| Miniproposals | ||||||||||
|
| Operators | |
| Session leader(s): | Amanda Hubbard |
| Physics operator(s): | Steve Wolfe |
| Engineering operator(s): | Bill Cochran,Andy Pfeiffer,Ed Fitzgerald |
| Engineering Operator Run Comment |
| MP 613: LHCD effiectively in high Te and confinement plasmas |
| Session Leader Plans |
| Entered: Aug 12 2010 01:49:09:880PM |
| Author: Amanda Hubbard |
| MP 613: LHCD effiectively in high Te and confinement plasmas
Session leader: Amanda Hubbard Physics operators: Steve Wolfe, David Pace Cryopump, DNB required. Neon should be available for seeding, and D2 in NINJA; both should await SL approval to puff. The general aim of the run is to assess whether LHCD effectiveness at high density is increased at higher temperature - which will be obtained using ICRH. It will follow up on positive results from Greg Wallace's MP 612 on 1100806, which showed a clear dependence on magnetic configuration (USN vs DN, inner wall limited). Part A: USN, L and I-modes 1. Make USN plasma, LHCD only. Start with I-mode shot 1090915027, but reduce Ip to 1.1 MA. Target nel 7e19 m-2 (should give nebar about 1.2e20). Apply LHCD in flat top, 0.6-1.1 MW. N//=1.9, 600 kW . We expect to need, either before or after the first shot, to adjust upper shape for better LH coupling and/or to avoid strike points in bad places for heat loading (ie avoiding leading edges, probes). Use later phase (1.2-1.5 s) to tune and condition ICRF (E, J, perhaps D to have it available). 2. Adjust LHCD N// for mininum accessible value, and increase power if feasible. Adjust plasma shape and/or launcher position if needed to reduce reflections. 3. 1 MW ICRF, 0.6-1.5 s. Delay LHCD to 0.8 s (or when plasma is steady). Monitor HXR, ECE etc for signs of LH absorption. If ICRF causes ne increase, may need to reduce target density to compensate. Use DNB, with a pulse in IC-only phase and one during LHCD. 4. 2 MW ICRF, E and J Repeat. 5. Try 1 MW ICRF, from D-port. I expect this will result in higher reflections and trip out LHCD, but it hasn't been tried with the new launcher post-boronization, so you never know. 6. Increase ICRF to max available. Try to get I-modes! Continue adding LHCD into steady phase. At this point we will need to pay attention to P/ne, and any signs of excessive vessel/limiter heating. Implement Neon seeding and/or strike point sweeping if need be to avoid melting. Part B (Corresponds to D in Miniproposal, with addition of limited discharges). 1. Set up 1.1 MA DN discharge, LHCD only. A starting point for shape is 1100806021. But, increase Ip to 1.1 MA, and program steady nel 7e19 m-2. (I will not attempt inner wall puffing since it is too hard to get constant ne). ICRF may wish to fire after LHCD. 2. Repeat with 1 MW, 2 MW, more? ICRF before LHCD. (upper limit will be set by the H-mode threshold - we will not study H-modes today). 3. Inner wall limited disharge. Start with 1100806030 which gave strong non-thermal signatures. But again, increase Ip to 1.1 MA, and reduce target density slightly (to 6e19 m-2?). LHCD only. 4. ICRF power scan (1 MW, 2 MW, ?3 MW) into Inner wall target. If impurity generation is excessive, try a small (few mm) inner gap - but monitor HXR since we don't know if this will affect LH absorption. Last 1-2 hours of the run (once Brian is available) we will return to a few selected "good" conditions, and repeat with scanning probe. The aim is to see if the far SOL is modified significantly in ICRF-heated vs LHCD-only, and also between configurations. Also make sure to get GPI measurement of fluctuation levels, if not obtained earlier in the run. |
| Physics Operators Plans |
| Entered: Aug 12 2010 02:31:22:010PM |
| Author: Steve Wolfe |
| -----------------
Engineering Setup ----------------- Overnight ECDC in D2: ------------------------------ ECDC Parameters ------------------------------ gas and pressure: D2 at 2e-4 Torr sweep: 44/45/103 cm scan: 20/120 s ********************************************** Run begins at 09:00 and ends at 17:00 Power systems as on: 110806021 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 Enabled (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 DISABLED fill H-bottom with 2psi Neon, Hybrid DISABLED Enable gate-valves and shutters: ECE, VUV, HiREX Sr, Xeus (B-spectrometer) Leave z-bolo shutter as is (should be open) Torvac gatevalve toggle (yes/no): no Boronization(yes/no): no Overnight ECDC (yes/no): Yes ICRF(yes/no): YES LH(yes/no): YES Cryopump (yes/no): YES (starting first shot) DNB (yes/no): YES, if available Vessel temperature: 50/50/50 ************************************************ Physop Plans: Part A: Load from a recent startup with cryopump (probably 1100806021) with active segment from 1090915027 (USN) with multiple changes: Will need all preds recalculated Reduce Ip to 1.1MA Recuce TF to 150kA (5.4tT) nl04 to 7e19 Will further adjust shape to satisfy LH coupling, probably move plasma up and out; also check strike on inner wall. Follow SL_PLAN for bringing up LH, ICRF. Monitor heating of limiters, and impurities from upper div; Begin seeding (Ne) if it seems to need it. If H-bot seeding ineffective, add Neon to pg1 (B-side lower) as in previous runs. Try strike point sweep if seeding inadequate to prevent heating of upper plate. Part B: 1. change to DN based on 1100806021 (or maybe 24?) again set Ip to 1.1MA, nl04 to 7e19. Follow sl plan for raising ICRF up to L-H threshold. 2. When done with DN, go to Inner wall limited. Could load 1100806030 or just scan inner gap in by 1 to 2 cm. May try minimal inner gap instead of actual limiter discharge. Part C: Go back and document interesting cases using scanning probe, may change to He NINJA puff for improved fluctuation measurements. |
