Kambali I, Suryanto H
Center for Radioisotope and Radiopharmaceutical Technology, National Nuclear Energy Agency (BATAN), Puspiptek Area, Serpong, South Tangerang, Indonesia.
Australas Phys Eng Sci Med. 2016 Jun;39(2):403-12. doi: 10.1007/s13246-016-0426-1. Epub 2016 Feb 11.
Routine production of F-18 radionuclide using proton beams accelerated in a cyclotron could potentially generate residual radioisotopes in the cyclotron vicinity which eventually become major safety concerns over radiation exposure to the workers. In this investigation, a typical 11-MeV proton, self-shielded cyclotron has been assessed for its residual radiation sources in the cyclotron's shielding, tank/chamber, cave wall as well as target system. Using a portable gamma ray spectroscopy system, the radiation measurement in the cyclotron environment has been carried out. Experimental results indicate that relatively long-lived radioisotopes such as Mn-54, Zn-65 and Eu-152 are detected in the inner and outer surface of the cyclotron shielding respectively while Mn-54 spectrum is observed around the cyclotron chamber. Weak intensity of Eu-152 radioisotope is again spotted in the inner and outer surface of the cyclotron cave wall. Angular distribution measurement of the Eu-152 shows that the intensity slightly drops with increasing observation angle relative to the proton beam incoming angle. In the target system, gamma rays from Co-56, Mn-52, Co-60, Mn-54, Ag-110 m are identified. TALYS-calculated nuclear cross-section data are used to study the origins of the radioactive by-products.
利用回旋加速器加速的质子束常规生产F-18放射性核素可能会在回旋加速器附近产生残余放射性同位素，这最终成为工作人员辐射暴露的主要安全隐患。在本研究中，对一台典型的11兆电子伏特自屏蔽回旋加速器在其屏蔽层、水箱/腔室、洞穴壁以及靶系统中的残余辐射源进行了评估。使用便携式伽马射线能谱系统，对回旋加速器环境中的辐射进行了测量。实验结果表明，在回旋加速器屏蔽层的内表面和外表面分别检测到了相对长寿命的放射性同位素，如Mn-54、Zn-65和Eu-152，而在回旋加速器腔室周围观察到了Mn-54能谱。在回旋加速器洞穴壁的内表面和外表面再次发现了弱强度的Eu-152放射性同位素。Eu-152的角分布测量表明，强度相对于质子束入射角随着观察角的增加而略有下降。在靶系统中，识别出了来自Co-56、Mn-52、Co-60、Mn-54、Ag-110m的伽马射线。利用TALYS计算的核截面数据来研究放射性副产物的来源。
