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| Comparation on the Absorbed Dose to Water in 398/277 Report for Linac's High Energy Photon Beams in Beijing District |
| LUO Chen1,FAN Yao-dong1,WANG Kun2,WANG Huan-ning1,LU Xiang1,ZHAO Gui-kun1 |
1. Beijing Institute of Metrology, Beijing 100029, China
2. National Institute of Metrology, Beijing 100029, China |
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Abstract In view of the absorbed dose to water measurement method in China is about to be updated, more than 200 value verification experiment in high-energy photon beams have been carried out under the medical accelerators of the radiation department in several hospitals in Beijing. According to the measurement methods reported by IAEA 277 and IAEA 398, the dose values at the maximum dose point of high-energy photons were measured and compared. In the NE2571 ionization chamber, the result measured by 398 report was 0.23% higher than that by 277 report, and this ratio was 0.85% in the PTW30013 ionization chamber. The experiment showed that the measurement results of the two methods were consistent within the uncertainty range, and the experiment established the experimental basis for the implementation of the 398 value system in China. The deviation of the results was analyzed, the calculation process of the correlation factors was studied , and the causes of the deviation were discussed from the perspective of several correction factors.
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Received: 12 October 2019
Published: 19 January 2021
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2021, Vol. 42 
