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Title: Comparisons of LET Distributions for Protons with Energies between50 and 200 MeV Determined Using a Spherical Tissue-EquivalentProportional Counter (TEPC) and a Position-Sensitive Silicon Spectrometer(RRMD-III)

Abstract

Experiments have been performed to measure the response of a spherical tissue-equivalent proportional counter (TEPC) and a silicon-based LET spectrometer (RRMD-III) to protons with energies ranging from 50 200 MeV. This represents a large portion of the energy distribution for trapped protons encountered by astronauts in low-Earth orbit. The beam energies were obtained using plastic polycarbonate degraders with a monoenergetic beam that was extracted from a proton synchrotron. The LET spectrometer provided excellent agreement with the expected LET distribution emerging from the energy degraders. The TEPC cannot measure the LET distribution directly. However, the frequency mean value of lineal energy, y bar f, provided a good approximation to LET. This is in contrast to previous results for high-energy heavy ions wherey barf underestimated LET, whereas the dose-averaged lineal energy, y barD, provided a good approximation to LET.

Authors:
; ; ; ; ; ; ; ; ; ;
Publication Date:
Research Org.:
Ernest Orlando Lawrence Berkeley NationalLaboratory, Berkeley, CA (US)
Sponsoring Org.:
USDOE Director, Office of Science; National Aeronautics andSpace Administration
OSTI Identifier:
881737
Report Number(s):
LBNL-58592
Journal ID: ISSN 0033-7587; RAREAE; R&D Project: 43GU01; BnR: 400409900; TRN: US0602990
DOE Contract Number:
DE-AC02-05CH11231; NASA:L14230C,6450938
Resource Type:
Journal Article
Resource Relation:
Journal Name: Radiation Research; Journal Volume: 162; Journal Issue: 6; Related Information: Journal Publication Date: December2004
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; 61 RADIATION PROTECTION AND DOSIMETRY; 74 ATOMIC AND MOLECULAR PHYSICS; ASTRONAUTS; DISTRIBUTION; ENERGY SPECTRA; HEAVY IONS; PLASTICS; POLYCARBONATES; PROPORTIONAL COUNTERS; PROTONS; SILICON; SPECTROMETERS; TRAPPED PROTONS; LET TEPC RRMD

Citation Formats

Borak, Thomas B., Doke, Tadayoshi, Fuse, T., Guetersloh, StephenB., Heilbronn, Lawrence H., Hara, K., Moyers, Michael, Suzuki, S., Taddei, Phillip, Terasawa, K., and Zeitlin, Cary J. Comparisons of LET Distributions for Protons with Energies between50 and 200 MeV Determined Using a Spherical Tissue-EquivalentProportional Counter (TEPC) and a Position-Sensitive Silicon Spectrometer(RRMD-III). United States: N. p., 2004. Web. doi:10.1667/RR3262.
Borak, Thomas B., Doke, Tadayoshi, Fuse, T., Guetersloh, StephenB., Heilbronn, Lawrence H., Hara, K., Moyers, Michael, Suzuki, S., Taddei, Phillip, Terasawa, K., & Zeitlin, Cary J. Comparisons of LET Distributions for Protons with Energies between50 and 200 MeV Determined Using a Spherical Tissue-EquivalentProportional Counter (TEPC) and a Position-Sensitive Silicon Spectrometer(RRMD-III). United States. doi:10.1667/RR3262.
Borak, Thomas B., Doke, Tadayoshi, Fuse, T., Guetersloh, StephenB., Heilbronn, Lawrence H., Hara, K., Moyers, Michael, Suzuki, S., Taddei, Phillip, Terasawa, K., and Zeitlin, Cary J. Wed . "Comparisons of LET Distributions for Protons with Energies between50 and 200 MeV Determined Using a Spherical Tissue-EquivalentProportional Counter (TEPC) and a Position-Sensitive Silicon Spectrometer(RRMD-III)". United States. doi:10.1667/RR3262.
@article{osti_881737,
title = {Comparisons of LET Distributions for Protons with Energies between50 and 200 MeV Determined Using a Spherical Tissue-EquivalentProportional Counter (TEPC) and a Position-Sensitive Silicon Spectrometer(RRMD-III)},
author = {Borak, Thomas B. and Doke, Tadayoshi and Fuse, T. and Guetersloh, StephenB. and Heilbronn, Lawrence H. and Hara, K. and Moyers, Michael and Suzuki, S. and Taddei, Phillip and Terasawa, K. and Zeitlin, Cary J.},
abstractNote = {Experiments have been performed to measure the response of a spherical tissue-equivalent proportional counter (TEPC) and a silicon-based LET spectrometer (RRMD-III) to protons with energies ranging from 50 200 MeV. This represents a large portion of the energy distribution for trapped protons encountered by astronauts in low-Earth orbit. The beam energies were obtained using plastic polycarbonate degraders with a monoenergetic beam that was extracted from a proton synchrotron. The LET spectrometer provided excellent agreement with the expected LET distribution emerging from the energy degraders. The TEPC cannot measure the LET distribution directly. However, the frequency mean value of lineal energy, y bar f, provided a good approximation to LET. This is in contrast to previous results for high-energy heavy ions wherey barf underestimated LET, whereas the dose-averaged lineal energy, y barD, provided a good approximation to LET.},
doi = {10.1667/RR3262},
journal = {Radiation Research},
number = 6,
volume = 162,
place = {United States},
year = {Wed Dec 01 00:00:00 EST 2004},
month = {Wed Dec 01 00:00:00 EST 2004}
}