| Miniproposals | ||||||||||||||
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| Operators | |
| Session leader(s): | Robert Granetz,Dennis Whyte,Bruce Lipschultz |
| Physics operator(s): | Steve Wolfe |
| Engineering operator(s): | Bill Cochran,Gary Dekow,Ed Fitzgerald |
| Engineering Operator Run Comment |
| Improved hydrogen-to-deuterium changeover using radiative terminations |
| Session Leader Plans |
| Entered: Feb 10 2005 10:16:56:933PM |
| Author: Robert Granetz |
MP #412 -- Disruptive H/D clean-up Session leaders: D. Whyte (remote), R. Granetz, B. Lipschultz, et al (local) Physics operator: S. Wolfe The goal of this MP is to see if disruptions can be helpful in extracting hydrogen from the walls, thereby accelerating the reduction of the H/D ratio. We have proposed several specific disruption scenarios: 1) Lower null; Initiate the disruption by ramping down Btor until we get a q=2 disruption. This method should dump thermal energy near the strikepoints. It may also result in transition to ELMfree H-mode just before the disruption. 1a) Same initiation method, but try inboard or outboard limited plasmas, and upper null. The idea is to scour all possible surfaces with momentarily high thermal power loads to heat the surfaces and release trapped hydrogen. 2) Use a triggered VDE to initiate the disruption. Positioning the plasma below or above the neutral point just prior to turning off the vertical feedback should determine the direction of subsequent vertical motion. This technique should scour the upper/top surfaces of the divertor. 3) Radiatively triggered disruption using argon puffing. This method will probably not be as effective, because the thermal energy is spread out over the entire vessel surface. Therefore we will probably want to run these discharges at higher current (up to 1.2 MA). Start with (1) at 0.8 MA and nebar=1.2e20 m-3 (nl_04=0.7e20 m-2). For each disruption, monitor the H/D ratio, as well as the post-disruption chamber pressure, and the hydrogen partial pressure measured by the RGA. This requires that the torus pump gate valve remains closed for at least 2 minutes after the discharge. Also monitor halo currents and stresses. After some number of shots (to be determined in consultation with Dennis, Bruce, et al), switch to steps (1a), (2), etc. Based on recent runs, there may be significant difficulties with disruption recovery, so we're not likely to get far along in the experimental plan in just one day. Success would be seeing a trend of reducing H/D during the day. |
| Physics Operators Plans |
| Entered: Feb 10 2005 06:41:51:287PM |
| Author: Steve Wolfe |
| Plan for 11-Feb-2005
MP#412: Disruptive H/D clean-up SL: Dennis Whyte and a cast of locals PO: wolfe Overnight ECDC in D2, bake at 60C Engineering setup: Power systems as on 1050210019 Gas setup: ----------- >>> fill B-Top with 6 psi D2 Hybrid Enabled (PG4) >>> fill B-side lower with 5 psi Ar Hybrid DISabled (PG1) *NOTE Higher pressure* >>> fill B-side upper with 30 psi D2 Hybrid DISabled (PG2) >>> fill (former) C-side with 30 psi D2 Hybrid Enabled (PG3) Torvac Setup: -------------- GV1 closed, Bypass to RGA open Torus gate valves closed in Pulse for 5min after shot Gate valves: ECE (assuming no vac problems) and Z-bolo/shutter open Program- Start from 1050210021 and begin with TF rampdowns to q=2 disruptions. Proceed according to SL plan |
| Session Leader Summaries |
| Entered: Feb 14 2005 01:52:44:360AM |
| Author: Dennis Whyte |
| Session Leader Summary for Friday, 11-Feb-2005
