1. Antiproton Lens Replacement (Unfortunately Part 2) Keith Gollwitzer Antiproton Source Department for the Experts and Mechanical Support Department Target Station Group Thanks also to the Radiation Technicians of AD ES&H

2. Fri Saturday 00:00 Sunday Monday Disconnected from power supply HiPot of module + lens/transformer find 1.7μA @ 3000V !! Vault stripline HiPot is also fine Connect power supply to pulse … ground fault Problem getting power supply to turn on with dummy load Movement of control cards about get supply to pulse with Back to original configuration…able to pulse dummy load Another HiPot of module + lens/transformer shows good Power supply re-connected to lens/transformer … Pulsing!!! Will gradually bring up to operation gradient and then put rest of shielding blocks back. Should be stacking within a few hours Last Slide From Last Week

3. Mon after AEM meeting Started at 17:15 with low intensity beam Did nominal orbit position scans and started increasing beam intensity 18:08 water conductivity interlock trip Looks like Lithium leak into cooling water

4. Tue 0700 to Wed 0130 Replacement of 10mm-2 with lens 32 went well Lower gradient lens Ran 20 minutes of beam and then conductivity interlock trip Looks like Lithium leak into cooling water Two for two!?!?!?! Investigate further with beam Noted that conductivity also increases with lens off and beam pulse but not when pulsing lens with no beam Not look like Lithium lens leak?

6. Wed 0700 to Wed 2200 Checked conductivity probes with calibrated solution Replaced one of two probe+meter (twice) Changed DI cartridge of water system Further beam studies Concluded either Lithium leak or other contamination Set conservative lens gradient and beam intensity for stacking and watched for conductivity to be “cleaned-up”

7. Thu and Fri Continue to stack with conservative running conditions while “contamination” clean-up Could still be Lithium leak Held a small debriefing of lens change-outs Realization of possible ethanol alcohol introduced during Saturday’s separation of the stuck module water tube from the 10mm-2 lens/transformer brass block water connection. Estimated quantity of possible contaminate Performed test of intentionally adding ethanol alcohol to system and saw response as seen earlier Returning slowly to normal operating conditions

8. Other Lenses 10mm-2 is believed to be good due to Lens 32 running 10mm-1 and 10mm-3 may be recoverable (two weeks for the latter to be recovered?) Lens 23 already has 9.5M pulses Lens 30 has sputtered material on it Lens 4 has to run at even lower gradient New lenses Estimated for complete lens/transformer assembly (taking into account furloughs, vacation, material, additional manpower): Late April Mid-June, Late summer/Fall (2)

9. Last Week’s Slides

10. Fri Saturday 00:00 Sunday Monday Initial Failure at 18:40 Friday Determined problem in vault and not the power supply Appeared as open circuit

11. Fri Saturday 00:00 Sunday Monday Lens change-out crew arrive, open vault, remove module with lens/transformer assembly and discover problem

12. Fri Saturday 00:00 Sunday Monday

13. Fri Saturday 00:00 Sunday Monday Strip-line failure (1 st time seen) Moved on to installing previously used 10mm-2 lens (high gradient) 10mm-2 history: Used 1 week in May07 before water leak caused transformer to fail Lens installed in a new transformer during shutdown07 Used Oct-Dec07 During Target change-out photograph showed tie-rod working its way out Tie-rod repaired early Jan08

14. Fri Saturday 00:00 Sunday Monday 10mm-2 lens put upon module and connections made Failed water circuit test (pressurized gas) 2 pairs of 8ft tubes run though module (provide water cooling for lens and transformer) connect to “brass block” (patch panel) of lens/transformer assembly. Depending upon brass block, order of connection can make difference of leak Could not disconnect one water tube

16. Fri Saturday 00:00 Sunday Monday Meeting to discuss options: Repair 10mm-2 brass block – water tube connection vs installing low gradient lens 32 Low gradient means a 12-15% loss of yield 8days low gradient = 7days high gradient Repair plan was chosen

17. Fri Saturday 00:00 Sunday Monday Water tube was forcibly removed from brass block 10mm-2 lens/transformer assembly un-installed from module New water tube installed on module New brass block was taken from another low gradient lens Brass block swap-out performed on 10mm-2 Re-install 10mm-2 lens/transformer assembly to module Pressurize gas test - still leak 10mm-2 lens/transformer assembly un-installed from module Determine leak on connection of line into lens -- tightened

18. Fri Saturday 00:00 Sunday Monday Upon moving lens/transformer assembly to prepare for re- connection to module, hit a water line Replaced water line Reconnect lens/transformer assembly to module Passed water circuit test!! HiPot of module + lens/transformer find 1mA @ 1500V New lens are <1μA @ 3000V Earlier HiPot of 10mm-2 was reasonable Experts decided to install into vault and pulse at low setting to see if can change HiPot Power supply trip on load overcurrent

19. Fri Saturday 00:00 Sunday Monday Disconnected from power supply HiPot of module + lens/transformer find 1.7μA @ 3000V !! Vault stripline HiPot is also fine Connect power supply to pulse … ground fault Problem getting power supply to turn on with dummy load Movement of control cards about get supply to pulse with Back to original configuration…able to pulse dummy load Another HiPot of module + lens/transformer shows good Power supply re-connected to lens/transformer … Pulsing!!! Will gradually bring up to operation gradient and then put rest of shielding blocks back. Should be stacking within a few hours