1. 1 Vacuum Pressure Calculations

2. 2 Vaccalc The program vaccalc was used for all calculations. The program required three pieces of information for each chamber: pumping, conductance, and outgassing. Using the given information, the program calculates the pressure at any point along the entire tube.

3. 3 Chamber Design HER downstream LER upstream LER downstream HER upstream Support chamber Q5 NEG 66.114 m 69.33 m ST plot plot 12 3 4 56

4. 4 Assumptions Bertollini’s numbers on outgassing were true. 2000 (l/s)/m pumping for all NEG pumps with B or C screens. 1000 (l/s)/m pumping for all NEG pumps with A or D screens 1000 (l/s)/m pumping for all ion pumps (150 l/s pump over 0.15 m)

5. 5 Data Conductance remains a constant throughout the LER tubes. Lengths were taken from drawings and tables. This is a work in progress, making it difficult to draw final conclusions from the plots.

6. 6 Cases Baseline Design –No Radial Pumps No C Pumps –No Upstream Q4 Pump No Q4 pump with Ion pump LER Q5 not pumping LER Q5 outgassing No Q4 pump with Ion pump and frangible pump LER Q5 not pumping with Frangible Link Pump LER Q5 outgassing with Frangible Link Pump No C Pumps –Q4 and Q5 outgassing –No Q4 and Q5 outgassing

7. 7 Baseline Design (Support Tube)

8. 8 Upstream HER

9. 9 Upstream LER

10. 10 Downstream HER

11. 11 Downstream LER

12. 12 No radial pumps

13. 13 No C Pumps Upstream (support tube)

14. 14 Upstream LER

15. 15 No Upstream Q4 Pump (support tube)

16. 16 Upstream LER

17. 17 No Q4 pump with ion pump

18. 18 Q5 not pumping

19. 19 Q5 Outgassing

20. 20 No Q4 pump with ion and frangible pump

21. 21 Q5 not pumping with Frangible Link Pump

22. 22 Q5 outgassing with Frangible Link Pump

23. 23 No C Pumps Upstream (support tube)

24. 24 Upstream LER

25. 25 Q4 and HER Q5 outgassing (support tube)

26. 26 Upstream HER

27. 27 Upstream LER

28. 28 No Q4 and HER Q5 outgassing (support tube)

29. 29 Upstream HER

30. 30 Upstream LER

31. 31 Next Steps Test other possible combinations Finish the HER –Upstream –Downstream Recalculate outgassing numbers Check pump speed numbers –screen conductances