Spring 2021 - Rebuilding Photogun

HV chamber : Replace cathode electrode

• Electrodes

• "old" existing electrode here : https://wiki.jlab.org/ciswiki/index.php/CIS-ASY-R28-3
• "new" niobium electrode here : https://wiki.jlab.org/ciswiki/index.php/CIS-ASY-R28-1

LgGnNb leak check => done 4/8, Carlos leak tested complete assembly in 1137

S&A fiducialize =>

• Alignment Jobs in Cave

Walk job with Carlos & Chris => done 4/7

S&A perform an as-found of the Gun through Y chamber => media:210414_UITF_15degLine_Summary.xlsx

Matt's "Have-Want" summary pics media:210414_HaveWant.pptx

Decide if we want to run beam before venting => don't think so, agree at 4/15 UITF meeting

S&A will fiducialize upstream anode face in UITF

S&A will be able to help us align new schneedle where cathode will go

S&A will be able to align cathode to anode

S&A will be able to align cathode/anode combo on whatever line we want (thinking Y ports)

CIS follows up for puck in/out tests, and laser alignment

Depo chamber : Replace schneedle, fix pucks, opportunistic jobs

• Make (2) SS schneedle w/o silver plating, replace depo chamber silver plated schneedle media:ACC2003000-0219 schneedle.pdf

4/6 - Shop is fabricating two, trying to have one ready by 4/18

one from 316 or 316L SS and one from Nitronic 60 https://mis.jlab.org/mis/apps/job_request/mshop/view_request.cfm?request_id=330210&code=1

• Nitronic 60 data sheet (Nitronic trademark AK Steel)
• won't use this ... although probably not a problem, can be mildly magnetic Mir50 (Mir50 trademark ASC Steel)

• NF3 leak value => leave as-is
• align mask, fix w/ two set screws
• replace K source with Alvatec Sb source?
• Inspect and mic pucks against series 30 series dwg media:JL0047248 PUCK BODY REV A.pdf media:MoPuckMount.docx

Other jobs

• Re-align HV chamber before venting? => sent request to Gould
• (done) Repair stalk heater driver => https://logbooks.jlab.org/entry/3871902