高计数率PPAC探测器前端读出电路研制

Radioactive Ion Beam Line in Lanzhou (RIBLL) is the heavy ion radiation beam equipment on Heavy Ion Accelerator in Lanzhou, which can provide a variety of Radioactive Ion Beam （RIB）for physical experiments. In order to improve the efficiency and accuracy of the experiments, we need a high-performance Parallel Plate Avalanche Counter(PPAC) to monitor the RIB online and to measure the path of the incident particles and reaction products. To meet the requirements of high performance PPAC, the readout electronics will be high integration（200 read-out strips）, high-speed（100k/s）,low noise and low power consumption. So，in this project a low noise front-end ASIC will be developed, including low noise preamplifiers and shapers. In which an active leakage current compensation technique for each channel will be taken. Simultaneously，a study of waveform sampling technology based on switched capacitor arrays (SCA) chip will be implemented. Then a high speed multi-channel readout system will be established with the ASIC chip and SCA chip. By the project, the signal readout system will be provided, which is suitable for PPAC, multi- wire proportional ionization chambers, drift chambers and small Time Projection Chambers. Meanwhile，it will prepare a better condition for the research experiments of nuclear physics, particle physics and nuclear astrophysics.

兰州重离子加速器放射性束流线(RIBLL)是我国中能重离子放射性束流装置, 可提供物理实验所需的各种放射性次级束流(RIB)。为了提高实验效率和精度, 需采用高性能平行板雪崩计数器(PPAC)，实现RIB的在线监视、以及在实验中精确测量入射粒子和反应产物的径迹。高性能PPAC对前端电子学提出高集成度(200个读出条)、高速(100k/s) 、低噪声和低功耗的需求。针对这一问题, 本项目将研究、开发前端读出ASIC芯片，实现低噪声前置放大和滤波成形，探索能主动吸收探测器漏电流的补偿电路实现方法；研究基于高速开关电容阵列（SCA）芯片的波形采样；利用该ASIC芯片和SCA芯片建立一套高计数率多通道信号读出系统。通过项目的实施，为PPAC、多丝正比电离室、漂移室及小型时间投影室提供有效的信号读出电路；为核物理、粒子物理与核天体物理实验提供有力的技术支持。

本项目针对兰州重离子加速器放射性束流线(RIBLL)上高性能的探测器对前端电子学高集成度(200个读出条)、高速(100k/s) 、低噪声和低功耗的需求。设计完成了低噪声前置放大和滤波成形ASIC芯片；芯片中实现了主动吸收探测器100nA漏电流的补偿电路；测试结果达到预期指标，动态范围0-500fC，输出信号达峰时间为 50ns /100ns/1us可选，积分非线性小于 0.6%，在达峰时间100ns，10pf输入电容时的等效输入噪声小于800个电子，单通道功耗约为10mW；同时研制了基于高速开关电容阵列芯片 DRS4的波形采样电路，建立了一套基于低噪声高速前放+主放ASIC芯片，和高速波形采样电路的多通道读出电子学系统。通过项目的实施，通过项目的实施，为 PPAC、多丝正比电离室、漂移室及小型时间投影室提供有效的信号读出电路；为核物理、粒子物理与核天体物理实验提供有力的技术支持。