WATER CALORIMETRY FOR RADIATION-DOSIMETRY

Calorimetry has a long history as a technique for establishing the abs orbed dose, and graphite calorimetry has often been used to establish absorbed dose standards for use in radiation therapy. However, a conve rsion process is necessary to convert from dose to graphite to dose to water, which is the quantity of clinical interest. In order to more d irectly measure the dose to water, considerable effort has been devote d in the last fifteen years to the development of water calorimetry. T his article reviews these developments and summarizes the present stat us of water calorimetry. Absorbed dose standards based on water calori metry and with a relative standard uncertainty of 0.5-1% now seem achi evable.