| Miniproposals | ||||||||||
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| Operators | |
| Session leader(s): | Martin Greenwald,Martin Greenwald |
| Physics operator(s): | Jim Irby |
| Engineering operator(s): | Bill Cochran,Gary Dekow |
| Engineering Operator Run Comment |
| MP274 H/D Changeover and MP255 EDA boundary in hydrogen H-modes, SL: Gr |
| Session Leader Plans |
| Physics Operators Plans |
| Session Leader Summaries |
| Entered: Jul 7 2004 03:49:24:493PM |
| Author: To Be Determined |
| MP274 H/D Changeover (Particle control task force) & MP 255 Hydrogen H-modes (H-mode task force) Session Leader - Greenwald Phys Op - Irby ============================ A fairly successful day, we got good data for both proposals. ................................................. MP274 H/D Changeover - Quantify the interaction between the plasma and wall hydrogen/deuterium inventories. Background: AT operation on C-Mod will require lower densities than our standard H-modes. To achieve this, we will require some form of active particle control (for example, a cryopump). This active control must compete quantitatively with the pumping and outgassing of the walls. Thus, it is important that we have a measure of the effective particle inventory contained by the walls and the rate at which this inventory is exchanged during normal operation. While the walls potentially hold an inventory which is 2 orders of magnitude larger than that in the plasma, past experience suggests that only a small fraction of the total wall inventory is involved in this exchange. Factors effecting the interaction between gas in the wall and the plasma include the area "wetted" by the plasma, depth of particle depostion in the wall, and the nature of the binding between the wall and the neutral molecules. Approach: Start with a standard shot. Change all filling and puffed gasses from D$_2$ to H$_2$ while running constant discharges. Look for H/D ratio in plasma, residual gas, etc. When the plasma is measured to be 90-95\% hydrogen, reverse the process by switching the gas back to D$_2$. If time permits, repeat the experiment once the H levels fall to the 5-10\% level. We ran shots with nebar ~ 2e20 and Ip ~ 1 MA. We use the Halpha/Dalpha spectra to get the isotope ratio in the plasma. Results: Before the changeover the ratio R==H/(H+D) = 2.5% This rose to 30% on first shot with H2 puffing. After 5 shots R rose to 65%. The total H2 puffed on each shot was approximately 50 torr liters. The wall inventory is estimated to be about 300 times larger so a puff with 0.3% of wall inventory - changes over 30% of plasma ions. The characteristic turnover time (R/dR/dt) was 3 seconds for the first shot then slowed down gradually for later shots reaching maybe 30 seconds after 7 shots. Thus the changeover is not at all exponential. When we switched mini proposals, we ran much lower densities - the required puff rate was about 1/3 of that for the changeover experiments. The result was that R dropped immediately to 60% and rose at a slower rate - perhaps a factor of 3. Thus (not surprisingly) the puff rate is an important factor in the rate of turnover. (Since the algorithm used to calculate the H/D ratio is optimized for a small H fraction, there may be small (10-20%) errors in the computed H/D fraction. If so, we should be able to fix that. ............................... MP255 Hydrogen H-modes - ELMfree EDA Boundary Look for isotope effect on ELMfree EDA