| Session Leader Summaries |
| Entered: Aug 13 2010 05:45:40:567PM |
| Author: Amanda Hubbard |
| MP 613: LHCD effiectively in high Te and confinement plasmas
Session leader: Amanda Hubbard Physics operators: Steve Wolfe, David Pace Cryopump, DNB required. Neon should be available for seeding, and D2 in NINJA; both should await SL approval to puff. The general aim of the run was to assess whether LHCD effectiveness at high density is increased at higher temperature. It followed up on positive results from Greg Wallace's MP 612 on 1100806, which showed a clear dependence on magnetic configuration (USN vs DN, inner wall limited). Part A of the run plan, in Upper single null configuration, went quite well. Both LHCD and ICRF performed well in this configuration, independently at least. On shot 4, with ICRF tuning late in the pulse, a clear I-mode was produced. Some shape adjustments were needed to bring the strike point off the corner. Shot 7 serves as a good reference shot with ohmic target, 1.1 MA, 550 kW LH. Higher LH power was available but we found on shots 8 and 9 that it caused W injections (not local to the launcher) and disruptions. On subsequent shots J-port ICRF was increased. Good shots are shot 10: 1 MW shot 13: 2 MW shots 14, 15 2.5 MW, J only. LH and ICRF cleanest on shot 15 On shot 19, ICRF tripped early in the LH. Density was lower, and there was a NINJA puff late, giving a good scan. We attempted to further increase the power by combining J and E port, but in this configuration, this led to high reflections and many trips (shots 11, 18) Hence restricted to J-only, which at 2.5 MW was not sufficient for I-mode. High central Te (to 4.5 keV), but outer Te (r/a~0.9) only about 460 eV. Preliminary analysis of non-thermal emission from ECE shows that the typical non-linear decrease with density is seen. Fall-off is at higher ne than in LSN at 800 kW on 1100806. Comparing different power levels, there seems to be a modest trend towards higher radiation temperature with higher Prad/Te (eg ~ 1.5 vs 1.2 keV at nebar 1.2e20). But, it is certainly not dramatic. HRX camera data were obtained on all shots, and await analysis for a more accurate estimate of the effect. From shot 21 on, we attempted part B: Double Null and Inner Wall limited discharges. This proved much more problematic, mainly just making stable discharges - see physop summary for details. (fizzles, early disruptions....) In particular, DN discharges were vertically unstable. They also seemed to have small ohmic H-modes which could complicate the interpretation. We did get data with LH only at 1.1 MA in limited discharges, which will be useful for comparison with 800 kA shots on 1100806. The same trends were seen, with significantly higher non-thermals at high ne than in USN, and moderately higher non-thermals at the higher Ip. Good shots were: 25: nebar 1.37-1.5 28: nebar 1.3-1.4 (Trad up to 2.7 keV). An attempt to combine LH with ICRF (J-port) on the last shot of the day (29) resulted in many trips for both systems. Clearly running both together is possible but is configuration and parameter dependent. This shot had a late NINJA puff; we hope to compare edge fluctuations with the USN case on shot 19. We unfortunately did not have time to make probe scans in either configuration, given all the disruptions this might have been risky. This should be revisited during a LH-only run scheduled next week. It appears the changes with configuration are more important than with Te, so ohmic data will be very useful. It would also be helpful to diagnose the cause of LH-generated W injections at high ne; is the LH power to SOL heating something up? In summary we did obtain useful new information on LHCD at high ne. But, further experiments, and much analysis, are still required. |
| Physics Operator Summaries |
| Entered: Aug 13 2010 06:20:09:030PM |
| Author: Steve Wolfe |
Physics Operator Summary for Friday the 13th 1100813
MP#613
SL Hubbard
PO Wolfe (assisted by Pace)
EO Cochran, Pfeiffer, Fitzgerald
The run plan included 3 equilibria, USN, DN, and limited
as targets for combined ICRF and LH, to test effect of
Te on LH density limit. We managed to complete most of the
plan for the USN case, but failed on the DN and only got
ohmic cases for the limiter case.
Setting up the target for the USN took longer than expected,
with the main issues being positioning of the strike points
away from the corner and off the leading edges at the pumping
slot. There were some startup issues with runaways, but not severe,
and handled with early gas puffing. We did have a number of 1.1MA
disruptions, including at least one locked mode due to the
density dip at the time of diverting, which has been seen before
with the cryopump on. Fiddling around with the NL04 PID gains,
and a little pg3 feedforward, may have helped stabilize the
density trace during flattop, but this still wasn't absolutely flat.
SL made a virtue out of a defect by using the small oscillations
to map out the density effect on the non-thermal emission, which
is very strong and non-linear in this range (~1.3e20 nebar).
Early on (#4), we succeeded in getting an I-mode condition with ~3.5MW
of ICRF, using all three antennas, but the LH was unable to tolerate
simultaneous operation with anything but J, so the actual experiment
was limited to ~2.5MW, which got up to Te0~4keV. Moreover, asking for
more than ~500kW from the LH resulted in disruptions, apparently due
to W injections that originated someplace remote from the launcher; Matt
suggests the source might be the shelf of the lower divertor.
