Study of Photoneutron Production for the 18 MV Photon Beam of the Siemens Medical linac by Monte Carlo Simulation.
18 MV Photon Beam
Electrons
Monte Carlo Method
Neutron Contamination
Neutron Source Strength
Particle Accelerators
Proton Spectrum
Journal
Journal of biomedical physics & engineering
ISSN: 2251-7200
Titre abrégé: J Biomed Phys Eng
Pays: Iran
ID NLM: 101589641
Informations de publication
Date de publication:
Dec 2020
Dec 2020
Historique:
received:
13
05
2018
accepted:
05
06
2018
entrez:
28
12
2020
pubmed:
29
12
2020
medline:
29
12
2020
Statut:
epublish
Résumé
Considering the importance of photoneutron production in linear accelerators, it is necessary to describe and measure the photoneutrons produced around modern linear accelerators. The aim of the present research is to study photoneutron production for the 18 MV photon beam of a Siemens Primus Plus medical linear accelerator. This study is an experimental study. The main components of the head of Siemens Primus Plus linac were simulated using MCNPX 2.7.0 code. The contribution of different components of the linac in photoneutron production, neutron source strength, neutron source strength and photon and electron spectra were calculated for the flattening filter and flattening filter free cases for the 18 MV photon beam, and was scored for three fields of 5 × 5 cm The results show that the primary collimator has the largest contribution to production of neutrons. Moreover, the photon fluence for the flattening filter free case is 8.62, 6.51 and 4.62 times higher than the flattening filter case for the three fields, respectively. The electron fluences for the flattening filter free case are 4.62, 2.93 and 2.79 times higher than with flattening filter case for the three fields under study, respectively. In addition to these cases, by increasing the field size, the contribution of neutron production related to the jaws is reduced, so that when the field size increases from 5 × 5 cm In all of the accelerators, the neutron strength also increases with increasing energy. The calculated neutron strength was equal to 0.83×10
Sections du résumé
BACKGROUND
BACKGROUND
Considering the importance of photoneutron production in linear accelerators, it is necessary to describe and measure the photoneutrons produced around modern linear accelerators.
OBJECTIVE
OBJECTIVE
The aim of the present research is to study photoneutron production for the 18 MV photon beam of a Siemens Primus Plus medical linear accelerator.
MATERIAL AND METHODS
METHODS
This study is an experimental study. The main components of the head of Siemens Primus Plus linac were simulated using MCNPX 2.7.0 code. The contribution of different components of the linac in photoneutron production, neutron source strength, neutron source strength and photon and electron spectra were calculated for the flattening filter and flattening filter free cases for the 18 MV photon beam, and was scored for three fields of 5 × 5 cm
RESULTS
RESULTS
The results show that the primary collimator has the largest contribution to production of neutrons. Moreover, the photon fluence for the flattening filter free case is 8.62, 6.51 and 4.62 times higher than the flattening filter case for the three fields, respectively. The electron fluences for the flattening filter free case are 4.62, 2.93 and 2.79 times higher than with flattening filter case for the three fields under study, respectively. In addition to these cases, by increasing the field size, the contribution of neutron production related to the jaws is reduced, so that when the field size increases from 5 × 5 cm
CONCLUSION
CONCLUSIONS
In all of the accelerators, the neutron strength also increases with increasing energy. The calculated neutron strength was equal to 0.83×10
Identifiants
pubmed: 33364205
doi: 10.31661/JBPE.V0I0.939
pii: JBPE-10-6
pmc: PMC7753258
doi:
Types de publication
Journal Article
Langues
eng
Pagination
679-690Informations de copyright
Copyright: © Journal of Biomedical Physics and Engineering.
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