隨著正子造影技術(Positron Emission Tomography, PET)於國內的推廣發展及各醫用迴旋加速器中心(Cyclotron center)的設立，國內迴旋加速器運轉人員及放射性藥劑生產人員的需求也成長許多。隨著輻防觀念的提升迴旋加速器運轉時對相關工作人員的影響也儼然成為設立迴旋加速器中心時首重考慮的問題。本文針對GE-MINItrac迴旋加速器，測量加速器周圍之輻射暴露率，以評估迴旋加速器室之空間劑量分佈。本文是利用ESM Eberline FH40GL加馬輻射手提式偵檢器及NE Technology Mark 7 NRM中子偵檢器，量測迴旋加速器室光子及中子空間劑量的分佈，結果顯示高度100公分平面中，光子場遮罩體表面最高劑量率為19.3 μSv/h，平均表面劑量率為5.639 μSv/h，距遮罩體表面100公分處的劑量率最高為13.0 μSv/h，平均劑量率為3.660 μSv/h。中子場遮罩體表面最高劑量率可達5.9 μSv/h，平均表面劑量率可達1.713 μSv/h，距遮罩體表面100公分處的劑量率最高為3.8 μSv/h，平均劑量率為1.418 μSv/h。如距離遮罩體表面100公分處連續H暴露2000小時，光子累積劑量為7.320mSv，中子2.836mSv，其結果符合遊離輻射防護法規定工作人員每連續五年過期之有效等效劑量不得超過100mSv，且任何單一年內之有效等效劑量不得超過50mSv之劑量限制值。

As the positron emission tomography technology is developing rapidly and the medical cyclotron centers have been established in Taiwan, the requirements for the cyclotron operation staff and the radiation pharmaceutics have been raised. To comply with the radiation protection norms, the influence of cyclotron radiation on the cyclotron staff has become an important parameter when founding a cyclotron center. This paper examined the exposure rate of the GE-MINItrac cyclotron and estimated the radiation distribution in a cyclotron room. Devices used include ESM Eberline FH40GL for measuring the gamma radiation field and the NE Technology Mark 7 NRM for the neutron. The result showed that, at the horizontal plan of height of 100 centimeters, the maximum and mean photon absorption rates are 19.3 and 5.639μSv/h at the shielding surface, and at the position of 100 centimeters away from shielding surface are 13.0 and 3.660μSv/h. The neutron maximum and mean absorption rates are 5.9 and l.713μSv/h at the shielding surface, and at the position of 100 centimeters away from shielding surface are 3.8 and 1.418μSv/h. To integral the continue exposure for 2000 hours at the position of 100 centimeters away from shielding surface, the photon and neutron accumulate dose are 7.320, 2.836 mSv. The annual absorption dose is lower than the regulation limit; effective dose does not extend then 100mSv in contiguously five years, and neither extends 50mSv in each year.