1. The Readout Electronics for Upgrading of BESIII End-capTOF Chunyan Yin University of Science and Technology of China University of Science and Technology of China.

2. Key Laboratory of Technologies of Particle Detection ＆ Electronics, CAS Outline  BESIII and Time-of-Flight Readout System  End-cap TOF(ETOF) Upgrade  BESIII ETOF Readout Electronics for Upgrading  Electronics test of TDIG module 2011/04/12

3. Key Laboratory of Technologies of Particle Detection ＆ Electronics, CAS BESIII and Time-of-Flight Readout System  BESIII is a new detector which aims mainly to measure and identify a substantial fraction of the particles(PID) produced in electron positron collisions.  The TOF detector is the major system for PID in the BES III 3 Fig.1. BESIII cutaway diagram 2011/04/1

4. Key Laboratory of Technologies of Particle Detection ＆ Electronics, CAS  In a BESIII TOF detector, a total of 448 PMTs have been installed in barrel and end-cap sections.  448 channels’ readout system is mainly housed in two VME64xP crates  The whole TOF readout system has been installed in the spectrometer and met the requirement of the physics experiments.  The system accomplished to measure the arrival time of PMT signals from the TOF detector and achieved a timing resolution of 25 ps. BESIII and Time-of-Flight Readout System Fig.3. TOF readout system crate(VME64xP) crate with all modules installed 2011/04/14 Fig.2 Block diagram of BESIII TOF readout system

5. Key Laboratory of Technologies of Particle Detection ＆ Electronics, CAS BESIII and Time-of-Flight Readout System  Publication: Shubin Liu, Changqing Feng, et al. BES III Time-of-Flight readout system. IEEE TRANSACTIONS ON NUCLEAR SCIENCE, VOL. 57, NO. 2, APRIL 2010: 419-427; Changqing Feng, Shubin Liu, et al. Electronics of BESIII TOF Monitor System. IEEE TRANSACTIONS ON NUCLEAR SCIENCE, VOL. 57, NO. 2, APRIL 2010:463-466; Hao Li, Shubin Liu, et al. TOF Clock System for BES III. IEEE TRANSACTIONS ON NUCLEAR SCIENCE, VOL. 57, NO. 2, APRIL 2010: 442-445; F.A. Harris, J.W. Kennedy, et al. BES3 time-of-flight monitoring system. Nucl. Instr. and Meth. A 48477(2008); 52011/04/1

6. Key Laboratory of Technologies of Particle Detection ＆ Electronics, CAS BESIII ETOF Upgrade  Target: Intrinsic time resolution 1.4 GeV (95%C.L.).  Intrinsic(Pi/K): 90ps -> 50ps  Total(Pi/K): 138ps -> 80ps PID of Pi/K @ 2ơ: 1.1GeV/c -> 1.4 GeV/c  Multigap Resistive Plate Chamber(MRPC) technology, is proposed to be the detector 62011/04/1

7. Key Laboratory of Technologies of Particle Detection ＆ Electronics, CAS Multi-gap Resistive Plane Chamber  MRPC is major new detector technology, which is a stack of resistive glass plates with a series of uniform gas gaps.  Thin gap -> fast signal and good time resolution  Multi gaps -> increase the signal and efficiency 2011/04/1 Fig.4 The structure of MRPC 7

8. Key Laboratory of Technologies of Particle Detection ＆ Electronics, CAS Layout of End-cap MRPC  In the end-cap section, the double layers of MRPC are designed.  End-cap section will be composed of 72 MRPC modules  36 modules are located at top, the others are at bottom. 2011/04/1 Fig.5 Layout of End-cap MRPC 8

9. Key Laboratory of Technologies of Particle Detection ＆ Electronics, CAS BESIII ETOF Readout Electronics for Upgrading 2011/04/1  The readout electronics system contains several modules:  FEE(Front-End Electronics) module(IHEP): Amplifies and discriminates the MRPC signal using NINO  TDIG(Time-digital)module (USTC): Receives and digitalizes the signal from FEE by 9 HPTDC chips with the resolution of less than 20 ps  CTTP(Coincidence-threshold- test-power) module(USTC): Provides power, test signal and etc.to FEE module.  Clock Master module Fig.6 Block diagram of Time-of-Flight readout system 9

10. Key Laboratory of Technologies of Particle Detection ＆ Electronics, CAS BESIII ETOF Readout Electronics for Upgrading  Each MRPC module includes 24 detector channels;FEE module:24 channels;TDIG module:72 channels  The TOF electronics should process 1728 (24*72 )channels signal  The readout electronics system includes: 72 FEE modules will be located inside of the spectrometer 24 TDIG modules and 2 CTTP modules are essential and are located outside of the spectrometer 2 VME crates are required for east and west ETOF, each crate contains12 TDIG modules+ 1 CTTP module + 1 Clock module Fig.6 Block diagram of Time-of-Flight readout system 2011/04/110

11. Key Laboratory of Technologies of Particle Detection ＆ Electronics, CAS TDIG module 2011/04/1  Each TDIG module receives and digitalizes the signals from FEE using 9 HPTDC chips  HPTDC runs in very high resolution mode and achieves time measurement with the resolution of less than 20 ps  Each TDIG: Corresponding to 3 MRPC modules and importing 72 channels  Based on VME Bus  FPGA packs and transmits the data to a DAQ system via CPLD and VME bus  CPLD configures the FPGA on- line and is the interface between VME bus and TDIG module Fig.7 Block diagram of TDIG module 11

12. Key Laboratory of Technologies of Particle Detection ＆ Electronics, CAS Status of TDIG module Design 2011/04/1 Fig.8 TDIG module  The design of TDIG module have been accomplished  Major chips run well and meet the demand  The resolution of TDIG module has been tested and meets the requirement basically 12

13. Key Laboratory of Technologies of Particle Detection ＆ Electronics, CAS Electronics test of TDIG module 2011/04/1  Using “cable delay test” to test the timing resolution of the TDIG module  The histogram chart obtained for the time measurement of one channel is shown in Fig. 9. Fig.9 Cable delay test for readout system resolution 13 RMS=15.9715ps

14. Key Laboratory of Technologies of Particle Detection ＆ Electronics, CAS Summary  MRPC technology meets the demand of the BESIII ETOF upgrading  ETOF Readout Electronics system is designed  The whole electronics system will be installed and tested 2011/04/114

15. Key Laboratory of Technologies of Particle Detection ＆ Electronics, CAS Thanks! 152011/04/1