近年來國內有質子治療設施的興建，因此需要關切高能質子射束的輻射防護議題，當病人選擇質子治療採用被動式射束散射系統時通常會使用病人專屬黃銅塊（以下簡稱：黃銅塊）作為質子射束照野的塑型，黃銅塊主要目的是用來阻擋腫瘤形狀以外質子，故需要探討黃銅塊被質子照射後活化的情形對病人與工作人員的影響。
活化的黃銅塊中會產生放射性核種，故在不同時間點接觸到活化的黃銅塊則會受到不同放射性核種的曝露，在病人治療前後工作人員會協助病人裝上與卸下黃銅塊，故工作人員的手部會接觸黃銅塊而有手部劑量的疑慮，另一個時間點是病人的治療療程結束後會將黃銅塊外釋，故評估外釋前需要暫存的時間是重要的議題。
本研究使用高純度鍺偵檢器來量測活化的黃銅塊中放射性核種與放射性核種的活度並與FLUKA計算活度結果比較，關於以實驗的方式量化活化的黃銅塊中放射性核種的活度，首先需要得到該樣品對於高純度鍺偵檢器的偵測效率曲線，在本研究中先探討高純度鍺偵檢器對於點射源的全能峰效率曲線，將實驗與MCNP6計算的結果比較，進一步以MCNP6計算活化的黃銅塊其全能峰效率曲線，以該方法評估放射性核種於活化的黃銅塊中之活度，下一步將臨床上常見的治療流程（20次治療共四週）透過FLUKA來計算黃銅塊在被質子射束照射下活化的情形，以計算出放射性核種於黃銅塊中的劑量率以估算工作人員的手部劑量，關於計算得到的放射性核種的活度大小則用來評估外釋前暫存所需要的時間。
高純度鍺偵檢器實驗與計算的全能峰效率曲線於5公分、10公分和20公分三個位置下的差異為0.92～1.14，因此以MCNP6建立出高純度鍺偵檢器的模型用來評估出不同射源幾何狀況的全能峰效率曲線。關於活化的黃銅塊冷卻一小時、九天和三個月時間點量測到的放射性核種與FLUKA計算的結果大致上一致，針對放射性核種活度的比較，對活化的黃銅塊冷卻三個月FLUKA計算的活度高估2～6倍，因為放射性核種於黃銅塊中的分佈不均勻為主要因素，故依據臨床條件所評估出來的工作人員手部劑量與放射性廢棄物外釋所需要的時間是相對保守。本研究所評估出來工作人員的手部劑量為4.96 mSv/y，活化的黃銅塊需要暫時保存至少六個月後才可以外釋。

In recent years, several proton therapy facilities is being built in Taiwan. We concern the radiation protection issues of the high energy proton beam. When proton therapy with passive beam scattering system is adopted, a patient-specific brass aperture is needed to conform the irradiation field with treated target. The patient-specific brass apertures mainly stopped the proton beam from outside of tumors shapes. So it is necessary to discover the occupation dose to hands caused by the activated patient-specific brass apertures, and to evaluate when the radioactive waste is suitable to release.
The dominant radionuclides in activated brass aperture varied and depended on the cooling time. Hence, the occupational dose to hands depends on the time of contact with the activated patient-specific brass apertures. How many dosages will receive by a technologist and how long should the activated patient-specific brass apertures be released?
In this study, we used high purity germanium detector (HPGe) to measure the gamma spectra of the activated brass apertures. We analyzed the spectra to determine the radionuclides and activities. Furthermore, we compared the results from measurements and calculations. First of all, we discussed the full-energy peak efficiency curve of point source with HPGe measurements and MCNP6 calculations. Then MCNP6 is used to determine the efficiency of a volume source for quantification radionuclides. Next, a scenario is assumed that a patient took 20-times proton therapy treatments. The FLUKA was used to calculate the activities and dosages form the activated brass apertures.
The difference of efficiency between calculations and measurements at 5, 10, and 20 cm is 0.92 to 1.14. So we successfully create an HPGe detector geometry model in MCNP6. The measurement of radionuclides in activated brass apertures are similar to the FLUKA calculation. For the activated aperture cooling 3 months, the activities of radionuclides with calculation is overestimated about 2 to 6 times because the distribution of radionuclides in activated brass apertures is non-uniform.
In our study the occupational dose to a technologist’s hand is about 4.96 mSv/y. The activated brass apertures should be conserved for at least 6 months to release.

摘要 ii
Abstract iv
致謝 vi
目錄 vii
表目錄 ix
圖目錄 x
第一章　緒論 1
1.1　引言 1
1.2　文獻回顧 3
第二章 高純度鍺偵檢器能量校正與全能峰效率曲線 7
2.1 高純度鍺偵檢器系統與操作方法 7
2.2 高純度鍺偵檢器相關之文獻探討 11
2.2.1 高純度鍺偵檢器的偵測效率之文獻探討 11
2.2.2 應用高純度鍺偵檢器做箔片活化分析相關之文獻 13
2.3 高純度鍺偵檢器的能量校正 14
2.3.1 能量校正方法 14
2.3.2 能量校正討論 15
2.4 高純度鍺偵檢器的全能峰效率校正 16
2.4.1 全能峰效率校正方法 16
2.4.2 全能峰效率校正討論 19
第三章　被活化的黃銅塊之放射性核種與活度之探討 28
3.1 林口長庚醫院使用的黃銅塊組成與FLUKA蒙地卡羅模擬計算程式 28
3.1.1 林口長庚醫院使用的黃銅塊組成 28
3.1.2 FLUKA 蒙地卡羅模擬計算程式簡介與使用 28
3.2 活化的黃銅塊所含之放射性核種 31
3.3 活化的黃銅塊產生放射性核種之機制探討 38
3.4 150、190和230 MeV的質子射束照射黃銅塊之活化情形 42
第四章 以臨床案例探討黃銅塊活化的曝露劑量與放射性廢棄物外釋的評估 47
4.1 評估工作人員手部劑量與病人額外曝露劑量 47
4.2 評估放射性廢棄物外釋所需冷卻的時間 50
第五章 量測活化的黃銅塊產生之二次中子 54
5.1 箔片活化分析實驗設置 54
5.2 箔片活化分析實驗結果 59
第六章 結論與未來研究 61
第七章 參考文獻 63
第八章 附錄 66

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