Nuclear Techniques ›› 2016, Vol. 39 ›› Issue (11): 110402-110402.doi: 10.11889/j.0253-3219.2016.hjs.39.110402


Design of long-distance and large-dynamic-range of charge measurement circuit

XU Fuzhen1,2, YANG Hongguan1, CHANG Jinfan2, LIU Xiang2   

  1. 1 School of Physics and Electronics, Hu'nan University, Changsha 410082, China;
    2 State Key Laboratory of Particle Detection and Electronics, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
  • Received:2016-03-01 Revised:2016-04-02 Online:2016-11-10 Published:2016-11-12


Background: The air shower core detector array (SCDA) is one of the important detectors to be constructed at the heart of the KM2A (one kilometer square extensive air shower array) with the area of 5 000 m2, in large high altitude air shower observatory (LHAASO). Purpose: This study aims to design the readout electronics of SCDA for accurate charge measurement of the input photomultiplier tube (PMT) signal for three orders of magnitude. Methods: A 50-Ω impedance match between the "virtual" grounding and input end is employed to measure the charge by the charge integration method. The feasibility of impedance match is verified by "Pspice" simulation tool. The output current signal from the PMT is collected and processed by the readout electronics of charge integration circuit via coaxial cable. Results: The performance testing in the laboratory shows that the designed circuit satisfies design requirements of the long-distance and large-dynamic-range charge measurement. Conclusion: The simulation and testing of "virtual" grounding impedance match validate the feasibility of this circuit. The readout electronics fulfills the application requirements of SCDA.

Key words: LHAASO, SCDA, Charge integrator, Impedance match, Dynamic range

CLC Number: 

  • TL99