用于CSRe上16O5+离子精密激光谱学实验的极紫外光子探测系统的研制

高电荷态离子的精密谱学研究不仅为强场QED效应、相对论效应、电子关联效应等基础前沿理论模型的精确检验提供了良好的条件，而且对同位素移动、高电荷态离子光钟等诸多前沿物理研究具有重要意义。为了在兰州重离子加速器冷却储存环的CSRe上开展相对论能量类锂16O5+离子2s_1/2→2p_1/2和2s_1/2→2p_3/2光学跃迁精密测量的激光谱学实验研究，研制了一套适用于前向发射荧光收集测量的新型非拦截式极紫外光子探测系统。该探测系统主要由抛物面型SiC反射镜、镀有CsI的微通道板(MCP)探测器以及高速步进电机等部分组成。在CSRe的高温烘烤环境和超高真空实验环境下，该探测系统能够在不影响储存环内离子束正常运转的同时实现对极紫外波段(50~200 nm)前向发射光子的高效探测，其探测效率较CSRe上现有光子通道倍增管荧光探测器提升约50倍。该探测系统不仅能够为CSRe上高电荷态离子的精密激光谱学实验提供高效实时的探测工具，亦为将来在大科学装置HIAF上开展更高能量、更高电荷态重离子的精密激光谱学实验研究奠定了坚实的基础。

Development of an Ultraviolet Photon Detection System for Precision Laser Spectroscopy of Li-like 16O5+ Ion at the CSRe

Precision measurement of the radiation transition properties of highly charged ions are considered not only provides excellent conditions for precise testing of fundamental theoretical models such as strong field QED effects, relativistic effects, and electron correlation effects, but also contributes to many advanced physics research, including isotope shifts, HCI clock, etc. In order to perform precision laser spectroscopy of lithium-like 16O5+ ions to precisely measure the optical transition energy of 2s_1/2→2p_1/2 and 2s_1/2→2p_3/2 at the experimental cooler storage ring CSRe in Heavy Ion Research Facility in Lanzhou(HIRFL), a new non-destructive ultraviolet photon detection system has been developed for efficient detection of the forward-emitted ultraviolet photons. This detection system is mainly consisted of a SiC-made parabolic reflector, a MCP(Microchannel Plate) coated with CsI and a high-speed stepper motor. In the high temperature baking environment and ultra-high vacuum experimental conditions at the CSRe, this new detection system enables high-efficiency detection of the de-excitation ultraviolet photons without affecting the normal operation of the ion beams at the storage ring, and the collection efficiency is improved by more than 50 times as compared to the previously installed Channeltron photomultiplier photons detector. This new detection system will not only provide an efficient real-time detection tool for the precision laser spectroscopy of highly charged ions at the CSRe, but also lays a solid foundation for future research on precision laser spectroscopy of heavy ions with higher energies and higher charge state at High Intensity heavy-ion Accelerator Facility(HIAF).