High Rate Photon Irradiation Test with an 8-Plane TRT Sector Prototype

1. High Rate Photon Irradiation Test with an 8-Plane TRT Sector Prototype J. Valls A. Romaniouk

2. Massada Fortress and Dead Sea …2 days to visit Israel !!

3. Outline • Goals • Experimental Setup • Weizmann Institute Irradiation Facility • Results • Occupancies and Rates • Occupancy Cross-talk • Hit Detection Efficiencies • Summary

4. Goals • Characterize and study the performance of final FE electronics • Demonstrate basic operation of the detector at high counting rates • Two high rate irradiation tests planned • CERN X5 GIF 137Cs (662 keV photons), 0.5 MHz • Weizmann Istitute Irradiation Facility 60Co (1.1 and 1.3 MeV photons), 0.5-20 MHz

5. TRT Sector Prototype and FE 12 DTMROC (24 ASDBLR) = 192 channels 8 planes x 24 straws = 192 straws Web boards

6. Flex board WEB 1 WEB 2 Special web flap configuration with analog control Photon Source Straws sharing different web flaps (3 flaps per web) DTMROC (2 ASDBLRs) 16 straws ASDBLR (HV Group) Flex PCB

7. 60Co 60Co 1.1 MeV 1.3 MeV Sector Prototype 9.4 MHz Gamma Source 2.7 MHz 15.0 MHz 19.0 MHz 4.7 MHz 1.0 MHz Gamma Source Shielded (5 cm Lead) 0.5 MHz Irradiation Area

8. Weizmann Irradiation Facility

9. Weizmann Irradiation Facility

10. DAQ, Calibrations • DAQ and FE characterization: XTRT software • Random internal triggers (40 MHz) • All data taken with thresholds set in eV’s • Calibrations Low Threshold DAC/eV DAC offsets High Threshold DAC/eV DAC offsets

11. Occupancy Definitions • Occupancy • Ratio of events with at least one hit over total number of events (for either 1 or 3 beam crosses) • Rates calculated from occupancies • Hits • LT hits: at least one low threshold bit set • LE hits: at least one leading edge • HT hits: at least one high threshold bit set

12. Occupancies (%) 3 BC Rates (MHz) Noise Rate Noise Occupancy 169  221 kHz 1.3  1.7 % 250 eV 250 eV LE LT Noise Occupancies and Rates X5 GIF Noise Rate 1.0  1.1 % (3 BC) 130  143 kHz(3 BC) (200 eV)

13. X5 GIF Weizmann Low Threshold 250 eV Occupancies vs Rates No irradiation X5 GIF: 1.7%, 680 kHz (1 BC)

14. High Threshold 3 keV Occupancies vs Rates

15. Rates

16. HT LE LT Energy Spectrum Shapes Low Threshold Occupancies High Threshold Occupancies • Harder energy spectrum at low rates • Softer at high rates 1.0 MHz • Low threshold occupancies higher at low thresholds for low rates • Flat at high rates 15.0 MHz

17. 60Co Gamma Source 15.0 MHz 19.0 MHz Irradiation Area 60Co 9.4 MHz 4.7 MHz 2.7 MHz Gamma Source Shielded (5 cm Lead) High Rates (softer energy spectrum) 1.0 MHz Low Rates (harder energy spectrum) 0.5 MHz

18. 250 eV 250 eV 400 eV 400 eV Signal Width 0.5 MHz 9.4 MHz

19. GANT Simulation • Use GEANT TRT test-beam MC to simulate the photon irradiation setup …thanks to Eisabeta, Fred, and Sergei

20. GEANT Simple Simulation 1.3 MeV  1.3 MeV  (shield) 1 MeV e- dE/dx

21. Test-beam Energy Spectrums 20 GeV electrons 20 GeV pions

22. Energy Spectrum Shapes 0.5 MHz 1.0 MHz Low Threshold 250 eV 2.7 MHz 4.7 MHz

23. Energy Spectrum Shapes 0.5 MHz 1.0 MHz Low Threshold 300 eV 2.7 MHz 4.7 MHz

24. Cross-Talk • Conductive coupling in the straws which share the same decoupling capacitor • Parasitic capacitive coupling at the end of the straws Ccoupl Cblock Riso Signal return HV + filter • Internal channel-to-channel cross-talk of the analog ASDBLR chip • Cross-talk through connecting traces on the flex-rigid boards and web board

25. High Threshold Hit Required on a Trigger Straw Straws sharing the same HV group Straws sharing the same web flap Occupancy Cross-Talk

26. ASDBLR HVgroup Web flap Away straws Occupancy Cross-Talk 5 keV 7 keV 2.7–2.1 increase 3.1–2.9 increase 11 keV 4.0–2.9 increase 0.5 MHz

27. Occupancy Cross-Talk 5 keV 3 keV 2.0–1.8 increase 1.0 MHz 2.0–1.4 increase 9 keV 2.4–1.3 increase 11 keV 2.6–1.3 increase

28. Occupancy Cross-Talk 3 keV 5 keV 1.3–1.2 increase 2.7 MHz 1.4 increase 9 keV 11 keV 1.6–1.1 increase 1.6–1.1 increase

29. Occupancy Cross-Talk 400 eV 250 eV 0.5 MHz 170-200% (250 eV) 140-190% (400 eV) 250 eV 400 eV 2.7 MHz 30-60% (250 eV) 20-50% (400 eV)

30. ASDBLR HVgroup Web flap HT Occupancy Cross-Talk No Cross-Talk in High Threshold Occupancies

31. Use calibrated internal test pulse signals 15 DAC  600 eV (50% Occ) 21 DAC  1 keV (50% Occ) Test pulse signals adjusted in time to arrive always at the same position (middle BC) Hit efficiency (per channel): fraction of events with a LE hit over total number of events Hit Detection Efficiencies

32. Hit Detection Efficiencies 15.0 MHz 1.0 MHz 4.7 MHz 19.0 MHz 2.7 MHz 9.4 MHz

33. 250 eV 300 eV 400 eV 1000 eV Time Occupancies • Time occupancies are defined as the ratio between time occupied by LE’s in 3 BC’s over total time 15.0 MHz 1.0 MHz

34. 250 eV 300 eV 400 eV 600 eV Hit Detection Efficiencies TP = 600 eV TP = 1000 eV

35. Hit Detection Efficiencies Test-Beam Drift-Time Efficiency

36. Hit Efficiencies (Summary)

37. Noise ocupancies (250 eV, middle BC) 0.5% 170 kHz Occupancies under irradiation (250 eV, middle BC) 3.6% 1.4 MHz (data)  0.5 MHz (monitor straw) 13.0%  5.2 MHz (data)  4.7 MHz (monitor straw) 26.3%  10.5 MHz (data)  15.0 MHz (monitor straw) Summary (part 1/3) • Background energy shapes similar to those from past electron test-beams for most of the data. Harder energy spectrums for data taken at low rates (0.5-1.0 MHz)

38. Summary (2/3) • Hit detection efficiencies • Up to 5 MHz  > 90% • Rapid decrease for > 5 MHz • Occupancy cross-talk • Confirm results from previous X5 GIF test • Low threshold occupancies (250 eV) 0.5 MHz  170% - 200% for 5 - 11 keV signals 1.0 MHz  100% - 160% for 5 - 11 keV signals 2.7 MHz  30% - 60% for 5 - 11 keV signals • High threshold occupancies slightly affected (<10%)

39. Thanks….. Weizmann Institute Of Science • George Mikenberg • Meir Shoa • Staff irradiation unit • Gideon Ben Moshe • Shaul Ovadya