Starovoitova Valeriia N, Tchelidze Lali, Wells Douglas P
Idaho State University, Idaho Accelerator Center, 1500 Alvin Ricken Dr, Pocatello, ID 83201, United States.
Idaho State University, Idaho Accelerator Center, 1500 Alvin Ricken Dr, Pocatello, ID 83201, United States.
Appl Radiat Isot. 2014 Feb;85:39-44. doi: 10.1016/j.apradiso.2013.11.122. Epub 2013 Dec 11.
In this study, we discuss producing radioisotopes using linear electron accelerators and address production and separation issues of photoneutron (γ,n) and photoproton (γ,p) reactions. While (γ,n) reactions typically result in greater yields, separating product nuclides from the target is challenging since the chemical properties of both are the same. Yields of (γ,p) reactions are typically lower than (γ,n) ones, however they have the advantage that target and product nuclides belong to different chemical species so their separation is often not such an intricate problem. In this paper we consider two examples, (100)Mo(γ,n)(99)Mo and (68)Zn(γ,p)(67)Cu, of photonuclear reactions. Monte-Carlo simulations of the yields are benchmarked with experimental data obtained at the Idaho Accelerator Center using a 44MeV linear electron accelerator. We propose using a kinematic recoil method for photoneutron production. This technique requires (100)Mo target material to be in the form of nanoparticles coated with a catcher material. During irradiation, (99)Mo atoms recoil and get trapped in the coating layer. After irradiation, the coating is dissolved and (99)Mo is collected. At the same time, (100)Mo nanoparticles can be reused. For the photoproduction method, (67)Cu can be separated from the target nuclides, (68)Zn, using standard exchange chromatography methods. Monte-Carlo simulations were performed and the (99)Mo activity was predicted to be about 7MBq/(g(⁎)kW(⁎)h) while (67)Cu activity was predicted to be about 1MBq/(g(⁎)kW(⁎)h). Experimental data confirm the predicted activity for both cases which proves that photonuclear reactions can be used to produce radioisotopes. Lists of medical isotopes which might be obtained using photonuclear reactions have been compiled and are included as well.
在本研究中，我们讨论了使用线性电子加速器生产放射性同位素的问题，并探讨了光中子（γ，n）和光质子（γ，p）反应的生产及分离问题。虽然（γ，n）反应通常能产生更高的产率，但由于产物核素和靶核的化学性质相同，从靶中分离产物核素具有挑战性。（γ，p）反应的产率通常低于（γ，n）反应，然而它们具有靶核素和产物核素属于不同化学物种的优势，因此它们的分离通常不是一个复杂的问题。在本文中，我们考虑了光核反应的两个例子，即（100）Mo（γ，n）（99）Mo和（68）Zn（γ，p）（67）Cu。利用在爱达荷加速器中心使用44MeV线性电子加速器获得的实验数据，对产率的蒙特卡罗模拟进行了基准测试。我们提出了一种用于光中子生产的运动学反冲方法。该技术要求（100）Mo靶材料为涂覆有捕集材料的纳米颗粒形式。在辐照过程中，（99）Mo原子反冲并被困在涂层中。辐照后，溶解涂层并收集（99）Mo。同时，（100）Mo纳米颗粒可以重复使用。对于光生产方法，可以使用标准的交换色谱方法从靶核素（68）Zn中分离出（67）Cu。进行了蒙特卡罗模拟，预测（99）Mo活度约为7MBq/（g⁎kW⁎h），而（67）Cu活度约为1MBq/（g⁎kW⁎h）。实验数据证实了这两种情况下的预测活度，这证明光核反应可用于生产放射性同位素。还编制并纳入了可能通过光核反应获得的医用同位素清单。
