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

• leak test large grain Nb cathode/ceramic/flange assembly : << carlos' logbook entry goes here >>
• S&A jobs (will walk with Chris Gould 4/7 @ 9am UITF)

fiducialize Nb cathode to 10" flange (old method glued fiducials)

(maybe) fiducialize existing 10" flange to HV chamber

fiducialize anode to HV chamber

align cathode to anode

align LM to cathode (after venting depo)

align HV to chamber Y

• re-align laser for retro-reflection
• vent HV chamber, remove cathode electrode, searching for puck tab

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
• Galling reduced by addition of Mn and Si

• Nitronic 60 data sheet (Nitronic trademark AK Steel)
• 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