Title: Comparison of the NPL water calorimeter with other dosimetric techniques for high energy photon beams.
Abstract: At present, the primary standard of absorbed dose to water at NPL in high energy photon beams is a graphite calorimeter. However the quantity of interest in radiation dosimetry is absorbed dose to water. Therefore, a new absorbed dose to water standard based on water calorimetry is being developed at NPL. The calorimeter operates at 4 DC, with temperature control being provided by a combination of liquid and air cooling. The sealed glass inner vessel of the calorimeter has been designed to minimise the effect of non-water materials on the measurement of absorbed dose. Measurements of absorbed dose to water made in 6, 10 and 19 MV photon beams agreed within the measurement uncertainties with those determined using the primary standard graphite calorimeter. Also the absorbed dose to water measured using the water calorimeter agrees with that based on the air kerma standards for 6OCO y-radiation within the uncertainties. The development of the water calorimeter will lead to a very robust dosimetry system at NPL, where the absorbed dose to water can be determined using three independent techniques.
Publication Year: 1999
Publication Date: 1999-03-01
Language: en
Type: article
Access and Citation
AI Researcher Chatbot
Get quick answers to your questions about the article from our AI researcher chatbot