Photon Spectra calculation for an Elekta linac beam using experimental scatter measurements and Monte Carlo techniques.

Author

Juste, B. ; Miró, R. ; Campayo, J.M. ; Díez, S. ; Verdú, G.

Author_Institution

Chemical and Nuclear Engineering Department at the Polytechnic University of Valencia, CamÃ\xad de Vera s/n 46022, Spain

fYear

2008

fDate

20-25 Aug. 2008

Firstpage

3289

Lastpage

3292

Abstract

The present work is centered in reconstructing by means of a scatter analysis method the primary beam photon spectrum of a linear accelerator. This technique is based on irradiating the isocenter of a rectangular block made of methacrylate placed at 100 cm distance from surface and measuring scattered particles around the plastic at several specific positions with different scatter angles. The MCNP5 Monte Carlo code has been used to simulate the particles transport of mono-energetic beams to register the scatter measurement after contact the attenuator. Measured ionization values allow calculating the spectrum as the sum of mono-energetic individual energy bins using the Schiff Bremsstrahlung model. The measurements have been made in an Elekta Precise linac using a 6 MeV photon beam. Relative depth and profile dose curves calculated in a water phantom using the reconstructed spectrum agree with experimentally measured dose data to within 3%.

Keywords

Electromagnetic scattering; Linear accelerators; Linear particle accelerator; Monte Carlo methods; Particle beam measurements; Particle beams; Particle measurements; Particle scattering; Position measurement; Surface reconstruction; Algorithms; Computer Simulation; Equipment Design; Humans; Ions; Models, Statistical; Monte Carlo Method; Particle Accelerators; Photons; Radiometry; Radiotherapy Dosage; Radiotherapy Planning, Computer-Assisted; Reproducibility of Results; Scattering, Radiation; Spectrum Analysis;

fLanguage

English

Publisher

ieee

Conference_Titel

Engineering in Medicine and Biology Society, 2008. EMBS 2008. 30th Annual International Conference of the IEEE

Conference_Location

Vancouver, BC

ISSN

1557-170X

Print_ISBN

978-1-4244-1814-5

Electronic_ISBN

1557-170X

Type

conf

DOI

10.1109/IEMBS.2008.4649907

Filename

4649907