scholarly journals Cross-Verification of Monte Carlo Codes Geant4 and MCNP6 for Muon Tomography

2021 ◽  
Vol 21 (2) ◽  
pp. 49-60
Author(s):  
C. V. Hrytsiuk ◽  
◽  
А. M. Bozhuk ◽  
А. V. Nosovskyi ◽  
V. І. Gulik ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Spent Nuclear Fuel ◽  
Nuclear Data ◽  
High Energy ◽  
Intermediate Energy ◽  
Low Energy ◽  
Physical Models ◽  
Heavy Nuclei ◽  
Muon Tomography ◽  
Significant Difference

Muon tomography is a promising detection technology that uses natural radiation, the muons of cosmic rays. In the last decade, a significant number of scientific papers have appeared that investigate the possibility of using muon tomography in various fields of science and technology. Especially remarkable is the considerable potential of this technology for detecting the illegal transport of radioactive materials and for no-invasive testing of the integrity of spent nuclear fuel in dry storage facilities for such fuel. For the implementation of muon tomography technology, the process of preliminary modeling of the experimental detector facility is important, which also requires verification of the obtained calculation results. For this purpose, the well-known Monte Carlo codes MCNP and Geant4 are mainly used. This results of the first cross-verification studies of MCNP6 and Geant4 codes are demonstrated in the paper. The study was performed on simple models for different materials and for different energies of the muons bombarding the research object. The recommended QGSP_BERT physics library was used in the Geant4 code. In the MCNP6 code, the recommended settings for cosmic particle simulations were used. The calculations showed that for low-energy muons, both codes give results that agree well with each other. This can be explained by the fact that similar libraries of evaluated nuclear data are used in the low-energy range. Regarding the muons of intermediate energies, there is a significant difference between the two codes, which may indicate differences in physical models. The modeling of high-energy muon transfer has better agreement between MCNP6 and Geant4 codes than for intermediate-energy muons, but significant differences are still observed for heavy nuclei.

scholarly journals How Does Frailty Factor Into Mortality Risk Assessment of a Middle-Aged and Geriatric Trauma Population?

2017 ◽  
Vol 8 (4) ◽  
pp. 225-230 ◽  
Author(s):  
Sanjit R. Konda ◽  
Ariana Lott ◽  
Hesham Saleh ◽  
Sebastian Schubl ◽  
Jeffrey Chan ◽  
...  
Keyword(s):  
Mortality Risk ◽  
Functional Independence ◽  
High Energy ◽  
Low Energy ◽  
Geriatric Trauma ◽  
Inpatient Mortality ◽  
Middle Aged ◽  
Trauma Population ◽  
Increased Risk ◽  
Significant Difference

Introduction: Frailty in elderly trauma populations has been correlated with an increased risk of morbidity and mortality. The Score for Trauma Triage in the Geriatric and Middle-Aged (STTGMA) is a validated mortality risk score that evaluates 4 major physiologic criteria: age, comorbidities, vital signs, and anatomic injuries. The aim of this study was to investigate whether the addition of additional frailty variables to the STTGMA tool would improve risk stratification of a middle-aged and elderly trauma population. Methods: A total of 1486 patients aged 55 years and older who met the American College of Surgeons Tier 1 to 3 criteria and/or who had orthopedic or neurosurgical traumatic consultations in the emergency department between September 2014 and September 2016 were included. The STTGMAORIGINAL and STTGMAFRAILTY scores were calculated. Additional “frailty variables” included preinjury assistive device use (disability), independent ambulatory status (functional independence), and albumin level (nutrition). The ability of the STTGMAORIGINAL and the STTGMAFRAILTY models to predict inpatient mortality was compared using area under the receiver operating characteristic curves (AUROCs). Results: There were 23 high-energy inpatient mortalities (4.7%) and 20 low-energy inpatient mortalities (2.0%). When the STTGMAORIGINAL model was used, the AUROC in the high-energy and low-energy cohorts was 0.926 and 0.896, respectively. The AUROC for STTGMAFRAILTY for the high-energy and low-energy cohorts was 0.905 and 0.937, respectively. There was no significant difference in predictive capacity for inpatient mortality between STTGMAORIGINAL and STTGMAFRAILTY for both the high-energy and low-energy cohorts. Conclusion: The original STTGMA tool accounts for important frailty factors including cognition and general health status. These variables combined with other major physiologic variables such as age and anatomic injuries appear to be sufficient to adequately and accurately quantify inpatient mortality risk. The addition of other common frailty factors that account for does not enhance the STTGMA tool’s predictive capabilities.

