| Miniproposals | ||||||||||
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| Operators | |
| Session leader(s): | Brian Labombard |
| Physics operator(s): | Steve Wolfe |
| Engineering operator(s): | |
| Engineering Operator Run Comment |
| automatically entered by signon - please replace with real comment |
| Session Leader Plans |
| Physics Operators Plans |
| Entered: May 21 2007 05:56:26:430PM |
| Author: Steve Wolfe |
Physop plan for Tuesday, May 22, 2007 MP#475 Cryopump Startup SL: Labombard PO: wolfe We will be doing mostly NO PLASMA checkout of the cryopump system, with the possibility of running plasmas in the afternoon. Engineering Setup ------------------- Alternator and Machine cooldown for a 2:00PM Start (lockup no earlier than 1:30 PM). Run will end at 5:00PM. No overnight ECDC Power Systems as on 1070511001 Acoil: +Dtop -Dbot -Jtop +Jbot (standard) Hybrid enabled Gas setup: ---------- Fill B-Top with 6 psi D2 Hybrid enabled (PG4) fill B-side lower with 1 psi Ar Hybrid DISABLED (PG1) leave B-side upper as is Hybrid DISABLED (PG2) fill B-main (C-side) with 40 psi D2 Hybrid enabled (PG3) NINJA backfill with 25 PSI of D2. Enable the following gate valves and shutters, assuming no vacuum problems: ECE, VUV, Z-bolo shutters; Enable DNB gatevalve when requested by DNB operator. Torvac setup: Pumpstack gatevalves CLOSED in PULSE (close time tbd) ICRF: not required LH: not required Physop plan: ------------ Most of the day is expected to be spent on the No-power run section of the MP (Cool-down/Regen and pumping speed benchmarks). See SL_PLAN for details. If things go well, we will want to take a few plasma shots with the pump operating, as described under the C-Mod Run#1 section of the MP: LSN Discharges: load from 1070511025 seg2, set nl04=0.8e20 Run a few shots with the pump not at LHe temperature, then cool the pump to helium. May need to adjust pg4 puff for breakdown. We expect little pumping in this configuration, but this needs to be quantified. Demonstrate pumping and regen cycles with plasma (manual control). If we get this far: USN discharges: load from 1070511022 seg3, set nl04=0.8e20 This should be maximum pumping configuration. Run a reference shot with pump "off" if there's time, then cool it down and pump away. |
| Session Leader Summaries |
| Entered: May 22 2007 11:11:34:257PM |
| Author: Brian Labombard |
| Run Summary for 1070522 MP#475 ""Cryopump Startup"" -Plan- This miniproposal calls out five start-up phases for commissioning the upper divertor cryopump: Phase I - System Assembly and Checkout Phase II - Cool-down/Regeneration and Pumping Speed Benchmarks Phase III - Operation during C-Mod Discharge Phase IV - Effect of secondary separatrix on pumping throughput Phase V - Density control in H-mode discharges The goals for today's run were to finish Phase I, finish Phase II and if possible begin Phase III. A 'no-power run' was planned for the morning with free access to the cell. Then sometime in the afternoon we hoped to begin operation of the pump in C-Mod plasmas. -Result- Progess on Phase I came to a grinding halt yesterday evening when the ethernet-based PLC crate controller for the cryopump died (we have no spare!). Without PLC control, none of the cryopump's valves can be operated. So, we spent all of the morning scrambling around to get a borrowed crate controller from the gas-jet injection system operating on top of the igloo with some new optical fibers. This was very painful. We thought we had killed the controller until we realized that we hooked it up wrong. Finally, with PLC control obtained around 1:00 pm, we started checking out the cryopump's systems, hoping to flow LN2 and LHe for some initial gas-pumping benchmarks and then into plasmas. But again the hardware was not willing. We found a number of problems: a bad power supply, wiring glitch on the He exhaust pressure gauge. We did manage to purge the LN2 system and open it to the C-Mod sump. With the LN2 system on-line and most all the controls and valves operating, we began to test the LHe circuit. Bad news. Several leaks where found on the newly assembled helium exhaust system, including a bad solder joint and a large leak where some thermocouple wires penetrate a brass fitting. So we scrubbed plans for plasmas and proceeded to remove the leaky components to be fixed. We will be back for another go at it soon. |
| Physics Operator Summaries |
| Entered: May 22 2007 04:28:47:337PM |
| Author: Steve Wolfe |
Physop summary for Tuesday, May 22 MP#475 Cryopump startup SL: Labombard PO: wolfe After the PLC problem was fixed, and a 5V power supply replaced, and the wiring to the helium exhaust pressure gauge corrected, significant gas leaks were found in the helium circuit. One leak was identified at the helium pressure gauge. The big leak was finally located at an epoxied hole used for a thermocouple, and fixing that will require some disassembly. The run was called off at ~16:00. No shots, no plasmas, no fizzles. |
| Session Leader Comments |
| Physics Operator Comments | |||
| May 22 2007 01:19:28:430PM | Steve Wolfe | The PLC controller for the cryopump has been replaced using the one from gas jet. There still seem to be some sensors that are not reporting correctly, but these are being checked out. Once that's done, Brian will begin the non-plasma part of the run, starting with purge and cool-down. With a lot of luck we'll be running plasmas later this afternoon. | |
| May 22 2007 01:29:12:233PM | Steve Wolfe | Getting ready for plasma per the run plan (sort of): Load from 1070511022. Seg 3 off, seg 2 on. This is lower null, 8e19 In seg1, PG 4 from 15 to 20msec Confirm Br0 at -.003T, EF4 at -1335A Not that we're going to get to it, but copy the nl04 trace from seg2 to seg3 (the upper null) Load it Load at 22-May-2007 13:27:35.00 Open tree /home/wolfe/pcs_scratch -1 Open tree done | |
| Engineering Operator Comments | ||||
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