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
