Abstract The General Electric (GE®) PETtrace 860 cyclotron at the Missouri University Research Reactor (MURR) facility is used extensively for medical and research radioisotope production. However, no model exists of its performance, and the proton beam’s energy and spatial distribution are unmeasured. Here, an MCNP6 model was developed to improve upon the performance of the cyclotron target systems that are routinely utilized for research and medical radioisotope production. Since the cyclotron beam energy and profile have a significant impact on the efficiency and character of radioisotope production, the MURR cyclotron proton beam energy was measured using high-purity copper stacked foil activation to be 14.6 ± 0.2 MeV, a significant reduction from the stated 16.4 MeV. Phosphor plate imaging was also used to radiographically image the distribution of radioisotope production within the copper foils and characterize the beam spatial and intensity profile. Total target activity was quantified by trapping the 11C on a solid adsorbent and measuring the amount in an ion chamber. Effective target densities were calculated for irradiations conducted with beam currents between 5 and 40 μA. The measured beam and target characteristics were used to develop an MCNP6 model of 11C production. Through use of the model, it was determined that the targets were, at most, 41% efficient as a thick target design resulting in up to 11.80-MeV average protons impinging on the target walls leading to potential contamination from hot ion recoils.

中文翻译：

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使用 GE PETtrace 回旋加速器通过 14N(p,α) 反应开发用于 11C 生产的实验验证 MCNP6 模型

摘要 密苏里大学研究反应堆 (MURR) 设施中的通用电气 (GE®) PETtrace 860 回旋加速器广泛用于医疗和研究放射性同位素生产。然而，它的性能没有模型存在，质子束的能量和空间分布是不可测量的。在这里，开发了一个 MCNP6 模型，以提高通常用于研究和医用放射性同位素生产的回旋加速器目标系统的性能。由于回旋束能量和轮廓对放射性同位素生产的效率和特性有显着影响，因此使用高纯铜叠层箔活化测量的 MURR 回旋加速器质子束能量为 14.6 ± 0.2 MeV，比规定的 16.4 显着降低兆伏。荧光板成像还用于对铜箔内放射性同位素产生的分布进行射线照相成像，并表征光束空间和强度分布。通过将 11C 捕获在固体吸附剂上并测量离子室中的量来量化总目标活性。计算了以 5 到 40 μA 之间的束电流进行的辐照的有效目标密度。测量的光束和目标特性用于开发 11C 生产的 MCNP6 模型。通过使用该模型，确定目标作为厚目标设计的效率最多为 41%，导致高达 11.80-MeV 的平均质子撞击目标壁，从而导致热离子反冲的潜在污染。