| Miniproposals | ||||||||||
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| Operators | |
| Session leader(s): | Amanda Hubbard |
| Physics operator(s): | Steve Wolfe |
| Engineering operator(s): | Bill Cochran,Sam Pierson,Gary Dekow |
| Engineering Operator Run Comment |
| MP#382 C-Mod/JET/AUG pedestal identity experiments |
| Session Leader Plans |
| Entered: May 8 2006 03:59:05:247PM |
| Author: Amanda Hubbard |
| Session leader run plan for 1060509
On-site leader: Amanda Hubbard with potential remote participation from Wolfgang Suttrop (IPP Garching) and Geoff Maddison (UKAEA) Physics Operator: Steve Wolfe MP 382/PEP-7: C-Mod/JET/AUG pedestal identity experiments Main Aim: This run will continue the experiment begun on 1060427 (which went well but only got 7 full length discharges). Achieve and document high field, high power H-modes in JET/AUG compatible shape, for purposes of pedestal identity matching. Time permitting, scan beta and nu* over achievable range to map out ELM types and give greater range of pedestal targets. Overnight boronization should be performed before the run; see physop plan for details. Maintain option of between-shot boronization, but start with bottle closed in case cell and power room access is needed. He3 needed for RF, D2 puffing may be needed for ne control. Fluctuations diagnostic window ~0.9-1.25 secs. Step 1: Start from 1060427011, (7.85 T, 1.3 MA, target nel 1.1e20 m-3). Reduce flat top length to 1.3 s as per new engineering limits. RF flat pulse 0.9-1.25 s, level 3-4 MW as determined by RF operator. Adjust power on following shot(s) to determine reliable operating point without impurity injections. 3 shots? Step 2. Scan in pedestal density (via target ne) to scan nu*. Since 8 T H-modes to date have been ELM-free and had nu*ped < 1, start by scanning upwards in ne. (For reference, 5.4 T shots had neped = 2e20 m-3, Teped ~ 400 eV and nu*ped= 2.1). Targets 1.2e20 m-2, 1.3e20 m-3... Given limited RF power and high BT, we anticipate that at some point the LH threshold will not be reached. If and when this occurs, try reducing target nel and puffing D2 during H-mode with NINJA. 6 shots? Time (and engops) permitting, try moderate scan in q95, down to q95=3.1 (Ip approx 1.7 MA). This is close to EDA/ELM-free boundary at lower B, would be of interest to check ELM type in this Bt regime and would give a more directly ITER-relevant high-field pedestal and confinement scaling point -plus contribute to a future C-Mod milestone. 3 shots? |
| Physics Operators Plans |
| Entered: May 8 2006 05:16:30:373PM |
| Author: Steve Wolfe |
Physop plan and engineering setup for Tuesday, May 9 MP#382 C-Mod/JET/AUG pedestal identity experiments SL: Hubbard (with remote help from G. Maddison and W. Suttrop ?) PO: wolfe Overnight boronization on Mon night. ********************************************************* * NOTE: PEI Sweep limited to <80cm * * This is different from previous boronizations in 2006 * ********************************************************* 20% B2D6 / 80% He 6L bottle. vessel temperature at 60/60/60. 60 psi to be deposited. PEI setting to 44/70/80 (Rmin/Rres/Rmax) with no pulser. Gas Pressures: TC3/TC6/TC9/TC6Request = [4 to 7]/150/95/150 Follow boronization with 4 hours ECDC in helium. Run may be delayed for of order one hour so that RF Group can perform Multipactor/RF Glow conditioning on J-port antenna. Engineering setup: ------------------- Power system setup as on 1060427008 Except: TF Invert time set to 1.3sec 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 with 15psi He3. Hybrid enabled (PG2) fill B-main with 40 psi D2 Hybrid enabled (PG3) fill NINJA with 10psi D2 (Disable) Enable the following gate valves and shutters, assuming no vacuum problems: ECE, VUV, Z-bolo shutters FMIT#1,2,3,4 in Run-on by 8:30AM; turn on earlier if requested by RF Plasma Control Setup: --------------------- Start from 1060427011 (NL04=1.1e20) Change TF rampdown from 1.4sec to 1.3sec Adjust density per SL_PLAN, first up then down. Hope the RF is working well enough, and that the injections that kept killing shots last time have gone away. If we get to the part of the SL plan that calls for higher currents, up to 1.7MA, remember to change the Ip gains as called for in the PO_PLAN for 1060427. |
| Entered: May 8 2006 11:30:12:397PM |
| Author: Steve Wukitch |
| RF Glow Discharge Conditioning Engineering setup (likely to happen around 7 am)