MP#412 Recovery of H/D ratios using disruptions SL: Whyte (remote), Granetz, Blip Physics operator: Wolfe A very successful day for our first attempt at using planned disruptions (or terminations) to improve H/D recovery. We ended up with 18 plasma shots. My compliments to the C-Mod staff on a highly productive day and on the ease of our remote participation from UW-Madison. Highlights --------- - 260 Torr-L of H2 was recovered into the pumps from the walls by exploiting the transient surface heating caused by the disruptions. This is about 25% of the H2 inventory that we estimate needs to be removed from the wall, based on ion beam analysis of the C-Mod tiles. - 190 Torr-L of D2 was also recovered, while ~140 Torr-L of D2 was injected through the gas valves, resulting in a surplus of 50 Torr-L of D2 removed from the walls. Together with the H2 recovery, this provides an important demonstration of fuel inventory control in a metal-clad tokamak (i.e. no tritium retention!). - A fiducial (no planned termination) shot was performed at the end of the run day in order to compare this run to the results at the end of the previous "normal" conditioning day. The H/(H+D) ratio was found to be significantly reduced in the current flattop phase. Considering that initial plasma ops found H/H+D about 50% (#1050207018), perhaps this reduction is consistent with getting about 25% of the H2 out of the wall? shot H/H+D ---- -------- 1050210021 0.47 1050211031 0.3 - B rampdowns consistently produced ohmic H-modes at q_95 ~ 2.7. These resulted in intermediate H2 recovery (~ 7 Torr-L). These H-modes featured large density increases and lower Te. This should produce a termination more dominated by radiation than conduction, and therefore lead to smaller H2 outgassing as compared to VDE disruption that occured with high Te (~2 keV) and lower density. - Post termination fizzles clearly play a role in limiting the effectiveness of the H recovery. A strong correlation was found between the number of fizzles and the quantity of H2 removed in the preceding terminations. This is obviously telling us something important about what controls fizzles, but those details will require more analysis. - Preliminary analysis indicates that the planned terminations are the most efficient method of H2 recovery. The analysis takes into account the number of fizzles following the terminations, etc. to arrive at a H2 recovery efficiency based on a standard 15 minute shot cycle. We include the different termination types, overnight ECDC cleaning (from Thursday night preceding this experiment) and regular (fiducial) discharges taken during the day without terminations. Method Average H2 Recovery rate (Torr-L / shot-cycle) ------- ----------------------------- ECDC 1.6 Fiducial 1.4 q=2 terminations 6.6 VDE terminations 11.6 Conclusion --------- Our general physics expectations were met; radid surface heating caused by the disruptions is an efficient means of removing the hydrogenic species in the near-surface of the wall. Disrupting every shot did not cause unwanted side-effects to the overall operation of the device, with the exception of current rampup "fizzles" in proceeding discharges. The general goals of the experiment were met with substantial H2 recovery and reduction of H/H+D. In addition we obtained net depletion of hydrogenic fuel from the Mo wall by consistently using planned terminations. an imporant demonstration of H/D/T control for a burning plasma experimnt. |
| Physics Operator Summaries |
| Entered: Feb 13 2005 11:51:41:330AM |
| Author: Steve Wolfe |
| Physics Operator Summary for Friday, 11-Feb-2005
MP#412 Disruptive acceleration of H/D reduction SL: Whyte (remote), Granetz, Blip PO: wolfe EO: Cochran,Dekow,Fitzgerald We got more done than I expected, actually getting through most of steps 1, 1a, and 2 of the SL run plan and deciding to do 1MA VDE's instead of upper null or the radiative disruptions. MY pre-run prediction was that we would only get seven successful startups, and we ended up getting 18. Recovery from 800kA disruptions was easier than in the past few days, handled by reducing the pg4 puff. We actually got to the point of needing to raise the puff back (from 9ms) to avoid bouncers. However, once we went to 1MA VDE's, which seemed to give the biggest effect on released gas, the recovery also got worse, back to three fizzles before another startup. However, even in this case I ended up chasing the fill both down and up. Following an initial non-disruptive shot, we spent several shots trying to get a tf rampdown to get to a q<2 