boundary Background Resistive ballooning has been predicted to be a dominant mode in the plasma edge. Recent simulations by Rogers and Drake have shown that this can take the form of coherent oscillations with k$_\theta \sim $ k$_r \sim 2\pi/\delta$ where $\delta$ is the pedestal width. In the resistive ballooning dispersion relation, $m_i^{1/2}/q$ is a stabilizing term. This could explain the q dependence we see in the EDA/ELMfree boundary. High q would make the term smaller, destabilize resistive ballooning and lead to EDA. If this hypothesis is correct, hydrogen discharges, with m$_i$ = 1 should stay in EDA down to lower q. All things being equal (profiles etc.) the q threshold, which is in the range 3.5-4 for deuterium should drop to the range 2.5-3. A clear explanation for the physics origin of EDA would allow us to evaluate its utility in future machines. This experiment would also allow us to investigate the isotope scaling of the L/H threshold, pedestal width, fluctuation character, global confinement, impurity confinement, etc. Approach: This experiment requires running H-modes in hydrogen. With no well tested ICRF heating scenario in majority hydrogen discharges, it is probably best to rely on ohmic heating. We would start with a discharge like 990831015 except with slightly higher current. We can probably go to 0.9-0.95 MA without hitting the low q limit. (It may be necessary to increase the elongation to allow higher currents.) Once the L/H threshold is reached, we look for the EDA/ELMfree boundary by scanning up slowly in q. (It is also possible that we will always be in EDA down to the lowest possible q values.) Results: On shots 21, 22, 23, and 25 we got decent (though brief) ohmic H-modes. Bt was dropped systematically. During the H phase, q95 was roughly 2.9, 2.8, 2.5 and 2.6 respectively for these 4 shots. All 4 showed clear signs of EDA based on Halpha, radiation and the presence of the quasi-coherent mode on PCI, reflectometry and the A side probe. Shot 25 showed clear dithers between EDA and ELMfree. During this part of the run, the Hydrogen fraction never rose much above 0.6 - thus meff dropped to 1.4. If the threshold depended on sqrt(meff) this would have dropped from 1.414 to 1.17 roughly a change of 20%. For a nominal q threshold in the range 3-4 for D, we would expect a drop to 2.5-3.3 for the mix in this experiment. On the surface, this would tend to confirm a dependence on q95 in the proposed direction. However, we need to check that the profiles were otherwise similar. |
| Physics Operator Summaries |
| Entered: Jul 7 2004 04:37:11:457PM |
| Author: To Be Determined |
| Engineering Setup for 1000622 MP 274: H/D Changeover MP 255: EDA boundary in hydrogen H-modes --- attempted as time allows Session Leader: Greenwald Physics Operator: Irby Engineering Operators: G. Dekow/B. Cochran ECDC overnight in D2, stopping 1-2 hours before run. Run begins at 9:00 and ends at 17:00. Power system setup: Same as for 1000616001 Set OH1, OH2U and OH2L fizzle delays at 300ms Set TF fizzle delay at 400 ms Gas setup: B-Top 6 psi D2 Hybrid Enabled B-side lower 1 psi Argon Hybrid DISABLED C-side 30 psi D2 Hybrid Enabled J-bottom leave as is Hybrid DISABLED The following Gate Valves should be ENABLED ECE, VUV No RF power will be needed for either MP274 or MP255 Main emphasis will be on MP274. We will start off with a "standard" discharge in D2 and then switch all source gas to H2. Result: We had a great deal of