tailieunhanh - Building a graphite calorimetry system for the dosimetry of therapeutic X-ray beams

The noise level of the temperature measurement system was approximately mK (peak to peak). The temperature of the core part rose by approximately mK at 800 MU (monitor unit) for 6-MV Xray beams, and it increased as X-ray energy increased. The temperature rise showed less spread when it was normalized to the accumulated charge, as measured by an external monitoring chamber. | Building a graphite calorimetry system for the dosimetry of therapeutic X-ray beams N u c l e a r E n g i n e e r i n g a n d T e c h n o l o g y 4 9 ( 2 0 1 7 ) 8 1 0 e8 1 6 Available online at ScienceDirect Nuclear Engineering and Technology journal homepage: Original Article Building a Graphite Calorimetry System for the Dosimetry of Therapeutic X-ray Beams In Jung Kim*, Byoung Chul Kim, Joong Hyun Kim, Jae-Pil Chung, Hyun Moon Kim, and Chul-Young Yi Korea Research Institute of Standards and Science, 267 Gajeong-ro, Yuseong-gu, Daejeon 34113, Republic of Korea article info abstract Article history: A graphite calorimetry system was built and tested under irradiation. The noise level of the Received 11 November 2016 temperature measurement system was approximately mK (peak to peak). The tem- Accepted 5 January 2017 perature of the core part rose by approximately mK at 800 MU (monitor unit) for 6-MV X- Available online 11 February 2017 ray beams, and it increased as X-ray energy increased. The temperature rise showed less spread when it was normalized to the accumulated charge, as measured by an external Keywords: monitoring chamber. The radiation energy absorbed by the core part was determined to High Energy X-ray have values of J/mC, J/mC, and J/mC at 6 MV, 10 MV, and 18 MV, respectively. Absorbed Dose These values were so consistent among repeated runs that their coefficient of variance was Graphite Calorimeter less than . Calorimetry © 2017 Korean Nuclear Society, Published by Elsevier Korea LLC. This is an open access article under the CC BY-NC-ND license ( ). 1. Introduction The radiation therapy dose is calibrated in terms of the water absorbed dose (unit: Gy) [4e6]. The water absorbed dose Radiation therapy using high energy X-rays generated by is a physical quantity that is defined as