disruption during current flattop. It turned out that the maximum tf ramp-down rate was only getting us down by 1.7sec or so. We then extended the flattop to 1.8sec on shot 4, which was successful in generating a low q disruption, following an H-mode transition around 1.4sec . Shots 5-8 terminated earlier, with VDE's and one possible injection, all in lower null with different strike points. We then went to the inner wall on shot 9 and got another good low-q disruption. For shot 10 we kept the plasma diverted until 1.66sec, and then moved fast to the inner wall to try to get the disruption while still in H-mode, or at least within a confinement time of the H->L. To my amazement this worked. Shot 11 used the same technique but with the plasma a little higher up on the inner wall, and again was successful in disrupting in H-mode, with about 40kJ. Shots 12 and 13 were SNL disruptions approaching the outer limiter, the second at about 3mm outer gap, again in H-mode at the disruption. This completed the low q part of the run (they decided not to try upper null), and we moved on to VDE's. The technique was to turn off the gains on zcur3 and let it go. Shot 14 was an upward going vde, although the programmed zcur was -9mm. To this point we had had only one fizzle (shot 7); I had dropped pg4 to 9msec at shot 8. Shot 15 was another fizzle, but it was an outboard bouncer so I raised pg4. Shot 16 had no gas at all and was a dud of course; it looked like we hadn't gotten the permissive from the PLC. Shot 17 was another outboard fizzle, and for shot 18 I raised pg4 back to 16msec. This was successful, butwas the start of an unstable cycle of chasing the pre-puff. Shot 20 was another successful 800kA VDE, again moving down. It was then decided to try VDE's at 1MA, and the disruption recovery really got bad. Successful 1MA VDE's were shots #22 and #26. Interestingly, these went to a VDE before the gain switch-off, just on the zcur eexcursion down to -3cm which was intended to insure that they went down (they did). Finally, after 3 fizzles and a no-power shot, the last shot #31 was a successful repeat of shot 1, full length 800kA lower null. The session leaders seemed relatively happy with the run, although it still isn't clear whether the disruptive technique for cleaning up and removing hydrogen is superior to just running plasmas. It seemed that the vde's landing on the top of the outer divertor were most efficient at evolving gas. The H/D at the end of the run was lower than at the end of runs earlier this week. Other problems: The event server died and required a restart of the cycle. The big board failed to update about six times during the run. The alternator excitation did not come on for shot#28, resulting in a no power shot. ON a number of the long Bt-rampdown shots, the EFIT zmaxis showed the plasma moving up during the shot, although the DPCS and Ian's fluxihh zcur showed Z looking pretty constant. This needs to be investigated. Scorecard ---------- Tests, no-power 1 Duds 1 (no gas) Fizzles 11 Plasmas 18 ---------- -- Shots 31 |
| Session Leader Comments | |||
| Feb 11 2005 12:50:36:000PM | 1050211001 | Robert Granetz | Nominal lower single null, full-length plasma. Ip=0.8 MA, Btor=5.4 T. H/(H+D)=0.14 Total post-shot pressure: ? Torr (gauge on big board). RGA post-shot partial pressures: Mass Pressure (Torr) 2 3.1e-8 3 8.4e-8 4 1.3e-7 Next shot: low q disruption by ramping down Btor, starting the ramp at t=0.6 s. |
| Feb 11 2005 12:51:47:500PM | 1050211002 | Robert Granetz | Disrupted, but not until Ip was ramping down. H/(H+D)=0.15 Total post-shot pressure: 9.8e-4 Torr (gauge on big board). RGA post-shot partial pressures: Mass Pressure (Torr) 2 7.1 e-8 3 1.76e-7 4 1.86e-7 Next shot: ramp down Btor faster. |
| Feb 11 2005 12:44:41:567PM | 1050211003 | Robert Granetz | Disrupted at t=1.69 s, still in Ip rampdown. This was actually an upward VDE. There were several little ELMfree H-modes starting at t=1.35 s H/(H+D)=0.19 Total post-shot pressure: 1.1e-3 Torr (gauge on big board). RGA post-shot partial pressures: Mass Pressure (Torr) 2 1.1e-7 3 2.3e-7 4 2.0e-7 Next shot: extend flattop to 1.8 s. |
