Monte Carlo and Analytic Methods in the Transport of Electrons, Neutrons, and Alpha Particles

1994 ◽  
pp. 115-136
Author(s):  
Randall S. Caswell ◽  
Stephen M. Seltzer
Keyword(s):  
Monte Carlo ◽  
Alpha Particles ◽  
Analytic Methods

Monte Carlo modeling of production of three alpha-particles in low energy n +12C interactions

2021 ◽  
Vol 36 (25) ◽  
pp. 2150182
Author(s):  
Khusniddin K. Olimov ◽  
Vladimir V. Lugovoi ◽  
Kosim Olimov ◽  
Maratbek Shodmonov ◽  
Kadyr G. Gulamov ◽  
...  
Keyword(s):  
Experimental Data ◽  
Monte Carlo ◽  
Monte Carlo Model ◽  
Three Dimensional ◽  
Alpha Particles ◽  
Incident Neutron ◽  
Excitation Energies ◽  
Collision Event ◽  
Direct Decay ◽  
Calculation Results

To describe [Formula: see text] interactions with production of three [Formula: see text]-particles at incident neutron kinetic energy of 14 MeV in a nuclear (photo) emulsion, a Monte Carlo model is proposed for four channels of decay of an excited carbon-12 nucleus into three [Formula: see text]-particles. The Monte Carlo calculation results describe well the experimental data on the distribution of the angle between the three-dimensional momenta of all pairs of [Formula: see text]-particles in a collision event, on the distribution of the angle between the projections of the momentum vectors of all pairs of [Formula: see text]-particles in collision event on each of the coordinate planes, on the distribution of the sum of the kinetic energies of all pairs of [Formula: see text]-particles in a collision event, and the distribution of projections of the momenta of [Formula: see text]-particles on the coordinate planes. The best agreement of the Monte Carlo model results with the experimental data is achieved if the direct decay [Formula: see text] and decay through the formation of an intermediate beryllium nucleus [Formula: see text] are generated with equal probabilities, while the excitation energies of 3.04 MeV, 1.04 MeV, and 0.1 MeV for the beryllium nucleus are generated with relative weights of 75%, 15%, and 10%, respectively.

Determination of CR-39 and LR-115 Type II Mean Critical Angle of Etching Using a New Monte Carlo Code

2020 ◽  
Author(s):  
Hicham Harrass ◽  
Abdellatif Talbi ◽  
Rodouan Touti
Keyword(s):  
Monte Carlo ◽  
Alpha Particle ◽  
Critical Angle ◽  
Current Method ◽  
Particle Energy ◽  
Alpha Particles ◽  
Monte Carlo Code ◽  
Type Ii ◽  
Alpha Particle Energy ◽  
The Mean

Abstract CR-39 and LR-115 type II solid state nuclear track detectors (SSNTDs) are both used, in order to assess the concentration of nucleus belonging to 238U and 232Th series, these ones can be also used to measure radon 222Rn and thoron 220Rn gases in different locations. In this paper, a Monte Carlo code was developed to calculate the mean critical angle for which alpha particles emitted from 238U and 232Th families in studied material samples reach CR-39 and LR-115 type II surfaces and bring about latent tracks on them. The dependence of the SSNTDs mean critical angle on the removed thickness, the initial alpha particle energy has been studied. A linear relationship between CR-39 mean critical angle and the initial alpha particle energy for different removed thicknesses has been found. This straightforward relationship allows determining quickly the mean critical angle of etching which corresponds to initial alpha particle energy for a given removed thickness. CR-39 mean critical angle ranged from 59° for an alpha particle emitted by 212Po to 71° for an alpha particle emitted by 232Th, for the value of removed thickness of 6 µm; whereas LR-115 type II mean critical angle does not depend on the initial alpha particle energy except for 232Th, 238U, 230Th and 234Ra when the removed thickness ranged from 6 µm to 8 µm. Obtained data by using the current method and those obtained in the literature [18] are in good agreement with each other.

Recoil proton, alpha particle, and heavy ion impacts on microdosimetry and RBE of fast neutrons: analysis of kerma spectra calculated by Monte Carlo simulation

2001 ◽  
Vol 79 (2) ◽  
pp. 189-195 ◽  
Author(s):  
Jean-Philippe Pignol ◽  
Jakobus Slabbert
Keyword(s):  
Monte Carlo ◽  
Recoil Proton ◽  
Clinical Results ◽  
Heavy Ion ◽  
Alpha Particles ◽  
Fast Neutrons ◽  
Monte Carlo Code ◽  
Powerful Method ◽  
Biological Effectiveness

Fast neutrons (FN) have a higher radio-biological effectiveness (RBE) compared with photons, however the mechanism of this increase remains a controversial issue. RBE variations are seen among various FN facilities and at the same facility when different tissue depths or thicknesses of hardening filters are used. These variations lead to uncertainties in dose reporting as well as in the comparisons of clinical results. Besides radiobiology and microdosimetry, another powerful method for the characterization of FN beams is the calculation of total proton and heavy ion kerma spectra. FLUKA and MCNP Monte Carlo code were used to simulate these kerma spectra following a set of microdosimetry measurements performed at the National Accelerator Centre. The calculated spectra confirmed major classical statements: RBE increase is linked to both slow energy protons and alpha particles yielded by (n,α) reactions on carbon and oxygen nuclei. The slow energy protons are produced by neutrons having an energy between 10 keV and 10 MeV, while the alpha particles are produced by neutrons having an energy between 10 keV and 15 MeV. Looking at the heavy ion kerma from <15 MeV and the proton kerma from neutrons <10 MeV, it is possible to anticipate y* and RBE trends.Key words: fast neutron, kerma, microdosimetry, RBE, Monte Carlo.

scholarly journals Alpha-particle fluence in radiobiological experiments

2016 ◽  
Vol 58 (2) ◽  
pp. 195-200
Author(s):  
Dragoslav Nikezic ◽  
Kwan Ngok Yu
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Alpha Particle ◽  
Track Detector ◽  
Alpha Particles ◽  
Target Distance ◽  
Nuclear Track Detector ◽  
241Am Source ◽  
Particle Tracks ◽  
Carbonate Film

Abstract Two methods were proposed for determining alpha-particle fluence for radiobiological experiments. The first involved calculating the probabilities of hitting the target for alpha particles emitted from a source through Monte Carlo simulations, which when multiplied by the activity of the source gave the fluence at the target. The second relied on the number of chemically etched alpha-particle tracks developed on a solid-state nuclear track detector (SSNTD) that was irradiated by an alpha-particle source. The etching efficiencies (defined as percentages of latent tracks created by alpha particles from the source that could develop to become visible tracks upon chemical etching) were computed through Monte Carlo simulations, which when multiplied by the experimentally counted number of visible tracks would also give the fluence at the target. We studied alpha particles with an energy of 5.486 MeV emitted from an 241Am source, and considered the alpha-particle tracks developed on polyallyldiglycol carbonate film, which is a common SSNTD. Our results showed that the etching efficiencies were equal to one for source–film distances of from 0.6 to 3.5 cm for a circular film of radius of 1 cm, and for source–film distances of from 1 to 3 cm for circular film of radius of 2 cm. For circular film with a radius of 3 cm, the etching efficiencies never reached 1. On the other hand, the hit probability decreased monotonically with increase in the source–target distance, and fell to zero when the source–target distance was larger than the particle range in air.

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