The USN part of the experiment, with ICRF and LH overlapping, was carried
out on Shots#10-16, all of which ran full length. An attempt was made
to reduce the density during this scan, but without much success. Shot#17
disrupted early, around .45sec at the time of the density dip, although
it didn't really look like a locked mode, and the next shot fizzled.
Shot #19 was a repeat of an earlier condition, at nl04~6e19, with
NINJA coming in at 1.2sec; however, the RF had faulting problems, although
the LH ran clean and generated lots of non-thermals, consistent with the
low density. The next 2 tries at repeating the 6e19 condition with ICRF
disrupted early, during the LH; these did appear to have locked modes.
We then moved on to the next section, the DN target.
After setting it up, I realized that the DN target we had prepared,
based on 1100806024, had the outer strikepoint in the middle of the
pumping duct leading edge tiles, and so would not be suitable for
high power. I made some major mods to this setup, but then decided
it was too big a jump in condtions, and reloaded the original program
into seg4 and started from there. However, we never did get a successful
DN target (shots#21-24, of which 22 and 23 were fizzles). The major
problem was vertical instability, which seemed strange in that the
n/ncrit value did not seem excessive. I tried reducing clearin
by 3mm on shot#24, but this did not seem to help at all,
with the disruption happening at almost exactly the same time as
#21. Furthermore, the strikepoint on #24 was still too far
out, and would have needed to have ZXU moved further up, and RXU
further in to be a suitable target. It's possible that the higher
triangularity would have helped the stability. However, rather than
waste more time, we moved on again, to a limiter discharge, which the
SL considered more interesting anyway. In retrospect, it might have
been better to reproduce the upper xpoint location of the USN
discharges #10-16, and then move in the lower xpoint and zcur
to make the new DN case. I suggest this approach if this MP is tried
again, since the upper null power handling is crucial and there isn't
a lot of room to maneuver up there.
Shot#25 was a limiter case based on the evolved DN in #24 by moving
clearin in by 2cm (and RCUR by 1cm). It ran to 1.4sec, and died with
a locked mode when the density dropped after the LH pulse. There was
no ICRF. The density in flattop was too high, around 1.4e20 nebar,
but attempts to lower this resulted in early locked modes unless we
started with higher nl04 (up to 9e19) and came down, which ended up
with the same flattop density as #25. SHot#28 was a near clone of
#25, with LH and ICRF separate, and decent non-thermal emission during
the LH. Shot#28 was an attempt to heat (2MW) during the LH, but both
RF systems faulted out repeatedly during the overlap time, so this
was not successful, although the shot lasted into rampdown.
One problem encountered in the afternoon was that the cryopump
efficiency seemed to decrease, such that the pre-puff was not
pumped down as much by t=0, leading to at least one fizzle. Dropping
pg4 from 63ms down to 50msec seemed to be sufficient to keep the
startups coming after #24, even when the cryo started pumping well
again and the initial pressure got down to .035mTorr. None of these
startups had any problems with runaways or bounces. This may have
been due to a seg1 pg3 increase made earlier in the day.
For some reason, the limiter discharges seem more susceptible to
locked modes than the USN at the same density. I think we've
seen this before. It's possible we could modify the B21_PROJ
feedback to compensate for this, but that would be a development
on it's own. Meanwhile, I was unable to get a 1.1MA limiter
discharge to avoid locking without raising the nl04 to at least
7e19, maybe more in the early phase. This could be a limitation on
operating space if it persists, if we really want to run much in limter
discharges.
The other issue with the low density limiter cases was high radiation,
which isn't too surprising. The culprit seems to be Mo. I turned
off the Argon puff for shot#28; probably didn't help, but it felt
better than doing nothing.
There were no long data system hangs today, and no power system
glitches. There was a short delay before starting for the cryopump
to fix a slipping stepper motor. The ICRF crew had to change fuses
in the J3 screen supply several times, requiring power room access
and some delay in shots. While it didn't hold up the run, there was
one computer hang (many stations in the control room, and problem
loading from PCS) before shot#25; the cause of this is unknown.
Scorecard:
No Power/tests 0
Duds 0
Fizzles 3
rampup disruptions 1
plasmas 25 (12 into rampdown)
============== ==
shots 29
Total plasma duration: 34.05 s
|
| Session Leader Comments | |||
| Aug 13 2010 09:24:47:317AM | 1100813001 | Amanda Hubbard | Plasma 1.1 MA, 5.4 T. Upper null. Disrupted 1.3 s, perhaps due to strike point in corner.
Got nice clear LHCD 350 kW, N//=1.9. Greg says coupling 'fine' despite odd shape. nebar was 1.3e20, a tad high (aiming for 1.2). Next shot raise LH power, try for DNB at 0.6-0.7 and 0.8-0.9 s. |
| Aug 13 2010 09:35:15:420AM | 1100813002 | Amanda Hubbard | Very short plasma. "something fell in" |
| Aug 13 2010 09:56:39:513AM | 1100813003 | Amanda Hubbard | Good plasma, shape. But unfortunately no LH. Did get HXR - baseline shot I guess. |
| Aug 13 2010 10:07:50:853AM | 1100813004 | Amanda Hubbard | Good plasma, nebar 1.2e20. Very little LHCD. But, in ICRF conditioning phase at the end, we got 3.5 MW, and an apparent I-mode; edge Te to 900 eV and central Te to 5 keV. These are just the kind of hot targets we hope to use later in the run!
|
| Aug 13 2010 10:13:34:603AM | 1100813005 | Amanda Hubbard | Disrupts 0.65 secs - probably due to the locked mode at 0.45 secs. |
| Aug 13 2010 10:30:36:683AM | 1100813006 | Amanda Hubbard | Plasma until 0.78 s. LH on at 0.7 s, ramps to 500 kW.
