Determination of Photon Conversion Factors Relating Exposure and Dose for Several Extremity Phantom Designs

摘要

This report presents the results of measurements of dosimetric properties of simple extremity phantoms suitable for use in extremity dosimeter performance testing. Two sizes of phantoms were used in this study. One size represented the forearm or lower leg and the other size represented the finger or toe. For both phantom sizes, measurements were performed on solid plastic phantoms and on phantoms containing simulated bone material to determine the effect of backscattered radiations from the bone on the surface dose. Exposure-to-dose conversion factors (C/sub x/ factors) were determined for photon energies ranging from 16 to 1250 keV (average for sup 60 Co). The effect of the presence of a phantom was also measured for a sup 90 Sr/ sup 90 Y source. Significant differences in the measured C/sub x/ factors were found among the phantoms investigated. The factors for the finger-sized phantoms were uniformly less than for the arm-sized phantoms. (ERA citation 12:002559)