Antiproton Lens Replacement Keith Gollwitzer Antiproton Source Department for the Experts and Mechanical Support Department Target Station Group

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

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

Fri Saturday 00:00 Sunday Monday

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

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

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

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

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 1500V New lens are 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

Fri Saturday 00:00 Sunday Monday Disconnected from power supply HiPot of module + lens/transformer find 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