HRS Timing & Related Issues

1. HRS Timing & Related Issues Vincent Sulkosky Massachusetts Institute of Technology SRC Collaboration Meeting February 21st, 2010

2. 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 • T8 (1024 Hz clock)

3. HRS Trigger Definitions • T1/T3: “AND of the OR’s”: • S1-or&&S2-or • “AND” of left-right PMTs of S1 • “AND” of left-right PMTs of S2m • Typically 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”

4. HRS Trigger Diagram

5. Coincidence Trigger Diagram

6. HRS Retiming • L1A directly from weldment • Strobe (≥ 60 ns after L1A) • Overlap results in retimed L1A • If 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.

7. HRS Timing Issues • R-HRS S2m was not setup for self-timing • Some PMTs show considerable after-pulsing • HRS 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

8. HRS Self-Timing (g2p) L-HRS, Dec. 2011 Black: Right; Red: Left

9. HRS ‘Not’ Self-Timing (g2p) R-HRS, Dec. 2011 Black: Right; Red: Left

10. After-pulsing LHRS S1L PMTs

11. After-pulsing LHRS S1R PMTs

12. RHRS S1L PMTs

13. RHRS S1R PMTs

14. L-HRS Trigger TDCs

15. R-HRS Trigger TDCs

16. LHRS S2m

17. LHRS S2m: Double Peaks Clearly not a left-right PMT issue!

18. LHRS S2m: Double Peaks

19. LHRS S2m: 2-to-1 Peak

20. LHRS S2m: Self-timing(?)

21. Plan to Move Forward • Detailed timing diagrams from Spring 2011 • Work with Igor and Tai while both are here • at JLab • Goals: understand the data and develop an algorithm to determine the correct tof