1. IR 2 Vacuum Update M. Sullivan for PEP-II team For the 2e34 meeting of Feb. 15, 2006

2. Orientation A look at some of the gas squirt events NEG heating events Summary

3. Typical event from Feb 5th LER HER 2.29 1364 122 LER frangible link Detector 0 2.25 993 Support tube end bellows NEG pump Backward Q2 NEG Forward Q2 NEG 00.08

4. Another typical event from Feb 5th LER HER 0.54 1653 27 LER frangible link Detector 0 0.82 198 Support tube end bellows NEG pump Backward Q2 NEG Forward Q2 NEG 00.07 Small numbers have larger baseline subtraction errors

5. Vacuum events with single ring LER on Sat. morning Feb 11 th Vacuum spike Big vacuum spike 100 nTorr squirt

6. Vacuum spike event at 11:50 on Feb 11th 2300 mA in LER only LER HER 2.44 7950 16.9 LER frangible link Detector 0.34 4.32 1413 Support tube end bellows NEG pump Backward Q2 NEG Forward Q2 NEG 00.60

7. Squirt event at 11:51 LER HER 0 334 0.29 LER frangible link Detector 0 0 1171 Support tube end bellows NEG pump Backward Q2 NEG Forward Q2 NEG 00.07

8. The highest vacuum spike event at 11:57 on Feb 11 th 2446 mA in LER only LER HER 17.2 3830 225 LER frangible link Detector 1.16 9.2 3672 Support tube end bellows NEG pump Backward Q2 NEG Forward Q2 NEG 02.05

9. Big air event when we opened a valve LER HER 240 0 3440 14 LER frangible link Detector 24 81 1360000 Support tube end bellows 479 NEG pump Backward Q2 NEG Forward Q2 NEG

10. 10000 nTorr squirt (no beam) LER HER 1.01 0 10.1 LER frangible link Detector 0.19 0.61 9125 Support tube end bellows NEG pump Backward Q2 NEG Forward Q2 NEG 0.071.57 Argues that the 3027 gauge sees too much pressure

11. 10000 nTorr squirt (with beam) LER HER 1.01 0 10.3 LER frangible link Detector 0.19 0.61 8720 Support tube end bellows NEG pump Backward Q2 NEG Forward Q2 NEG 0.951.29 Argues that the 3027 gauge sees too much pressure

12. Heating forward Q2 NEG pump 60 nTorr

13. Forward Q2 NEG heating with beam LER HER 0.38 72 5.1 LER frangible link Detector 0.08 8.9 60 Support tube end bellows NEG pump Backward Q2 NEG Forward Q2 NEG 00 The 8020 pump sees too much pressure

14. Heating up the forward Q2 NEG Luminosity went down when we added gas. The decrease is noticeable at a pressure of about 30 nTorr Traced to the HER vertical spot size increasing. Luminosity restored as the pressure goes down.

15. Heating up HER Q5 NEG (8020) on the forward side of the detector Detector backgrounds remain low 380 nTorr

16. Heating of 8020 NEG today -- Feb 15 th LER HER 0.42 56 2.1 LER frangible link Detector 0 380 20.6 Support tube end bellows NEG pump Backward Q2 NEG Forward Q2 NEG 00.29 HER 8020 NEG

17. When we heated up the HER forward side NEG (8020) we saw the HER vertical spot size increase and the lumi decrease when the gas pressure got up to about 30 nTorr The gas is predominately H2 As the gas pressure increased further the HER vertical spot size got smaller again and the HER went horizontally unstable We lost the beams on a radiation abort, however there was no vacuum spike and the pressure was coming down since we had turned off the heater about 2 min earlier

18. Summary The pressure squirts argue the source is closer to the IP from the 3027 gauge because the pressure seen at the 3027 gauge is too high The heating of the forward Q2 NEG and the HER 8020 NEG argue the vacuum spikes are between the detector and the Q2 NEG (could be in the location of the Q2 NEG) Unfortunately not yet able to rule out the support tube