Objective Measuring the field dose rate of cobalt-60 therapy unit to obtain the current dose rate and analyse the uniformity, including flatness and symmetry, of the dose distribution. Then the data can be used as guidance in tumor radiation therapy and radiation medical experiment. Methods U-sing thimble chamber to measure dose rate of radiation field(20 cm ×20 cm) at 80cm of source skin distance, including Cross-Plane and In-Plane direction, and analyse the flatness and symmetry. Results Five current mean dose rates of five square fields were obtained as user' s reference data. According to the tolerant deviation ( ±3% ) , the analysis results showed that the deviation accorded with the criterion basically. Conclusion It can be thought that,the dose distribution of radiation field is uniform. It has little influence on tumor therapy or radiation medical experiment.
NETL
NSTL
维普
万方数据
