ABSTRACT

An optically read-out glass gas electron multiplier (G-GEM) detector is expected to simplify complicated quality assurance measurements for hadron therapies by imaging the dose distribution of the incident beam. However, the effect of secondary particles from the detector itself has not been well studied. In this paper, we evaluate a design that reduces the secondary particles from the cathode of a G-GEM detector. Specifically, we assembled detectors with thin cathodes and assessed their effect on the secondary particle production in simulations and experiments. The experiments were carried out under 290 MeV/u ¹²C ion bombardment at the Heavy Ion Medical Accelerator in Chiba. The clinical intensity of the thin cathode detector was compared with that of a conventional thick cathode G-GEM detector. The improved chamber design reduced the dose contributions of secondary particles from the cathode without degrading the dose imaging performance.

摘要

光学读出玻璃气体电子倍增器 (G-GEM) 探测器有望通过对入射光束的剂量分布进行成像来简化强子疗法的复杂质量保证测量。然而，来自探测器本身的次级粒子的影响尚未得到很好的研究。在本文中，我们评估了一种减少来自 G-GEM 探测器阴极的二次粒子的设计。具体来说，我们组装了带有薄阴极的探测器，并在模拟和实验中评估了它们对二次粒子产生的影响。实验在 290 MeV/u ^{12 下进行}千叶重离子医学加速器的 C 离子轰击。将薄阴极探测器的临床强度与常规厚阴极 G-GEM 探测器的临床强度进行了比较。改进的腔室设计减少了来自阴极的二次粒子的剂量贡献，而不会降低剂量成像性能。