Analysis of photoneutron spectra produced in medical accelerators.
A complete method is presented for the evaluation of photoneutron spectra produced in linear accelerators for cancer radiotherapy. It consists of a computer simulation code based on the MCNP4B Monte Carlo code, in which the new routine GAMMAN was implemented, allowing the accurate study of photoneutron production in high Z elements. In addition an experimental method based on a passive bubble spectrometer allows direct measurements of the photoneutron spectrum at the patient plane, also under the photon beam. The results are presented both for a 15 MeV linac with a traditional collimator system and for an 18 MeV linac equipped with a multileaf collimator, used in conformational radiotherapy.
Ongaro
C
C
Dipartimento di Fisica Sperimentale, Università di Torino, Italy. ongaro@to.infn.it
Zanini
A
A
Nastasi
U
U
Ródenas
J
J
Ottaviano
G
G
Manfredotti
C
C
Burn
K W
KW
D003198:Computer Simulation; D009010:Monte Carlo Method; D009502:Neutrons; D010315:Particle Accelerators; D017785:Photons; D011874:Radiometry / Q000379:methods; D020266:Radiotherapy, Conformal / Q000295:instrumentation; D012984:Software; D013057:Spectrum Analysis