scholarly journals MCHP (Monte Carlo + Human Phantom): Platform to facilitate teaching nuclear radiation physics

PLoS ONE ◽  
2021 ◽  
Vol 16 (9) ◽  
pp. e0257638
Author(s):  
Mehrdad Shahmohammadi Beni ◽  
Hiroshi Watabe ◽  
Dragana Krstic ◽  
Dragoslav Nikezic ◽  
Kwan Ngok Yu
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Adult Male ◽  
National Laboratory ◽  
Nuclear Radiation ◽  
Radiation Physics ◽  
Oak Ridge ◽  
Video Clips ◽  
Ionizing Radiations ◽  
Physics Course

Some concepts in nuclear radiation physics are abstract and intellectually demanding. In the present paper, an “MCHP platform” (MCHP was an acronym for Monte Carlo simulations + Human Phantoms) was proposed to provide assistance to the students through visualization. The platform involved Monte Carlo simulations of interactions between ionizing radiations and the Oak Ridge National Laboratory (ORNL) adult male human phantom. As an example to demonstrate the benefits of the proposed MCHP platform, the present paper investigated the variation of the absorbed photon dose per photon from a 137Cs source in three selected organs, namely, brain, spine and thyroid of an adult male for concrete and lead shields with varying thicknesses. The results were interesting but not readily comprehensible without direct visualization. Graphical visualization snapshots as well as video clips of real time interactions between the photons and the human phantom were presented for the involved cases, and the results were explained with the help of such snapshots and video clips. It is envisaged that, if the platform is found useful and effective by the readers, the readers can also propose examples to be gradually added onto this platform in future, with the ultimate goal of enhancing students’ understanding and learning the concepts in an undergraduate nuclear radiation physics course or a related course.

scholarly journals Organ doses for reference adult male and female undergoing computed tomography estimated by Monte Carlo simulations

2011 ◽  
Vol 38 (3) ◽  
pp. 1196-1206 ◽  
Author(s):  
Choonsik Lee ◽  
Kwang Pyo Kim ◽  
Daniel Long ◽  
Ryan Fisher ◽  
Chris Tien ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Adult Male ◽  
Organ Doses ◽  
Male And Female

Monte Carlo simulations for the evaluation of various influence factors on projections in computed tomography

2010 ◽  
Vol 25 (2) ◽  
pp. 165-168
Author(s):  
B. Chyba ◽  
M. Mantler ◽  
M. Reiter
Keyword(s):  
Computed Tomography ◽  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
National Laboratory ◽  
Light Yield ◽  
Thin Layers ◽  
Detector Response ◽  
X Rays ◽  
Los Alamos ◽  
X Ray

This paper presents Monte Carlo simulations considering all stages of the creation process of two-dimensional projections in a computed tomography (CT) device: excitation of angle dependent X-ray spectra within the X-ray tube using results from a previous study [Chyba et al. (2008). Powder Diffr. 23, 150–153]; interaction of these X-rays and secondary photoelectrons with a simple inhomogeneous sample; and interaction of X-rays and photoelectrons with the components (thin layers) of a matrix scintillation detector. The simulations were carried out by using custom software running on up to 50 nodes of a computer cluster. Comparative calculations were also made by using the software package MCNP [Booth et al. (2003). MCNP—A general Monte Carlo N-particle transport code, Report LAUR 03-1987, Los Alamos National Laboratory, Los Alamos, NM]. Tube spectra were calculated with algorithms proposed by Ebel [(2006). Adv. X-Ray Anal. 49, 267–273]. Measurements for the chosen setup made with an available CT device were in relatively good agreement with calculated results. It was shown that good knowledge of the tube spectra is of importance, but most differences between resulting projections and measurements are caused by uncertainties concerning detector response due to light yield of the scintillator and to internal scattering effects within the thin detector layers which lead to spreading of a detected point signal within the detector matrix into neighboring matrix elements.

scholarly journals CONTINUOUS ENERGY COMET SOLUTION TO A SMALL MODULAR ADVANCED HIGH-TEMPERATURE REACTOR BENCHMARK PROBLEM (SmAHTR)

2021 ◽  
Vol 247 ◽  
pp. 05002
Author(s):  
Farzad Rahnema ◽  
Dingkang Zhang
Keyword(s):  
Monte Carlo ◽  
High Temperature ◽  
National Laboratory ◽  
Benchmark Problems ◽  
High Fidelity ◽  
Oak Ridge ◽  
Continuous Energy ◽  
High Temperature Reactor ◽  
Relative Differences ◽  
High Computational Efficiency

The continuous energy coarse mesh transport (COMET) method is a hybrid stochasticdeterministic solver that provides transport solutions to heterogeneous reactor cores. In this paper, COMET is tested against continuous energy Monte Carlo in solving the recently developed stylized Small Modular Advanced High-Temperature Reactor (SmAHTR) Benchmark Problems based on the Oak Ridge National Laboratory pre-conceptual design (core configurations). These problems are well-suited to test the performance of advanced neutronics tools because of their unique neutronics characteristics such as the multiple heterogeneities. The COMET solutions for the three benchmark problems were found to agree very well with the continuous energy Monte Carlo reference solutions. The discrepancy in the core eigenvalue (k-eff) varied from 40 pcm to 51 pcm. The average and maximum relative differences in the pin fission densities were in the range of 0.20% to 0.21% and 0.77% to 0.94%, respectively. It was also found that COMET was more than 2,000 times fast than MCNP. It can be concluded that COMET can model the SmAHTR core configuration with high fidelity and significantly high computational efficiency.

