| Miniproposals | ||||||||||
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| Operators | |
| Session leader(s): | Ken Liao |
| Physics operator(s): | Steve Wolfe |
| Engineering operator(s): | Bill Parkin,Bill Cochran |
| Engineering Operator Run Comment |
| MP 694 - Transport of helium impurity in L-mode, H-mode, I-mode |
| Session Leader Plans |
| Entered: Aug 21 2012 03:36:27:140PM |
| Author: Ken Liao |
| Session leader plan for 1120822
MP 694 - Transport of helium impurity in L-mode, H-mode, I-mode Required systems: DNB, Thompson Scattering, ICRF Shot plan: Begin with 2 boronization recovery shots, based off reference shot 1070730018 (H-mode, LSN). Begin with 30ms He4 puff from PG5 each shot at 1.0s. Adjust neon seeding as necessary. Attempt EDA H-mode shots based on 1070730018 (H-mode, LSN), but use a constant 2.8MW ICRF power from 0.7s - 1.5s. After getting EDA H-mode, Repeat configuration 4 times with different beam start times. If we are having too much trouble getting H-mode, then move on to I-mode. Don't spend more than 8 shots here. Generate 4 I-mode shots attempting to replicate 1110215016, except try to have constant input power of 3.0MW during flat top, using 4 different beam start times. Turn off neon Generate 4 ohmic shots using the same equilibrium, nl04 ~ 0.6e20, using 4 different beam start times. Switch to a density scan, starting at nl04 = 0.4. Repeat shot, increasing nl04 by ~0.1 each shot, until nl04 ~ 1.2. If we have time, switch main bottle to Helium-4, run Ohmic plasma, nl04 ~0.6, for several shots until Helium density rises to ne/2. Beam timing: Begin with 60/20 timing, starting at 0.500 seconds, 14 beam pulses Beam start time will be toggled between shots between 0.500, 0.520, 0.540, 0.560, at SL's direction. |
| Physics Operators Plans |
| Entered: Aug 21 2012 06:34:18:787PM |
| Author: Steve Wolfe |
| PhysOp Plan and Engineering Setup for Wed. Aug 22, 2012
MP#694 Transport of helium impurity in L-mode, H-mode, and I-mode SL: Liao PO: wolfe ----------------- Engineering Setup ----------------- REVERSE FIELD RUN Overnight boronization requested, standard prescription 2 hours of He ECDC following boronization There is a possibility that this run may be delayed because there is a DNB problem with transferring LHe. **** Cryopump requested, starting from first shot **** Run begins at 09:00 and ends at 17:00 Power systems as on: 1120821016 (note early EF1 crowbar) Acoil: -Dtop +Dbot +Jtop -Jbot (standard reverse field) Hybrid Enabled Gas setup: ---------- Fill B-Top with 6 psi D2 Hybrid enabled (PG4) fill B-side lower with 3 psi Ne Hybrid DISABLED (PG1) leave B-side upper as is Hybrid DISABLED (PG2) fill B-main with 40 psi D2 Hybrid enabled (PG3) fill H-bot with 10psi He Hybrid DISABLED (PG5) fill NINJA with 10 psi D2 DISABLED Enable gate-valves and shutters: ECE, VUV, HiREX Sr, Xeus/LoWEUS Leave z-bolo shutter as is (should be open) Torvac gatevalve toggle (yes/no): no Boronization(yes/no): YES Overnight ECDC (yes/no): Following boronization ICRF(yes/no): YES LH(yes/no): no Cryopump (yes/no): YES DNB (yes/no): YES Vessel temperature: 35/35/35 ------------------------------ ECDC Parameters (if requested) ------------------------------ gas and pressure: He at 5e-5 Torr sweep: 44/45/103 cm scan: 20/120 s Physop plan ------------ The following can be modified to conform to the SL_PLAN when it gets finalized. We will attempt to access three (maybe four) confinement modes and document profiles of injected helium. We will start by trying to access EDA H-modes with unfavorable drift, at low current and low density so the DNB can penetrate. A reference shot is 1070730018. A similar target in many respects is 1120821016, but without the LH and with 2.5 to 3MW of ICRF. Start with nl04=7e19 and see what we get. Need to keep a reasonably large outer gap to avoid overheating the outer limiters, so reduce RCUR to .657 (same as 1070730018) from .660. May need to provide some neon seeding to keep the inner divertor cool. Start with boronization recovery shots for ICRF. Establish He puff level for satisfactory signal in L-mode plasmas; start with 30msec puff, starting about t=1.0sec, during RF pulse. Get to EDA H-mode conditions as quickly as possible. We will want up to four EDA shots with consistent conditions, but we do not want to struggle with this all day. After 8 tries, move on to the I-mode case. Load an I-mode target from 1110215016, which is essentially a clone of 1120820024, except for the TF current, which I'll need to set back to 159700 for 5.8T. This is a 1MA, 7e19 case with RF from 2.2 to 3.2MW. In the older shot the density program is run negative after 1.0sec, and the Ip does not flattop until about 0.6sec. The Neon seeding from B-side lower was from .32 to .45sec, at 1.9psi. Need to set up the He puff on PG5. Need to remember to have engineering setup changed to 1120820024 and increase TF_CURRENT limit from 165 to 170kA, if it isn't already. Note added after saving initial shot: Matt is recommending that a shot from Tuesday, e.g. 1120821022, which has improved strike point location be used for the I-mode target. The ZCUR for that shot is pushed back up to zero, and there are complicated waveforms on RXL and ZXL. It is also at 1.1MA, and has the early divert and early EF1 crowbar setting, and some EF1 voltage changes, which I don't think are necessarily a good idea. I'll look this over in the morning. Run ohmic case at nl04=0.6e20, using same equilibrium as I-mode. Can turn off neon seeding from here on in. Next we will do an ohmic density scan, nl04= 0.4 to 1.2e20. This is allocated 9 shots. Finally, if there is time, go to He fueled ohmic discharge at 0.6e20. Easiest way would be to run the H-bottom plenum up to 40psi and change the NL04 controller from PG3 to PG5. Probably should turn off the pg3 puff in seg1, if we aren't having runaway issues. Alternatively, pump and purge B-main and replace with 40psi He. |
| Session Leader Summaries |
| Entered: Aug 22 2012 06:27:13:877PM |
| Author: Ken Liao |
| Unfortunately, we weren't able to obtain EDA H-modes or steady I-modes, so not all of the goals of the run were met. We had two disruptions on Ohmic shots, but we were able to get decent data in the ohmic L-mode case. The beam was operating at lower beam voltage and current than in 2011, which resulted in reduced beam enhancement, but it should be sufficient for density profiles in the case of ohmic shots. We finished the run with an abbreviated density scan in ohmic plasmas.
We started off late due to having to replace the liquid helium dewar for the DNB cryopumps, but we made up the time by running to 6pm. The beginning of the run had a lot of difficulty due to a lengthy boronization recovery time for the ICRF antennas. We got some H-modes, but the ICRF faults prevented them from lasting very long, and we probably didn't get EDA H-modes. There was also a large amount of ICRF outgassing which prevented us from keeping a low or steady density. We obtained some short I-modes, which ended presumably because the density would rise above the I-mode accessibility region for a given power. The ICRF outgassing showed up before last night's boronization, but the boronization might have made it worse. We should be able to get radial helium transport from the time dependent density profiles for the ohmic case. |
| Physics Operator Summaries |
| Entered: Aug 22 2012 06:31:46:060PM |
| Author: Steve Wolfe |
PO Summary for Wednesday, Aug 22, 2012
MP#694 Transport of He impurity...
SL: Liao
PO: wolfe
EO: Parkin, Cochran
The machine ran well today, but only a fraction of the run
plan was accomplished. The main problem was that the ICRF
was causing unusually high levels of gas evolution, preventing
density control during the planned H-mode and I-mode phases of
the experiment. Finally, we went to the ohmic L-mode part of
the plan, but were slowed by a cooling-induced leak. We managed
to get through most of the planned density scan, though with
fewer repetitions than wanted.
The run started late because the DNB, which was critical for the
experiment, had run out of LHe and we did not start spinning up the
alternator until it was clear that a new dewar would be delivered.
The run went from 10:17 until 18:00.
Both the 600kA and 1.0MA plasma setups ran well, with only small
changes to the shape programming. However, the boronization recovery
was never really completed, in the sense that a lot of neutral
pressure rise occurred every time the ICRF turned on. Eventually
the RF got past the faulting stage, but the density continued to
ramp up above 1e20 during the RF. This prevented us from sustaining
either EDA H-modes or I-modes, and also reduced DNB penetration to
unusable levels.
The I-mode phase used essentially the same shape adjustments that
Ian and Matt developed on Tuesday, with the ZCUR raised to the
midplane and ZXL up far enough to get the inner strike off the lower
tile, and also swept the outer strike up the vertical plate to spread
the heat load. We did succeed in getting I-modes, not great ones, that
lasted from .55 to 1 sec, until the density rose too much. It's possible
that the decreasing lower triangularity associated with the strike point
sweep compromised the I-mode, but most likely the evolving density
was the problem. There was a very small power window at the start
of RF between the I-mode threshold, around 4MW, and the H-mode threshold
aroud 4.5MW. However ramping the power up to 5MW as the density evolved
(shot#19) had no H-mode, just an I->L transition around 1sec.
The cryopump was used for the first 20 shots, without causing any
burps during shots. However, toward the end it did start having to
be regenned more than once before it would cool correctly, so we
turned it off after the first ohmic shot. It wasn't clear that it
was having any effect on the RF heated shots.
We had what were probably locked mode early disruptions on the 2nd and
3rd ohmic attemps (21-22), which were programmed for 5.5e19 with
no higher density point earlier. Shot#20 had been programmed identically,
and had no problem. After re-programming nl04 to have an early density
bump to 7e19 before the flattop, we had no more disruptions.
Starting on shot#25 we started getting leaks associated with the TF
cooling, as the vessel got down to 20C and the mass 28, 14, and 40
came up. This slowed the shot rate to ~20minutes for the rest of the
run.
Scorecard:
Tests/No power 0
Duds 0
Fizzles 0
Plasmas 30 (including 2 early disruptions)
========== ==
Shots 30
|
| Session Leader Comments | |||
| Aug 22 2012 08:30:34:287AM | Ken Liao | We are looking at a ~1 hour delay for the start of the run in order to refill the DNB cryopumps with liquid He. | |
| Aug 22 2012 09:44:12:187AM | Ken Liao | Helium has been installed in the DNB. | |
| Aug 22 2012 10:29:17:007AM | 1120822001 | Ken Liao | Boronization recovery shot. RF is faulting and needs to clean up.
Plenty of helium signal at 1 second. Beam did not fire for some reason. |
| Aug 22 2012 10:44:37:860AM | 1120822002 | Ken Liao | Boronization recovery shot.
Plenty of helium signal at 1 second. DNB fired successfully, at about 45kV, 5A. Helium signal enhancement is around 5%. Several channels are slightly saturated. Next shot, ICRF will ramp up to try to recover faster. Move helium puff to 0.9, and reduce length to 25ms. |
| Aug 22 2012 11:01:22:680AM | 1120822003 | Ken Liao | Boronization recovery shot.
J-port still faulting a lot. Still saturating helium channels. Next shot, reduce helium puff to 15ms. |
| Aug 23 2012 09:58:43:240AM | 1120822004 | Ken Liao | 15ms is not enough helium. Very little rise is seen.
J-port still faulting a lot. E port also faulting. Beam enhancement ~5% Next shot, increase helium puff to 20ms. |
| Aug 22 2012 11:27:39:200AM | 1120822005 | Ken Liao | Helium puff seems about right.
J-port still faulting a lot. E port also faulting. Next shot, move ICRF start time to 0.5 to give more time for ICRF to condition. |
| Aug 22 2012 11:43:39:403AM | 1120822006 | Ken Liao | ICRF somewhat cleaner. J port cleans up after 1 second. Beam seems somewhat ok. Helium levels are good.
Next shot we will put ICRF at 2.8MW, starting at 0.7 seconds. |
| Aug 22 2012 11:57:18:463AM | 1120822007 | Ken Liao | ICRF is running at 2.8MW, but with many faults. Get H-modes at ~0.8, 1.05, 1.28. H-modes visible in helium spectrum by decrease in ambient helium intensity.
Next shot increase density to try to get EDA H-modes |
| Aug 22 2012 12:20:08:870PM | 1120822009 | Ken Liao | H-modes at 0.8, 1.05, 1.3. nl04 gets to 1.35 during third H-mode. ICRF still flakey, and we can't continue until it cleans up, so keep trying. |
| Aug 22 2012 12:39:36:117PM | 1120822010 | Ken Liao | ICRF does look somewhat better. H-modes around 0.85-1.04, 1.25-1.35, 1.45-1.5
Helium signal seems somewhat less. |
| Aug 22 2012 12:51:49:087PM | 1120822011 | Ken Liao | H-mode at 0.85. Helium signals looking pretty small now. ICRF all antennas fault at 0.9, then J-port faulting almost periodic after 1 second. Beam enhancement very small.
Next shot, increase helium duration to 30ms. |
| Aug 22 2012 01:08:19:780PM | 1120822012 | Ken Liao | Helium signal quite a bit higher now. ICRF is somewhat cleaner. H mode at 0.9, but no others.
Toroidal CXRS channels appear to have a considerably different time trace than poloidal channels between 1.0 and 1.3 seconds. Next shot, try higher ICRF. 3MW. |
| Aug 22 2012 01:39:54:917PM | 1120822013 | Ken Liao | Higher power, but no H-modes, so we will switch over to I-mode configuration. There were some injections. Beam lost a few pulses. ICRF is fairly clean. Beam enhancement is more or less invisible even before entering H-mode, so move on to I-mode.
Injection is visible on CXRS toroidal channel at 0.777m at 1.096s, then immediately afterwards in all channels. Next shot, switch over to I-mode shots similar to 1110215016. Use a constant ICRF power ~2.6MW from 0.5-1.5s. Keep He puff at 0.9s, 30ms duration. |
| Aug 22 2012 02:00:01:980PM | 1120822014 | Ken Liao | First shot in I-mode configuration, don't see any I-modes.
Density is creeping up during ICRF from 1 to 1.3. Beam looks clean, but don't see any clear beam enhancement. Try increasing the ICRF power. |
| Aug 22 2012 02:11:19:557PM | 1120822015 | Ken Liao | Still no I-mode. ICRF Power 3.5MW.
Density is rises the whole time. Beam did not fire this shot. Try increasing the ICRF power some more. Also, adjust DNB timing to 70/30. |
| Aug 22 2012 02:17:57:260PM | 1120822016 | Ken Liao | ICRF Power 4.3MW. H-mode occurs at 0.6. Maybe there was a I-mode immediately before, around 0.55.
Beam enhancement is not clear. Next shot, reduce ICRF to 4MW. |
| Aug 22 2012 02:30:07:333PM | 1120822017 | Ken Liao | ICRF Power 4.0MW. Densities are too high.
Beam enhancement is not clear. Next shot, reduce ICRF to 4MW. Also, turn off NINJA. Drop target density to .55 |
| Aug 22 2012 03:06:44:750PM | 1120822018 | Ken Liao | We aren't getting a stable I-mode because density rise taking us out of I mode. |
| Aug 22 2012 03:08:15:140PM | 1120822019 | Ken Liao | ICRF used a ramp profile to see if it would compensate for increasing density.
4-4.5MW Beam had some faults. Next shot, switch to ohmic shots at low density. Try 5.5. |
| Aug 22 2012 03:19:23:063PM | 1120822020 | Ken Liao | Ohmic shot. nl04 Requested 0.55, got ~0.6.
Some decent beam modulation is visible in the CXRS data. ~6% Next shot. Cryopump off, same density. |
| Aug 22 2012 04:01:13:620PM | 1120822021 | Ken Liao | Early disruption.
Next shot. repeat. Move beam start time to 0.52 |
| Aug 22 2012 04:06:48:200PM | 1120822022 | Ken Liao | Early disruption |
| Aug 22 2012 04:06:21:470PM | 1120822023 | Ken Liao | Full length plasma. Density has some ripples from nl04 .53 - .64.
Beam starts at 0.52. Beam enhancement ~7% Next shot: repeat. move beam start time to 0.54 |
| Aug 22 2012 04:13:53:590PM | 1120822024 | Ken Liao | Good shot. Absolute helium intensity in CXRS data appears to be 30% larger than last shot for some reason.
Next shot, repeat, with beam start time moved to 0.56 |
| Aug 22 2012 04:24:00:097PM | 1120822025 | Ken Liao | before shot, torus pressure is increasing. is there a leak? RGA is showing nitrogen.
It is decreasing now. |
| Aug 22 2012 04:30:42:377PM | 1120822025 | Ken Liao | Beam did not fire. Sequencer problem. This happened on shot 15 as well, so something should probably be looked into.
Plasma looks ok. nl04 ~ 0.6 Try it again, same plasma settings. |
| Aug 22 2012 04:54:53:717PM | 1120822026 | Ken Liao | Beam only fired 5 pulses, only hitting before helium puff, so not so use
nl04 ~ 0.6 Begin density scan. Next shot, change nl04 setpoint to .6, also change beam start time to 0.5 |
| Aug 22 2012 05:10:05:043PM | 1120822027 | Ken Liao | nl04 ~ 0.8
Good beam. Beam enhancement around 5-8% Next shot, change nl04 setpoint to .4 |
| Aug 22 2012 05:29:06:790PM | 1120822028 | Ken Liao | nl04 set to 0.4, got ~0.58
Beam has some faults, but useable. Beam enhancement looks pretty good. Next shot, change nl04 setpoint to 1.0 |
| Aug 22 2012 05:51:09:573PM | 1120822029 | Ken Liao | nl04 ~ 1.0
Beam enhancement is very small. It doesn't make sense to go to 1.2 at this point. Go back to 0.8, where we got decent beam enhancement. Next shot, change nl04 setpoint to 0.8. Also change first beam pulse time to 0.52 |
| Aug 22 2012 06:02:53:103PM | 1120822030 | Ken Liao | nl04 ~ 0.8
Beam faulted on a pulse, but otherwise ok. Beam enhancement looks decent. That's the last shot. |
| Physics Operator Comments | |||
| Aug 21 2012 04:41:18:293PM | Steve Wolfe | Begin setup for Ken Liao's He transport experiment tomorrow. Load from 1120821016, 0.6MA LSN. Raise nl04 to 6e19 (may need to go higher for EDA, but start on the ROT). Outer gap was already at 1.5cm, same as on the reference 1070730018, so leave RCUR at 0.66. Set PG1 (Neon seeding, will be 3psi) from .45 to .65sec at 40% Set PG5 (Helium) to 30msec,100V at 1.0sec In Seg3, import from seg2 of 1120820024. Change TF_CURRENT from 150000 to 159733. Copy PG5 puff from seg2 Leave PG1 puff from .35 to .45 (instead of .32) since the pressure is higher. Save as 1120822000 in ~/pcs_scratch | |
| Aug 22 2012 08:41:00:217AM | Steve Wolfe | Resume setting up for MP#694 Run will probably be somewhat delayed to allow for delivery of LHe for DNB. Load from prepared shot ~/pcs_scratch/*pcs_1120822000 Before doing any changes, save_as alcdata-test::/cmod/trees/test/*pcs/ 1120822000, so I can examine it in iScope without having to redefine the paths. First take a look at the comparison of seg2 in 1070730018 and 1120822000. There is a difference in the EF1_volt program at .2sec which is related to the early EF1 crowbar; also something funny in the EF4_volt at the same time, that's probably irrelevant. The PG1 is different, and my iScope doesn't have the PG5 in it. The substantive changes in the P's are RCUR (3mm further outin 000); Clearin moving out earlier; RXL moves out by 2mm after 1sec ZXL is 5mm higher in the 000 nl04 program is positive past 1sec in the 000 Ip does not have a bump up to 650 before dropping back to 600kA The RXL,ZXL changes are probably to avoid the inner corner region which Matt thinks is the source of injections. This may result in higher threshold though. I can move it back toward the slot if I need to. Next compare the seg3 with 1110215016, the iMode shot, and with 1120821022, Matt's preferred target from yesterday. Here the differences, aside from the current and TF, include RCUR is at .66 in the iMode case and in #22, but at .657 in 000 ZCUR is at 0. after .5sec in #22, but -9mm in the others Clearin rampdown moves in slower in #22 RXL is further in for #22, and then moves out after 1sec ZXL is 2cm higher in #22, different early waveforms Nl04 has slightly different early ramp in #22. I'm going to import_segment 2 from 1120821022 and copy the ZCUR, RXL and ZXL traces into seg3. Leave the RCUR for now. Just for fun, switch to seg3 and do a build; then back to seg2 and build that too. Save as 1120822999 in alcdata-test, to keep something around. Almost forgot to adjust the pg4 in seg1. I'm assuming Sue will get the cryopump on, so raise pg4 from 24 to 45msec. Ian left a substantial pg3 pre-puff before +15msec,dropping from 100 to 50v. That may be slowing down the current rise a bit. I haven't checked what he was doing with seg1 voltages. The EF4 is at 1320, which I think may be too positive, but try it. RCUR offset=-3500 Br_0 offset=-.001 which is the way we left it on Monday I think he may have tweaked the rcur waveform in seg1. Resave this as 1120822999. I seem to have brought up pcs in safe mode, so I can't load it from this session. Bring up the PCS live version Load from 1120822999 Load into model Load at 22-Aug-2012 08:36:48.00 Open tree /home/wolfe/pcs_scratch -1 Open tree done Notice that there is a small non-zero offset on the pg4 puff; set it back to zero and reload. Load at 22-Aug-2012 08:40:08.00 Open tree /home/wolfe/pcs_scratch -1 Open tree done | |
| Aug 22 2012 10:27:36:533AM | 1120822001 | Steve Wolfe | Shot#1: Enable He puff from H-bottom for first shot (contrary to what it says in the PO_Plan). Result: plasma full length Got D-port RF, everything else is faulting. Density is high, reaches 0.9e20 with no seg2 puff. Dalpha spike is very low, probably need more pg4 No GPC, GPC2 Te0 is ok. Next: raise pg4 from 45 to 50msec |
| Aug 22 2012 10:40:27:913AM | 1120822002 | Steve Wolfe | Shot#2: raise pg4 from 45 to 50msec Load at 22-Aug-2012 10:27:31.00 Open tree /home/wolfe/pcs_scratch -1 Open tree done Result: plasma full length Bouncy startup. Density is still high before RF with no puff in seg2. RF gets power from D and E J still faulting. Next: EF4 from 1320 to 1300 PG3 puff down in seg1 |
| Aug 22 2012 10:55:35:307AM | 1120822003 | Steve Wolfe | Shot#3: EF4 from 1320 to 1300 PG3 puff down to 40V from -.01 to +.015 in seg1 Move He puff to 0.9 and reduce length to 25msec Load at 22-Aug-2012 10:45:34.00 Open tree /home/wolfe/pcs_scratch -1 Open tree done Result: plasma full length, density before RF is about 7e19 still no feedback puff in seg2; density rises to 1e20 with the RF. J still faulting, E faults after 1.2sec, D is solid. Still a small bounce in startup, Dalpha spike is slow rise, Zmeter spike is early, 4.5msec. Next: repeat, see if RF improves, density comes down some more. |
| Aug 22 2012 11:06:32:113AM | 1120822004 | Steve Wolfe | Shot#4: Reduce He puff to 15msec see if RF improves, density comes down some more. Load at 22-Aug-2012 11:00:12.00 Open tree /home/wolfe/pcs_scratch -1 Open tree done Result: plasma full length Now SL says too little He, RF still struggling Next: He puff to 20msec, add some pg4 |
| Aug 22 2012 11:25:54:527AM | 1120822005 | Steve Wolfe | Shot#5:He puff to 20msec, add some pg4 from 50 to 55msec Load at 22-Aug-2012 11:08:09.00 Open tree /home/wolfe/pcs_scratch -1 Open tree done Amanda adjusts the GPC gratings for better coverage Result: plasma full length RF still struggling and still raising the density almost a factor of 2. No H-mode. Prf bouncing between 2 and 3MW. Still small bounces in startup, ignore it. Next: repeat |
| Aug 22 2012 11:38:45:417AM | 1120822006 | Steve Wolfe | Shot#6: repeat. RF start time moved to .5sec Result: plasma full length, possible short h-mode early in rf pulse J does better after .9sec, but D faults out then, so total is still low. Pre-rf target is finally down to 6e19, still only negligible gas from feedback in seg2. Next: Keep repeating I guess. LBO has a cell access to adjust CaF2 amount. |
| Aug 22 2012 11:50:59:280AM | 1120822007 | Steve Wolfe | Shot#7: Keep repeating I guess. LBO has a cell access to adjust CaF2 amount. RF will start at 0.7sec again. Result: plasma full length, 3 H-modes, all ELM-free RF gets to 3MW, but still faulting, not only at the transitions Bounce in startup is back. Still very little gas puff in seg2, but target is down to 6e19. Next: Raise target nl04 to 7e19; increase again |
| Aug 22 2012 12:05:07:047PM | 1120822008 | Steve Wolfe | Shot#8:Raise target nl04 to 7e19; increase pg4 again from 55 to 60ms Load at 22-Aug-2012 11:53:57.00 Open tree /home/wolfe/pcs_scratch -1 Open tree done Plasma full length, one short h-mode around 0.9sec? Target density came up to 7e19, as programmed, but RF raises it to 1e20 before the possible L-H. Next: Repeat |
| Aug 22 2012 12:19:08:113PM | 1120822009 | Steve Wolfe | Shot#9: Repeat plasma full length, back to 3 h-modes very similar to 7. Early injection took a bite out of the current at .086sec, but it survived; up till then the startup looked good. RF a little better, faults around the transitions; RF still evolving a lot of neutral pressure. Next: It's getting better, so we keep trying |
| Aug 22 2012 12:30:58:117PM | 1120822010 | Steve Wolfe | Shot#10: Repeat; next shot, consider raising ZXL to get out of the corner, since Mo does come up during the H-modes. Result: plasma full length, longer first h-mode, still not great and not steady. Next: raise zxl by .01 |
| Aug 22 2012 12:46:32:923PM | 1120822011 | Steve Wolfe | Shot#11: raise zxl from -.005 to +.005, lower ZXU by .005, leave zcur alone for now. Load at 22-Aug-2012 12:34:33.00 Open tree /home/wolfe/pcs_scratch -1 Open tree done Result: plasma full length, one h-mode but not long, Prad higher RF J is modulated after 1sec, D single faults at .89 near transition E has a couple of faults, then steady at .9 and .7MW Small bounce in startup Next: increase He puff from 20 to 30msec raise zxl another .01 |
| Aug 22 2012 01:01:03:287PM | 1120822012 | Steve Wolfe | Shot#12: Increase h-bot from .02 to .03sec raise zxl from .005 to +.015, Raise zcur from -.009 to 0. Move early rxl point from .001 to -.005 Getting close to what Matt and Ian did yesterday. Load at 22-Aug-2012 12:52:58.00 Open tree /home/wolfe/pcs_scratch -1 Open tree done plasma full length, h-mode lasts a little longer, still out by 1sec Bounce on startup this time; getting bad. Inner strike now completely off the bottom tile, outer is a bit high, could move rxl in a bit more RF still faulting, looks like the loss of rf is killing the h-mode, not the other way around. Next: RXL in by -.005 |
| Aug 22 2012 01:27:08:560PM | 1120822013 | Steve Wolfe | Shot#13: RXL in by -.005 to -.01 RF will try to raise power on D&E Raise pg4 from 60 to 65msec Load at 22-Aug-2012 13:08:45.00 Open tree /home/wolfe/pcs_scratch -1 Open tree done Alternator has tripped down to speed 2, with no alarms or indications of why. This also happened 20min ago, and they just brought it back up. Right now, it's still going down. Result: plasma full length RF stays on nicely until 1.3 sec at 3.2MW, some injections around 0.77 and 1.1sec, no H-mode? Next: move on to I-mode, turn on seg3, off seg2 Request TF to 175kA |
| Aug 22 2012 01:51:36:357PM | 1120822014 | Steve Wolfe | Shot#14 move on to I-mode, turn on seg3, off seg2 Request TF to 175kA Move H-bot puff to .9 sec Enable B-side lower, neon 2.8psi, from .45 to .65sec at 40% Load at 22-Aug-2012 13:39:33.00 Open tree /home/wolfe/pcs_scratch -1 Open tree done Result: plasma full length Got power 2.5MW, few faults no I-mode. Density ramps up with no gas during RF; ratiomatic gets up to .5mTorr Gpt neon, .13T-l from B-side lower, 2pi diode only sees 0.6MW, no injections. Next: try to raise RF power |
| Aug 22 2012 02:04:05:740PM | 1120822015 | Steve Wolfe | Shot#15: try to raise RF power to get I-mode Result: plasma full length, a few more neuts, but no I-mode RF pretty steady at 3.5MW Density still rising through rf pulse. 2pi diode still at .65MW, not a radiation issue. The only thing I can think of is a triangularity issue. The main problem seems to be the uncontrolled density rise. Next: Yijun will raise power again |
| Aug 22 2012 02:16:56:183PM | 1120822016 | Steve Wolfe | Shot#16: Yijun will raise power again Result: plasma full length; the 2pi diode is missing?? 2pi foil is over 1MW RF faulting early and late, mostly from J-port No I-mode, looks like an H-mode early; maybe an I-mode just before? Density is still rising during RF in following L-mode Try dropping RF to 4MW, find the window. |
| Aug 22 2012 02:28:58:690PM | 1120822017 | Steve Wolfe | Shot#17: Try dropping RF to 4MW, find the window. Result: plasma full length RF steady at 4MW, prad increasing slowly Possible I-mode until 0.9sec, then an I->L transition? Density still rising during RF. Next: try reducing target nl04 |
| Aug 22 2012 02:47:34:177PM | 1120822018 | Steve Wolfe | Shot#18: try reducing target nl04from 7e19 to 5.5e19 NINJA will turn off (they were puffing at 1.4sec, 2.5T-l or so) Load at 22-Aug-2012 14:30:58.00 Open tree /home/wolfe/pcs_scratch -1 Open tree done Result: plasma full length, no H-mode, couple of injections 2pi diode MIA again, foil shows a couple of smallish injections I-mode may have lasted longer this time, but rf-induced density rise still present. Next: Try ramping the RF to keep up with the density rise Running out of patience, may try the ohmic and punt the I-mode too. |
| Aug 22 2012 03:00:55:730PM | 1120822019 | Steve Wolfe | Shot#19: Try ramping the RF to keep up with the density rise Running out of patience, may try the ohmic and punt the I-mode too. Cryopump needs a second try, didn't get fully cold. Frank will need a cell access after this shot. Meanwhile, Bill Rowan and Ken have some concern about the beam plasma full length, one injection early in rf, 1 at 1.2sec, otherwise steady, neutron rate flat and not very high, still lose the I-mode at about 1sec Next: move on to Ohmic L-mode case Disable B-side lower (no more neon) |
| Aug 22 2012 03:18:18:863PM | 1120822020 | Steve Wolfe | Shot#20: move on to Ohmic L-mode case Turn off RF. Disable B-side lower (no more neon) No PCS changes, keep the same equilibrium. Cryo not ready again. After this shot, turn off the cryopump and do the ohmic portion without it, since there's no neon and no H-modes Result: plasma full length. Density at 6e19 Next: change pg4 for non-cryopump start, change TF start time from -1. to -1.1 sec (per Bergerson request) |
| Aug 22 2012 03:33:27:393PM | 1120822021 | Steve Wolfe | Shot#21: chamge pg4 for non-cryopump start, from 65msec to 22msec change TF start time from -1. to -1.1 sec (per Bergerson request), in pcs and engineering start time Load at 22-Aug-2012 15:24:57.00 Open tree /home/wolfe/pcs_scratch -1 Open tree done Base pressure at 3.0e-6 before INIT, hopefully the cryo isn't going to leave a lot of crap around now that it's off. Result: plasma disrupted at .31sec, had an early bounce, maybe some runaways. Next: increase pg4 from 22 to 24msec |
| Aug 22 2012 03:43:57:103PM | 1120822022 | Steve Wolfe | Shot#22: increase pg4 from 22 to 24msec, it was only at 800kA when it disrupted, assume it will still need a little more gas, even after the disruption. IGT=2.8e-6 at INIT Result: same disruption startup was ok Maybe a locked mode, try increasing the density before .5sec |
| Aug 22 2012 04:00:27:320PM | 1120822023 | Steve Wolfe | Shot#23: Raise target nl04 to 7e19 at .3sec, down to 6e19 at .5sec and flat to EOF Put back some pg3 in seg1, 25 to 20V at .1sec Load at 22-Aug-2012 15:52:14.00 Open tree /home/wolfe/pcs_scratch -1 Open tree done Result: plasma full length nl04=6e19, with some wobbles Startup good, small early injection .13sec, some early runaways, not bad. It touches at crossover, not sure how that's changed. Next: Try to repeat |
| Aug 22 2012 04:13:49:533PM | 1120822024 | Steve Wolfe | Shot#24:Try to repeat, no PCS changes Result: plasma full length density looks good. Early runaways are a little bigger, not sure where they come from, there's no sign of a bounce. Ken is seeing a change in the He signal, there was no change in the puff from H-bot Next: repeat that again |
| Aug 22 2012 04:27:20:767PM | 1120822025 | Steve Wolfe | Shot#25:Try to repeat, no PCS changes Nitrogen leak after Ron shut down the cryopump brought the vessel pressure up to 6.5e-6 briefly, back down below 3e-6 at INIT, 2.3e-6 in CHECK Result: plasma full length No beam this shot Next: repeat it again |
| Aug 22 2012 04:50:10:130PM | 1120822026 | Steve Wolfe | Shot#26: repeat it again Getting another nitrogen leak between shots, up to 5.2e-6 then back down, I hope. Slowing down the TF cooling, since that may be what's causing it. N leak coming back up, above 8e-6; pump is off, but vessel went back down to 20C. Vessel up to 24C, IGT down to 2.3e-6; 1.9e-6 in CHECK Result: plasma full length, had injections at .3 and .5sec not sure where they came from. Next: Raise nl04 to 8e19 |
| Aug 22 2012 05:10:03:057PM | 1120822027 | Steve Wolfe | Shot#27: Raise nl04 from 6 to 8e19 Raise pg4 from 24 to 25ms Something went berserk in my PCS session. Acted like a key stuck down problem. Loaded five or six times before I made the pg4 change Load at 22-Aug-2012 16:57:43.00 Open tree /home/wolfe/pcs_scratch -1 Open tree done And we've got another leak and the vessel is down to 20C again. Result: plasma full length, small injection at .5sec, got 8e19, as programmed. startup still good. Next: move f.d. off gate to 1.8sec, stop running more TF than we need. Drop nl04 down to 4e-5 after 0.5sec |
| Aug 22 2012 05:29:33:240PM | 1120822028 | Steve Wolfe | Shot#28: move f.d. off gate to 1.8sec, stop running more TF than we need. Drop nl04 down to 4e-5 after 0.5sec Load at 22-Aug-2012 17:11:35.00 Open tree /home/wolfe/pcs_scratch -1 Open tree done Had to wait for another cooling-related link, Started INIT at 1.9e-6, doing the cooling one quadrant at a time Result: plasma full length, density only down to 5 or 6e19 Next: Raise nl04 to 1.0e20 |
| Aug 22 2012 05:47:32:903PM | 1120822029 | Steve Wolfe | Shot#29:Raise nl04 to 1.0e20 Load at 22-Aug-2012 17:30:04.00 Open tree /home/wolfe/pcs_scratch -1 Open tree done Still fighting the LN2 leak. It is clearly correlated with the TF quadrant cooling coming on. Have to live with it for the rest of the day, only a couple shots left anyway. Waiting for IGT to come back down to 3.0e-6 and now we have I2t invalid; had to reset relays and wait another few minutes. Result: plasma full length, nl04 to 1e20, nice and flat Next (and last): Back to 8e19 |
| Aug 22 2012 06:02:05:693PM | 1120822030 | Steve Wolfe | Shot#30: Back to 8e19 Load at 22-Aug-2012 17:49:19.00 Open tree /home/wolfe/pcs_scratch -1 Open tree done Result: plasma full length nl04=8e19, got beam, looks ok. End of run |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 10:17:34:813AM | Plasma | Ok | |
| 2 | 10:34:08:683AM | Plasma | Ok | |
| 3 | 10:48:57:673AM | Plasma | Ok | |
| 4 | 11:02:20:393AM | Plasma | Ok | |
| 5 | 11:16:04:833AM | Plasma | Ok | |
| 6 | 11:29:33:013AM | Plasma | Ok | |
| 7 | 11:43:16:467AM | Plasma | Ok | |
| 8 | 11:57:00:577AM | Plasma | Ok | |
| 9 | 12:10:33:120PM | Plasma | Ok | |
| 10 | 12:25:00:660PM | Plasma | Ok | |
| 11 | 12:39:27:270PM | Plasma | Ok | |
| 12 | 12:53:50:127PM | Plasma | Ok | |
| 13 | 01:19:28:303PM | Plasma | Ok | |
| 14 | 01:40:19:573PM | Plasma | Ok | |
| 15 | 01:53:01:780PM | Plasma | Ok | |
| 16 | 02:08:33:767PM | Plasma | Ok | |
| 17 | 02:22:02:653PM | Plasma | Ok | |
| 18 | 02:35:31:407PM | Plasma | Ok | |
| 19 | 02:55:41:590PM | Plasma | Ok | |
| 20 | 03:14:17:580PM | Plasma | Ok | |
| 21 | 03:27:43:613PM | Plasma | Ok | |
| 22 | 03:40:14:313PM | Plasma | Ok | |
| 23 | 03:52:40:760PM | Plasma | Ok | |
| 24 | 04:06:12:507PM | Plasma | Ok | |
| 25 | 04:24:57:130PM | Plasma | Ok | |
| 26 | 04:46:09:273PM | Plasma | Ok | |
| 27 | 05:04:18:067PM | Plasma | Ok | |
| 28 | 05:23:27:380PM | Plasma | Ok | |
| 29 | 05:43:01:297PM | Plasma | Ok | |
| 30 | 05:58:38:070PM | Plasma | Ok | |
| System Availability | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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