difficulty getting reliable startups early in the run. After tweaks of gas, bz, and br, we finally got a series of good discharges starting on shot 9. After the H to D had risen to greater than 3, Martin asked to start the ohmic h-modes in hydrogen run. Shot 1000518007 was loaded, but the plasma only lasted about 0.66 seconds. Several shots were required to get a nearly full length discharge (turned off argon??, shot 19). Steve noted on shot 23 that the new Ip offsets had not been added on 5/18 so that explained why Ip was not following demand. I think we got very good data today for both the D to H change over and the ohmic h-modes in hydrogen experiments. The last shot of the day (26) was a gas test. Score: tests 1 CAMAC faults 1 duds 1 fizzles 4 plasmas 19 total 26 ---------------------------------------------------------------------------- 1000622xxx irby PHYSICS_OPERATOR Jun 22 2000 8:10:24:436AM . . . . . . . . . . . . . . . . . . . . Yesterday we had a leak on f-hor during most of the run. It was purged with argon after the run and the missing heaters re-installed. We ran overnight ECDC in D2 until about 07:00. This morning Tommy switched the purge back to pump and the mass 28 is back down to an acceptable level (7e-9). Did load/clean with no changes yet from last shot from yesterday Did coldstart: rtnode -- data loaded, A matrix responds rtnode -- data loaded, M matrix responds rtnode -- data loaded, PID matrix responds RT_NODE Done Startup from yesterday: shot: 1000621020 Gas pretty low, but assume it will be a little higher on the first shot. ---------------------------------------------------------------------------- 1000622xxx irby PHYSICS_OPERATOR Jun 22 2000 8:45:34:343AM . . . . . . . . . . . . . . . . . . . . Loaded from 1000616001 load/clean Note that the ef4 settings yesterday was -1295 vs -1260 for 6/16. So we may have a Bzo problem on the first shot. Prefill was from -0.52 to -0.50 in both cases. ---------------------------------------------------------------------------- 1000622001 irby PHYSICS_OPERATOR Jun 22 2000 9:05:56:280AM . . . . . . . . . . . . . . . . . . . . Base pressure: 3.1e-7 Torr with GV3 closed. Dud Gas too low: ---------------------------------------------------------------------------- 1000622002 irby PHYSICS_OPERATOR Jun 22 2000 9:21:29:250AM . . . . . . . . . . . . . . . . . . . . Added 5 ms to prefill: -0.52 to -0.495 EF4 to -1275 from -1260. Plasma into rampdown ---------------------------------------------------------------------------- 1000622003 irby PHYSICS_OPERATOR Jun 22 2000 9:44:41:046AM . . . . . . . . . . . . . . . . . . . . Still have positive BZ0: Gas not too bad. Changes for the Probe: Changed ZXL from -.014 to -.020 Added linear 2 mm outward shift to RCUR from 0.667 to 0.669 m. Load/Clean and go Plasma but lots of x-rays early Too much argon ---------------------------------------------------------------------------- 1000622004 irby PHYSICS_OPERATOR Jun 22 2000 10:09:24:170AM . . . . . . . . . . . . . . . . . . . . Dropped argon back from 60 to 20 ms Took prepuff from 70 to 75 volts at 34 ms in attempt to reduce early hards. Fizzle Looks like it's time to drop Bz0 ---------------------------------------------------------------------------- 1000622005 irby PHYSICS_OPERATOR Jun 22 2000 10:25:29:843AM . . . . . . . . . . . . . . . . . . . . Ef4 from -1275 to -1285 in attempt to reduce Bz0 Plasma into rampdown ---------------------------------------------------------------------------- 