Dosimetric and microdosimetric characteristics of high energy proton beams

Citation
F. Spurny et al., Dosimetric and microdosimetric characteristics of high energy proton beams, RADIAT MEAS, 34(1-6), 2001, pp. 527-531
Citations number
12
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science
Journal title
RADIATION MEASUREMENTS
ISSN journal
13504487 → ACNP
Volume
34
Issue
1-6
Year of publication
2001
Pages
527 - 531
Database
ISI
SICI code
1350-4487(200106)34:1-6<527:DAMCOH>2.0.ZU;2-S
Abstract
High energy (greater than or equal to 50 MeV) protons can be considered, wh en their ionization losses stopping power is taken into account, as the rad iation with low (< 5 keV/mum) linear energy transfer (LET). However, their energy is already sufficient to create, through the nuclear reactions in ir radiated matter, secondary particles with much higher LET. This phenomenon can modify the characteristics of the energy transfer process due to these particles, which should be taken into account when such particles are used for radiobiology studies and/or for radiotherapy. The importance of these secondary particles was studied experimentally by m eans of the LET spectrometer based on a chemically etched track detector, i n which the tracks of primary protons are not revealed. The studies were pe rformed in proton beams available at the Joint Institute of Nuclear Researc h (JINR) at Dubna, Russia, with protons of primary energies of about 200 Me V and 1 GeV. The microdosimetric distribution of secondary particles mentio ned are presented and compared and their contribution to primary proton ion ization losses absorbed dose is estimated. This contribution increases rela tively with the proton energy, and also changes with the depth of penetrate d material. The importance of this phenomenon to some applications is discu ssed. (C) 2001 Elsevier Science Ltd. All rights reserved.