Good non-thermal response (GPC2_te10 to 1.8 keV). But both thermal and non-thermal emission crash starting about 0.76 s - Prad also rising. Appears that x-point crossing inner corner is leading to the disruption, and also is messing up TS signals. |
| Aug 13 2010 11:19:24:920AM | 1100813007 | Amanda Hubbard | Good shot! LHCD at 0.5 secs into steady USN plasma, ohmic, N// 1.9, nebar 1.2, only 1 trip
Repeat with higher LH power. Then we'll swap LH and ICRF times. (higher power didn't work well, caused injections. So this will serve as our ohmic target reference. Unfortunately DNB was not very good, may want to repeat later if there is time). |
| Aug 13 2010 10:59:26:850AM | 1100813008 | Amanda Hubbard | Disrupts 0.76 secs. LH 640 kW, clean, though Matt thinks it is causing an LH injection. Te and Trad plummet from 0.75 secs, as bolo rises. Still nebar 1.18. |
| Aug 13 2010 11:11:18:260AM | 1100813009 | Amanda Hubbard | Very similar, unfortunately.
Disrupts 0.78 secs. LH 640 kW, clean, Te and Trad plummet from 0.76 secs, as bolo rises. Still nebar 1.18. |
| Aug 13 2010 11:54:52:003AM | 1100813010 | Amanda Hubbard | Backing off on LH power (to 500 kW) in the hope of reducing the radiation problem.
And start the main point of the run (Step 3) Program 1 MW ICRF from 0.6 secs, LHCD from 0.8-1.2 DNB pulses 0.68-0.78 s and 0.9-1 secs. Good shot! Amazingly, all of the above worked. nebar varied, 1.3-1.14 during LH, and Trad is clearly very sensitive. Target Te0 is up to keV (from 1.6 ohmic). And Te8 is 450 eV (from 300). Trad vs nebar is exactly like shot 7 (LH only). Next shot: same timing, 2 MW ICRF. |
| Aug 13 2010 11:44:13:130AM | 1100813011 | Amanda Hubbard |
Programmed 2 MW ICRF from 0.6 secs, LHCD 0.5 MW from 0.8-1.2 LH was not happy with the addition of E-port (many trips due to high R). So next shot, try with J only. Note Greg is increasing shielding on x-rays for shot 12, so data will not be directly comparable. |
| Aug 13 2010 12:03:29:830PM | 1100813012 | Amanda Hubbard | Attempted repeat. Shot and ICRF (2 MW J, only a few trips) were good, but LH had many trips. Not just due to R, apparently. |
| Aug 13 2010 12:35:02:107PM | 1100813013 | Amanda Hubbard | Good shot! 2 MW ICRF (J only) and 0.5 MW LHCD.
Steady nebar 1.3e20 ( a little high). Trad (GPC2_10) 1.2 keV. Pretty closely overlays the prior (lower P) shots, perhaps marginally higher at nebar 1.3 Te0 is up to 4 keV, but Te8 (ICRF only) is 440 eV between heat pulses. About the same as at 1 MW ICRF; Is higher Prad offsetting? We need an I-mode... J-port has issues, which RF crew is working on. |
| Aug 13 2010 12:52:06:010PM | 1100813014 | Amanda Hubbard | Good shot. J-port 2.5 MW, LHCD 600 kW, clean.
Trad up to 1.5 keV, nebar 1.2-1.3 e20 m-3. There is maybe a slight increase wrt lower P shots. Te8 470 eV, Te0 to 4.3 keV. Repeat with slightly lower density, to see effect (if any) more clearly. Then we'll have a go at adding E-port. |
| Aug 13 2010 02:12:24:730PM | 1100813015 | Amanda Hubbard | Very good shot. J-port 2.5 MW, only 1 trip LHCD 550 kW, clean.
Trad up to 1.65 keV, nebar 1.2-1.33 e20 m-3; didn't come down much despite change. But enough to see there is only a small increase in Trad at given ne Interestingly, I do see the non-thermals modulated, rising when (large, ~ 200 eV) heat pulse reaches the edge. This suggests a stronger influence of edge Te over core Te on absorption. Next, try to add E-port power. Not clear whether LHCD will like it. |
| Aug 13 2010 01:39:54:940PM | 1100813016 | Amanda Hubbard | 2.5 MW J Plus 0.7 MW E-port. Unfortunately, as we feared, LHCD did not like it - many trips.
got lower target density, 1.3-1.0 e20 (possibly due to less LHCD??) Next shot, we will remove E-port. And add 0.5 MW D-port late in LH pulse, just to see what happens. Hopefully we will at least get clean LH in the J portion, with reduced density. |
| Aug 13 2010 01:55:19:713PM | 1100813017 | Amanda Hubbard | Disrupts 0.45 s. |
| Aug 13 2010 02:00:39:163PM | 1100813018 | Amanda Hubbard | fizzle |
| Aug 13 2010 02:09:47:380PM | 1100813019 | Amanda Hubbard | Punt on the D-port attempt. This should should be J only + LHCD, with a NINJA puff to get fluctuation measurements.
|
| Aug 13 2010 02:40:01:353PM | 1100813019 | Amanda Hubbard | Punt on the D-port attempt. This should should be J only + LHCD, with a NINJA puff to get fluctuation measurements.
J-port tripped at 0.82 s, very early in the LH. Perhaps partly as a result, nebar was considerably lower than it has been (0.86-1.14). And non-thermals MUCH higher (Trad 13.3 keV, dropping as ne rises due to NINJA puff). |
| Aug 13 2010 02:36:51:143PM | 1100813020 | Amanda Hubbard | ICRF tripped early, closely followed by a disruption. This may all be related to density having dropped (which is not well understood)
Rather than spend more shots figuring all this out, I am going to switch to Part B of the run plan Double null plasmas, 1.1 MA, still aiming for nebar 1.1-1.2e20. LH only. |
| Aug 13 2010 03:13:59:890PM | 1100813021 | Amanda Hubbard | DN discharge attempt. Disrupts 0.84 s, early in LHCD pulse. Also there seems to be a very short ohmic H-mode at 0.81 s - nebar 1.2-1.6. Not clear which if any of these are related. Try again... |
| Aug 13 2010 03:16:16:827PM | 1100813022 | Amanda Hubbard | Fizzle. |
| Aug 13 2010 03:36:03:667PM | 1100813023 | Amanda Hubbard | Fizzle. |
| Aug 13 2010 04:01:37:947PM | 1100813024 | Amanda Hubbard | Plasma, but goes unstable (vertical?) and disrupts early in LH again. Did briefly get Trad up to 2 keV, at nebar 1.2 which is respectable.
Also seem to be getting short ohmic H-modes which will complicate life and density control. Maybe Jerry is right about the low L-H threshold in DN?! It is now 4pm, and for whatever reason this shape is not working out. So, go to the final, inner wall shape which ought in principal to be easier. We'll see. |
| Aug 13 2010 05:10:54:923PM | 1100813025 | Amanda Hubbard | Good shot. Plasma though flat top. Inner wall limited, but close to double null.
nebar was 1.46 to 1.42 e20 during the LH pulse - higher than desired but similar to 1100813030. Trad is 1.5 keV, good for this density. Repeat, hopefully with lower density. Then we will add ICRF. |
| Aug 13 2010 04:21:52:207PM | 1100813026 | Amanda Hubbard | Disrupted 0.45 s, before either LH or ICRF. |
| Aug 13 2010 04:32:51:877PM | 1100813027 | Amanda Hubbard | Very similar, unfortunately. These inner wall limited discharges are harder than I realized.
Disrupted 0.45 s, before either LH or ICRF. |
| Aug 13 2010 04:55:43:670PM | 1100813028 | Amanda Hubbard | Good shot. ohmic target, inner wall limited, 550 kW LHCD. Unfortunately the density did not come down much - 1.39 to 1.3. Trad up to 2.7 keV, higher than before.
After LH turns off, density pumps out a lot - something odd is happening here. Causing a locked mode, a disruption, and hassles for RF tuning. Next (final?) shot, ICRF on at 0.6, and a late NINJA puff. |
| Physics Operator Comments | |||
| Aug 12 2010 03:27:31:373PM | Steve Wolfe | Beginning setup for Friday MP#613 Load from 1100806021, DN in seg 2 (needs mods) Import seg2 from 1090915027:seg2 (USN) ack warning on config Recall preds on RCUR, ZCUR(2,3), CLEARIN, RXL, ZXL, RXU, ZXU Verify with build_all Change TF_CURRENT from 156.4kA to 150kA Reduce Argon puff (PG1) from 75 to 50msec Ip from 1.15 to 1.1MA, nl04 from 8 to 7e19 Import seg2 from 1100806021 to seg3 (DN). This isn't as close to DN as 24, 2mm difference in zcur. I'll use 24 instead. ALso. lengthen time of DN by raising zcur flat in flattop. Change Ip from 800kA to 1.1MA nl04 from 4 to 7e19 Flatten Zcur to -.007 for whole flattop, and in rampdown zero ssep waveform so I can look at the predictor error in phys_aout Reduce pg1 to 50msec Look at seg1: Reduce pg4 from 63 to 55msec Rcur offset=2500 (leave) Br_0 offset=.0005 (leave) IC_EF4U = -1280 (leave) save as 1100813000 in pcs_scratch and alcdata-test | |
| Aug 12 2010 03:46:20:977PM | Steve Wolfe | And another thing: IC_EF4 in seg3 (the DN case) was at 0 amps. OK for 800ka but need more at 1.1MA Paste from seg2, ends up ~2kA. May be an effect on D-ness, matching to antenna. Save again as 1100813000 | |
| Aug 13 2010 08:04:33:403AM | Steve Wolfe | Setting up for today's run In PCS load_from 1100813000 (saved yesterday) Raise pg4 puff from 55 to 60msec, since 55 seemed to be a little on the low side yesterday (bouncy startups) I'm tempted to go ahead and move the xpoint out 1cm, but leave it for first shot and see where it ends up since we did need to recalculate predictors from 1090915027. Load at 13-Aug-2010 08:04:03.00 Open tree /home/wolfe/pcs_scratch -1 Open tree done | |
| Aug 13 2010 10:08:12:873AM | 1100813001 | Steve Wolfe | Shot#1: disrupted at 1.3sec Got lh, got a little ICRF injection during icrf. Strike is in the corner as on 1090915027, move it out next shot. Next: RXU out by .015m |
| Aug 13 2010 10:08:25:153AM | 1100813002 | Steve Wolfe | Shot#2: RXU from -.04 to -.025 pg4 from 60 to 55msec early disruption, .09sec something falls in. runaway dump at .1sec Next: repeat and hope all the loose stuff has shaken loose |
| Aug 13 2010 10:08:51:080AM | 1100813003 | Steve Wolfe | Shot#3: repeat and hope all the loose stuff has shaken loose plasma into rampdown, 1.65sec, dens wobbly around 6e19 icrf trying, 2-3MW with faults LH didn't fire, lost a permissive Next: repeat with adjusted nl04 gains |
| Aug 13 2010 10:07:43:013AM | 1100813004 | Steve Wolfe | Shot#4: repeat with adjusted nl04 gains: P from 9 to 6, I from 0 to 1.5 leave D=6. Leaving pg4 at 55msec slow down IC_EF4 ramp in rampdown, Think about changing xpoint program in rampdown, but don't do it yet plasma full length, 3.5MW ICRF, few faults LH 600kW all faults slight hesitation in startup, density a little better. ECE reaches 5.5keV, possible I-mode, possible L-H near rampdown Inner strike still near corner, outer is on last tile before leading edges. K limiter has a cyan point, GH mild, Bolo skisloping up in rampdown, but never over 2MW Next: repeat, with minor nl04 tweak |
| Aug 13 2010 10:13:39:590AM | 1100813005 | Steve Wolfe | Shot#5: repeat, slow early nl program down, reduce nl04 P gain from 6 to 4 plasma to .7sec, early runaways, bouncy startup locked mode at .4sec, didn't like the lower density Next: raise zxu (should have done it last time) raise pg4 push some gas at .3sec |
| Aug 13 2010 10:29:35:243AM | 1100813006 | Steve Wolfe | Shot#6:raise zxu from .005 to .01, trying to move inner strike off corner raise pg4 from 55 to 60msec, hope it doesn't fizz put nl04 rise back, add pg3 at 40V from .3 to .4sec nl04 P from 4 to 6 again The problem is that the density plummets when it diverts Another early disruption, made it to 0.8sec this time LH came on at .7, got to 500kW injections at .78, doesn't look like a lm this time, but density is oscillatory. I don't like the P=6 strike still gets to the corner just before the disruption Move RXU out another cm |
| Aug 13 2010 10:45:06:540AM | 1100813007 | Steve Wolfe | Shot#7: RXU from -.025 to -.015, zxu from .01 to .015 Clearin to -.0025 point from .414 to .3, first move at .15, trying for early divert Leaving pg4 at 60ms, still risking a fizz after the disruption plasma full length, got LH, got ICRF, got rampdown didn't get early runaways or bounce. nl04 flatter around 7e19 target some injections during lh, neuts/hards shows good non-thermal response no real dip in loop voltage. J4 signal not coming through, looks like J is faulting, D&E ok at .5MW each, max rf ~3MW Some dirt in startup, but ok. injection at 1.55sec, as strike goes back to wall in rampdown Next: leave zxu higher in rampdown to keep strike off inner wall/corner |
| Aug 13 2010 11:07:40:217AM | 1100813008 | Steve Wolfe | Shot#8: leave zxu higher in rampdown to keep strike off inner wall/corner No change to startup or flattop Trying to raise LH this time early runaways, disrupts at .8sec, during LH, got to 600kW bouncy startup with a big vertical thrash Next: raise pg4 again |
| Aug 13 2010 11:16:24:393AM | 1100813009 | Steve Wolfe | Shot#9: raise pg4 from 60 to 65ms Matt says last disruption was W and thinks it's related to LH non-local to launcher. He suspects shelf Try lowering ZXL some more, reducing elongation a bit Drop zxl from -.04 to -.05 Result: another disruption around .78sec, during LH startup dirty but no bounce and norunways radiation comes up with LH, lots of ufo's chasing around Did get slightly lower k, shelf deeper into sol, but didn't help. Next: Backing off LH power, bring ICRF in at 0.6sec No dpcs changes |
| Aug 13 2010 11:28:45:913AM | 1100813010 | Steve Wolfe | Shot#10: Backing off LH power, on at .8sec, bring ICRF in at 0.6sec No dpcs changes Result: plasma full length, got lh, got icrf (1MW) no runaways, still lots of CIII in startup, but nice current rise Nice shot. nonthermals seem to peak at 1.05sec, then drop during constant LH, ICRF, maybe a tiny drop in nl04 Next: NLO4 P gain from 6 to 4 after .6sec |
| Aug 13 2010 11:41:15:610AM | 1100813011 | Steve Wolfe | Shot#11: NLO4 P gain from 6 to 4 after .6sec No startup changes SL calling for more ICRF (step 4 of plan) Plasma full length, some early runaways, bounce on startup LH faulting repeatedly, got 2MW ICRF (E&J), J still faulting at higher power late in shot nl04 looks flatter, but maybe not a fair comparison Next: raise pg4 again, 10A on EF4 |