The electronic structure and spin-charge separation of one-dimensional SrCuO2

2019 ◽  
Vol 33 (02) ◽  
pp. 1950006
Author(s):  
Huaisong Zhao ◽  
Jiasheng Qian ◽  
Sheng Xu ◽  
Feng Yuan
Keyword(s):  
Electronic Structure ◽  
Charge Separation ◽  
Energy Region ◽  
Doping Concentration ◽  
High Energy ◽  
Intermediate Energy ◽  
Low Energy ◽  
One Dimensional ◽  
High Energy Peak ◽  
Energy Peak

Based on the t-J model and slave-boson theory, we have studied the electronic structure in one-dimensional SrCuO2 by calculating the electron spectrum. Our results show that the electron spectra are mainly composed of three parts in one-dimensional SrCuO2, a sharp low-energy peak, a broad intermediate-energy peak and a high-energy peak. The sharp low-energy peak corresponds to the main band (MB) while the broad intermediate-energy peak and high-energy peak are associated with the shadow band (SB) and high-energy band (HB), respectively. From low-energy to intermediate-energy region, a clear two-peak structure (MB and SB) around the momentum [Formula: see text] appears, and the distance between two peaks decreases along the momentum direction from [Formula: see text] to [Formula: see text], then disappears at the critical momentum point [Formula: see text], leaving a single peak above [Formula: see text]. The electron spectral function in one-dimensional SrCuO2 is also the doping and temperature dependent. In particular, in the very low doping concentration, the HB merges into the MB. However, with the increases of the doping concentration, the HB separates from the MB and moves quickly to the high-binding energy region. The HB and MB are the direct results of the spin-charge separation while SB is the result of strong interaction between charge and spin parts. Therefore, our theoretical result predicts that the HB is more likely to be found at the low doping concentration, and it will be drowned in the background when the doping concentration is larger. Then with the temperature increases, the magnitude of the SB decreases, and it disappears at high temperature.

Parametrization of The Range of Electron At Low Energy (Eo < 10 Kev) Using The Casino Monte Carlo Program

1997 ◽  
Vol 3 (S2) ◽  
pp. 885-886 ◽  
Author(s):  
Pierre Hovington ◽  
Dominique Drouin ◽  
Raynald Gauvin ◽  
David C. Joy
Keyword(s):  
Monte Carlo ◽  
Atomic Number ◽  
Beam Energy ◽  
Energy Analysis ◽  
High Energy ◽  
Low Energy ◽  
Qualitative And Quantitative Analysis ◽  
Monte Carlo Program ◽  
Qualitative And Quantitative ◽  
Heterogeneous Samples

The range of electrons for a given beam energy and atomic number is one of the most valuable piece of information a microscopist must know before carrying out qualitative and quantitative analysis of heterogeneous samples in a scanning electron microscope (SEM). The frequently used parametrization of Kanaya & Okayama is only « valid » at high energy (EO > 10 keV). However, with the advent of Field Emission Gun SEM (FEGSEM) most of the effort has been toward low energy analysis where no parametrization is available yet. In this paper, the parametrization of the range of electrons at low energy as a function of atomic number and beam energy will be presented for both the backscattered and the internal electrons.The distribution of the maximum depth reached by 250 k electrons generated by the CASINO Monte Carlo program2 was used to compute the range for 10 elements at 20 energies.

