Tulej M, Meyer S, Lüthi M, Lasi D, Galli A, Desorgher L, Hajdas W, Karlsson S, Kalla L, Wurz P
Space Research and Planetary Sciences, Physics Institute, University of Bern, CH-3012 Bern, Switzerland.
Laboratory of Particle Physics, Paul Scherrer Institute, CH-5232 Villigen, Switzerland.
Rev Sci Instrum. 2015 Aug;86(8):083310. doi: 10.1063/1.4928063.
High-energy e(-) and π(-) were measured by the multichannel plate (MCP) detector at the PiM1 beam line of the High Intensity Proton Accelerator Facilities located at the Paul Scherrer Institute, Villigen, Switzerland. The measurements provide the absolute detection efficiencies for these particles: 5.8% ± 0.5% for electrons in the beam momenta range 17.5-300 MeV/c and 6.0% ± 1.3% for pions in the beam momenta range 172-345 MeV/c. The pulse height distribution determined from the measurements is close to an exponential function with negative exponent, indicating that the particles penetrated the MCP material before producing the signal somewhere inside the channel. Low charge extraction and nominal gains of the MCP detector observed in this study are consistent with the proposed mechanism of the signal formation by penetrating radiation. A very similar MCP ion detector will be used in the Neutral Ion Mass (NIM) spectrometer designed for the JUICE mission of European Space Agency (ESA) to the Jupiter system, to perform measurements of the chemical composition of the Galilean moon exospheres. The detection efficiency for penetrating radiation determined in the present studies is important for the optimisation of the radiation shielding of the NIM detector against the high-rate and high-energy electrons trapped in Jupiter's magnetic field. Furthermore, the current studies indicate that MCP detectors can be useful to measure high-energy particle beams at high temporal resolution.
位于瑞士维利根保罗·谢尔研究所的高强度质子加速器设施的PiM1束流线处，利用多通道板（MCP）探测器对高能电子（e⁻）和π介子（π⁻）进行了测量。这些测量给出了这些粒子的绝对探测效率：在束流动量范围为17.5 - 300 MeV/c时，电子的探测效率为5.8% ± 0.5%；在束流动量范围为172 - 345 MeV/c时，π介子的探测效率为6.0% ± 1.3%。根据测量确定的脉冲高度分布接近具有负指数的指数函数，这表明粒子在通道内某处产生信号之前穿透了MCP材料。本研究中观察到的MCP探测器的低电荷提取和标称增益与穿透辐射形成信号的 proposed 机制一致。一个非常相似的MCP离子探测器将用于为欧洲航天局（ESA）前往木星系统的JUICE任务设计的中性离子质量（NIM）光谱仪中，以测量伽利略卫星外层大气的化学成分。本研究中确定的穿透辐射探测效率对于优化NIM探测器针对捕获在木星磁场中的高速率和高能电子的辐射屏蔽非常重要。此外，当前研究表明，MCP探测器可用于以高时间分辨率测量高能粒子束。
