Measurement of the secondary neutron dose distribution from the LET spectrum of recoils using the CR-39 plastic nuclear track detector in 10 MV X-ray medical radiation fields

Toshioh Fujibuchi, Satoshi Kodaira, Fumiya Sawaguchi, Yasuyuki Abe, Satoshi Obara, Masae Yamaguchi, Hajime Kawashima, Hisashi Kitamura, Mieko Kurano, Yukio Uchihori, Nakahiro Yasuda, Yasuhiro Koguchi, Masaru Nakajima, Nozomi Kitamura, Tomoharu Sato

Research output: Contribution to journalArticle

8 Citations (Scopus)

Abstract

We measured the recoil charged particles from secondary neutrons produced by the photonuclear reaction in a water phantom from a 10-MV photon beam from medical linacs. The absorbed dose and the dose equivalent were evaluated from the linear energy transfer (LET) spectrum of recoils using the CR-39 plastic nuclear track detector (PNTD) based on well-established methods in the field of space radiation dosimetry. The contributions and spatial distributions of these in the phantom on nominal photon exposures were verified as the secondary neutron dose and neutron dose equivalent. The neutron dose equivalent normalized to the photon-absorbed dose was 0.261 mSv/100 MU at source to chamber distance 90 cm. The dose equivalent at the surface gave the highest value, and was attenuated to less than 10% at 5 cm from the surface. The dose contribution of the high LET component of ≥100 keV/μm increased with the depth in water, resulting in an increase of the quality factor. The CR-39 PNTD is a powerful tool that can be used to systematically measure secondary neutron dose distributions in a water phantom from an in-field to out-of-field high-intensity photon beam.

Original languageEnglish
Pages (from-to)239-245
Number of pages7
JournalNuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms
Volume349
DOIs
Publication statusPublished - Apr 15 2015

All Science Journal Classification (ASJC) codes

  • Nuclear and High Energy Physics
  • Instrumentation

Fingerprint Dive into the research topics of 'Measurement of the secondary neutron dose distribution from the LET spectrum of recoils using the CR-39 plastic nuclear track detector in 10 MV X-ray medical radiation fields'. Together they form a unique fingerprint.

  • Cite this