| Feb 11 2005 01:04:37:153PM | 1050211004 | Robert Granetz | Disrupted at t=1.70 s, during flattop. Good shot. q95=1.9 and Btor=2.0 T at the disruption. More ELMfree H-modes. H/(H+D)=0.21-0.25 Total post-shot pressure: 1.7e-3 Torr (gauge on big board). RGA post-shot partial pressures: Mass Pressure (Torr) 2 1.94e-7 3 3.51e-7 4 2.6 e-7 Next shot: lower the strikepoint on the vertical outer divertor face. |
| Feb 11 2005 01:17:33:070PM | 1050211005 | Robert Granetz | Disrupted at t=0.7 s, due to vertical problem. Probably related to the change in X-pt location. At the disruption, the plasma was just about touching the upper part of the inboard divertor, so we've presumably just scoured off another part of the surface, so this was a useful shot. H/(H+D)=0.27 Total post-shot pressure: ? Torr (gauge on big board). Gauge tripped off. RGA post-shot partial pressures: Mass Pressure (Torr) 2 3.6e-7 3 5.2e-7 4 3.3e-7 Next shot: try modifying the x-pt programming to hit the lower vertical face of the outboard divertor. |
| Feb 11 2005 01:32:37:050PM | 1050211006 | Robert Granetz | Disrupted at t=0.60 s. Equilibrium had low outboard strikepoint, but then limited on outboard shelf just before the disruption. So I think we scoured the shelf, and we got a huge gas puff. H/(H+D)=0.28 Total post-shot pressure: ? Torr (gauge on big board). Gauge tripped off. RGA post-shot partial pressures: Mass Pressure (Torr) 2 1.16e-6 3 1.28e-6 4 4.8 e-7 Next shot: try again for strikepoint low on vertical face. This time, fatten the plasma so that the elongation is not too high. |
| Feb 11 2005 01:42:10:467PM | 1050211007 | Robert Granetz | Fizzle. H/(H+D)= no plasma Total post-shot pressure: 9.8e-5 Torr (gauge on big board). RGA post-shot partial pressures: Mass Pressure (Torr) 2 1.3 e-8 3 1.6 e-8 4 2.3 e-8 Next shot: try again; strikepoint on lower part of vertical outboard face |
| Feb 11 2005 02:04:30:770PM | 1050211008 | Robert Granetz | Good disruption at t=1.34 s, at q=2.7. Don't know what caused that disruption, but the strikepoint was in a good position on the outboard H/(H+D)=0.30 Total post-shot pressure: 1.4e-3 Torr (gauge on big board). RGA post-shot partial pressures: Mass Pressure (Torr) 2 1.8 e-7 3 2.6 e-7 4 2.5 e-7 Next shot: Limit on inboard wall at t=1.2 s and continue the field rampdown to get a disruption. |
| Feb 11 2005 02:17:48:450PM | 1050211009 | Robert Granetz | Disrupted at t=1.68 s at q95=1.9. Inboard wall limited. Wp=20 kJ, since we're not in H-mode. H/(H+D)=0.28-0.34 Total post-shot pressure: 1.4e-3 Torr (gauge on big board). RGA post-shot partial pressures: Mass Pressure (Torr) 2 1.53e-7 3 2.26e-7 4 1.67e-7 Next shot: try limiting within 10-20 ms before the disruption so that the plasma might have H-mode thermal energy. |
| Feb 11 2005 02:31:37:753PM | 1050211010 | Robert Granetz | Disrupted exactly as we wanted, still with H-mode energy (40 kJ) as it limits and disrupts. Good job, Steve! H/(H+D)=0.30-0.36 Total post-shot pressure: 1.4e-3 Torr (gauge on big board). RGA post-shot partial pressures: Mass Pressure (Torr) 2 1.66e-7 3 2.31e-7 4 1.59e-7 Next shot: similar inboard limited, except 2 cm higher up on the wall. |
| Feb 11 2005 02:49:00:730PM | 1050211011 | Robert Granetz | Another inboard wall disruption, with 40 kJ (H-mode energy), this time several cm higher. H/(H+D)=0.32-0.33 Total post-shot pressure: 1.3e-3 Torr (gauge on big board). RGA post-shot partial pressures: Mass Pressure (Torr) 2 1.61e-7 3 2.36e-7 4 1.62e-7 Next shot: Now try scouring the outer limiter. Rather than touching the limiter, first try just decreasing the outer gap to 8 mm (from 12 mm). So it should remain lower single null, be in H-mode, and disrupt at q=2. |
| Feb 11 2005 03:04:59:393PM | 1050211012 | Robert Granetz | SNL disruption at t=1.74 s. Outer gap=8 mm at disruption, just H/(H+D)=0.28-0.37 Total post-shot pressure: ? Torr (gauge on big board). RGA post-shot partial pressures: Mass Pressure (Torr) 2 1.75e-7 3 2.41e-7 4 1.5 e-7 Next shot: Decrease outer gap to 3 mm. |
