title: 137Cs Dosimeter Irradiation Facilities: Calibration Frequency, Precision, and Accuracy.
abstract: Many dosimeter and instrument calibration sources, especially Cs irradiators permanently installed in facilities, are infrequently calibrated since their geometry is not subject to large variation, their mechanisms are simple, and their operation can be visibly error-free for decades. Only decay corrections are needed to know delivered doses at fixed locations once a thorough characterization of such facilities is completed. For one such Cs source, however, collected current values in a span of a few days were found to drop significantly. Malfunction of the internal positioning mechanisms through wear were found to be the cause. This paper suggests periodic source calibrations for the timely identification of source failures that could cause gross errors in dose delivery. In addition, a rigorous analysis of the magnitude of uncertainties and errors in dose delivery using a calibration source is included, which is based upon newly collected experimental data. This provides a technical basis for calibration procedures to ensure a given accuracy and precision of dose delivery.
authors.affiliation: *University of Michigan, Department of Nuclear Engineering and Radiological Sciences, Ann Arbor MI 48109-2104.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Boria
authors.forename: Blake D
authors.initials: BD
authors.lastname: Rucinski
authors.forename: Sara A
authors.initials: SA
authors.lastname: Abraham
authors.forename: Alexander S
authors.initials: AS
authors.lastname: Dawson
authors.forename: Ali H
authors.initials: AH
authors.lastname: Jawad
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Miklos
authors.forename: Kimberlee J
authors.initials: KJ
authors.lastname: Kearfott
mesh_terms: D002138:Calibration / Q000592:standards*; D002588:Cesium Radioisotopes / Q000032:analysis* / Q000592:standards*; D004307:Dose-Response Relationship, Radiation; D004867:Equipment Design; D019544:Equipment Failure Analysis / Q000379:methods / Q000592:standards; D005160:Facility Design and Construction / Q000592:standards*; D008824:Michigan; D011829:Radiation Dosage; D011874:Radiometry / Q000295:instrumentation* / Q000592:standards*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D002588:Cesium Radioisotopes