scholarly journals A comparative study on dispersed doses during photon and proton radiation therapy in pediatric applications

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0248300
Author(s):  
Mehrdad Shahmohammadi Beni ◽  
Dragana Krstic ◽  
Dragoslav Nikezic ◽  
Kwan Ngok Yu
Keyword(s):  
Monte Carlo ◽  
Radiation Therapy ◽  
National Laboratory ◽  
Left Lung ◽  
Photon Radiation ◽  
Track Length ◽  
Proton Radiation ◽  
Oak Ridge ◽  
Proton Radiation Therapy ◽  
Pediatric Cancer Patients

The Monte Carlo method was employed to simulate realistic treatment situations for photon and proton radiation therapy for a set of Oak Ridge National Laboratory (ORNL) pediatric phantoms for 15, 10, 5 and 1-year olds as well as newborns. Complete radiotherapy situations were simulated using the previously developed NRUrad input code for Monte Carlo N-Particle (MCNP) code package. Each pediatric phantom was irradiated at five different positions, namely, the testes, colon, liver, left lung and brain, and the doses in targeted organs (Dt) were determined using the track length estimate of energy. The dispersed photon and proton doses in non-targeted organs (Dd), namely, the skeleton, skin, brain, spine, left and right lungs were computed. The conversion coefficients (F = Dd/Dt) of the dispersed doses were used to study the dose dispersion in different non-targeted organs for phantoms for 15, 10, 5 and 1-year olds as well as newborns. In general, the F values were larger for younger patients. The F values for non-targeted organs for phantoms for 1-year olds and newborns were significantly larger compared to those for other phantoms. The dispersed doses from proton radiation therapy were also found to be significantly lower than those from conventional photon radiation therapy. For example, the largest F values for the brain were 65.6% and 0.206% of the dose delivered to the left lung (P4) for newborns during photon and proton radiation therapy, respectively. The present results demonstrated that dispersion of photons and generated electrons significantly affected the absorbed doses in non-targeted organs during pediatric photon therapy, and illustrated that proton therapy could in general bring benefits for treatment of pediatric cancer patients.

Plug-in scripts for EFTEM automation

1996 ◽  
Vol 54 ◽  
pp. 546-547
Author(s):  
N. D. Evans ◽  
M. K. Kundmann
Keyword(s):  
Electron Microscopy ◽  
National Laboratory ◽  
Oak Ridge ◽  
Multiple User ◽  
Transmission Electron ◽  
Short Period ◽  
User Facility ◽  
Instrument Control ◽  
And Control ◽  
Research Equipment

Post-column energy-filtered transmission electron microscopy (EFTEM) is inherently challenging as it requires the researcher to setup, align, and control both the microscope and the energy-filter. The software behind an EFTEM system is therefore critical to efficient, day-to-day application of this technique. This is particularly the case in a multiple-user environment such as at the Shared Research Equipment (SHaRE) User Facility at Oak Ridge National Laboratory. Here, visiting researchers, who may oe unfamiliar with the details of EFTEM, need to accomplish as much as possible in a relatively short period of time.We describe here our work in extending the base software of a commercially available EFTEM system in order to automate and streamline particular EFTEM tasks. The EFTEM system used is a Philips CM30 fitted with a Gatan Imaging Filter (GIF). The base software supplied with this system consists primarily of two Macintosh programs and a collection of add-ons (plug-ins) which provide instrument control, imaging, and data analysis facilities needed to perform EFTEM.

Low-voltage EDS of magnesium ferrite Dendrites in a FEG-SEM

1996 ◽  
Vol 54 ◽  
pp. 478-479
Author(s):  
Matthew T. Johnson ◽  
Ian M. Anderson ◽  
Jim Bentley ◽  
C. Barry Carter
Keyword(s):  
Monte Carlo ◽  
Quantitative Analysis ◽  
Monte Carlo Simulations ◽  
Cross Section ◽  
Spatial Resolution ◽  
Low Voltage ◽  
Magnesium Ferrite ◽  
X Ray ◽  
Interaction Volume ◽  
Ferrite Spinel

Energy-dispersive X-ray spectrometry (EDS) performed at low (≤ 5 kV) accelerating voltages in the SEM has the potential for providing quantitative microanalytical information with a spatial resolution of ∼100 nm. In the present work, EDS analyses were performed on magnesium ferrite spinel [(MgxFe1−x)Fe2O4] dendrites embedded in a MgO matrix, as shown in Fig. 1. spatial resolution of X-ray microanalysis at conventional accelerating voltages is insufficient for the quantitative analysis of these dendrites, which have widths of the order of a few hundred nanometers, without deconvolution of contributions from the MgO matrix. However, Monte Carlo simulations indicate that the interaction volume for MgFe2O4 is ∼150 nm at 3 kV accelerating voltage and therefore sufficient to analyze the dendrites without matrix contributions.Single-crystal {001}-oriented MgO was reacted with hematite (Fe2O3) powder for 6 h at 1450°C in air and furnace cooled. The specimen was then cleaved to expose a clean cross-section suitable for microanalysis.

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