| Feb 11 2005 03:16:30:850PM | 1050211013 | Robert Granetz | Disruption, outer gap=3 mm, as desired. H/(H+D)=0.30-0.34 Total post-shot pressure: 1.3e-3 Torr (gauge on big board). RGA post-shot partial pressures: Mass Pressure (Torr) 2 2.2 e-7 3 2.85e-7 4 1.86e-7 Next shot: Start the VDE part of the run plan. Constant Btor. Start with downward going VDE at t=1.0 s. |
| Feb 11 2005 03:29:39:043PM | 1050211014 | Robert Granetz | Disruption at t=1.02 s. This one went up. More gas released, but not a huge amount. H/D from RGA post-disruption was higher than the previous shots. H/(H+D)=0.28 Total post-shot pressure: 1.7e-3 Torr (gauge on big board). RGA post-shot partial pressures: Mass Pressure (Torr) 2 1.6 e-7 3 1.5 e-7 4 3.14e-8 Next shot: push plasma downwards just before the intentional VDE so that we hit the outboard shelf. |
| Feb 11 2005 03:51:55:240PM | 1050211015 | Robert Granetz | Fizzle. H/(H+D)= no plasma Total post-shot pressure: ? e-5 Torr (gauge on big board). RGA post-shot partial pressures: Mass Pressure (Torr) 2 6.1 e-9 3 7.6 e-9 4 4.4 e-9 Next shot: try again. |
| Feb 11 2005 03:51:34:940PM | 1050211016 | Robert Granetz | Dud. The PLC gas-enable was off. H/(H+D)= no plasma Total post-shot pressure: 2.0e-5 Torr (gauge on big board). RGA post-shot partial pressures: Mass Pressure (Torr) 2 3 4 Next shot: try, try again |
| Feb 11 2005 04:07:21:540PM | 1050211017 | Robert Granetz | Fizzle. |
| Feb 11 2005 04:18:48:950PM | 1050211018 | Robert Granetz | Disrupted at t=1.03 s. Hit the outboard shelf, as desired. Wp=30-35 kJ. Lots of gas, just like shot 006, which was essentially similar. H/(H+D)=0.25 Total post-shot pressure: ? Torr (gauge on big board). Gauge tripped off. RGA post-shot partial pressures: Mass Pressure (Torr) 2 5.5 e-7 3 6.5 e-7 4 3.5 e-7 Next shot: repeat |
| Feb 11 2005 04:29:46:830PM | 1050211019 | Robert Granetz | Fizzle. H/(H+D)= no plasma Total post-shot pressure: 6.0e-5 Torr (gauge on big board). RGA post-shot partial pressures: Mass Pressure (Torr) 2 3 4 Next shot: try again for downward VDE to hit the outboard shelf again. |
| Feb 11 2005 04:48:09:010PM | 1050211020 | Robert Granetz | Disruption, VDE went down to the outboard shelf, as desired. Lots of gas again. H/(H+D)=0.27 Total post-shot pressure: ? Torr (gauge on big board). Gauge tripped off. RGA post-shot partial pressures: Mass Pressure (Torr) 2 6.3 e-7 3 7.4 e-7 4 3.3 e-7 Next shot: same downward VDE, but raise Ip to 1.0 MA |
| Feb 11 2005 04:56:51:513PM | 1050211021 | Robert Granetz | Fizzle. H/(H+D)= no plasma Total post-shot pressure: 1.6e-4 Torr (gauge on big board). RGA post-shot partial pressures: Mass Pressure (Torr) 2 3 4 Next shot: try again at 1.0 MA |
| Feb 11 2005 05:16:48:757PM | 1050211022 | Robert Granetz | 1.0 MA VDE disruption on outboard shelf. Wp was only 20 kJ. H/(H+D)=0.27 Total post-shot pressure: ? Torr (gauge on big board). Gauge tripped off. RGA post-shot partial pressures: Mass Pressure (Torr) 2 6.8 e-7 3 6.6 e-7 4 2.7 e-7 Next shot: repeat, but lower the elongation slightly. |
| Feb 11 2005 05:24:46:993PM | 1050211023 | Robert Granetz | Fizzle. H/(H+D)= no plasma Total post-shot pressure: 8.5 e-5 Torr (gauge on big board). RGA post-shot partial pressures: Mass Pressure (Torr) 2 3 4 Next shot: try again at 1.0 MA |
| Feb 11 2005 05:37:52:030PM | 1050211024 | Robert Granetz | Fizzle. H/(H+D)= no plasma Total post-shot pressure: 6.5e-5 Torr (gauge on big board). RGA post-shot partial pressures: Mass Pressure (Torr) 2 3 4 Next shot: try 1.0 MA again. |
| Feb 11 2005 05:43:58:390PM | 1050211025 | Robert Granetz | Fizzle. |
| Feb 11 2005 06:08:36:070PM | 1050211026 | Bruce Lipschultz | shot 26: . . . . . . . . . . . . . . . . . . . . Disrupted at t=0.94 s, still in Ip rampdown. This was actually an downward VDE. H/(H+D)=0.33 Total post-shot pressure: 22 mTorr (MKS gauge on machine). RGA post-shot partial pressures: Mass Pressure (Torr) 2 1.98e-6 3 1.63e-6 4 5.23e-7 Next shot: repeat |
| Feb 11 2005 06:12:37:417PM | 1050211027 | Bruce Lipschultz | shot 27: Fizzle |
