关键词: 
重离子治癌 /
大面积平行板雪崩计数器 /
位置分辨

摘要: 简单介绍了重离子治癌的原理， 叙述了一种用于重离子治癌的大面积平行板雪崩计数器， 它主要由入射窗、 x位置栅极、 中心阳极、 y位置栅极和出射窗组成. 使用C3F8气体， 气压700 Pa， 阳极电压为700 V， 两阴极接地, 电子学成形时间常数为2 μs, 测试得到的位置分辨修正后为0.54 mm(FWHM). 通过与国内外同类装置比较， 认为这一分辨已经满足了重离子治癌装置的要求. he principle of the heavyion therapy is introduced in this article. In order to precisely determine the irradiation profiles and positions of scanned heavyion beams, we developed a large area parallel plate avalanche counter(PPAC). The detector consists of one anode, two cathodes and two windows with 250 mm×250 mm active area . It was measured at an anode voltage of 700 V and with flowing C3F8 gas at the pressure of 700 Pa. A position resolution of 0.54 mm by correction was obtained with an αsource. As compared with the similar devices, we consider the position resolution of the PPAC can satisfy the requirement of the facility of heavyion therapy.