Hazzaa ◽  
Rasha El-Tayebany
Keyword(s):  
Monte Carlo ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Uranyl Nitrate ◽  
Nuclear Material ◽  
Energy Dispersive ◽  
Monte Carlo Code ◽  
Suggested Approach ◽  
X Ray ◽  
Scanning Electron

The scanning electron microscope and its attached X-ray unit are valid tools for conducting surveys to determine whether or not the studied samples contain nuclear material. To verify their structure, ten solid uranyl nitrate specimens with various enrichment values (0.1 % to 1 %) were analyzed. The used samples have different numbers of hydrated water molecules; consequently, the properties of these materials in analytical chemistry and computational methods are not the same. Scanning electron microscope and energy dispersive X-ray are used in this work to visualize and analyze the sample of hexahydrate uranyl nitrate (natural 0.72 %). The specimen has been screened under optimal microscopy circumstances. In spite of the reliability of these tools, they are not accurate, particularly when carrying out complete qualitative and quantitative analysis. With the aid of the Monte Carlo code (MCNP-5), the approach presented here can resolve the limitations that tackle the microscope and X-ray testing. The suggested approach relates to the Monte Carlo calculations and X-ray elemental analysis. This relationship depends on the chemical composition of the material and was developed like software. The concentration and count rate calculation software has been established to determine the water of crystallization for uranyl nitrate samples.

Neutron Radiography System Collimator Design via Monte Carlo Calculation

2010 ◽  
Author(s):  
Hamid Jafari ◽  
Majid Shahriari
Keyword(s):  
Monte Carlo ◽  
Neutron Flux ◽  
Neutron Source ◽  
Gamma Ray ◽  
Neutron Radiography ◽  
Image Plane ◽  
Monte Carlo Code ◽  
Radiography System ◽  
Neutron Filter ◽  
Non Destructive

Neutron radiography uses the unique interaction probabilities of neutrons to create images of materials. This imaging technique is non-destructive. MCNP Monte Carlo Code has been used to design an optimized neutron radiography system that utilizes 241Am-Be neutron source. Many different arrangements have been simulated to obtain a neutron flux with higher amplitude and more uniform distribution in the collimator outlet, next to image plane. In the final arrangement the specifications of neutron filter, Gamma-ray shield and beam collimator has been determined. Simulations has been Carried out for a 5Ci 241Am-Be neutron source. In this case 43.8 n/cm2s thermal neutron flux has been achieved at a distance of 35cm from neutron source.

Validation of gamma-ray true coincidence summing effects modeled by the Monte Carlo code MCNP-CP

2008 ◽  
Vol 278 (2) ◽  
pp. 359-363 ◽  
Author(s):  
H. Zhu ◽  
R. Venkataraman ◽  
N. Menaa ◽  
W. Mueller ◽  
S. Croft ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Gamma Ray ◽  
Monte Carlo Code ◽  
True Coincidence ◽  
True Coincidence Summing ◽  
Coincidence Summing

scholarly journals Radiation portal monitors response to gamma radiation and to the detection capability of Orphan radioactive sources: Contribution of the Strass project

2020 ◽  
Vol 35 (3) ◽  
pp. 244-252
Author(s):  
Alexandros Clouvas ◽  
Fokion Leontaris ◽  
Stelios Xanthos
Keyword(s):  
Monte Carlo ◽  
Gamma Radiation ◽  
Gamma Ray ◽  
Spectral Response ◽  
Energy Shift ◽  
Point Sources ◽  
Photo Multiplier Tube ◽  
Radioactive Sources ◽  
Response Testing ◽  
Compton Edge

Radiation portal monitors are commonly used to detect and intercept unauthorized movement of nuclear and other radioactive materials at country borders. A total of twelve double-pillar portal monitors are present at the Greek-North Macedonian border, each containing two polystyrene scintillating detectors per pillar. Spatial and spectral response testing of the scintillating detectors to gamma radiation was performed by using different radioactive sources and comparing the measurement results with Monte Carlo simulations. A good agreement of the experimentally deduced activities of different point sources, needed for alarm triggering of the radiation portal monitors with Monte Carlo calculated values, was observed. Spectral results show no photopeaks in the spectra due to low resolution of these detectors. The broad peaks observed in the spectra correspond to the Compton edge. Measured spectra with a 137Cs source placed directly on the scintillating detector, at several positions away from the photo multiplier tube, show an energy shift of the Compton edge towards lower energies, as the source is moving away from the photo multiplier tube. The energy shift is due to light transfer mechanisms within the scintillator volume and therefore, it is only observed in optical simulations and not in gamma-ray particle simulations.

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