1000622006 irby PHYSICS_OPERATOR Jun 22 2000 10:55:13:530AM . . . . . . . . . . . . . . . . . . . . ************** c-side to all H2 ********************* Prefill (b-top) still D2 for startup Fizzle: breakdown late --- pressure looks low ---------------------------------------------------------------------------- 1000622007 irby PHYSICS_OPERATOR Jun 22 2000 11:14:28:640AM . . . . . . . . . . . . . . . . . . . . Fizzle ---------------------------------------------------------------------------- 1000622008 irby PHYSICS_OPERATOR Jun 22 2000 11:28:37:280AM . . . . . . . . . . . . . . . . . . . . Added 2ms to prefill. The pressure is too low, but the startup current rise indicates we have too much gas?? Fizzle! Pressure is up; drift on Br0 and Bz0 ---------------------------------------------------------------------------- 1000622009 irby PHYSICS_OPERATOR Jun 22 2000 11:47:25:810AM . . . . . . . . . . . . . . . . . . . . EF4 to -1295 from -1285. Set BR0 offset to 0.0000 from 0.0003 T Plasma into rampdown at last BZ0 up? BR0 down as expected ---------------------------------------------------------------------------- 1000622010 irby PHYSICS_OPERATOR Jun 22 2000 12:12:09:373PM . . . . . . . . . . . . . . . . . . . . Eliminated TF waggle until Amanda needs it again Increased Argon puff from 20 to 30 ms Plasma to rampdown H-to-D way up RGA indicates lower mass 4 and higher mass 2 over last couple of shots ---------------------------------------------------------------------------- 1000622011 irby PHYSICS_OPERATOR Jun 22 2000 12:32:55:046PM . . . . . . . . . . . . . . . . . . . . PCS Repeat Plasma into rampdown, but killed by a brick ---------------------------------------------------------------------------- 1000622012 irby PHYSICS_OPERATOR Jun 22 2000 12:59:52:826PM . . . . . . . . . . . . . . . . . . . . EF1U railed during last shot: put rampdown on Ip from 1e6 to .95e6 at 1.5 s. Reduced prefill by 1 ms: improve current rise? Plasma into rampdown but still pushing EF1s hard Ip rise better; pressure a little lower ---------------------------------------------------------------------------- 1000622013 irby PHYSICS_OPERATOR Jun 22 2000 1:18:17:390PM . . . . . . . . . . . . . . . . . . . . Dropped Ip flattop to 900kA Plasma into rampdown --- got about 850 kA, still railing EF1s ---------------------------------------------------------------------------- 1000622014 irby PHYSICS_OPERATOR Jun 22 2000 1:32:08:310PM . . . . . . . . . . . . . . . . . . . . No changes in PCS Plasma into rampdown ---------------------------------------------------------------------------- 1000622015 irby PHYSICS_OPERATOR Jun 22 2000 1:49:58:983PM . . . . . . . . . . . . . . . . . . . . Add 10 ms to argon for John: 40 ms total Plasma into rampdown ---------------------------------------------------------------------------- 1000622016 irby PHYSICS_OPERATOR Jun 22 2000 2:10:54:606PM . . . . . . . . . . . . . . . . . . . . Going to Ohmic H-Mode Part of Run Loaded segment 2 from 1000518007 Argon is just 30 ms again ********** camac errors ******************* took shot with breakers open ---------------------------------------------------------------------------- 1000622017 irby PHYSICS_OPERATOR Jun 22 2000 2:46:02:373PM . . . . . . . . . . . . . . . . . . . . Plasma to 0.667 s Looks like gaps are too large ---------------------------------------------------------------------------- 1000622018 irby PHYSICS_OPERATOR Jun 22 2000 3:02:05:530PM . . . . . . . . . . . . . . . . . . . . RCUR to 0.671 from 0.666 m Plasma to 0.63 s ---------------------------------------------------------------------------- 1000622019 irby PHYSICS_OPERATOR Jun 22 2000 3:23:49:826PM . . . . . . . . . . . . . . . . . . . . Because we can't find another knob we are disabling the Argon for this shot Added 1ms to prefill --- Good Plasma, but didn't make Ip request Still low pressure and very fast current rise ---------------------------------------------------------------------------- 1000622020 irby PHYSICS_OPERATOR Jun 22 2000 3:38:37:623PM . . . . . . . . . . . . . . . . . . . . Bt now kept at 3 T until rampdown Raised prop gain on Ip to 7 from 6 Plasma to 1.4 s --- Steve mentions that not brings the TF back up was the problem as found in earlier runs ---------------------------------------------------------------------------- 1000622021 irby PHYSICS_OPERATOR Jun 22 2000 4:00:52:106PM . . . . . . . . . . . . . . . . . . . . Dropped Bt by 10% (74000 to 67000 Amps) but raised it up again starting at 1.3 s to keep from disrupting Plasma to 1.266 s --- h-mode ---------------------------------------------------------------------------- 1000622022 irby PHYSICS_OPERATOR Jun 22 2000 4:17:36:280PM . . . . . . . . . . . . . . . . . . . . Repeat PCS Plasma for 1.2 s ---------------------------------------------------------------------------- 1000622023 irby PHYSICS_OPERATOR Jun 22 2000 4:32:20:683PM . . . . . . . . . . . . . . . . . . . . Dropped field another 10% (60kA) Plasma for 1.16 s --- short h-mode ---------------------------------------------------------------------------- 1000622024 irby PHYSICS_OPERATOR Jun 22 2000 4:46:14:343PM . . . . . . . . . . . . . . . . . . . . RCUR reduced by 2 mm to get plasma away from limiter Plasma to about 1.1 s Gap is bigger but still had large injection ---------------------------------------------------------------------------- 1000622025 irby PHYSICS_OPERATOR Jun 22 2000 5:20:57:060PM . . . . . . . . . . . . . . . . . . . . Repeat Plasma ---------------------------------------------------------------------------- 1000622026 irby PHYSICS_OPERATOR Jun 22 2000 5:21:44:310PM . . . . . . . . . . . . . . . . . . . . Gas test only ---- no plasma |
| Session Leader Comments | |||
| Jun 22 2000 08:54:00:640AM | Martin Greenwald | MP 274 H/D Changeover Quantify the interaction between the plasma and wall hydrogen/deuterium inventories. Background: AT operation on C-Mod will require lower densities than our standard H-modes. To achieve this, we will require some form of active particle control (for example, a cryopump). This active control must compete quantitatively with the pumping and outgassing of the walls. Thus, it is important that we have a measure of the effective particle inventory contained by the walls and the rate at which this inventory is exchanged during normal operation. While the walls potentially hold an inventory which is 2 orders of magnitude larger than that in the plasma, past experience suggests that only a small fraction of the total wall inventory is involved in this exchange. Factors effecting the interaction between gas in the wall and the plasma include the area "wetted" by the plasma, depth of particle depostion in the wall, and the nature of the binding between the wall and the neutral molecules. Approach: Start with a standard shot. Change all filling and puffed gasses from D$_2$ to H$_2$ while running constant discharges. Look for H/D ratio in plasma, residual gas, etc. When the plasma is measured to be 90-95\% hydrogen, reverse the process by switching the gas back to D$_2$. If time permits, repeat the experiment once the H levels fall to the 5-10\% level. | |