Monte Carlo dosimetric evaluation of high energy vs low energy photon beams in low density tissues

2006 ◽  
Vol 79 (1) ◽  
pp. 131-138 ◽  
Author(s):  
Miltiadis F. Tsiakalos ◽  
Sotirios Stathakis ◽  
George A. Plataniotis ◽  
Constantin Kappas ◽  
Kiki Theodorou
Keyword(s):  
Monte Carlo ◽  
High Energy ◽  
Low Energy ◽  
Low Density ◽  
Photon Beams ◽  
Energy Photon

Towards parameter-free nanodosimetric quantities in the impact of highly ionizing radiation  

2021 ◽  
Author(s):  
Fabiana Da Pieve ◽  
Bin Gu ◽  
Natalia Koval ◽  
Daniel Muñoz Santiburcio ◽  
Jos Teunissen ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Radiation Effects ◽  
High Energy ◽  
Low Energy ◽  
Track Structure ◽  
Medical Patients ◽  
Radiation Physics ◽  
High Let Radiation ◽  
High Let ◽  
The Impact

&lt;p&gt;Cosmic Rays, in particular the high charge and high energy (HZE) particles and eventual secondary low energy protons, are high Linear Energy Transfer (LET) radiation, i.e. they transfer a high amount of energy to the target per unit path length travelled in the target itself, leaving behind a dense track of ionization and atomic excitations. Understanding the radiation physics and the biology induced by the impact of high LET radiation is of importance for different fields of research, such as radiation therapy with charged particles, space radiation protection of astronauts and of human explorers on Mars and eventually also survival of any bacterial, plant cell on other planetary/small bodies. While data for low LET radiation&amp;#160; such as X-ray have been studied in the survivors of the atomic-bombs, medical patients and nuclear reactor workers, for high LET radiation there is no relevant collection of human data for risk estimates, and experiments with nuclei created at accelerators are necessary.&lt;/p&gt;&lt;p&gt;At present we still do not have an understanding of how the&amp;#160; radiation&amp;#160; interaction&amp;#160; with a&amp;#160; single nanometric&amp;#160; target (units of DNA), the so-called track&amp;#160; structure [1],&amp;#160; should&amp;#160; decide&amp;#160; the&amp;#160; fate&amp;#160; of&amp;#160; the&amp;#160; irradiated cell. Monte Carlo (MC) track structure codes essentially work only with the physics given by impact cross sections on the sole water, there is no real consideration of the electronic/chemical characteristics of the hosted biomolecule [2]. Limitations given by such an approach have been highlighted [3], but on the positive side a massive effort is being done to follow the different steps of radiation effects up to biological damage [4].&lt;/p&gt;&lt;p&gt;In this contribution we would like to highlight how a chain of models from different communities could be of help to study the radiation effects on biomolecules. In particular, we will present how ab-initio (parameter-free) approaches from the chemical-physics community can be used to derive in detail the energy loss of the impacting ions/secondary electrons on water and small biological units [5,6], either following in real time the ion or based on perturbative theories for low energy electrons, and how the derived quantity can be given &amp;#160;as input to Monte Carlo track structure codes, extending their capabilities to different&amp;#160;relevant targets. Given the physical limitations and high costs of irradiation experiments, such calculations offer an efficient approach that can boost the understanding of radiation physics and consolidate existing MC track structure codes.&lt;/p&gt;&lt;p&gt;This work is initiated in the context of the EU H2020 project ESC2RAD, Grant 776410.&lt;/p&gt;&lt;p&gt;[1] H. Nikjoo, S. Uehara, W.E. Wilson, et al, International Journal of Radiation Biology 73, 355 (1998)&lt;/p&gt;&lt;p&gt;[2] H. Palmans, H Rabus, A L Belchior, et al, Br. J. Radiol. 88, 20140392 (2015)&lt;/p&gt;&lt;p&gt;[3] H. Rabus and H. Nettelback, Radiation Measurements 46, 1522 (2011)&lt;/p&gt;&lt;p&gt;[4] M. Karamitros, S. Luan, M.A. Bernal, et al,&amp;#160; Journal of Computational Physics 274,&amp;#160; 841 (2014)&lt;/p&gt;&lt;p&gt;[5] B. Gu, B. Cunningham D. Munoz-Santiburcio, F. Da Pieve, E. Artacho and J. Kohanoff, J. Chem. Phys. 153, 034113 (2020)&lt;/p&gt;&lt;p&gt;[6] N. Koval, J. Kohanoff, E. Artacho et al, in preparation&lt;/p&gt;

scholarly journals Simulating neutron transport in long beamlines at a spallation neutron source using Geant4

