1. Detector Stability Analysis Using MoRI Data David Barnhill UCLA

2. Motivation Monitor detector performance of key quantities: –Anode and Dynode Baselines –VEM Area and Area/Peak –Dynode Anode ratio Detect any peculiar behavior as a function of temperature and/or time Check Quality Assurance specifications suggested in November meeting

3. Method We analyzed 188 preproduction tanks from January to February this year We used LS Calibration Data (MoRI) We analyzed RMS over this period for Anode and Dynode baselines and RMS/Mean for Dynode/Anode, VEM Area, and Area/Peak for each tank We also looked at behavior over time and as a function of temperature * In the next slides: –Then = September – October 2003 –Now = January – February 2004

4. Typical Baselines vs. Time Then Now

5. Anode Baseline RMS Then Now 45 over 2 channel RMS 15 are due to pedestal readjustments 30 out of spec – 5.3% 3 out of spec – 2.2%

6. Dynode Baseline RMS Then Now 32 over 2 channel RMS 8 are due to pedestal readjustments 24 out of spec – 4.3% 1 out of spec – 0.7%

7. Baseline RMS vs. Station ID Anode Dynode

8. Baseline Problems All 6 channels => FE problems? (~10 tanks)

9. Temperature Coefficients - Baselines Anode Then Now

10. Temperature Coefficients - Baselines Dynode Now Then

11. Typical LS VEM vs. Time and Temperature Then

12. Typical LS VEM vs. Time and Temperature Now

13. VEM Area vs. Station ID

14. LS VEM Area Then Now 29 over 5% 11 due to recalib. 18 out of spec – 3.2% 6 out of spec – 4.4%

15. Tank 205 (Mage) VEM Area PMT 1 seems to be decaying Then Now

16. Temperature – LS VEM Area LS VEM Area Then Now

17. Temperature Problem As documented in Bugzilla: –http://bugzilla.auger.org.ar/ There is a known problem with temperature causing jumps in certain quantities –Tanks 116, 147 and possible 158 and 167 Problem is known, but cause and solution are unknown

18. Tank 147 VEM Area ThenNow

19. Tank 116 VEM Area ThenNow

20. New Problems

21. Typical LS VEM Area/Peak vs. Time ThenNow

22. Area/Peak vs. Station ID

23. LS VEM Area/Peak Then Now All 3 PMTs in each tank affected 35 over 5% -> 6.2% 2 out of spec – 1.5%

24. Temperature - LS VEM Area/Peak Then Now

25. Typical Dynode/Anode Ratio ThenNow

26. Dynode/Anode vs. Station ID

27. Dynode/Anode Then Now 8 out of spec -> 1.4% 7 out of spec -> 5.1%

28. Dynode/Anode Problems

29. Temperature – Dynode Anode Ratio Then Now

30. Tank 128 (Vatly) Dynode/Anode No entries in bugzilla ThenNow

31. Dynode/Anode Spiky Behavior - Gone ThenNow

32. Quality Assurance Specifications NOW THEN

33. Stability Conclusions Pedestals: –All due to ~10 tanks with varying pedestals on all 6 channels Area/Peak: –All 3 PMTs in a tank affected when one goes bad ~13 tanks –Statistics looks bad, but roughly divide 6.2% by 3 = ~2% problem Dynode Anode ratio is more consistent and stable, 3 PMTs with bad D/A problem only VEM Area –Temperature correlation issues ~7 PMTs –Other problems ~3 PMTs Tanks with PMTs failing multiple specs: –102, 193, 214, 262

34. PE at 1 st Dynode

35. PE at 1 st Dynode vs. Gain