Nanodosimetry-based quality factors for radiation protection in space

Schulte, R.; Wroe, Andrew; Bashkirov, V.; Garty, Guy; Breskin, A.; Chechik, R.; Shchemelinin, S.; Gargioni, E.; Großwendt, B.; Rosenfeld, Anatoly B.

doi:10.1016/j.zemedi.2008.06.011

Cited by 29 publications

(18 citation statements)

References 29 publications

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“…In nanodosimetry, the unique track structure of a specific radiation quality Q is characterised by the probability distribution P(ν |Q) of the ionisation cluster size ν, which is defined as the number of ionisations produced by a single particle track within a specified target volume (Grosswendt 2002, Grosswendt andPszona 2002). In common practice, the target volume is assumed to be filled with and surrounded by liquid water (Nikjoo and Goodhead 1991, Grosswendt 2002, Schulte et al 2008. The probability distribution P(ν |Q) describes the probability that exactly ν ionisations are produced per primary particle of radiation quality Q.…”

Section: Nanodosimetric Parameters Of Track Structure (Npts)mentioning

confidence: 99%

“…Such capability is possible with the PTB Monte Carlo track structure code and with Geant4-DNA. The PTB MC code was specifically developed and is well established for nanodosimetry (Grosswendt and Pszona 2002, Schulte et al 2008, Bashkirov et al 2009, Garty et al 2010. Geant4 is the only open-source, general-purpose Monte Carlo code system and the recently released Geant4-DNA Very Low Energy physical interaction models provide a potential capability for nanodosimetry applications (Agostinelli et al 2003, Allison et al 2006, Chauvie et al 2007.…”

Section: Track Structure Monte Carlo Simulationmentioning

confidence: 99%

“…With increasing LET, the number of energy deposition events per path length increases. This involves, among other processes, a higher number of ionisation events within small segments of DNA and, as a biological consequence, a high number of DNA strand breaks (Grosswendt 2005, Schulte et al 2008. Commonly, a double strand break (DSB) is defined as two strand breaks occurring on opposite DNA strands at a distance of up to 10 base pairs (Grosswendt 2002).…”

Section: Introductionmentioning

confidence: 99%

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Comparison of nanodosimetric parameters of track structure calculated by the Monte Carlo codes Geant4-DNA and PTra

et al. 2012

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The concept of nanodosimetry is based on the assumption that initial damage to cells is related to the number of ionisations (the ionisation cluster size) directly produced by single particles within, or in the close vicinity of, short segments of DNA. The ionisation cluster size distribution and other nanodosimetric quantities, however, are not directly measurable in biological targets and our present knowledge is mostly based on numerical simulations of particle tracks in water, calculating track structure parameters for nanometric target volumes. The assessment of nanodosimetric quantities derived from particle-track calculations using different Monte Carlo codes plays therefore an important role for a more accurate evaluation of the initial damage to cells and, as a consequence, of the biological effectiveness of ionising radiation. The aim of this work is to assess the differences in the calculated nanodosimetric quantities obtained with Geant4-DNA as compared to those of an ad-hoc particle-track Monte Carlo code developed at PTB. The comparison of the two codes was done for incident electrons of energy in the range between 50 eV and 10 keV, for protons of energy between 300 keV and 10 MeV, and for alpha particles of energy between 1 MeV and 10 MeV. Good agreement was found for nanodosimetric characteristics of track structure calculated in the high energy range of each particle type. For lower energies, significant differences were observed, most notably in the estimates of the biological effectiveness The largest relative differences obtained were over 50 %, however generally the order of magnitude was between 10 % and 20 %. P. Lazarakis et al.:Comparison of nanodosimetric parameters of track structure calculated by Geant4-DNA and PTB … 3 / 34

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Section: Nanodosimetric Parameters Of Track Structure (Npts)mentioning

confidence: 99%

Section: Track Structure Monte Carlo Simulationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Comparison of nanodosimetric parameters of track structure calculated by the Monte Carlo codes Geant4-DNA and PTra

et al. 2012

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“…The track structure code PTra (version PTra-h2o-1201) was used, which was specifically developed and is well established for nanodosimetry [7,11,13]. A comprehensive description of the particle transport in such kinds of simulations is provided in [6-8, 10, 12, 14] and therefore omitted in this paper.…”

