1. MuTr HV Optimization RIKEN/RBRC Itaru Nakagawa 1

2. Goal Find out HV to achieve Noise RMS/MIP peak (N/S) = 1%. Gain can be similar to chambers, but noise distributions are unique from chamber to chamber. Historically MuTR has been operated with only three HV settings (St1=1875V, St2=1900V, St3=1925V) Vary HV channel by channel basis to set N/S ~ 1%. 2

3. Cosmic Data Taking HV Setting# Triggers -30 V2M Nominal (St1:1875V, St2:1900V, St3:1925V)3M +15V3M +30V3M +50V3M Dedicated Measurements : Dec.23 ~ Jan. 11 MuIDLL1 N1D||S1D trigger : 60Hz ~ 120Hz Work area: phnxmutr@va020:/data2/SubSystems/phnxmutr/itaru/MipAna README for instruction Event Selection: 1.Peak Strip ADC of Cluster. 2.No track required. 3

4. North Arm 4

5. Station-1 Oct.1 Oct.2 Oct.3 Oct.4 Oct.5 Oct.6 Oct.7 Oct.8 Gap-1 Gap-2 Gap-3 5

6. Station-2 Oct.1 Oct.2 Oct.3 Oct.4 Oct.5 Oct.6 Oct.7 Oct.8 Gap-1 Gap-2 Gap-3 6

7. Station-3 Oct.1 Oct.2 Oct.3 Oct.4 Oct.5 Oct.6 Oct.7 Oct.8 Gap-1 Gap-2 7

8. MIP Peak Positions @ Nominal HV oct1 oct2 oct3 oct4 oct5 oct6 oct7oct8 gap1gap2gap3 St-1 St-2 St-3 8

9. Pedestal RMS (North Station-1) 9

10. Plane Averaged Pedestal RMS [ch] oct1 oct2 oct3 oct4 oct5 oct6 oct7oct8 St-1 St-2 St-3 10

11. Noise RMS/MIP Peak @ Nominal HV St-1 St-2 St-3 11

12. N/S.vs Operation Voltage Noise RMS / MIP Peak ADC [%] St-1 St-2 St-3 Nominal + Additional Voltage [V] Linear Fit nominal +15V +30V +50V -30V N/S : 2% -> 1% Needs additional 110V N/S : 2% -> 1% Needs additional 110V 12

13. N/S~1% Required Voltage : Nominal + ?V St-1 St-2 St-3 +50V limit St-2, St-3 planes are averaged over common HV chain 13

14. South Arm 14

15. Station-1 Oct.1 Oct.2 Oct.3 Oct.4 Oct.5 Oct.6 Oct.7 Oct.8 Gap-1 Gap-2 Gap-3 15

16. Station-2 Oct.1 Oct.2 Oct.3 Oct.4 Oct.5 Oct.6 Oct.7 Oct.8 Gap-1 Gap-2 Gap-3 16

17. Station-3 Oct.1 Oct.2 Oct.3 Oct.4 Oct.5 Oct.6 Oct.7 Oct.8 Gap-1 Gap-2 17

18. MIP Peak Positions @ Nominal HV oct1 oct2 oct3 oct4 oct5 oct6 oct7oct8 gap1gap2gap3 St-1 St-2 St-3 18

19. Plane Averaged Pedestal RMS oct1 oct2 oct3 oct4 oct5 oct6 oct7oct8 St-1 St-2 St-3 19

20. Noise RMS/MIP Peak @ Nominal HV St-1 St-2 St-3 20

21. N/S.vs Operation Voltage Noise RMS / MIP Peak ADC [%] St-1 St-2 St-3 Nominal + Additional Voltage [V] Linear Fit nominal +15V +30V +50V -30V 21

22. N/S~1% Suggested Voltage : Nominal + ?V St-1 St-2 St-3 22

23. HV Configuration File phoncs@va011:~/hv_stuff/ hvcontrol_MutrN(S) phoncs@va011:~/hv_stuff/ hvcontrol_MutrN(S) Copy & paste 23

24. Study From Run9 Run09Run11 DataBeamCosmic HV ScanNominal, +25V, +50V-30V, Nominal, +15V, +30V, +50V N/S1.5%1.0% 24

25. HV Set to be N/S ~ 1.5% (North) 25

26. Cosmic vs Beam (Absolute) 26

27. SN vs HV (North) nominal +25V +50V 27

28. Conclusion MuTr Gain.vs HV were evaluated using HV scan data with cosmic HVs are optimized to set N/S to be 1%. New HV will be configured soon. Will confirm N/S really comes as it desired with further data taking. Need to confirm with beam data as well. 28