TY - JOUR
T1 - The response of a spherical tissue-equivalent proportional counter to different heavy ions having similar velocities
AU - Taddei, Phillip J.
AU - Borak, Thomas B.
AU - Guetersloh, Stephen B.
AU - Gersey, Brad B.
AU - Zeitlin, Cary
AU - Heilbronn, Lawrence
AU - Miller, Jack
AU - Murakami, Takeshi
AU - Iwata, Yoshiyuki
N1 - Funding Information:
This research was supported primarily by the NASA Specialized Centers for Outreach, Research, and Training in Radiation Health. Support was also provided through the Japanese Society for the Promotion of Sciences short-term fellowship program. We wish to thank the staff of the Heavy Ion Medical Accelerator (HIMAC) at the National Institute of Radiological Sciences (NIRS) in Chiba, Japan for providing valuable beam time and support.
PY - 2006/10
Y1 - 2006/10
N2 - A tissue-equivalent proportional counter (TEPC) has been used as a dosimeter in mixed radiation fields. Since it does not measure LET directly, the response function must be characterized in order to estimate quality factor and thus equivalent dose for the incident radiation. The objectives of this study were to measure the response of a spherical TEPC for different high-energy heavy ions (HZE) having similar velocity and to determine how quality factors can be determined. Data were obtained at the HIMAC heavy ion accelerator for 4He and 12C at 220 ± 5 MeV / nucleon(β = 0.59) and 12C, 16O, 28Si and 56Fe at 376 ± 15 MeV / nucleon(β = 0.70) . A particle spectrometer recorded the charge and position of each incident beam particle. Events with low energy deposition were observed for particles that passed through the wall of the TEPC but not through the sensitive volume. The frequency averaged lineal energy, over(y, -)f, was always less than the LET of the incident particles. The dose averaged lineal energy, over(y, -)D, was approximately equal to LET for particles with LET greater than 10 keV/μm, whereas over(y, -)D was larger than LET for the lighter particles with lower LET. Part of this effect is due to detector resolution and energy straggling that increases the variance of the response function. Although the TEPC is not a LET spectrometer, it can provide real time measurements of dose and provide estimates of quality factors for HZE particles using averaged values of lineal energy.
AB - A tissue-equivalent proportional counter (TEPC) has been used as a dosimeter in mixed radiation fields. Since it does not measure LET directly, the response function must be characterized in order to estimate quality factor and thus equivalent dose for the incident radiation. The objectives of this study were to measure the response of a spherical TEPC for different high-energy heavy ions (HZE) having similar velocity and to determine how quality factors can be determined. Data were obtained at the HIMAC heavy ion accelerator for 4He and 12C at 220 ± 5 MeV / nucleon(β = 0.59) and 12C, 16O, 28Si and 56Fe at 376 ± 15 MeV / nucleon(β = 0.70) . A particle spectrometer recorded the charge and position of each incident beam particle. Events with low energy deposition were observed for particles that passed through the wall of the TEPC but not through the sensitive volume. The frequency averaged lineal energy, over(y, -)f, was always less than the LET of the incident particles. The dose averaged lineal energy, over(y, -)D, was approximately equal to LET for particles with LET greater than 10 keV/μm, whereas over(y, -)D was larger than LET for the lighter particles with lower LET. Part of this effect is due to detector resolution and energy straggling that increases the variance of the response function. Although the TEPC is not a LET spectrometer, it can provide real time measurements of dose and provide estimates of quality factors for HZE particles using averaged values of lineal energy.
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U2 - 10.1016/j.radmeas.2006.01.003
DO - 10.1016/j.radmeas.2006.01.003
M3 - Article
C2 - 19079798
AN - SCOPUS:33751249920
SN - 1350-4487
VL - 41
SP - 1227
EP - 1234
JO - Radiation Measurements
JF - Radiation Measurements
IS - 9-10
ER -