In alpha radionuclide therapy, an optical fiber-based alpha particle detector is a new tool that could possibly be employed for the direct detection of alpha particles in subjects. Thus, in the present study, we developed an optical fiber-based alpha particle detector. The alpha particle detector was made of a 1mm diameter, 10 cm long plastic double clad optical fiber drilled a 0.7 mm diameter, 2 mm depth open space at the one end of the fiber. Silver-doped zinc sulfide (ZnS (Ag)) was painted inside this open space to form a ZnS(Ag) small scintillation chamber. To conduct performance comparisons, we also developed a fiber detector using the same fiber in which a Ce-doped Lu_1.8Y_0·2SiO₅ (LYSO(Ce)) scintillator with dimensions of 0.32 mm × 0.5 mm × 5 mm was inserted. Both fiber detectors were wrapped in aluminized Mylar and optically coupled to a position sensitive photomultiplier tube, before calculating the two-dimensional distributions, energy, and pulse shape spectra. For 5.5-MeV alpha particles, the ZnS(Ag) fiber detector produced ~ 5 times larger pulse heights and the count rate was ~2 times higher compared with those using the LYSO(Ce) fiber detector. For the maximum energy 2.28-MeV beta particles and 0.66-MeV gamma photons, the ZnS(Ag) fiber detector produced no counts, but it yielded small counts from natural alpha particles. Our results confirmed that the ZnS(Ag) fiber detector developed in this study could selectively detect alpha particles and it was insensitive to beta particles and gamma photons.

在 α 放射性核素治疗中，基于光纤的 α 粒子探测器是一种新工具，可能用于直接检测受试者中的 α 粒子。因此，在本研究中，我们开发了一种基于光纤的 α 粒子探测器。阿尔法粒子探测器由直径为 1 毫米、长为 10 厘米的塑料双包层光纤制成，在光纤的一端钻有直径为 0.7 毫米、深度为 2 毫米的开放空间。掺银硫化锌（ZnS（Ag））被涂在这个开放空间内，形成一个ZnS（Ag）小闪烁室。为了进行性能比较，我们还开发了一种使用相同光纤的光纤检测器，其中掺 Ce Lu _1.8 Y _0·2 SiO ₅插入尺寸为 0.32 mm × 0.5 mm × 5 mm 的 (LYSO(Ce)) 闪烁体。在计算二维分布、能量和脉冲形状光谱之前，两个光纤探测器都包裹在镀铝聚酯薄膜中，并与位置敏感的光电倍增管光学耦合。对于 5.5-MeV α 粒子，与使用 LYSO(Ce) 光纤检测器的相比，ZnS(Ag) 光纤检测器产生的脉冲高度高约 5 倍，计数率高约 2 倍。对于最大能量 2.28-MeV β 粒子和 0.66-MeV 伽马光子，ZnS(Ag) 光纤探测器没有产生任何计数，但它从天然 α 粒子产生少量计数。我们的结果证实，本研究中开发的 ZnS(Ag) 光纤探测器可以选择性地检测 α 粒子，并且对 β 粒子和 γ 光子不敏感。