| Jun 22 2000 09:01:06:123AM | 1000622001 | Martin Greenwald | dud |
| Jun 22 2000 01:13:21:230PM | 1000622002 | Martin Greenwald | Good Shot - all D2 puff nebar ~ 2.0e20 H/(H+D) ~ .025 D/(H+D) ~ .975 H/D ratios logged here are based on Earl's normal analysis. We may have a problem for H >> D. |
| Jun 22 2000 09:43:08:403AM | 1000622003 | Martin Greenwald | Lots of xrays early, disrupts at 1.6 sec - all D2 puff nebar ~ 2.0e20 H/(H+D) ~ .025 D/(H+D) ~ .975 |
| Jun 22 2000 10:08:56:500AM | 1000622004 | Martin Greenwald | fizzle |
| Jun 22 2000 10:25:41:763AM | 1000622005 | Martin Greenwald | Good Shot - all D2 puff nebar ~ 2.1e20 H/(H+D) ~ .025 D/(H+D) ~ .975 |
| Jun 22 2000 10:50:37:467AM | 1000622006 | Martin Greenwald | fizzle |
| Jun 22 2000 11:07:31:607AM | 1000622007 | Martin Greenwald | fizzle |
| Jun 22 2000 11:22:36:780AM | 1000622008 | Martin Greenwald | fizzle |
| Jun 22 2000 12:20:48:937PM | 1000622009 | Martin Greenwald | Good Shot - D2 fill, ->First with H2 puff nebar ~ 2.1e20 H/(H+D) ~ .33 D/(H+D) ~ .67 tauH = 3.0 sec |
| Jun 22 2000 12:20:29:797PM | 1000622010 | Martin Greenwald | Good Shot - D2 fill, H2 puff nebar ~ 2.1e20 H/(H+D) ~ .47 D/(H+D) ~ .53 tauH = 4.3 sec |
| Jun 22 2000 12:40:01:077PM | 1000622011 | Martin Greenwald | Good Shot - D2 fill, H2 puff nebar ~ 2.1e20 H/(H+D) ~ .55 D/(H+D) ~ .45 tauH = 5.2 sec tauD = 4.2 sec |
| Jun 22 2000 12:58:25:577PM | 1000622012 | Martin Greenwald | Good Shot - D2 fill, H2 puff nebar ~ 2.1e20 H/(H+D) ~ .63 D/(H+D) ~ .37 |
| Jun 22 2000 01:15:14:950PM | 1000622013 | Martin Greenwald | Good Shot - D2 fill, H2 puff nebar ~ 2.1e20 H/(H+D) ~ .68 D/(H+D) ~ .32 |
| Jun 22 2000 01:38:00:500PM | 1000622014 | Martin Greenwald | Good Shot - D2 fill, H2 puff nebar ~ 2.1e20 H/(H+D) ~ .72 D/(H+D) ~ .28 |
| Jun 22 2000 02:06:50:297PM | 1000622015 | Martin Greenwald | Good Shot - D2 fill, H2 puff nebar ~ e20 H/(H+D) ~ .74 D/(H+D) ~ .26 Small (10-20%) errors may be creeping into H/D calculation This needs to be checked |
| Jun 22 2000 02:09:42:200PM | 1000622016 | Martin Greenwald | No shot - just daq cycle with errors |
| Jun 22 2000 04:15:12:483PM | 1000622017 | Martin Greenwald | First try at Ohmic H-mode - ramp down B field Early Disruption |
| Jun 22 2000 02:54:31:327PM | 1000622018 | Martin Greenwald | Disrupts early |
| Jun 22 2000 03:19:26:343PM | 1000622019 | Martin Greenwald | Shot OK but no H-mode Some signs of dithering at .6 and 1. sec |
| Jun 22 2000 04:14:29:450PM | 1000622020 | Martin Greenwald | Drop minimum B field by 10% Ohmic H-mode maybe marginally EDA H/(H+D) ~ .6 D/(H+D) ~ .4 |
| Jun 22 2000 04:08:28:340PM | 1000622021 | Martin Greenwald | Ohmic H-mode Clear EDA fluctuations on Reflectometer and PCI H/(H+D) ~ .6 D/(H+D) ~ .4 |
| Jun 22 2000 04:18:57:997PM | 1000622022 | Martin Greenwald | Ohmic H-mode EDA as seen by Refl, PCI frequency of quasi-coherent mode drops to 50kHz, same k H/(H+D) ~ .6 D/(H+D) ~ .4 |
| Jun 22 2000 04:36:19:827PM | 1000622023 | Martin Greenwald | Ohmic H-mode - EDA again q95 at 2.6 quasi-coherent mode seen on probes as well H/(H+D) ~ .6 D/(H+D) ~ .4 |
| Jun 22 2000 04:48:30:077PM | 1000622024 | Martin Greenwald | Very brief H-mode before impurity injection kills plasma H/(H+D) ~ .6 D/(H+D) ~ .4 |
