Comparison of Geant4 multiple Coulomb scattering models with theory for radiotherapy protons.
Phys Med Biol
; 62(15): 5959-5974, 2017 Jul 06.
Article
em En
| MEDLINE
| ID: mdl-28682790
ABSTRACT
Usually, Monte Carlo models are validated against experimental data. However, models of multiple Coulomb scattering (MCS) in the Gaussian approximation are exceptional in that we have theories which are probably more accurate than the experiments which have, so far, been done to test them. In problems directly sensitive to the distribution of angles leaving the target, the relevant theory is the Molière/Fano/Hanson variant of Molière theory (Gottschalk et al 1993 Nucl. Instrum. Methods Phys. Res. B 74 467-90). For transverse spreading of the beam in the target itself, the theory of Preston and Koehler (Gottschalk (2012 arXiv1204.4470)) holds. Therefore, in this paper we compare Geant4 simulations, using the Urban and Wentzel models of MCS, with theory rather than experiment, revealing trends which would otherwise be obscured by experimental scatter. For medium-energy (radiotherapy) protons, and low-Z (water-like) target materials, Wentzel appears to be better than Urban in simulating the distribution of outgoing angles. For beam spreading in the target itself, the two models are essentially equal.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Prótons
/
Espalhamento de Radiação
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Planejamento da Radioterapia Assistida por Computador
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Método de Monte Carlo
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Modelos Teóricos
Tipo de estudo:
Health_economic_evaluation
Limite:
Humans
Idioma:
En
Revista:
Phys Med Biol
Ano de publicação:
2017
Tipo de documento:
Article
País de afiliação:
Japão