中国锦屏地下实验室是目前世界上岩石覆盖最深的深地实验室,对宇宙线μ子具有良好的屏蔽作用,具有极低的宇宙线通量,因此适用于开展对稀有物理事例的探测实验。目前,包括中国暗物质实验(China Dark matter EXperiment,CDEX)、粒子和天...中国锦屏地下实验室是目前世界上岩石覆盖最深的深地实验室,对宇宙线μ子具有良好的屏蔽作用,具有极低的宇宙线通量,因此适用于开展对稀有物理事例的探测实验。目前,包括中国暗物质实验(China Dark matter EXperiment,CDEX)、粒子和天体物理氙实验(Particle and Astrophysical Xenon Experiments,PandaX)、锦屏深地核天体物理实验装置(Jinping Underground Nuclear Astrophysics Experiment,JUNA)等实验组已经入驻锦屏实验室,对暗物质直接探测、无中微子双β衰变、天体核反应等一系列稀有物理事例进行实验探测,并给出了一系列国际先进水平的研究成果。本文总结了中国锦屏地下实验室自成立以来的发展过程和本底控制情况,并对实验室中各个实验组所开展实验的物理意义、实验原理、关键技术、物理成果等进行介绍,同时给出实验组接下来的实验计划。展开更多
Purpose This work proposes a clock and data alignment scheme for the readout electronics system of the future PandaX-nT dark matter detection experiments.Since the waveform information of the photomultiplier signal is...Purpose This work proposes a clock and data alignment scheme for the readout electronics system of the future PandaX-nT dark matter detection experiments.Since the waveform information of the photomultiplier signal is obtained by accumulating all acquisition channels of the front-end digitization module(FDM),it is required that each FDM acquisition channel should be synchronized.Methods The readout electronics system is composed of a clock distribution module,64 FDMs,and 4 data acquisition(DAQ)modules.The multi-board synchronous acquisition circuit can provide the same REF CLOCK and SYSREF signal for multiple FDMs boards to ensure the alignment of the sampled data collected by the analog-to-digital converter.The data aggregation circuit can ensure that the sampled data of multiple FDM boards are aligned with each other when they are aggregated to the DAQ board.Results and conclusions The functional verification test results show that the synchronization between the prototype electronics channels is less than 80 ps,thus enabling to meet the requirements of the readout electronics prototype of PandaX-nT.展开更多
Background:PandaX-III is aimed to search for neutrinoless double beta decay of 136Xe at China Jinping Underground Laboratory.To test various design features of PandaX-III detector,a prototype TPC with 20 kg Xe contain...Background:PandaX-III is aimed to search for neutrinoless double beta decay of 136Xe at China Jinping Underground Laboratory.To test various design features of PandaX-III detector,a prototype TPC with 20 kg Xe containing inside is built.Purpose:Front-end boards installed inside the waterproof vessel integrate charge of Micromegas signal,digitize signal waveform and send data packet to back-end board.Frontend boards receive synchronous information(global clock,global trigger,etc.),as well as command messages from back-end board.In order to satisfy the requirement of high data throughput and multiple types of synchronous data transmission,we propose an optical fiber link to communicate between front-end board and back-end board.Methods:Communication of serial transmission is performed using FPGA-based gigabit transceiver with a 1 Gbit/s point-to-point speed.A dedicated user-defined protocol is implemented for various kinds of data transmission.Results:To validate the performance of this link,bit error rate and eye diagram were tested.Preliminary joint test with detector was conducted in Shanghai.All test results showed sufficient data bandwidth and stable performance.Conclusion:To satisfy the requirement for data transmission between front-end board and back-end board in PandaX-III TPC detector readout,an FPGA-based gigabit serial link is designed and tested.This design shows good performance and will be applied to the R&D of PandaX-III TPC.展开更多
文摘Purpose This work proposes a clock and data alignment scheme for the readout electronics system of the future PandaX-nT dark matter detection experiments.Since the waveform information of the photomultiplier signal is obtained by accumulating all acquisition channels of the front-end digitization module(FDM),it is required that each FDM acquisition channel should be synchronized.Methods The readout electronics system is composed of a clock distribution module,64 FDMs,and 4 data acquisition(DAQ)modules.The multi-board synchronous acquisition circuit can provide the same REF CLOCK and SYSREF signal for multiple FDMs boards to ensure the alignment of the sampled data collected by the analog-to-digital converter.The data aggregation circuit can ensure that the sampled data of multiple FDM boards are aligned with each other when they are aggregated to the DAQ board.Results and conclusions The functional verification test results show that the synchronization between the prototype electronics channels is less than 80 ps,thus enabling to meet the requirements of the readout electronics prototype of PandaX-nT.
基金This work is supported by the National Natural Science Foundation of China(Grant No.11222552)the National Key R&D Program of China(Grant No.2016YFA0400303).
文摘Background:PandaX-III is aimed to search for neutrinoless double beta decay of 136Xe at China Jinping Underground Laboratory.To test various design features of PandaX-III detector,a prototype TPC with 20 kg Xe containing inside is built.Purpose:Front-end boards installed inside the waterproof vessel integrate charge of Micromegas signal,digitize signal waveform and send data packet to back-end board.Frontend boards receive synchronous information(global clock,global trigger,etc.),as well as command messages from back-end board.In order to satisfy the requirement of high data throughput and multiple types of synchronous data transmission,we propose an optical fiber link to communicate between front-end board and back-end board.Methods:Communication of serial transmission is performed using FPGA-based gigabit transceiver with a 1 Gbit/s point-to-point speed.A dedicated user-defined protocol is implemented for various kinds of data transmission.Results:To validate the performance of this link,bit error rate and eye diagram were tested.Preliminary joint test with detector was conducted in Shanghai.All test results showed sufficient data bandwidth and stable performance.Conclusion:To satisfy the requirement for data transmission between front-end board and back-end board in PandaX-III TPC detector readout,an FPGA-based gigabit serial link is designed and tested.This design shows good performance and will be applied to the R&D of PandaX-III TPC.