PEI setting to 2500 A, no sweep static gas fill 1e-3 (will be conditioning for ~ 1 hour, nearly ran out of gas last time which went for ~40 minutes) RGA open RGA gatevalves and turn on RGAs following the boronization close GV1 open bypass to 300 clicks set file writing rate to once/minute RF power set to -15 dBm initially (increased till mulitpactor strikes) HP output split to power #1 and #2 Kalmus Record and monitor power multipactor strikes |
| Session Leader Summaries |
| Entered: May 10 2006 11:37:07:603AM |
| Author: Amanda Hubbard |
|
On-site leader: Amanda Hubbard with some remote participation from Geoff Maddison (UKAEA) Physics Operator: Steve Wolfe MP 382/PEP-7: C-Mod/JET/AUG pedestal identity experiments This run was a continuation of the 8 T H-mode run on 1060427, with the primary goal of seeing whether a more steady, EDA-like H-mode could be obtained with higher ne and more RF power. Operationally, the run went much better, with 17 full length 8 T plasmas produced, no apparent power supply problems and only one early disruption and one fizzle. See physop summary for details. D (He3) heating also went well; while we did not do systematic studies, the strong central Te response indicated good central absorption. We thus now seem to have a 'recipe' for 8 T heated plasma studies. We did not, however, make a great deal of progress in expanding the parameter space at q_95=4.1, primarily due to limited RF power. Conditioning after the (shorter, less radially extended) boronization proved slow and problematic. The first few shots established that, with target nel programmed to 1.1e20 m-2, the RF threshold power was 3.2 MW; the first short H-mode was obtained at this power on shot 8. As on 1060427, H-modes were basically ELM-free and transient, with density and radiated power steadily increasing, leading to H-L transitions or short ELMy periods. RF trips and impurity injections were also common and contributed to early H-Ls. Probably the best H-mode at this target condition was shot 11, with 3.2 MW most of the time, and H-mode 0.95-1.1 secs. In each case, Tedge at the L-H and H-L transitions was equal (Te8 540 eV, Te9, at r/a~0.96, at 340 eV; this is very consistent with threshold results in 1996!). Given that the available power essentially equalled the threshold power, there was, not surprisingly, little success in raising the target or H-mode density. A similar ELM-free H-mode was obtained on shot 13 with target 1.2e20 m-2. A further increase to 1.3e20 m-2 on shot 14 caused neutral pressure trips on J-port (Shot 14). For shots 15-17 we tried reducing the target density and puffing later, into what should have been the H-mode. However, H-modes did not occur, despite about 3.1 MW, illustrating how close to Pthresh we were. On shot 17, with target reduced to 1.0e20 m-2, did get the H-mode back(wihtout a puff). A puff was tried on shot 19 but the H-mode lasted only ~ 100 ms, and the gas likely had little effect. For the last few shots it was decided to explore higher current H-modes. Shot 20 has 1.7 MA, giving q95=3.19. To my surprise it remained in L-mode despite 3.1 MW RF and > 2 MW Poh. However, RF ran clean. For the last shot, 22, power was raised to 3.8 MW, giving 2-3 H-modes and stored energy up to 184 kJ. D-alpha and Teedge were rather erratic, the H-mode type is hard to classify but it was certainly not steady; there may have been some ELMs. Te95 was ~ 600 eV, ne95 ~ 2e20, nu* ~ 0.6. This condition would be interesting to revisit on a future pedestal scaling run. It is not clear whether the RF coupling was better at the higher current or whether it simply required many shots to fully condition J-port after the boronization. |
| Physics Operator Summaries |
| Entered: May 9 2006 05:56:16:870PM |
| Author: Steve Wolfe |
PO Summary for 1060509
MP#382 JET/C-Mod/AUG Pedestal identity
SL: Hubbard
PO: wolfe
The machine ran considerably better at 7.8T today than the
last time we tried this experiment (1060427), but the ICRF
power was still problematic. We were limited to a maximum
power of ~3.2MW for most of the day. As a result, we were
pinned close to the LH threshold, and were unable to raise
the density above 1.2e20 and still get into H-mode. The problem
was compounded because at the puff necessary to get to 1.3e20
the neutral pressure was too high for J-port to operate even
at the 1MW level. Several attempts to puff gas into an H-mode
established at a lower target density were unsuccessful in
producing anything that looked like an EDA. We got several
cases with nu*_ped in the range of 1-2, but these still looked
ELM-free. Maximum wmhd was about 170kJ.
At the end of the run we raised the current from 1.3MA to 1.7MA
(q95~3.2), and the RF ran clean, with J-port even able to step
up in power to the 2MW level, for a brief period of 4MW. However
this case (shot#20) remained in L-mode, despite over 2MW of ohmic power on
top of the RF. On the last shot of the day we succeeded in getting
an H-mode at 1.7MA with up to 4.4MW of ICRF; Wmhd made it up to
about 185kJ on this shot (which almost died of an early injection).
No idea why J-port now likes high current, but it seemed to help.
Without the injections this could have made it into record territory.
As it is it may be the highest stored energy we've had at 8T. Prad_main
was under 2MW for the whole RF pulse. Probably we haven't completely
killed off the boronization today, so Jim may not need to do between-
shot tomorrow, at least to start.
After the first couple of shots I moved the Ip rampdown to start
at 1.3sec. The TF rampdown was changed from 1.4 to 1.3sec from
the beginning of the day, and we had no recurrence of the type 2
faults that plagued the 1060427 run. The engineers checked fuses
in the TF every 7 or 8 shots, and reported no fuse losses today.
For the 1.7MA shots I used the gain programming specified earlier,
and raised the IC_EF4U current program from 2000 to 2500. The actual
EF4 current was on or close to the current rail (5000A), as expected.
The EF1U current was on the rail after 1.1sec, but I don't think the
shape was badly compromised.
We had a problem with the main pulsed gas valve (B-main, PG3) at
the start of the day. On shot 1 it appeared not to open at all,
despite full-on demand and voltage from the driver. Density stayed
below 5e19 with programming of 1.1e20, and the plenum pressure did
not drop at all. Shots#2-4 were gas puff tests, on which it looked
like the valve was opening late and only when the voltage demand
was on full. After exercising it some and re-programming the PG3
feedforward to turn on hard at the start of seg2, it seemed to work
better the rest of the day. This behavior bears watching; we may need
to change out this piezo before long.
See posting by Gary Dekow under Discharge_clean topic for an account
of the boronization problem last night. It appears we only got a little
over half the requested deposition, based on elapsed time. It was
determined during the day that there was a leak between PV6 and the
final piezo valve. Tommy will work on fixing this tonight.
Injections were much reduced from 1060427, but not altogether gone.
We lost one shot to an early injection and almost lost the last one.
These both seemed to come from the area of the nose seen in the
Wide 2 (F-port) view. There were also numerous injections during the
RF pulse from the J-antenna; Matt identified these as titanium!
Startup was pretty good using the 8T startup prepared last time.
The first couple of shots had runaways, but they went away on their own.
I made a couple of pg4 tweaks after the
early disruption (successful) and a rampdown disruption on the first
1.7MA shot (1ms wasn't enough, 2 more msec after the fizzle ran fine).
Bz started out a little negative and crept up on its own.
NOTE: This startup should probably NOT be used at 5.4T, since
the fields are tweaked up to compensate for the higher TF current.