| Feb 11 2005 06:26:27:923PM | 1050211028 | Bruce Lipschultz | shot 28: alternator not excited |
| Feb 11 2005 06:31:45:127PM | 1050211028 | Bruce Lipschultz | shot 28: alternator not excited |
| Feb 11 2005 06:33:17:957PM | 1050211029 | Bruce Lipschultz | shot 29: fizzle |
| Feb 11 2005 06:44:35:493PM | 1050211030 | Bruce Lipschultz | shot 30: fizzle |
| Feb 11 2005 07:03:28:350PM | 1050211031 | Bruce Lipschultz | shot 31: no disruption - reloaded shot 1 as fiducial H/(H+D)=0.31 Total post-shot pressure: 0.86 mTorr (MKS gauge on machine). RGA post-shot partial pressures: Mass Pressure (Torr) 2 6.9e-8 3 8.8e-8 4 4.4e-8 - |
| Physics Operator Comments | |||
| Feb 11 2005 10:09:42:453AM | Steve Wolfe | Setting up the first shot:
Import segment 2 from 1050210021 Extend nl04 program to 1.4 add a little early pg3 in seg2 remove A-coil point at 10sec Using seg1 from yesterday increase pg3 early points to 35V increase pg4 from 10msec to 20msec for 1st shot | |
| Feb 11 2005 10:36:15:180AM | Steve Wolfe | Setting up for later shots:
Load seg3 from 1031125020(SNU case) recalc Ip predictor and change offset to -70000 copy oh voltage program from seg2 clearin has a slight ramp, -.015 to -.01 and zero offset. actual left gap is .01 which corresponds to clearin=0.0 This implies the offset should be .015m*8e5a=12e3 a-m, similar to the lower null case. Go ahead and put in 12700 and draw clearin straight across at 0.0 and see what we get. Also move the limited start and end by .015 change nl04 program to 5e19. Do a build_seg. NOTE- CHANGE SEG3 FROM ASYNC TO SYNC!!! | |
| Feb 11 2005 10:52:32:797AM | Steve Wolfe | Setting up for later shots:
Import Seg4 from 1050210014/seg2 and increase RCUR by .005 Note that clearin is -.02, which nominally would be dsep=-.01; we're actually getting dsep=-.005 according to efit. Load wire of NL04 from seg2 Build seg | |
| Feb 11 2005 11:00:03:700AM | Steve Wolfe | Load shot into model.
one factor screen and two wires complain while I'm tickling things, fix the 10sec point on acoil in seg3 Load again; no whines. | |
| Feb 11 2005 12:18:57:890PM | 1050211001 | Steve Wolfe | Shot#1: Program for LSN, nl04 5e19, 800kA standard
Plasma full length. Good startup, br a little negative Next shot: program tf to ramp down from 0.6 to zero at 1.9sec |
| Feb 11 2005 12:23:47:280PM | 1050211002 | Steve Wolfe | Shot#2: program tf to ramp down from 0.6 to zero at 1.9sec
expect q=2 disruption around 1.4sec. disrupts in rampdown at 1.7sec Need to rampdown faster. |
| Feb 11 2005 12:49:29:110PM | 1050211003 | Steve Wolfe | Shot#3: Need to rampdown faster.
Change tf rampdown from 0.5 to 1.5sec decrease pg4 from 20ms to 15ms Plasma, disrupted at 1.7sec. Looks like we're at the max tf rampdown rate. H-mode at 1.3sec. PF Breaker pulled out after the disruption. Next shot: try extending flattop to 1.8sec |
| Feb 11 2005 01:07:06:480PM | 1050211004 | Steve Wolfe | Shot#4:try extending flattop to 1.8sec
disrupted in flattop at 1.70sec H-mode at about 1.4sec next shot: pg4 to 12msec zxl -2cm, rxl -2cm |
| Feb 11 2005 01:19:49:477PM | 1050211005 | Steve Wolfe | Shot#5: pg4 to 12msec
zxl -2cm, rxl -2cm Disruption at 0.7sec Shouldn't have moved rxl that far. It was on the nose and also had a vertical problem. next shot: rxl back to zero pg4 to 10ms |
| Feb 11 2005 01:29:06:220PM | 1050211006 | Steve Wolfe | Shot#6:rxl back to zero
pg4 to 10ms Another early disruption. Still vertically unstable. n/nc =1.5 at the disruption. Try to decrease elongation with this strike point |
| Feb 11 2005 01:38:27:170PM | 1050211007 | Steve Wolfe | Shot#7:Try to decrease elongation with this strike point
Zcur -.009 to -.015 clearin .01 to .005 increase pg3 between .2 and .4sec fizzle |
| Feb 11 2005 01:56:27:633PM | 1050211008 | Steve Wolfe | Shot#8:Try again to decrease elongation with this strike point
pg4 to 9msec zcur -.009 to -.015 clearin .01 to .005 increase pg3 between .2 and .4sec plasma to 1.3sec No vertical problem this time. q95=2.7 looks like an injection |
