Apr 10 2024

Updates

• Marcy and Carlos are updating the schedule for removing the solenoid NEG tube, adding a viewport with pump out port to the upstream of the gun valve with the goal to help Shukui and S&A to se the laser launch for laser retro-reflection after the gun is installed under rough vacuum.
• Many thanks to Alicia, Yan, Max and Riad for sending me their ATLis for injector beam commissioning plans. I am adding those to the schedule as well.
• The Teflon Rod, as well as S&S crew will be ready by Thursday to continue laser retro-reflection checks with the R30-3 gun in the clean room.
• We received one more electrode front end sample from the machine shop with better surface finish. Jessica polished it in the tumbler with our procedure and the results is fantastic. One can see the typical orange peel surface characteristic of SS polished with diamond paste. No machining marks are seen after polishing. See attached pics. The electrode on the righ is the one starting off with better surface finish compared to the left one.
• The four electrode front end pieces made with high quality steel have been manufactured. 2 option A (16-30 deg) and 2 option B (16-60 deg). Jessica has been given full time use of the tumbler by SRF and she will have these polished by the end of the week.
• Polishing procedure followed on the sample piece:
  • After machining to the best machine surface possible (specified in the drawing as 16 micro-inches), use 400 grit wet sand with water and then 600 grit wet sand.
  • Finish using the Hyprez Diamond Polishing Compound with water as well.
  • After applying the the compound with Alpha Wipes, proceeded to buff out the finish using a clean Alpha wipe followed by a Microfiber cloth until all the compound is removed.
  • This process takes about 20-30 min to complete with the Lathe spindle around 800 rpm.
  • The piece will look very shiny, but the machining marks are still visible. To complete the polishing procedure to render a surface finish comparable to that obtained with manual polishing with diamond paste:
  • Place piece in tumbler bucket filled to 75% capacity with green 9/16" cones (5500-60040 9/16 green cones from Mass Finishing). Fill to the line with water and ten once of TS compound per gallon of water. Tumble for 2 hours.
  • Repeat with red 1/2" cones (5500-6310 from Mass Finishing) for 2 hours.
  • Clean sample with water, dry and repeat with crushed corncob 5501-3002 (coarse) from Mass Finishing for 2 hours.

• Pictures: The right hand size shows the sample piece after following the procedure described above. The piece on the left is a sample piece machined to 16 micro-inches surface finish without the additional machine shop polishing and after applying the tumbler procedure. Notice how the machining marks are not removed by the tumbling procedure without the additional pre-polishing procedure done in the machine shop.
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Schedule

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