Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
An energy-loss model for low- and intermediate-energy carbon projectiles in water
Karolinska Institutet, Institutionen för onkologi-patologi .
Karolinska Institutet, Institutionen för onkologi-patologi.
2012 (English)In: International Journal of Radiation Biology, ISSN 0955-3002, E-ISSN 1362-3095, Vol. 88, no 1-2, 45-49 p.Article in journal (Refereed) Published
Abstract [en]

Purpose: To model interaction cross sections and energy loss for carbon projectiles C(0)-C(6+) of 1-10(4) keV/u (u: atomic mass unit) in water. Materials and methods: The classical trajectory Monte Carlo method was used to calculate the ionisation and charge-transfer cross sections. The excitation cross sections were scaled from proton data using equilibrium charges determined from the charge-transfer cross sections. Energy loss was obtained from the singly differential cross sections, and ionisation potentials of the target and projectile. Results: The calculated total ionisation cross sections are consistent with measured data, while the calculated electron-capture cross sections are larger than experimental data by a factor of 3. By scaling the latter to the measured data, the cross sections were made consistent with these data for 1-10 keV/u energies. The present stopping cross sections agree well with experimental data below 10 keV/u, and with other model calculations above 2 MeV/u. Deviation from the latter is found where electron capture is competitive with ionisation, and also arises from different energy-transfer calculations. Conclusions: In this paper we report our efforts in the developments of full slowing-down Monte Carlo track structure calculations for carbon ions. Further development and refinement of the model are currently underway.

Place, publisher, year, edition, pages
2012. Vol. 88, no 1-2, 45-49 p.
Keyword [en]
Carbon ions, charge transfer, interaction cross sections, CTMC, equilibrium charge, stopping cross sections
National Category
Physical Sciences
Research subject
Medical Radiation Physics
Identifiers
URN: urn:nbn:se:su:diva-81451DOI: 10.3109/09553002.2011.620061ISI: 000298666000008OAI: oai:DiVA.org:su-81451DiVA: diva2:561739
Available from: 2012-10-21 Created: 2012-10-21 Last updated: 2017-12-07Bibliographically approved
In thesis
1. Development of Monte Carlo track structure simulations for protons and carbon ions in water
Open this publication in new window or tab >>Development of Monte Carlo track structure simulations for protons and carbon ions in water
2012 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

The goal of radiation therapy is to eradicate tumour cells while minimising radiation dose to healthy tissues. Ions including protons and carbon ions have gained increasing interest for cancer treatment. Advantages of ion beam therapy are conformal dose distribution, and for ions heavier than protons increased biological effectiveness in cell killing, compared to conventional radiation therapy using photons. Despite these advantages, fundamental problems in ion beam therapy include accuracy of dose determination at the cellular level, and characterisation of the radiation quality at the microscopic scale. Due to the high density of interactions along ion tracks, inhomogeneity of dose and track parameters at the cellular level is one of the major concerns for ion beam therapy.

The aim of the thesis is to develop computational tools for dosimetry of ion tracks at the molecular level. Event-by-event Monte Carlo track structure (MCTS) simulations were developed for full-slowing-down tracks of protons and carbon ions in water representing cellular environment. In Paper I, the extension of the MCTS code KURBUC_proton was carried out to energies up to 300 MeV, covering the entire proton energy range used in radiation therapy. Physical properties and microdosimetry of proton tracks were investigated and benchmarked with the experimental data. Papers II-V describe the development of the MCTS code for full-slowing-down tracks of carbon ions. In Papers II-IV, the classical trajectory Monte Carlo (CTMC) model was developed for the calculation of interaction cross sections for low and intermediate energy carbon projectiles of all charge states (C0 to C6+) in water. In Paper V, the calculated cross sections were implemented in a new MCTS code KURBUC_carbon simulating carbon ions of energies 1-104 keV/u in water. This development allows the investigation of track parameters in the Bragg peak region of carbon ion beams.

Publication of the thesis and the published papers make contribution to the physics of ion interactions in matter, and provide a new and complete database of electronic interaction cross sections for low and intermediate energy carbon projectiles of all charge states in water. The MCTS codes for protons and carbon ions provide new tools for biophysical study, including microdosimetry, of ion tracks at cellular and subcellular levels, in particular in the Bragg peak region of these ions.

Place, publisher, year, edition, pages
Stockholm: Department of Physics, Stockholm University, 2012. 107 p.
Keyword
Radiation track structure, Monte Carlo simulations, interaction cross sections, classical trajectory Monte Carlo (CTMC) method, microdosimetry, ion beams
National Category
Physical Sciences
Research subject
Medical Radiation Physics
Identifiers
urn:nbn:se:su:diva-81461 (URN)978-91-7447-591-3 (ISBN)
Public defence
2012-11-30, Rondrum 1, Building A6, Floor 1 (A6:01), Nuclear Medicine Department, Karolinska University Hospital, Solna, 13:00 (English)
Opponent
Supervisors
Note

At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 4: Submitted. Paper 5: Submitted.

 

Available from: 2012-11-08 Created: 2012-10-21 Last updated: 2017-11-22Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text

Search in DiVA

By author/editor
Liamsuwan, Thiansin
In the same journal
International Journal of Radiation Biology
Physical Sciences

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 71 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf