title: A study on virtual source position for electron beams from a Mevatron MD linear accelerator.
abstract: The virtual source position (VSP) for electron beams of energies 5, 7, 9 10, 12 and 14 MeV and for the applicators (cones) available in the department have been measured for a Mevatron MD class linear accelerator. Different methods of obtaining the virtual source position for electron beams have been investigated in the present study. The results obtained have been compared with those of other workers. It is observed that the VSP is very much machine dependent and needs to be measured for each linear accelerator. The effect of shielding on virtual source position for the type of applicators available in the department has also been investigated.
authors.affiliation: Department of Radiation Oncology, Christian Medical College and Hospital, Vellore, India. paul@cmcvellore.ac.in
authors.forename: B P
authors.initials: BP
authors.lastname: Ravindran
mesh_terms: D000388:Air; D055592:Biophysical Phenomena; D001703:Biophysics; D004583:Electrons; D006801:Humans; D009369:Neoplasms / Q000532:radiotherapy; D010315:Particle Accelerators / Q000295:instrumentation*; D011880:Radiotherapy Planning, Computer-Assisted / Q000706:statistics & numerical data; D011882:Radiotherapy, High-Energy / Q000295:instrumentation*