| Jun 22 2000 05:34:46:357PM | 1000622025 | Martin Greenwald | H-mode lasted longer Dithering to EDA H/(H+D) ~ .6 D/(H+D) ~ .4 |
| Physics Operator Comments | |||
| Jun 22 2000 08:10:24:437AM | Jim Irby | Yesterday we had a leak on f-hor during most of the run. It was purged with argon after the run and the missing heaters re-installed. We ran overnight ECDC in D2 until about 07:00. This morning Tommy switched the purge back to pump and the mass 28 is back down to an acceptable level (7e-9). Did load/clean with no changes yet from last shot from yesterday Did coldstart: rtnode -- data loaded, A matrix responds rtnode -- data loaded, M matrix responds rtnode -- data loaded, PID matrix responds RT_NODE Done Startup from yesterday: shot: 1000621020 Time (ms): 0 5 10 25 ---------------------------------------- % Compiled module: DERIV. Ip (kA): -0.4015 -10.7782 -23.7489 -98.9796 dIp/dt (kA/ms): -1.1445 -2.4150 -3.6900 -6.6148 pressure (mTorr): 0.0442 0.0447 0.0442 0.0409 Bz0 (mT): -2.0981 -0.5061 1.7843 18.0441 Br0 (mT): -0.1454 -0.3747 -0.4058 -0.9838 Gas pretty low, but assume it will be a little higher on the first shot. | |
| Jun 22 2000 08:45:34:343AM | Jim Irby | Loaded from 1000616001 load/clean Note that the ef4 settings yesterday was -1295 vs -1260 for 6/16. So we may have a Bzo problem on the first shot. Prefill was from -0.52 to -0.50 in both cases. | |
| Jun 22 2000 09:05:56:280AM | 1000622001 | Jim Irby | Base pressure: 3.1e-7 Torr with GV3 closed. Dud Gas too low: Time (ms): 0 5 10 25 ---------------------------------------- Ip (kA): -0.4015 -5.5898 -10.8236 -10.8236 dIp/dt (kA/ms): -0.5065 -1.2739 -0.5098 -0.1294 pressure (mTorr): 0.0382 0.0386 0.0386 0.0391 Bz0 (mT): -1.5581 0.9187 1.7177 16.7000 Br0 (mT): -0.0466 -0.4153 -0.5299 -1.0321 |
| Jun 22 2000 09:21:29:250AM | 1000622002 | Jim Irby | Added 5 ms to prefill: -0.52 to -0.495 EF4 to -1275 from -1260. Plasma into rampdown |
| Jun 22 2000 09:44:41:047AM | 1000622003 | Jim Irby | Still have positive BZ0: Time (ms): 0 5 10 25 ---------------------------------------- Ip (kA): -0.4015 -5.5898 -18.5606 -99.0023 dIp/dt (kA/ms): -0.6358 -2.0368 -3.3063 -6.2322 pressure (mTorr): 0.0495 0.0495 0.0495 0.0468 Bz0 (mT): -0.7677 1.2110 3.2653 19.6667 Br0 (mT): -0.0794 -0.4403 -0.5534 -1.5298 Gas not too bad. Changes for the Probe: Changed ZXL from -.014 to -.020 Added linear 2 mm outward shift to RCUR from 0.667 to 0.669 m. Load/Clean and go Plasma but lots of x-rays early Too much argon |
| Jun 22 2000 10:09:24:170AM | 1000622004 | Jim Irby | Dropped argon back from 60 to 20 ms Took prepuff from 70 to 75 volts at 34 ms in attempt to reduce early hards. Fizzle Time (ms): 0 5 10 25 ---------------------------------------- Ip (kA): -0.4242 -13.3950 -26.3431 -21.1775 dIp/dt (kA/ms): -1.6542 -2.6682 -1.9074 1.3988 pressure (mTorr): 0.0523 0.0529 0.0529 0.0506 Bz0 (mT): -1.1239 1.3336 2.2078 17.2380 Br0 (mT): 0.2273 -0.4558 -0.3638 -1.0236 Looks like it's time to drop Bz0 |
| Jun 22 2000 10:25:29:843AM | 1000622005 | Jim Irby | Ef4 from -1275 to -1285 in attempt to reduce Bz0 Plasma into rampdown |
| Jun 22 2000 10:55:13:530AM | 1000622006 | Jim Irby | ************** c-side to all H2 ********************* Prefill (b-top) still D2 for startup Fizzle: breakdown late --- pressure looks low Time (ms): 0 5 10 25 ---------------------------------------- Ip (kA): -0.4242 -15.9892 -28.9600 -23.7944 dIp/dt (kA/ms): -1.6553 -2.9259 -2.2890 1.1467 pressure (mTorr): 0.0437 0.0452 0.0442 0.0413 Bz0 (mT): -2.2504 -0.1775 1.3576 16.2552 Br0 (mT): 0.3969 0.0284 -0.0742 -1.0941 |
