| Abstract: | 本論文旨在探討本實驗室與行政院原子能委員會核能研究所共同開發之「石墨卡計原級標準系統」的量測不確定度來源及其修正因子。延續前期學長論文「石墨卡計原級標準系統量測不確定度評估之研究」的研究成果，本論文將該石墨卡計實際執行Co-60照射實驗，並針對所擷取之實驗數據進行其量測不確定度分析及修正因子校正，期能使該石墨卡計量測數據與核能研究所現有水吸收計量標準之差異小於1%，以達國家原級標準之需求。根據現階段之石墨卡計版本所取得之實驗數據分析，在未進行修正因子校正前，該石墨卡計量測數據與現有水吸收劑量標準之差異為3.028%，符合103年度執行計畫小於5%之預期目標。經本論文進行真空間隙、核心雜質、軸向不均勻、徑向不均勻、熱缺陷、水吸收劑量除以石墨吸收劑量及導線散熱等修正因子校正後，其量測數據與現有水吸收劑量標準之差異已降為1.541845%，已十分接近本年度執行計畫小於1%之預期目標。
The main aim of this thesis is to investigate the sources of measurement uncertainty and the correction factors of the primary standard graphite calorimeter, which is co-developed by Institute of Nuclear Energy Research, Atomic Energy Council, Executive Yuan and our research lab. To extend the research works of previous thesis entitled “A study on the estimation of measurement uncertainty of primary standard graphite calorimeter system”, we perform the experiment about Co-60 absorbed dose by the primary standard graphite calorimeter, analyze the measurement uncertainty of the experiment data, and then calibrate the measurement dose rate with some correction factors. It is expected that the difference between the calibrated measurement data and the current standard of absorbed dose by water would be less than 1% so that the graphite calorimeter could meet the requirement of national primary standard.According to the analyses of the measurement data obtained from the current graphite calorimeter version, the difference between the original measurement data and the current standard of absorbed dose by water is 3.028%. The result has met the expected aim, with difference less than 5%, of the project performed by 2014. In this thesis, we further calibrate the measurement data with the correction factors, including vacuum gaps,core impurity, axial nonuniformity, radial nonuniformity, heat defect, conversion from graphite to water, and power consumption on the leading wires. The difference between the calibrated measurement data and the current standard of absorbed dose by water has reduced to be 1.5418%. Obviously, it approaches to the expected aim, with difference less than 1%, of the project performed by this year. |
