title: BEAM QUALITY CORRECTION FACTORS FOR KAP METERS FOR LIGHTLY AND HEAVILY FILTERED X-RAY BEAMS.
abstract: Kerma-area product (KAP) meters have a pronounced energy dependence when measuring air KAP for lightly filtered X-ray beams (RQR). Today, it is also common with more heavily filtered beams. In this work, the energy dependence for lightly as well as heavily filtered beams (RQC) was investigated for several KAP meter models. The relative energy dependence of the readings of an external and an internal KAP meter was determined relative to an ionisation chamber, which had been calibrated at the primary standards laboratory. As a complement to the measurements, the sensitivity of a KAP meter for various X-ray beam qualities was modelled using Monte Carlo simulations of photon transport and absorption. The result showed a variation in relative energy dependence of up to 30 % for KAP meters for RQC beam qualities compared with RQR qualities. A reduced sensitivity of KAP meters for heavily filtered beams in comparison with lightly filtered ones was found, and it is important that the beam-specific radiation quality correction factors are applied to correct the registered KAP values.
authors.affiliation: Medical Radiation Physics Malmö, Department of Translational Medicine, Lund University, Skåne University Hospital Malmö, 205 02 Malmö, Sweden lars.herrnsdorf@med.lu.se.
authors.forename: L
authors.initials: L
authors.lastname: Herrnsdorf
authors.affiliation: Medical Radiation Physics Malmö, Department of Translational Medicine, Lund University, Skåne University Hospital Malmö, 205 02 Malmö, Sweden.
authors.forename: H
authors.initials: H
authors.lastname: Petersson
mesh_terms: D000465:Algorithms; D016477:Artifacts; D002138:Calibration / Q000592:standards; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005374:Filtration / Q000295:instrumentation / Q000592:standards*; D038622:Internationality; D058996:Quality Improvement / Q000592:standards*; D000072232:Radiation Dosimeters / Q000592:standards*; D011859:Radiography / Q000295:instrumentation* / Q000592:standards; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity