| Miniproposals | ||||||||||
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| Operators | |
| Session leader(s): | Greg Wallace |
| Physics operator(s): | Ron Parker |
| Engineering operator(s): | Andy Pfeiffer,Ed Fitzgerald,Bill Parkin |
| Engineering Operator Run Comment |
| MP#473: LH check-out and initial operation MP#518: LH_B and LH_D NINJA C |
| Session Leader Plans |
| Entered: Jan 22 2008 01:10:37:733PM |
| Author: Greg Wallace |
| Session Leader plan for 1071214
Session Leader: G. Wallace Physics Operator: R. Parker This run will be a combination of MP's 473 (LH Conditioning) and 518 (LH NINJA Puffing). The gameplan is to start with MP473 in the morning, bringing up the power level slowly to greater than 700kW. Piggyback operation of the NINJA LH capillaries will also occur during the first part of the run. After bringing up the LH power level we will switch to MP 518. LH system setup: Phase shifters at 90 degrees current drive direction, 1.5mm behind LH limiter. Start at 40kV beam voltage. 500ms shot starting at 700ms. Plasma setup: Start with 1071207027. Overnight ECDC. Cryopump in afternoon. Shot Plan: Start with 500ms pulse at 50kW per klystron. Increase power each shot in 10kW/klystron incriments until arcing occurs. After an arc, reduce power by 50% then continue raising in 10kW incriments. Operate NINJA LH_B and LH_D capillaries in piggyback mode after LH turns off at 1.2 seconds. Start at 95torr plenum fill and look at local density increase at LH grill. Adjust pressure up and down to see effect of different gas rates. Switch to MP 518 at 1pm or 1MW net without arcs. Reduce power back to 20kW per klystron, 500ms pulse starting at 700ms. Set NINJA such that LH_B hits plasma at 900ms and LH_D hits plasma at 1100ms. Increase power in 10kW incriments, making sure we do not see flashes or breakdown in the waveguides. If possible, decrease programmed nl_04 to keep edge density near constant for good coupling. Gas puff rates may need to be adjusted if ionization increases with LH power level. Cryopump and upper null may be needed for density control if all goes well. |
| Physics Operators Plans |
| Entered: Dec 13 2007 07:06:08:967PM |
| Author: Ron Parker |
| Engineering setup for Friday 14 Dec 2007
MP#473: LH check-out and initial operation MP#518: LH_B and LH_D NINJA Capillary Testing SL: G. Wallace PO: R. Parker ECDC overnight in D2 and bake at 60 C. Stop ECDC by 7:00 am. Run will start at 09:00 and end at 17:00. Power systems as on 1071207027 A-coil configuration: +Dtop -Dbot -Jtop +Jbot; Enabled (standard configuration) 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) fill NINJA with 10 psi D2 INITIALLY DISABLED Enable the following gate valves and shutters, assuming no vacuum problems: ECE, VUV, Z-bolo (Do not enable DNB gate valve.) Torvac setup: gate valves open Specific diagnostics: standard set ------------------------------------------------------------------------------- ICRF Setup: Turned off for entire run LH Setup: Set launcher to 1.5mm behind LH limiter. Phase shifters set to 90 deg current drive direction. Start with 50 kW per klystron, 500 ms. DNB: no Cryopump: no ------------------------------------------------------------------------------- Run plan: Start with 1071207027 and go from there. Set Ip~750kA, nl_04~0.8e20, outer gap~1cm. |
| Session Leader Summaries |
| Entered: Dec 14 2007 05:03:43:977PM |
| Author: Greg Wallace |
| Session Leader Summary for 1071214
MP 473: Lower Hybrid Conditioning After starting at 280kW net on the first shot we quickly worked up to 710kW net power. We reduced the power after some arcing in the Jungle Gym (columns 3,9,15) at ~800kW and were able to come back up to 710kW. With the current amount of conditioning, 700kW seems to be a reliable level, compared to 650kW after last week. Hopefully with a few more days of conditioning we can bring that up a bit more. Unfortunately, both the LH system and Alcator had some major problems. Two shots were wasted when the klystrons on Cart 2 (and tube #4 from Cart 1) did not fire. It is possible that noise from the early runaways caused noise on the TPS rack that shut off power to those klystrons. After reliable plasma operation all morning, we had nothing but fizzles all afternoon. |
| Physics Operator Summaries |
| Entered: Dec 14 2007 04:51:51:363PM |
| Author: Ron Parker |
| Machine ran well through shot 21,then stopped running well and we got nothing but fizzles after shot 21 -- 11 fizzles in a row! Breakdown seemed normal on all these shots but current wouldn't pick up, suggestive of a dirty wall or perhaps a protrusion in machine. We did stop for 0.5 hour of ECDC and this may have made a slight an improvement but if so it was short lived.
There was one "event" during the run, namely the appearance of a 28 peak on the RGA between shots 18 and 19. This was unexplained, but there were two full length shots after that so it is not clear if this led to our difficulties. Once again, the LH nudged up to 800 kW, then tripped, so it seems that this might be the maximum power that we will be able to couple, at least on a routine basis. |
| Session Leader Comments | |||
| Dec 14 2007 09:21:21:610AM | 1071214002 | Greg Wallace | LH ran clean at 50kW per klystron, 275kW net. No afterglow on the LH camera. Next shot will be at 70kW per klystron. Reflections a bit high, near 30%, but then again density at the grill was pretty low <1e18 on top and bottom. |
| Dec 14 2007 09:58:54:203AM | 1071214003 | Greg Wallace | Clean shot at 70kW per klystron, 375kW net. No afterglow. Next shot will increase to 85kW per klystron. Coupling still not great but it'll do for now.
Strong non-thermal signature on the ECE(1.5 on Ch9). Still not much current drive visible on Vloop. nl_04 from 6.5->6e19. |
| Dec 14 2007 09:59:59:033AM | 1071214004 | Greg Wallace | LH is running like a top. Another clean shot, this time at 85kW per klystron, 450kW net. No signs of arcing nor afterglow. Next shot will be at 50kV beam voltage and 100kW per klystron.
Strong ECE nonthermal signal (1 on Ch9), although it takes a dip during an injection at 840ms. nl_04 steady near 6.6e19. Next shot will include a NINJA puff. LH_B and LH_D will fire at 1200ms. |
| Dec 14 2007 10:25:33:260AM | 1071214005 | Greg Wallace | Clean shot at 100kW per klystron, 500kW net. Next shot will increase 115kW net.
No afterglow or signs of arcing. Stronger signal on ECE (Ch9 at 2.8 by end of shot). nl_04 drops from 6.5->6e19. NINJA will fire on next shot at just after 1.2s. |
| Dec 14 2007 10:35:47:860AM | 1071214006 | Greg Wallace | Clean shot at 115kW per klystron, 600kW net. Next shot at 125kW per klystron.
No afterglow nor arcing. Density a bit higher. nl_04=7.2e19. Much less signal on ECE. ~.9 on Ch9. No real sign of density increase from LH NINJA puff. Will increase pressure to 10psi on next shot. |
| Dec 14 2007 10:52:28:023AM | 1071214007 | Greg Wallace | Shot ran clean at 125kW per klystron, 650kW net. Next shot will increase to 135kW per klystron.
No afterglow nor arcing. NINJA puff at 10psi too much. Will decrease to 5psi for next shot Nonthermals on ECE coming back up to near 2 on Ch9. Density steady near 6.6e19 on nl_04. |
| Dec 14 2007 11:06:11:730AM | 1071214008 | Greg Wallace | Single trip at 700kW (135kW per klystron), retried successfully. Looks like an arc in the upper part of the jungle gym, possibly pant leg splitter or the switch. Forward power drops early on both columns 3 and 4.
No afterglow on LH camera Density still pretty high during LH, nl_04=7-7.25e19. ECE about 1 on Ch9. 5psi for the NINJA looks like it is not causing much density rise locally or globally. This might be a good starting pressure for use with the LH on later in the day. Will move trigger to 1.15s. |
| Dec 14 2007 11:13:29:310AM | 1071214009 | Greg Wallace | Clean shot at 135kW per klystron, 700kW net. Next shot will increase to 145kW per klystron.
Still not much on the ECE, 1.5 on Ch9. nl_04 still a bit high around 7e19. Will try decreasing density before LH turns on for next shot. Maybe a little more density increase visible from NINJA after LH turns off. |
| Dec 14 2007 11:28:32:600AM | 1071214010 | Greg Wallace | Arcing between Magic-T and Pant Leg Split in column 3. Same place as last Friday at slightly higher power level. This was 145kW per klystron, which reached just over 750kW net before tripping. Next shot will decrease to 75kW per klystron, then work up again. Arc duration ~.05ms.
Reflections were noisy at beginning of shot, then quieted down before tripping. Density much better at just under 6e19 on nl_04. Big spike in ECE before the arc. |
| Dec 14 2007 11:40:08:820AM | 1071214011 | Greg Wallace | Shot ran clean at 75kW per klystron (400kW net), next shot will be 100kW per klystron. Nos signs of arcing or afterglow.
ECE signal pretty strong around 1.75 on Ch9. nl_04 srteady around 6e19. |
| Dec 14 2007 11:52:53:343AM | 1071214012 | Greg Wallace | LH ran clean at 100kW per klystron, 500kW net. Next shot will increase to 125kW per klystron.
No arcing nor afterglow. ECE shows 3 on Ch9, density stays around 6e19 on nl_04. |
| Dec 14 2007 12:06:34:957PM | 1071214013 | Greg Wallace | Still clean at 125kW per klystron, 650kW net. Next shot will increase to 135kW per klystron.
No arcing or afterglow. Density slightly higher at 6.6e19 on nl_04. ECE signal at 2.5 on Ch9. |
| Dec 14 2007 12:26:00:777PM | 1071214014 | Greg Wallace | Still clean at 135kW per klystron, 700kW net. Next shot will increase to 145kW per klystron except #2 which will stay at 135kW.
No arcing or afterglow. ECE Ch9 reading ~4, nl_04 around 6.3-6.4e19. |
| Dec 14 2007 12:34:17:077PM | 1071214015 | Greg Wallace | Klystrons 4-8 did not fire, thus tripping he CPS. Will repeat for next shot. |
| Dec 14 2007 01:04:59:730PM | 1071214016 | Greg Wallace | Arc on column 9 between Magic-T and Pant Leg Splitter caused first trip. Second and third trips between Magic-T and Pant Leg Splitter on column 15. Brought power down to 100kW per klystron for next shot. |
| Dec 14 2007 01:06:06:620PM | 1071214017 | Greg Wallace | Clean shot at 100kW per klystron, 500kW net. No arcing nor afterglow. Increasing to 125kW per klystron on next shot.
ECE shows close to 3 on Ch9, nl_04 around 6e19. |
| Dec 14 2007 01:19:27:953PM | 1071214018 | Greg Wallace | Clean shot at 125kW per klystron, 650kW net. No arcing nor afterglow. Next shot will increase to 135kW per klystron.
ECE around 4.4 on Ch9, nl_04 steady at 6e19. |
| Dec 14 2007 01:34:43:037PM | 1071214019 | Greg Wallace | Clean shot at 135kW per klystron, 700kW net. No arcs nor afterglow. Next shot will be same, then switch to gas puffing experiments.
ECE around 3 on Ch9, nl_04 falling slightly from 6.4-6.2e19. |
| Dec 14 2007 01:42:55:307PM | 1071214020 | Greg Wallace | Fizzle. |
| Dec 14 2007 02:05:16:707PM | 1071214021 | Greg Wallace | Cart 2 klystrons did not fire, thus causing the CPS to trip. Will repeat on next shot. |
| Dec 14 2007 02:16:53:210PM | 1071214022 | Greg Wallace | Another fizzle. Switching to LH Gas Puff experiments. Next shot will have 30kW per klystron with the gas puff hitting the plasma at 900ms. |
| Physics Operator Comments | |||
| Dec 14 2007 09:16:49:440AM | 1071214001 | Ron Parker | Good morning. Neither snow(12"), sleet nor rain keeps the C-mod team from starting on time. However, first shot may have been a dud!
It was, may need a little more gas. PG increased from 15 to 20 ms on next shot. |
| Dec 14 2007 09:19:07:580AM | 1071214002 | Ron Parker | The increase in PG worked.Good shot, LH full length at 275 kW net. |
| Dec 14 2007 09:37:42:447AM | 1071214003 | Ron Parker | Good shot, LH stayed on at 350 kW. Non-thermal synchrotron emission on shannel 9, 243 GHz. |
| Dec 14 2007 09:54:59:187AM | 1071214004 | Ron Parker | Shot 4 ran well, LH power up to 450 kW. Injection at .83 s.
Cell access to check high TF thermocouple reading. Non thermal ECE actually decreased even thought power increased. Maybe density limit effect since density is also higher, nl_04 =6.5e19 vs 6.0 |
| Dec 14 2007 10:31:14:310AM | 1071214005 | Ron Parker | Shot 5 ran well ~ 500 kW. Strong ECE (3 V) |
| Dec 14 2007 10:33:37:500AM | 1071214006 | Ron Parker | Shot 6 was OK. 600 kW coupled but density slightly up, ECE down.
We seem to be on the edge with respect to nonthermal ECE. |
| Dec 14 2007 10:52:51:023AM | 1071214007 | Ron Parker | Shot 7 ran well, density still a bit high. LH ~ 650 kW net. |
| Dec 14 2007 10:58:43:697AM | 1071214008 | Ron Parker | Shot was OK, LH tripped once, but recovered. LH power at 700 kW.
Density still rising when LH fires and tends to kill fast electrons. |
| Dec 14 2007 11:24:00:393AM | 1071214009 | Ron Parker | Shot 9 ran well, LH ran full length at 700 kW. |
| Dec 14 2007 11:26:09:410AM | 1071214010 | Ron Parker | Shot 10 ran, density lowered to 5e19 cm-2 on nl_04. LH tripped at 800 kW and couldn't recover. Start again at half LH power and work up. Strong ECE before trip (3 V). |
| Dec 14 2007 12:00:19:237PM | 1071214011 | Ron Parker | Shot 11 ran, LH power ~ 400 kW. |
| Dec 14 2007 12:03:00:237PM | 1071214012 | Ron Parker | Shot 12 was a good one, LH power up to 500 kW. |
| Dec 14 2007 12:05:02:863PM | 1071214013 | Ron Parker | Shot 13 ran, LH power over 600 kW. |
| Dec 14 2007 12:11:07:177PM | 1071214013 | Ron Parker | Shot 13 ran, LH pwr = 600+ kW. |
| Dec 14 2007 12:35:06:310PM | 1071214015 | Ron Parker | OOPs, something wierd, several klystrons did not fire. CPS prevented any LH power from beginning. |
| Dec 14 2007 01:29:36:893PM | 1071214016 | Ron Parker | Shot 16 ran, but many LH trips. |
| Dec 14 2007 01:28:40:677PM | 1071214017 | Ron Parker | Shot 17 was OK, ~500+ kW LH pulse went through. |
| Dec 14 2007 01:30:18:863PM | 1071214018 | Ron Parker | Shot 18 was OK, LH went through, ~ 600 kW. |
| Dec 14 2007 01:33:29:053PM | 1071214019 | Ron Parker | Shot 19 was fine, 700 kW+ LH. 2 ms more pulse gas for next shot. |
| Dec 14 2007 01:57:48:640PM | 1071214020 | Ron Parker | Shot 20 fizzled. Gas had been increased by 3ms -- reason?
