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HRS Timing & Related Issues. Vincent Sulkosky Massachusetts Institute of Technology SRC Collaboration Meeting February 21 st , 2010. Refresher on Triggers. T1 (RHRS Main) T2 (RHRS Efficiency) T3 (LHRS Main) T4 (LHRS Efficiency) T5 (Coincidence RHRS&&LHRS) T6 (BB E-plane) T7 HAND - PowerPoint PPT Presentation
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HRS Timing & Related Issues
Vincent SulkoskyMassachusetts Institute of Technology
SRC Collaboration MeetingFebruary 21st, 2010
Refresher on TriggersT1 (RHRS Main)T2 (RHRS Efficiency)T3 (LHRS Main)T4 (LHRS Efficiency)T5 (Coincidence RHRS&&LHRS)T6 (BB E-plane)T7 HANDT8 (1024 Hz clock)
HRS Trigger DefinitionsT1/T3: “AND of the OR’s”:
S1-or&&S2-or“AND” of left-right PMTs of S1“AND” of left-right PMTs of S2mTypically S2m right PMTs are delayed 20 ns wrt S2m left PMTs (self-timing)“S2-or” delayed wrt “S1-or”: 20-30 ns
T2/T4: (2 out-of 3 trigger) includes GC and exclusive to T1/T2
HRS retiming (strobe): “S1-or||S2-or”
HRS Trigger Diagram
Coincidence Trigger Diagram
HRS RetimingL1A directly from weldmentStrobe (≥ 60 ns after L1A)Overlap results in retimed L1AIf no overlap, circuit times out and
produces a delayed retimed L1A ~ 200 ns later to force gates and stops, i.e., this happens for T8 triggers.
HRS Timing IssuesR-HRS S2m was not setup for self-
timingSome PMTs show considerable after-
pulsingHRS scintillator class by default takes
the latest hit (right before the stop)See multiple peaks in both HRS
scintillators, though appears to be localized more to S2m
HRS Self-Timing (g2p)
L-HRS, Dec. 2011Black: Right; Red: Left
HRS ‘Not’ Self-Timing (g2p)
R-HRS, Dec. 2011Black: Right; Red: Left
After-pulsing LHRS S1L PMTs
After-pulsing LHRS S1R PMTs
RHRS S1L PMTs
RHRS S1R PMTs
L-HRS Trigger TDCs
R-HRS Trigger TDCs
LHRS S2m
LHRS S2m: Double Peaks
Clearly not a left-right PMT issue!
LHRS S2m: Double Peaks
LHRS S2m: 2-to-1 Peak
LHRS S2m: Self-timing(?)
Plan to Move ForwardDetailed timing diagrams from
Spring 2011Work with Igor and Tai while both are
hereat JLabGoals: understand the data and
develop an algorithm to determine the correct tof