| Aug 13 2010 12:02:29:967PM | 1100813012 | Steve Wolfe | Shot#12: raise pg4 from 65 to 70ms, EF4 from -1280 to -1270 plasma full length, still some early runaways, though no bounce LH had a problem, lots of faulting nl04 a little more oscillatory this time, some ICRF trips Next: no changes |
| Aug 13 2010 12:21:43:680PM | 1100813013 | Steve Wolfe | Shot#13: no PCS changes, LH will try again plasma full length, still some early runaways but lower than 12 no bounce, fast current rise. Good LH, ICRH ok, Te0 up to 3.2keV with 2MW of J power Limiter TC energy display failed on this shot, but Matt says temp rises ok Next: No PCS changes Delaying for ICRF problem |
| Aug 13 2010 12:51:27:043PM | 1100813014 | Steve Wolfe | Shot#14: No PCS changes ICRF request to 2.5MW (J alone) plasma full length, still getting early runaways; fast current rise Injection at .61sec, near IC turn on J faults early, but manages 2.5MW, LH ran clean Limiter tc display is back this shot, some yellow on both upper gh and lower AB. Next: raise pg4 a tad? Drop target density by 1e19 |
| Aug 13 2010 01:06:12:487PM | 1100813015 | Steve Wolfe | Shot#15: Drop nl04 from 7 to 6e19 pg4 from 70 to 75msec plasma full length, still early runaways, got higher pressure but not much increment density at 20msec; next time try the seg1 pg3 LH and IC both ran cleaner. nl04 did not come down much, if at all. Gas is off after .6sec Next: Continue with power from E; increase seg1 pg3 puff IC lost another fuse (or something) on J3 screen. Delay for repair |
| Aug 13 2010 01:33:26:157PM | 1100813016 | Steve Wolfe | Shot#16: increase seg1 pg3 puff, point at .01sec from 25 to 40V Remove pg3 puff at .3 sec in seg2 plasma full length, no runaways, nl04 still not down much, may have increased the early dip (that is what the pg3 was supposed to help). Looks like it puffed more after the dip, when P is still up at 6. could drop it to 4 earlier. Could also dely I until later. LH not happy with E power, probably going to abandon high power Next: Delay Nl04 I gain until .6sec |
| Aug 13 2010 01:50:34:847PM | 1100813017 | Steve Wolfe | Shot#17: Delay Nl04 I gain until .6sec RF changing timing on E,J Disruption at .45sec, looks like an injection no locked mode, but it does happen at the density dip Next: put back the 40V pg3 puff at .3 to .4sec and try again |
| Aug 13 2010 02:01:17:063PM | 1100813018 | Steve Wolfe | Shot#18: put back the 40V pg3 puff at .3 to .4sec and try again fizzle, should have dropped pg4, no current rise at all Next: drop pg4 10% |
| Aug 13 2010 02:23:40:117PM | 1100813019 | Steve Wolfe | Shot#19: pg4 from 75 to 68ms. still have the 40V pg3 puff at .3 to .4sec from #18 Will have NINJA puff on the next shot for gpi fluct & cxrs measurements Abandoning D power try plasma full length, lots of hards to 6e14 during and after LH nl04 wobbles about 6e19, RF faults at .87sec, LH runs pretty clean Dirty startup, but it ran, no bounce no runaways hints of vertical instability after 1.3sec, li(3)~1.2 Next: No changes |
| Aug 13 2010 02:35:04:017PM | 1100813020 | Steve Wolfe | Shot#20: No changes disrupts at .7sec, during rf before lh possible locked mode? I think it locks at the dip then unlocks briefly during rf and locks again, causing a second density dip. Next: move on to DN case |
| Aug 13 2010 03:06:18:910PM | 1100813021 | Steve Wolfe | Shot#21:move on to DN case. turn off seg2, on seg3 Strike points from original shot 1100806024 are too far out, onto leading edge; need to move ZXU up. Move zxu from -.008 to +.005, rxu from .0055 to -.0055 zxl from -.001 to -.01, zcur from -.007 to -.004 Leave startup as is. Don't use this, reload seg4 from seg3 on shot#20 and use that then tune from there. disrupts at .82sec, slow current rise. vertical instability next: decrease clearin, tweak upper xpoint, zcur |
| Aug 13 2010 03:18:25:907PM | 1100813022 | Steve Wolfe | Shot#22: Still working in seg4 clearin from .003 to 0, tweak upper xpoint, zcur zxu from -.008 to 0, zxl from 0 to -.01 pg4 from 68 to 62msec nl04 P from 9 to 6, then 4 at 0.6sec, D from 0 to 6, I=0 fizzle, slightly late bd 6.5ms, no current rise, slow bz rise Next: EF4 from -1270 to -1280 |
| Aug 13 2010 03:33:00:090PM | 1100813023 | Steve Wolfe | Shot#23: EF4 from -1270 to -1280;pgr from 62 to 58ms From previous load: clearin from .003 to 0, tweak upper xpoint, zcur zxu from -.008 to 0, zxl from 0 to -.01 nl04 P from 9 to 6, then 4 at 0.6sec, D from 0 to 6, I=0 another fizzle? Pressure went up, despite dropping the pg4. Cryopump burp? Pressure is at .068mTorr, 10% higher than #22 with a longer puff. Next: pg4 to 55msec, probably get runaways |