Scorecard:
----------
Tests 3
Duds 0
Fizzles 1
Plasmas 18 (including one early disruption)
------- --
Shots 22
|
| Session Leader Comments | |||
| May 9 2006 09:47:30:583AM | 1060509001 | Amanda Hubbard |
This shot had much lower density than was programmed (got nel= 3e19 m-2, vs 1.1e20 m-2). Apparently a gas fuelling issue, which is being investigated - next shot will be gas only. As a result we got low RF power (~ 1 MW). The ne rise is apparently fuelling, not an H-mode (which would have been surprising in these conditions). Also as a result of the low ne, GPC 1 and 2 saturated (T ~ 4 keV). |
| May 9 2006 11:34:06:693AM | 1060509002 | Amanda Hubbard | Gas test |
| May 9 2006 11:34:11:820AM | 1060509003 | Amanda Hubbard | Gas test |
| May 9 2006 11:34:17:443AM | 1060509004 | Amanda Hubbard | Gas test |
| May 9 2006 10:40:12:177AM | 1060509005 | Amanda Hubbard | Got the requested target ne. But, only 1 MW steady RF (from D)
L-mode, naturally. Now need to tune RF to this target. |
| May 9 2006 11:01:40:223AM | 1060509006 | Amanda Hubbard |
Similar target. Still L-mode. Got 1.2 MW D+E, plus ~ 1 MW (tripping) from J. Repeat. |
| May 9 2006 11:33:09:833AM | 1060509007 | Amanda Hubbard | Still L-mode. RF increasing shot to shot, max 3 MW now but still tripping a lot.
Keep trying... |
| May 9 2006 11:45:37:600AM | 1060509008 | Amanda Hubbard |
Finally a short H-mode, 0.98-1.02 seconds. Took 3.1 MW RF. Terminated by impurity injections. 120 kJ. Te,95 ~540 eV, ne95 ~1.8e20; both were still rising. |
| May 9 2006 12:23:38:490PM | 1060509009 | Amanda Hubbard | Somewhat longer H-mode. RF to 3.2 MW, but trips in H-mode so never gets very hot.
ne and Prad keep rising, leading to back-transitions or ELMy bursts. No QC mode seen on PCI.. Teped briefly 600 eV, drops to ~ 400. neped gets to 3e20 m-3. nu* is therefore high, ~ 2, by end of H-mode. |
| May 9 2006 12:37:48:863PM | 1060509010 | Amanda Hubbard | Similar. Again an H-mode, with RF (E and J) dropping out at or soon after the transition. Note bolo rises 1.09 s, coincident with the ELMy period just before the H-L transition. ne_95 to 2.7e20, neped 2.4e20, Teped ~ 550 eV.
|
| May 9 2006 01:01:18:083PM | 1060509011 | Amanda Hubbard | Best yet. E is staying on, J tripping in H-mode. Net power therefore 2.4-3.2 MW. H-modes are longer, 3 periods.
ne_95 to 3.2e20, te_95 600-450 eV. nu* 1-2, but doesn't look EDA. |
| May 9 2006 01:25:11:570PM | 1060509012 | Amanda Hubbard | Fairly similar. 1st H-mode lasts 0.96-1.128 s. Still some RF trips, up to 3.2 MW. Teped is consistently eroding on each H-mode for last few shots, with H-L at same temp as L-H (Te_9 ~320 eV at r/a 0.96) - good threshold data at a minimum, and very close to 1996 values.
For next shot, start stepping up in target nel t- 1.2e20 m-2 for shot 13. |
| May 9 2006 01:50:02:787PM | 1060509013 | Amanda Hubbard | Target 1.2e20 m-2. - which it was at L-H 0.988 s.
Delayed but still good H-mode. RF if anything is better - J trips less. Pedestal pretty similar - ne95 ramps to 3.4e20 m-3, Te95 600-480 eV. Prad, nel still rising continuously. Next shot, raise target nel some more. |
| May 9 2006 02:23:10:010PM | 1060509014 | Amanda Hubbard | Raised target nel to 1.3 e20 m-2. But, this raised neutral pressure substantially to beyound the limit of J-port. So, got 2.1 MW L-mode.
Next shot, back to 1.2e20 m-2 target, try puffing into H-mode instead. |
| May 9 2006 02:34:49:713PM | 1060509015 | Amanda Hubbard | Got 3 MW RF, but stayed in L-mode. Perhaps our puff was too early.
Next shot, reduce target nel to 1.1e20 m-2, for earlier H-mode. Keep puff on. |
| May 9 2006 03:07:10:137PM | 1060509016 | Amanda Hubbard | Still got L-mode, despite lower target (1.1e20 m-2, same as shots 8-12) and clean 3.1 MW. Not sure why!
I guess we are just very close to L-H threshold. For next shot, reduce target further - to 1.0e20 m-2, same as 1060427010. And turn off gas puff so we can get a better idea of H-mode timing. |
| May 9 2006 03:32:49:993PM | 1060509017 | Amanda Hubbard | Got the H-mode back. Not our best; starts 0.95 secs, terminated by a trip and/or injection at 1.06 secs. Target nel 1.0e20; got 0.97. Got 3.2 MW RF, with some trips.
ne95 up to 2.7e20 m-3, te95 ~ 530 eV. Prad rising strongly. Next shot: 1 more try with gas puff at ~ 1 sec. |
| May 9 2006 04:17:25:777PM | 1060509018 | Amanda Hubbard | Disrupts in current rise - first time today. Much like 1050427... |
| May 9 2006 04:22:10:323PM | 1060509019 | Amanda Hubbard | Got the plasma and short H-mode back. It ends at 1.04 seconds, probably just due to radiation rise and RF trips. D has a problem.
Not clear that the gas puff has time for much effect in these short H-modes. ne95 only gets to 2.5e20 m-3 (lower than earlier shots), Te95 60-550 eV. Given we only have a few more shots, try going up in current (1.7 MA, q95 ~ 3.1) for next shot. Keep same target ne, do not puff. Expect to get bigger pedestals, maybe we'll have more headroom in Pthresh. |
| May 9 2006 04:38:04:637PM | 1060509020 | Amanda Hubbard | Got 1.7 MA, q95=3.1 MW. Also nice clean 3.17 MW RF, with increase to 4 MW late in pulse. But, to my surprise, no H-mode! Target nel 1.04e20, gets to 1.3 e20 m-2 during RF pulse which may be part of the problem. But 2+ MW of ohmic power should have helped.
There were two dithers at (large) sawtooth heat pulses which suggests we are close. Next shot: Raise power to max and repeat. |
| May 9 2006 04:51:50:150PM | 1060509021 | Amanda Hubbard | Fizzle. Try one more time... |
| May 9 2006 05:17:37:103PM | 1060509022 | Amanda Hubbard |
Got the plasma - 1.7 MA. Got the H-modes, and the RF power 3.9 MW, up to 4.4 late. That's all folks. |
| Physics Operator Comments | |||
| May 9 2006 07:16:37:723AM | Steve Wolfe | Boronization had a problem last night, only got two hours + another 20min, as opposed to the usual four hours, because the pressure in the bottle was dropping twice as fast as usual. Pressures in the machine were normal, and there is a suspiscion of a leak in the system that was allowing additional diborane to go somewhere other than into the torus. However, there were no diborane alarms. I would guess we got a little more than half the standard deposition. Since we were putting it over a smaller sweep area, this may be ok. The diborane system will need to be carefully checked to determine what happened. See Gary's entry for more details. | |
| May 9 2006 07:31:50:787AM | Steve Wolfe | Begin setting up for the run. Load from 1060427011 (1.3MA, 1.1e20, TF=220kA) (in Seg2) Change TF rampdown to start at 1.3 sec (from 1.4) Note Ip gain is staircased: 1.8@0,2.6@.356,4.0@0.8 This seems to be consistent with my notes from 1060426 for high current operation, so we should be set to go up to 1.7 when/if SL calls for it. May want to check on ef2byef4 and ef4 program then. Seg1 is the 8T startup from 1060427011; pg4=23msec, ic_ef4u=-1305,Br0=-.0002, EF1 currents=-5800 No changes for shot#1 Load at 9-May-2006 07:30:38.00 Open tree /home/wolfe/pcs_scratch -1 Open tree done | |
| May 9 2006 09:44:57:007AM | 1060509001 | Steve Wolfe | Shot#1: plasma full length Slight bounce on startup, no runaways though Density looks low, but gas valve seems to be on full. It looks to me like the B-main valve isn't actually opening. Got 4e19 before the RF, very hot. Try a gas puff test |