| Feb 11 2005 02:11:21:190PM | 1050211009 | Steve Wolfe | Shot#9:move to inner wall between 1.1 and 1.2
clearin to -.02, rcur to .648 (still using seg2) plasma to 1.7sec, that's the q limit density and halpha start up at 1.17sec I think that one did what it was told. |
| Feb 11 2005 02:24:43:070PM | 1050211010 | Steve Wolfe | Shot#10:Try to time the move to limiter:
step change in RCUR and CLEARIN at 1.66sec (same values as before) plasma to 1.69sec, might have been still in H-mode? last efit is at 1.8mm off the wall. |
| Feb 11 2005 02:37:33:210PM | 1050211011 | Steve Wolfe | Shot#11:zcur to 0, zxl to 0
leave the jog at 1.66. The idea is to hit a different place on the inner wall plasma to 1.68 and in H-mode near the end. Again the last efit is 1.7mm from the wall |
| Feb 11 2005 02:59:52:720PM | 1050211012 | Steve Wolfe | Shot#12: Go back to shot 8 and move rcur out by 2mm
Trying to get an outer gap of 8mm, no jog, still ramping the field down. plasma to 1.74sec Outer gap is 8mm in H-mode, only at 1cm in L-mode. |
| Feb 11 2005 03:11:42:833PM | 1050211013 | Steve Wolfe | Shot#13: Rcur to .6625, aiming for 3mm gap in H-mode
phase plasma to 1.70 sec, outer gap about 3mm in H-mode 7mm in L-mode |
| Feb 11 2005 03:25:58:760PM | 1050211014 | Steve Wolfe | Shot#14: They want to trigger a vde.
reload shot 1, turn off zcur 3 gain at 1.0sec Disrupts at 1.02sec, Went up! next shot: move plasma down before we kill the gain |
| Feb 11 2005 03:34:28:373PM | 1050211015 | Steve Wolfe | Shot#15: move plasma down before we kill the gain
zcur down to -.03 between .90 and .95, kill z3 gains at 1.0 fizzle |
| Feb 11 2005 03:52:16:910PM | 1050211016 | Steve Wolfe | Shot#16: 15 bounced outside, pg4 from 9 to 11msec
move plasma down before we kill the gain zcur down to -.03 between .90 and .95, kill z3 gains at 1.0 dud. Power supplies all there. No gas puff. Looks like no permissive on any valve, there is no command signal on either pg4 or pg3. DPCS sent them out, either the permissive failed or the amplifier is off. next shot: watch the permissive on the plc screen |
| Feb 11 2005 04:07:26:760PM | 1050211017 | Steve Wolfe | Shot#17: pg4 from 9 to 11msec
move plasma down before we kill the gain zcur down to -.03 between .90 and .95, kill z3 gains at 1.0 fizzle again, gas enable came on in pulse ok. Big board failed to update again; third time today Still bouncing. raise pg4 to 16msec |
| Feb 11 2005 04:16:38:373PM | 1050211018 | Steve Wolfe | Shot#18: pg4 from 11 to 16msec
Still trying to move plasma down before we kill the gain zcur down to -.03 between .90 and .95, kill z3 gains at 1.0 plasma (finally!) downward vde as we wanted. startup looks ok. next shot: drop pg4 by 1msec; do something different with plasma? |
| Feb 11 2005 04:27:22:313PM | 1050211019 | Steve Wolfe | Shot#19: pg4 from 16 to 15msec
repeat of 18. fizzle. Needed more of a drop on pg4 it looks like. We may be having a problem with the event server again, No voice in init until Gary re-started the announce, no scope updates. slow actions. |
| Feb 11 2005 04:42:18:947PM | 1050211020 | Steve Wolfe | Shot#20: pg4 from 15 to 12 msec
repeat of 18. plasma to 1.02sec, looks similar to 18. slightly late breakdown, 7.7msec next shot: pg4 to 11msec, go to 1MA |
| Feb 11 2005 04:53:49:027PM | 1050211021 | Steve Wolfe | Shot#21: pg4 from 12 to 11msec
go to 1MA, still aiming for a vde at 1sec also, put back some pg3 between .2 and .4 fizzle. slow current rise, too much bz; bd time is ok, 5.5ms next shot back to 9msec |
| Feb 11 2005 05:14:39:800PM | 1050211022 | Steve Wolfe | Shot#22: pg4 from 11 to 9msec
go to 1MA, still aiming for a vde at 1sec also, put back some pg3 between .2 and .4 plasma disrupted at .917, before turning off z3 gain. n/nc = 1.29, li=1.4, outer gap is a little bigger (2cm) startup is running a little outside |
| Feb 11 2005 05:21:13:337PM | 1050211023 | Steve Wolfe | Shot#23: move rcur out 2mm, to lower n/nc
otherwise repeat. fizzle. chokes again; I could try 8msec on pg4 |
| Feb 11 2005 05:32:25:200PM | 1050211024 | Steve Wolfe | Shot#24: pg4 to 8msec!
