Improvement of neutron spectrum unfolding based on three-group approximation using CsI self-activation method for evaluation of neutron dose around medical linacs

Ryo Kakino, Akihiro Nohtomi, Genichiro Wakabayashi

Research output: Contribution to journalArticle

Abstract

We previously evaluated ambient neutron dose equivalent by using the self-activation of a CsI scintillator around a high-energy medical linear accelerator (linac) 128I saturated activities were successfully converted to neutron spectrum and ambient neutron dose equivalent by neutron spectrum unfolding with the “three-group approximation.” The principle of the three-group approximation is based on the assumption of fixed shapes of neutron energy spectra for each of the three energy regions to evaluate the neutron spectrum effectively. However, such a neutron dose evaluation with the unfolding method might be affected by the difference between the actual fast neutron energy spectrum and the assumed spectrum. In the present work, we modified the unfolding method by taking into account the differences in the shapes of fast neutron energy spectra for various medical linacs. We verified the unfolding method using Monte Carlo simulation with several neutron spectra obtained from published research articles. The modified three-group approximation evaluates the neutron doses more accurately than the conventional unfolding method.

Original languageEnglish
Pages (from-to)40-45
Number of pages6
JournalRadiation Measurements
Volume116
DOIs
Publication statusPublished - Sep 2018

All Science Journal Classification (ASJC) codes

  • Radiation
  • Instrumentation

Fingerprint Dive into the research topics of 'Improvement of neutron spectrum unfolding based on three-group approximation using CsI self-activation method for evaluation of neutron dose around medical linacs'. Together they form a unique fingerprint.

  • Cite this