| May 9 2006 09:59:33:820AM | 1060509002 | Steve Wolfe | Shot#2:gas puff test, fd to 0.5sec, All valves off except B-side main Got gas ok, pressure went to 1e-3 on the gauge Valve seems to be responding slow, based on ratiomatic pressure, no rise until.27sec or so. Demand trace looks correct; I've got the early gain turned down to 2 until .4 sec, but a voltage program at 30V, all seem to be there, valve not responding until demand is near full. Try again, see if it needs exercising. |
| May 9 2006 10:06:35:007AM | 1060509003 | Steve Wolfe | Shot#3:Another gas puff test, fd to 0.5sec, All valves off except B-side main Got gas, a little earlier and a little higher. No response at all until 0.18sec. Try programming full on for the half-second, see if we can get it on full. |
| May 9 2006 10:15:15:113AM | 1060509004 | Steve Wolfe | Shot#4:Another gas puff test, fd to 0.5sec, All valves off except B-side main PG3 program at 100V from .1 to .45, plus feedback. Got 3e-3 on the gauge, pressure rise starts at .14sec this time, no obvious response to seg1 puff. This may be the best we can do. |
| May 9 2006 10:31:46:990AM | 1060509005 | Steve Wolfe | Shot#5: Gas valve seems slightly sick. Reset nl04 gain to 8 from start of seg2, change pg3 feedforward to start at 100V, drop to 30 after .2sec Gas valves and fd back to normal settings, dnb gate valve re-enabled plasma full length looked quiet on the TV Some early runaways, No H-mode. Density looks closer to program value. Still only D-port for RF, J and E both faulting. next: extend pg3 feedforward to .3sec |
| May 9 2006 10:55:09:303AM | 1060509006 | Steve Wolfe | Shot#6: extend pg3 feedforward to .3sec; enable Argon Start Ip rampdown at 1.3sec, since the TF is coming down anyway. I should probably tweak Bz up but leave it for another shot. Plasma full length, less hards, a few more neuts. Got E at 300kW and D at 1MW. J faulting but better than last shot. next: increase later pg3 feedforward from 30->40V |
| May 9 2006 11:18:18:333AM | 1060509007 | Steve Wolfe | Shot#7:increase later pg3 feedforward from 30->40V plasma L-mode. Got some J power that time. close to 90kJ in L-mode, some density rise with RF. Touching 3MW on the peaks. One injection during RF at 1.07sec Next: repeat, more rf? |
| May 9 2006 11:42:25:710AM | 1060509008 | Steve Wolfe | Shot#8: repeat plasma, short h-mode, close to 120kJ some injections during RF, starting around 1.02sec All antennas on for part of the pulse, max power ~3MW next: more power? |
| May 9 2006 12:18:03:037PM | 1060509009 | Steve Wolfe | Shot#9: plasma with h-mode, longer this time, near 150kJ No data, dispatcher crashed? Josh recovers the data Peak power around 3.3MW next: repeat, keep trying |
| May 9 2006 12:32:06:427PM | 1060509010 | Steve Wolfe | Shot#10: repeat, keep trying; increase Ar to 40ms Plasma, short H-mode, 150kJ again, injections during rf next: repeat |
| May 9 2006 12:57:31:757PM | 1060509011 | Steve Wolfe | Shot#11: repeat Plasma h-mode, 165kJ RF staying on a little better, but J doesn't go up in power for the second step without faulting. next: and again |
| May 9 2006 01:18:38:693PM | 1060509012 | Steve Wolfe | Shot#12: Plasma H-mode, injections, 170kJ J more faults early this time. next: raise target density by 0.1 |
| May 9 2006 01:46:59:973PM | 1060509013 | Steve Wolfe |
Shot#13: Nl04 from 1.1 to 1.2e20,
extend pg3 to .7 and raise level from 40 to 50V
plasma H-mode, not as high energy 158kJ
RF a little cleaner before the J-port power step
Had a paranormal event on the data system, somehow
current_shot('cmod') thinks it's shot#10. Data are
there for shot 13 if we type it in.
