title: Dose rate outside primary barriers.
abstract: The author has investigated the use of the inverse square function to predict the photon dose rate outside primary barriers for medical accelerators. Measurements of the dose rate as a function of distance outside the barriers were made at five medical accelerator facilities. An analysis of the data showed that the radiation field appears to diverge from a point between the x-ray target and primary barrier. This behavior of the x-ray beam was attributed to scattering of photons in the shield barrier. It was concluded that the dose outside the barrier will be overestimated if the distance from the x-ray target to the point of calculation is utilized to carry out an inverse square correction.
authors.affiliation: Emory Clinic, Department of Radiation Oncology, 1365 Clifton Road, Atlanta, GA 30322, USA. patton@radonc.emory.org
authors.forename: P H
authors.initials: PH
authors.lastname: McGinley
mesh_terms: D006283:Health Physics; D006801:Humans; D010315:Particle Accelerators / Q000295:instrumentation; D017785:Photons; D011829:Radiation Dosage; D011835:Radiation Protection / Q000295:instrumentation; D012542:Scattering, Radiation; D014965:X-Rays