1. Electronics and DAQ Summary
M. V. Purohit
for
Jing Wei Zhao, Zepu Mao, Huayi Sheng, Ping Ping Zhao, Shudi Gu, Yong Zhao Zhou et al.

2. Vertex Chamber
This device is small and will be considered later – after the workshop.

3. MDC: Choice of Design Schemes
Based on《Q to T converter + HPTDC》
Wire
signal
trigger
Online
VMEbus
Q to T based mainamp
Cern HPTDC
based TDC
Preamp.
Calibration

4. MDC Scheme 2: Based on FADC and HPTDC. Preamp Wire Signal Mainamp Vth
Trigger
VMEbus
timing
Clock
online
Preamp
Wire
Signal
dE/dx
Vth Q
measurement T
Calibration
Mainamp

5. MDC Issues Decision needed on Scheme 1 vs 2
Rests partly on available budget per channel
Many noise issues:
Reflection from ends of cables
Channels closer to beam: no room for preamps on end-plates
Cross-talk; Low noise supplies

6. Block Diagram of the TOF electronics
L-threshold
H_threshold
Start
10ns
L0 trigger
From Online
To Trigger
Pre-amp
Splitter
Stop
PMT Signal
Driver HL
Calibration LL
Delay
From L1 Trigger
ADC
Read-out
TAC +
FADC

7. Barrel electromagnetic Calorimeter Electronics
System block diagram
Preamplifiers
Trigger
Post amplifier V M E
L1 Trigger
C Trigger CL1 CR
(RC)2 ∑
calibration
Fan - out
Charge
measurement
controller Σ B G O

8. EMC issue Major issue is noise reduction
Cost is not a serious problem here

9. Muon Chambers
Number of channels needs to be determined from physics considerations

10. DAQ BESIII’s sub-detectors are: Electronics will consist of five
Vertex Chamber
Main Drift Chamber
TOF plus CCT Counter
Electromagnetic Calorimeter
MUON Identifier
Electronics will consist of five
sub-systems correspondingly.
Total channel amount is about 50K~77K.

11. DAQ Schedule
Software people exist. It is assumed that sufficient number of students will be found as necessary.
Testing of DAQ subsystems must be possible before completion of FEE subsystems. Will help with specifications.
This must include diagnostics.

12. Schematic of BES III TriggerVC
DISC
Hit Count
L0 trigger Logic
FEE
L0P
TOF
DISC
Hit/Seg Count
Global Trigger Logic
MDC
DISC
Track Seg. Finder
Track Finder
DAQ
EMC
BTE Sum
Tile Sum
Tile Processor
Total Ener Sum
L1P MU
DISC
Mu track
CLOCK RF
TTC
2.4 s

13. Trigger Issue Can L0 be used for timing instead of L1?
Should segmentation of of cells match MDC? Might make life simpler.
Interface personnel need to be designated.

14. System-wide issues
Manpower: perhaps sufficient, but experienced people (engineers!) needed. Visits from foreign experts?
Detailed schedules need to be drawn up: 1.5 to 2 years estimate from most groups needs timelines. Interface with other groups. Fallback options.