XI CPAN DAYS

Time resolved out-of-field secondary neutron dose measurements in pencil beam scanning (PBS) proton therapy

21 oct. 2019 18:10

20m

Investigación orientada, tecnología e innovación Investigación orientada, tecnología e innovación

Abstract

Experimental studies on the secondary out-of-field neutron dose at the West German Proton Therapy Centre Essen (WPE) are presented. The neutron ambient dose equivalent, Hn (10), was studied in pencil beam scanning mode (PBS) through the use of two lightweight dosimeters prototypes (LINrem detectors) recently developed by the Experimental Nuclear Physics group at INTE-UPC. A non-extended survey (LINrem1) is able to provide estimations of Hn(10) in the
energy range up to the evaporation peak (En ~10 MeV). The total Hn(10) was measured by an extended dosimeter (LINremext1) especially optimized for proton therapy applications. This detector includes a lead converter, thus providing sensitivity up to GeV. LINrem detectors are fully
integrated into a digital acquisition system, thus providing temporal resolution, sorting capabilities and correlation analysis. Temporally resolved measurements of the secondary stray neutron field are presented. The contribution from neutrons with En>10 MeV to the total H n (10) has been
investigated by combining both dosimeters. The comparison of LINrem measurements with the an EURADOS intercomparison exercise in PBS is presented.