Lee Suk Kyoung, Cudry Fadia, Lin Yun Fei, Lingenfelter Steven, Winney Alexander H, Fan Lin, Li Wen
Department of Chemistry, Wayne State University, Detroit, Michigan 48202, USA.
Rev Sci Instrum. 2014 Dec;85(12):123303. doi: 10.1063/1.4903856.
A new time- and position-sensitive particle detection system based on a fast frame CMOS (complementary metal-oxide semiconductors) camera is developed for coincidence ion imaging. The system is composed of four major components: a conventional microchannel plate/phosphor screen ion imager, a fast frame CMOS camera, a single anode photomultiplier tube (PMT), and a high-speed digitizer. The system collects the positional information of ions from a fast frame camera through real-time centroiding while the arrival times are obtained from the timing signal of a PMT processed by a high-speed digitizer. Multi-hit capability is achieved by correlating the intensity of ion spots on each camera frame with the peak heights on the corresponding time-of-flight spectrum of a PMT. Efficient computer algorithms are developed to process camera frames and digitizer traces in real-time at 1 kHz laser repetition rate. We demonstrate the capability of this system by detecting a momentum-matched co-fragments pair (methyl and iodine cations) produced from strong field dissociative double ionization of methyl iodide.
为了实现符合离子成像，开发了一种基于快速帧互补金属氧化物半导体（CMOS）相机的新型时间和位置敏感粒子检测系统。该系统由四个主要部分组成：传统的微通道板/磷光屏离子成像仪、快速帧CMOS相机、单阳极光电倍增管（PMT）和高速数字化仪。该系统通过实时质心算法从快速帧相机收集离子的位置信息，同时通过高速数字化仪处理的PMT定时信号获得到达时间。通过将每个相机帧上离子斑的强度与PMT相应飞行时间谱上的峰值高度相关联，实现了多击中能力。开发了高效的计算机算法，以1kHz的激光重复频率实时处理相机帧和数字化仪迹线。我们通过检测由甲基碘的强场解离双电离产生的动量匹配共碎片对（甲基和碘阳离子）来证明该系统的能力。
