title: Physical characterization of a 137Cs field used for proficiency-test irradiations.
abstract: This paper describes a series of measurements and calculations that were undertaken at the Pacific Northwest Laboratory to determine the physical and dosimetric characteristics of a 137Cs source, which is housed within a commercially manufactured irradiator. These measurements and calculations helped to demonstrate that: (1) the exposure rate for this source was consistent with (traceable to) radiation standards maintained by the National Institute of Standards and Technology; (2) the radiation field at the surface of the irradiation phantom, in a 10 cm X 10 cm central area, was uniform to within +/- 2%; (3) the contribution of scattered photons was minimal; and (4) the ratio of the shallow to the deep dose equivalent was nearly unity. Because there are a number of similar irradiators in use, it is hoped that the methodology and results described in this paper will be of use to others.
authors.affiliation: Pacific Northwest Laboratory, Richland, WA 99352.
authors.forename: M K
authors.initials: MK
authors.lastname: Murphy
authors.forename: R J
authors.initials: RJ
authors.lastname: Traub
authors.forename: J C
authors.initials: JC
authors.lastname: McDonald
authors.forename: C D
authors.initials: CD
authors.lastname: Hooker
mesh_terms: D002588:Cesium Radioisotopes; D011829:Radiation Dosage; D011874:Radiometry
chemical_list: D002588:Cesium Radioisotopes