| Aug 13 2010 03:51:37:120PM | 1100813024 | Steve Wolfe | Shot#24: pg4 from 58 to 50ms, looks like the cryopump isn't pumping down the prefill From previous load: EF4 from -1270 to -1280 clearin from .003 to 0, tweak upper xpoint, zcur zxu from -.008 to 0, zxl from 0 to -.01 nl04 P from 9 to 6, then 4 at 0.6sec, D from 0 to 6, I=0 cryo burped during init, down to 1.4e-7 at pulse plasma to .8sec, disrupts during LH, still thrashing vertically starting pressure down to .04mTorr, no bounce! small marfe at .38sec crossover Next: try going inner wall limited from this shape |
| Aug 13 2010 03:58:36:020PM | 1100813024 | Steve Wolfe | Shot#25: try going inner wall limited from this shape clearin from 0 to -.02, RCUR from .6585 to .6485 Load fails because some computers are frozen Got as far as about to ask alcdata-models to copy /home/wolfe/pcs_scratch/pcs_model to /cmod/trees/models/pcs/pcs_model |
| Aug 13 2010 03:59:58:267PM | 1100813024 | Steve Wolfe | Shot#25: try going inner wall limited from this shape clearin from 0 to -.02, RCUR from .6585 to .6485 Load fails because some computers are frozen Got as far as about to ask alcdata-models to copy /home/wolfe/pcs_scratch/pcs_model to /cmod/trees/models/pcs/pcs_model Load finally completed. Going to do it again, just in case |
| Aug 13 2010 04:11:32:547PM | 1100813025 | Steve Wolfe | Shot#25: try going inner wall limited from this shape clearin from 0 to -.02, RCUR from .6585 to .6485 Load fails because some computers are frozen Got as far as about to ask alcdata-models to copy /home/wolfe/pcs_scratch/pcs_model to /cmod/trees/models/pcs/pcs_model Load finally completed. Going to do it again, just in case loaded fine, hope it runs plasma to 1.4sec, early marfe, got LH, generated some non-thermals locked mode at 1.35sec, density dropping from 1.2sec when LH goes off. Drop density by .2 if possible |
| Aug 13 2010 04:25:15:777PM | 1100813026 | Steve Wolfe | Shot#26: Remove pg3 puff in seg4 nl04 from 7 to 6e19, extend thru 1.5sec IGT 3.3e-7 at pulse disrupts at .4sec, early prad to >1MW, then injections CIII up to .008 at bd, never burns out. Looks dirty from the start slow current rise, but not too bad; gets to 450kA at .1sec Next: repeat |
| Aug 13 2010 04:35:58:870PM | 1100813027 | Steve Wolfe | Shot#27: repeat attempt at limiter case disrupts at 0.4sec again, almost a copy next: raise nl04 before .4sec, turn off argon puff |
| Aug 13 2010 04:52:02:330PM | 1100813028 | Steve Wolfe | Shot#28: pg1 off, nl04 to 8e19@0.25sec add some pg3 feedforward before 0.5sec plasma to 1.4sec, early marfe, density at nebar 1.4e20/m3 same as before, gas is off after .3sec, lm at 1.3sec the end of shot, after LH goes off, despite 1MW of ICRF next: repeat, but NINJA will fire around 1.3sec, may help with lock |
| Aug 13 2010 05:08:26:510PM | 1100813029 | Steve Wolfe | Shot#29:repeat, but NINJA will fire around 1.3sec, may help with lock and ICRF will put in 2MW plasma to 1.7sec, into rampdown RF faulted during LH, and LH faulted during RF Got some non-thermals, not too useful. Still had early marfe. no lm late, possibly due to NINJA; density did not fall. END OF RUN |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 09:09:59:450AM | Plasma | Ok | |
| 2 | 09:26:00:443AM | Plasma | Ok | |
| 3 | 09:39:08:820AM | Plasma | Ok | |
| 4 | 09:54:14:727AM | Plasma | Ok | |
| 5 | 10:07:37:530AM | Plasma | Ok | |
| 6 | 10:21:17:977AM | Plasma | Ok | |
| 7 | 10:35:25:120AM | Plasma | Ok | |
| 8 | 10:50:25:493AM | Plasma | Ok | |
| 9 | 11:06:28:220AM | Plasma | Ok | |
| 10 | 11:21:09:607AM | Plasma | Ok | |
| 11 | 11:35:19:620AM | Plasma | Ok | |
| 12 | 11:52:46:997AM | Plasma | Ok | |
| 13 | 12:07:14:143PM | Plasma | Ok | |
| 14 | 12:40:15:400PM | Plasma | Ok | |
| 15 | 12:53:15:363PM | Plasma | Ok | |
| 16 | 01:23:37:520PM | Plasma | Ok | |
| 17 | 01:42:30:183PM | Plasma | Ok | |
| 18 | 01:57:44:013PM | Plasma | Ok | |
| 19 | 02:10:40:833PM | Plasma | Ok | |
| 20 | 02:24:14:097PM | Plasma | Ok | |
| 21 | 02:56:19:777PM | Plasma | Ok | |
| 22 | 03:12:24:607PM | Plasma | Ok | |
| 23 | 03:26:17:667PM | Plasma | Ok | |
| 24 | 03:41:52:440PM | Plasma | Ok | |
| 25 | 04:02:56:127PM | Plasma | Ok | |
| 26 | 04:15:53:423PM | Plasma | Ok | |
| 27 | 04:28:47:787PM | Plasma | Ok | |
| 28 | 04:41:55:620PM | Plasma | Ok | |
| 29 | 04:54:44:203PM | Plasma | Ok | |
| System Availability | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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