move rcur out 2mm from shot 21 to lower n/nc otherwise repeat. another fizzle. went too far on pg4, this one bounces outside. back up to 15msec |
| Feb 11 2005 05:45:02:627PM | 1050211025 | Steve Wolfe | Shot#25: pg4 to 15msec
move rcur out 2mm from shot 22 to lower n/nc otherwise repeat. fizzled again, still going out. next shot: raise pg4 to 20msec; this is in an unstable feedback loop |
| Feb 11 2005 06:00:01:537PM | 1050211026 | Steve Wolfe | Shot#26: pg4 to 20msec
move rcur out 2mm from shot 22 to lower n/nc otherwise repeat. fizzled again, still going out. While we're waiting, request Tommy to raise the bside-lower Ar pressure to 30psi; if we're going to use it may as well get a lot. plasma to .926, apparently I didn't fix the instability but it went down anyway. It's a good repeat of 22. |
| Feb 11 2005 06:10:27:480PM | 1050211027 | Steve Wolfe | Shot#27: pg4 to 10msec
Another repeat of 1MA vde actually, another repeat of a fizzle. |
| Feb 11 2005 06:24:07:970PM | 1050211028 | Steve Wolfe | Shot#28: repeat with pg4 to 12msec, a total guess as to how
far it has recovered. No alternator excitation. We'll do a no power shot |
| Feb 11 2005 06:33:27:737PM | 1050211029 | Steve Wolfe | Shot#29: repeat with pg4 to 12msec, a total guess as to how
far it has recovered. Since we'll have gone an extra 7 or 8 minutes this may not be enough. fizzle. Still a slow current rise, just leave it alone. next shot: reload of shot 1 |
| Feb 11 2005 06:46:10:930PM | 1050211030 | Steve Wolfe | Shot#30: reload seg2 of shot 1, leave pg4 at 12msec
And yet another fizzle. outside, needed more gas this time. next shot: pg4 to 18msec and hope |
| Feb 11 2005 06:59:11:130PM | 1050211031 | Steve Wolfe | Shot#31: pg4 to 18msec and hope
plasma full length, left a good one on the drum. almost lost in startup, long hesitation, but it made it. END OF RUN |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 12:07:06:987PM | Plasma | Ok | |
| 2 | 12:20:13:170PM | Plasma | Ok | |
| 3 | 12:34:18:773PM | Plasma | Bad | EF1L IOC Type 1 Flt |
| 4 | 12:50:52:563PM | Plasma | Ok | |
| 5 | 01:08:05:183PM | Plasma | Ok | |
| 6 | 01:21:52:863PM | Plasma | Ok | |
| 7 | 01:35:34:827PM | Plasma | Ok | |
| 8 | 01:49:40:183PM | Plasma | Ok | |
| 9 | 02:07:23:677PM | Plasma | Ok | |
| 10 | 02:20:46:723PM | Plasma | Ok | |
| 11 | 02:33:24:457PM | Plasma | Ok | |
| 12 | 02:54:35:687PM | Plasma | Ok | |
| 13 | 03:07:19:737PM | Plasma | Ok | |
| 14 | 03:20:10:227PM | Plasma | Ok | |
| 15 | 03:32:50:280PM | Plasma | Ok | |
| 16 | 03:45:38:017PM | Plasma | Ok | |
| 17 | 03:58:06:397PM | Plasma | Ok | |
| 18 | 04:10:38:183PM | Plasma | Ok | |
| 19 | 04:23:18:313PM | Plasma | Ok | |
| 20 | 04:37:21:130PM | Plasma | Ok | |
| 21 | 04:50:20:887PM | Plasma | Ok | |
| 22 | 05:02:52:267PM | Plasma | Ok | |
| 23 | 05:17:16:600PM | Plasma | Ok | |
| 24 | 05:29:46:777PM | Plasma | Ok | |
| 25 | 05:42:06:280PM | Plasma | Ok | |
| 26 | 05:56:08:707PM | Plasma | Ok | |
| 27 | 06:08:46:120PM | Plasma | Ok | |
| 28 | 06:21:22:233PM | Plasma | Bad | Alternator exicitation fault |
| 29 | 06:29:57:347PM | Plasma | Ok | |
| 30 | 06:42:21:570PM | Plasma | Ok | |
| 31 | 06:54:42:147PM | Plasma | Ok | |