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How-to Clean the Duoplasmatron

Disassembly Instructions

1. Put Al-foil on working space; get gloves and Kimwipes.
2. Close Cs-source valve (EP13), close PBMF-valve (VM9, manual), close Main Isolation Valve (VM1 manual). Close oxygen-tank valves (3 - 2 on tank and 1 on little tank).
3. Vent DP = go to Synoptic Vacuum VI
   1. select manual
   2. close EP15 and EP14
   3. stop TP 4 and TP 5
   4. turn off CC1B and CC2B
   5. wait 3 min
   6. open EP 16 (close when step 9 completed)
4. Shut off primary HV (both switches on the chassis).
5. Remove DP metal covers (two sides, top and bottom) and teflon sheets.
6. Remove coil connection on DP (white wires, left and right).
7. Remove cathode HV lead (DP back, white tubing) and anode HV lead (DP left).
8. Unplug freon pump. Use 14mm wrench to discconect DP from freon cooling circuit (hold with 17mm wrench - start with the incoming freon tubing); do cathode cooling in back first, then underneath DP, collect freon in beaker.
9. Unscrew oxygen leak valve, wrap in Al-foil. (remove pressure clips, top first then bottom, let the bottom clip hang) Close EP16 after the oxygen leak valve is removed.
10. Use 10mm wrench to loosen bolts around front of DP and remove DP (do the top bolt last). Cover extraction lens with Al-foil. Keep DP in upright position. (Use a lint-free swab and methanol to clean around where the O-ring comes off)
11. Disassemble DP electrodes. First remove cathode (3 screws with teflon spacers), then remove teflon sheet. Collect loose NiO powder, and unscrew oxygen inlet screw in cathode (FIG. 1, can be reused). Remove cathode (has to be dumped).
12. Use screwdriver to unscrew Z-electrode. Remove teflon spacers and sheets.
13. Disassemble intermediate anode (FIG 2)
14. Turn DP and unscrew holding ring for anode. Remove anode. Check if aperture is tight. If worn out, replace (FIG 3)

Cleaning Instructions

• Teflon: clean with ethanol
• Metal parts (anode - make sure hole is clean, intermediate anode, oxygen inlet): let it soak in ultrasonic bath with soapy water (at least 30 min), metal polish, again ultrasonic bath (soapy water, 15 min). Do not use any acids. Rinse with dest. H2O (15 min), acetone (15 min), ethanol (15 min).
• Viton-rings: rub with ethanol, eventually use a little vacuum grease

Assembly Instructions

1. Intermediate anode: long thread with cap, short thread in Z-electrode (!).
2. Put teflon sheet between DP and Z-electrode, insert teflon spacers and tighten it loosely with two screws (must move). (UCLA: washers must be put in when reassembled on probe).
3. Assemble cathode by screwing in oxygen inlet. Insert 3 teflon spacers, teflon ring and viton ring and put in cathode. Tighten 3 holding screws.
4. Check if aperture is clean and plane.
5. Screw in anode until it meets the intermediate anode. Then unsrew 2 turns (2 mm distance). Screw in holding ring and tighten.
6. Assembly on DP: check viton ring on extraction lens part, set DP on bolts, check for leads inbetween and tighten with 10 mm screws. Reassemble electric connections and freon cooling. Get oxygen leak valve (check arrow indicating oxygen flow direction: must point downwards) and tighten with wing nuts (wings should point towards PBMF). Reassemble teflon sheets and metal cover.
7. Pump DUO:
   1. Make sure EP 16 is closed
   2. Close EP4
   3. Open EP14, wait for TC2A to reach <1E-2
   4. Open EP15
   5. Start TP4, TP5
   6. after TP4 and TP5 are up to speed (green LEDS on), turn on CC1B, CC2B
   7. Open EP4
8. Pump O₂ line (1st pump air, then open and close oxygen tank and pump again).
9. This is also a good time to drain the air compressor.