Had some early injections starting at 0.5sec
Density sagged some just before rf
Next: raise nl04 another 0.1, keep pg3 on until .9sec
|
| May 9 2006 02:10:08:007PM | 1060509014 | Steve Wolfe | Shot#14: Nl04 from 1.2 to 1.3e20, extend pg3 to .9sec, still at 50V plasma no h-mode. J-port faulted out early, E faulting after 1sec nl04 1.25e20, main chamber pressure up to 0.8mTorr, could be over the limit for J? |
| May 9 2006 02:30:55:353PM | 1060509015 | Steve Wolfe | Shot#15: Drop nl04 back to 1.2e20, gain off after 1.0 and turn pg3 on full from 1.0 to 1.3sec (puff into the H-mode) Plasma, no H-mode, got the puff though; it raised nl04 up to 2e20. Got a clean 3MW until the puff. next: drop target to 1.1e20 |
| May 9 2006 03:02:09:387PM | 1060509016 | Steve Wolfe | Shot#16: drop target to 1.1e20 Plasma, L-mode. Over 3MW clean. Drop target to 1.0e20 |
| May 9 2006 03:27:09:933PM | 1060509017 | Steve Wolfe | Shot#17: drop target to 1.0e20. Put pg3 back to 40V to 0.6sec (like it was earlier when the density was sagging before the RF). Puff off, gain back on during RF Plasma with H-mode. Early injection around .4sec Short H-mode gets to 157kJ, around 3.2MW max, but J faults when it tries to step up. Next: try turning the puff back on (1.0 to 1.25) |
| May 9 2006 03:45:17:183PM | 1060509018 | Steve Wolfe | Shot#18: try turning the puff back on (1.0 to 1.20s), gain off at 1.0. Early disruption .47sec. Looks like a big injection from nose region? I guess we couldn't go the whole day without one of those. Next: lower pg4 and try again |
| May 9 2006 04:12:26:697PM | 1060509019 | Steve Wolfe | Shot#19: pg4 from 23->21ms after the disruption pg3 puff at H-mode time back on (1.0 to 1.20s), NL04 gain off at 1.0. Plasma full length, short H-mode, 155kJ. H->L just before or just after the start of the puff next: 1.7MA, remove the puff, turn the NL04 gain back on. |
| May 9 2006 04:31:55:573PM | 1060509020 | Steve Wolfe | Shot#20: 1.7MA program point to 0.7sec (gain step at 0.8sec) IC_EF4U from +2000 to +2500A aiming for q=3.1 remove the pg3 puff, turn the NL04 gain back on after 1sec Leave pg4 at 21ms. DNB is broken again, disable their gate valve plasma to 1.75sec. 1.7MA, No H-mode. RF ran clean and J went on up to high power! Got to 4MW late. Next: Repeat and try for more power |
| May 9 2006 04:51:43:493PM | 1060509021 | Steve Wolfe | Shot#20: Repeat and try for more power; drop pg4 to 20ms fizzle. Try for one more. |
| May 9 2006 05:23:02:743PM | 1060509022 | Steve Wolfe | Shot#22: PG4 to 18msec Plasma, early injections at .44sec but survived, got H-modes. Last H-mode got to 184kJ, >6e13neuts/sec Max RF power at 4.4MW, almost clean with one J fault at 1.01sec. Best shot of the day. Also the last. |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 09:33:50:723AM | Plasma | Ok | |
| 2 | 09:47:15:287AM | Test | Ok | Gas Test |
| 3 | 10:00:38:083AM | Test | Ok | Gas Test |
| 4 | 10:10:32:927AM | Test | Ok | Gas test |
| 5 | 10:25:08:757AM | Plasma | Ok | |
| 6 | 10:49:10:537AM | Plasma | Ok | |
| 7 | 11:11:54:397AM | Plasma | Ok | |
| 8 | 11:35:37:583AM | Plasma | Ok | |
| 9 | 11:59:33:160AM | Test | Bad | |
| 10 | 12:24:13:083PM | Plasma | Ok | |
| 11 | 12:50:21:320PM | Plasma | Ok | |
| 12 | 01:14:24:240PM | Plasma | Ok | |
| 13 | 01:37:20:960PM | Test | Bad | |
| 14 | 02:03:15:130PM | Plasma | Ok | |
| 15 | 02:25:53:783PM | Plasma | Ok | |
| 16 | 02:53:19:180PM | Plasma | Ok | |
| 17 | 03:16:48:900PM | Plasma | Ok | |
| 18 | 03:39:25:040PM | Plasma | Ok | |
| 19 | 04:02:02:620PM | Plasma | Ok | |
| 20 | 04:24:41:823PM | Plasma | Ok | |
| 21 | 04:47:28:493PM | Plasma | Ok | |
| 22 | 05:12:30:463PM | Plasma | Ok | |