title: Neutron measurements with ultra-thin 3D silicon sensors in a radiotherapy treatment room using a Siemens PRIMUS linac.
abstract: The accurate detection and dosimetry of neutrons in mixed and pulsed radiation fields is a demanding instrumental issue with great interest both for the industrial and medical communities. In recent studies of neutron contamination around medical linacs, there is a growing concern about the secondary cancer risk for radiotherapy patients undergoing treatment in photon modalities at energies greater than 6 MV. In this work we present a promising alternative to standard detectors with an active method to measure neutrons around a medical linac using a novel ultra-thin silicon detector with 3D electrodes adapted for neutron detection. The active volume of this planar device is only 10 µm thick, allowing a high gamma rejection, which is necessary to discriminate the neutron signal in the radiotherapy peripheral radiation field with a high gamma background. Different tests have been performed in a clinical facility using a Siemens PRIMUS linac at 6 and 15 MV. The results show a good thermal neutron detection efficiency around 2% and a high gamma rejection factor.
authors.affiliation: Instituto de Microelectrónica de Barcelona (IMB-CNM, CSIC), E-08193 Bellaterra, Barcelona, Spain. Consuelo.Guardiola@imb-cnm.csic.es
authors.forename: C
authors.initials: C
authors.lastname: Guardiola
authors.forename: F
authors.initials: F
authors.lastname: Gómez
authors.forename: C
authors.initials: C
authors.lastname: Fleta
authors.forename: J
authors.initials: J
authors.lastname: Rodríguez
authors.forename: D
authors.initials: D
authors.lastname: Quirion
authors.forename: G
authors.initials: G
authors.lastname: Pellegrini
authors.forename: A
authors.initials: A
authors.lastname: Lousa
authors.forename: L
authors.initials: L
authors.lastname: Martínez-de-Olcoz
authors.forename: M
authors.initials: M
authors.lastname: Pombar
authors.forename: M
authors.initials: M
authors.lastname: Lozano
mesh_terms: D001895:Boron / Q000737:chemistry; D005720:Gamma Rays; D007554:Isotopes; D009010:Monte Carlo Method; D009502:Neutrons / Q000627:therapeutic use*; D011874:Radiometry; D011881:Radiotherapy, Computer-Assisted / Q000295:instrumentation / Q000379:methods*; D012825:Silicon / Q000737:chemistry*
chemical_list: D007554:Isotopes; D001895:Boron; D012825:Silicon