peter-bernd otte - 8 th march 2010 cb collaboration meeting, mainz
Post on 14-Jan-2016
214 Views
Preview:
TRANSCRIPT
Peter-Bernd Otte - 8th March 2010CB collaboration meeting, Mainz
today @DPG
1. New Moeller electronics 1. New Moeller electronics
2. Status of new trigger 2. cellular cluster counter (see Edinburgh talk)
What for?◦ Measure: beam polarity◦ Constituents: tagger, Moeller radiator, electronics◦ essential information for many experiments
Why built it new from scratch? ◦ faster
Used parts:◦ Splitter◦ Trigger◦ TDC (8x)◦ Readout of data
Realised on one FPGA (VUPROM) card◦ One VME CPU to read histograms after
measurement Time to save an event: 20ns Lifetime @ 2nA
◦ 99,999% (with gate)◦ 99% (without Gate)
outputinput
clock
logic cell („modules“):
programmable switches
Interconnection (“cables”):
“has” 1000’s of “modules” and “cables” ~300 I/O signals configuration via software
behaviour of cells and interconnection Not a CPU! Can act as: logic, scaler, TDC, …
New electronic cards arrived (10 cards) „VUPROM 2“ from GSI
◦ FPGA: „Virtex 4“ from Xilinx◦ 224 inputs, 32 outputs, LVDS◦ VMEbus connectivity◦ cheap: 2k€ apiece
TDC programed in FPGA:◦ RMS=30ps
Make use of propagation timetrough smallest entities inside FPGA
startend
How are these TDCs read out?How are these TDCs read out?
“Measure”-FSM1. Wait for 1st hit2. Wait for 2nd hit3. Compute time
differences and save temporally
2 Finite state machines (FSM):• (“Acqu Root on FPGA”)
“Store”-FSM1. Read RAM2. Increase Value by
13. Write RAM
• Each step needs 20ns• FSMs run in parallel
Add more channels without loosing lifetime• One FSM per TDC and per histogram
Detailed view of FPGA
1.8k cells used (9%)
inout
Old New
readout time 20 µs 20ns
lifetime ~50% > 95%
size 1 VME module
measured yesterday:
beam current: 5nA, 30min count asymmetry:
◦ Pfoil not clear yet
)%6(4.3
NN
NNA
N+ N-
improve calibration◦ eliminate ripples
arising from binning
connect more channels◦ Better statistics (@ constant lifetime!)
Possible triggersStatus of hardware
Planned so far:◦ Improved cluster counter
(cellular automata logic)◦ Coplanarity◦ in conjunction with PID:
differentiate charged/uncharged particles for above triggers
◦ Single Tagger signals for detector tests
Include (all) detectors...
Possible to include all detectors◦ All CB crystals (672x 720 cable pairs)◦ All PID stripes (24x)◦ Tagger channels (352x)◦ Endpoint Tagger (~64x)◦ TOF-Panels◦ Inner TAPS crystals (72x)◦ TAPS crystals and vetos (384x)
TAPS electronics has output of all CFD
Trigger modules are available
Moeller electronics working◦ New technique, 106 faster
Trigger◦ Enough inputs: feasible to include signals from all
detectors◦ Coming weeks: Installation of new trigger
electronics in parallel to existing
◦ Help to include TAPS needed
top related