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.

Dosimetric characterization of an 192Ir brachytherapy source with the Monte Carlo code PENELOPE

2010 ◽  
Vol 26 (3) ◽  
pp. 132-139 ◽  
Author(s):  
Francisco Javier Casado ◽  
Salvador García-Pareja ◽  
Elena Cenizo ◽  
Beatriz Mateo ◽  
Coral Bodineau ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Code ◽  
Brachytherapy Source

scholarly journals Characterization of materials for prosthetic implants using the BEAMnrc Monte Carlo code

2007 ◽  
Vol 74 ◽  
pp. 021016 ◽  
Author(s):  
E Spezi ◽  
F Palleri ◽  
A L Angelini ◽  
A Ferri ◽  
F Baruffaldi
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Code ◽  
Prosthetic Implants ◽  
Characterization Of Materials

Development of Heavy Ion Transport Monte Carlo Code

2001 ◽  
pp. 973-978
Author(s):  
H. Iwase ◽  
T. Kurosawa ◽  
T. Nakamura ◽  
N. Yoshizawa ◽  
J. Funabiki
Keyword(s):  
Monte Carlo ◽  
Ion Transport ◽  
Heavy Ion ◽  
Monte Carlo Code

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.

scholarly journals Multi-scaled Monte Carlo calculation for radon-induced cellular damage in the bronchial airway epithelium

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ali Abu Shqair ◽  
Eun-Hee Kim
Keyword(s):  
Monte Carlo ◽  
Airway Epithelium ◽  
Bronchial Epithelium ◽  
Cell Types ◽  
Alpha Particles ◽  
Cellular Damage ◽  
Monte Carlo Code ◽  
Basal Cells ◽  
Cell Nuclei ◽  
Daily Work

AbstractRadon is a leading cause of lung cancer in indoor public and mining workers. Inhaled radon progeny releases alpha particles, which can damage cells in the airway epithelium. The extent and complexity of cellular damage vary depending on the alpha particle’s kinetic energy and cell characteristics. We developed a framework to quantitate the cellular damage on the nanometer and micrometer scales at different intensities of exposure to radon progenies Po-218 and Po-214. Energy depositions along the tracks of alpha particles that were slowing down were simulated on a nanometer scale using the Monte Carlo code Geant4-DNA. The nano-scaled track histories in a 5 μm radius and 1 μm-thick cylindrical volume were integrated into the tracking scheme of alpha trajectories in a micron-scale bronchial epithelium segment in the user-written SNU-CDS program. Damage distribution in cellular DNA was estimated for six cell types in the epithelium. Deep-sited cell nuclei in the epithelium would have less chance of being hit, but DNA damage from a single hit would be more serious, because low-energy alpha particles of high LET would hit the nuclei. The greater damage in deep-sited nuclei was due to the 7.69 MeV alpha particles emitted from Po-214. From daily work under 1 WL of radon concentration, basal cells would respond with the highest portion of complex DSBs among the suspected progenitor cells in the most exposed regions of the lung epithelium.

Development of heavy ion transport Monte Carlo code

2001 ◽  
Vol 183 (3-4) ◽  
pp. 374-382 ◽  
Author(s):  
Hiroshi Iwase ◽  
Tadahiro Kurosawa ◽  
Takashi Nakamura ◽  
Nobuaki Yoshizawa ◽  
Jun Funabiki
Keyword(s):  
Monte Carlo ◽  
Ion Transport ◽  
Heavy Ion ◽  
Monte Carlo Code

scholarly journals Development of Heavy Ion Transport Monte Carlo Code

2000 ◽  
Vol 37 (sup1) ◽  
pp. 142-145
Author(s):  
Hiroshi Iwase ◽  
Tadahiro Kurosawa ◽  
Takashi Nakamura ◽  
Nobuaki Yoshizawa ◽  
Jun Funabiki
Keyword(s):  
Monte Carlo ◽  
Ion Transport ◽  
Heavy Ion ◽  
Monte Carlo Code

scholarly journals Development of Heavy Ion Transport Monte Carlo Code

2002 ◽  
Vol 39 (sup2) ◽  
pp. 1013-1016
Author(s):  
Hiroshi Iwase ◽  
Tadahiro Kurosawa ◽  
Michiya Sasaki ◽  
Takashi Nakamura ◽  
Nobuaki Yoshizawa ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Ion Transport ◽  
Heavy Ion ◽  
Monte Carlo Code

scholarly journals Microdosimetry and Dose-Averaged LET Calculations of Protons in Liquid Water: A Novel Geant4-DNA Application

2021 ◽  
Vol 9 ◽  
Author(s):  
Anna Baratto-Roldán ◽  
Alejandro Bertolet ◽  
Giorgio Baiocco ◽  
Alejandro Carabe ◽  
Miguel Antonio Cortés-Giraldo
Keyword(s):  
Monte Carlo ◽  
Liquid Water ◽  
Energy Deposition ◽  
Cellular Level ◽  
Proton Track ◽  
Biological Effectiveness ◽  
Radiobiological Effects ◽  
Quantities Of Interest

The spatial distribution of energy deposition events is an essential aspect in the determination of the radiobiological effects of ionizing radiation at the cellular level. Microdosimetry provides a theoretical framework for the description of these events, and has been used in several studies to address problems such as the characterization of Linear Energy Transfer (LET) and Relative Biological Effectiveness (RBE) of ion beams for proton therapy applications. Microdosimetry quantities and their distributions can be obtained by means of Monte Carlo simulations. In this work, we present a track structure Monte Carlo (MC) application, based on Geant4-DNA, for the computation of microdosimetric distributions of protons in liquid water. This application provides two sampling methods uniform and weighted, for the scoring of the quantities of interest in spherical sites, with diameters ranging from 1 to 10 μm. As an element of novelty, the work shows the approach followed to calculate, without resorting to dedicated simulations, the distribution of energy imparted to the site per electronic collision of the proton, which can be used to obtain the macroscopic dose-averaged LET as proposed by Kellerer. Furthermore, in this work the concept of effective mean chord length is proposed to take into account δ-ray influx and escape in the calculation of macroscopic dose-averaged LET for proton track segments and retrieve the agreement predicted by Kellerer’s formula. Finally, the results obtained demonstrate that our MC application is reliable and computational-efficient to perform calculations of microdosimetric distributions and dose-averaged LET of proton track segments in liquid water.

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