title: An improved technique for aligning the light field with the radiation fields on radiotherapy accelerators.
abstract: An improved scheme has been developed for measuring the coincidence of the light field and radiation fields of a radiotherapy accelerator. Scans of the light and radiation fields are made sequentially using a photodiode on standard field plotting apparatus. By superimposing the two plots, differences between the two fields' boundaries can be accurately determined. The technique is simple and avoids uncertainties inherent in common techniques employing film.
authors.affiliation: Varian Associates, Palo Alto, California 94303.
authors.forename: S W
authors.initials: SW
authors.lastname: Johnsen
authors.forename: R W
authors.initials: RW
authors.lastname: Hamm
mesh_terms: D006801:Humans; D010315:Particle Accelerators; D011878:Radiotherapy / Q000295:instrumentation / Q000379:methods*