Section: Ptra Simulationmentioning

confidence: 99%

Nanoscale characterization of ion tracks: MC simulations versus analytical approach

et al. 2012

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The goal of this work was to investigate the agreement of physical parameters related to the particle track structure on the nanometer scale, obtained by means of a detailed track structure simulation (PTra) as well as by a rapid analytical approach. Parameters describing the tracks of secondary electrons produced by 0.3 MeV/ u C6+-ions were of particular interest as those particles are densely ionizing. For this purpose, the target volume in form of a nanometric water cylinder was positioned at different radial distances from the ion trajectory and track structure parameters were determined as function of the radial distance. While the fluence of electrons through the target surface and the mean ionization cluster size obtained by both approaches were in good agreement, the probabilities of specific cluster sizes (one, two and three) turned out to be rather different in the two approaches. Abstract. The scope of this work was to investigate the agreement of physical parameters related to the particle track structure on the nanometer scale, obtained by means of a detailed track structure simulation (PTra) as well as by a rapid analytical approach. Parameters describing the tracks of secondary electrons produced by 0.3 MeV/u C 6+ -ions were of particular interest as those particles are densely ionizing. For this purpose, the target volume in form of a nanometric water cylinder was positioned at different radial distances from the ion trajectory and track structure parameters were determined as function of the radial distance. While the fluence of electrons through the target surface and the mean ionization cluster size obtained by both approaches were in good agreement, the probabilities of specific cluster sizes (one, two and three) turn out to be rather different in the two approaches.

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“…Micro-and nanodosimetric approaches have been under development for several years [1][2][3][4][5][6] as a means to characterize the track structure of ionizing radiation. This characterization is particularly important for an estimation of initial radiationinduced biological effects on the microscopic scale.…”

Section: Introductionmentioning

confidence: 99%

Ionization cross section data of nitrogen, methane, and propane for light ions and electrons and their suitability for use in track structure simulations

et al. 2013

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Rabus, H. (2013). Ionization cross section data of nitrogen, methane, and propane for light ions and electrons and their suitability for use in track structure simulations. Physical Review E: Statistical, Nonlinear, and Soft Matter Physics, 88 (4), 043308-1-043308-21.Ionization cross section data of nitrogen, methane, and propane for light ions and electrons and their suitability for use in track structure simulations AbstractTrack structure Monte Carlo simulations are frequently applied in micro-and nanodosimetry to calculate the radiation transport in detail. The use of a well-validated set of cross section data in such simulation codes ensures accurate calculations of transport parameters, such as ionization yields. These cross section data are, however, scarce and often discrepant when measured by different groups. This work surveys literature data on ionization and charge-transfer cross sections of nitrogen, methane, and propane for electrons, protons, and helium particles, focusing on the energy range between 100 keV and 20 MeV. Based on the evaluated data, different models for the parametrization of the cross section data are implemented in the code PTRA, developed for simulating proton and alpha particle transport in an ion-counting nanodosimeter. The suitability of the cross section data is investigated by comparing the calculated mean ionization cluster size and energy loss with experimental results in either nitrogen or propane. For protons, generally good agreement between measured and simulated data is found when the Rudd model is used in PTRA. For alpha particles, however, a considerable influence of different parametrizations of cross sections for ionization and charge transfer is observed. The PTRA code using the charge-transfer data is, nevertheless, successfully benchmarked by the experimental data for the calculation of nanodosimetric quantities, but remaining discrepancies still have to be further investigated (up to 13% lower energy loss and 19% lower mean ionization cluster size than in the experiment). A continuation of this work should investigate data for the energy loss per interaction as well as differential cross section data of nitrogen and propane. Interpolation models for ionization and chargetransfer data are proposed. The Barkas model, frequently used for a determination of the effective charge in the ionization cross section, significantly underestimates both the energy loss (by up to 19%) and the mean ionization cluster size (up to 65%) for alpha particles. It is, therefore, not recommended for particle-track simulations. Track structure Monte Carlo simulations are frequently applied in micro-and nanodosimetry to calculate the radiation transport in detail. The use of a well-validated set of cross section data in such simulation codes ensures accurate calculations of transport parameters, such as ionization yields. These cross section data are, however, scarce and often discrepant when measured by different groups. This work surveys literature data on ionization and charge-tra...

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Nanodosimetry-based quality factors for radiation protection in space

Cited by 29 publications

References 29 publications

Comparison of nanodosimetric parameters of track structure calculated by the Monte Carlo codes Geant4-DNA and PTra

Comparison of nanodosimetric parameters of track structure calculated by the Monte Carlo codes Geant4-DNA and PTra

Nanoscale characterization of ion tracks: MC simulations versus analytical approach

Ionization cross section data of nitrogen, methane, and propane for light ions and electrons and their suitability for use in track structure simulations

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