title: Spectral fluence of neutrons generated by radiotherapeutic linacs.
abstract: Spectral fluences of neutrons generated in the heads of the radiotherapeutic linacs Varian Clinac 2100 C/D and Siemens ARTISTE were measured by means of the Bonner spheres spectrometer whose active detector of thermal neutrons was replaced by an activation detector, i.e. a tablet made of pure manganese. Measurements with different collimator settings reveal an interesting dependence of neutron fluence on the area defined by the collimator jaws. The determined neutron spectral fluences were used to derive ambient dose equivalent rate along the treatment coach. To clarify at which components of the linac neutrons are mainly created, the measurements were complemented with MCNPX calculations based on a realistic model of the Varian Clinac.
authors.affiliation: Czech Metrology Institute, Prague 10 CZ-102 00, Czech Republic mkralik@cmi.cz.
authors.forename: Miloslav
authors.initials: M
authors.lastname: Králík
authors.affiliation: Czech Metrology Institute, Prague 10 CZ-102 00, Czech Republic.
authors.forename: Jaroslav
authors.initials: J
authors.lastname: Šolc
authors.affiliation: Proton Therapy Center, Budínova 2, Prague 8 CZ-180 00, Czech Republic.
authors.forename: Vladimir
authors.initials: V
authors.lastname: Vondráček
authors.affiliation: Czech Metrology Institute, Prague 10 CZ-102 00, Czech Republic.
authors.forename: Jana
authors.initials: J
authors.lastname: Šmoldasová
authors.affiliation: Thomayer's Hospital, Vídeňská 80, Prague 4 CZ-140 59, Czech Republic.
authors.forename: Estera
authors.initials: E
authors.lastname: Farkašová
authors.affiliation: Thomayer's Hospital, Vídeňská 80, Prague 4 CZ-140 59, Czech Republic.
authors.forename: Ivana
authors.initials: I
authors.lastname: Tichá
mesh_terms: D003198:Computer Simulation; D017076:Computer-Aided Design; D004867:Equipment Design; D019544:Equipment Failure Analysis; D015233:Models, Statistical; D009010:Monte Carlo Method; D009502:Neutrons; D010315:Particle Accelerators / Q000295:instrumentation*; D011829:Radiation Dosage; D011874:Radiometry / Q000295:instrumentation* / Q000379:methods*; D016634:Radiosurgery / Q000295:instrumentation*; D012542:Scattering, Radiation