title: The response of a spherical tissue-equivalent proportional counter to different ions having similar linear energy transfer.
abstract: The response of a tissue-equivalent proportional counter (TEPC) to different ions having a similar linear energy transfer (LET) has been studied. Three ions, 14N, 20Ne and 28Si, were investigated using the HIMAC accelerator at the National Institute of Radiological Sciences at Chiba, Japan. The calculated linear energy transfer (LET( infinity )) of all ions was 44 +/- 2 keV/microm at the sensitive volume of the TEPC. A particle spectrometer was used to record the charge and position of each incident beam particle. This enabled reconstruction of the location of the track as it passed though the TEPC and ensured that the particle survived without fragmentation. The spectrum of energy deposition events in the TEPC could be evaluated as a function of trajectory through the TEPC. The data indicated that there are many events from particles that did not pass through the sensitive volume. The fraction of these events increased as the energy of the particle increased due to changes in the maximum energy of the delta rays. Even though the LET of the incident particles was nearly identical, the frequency-averaged lineal energy, y(F), as well as the dose-averaged lineal energy, y(D), varied with the velocity of the incident particle. However, both values were within 15% of LET in all cases.
authors.affiliation: Department of Radiological Health Sciences, Colorado State University, Fort Collins, Colorado 80523, USA.
authors.forename: Stephen B
authors.initials: SB
authors.lastname: Guetersloh
authors.forename: Thomas B
authors.initials: TB
authors.lastname: Borak
authors.forename: Phillip J
authors.initials: PJ
authors.lastname: Taddei
authors.forename: Cary
authors.initials: C
authors.lastname: Zeitlin
authors.forename: Lawrence
authors.initials: L
authors.lastname: Heilbronn
authors.forename: Jack
authors.initials: J
authors.lastname: Miller
authors.forename: Takeshi
authors.initials: T
authors.lastname: Murakami
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Iwata
mesh_terms: D003198:Computer Simulation; D003238:Connective Tissue / Q000528:radiation effects*; D020450:Heavy Ions; D007554:Isotopes / Q000032:analysis*; D018499:Linear Energy Transfer / Q000502:physiology*; D008954:Models, Biological; D009356:Neon / Q000032:analysis; D009587:Nitrogen Isotopes / Q000032:analysis; D011829:Radiation Dosage; D011835:Radiation Protection / Q000379:methods*; D011874:Radiometry / Q000295:instrumentation* / Q000379:methods*; D012062:Relative Biological Effectiveness; D015203:Reproducibility of Results; D012542:Scattering, Radiation; D012680:Sensitivity and Specificity; D012825:Silicon / Q000032:analysis
chemical_list: D007554:Isotopes; D009587:Nitrogen Isotopes; D009356:Neon; D012825:Silicon