1. “End station A setup” data analysis Josef Uher

2. Outline Introduction to setup and analysis Quartz bar start counter MA and MCP PMT in the prototype

3. What was analyzed quartz bar start counter 4 pad MCP - PMT ADC Constant Fraction Discriminator prototype 3x MCP PMT (Burle) 2x MA PMT (Hamamatsu) light source -pulse laser “Pilas” Leading Edge Discriminator TDC

4. Tasks for data analysis software develop a timing strategies for start counters develop a calibration procedure for the prototype (determine time offsets for each of all modules, determine single electron timing resolutions) help to tune the setup and find errors

5. What can affect timing resolution? fluctuation of avalanche recoil of photoelectrons from MCP surface charge sharing cross talk electronics noise smear of pulse source (laser)...

6. Average improvement of the timing resolution ~22% Timing resolution vs. Pilas trigger frequency (measured with MA PMT Hamamatsu)

7. Quartz bar start counter

8. quartz bar start counter 4 pad MCP - PMT ADC Leading Edge Discriminator TDC Configuration with ADC gives possibility to correct measured time on pulse height off-line. => better control than in case of CFD

9. ADC correction – how it works? t1t1 t2t2 Time Amplitude TDC threshold TDC spectra ADC vs. TDC Before correctionAfter correction  1 =250 ps  1 =100 ps

10. Quartz bar start counter timing resolution Improvement for single photons from ~350 ps to ~138 ps.

11. Prototype

12. Burle MCP-PMT, raw TDC spectra

13. Hamamatsu MA-PMT, raw TDC spectra

14. MCP and MA PMT timing resolution MA PMT Hamamatsu MCP PMT Burle (raw data only, single photon mode, no corrections) ±58 ±43

15. Pad timing offset maps MA PMT Hamamatsu Without TDC link offset MCP PMT Burle TDC 1TDC 2TDC 3TDC 4 Start Peak position Delay ~1ns

16. Cross talk

17. Cross talk treatment Possible sources of “false pulses”: charge sharing recoiled electrons internal PMT cross talk (wiring) cross talk in amplifiers cross talk in CFD photons bouncing in prototype box

18. Cross talk treatment Cross talk is only in neighborhood pads Cross talk treatment (neighbors)

19. Cross talk can appear in any pad of MCP or MA PMT Cut in certain time after the first pulse Cross talk treatment MCP or MA PMT

20. Cross talk treatment Time [cnt] Events [-] Example of cross talk treatment with time window 15 counts. MCP PMT Burle

21. Cross talk treatment Time [cnt] Events [-] Example of cross talk treatment with time window 15 counts. MCP PMT Burle

22. Cross talk treatment Time [cnt] Events [-] Example of cross talk treatment with time window 15 counts. MCP PMT Burle

23. Cross talk treatment The time window changed from 15 to 27 counts Time [cnt] Events [-] Example of cross talk treatment with time window 27 counts. MCP PMT Burle

24. Time window 15 cnt Time window 27 cnt Cross talk only Cross talk treatment Time [cnt] Events [-] Cross talk spectra with time window 15 and 27 counts. MCP PMT Burle

25. Time window 15 cnt Time window 27 cnt Cross talk treatment Time [cnt] Events [-] Corrected TDC spectra with time window 15 and 27 counts. MCP PMT Burle

26. Cross talk treatment Raw TDC spectrum Time window 1Time window 31 Time [cnt] Events [-] narrow  = 190 ps

27. MCP PMT Burle after cross talk correction improvement 14% 13% Multiple hits Cross talk “frequency” Raw data max.: ~7 Corrected data: ~5

28. Conclusion Influence of Pilas laser on timing resolution discovered. Higher Pilas trigger frequency needed – another Pilas laser will be tested. Repeated measurement of quartz bar start counter timing resolution – still needs more work All slots in the prototype will be tested in near future Effective cross talk treatment was implemented in data analysis code