Vacuum chamber

Done

• Remove WP-1250 NEG cartridges
• Remove posts for woven metal screen and replace with something suitable for high vacuum
• Add (tack weld?) fixtures to the vacuum chamber for S&A tooling
• Send vacuum chamber to S&A for fiducial (locate top flange, and anode flange with repost to chamber z-axis.
• Clean vacuum chamber (wipe off with iso-propanol, removed foreign objects, etc)
• Consider replacing the WP-1250 NEG cartridges with modern UHV 1400 NEG wafer modules (~12 week delivery)
  • If using UHV 1400 NEG wafer modules, no screen is necessary
  • Marcy to calculate how many UHV 1400 NEG wafer modules are needed, based on this, we'll develop a scheme to mount them. No need for a shield screen if e go with this modern NEG wafer modules. Need to figure out how to win them inside the vacuum chamber, and likely built a new power supply.
• If the old WP-1250 modules stay:
  • Bubba to finish new woven metal screen
  • Devise a better method to hold the screen in place
  • Devise a reliable method to prevent electrical short in the NEG cartridges electrical connections for full activation with current
• Re-install extractor gauge

vacuum qualification of chamber

• Gun chamber cleaned, blown down with ionized nitrogen
• UHV1400 pumps installed and connected to feedthrough
• First bake: 48 hours at 250C. No NEG activation. Leak in extractor gauge opened on ramp down
• Second bake: 24 hours at 250C after vent for extractor swap. P vs. T data taken for ~2 weeks
• Third bake: 48 hours at 250C, NEG activated for 1 hour at 500C while chamber at 200C. Vacuum tests underway 31march2022

Steps for completion

• Finish vacuum qualification (~April 15)
• Fabricate and install shield screen
  • Finalize design (April 8)
  • Order parts: standoffs, more screen, shimstock strips? (April 8)
  • clean and heat treat materials (April 18 or 25)
  • install screen (April 25 or May 2)
• Send gun assembly to clean room for inversion, nitrogen blow-down. week of May 2?
• Install spider and anode, align
• Install electrode, align

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