2020 ◽  
Vol 22 (2-3) ◽  
pp. 183-189
Author(s):  
Douglas D. DiJulio ◽  
Isak Svensson ◽  
Xiao Xiao Cai ◽  
Joakim Cederkall ◽  
Phillip M. Bentley
Keyword(s):  
Monte Carlo ◽  
Neutron Source ◽  
Variance Reduction ◽  
Neutron Transport ◽  
High Energy ◽  
Low Energy ◽  
Deep Penetration ◽  
Monte Carlo Code ◽  
Spallation Neutron Source ◽  
Unique Challenge

The transport of neutrons in long beamlines at spallation neutron sources presents a unique challenge for Monte-Carlo transport calculations. This is due to the need to accurately model the deep-penetration of high-energy neutrons through meters of thick dense shields close to the source and at the same time to model the transport of low- energy neutrons across distances up to around 150 m in length. Typically, such types of calculations may be carried out with MCNP-based codes or alternatively PHITS. However, in recent years there has been an increased interest in the suitability of Geant4 for such types of calculations. Therefore, we have implemented supermirror physics, a neutron chopper module and the duct-source variance reduction technique for low- energy neutron transport from the PHITS Monte-Carlo code into Geant4. In the current work, we present a series of benchmarks of these extensions with the PHITS software, which demonstrates the suitability of Geant4 for simulating long neutron beamlines at a spallation neutron source, such as the European Spallation Source, currently under construction in Lund, Sweden.

scholarly journals Neutronic Calculations for Certain Americium Mixed Fuels and Clads in a Boiling Water Reactor

2021 ◽  
Vol 9 ◽  
Author(s):  
Mehtap Düz
Keyword(s):  
Monte Carlo ◽  
Spent Nuclear Fuel ◽  
Reactor Core ◽  
Nuclear Data ◽  
Boiling Water ◽  
Square Lattice ◽  
Boiling Water Reactor ◽  
Water Reactor ◽  
Constant Pitch ◽  
Nuclear Data Library

In this study, a Boiling Water Reactor (BWR) design was made using the Monte Carlo (MCNPX) method. The reactor core in the designed BWR system was divided into an 8 × 8 square lattice with a constant pitch of 30.48 cm. In this study, americium (Am), which is found in the minor actinidine (MA) of spent nuclear fuel known as nuclear waste from existing reactors, was used as fuel with the addition of oxygen and fluorine. In this study, AmO2 and AmF3 fuels at the rate of 0.02–0.1% were used as Americium Mixed Fuels, and Zircaloy-2 (Zr-2), SiC, and VC were used as clad. Neutronic calculations for certain Americium Mixed Fuels and clads were compared in the designed BWR system. In the BWR system designed in the study; keff, neutron flux, fission energy, heating, and depleted Am were calculated. The three-dimensional (3-D) modeling of the designed BWR system was performed by using MCNPX-2.7.0 Monte Carlo method and the ENDF/B-VII.0 nuclear data library.

Channeling Study of the Damage Induced in Ion-Irradiated Ceramic Oxides

2003 ◽  
Vol 792 ◽  
Author(s):  
Lionel Thomé ◽  
Aurélie Gentils ◽  
Frédérico Garrido ◽  
Jacek Jagielski
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Single Crystals ◽  
Depth Distribution ◽  
Ion Irradiation ◽  
High Energy ◽  
Low Energy ◽  
Ceramic Oxides ◽  
Slowing Down ◽  
Crystalline Ceramic

ABSTRACTThe evaluation of the damage generated in crystalline ceramic oxides placed in a radiative environment is a major challenge in many technological domains. The use of the channeling technique is particularly well adapted to measure the depth distribution of the irradiation-induced disorder and to monitor the damage build-up. This paper describes the methodology used for the study of radiation damage with the channeling technique, presents a new method of analysis of channeling data based on Monte-Carlo simulations and provides recent results concerning the damage induced in ion-bombarded ceramic oxide single crystals in both nuclear (low-energy ion irradiation) and electronic (high-energy ion irradiation) slowing-down regimes.

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