Bz ~ .07 mT! It appears that the reference for 5-8 inadvertantly got changed from '10' to Ip. Power room check for supply problem. |
| Dec 14 2007 02:20:51:273PM | 1071214021 | Ron Parker | Shot ran OK, no damage from previous programming error.
LH tripped early and often on filament fault. Not real. |
| Dec 14 2007 02:21:40:960PM | 1071214022 | Ron Parker | Shot 22 fizzled. Probably problem with early gas fueling. Return to shot 10. |
| Dec 14 2007 02:33:32:480PM | 1071214023 | Ron Parker | Shot 23 fizzled, not clear why but increase gas by 2 ms for next shot. |
| Dec 14 2007 02:44:57:207PM | 1071214024 | Ron Parker | Still fizzling. Not clear why. Bz seems higher by 2 mT than at beginning of run,so we'll drop it a bit, 1340 to 1350 A. |
| Dec 14 2007 03:09:40:090PM | 1071214025 | Ron Parker | Shots continue to fizzle. |
| Dec 14 2007 03:10:03:637PM | 1071214026 | Ron Parker | Another one. Nothing works! |
| Dec 14 2007 03:23:54:940PM | 1071214027 | Ron Parker | Another fizzle, we'll ECDC for 30 minutes. |
| Dec 14 2007 04:06:17:207PM | 1071214028 | Ron Parker | After 30 minutes of ECDC, we tried again with the same result,i.e., fizzle.
But then there was too much D2. |
| Dec 14 2007 04:19:05:913PM | 1071214029 | Ron Parker | Still fizzling, but shot lasted ~ 30 ms. |
| Dec 14 2007 04:31:40:887PM | 1071214030 | Ron Parker | Another fizzle. |
| Dec 14 2007 04:42:17:093PM | 1071214031 | Ron Parker | Same thing. |
| Dec 14 2007 04:58:21:943PM | 1071214032 | Ron Parker | Shot 32 fizzled as well. |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 08:59:02:500AM | Plasma | Ok | |
| 2 | 09:11:25:717AM | Plasma | Ok | |
| 3 | 09:27:52:333AM | Plasma | Ok | |
| 4 | 09:41:49:510AM | Plasma | Ok | |
| 5 | 10:13:57:147AM | Plasma | Ok | |
| 6 | 10:26:32:810AM | Plasma | Ok | |
| 7 | 10:39:12:690AM | Plasma | Ok | |
| 8 | 10:52:21:257AM | Plasma | Ok | |
| 9 | 11:05:18:823AM | Plasma | Ok | |
| 10 | 11:17:50:860AM | Plasma | Ok | |
| 11 | 11:34:06:740AM | Plasma | Ok | |
| 12 | 11:46:28:903AM | Plasma | Ok | |
| 13 | 11:58:50:767AM | Plasma | Ok | |
| 14 | 12:12:01:960PM | Plasma | Ok | |
| 15 | 12:29:12:670PM | Plasma | Ok | |
| 16 | 12:42:30:610PM | Plasma | Ok | |
| 17 | 12:59:11:743PM | Plasma | Ok | |
| 18 | 01:11:37:247PM | Plasma | Ok | |
| 19 | 01:25:40:283PM | Plasma | Ok | |
| 20 | 01:38:11:990PM | Plasma | Bad | control system error |
| 21 | 02:00:10:030PM | Plasma | Ok | |
| 22 | 02:12:35:053PM | Plasma | Ok | |
| 23 | 02:25:35:277PM | Plasma | Ok | |
| 24 | 02:38:17:593PM | Plasma | Ok | |
| 25 | 02:51:39:910PM | Plasma | Ok | |
| 26 | 03:08:01:997PM | Plasma | Ok | |
| 27 | 03:20:43:000PM | Plasma | Ok | |
| 28 | 04:02:04:407PM | Plasma | Ok | |
| 29 | 04:15:05:507PM | Plasma | Ok | |
| 30 | 04:27:51:230PM | Plasma | Ok | |
| 31 | 04:40:19:517PM | Plasma | Ok | |
| 32 | 04:57:03:617PM | Plasma | Ok | |
| System Availability | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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