Vacuum chamber

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Revision as of 11:36, 31 March 2022 by Marcy (talk | contribs)
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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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