title: MCNP simulation of a Theratron 780 radiotherapy unit.
abstract: A Theratron 780 (MDS Nordion) 60Co radiotherapy unit has been simulated with the Monte Carlo code MCNP. The unit has been realistically modelled: the cylindrical source capsule and its housing, the rectangular collimator system, both the primary and secondary jaws and the air gaps between the components. Different collimator openings, ranging from 5 x 5 cm2 to 20 x 20 cm2 (narrow and broad beams) at a source-surface distance equal to 80 cm have been used during the study. In the present work, we have calculated spectra as a function of field size. A study of the variation of the electron contamination of the 60Co beam has also been performed.
authors.affiliation: Departamento de Ingeniería Química y Nuclear, Universidad Politécnica de València, Camí de Vera, s/n, 46022 València, Spain. rmiro@iqn.upv.es
authors.forename: R
authors.initials: R
authors.lastname: Miró
authors.forename: J
authors.initials: J
authors.lastname: Soler
authors.forename: S
authors.initials: S
authors.lastname: Gallardo
authors.forename: J M
authors.initials: JM
authors.lastname: Campayo
authors.forename: S
authors.initials: S
authors.lastname: Díez
authors.forename: G
authors.initials: G
authors.lastname: Verdú
mesh_terms: D000465:Algorithms; D003037:Cobalt Radioisotopes / Q000032:analysis*; D003198:Computer Simulation; D019544:Equipment Failure Analysis; D015233:Models, Statistical; D009010:Monte Carlo Method; D011835:Radiation Protection / Q000379:methods*; D011874:Radiometry / Q000379:methods*; D011878:Radiotherapy / Q000295:instrumentation*; D011879:Radiotherapy Dosage
chemical_list: D003037:Cobalt Radioisotopes