March 31, 2017 - 200kV gun upgrade meeting

New action items

Electrode/insulator design/fabrication

• Assess fields to vacuum chamber, modified shed radius

Gabriel assess shed radius suggested by Danny, now => model 2.5 (w/ cross view) media:170328_Gabriel.pdf

• S&A insulator measurements

From Danny: S&A has given me the data in two batches. the first media:DT_L1782-1.pdf has to do with most of the dimensions, the second the contour  of the ceramic. i've looked at the first batch, but not the second yet. here's what i  think so far. hopefully, i'll look at the other data this afternoon. In summary, it's all acceptable.
.
a) both black ceramics are very close to being identical.
b) both ceramics are all within tolerance of the model and drawings.
c) the ceramic keyway is not perpendicular to the flange leak check groove as it should be, but it will still work. the leak check grooves in the chamber flange  will not align with the leak check grooves on the ceramic flange. the keyway on the  ceramic is off .6 degrees. fortunately the slots in the flange allow for +/- 1  degree rotation, but we used up some misalignment allowance that we didn't need to.
d) the concentricity and perpendicularity of the end of the ceramic to the flange is within .006" and .2 degrees.
e) the distance of the end of the ceramic to the flange face is .005" short.
f) all the dimensions are good enough for the adjustment we have in the anode.
g) the data shows the 1.00" diameter end of the ceramic is too large by .001"-002". if so, it may not fit into the electrode. i went and measured it with some  micrometers and believe it to be within tolerance.
h) i'm not sure of the importance of the location of the triple point. it  measures .006" high and .003" bigger radially. if i remember from previous discussions, that was not a big deal. can someone confirm that?

• ME design for shop ... goal is end of March !!!

a) Addressed a) correct shape for chamber (ball vs. tube), material (SS types, Nb), gradients for (triple point, insulator, chamber/NEG, cathode/anode), checked dimensions, resolved single part w/ new internal puck holder
b) Have complete due diligence, time to fabricate, differences between design/reality will be small/manageable

• Then ... vacuum fire electrode 900C, barrel polish, assemble to insulator
• Status of parts

a) Alumina ceramic bushing holder ready from shop media:170330_bushing.pdf
b) Ordered two centering ceramics - 4-6 weeks

Vacuum chamber/considerations

• Retain leak valve, add right angle valve through first bake, at least
• Retain electrical isolation and NEG activation at 100C
• Pick up ceramics, blow out NEG

Gun2 NEG Tube

• BPM discussion w/ Musson occurred on Monday, considerations:

a) Antenna : stripline or wire (mini or weld) media:170327_stripline.pdf
b) Position and orientation of antenna v. can for transmission line, length of antenna v. energy
c) NEG coat surfaces of pipe, not can? TBD

• Met in tunnel to develop first pass ME design Logbook pic/layout of the existing Gun2 NEG

a) First iteration media:NEGTUBE_MARCH30.pdf
b) To keep the ratio the same between the antenna and the BPM wall to suit a 2.5" tube, the tube diameter of the BPM section will have to be about 5.50" O.D., so the conflat flange will be 8.00".
c) The two BPM spool pieces will be similar. the difference will be the  direction the antennae will be pointing.

Gun3 Removal

• Matt check with Willeke next week during JLEIC meeting Gun3
• Remove Gun3 table, rebuild 8" chamber w/ extractor, RGA, GP-100 on 80/20 stand, recoup Gun3 MFH solenoid

a) Planning for May
b) Marcy submitted ATLIS task for the job

Spellman HVPS update

• Time to get Mike Johnson started on Spellman at UITF?

a) John/Brad trying to communicate to Spellman w/ their software
b) Need old version of JAVA to get started