| Jun 22 2000 11:14:28:640AM | 1000622007 | Jim Irby | Fizzle Time (ms): 0 5 10 25 ---------------------------------------- Ip (kA): 2.1926 -13.3723 -23.7717 -26.3885 dIp/dt (kA/ms): -1.3977 -2.7999 -2.9259 1.2694 pressure (mTorr): 0.0478 0.0473 0.0473 0.0437 Bz0 (mT): -1.1036 0.9205 2.3466 17.9132 Br0 (mT): 0.4868 -0.1492 -0.4534 -1.5373 |
| Jun 22 2000 11:28:37:280AM | 1000622008 | Jim Irby | Added 2ms to prefill. The pressure is too low, but the startup current rise indicates we have too much gas?? Fizzle! Time (ms): 0 5 10 25 ---------------------------------------- Ip (kA): -3.0184 -10.7782 -28.9373 -23.7717 dIp/dt (kA/ms): -1.1456 -2.6694 -3.3063 1.5271 pressure (mTorr): 0.0523 0.0518 0.0500 0.0457 Bz0 (mT): -1.4279 0.6137 2.1628 16.7914 Br0 (mT): 0.2827 0.2984 -0.0015 -1.2214 Pressure is up; drift on Br0 and Bz0 |
| Jun 22 2000 11:47:25:810AM | 1000622009 | Jim Irby | EF4 to -1295 from -1285. Set BR0 offset to 0.0000 from 0.0003 T Plasma into rampdown at last Time (ms): 0 5 10 25 ---------------------------------------- Ip (kA): -0.4242 -10.7782 -26.3431 -104.1906 dIp/dt (kA/ms): -1.4011 -2.7954 -4.0704 -7.3756 pressure (mTorr): 0.0512 0.0512 0.0500 0.0457 Bz0 (mT): -1.3165 0.6976 2.5878 18.9428 Br0 (mT): -0.1068 -0.2898 -0.7648 -1.6125 BZ0 up? BR0 down as expected |
| Jun 22 2000 12:12:09:373PM | 1000622010 | Jim Irby | Eliminated TF waggle until Amanda needs it again Increased Argon puff from 20 to 30 ms Plasma to rampdown H-to-D way up RGA indicates lower mass 4 and higher mass 2 over last couple of shots Time (ms): 0 5 10 25 ---------------------------------------- Ip (kA): 2.1926 -13.3950 -26.3658 -91.2425 dIp/dt (kA/ms): -1.2750 -2.9259 -3.0508 -5.9778 pressure (mTorr): 0.0548 0.0535 0.0529 0.0512 Bz0 (mT): -2.1167 0.2438 2.1892 17.9799 Br0 (mT): 0.1198 -0.6838 -0.3232 -2.0579 |
| Jun 22 2000 12:32:55:047PM | 1000622011 | Jim Irby | PCS Repeat Plasma into rampdown, but killed by a brick Time (ms): 0 5 10 25 ---------------------------------------- Ip (kA): -0.4242 -13.3723 -28.9373 -86.0315 dIp/dt (kA/ms): -1.5271 -2.7954 -2.7976 -5.2127 pressure (mTorr): 0.0535 0.0529 0.0541 0.0529 Bz0 (mT): -1.6365 -0.4165 1.9764 18.3525 Br0 (mT): -0.2325 -0.5248 -0.4092 -1.8047 |
| Jun 22 2000 12:59:52:827PM | 1000622012 | Jim Irby | EF1U railed during last shot: put rampdown on Ip from 1e6 to .95e6 at 1.5 s. Reduced prefill by 1 ms: improve current rise? Plasma into rampdown but still pushing EF1s hard Time (ms): 0 5 10 25 ---------------------------------------- Ip (kA): -0.4015 -13.3723 -28.9373 -93.7912 dIp/dt (kA/ms): -1.5282 -2.7965 -3.0508 -5.5964 pressure (mTorr): 0.0523 0.0523 0.0529 0.0512 Bz0 (mT): -1.9873 0.2729 2.7293 18.7218 Br0 (mT): -0.3746 -0.7339 -0.6122 -1.7256 Ip rise better; pressure a little lower |
| Jun 22 2000 01:18:17:390PM | 1000622013 | Jim Irby | Dropped Ip flattop to 900kA Plasma into rampdown --- got about 850 kA, still railing EF1s Time (ms): 0 5 10 25 ---------------------------------------- Ip (kA): -0.4015 -13.3723 -28.9373 -93.8139 dIp/dt (kA/ms): -1.3977 -3.0530 -3.0542 -5.7246 pressure (mTorr): 0.0484 0.0489 0.0489 0.0489 Bz0 (mT): -1.2369 -0.0364 1.3211 18.2188 Br0 (mT): -0.3406 -0.7042 -0.4551 -2.0822 |
| Jun 22 2000 01:32:08:310PM | 1000622014 | Jim Irby | No changes in PCS Plasma into rampdown Time (ms): 0 5 10 25 ---------------------------------------- Ip (kA): -0.4242 -13.3723 -31.5314 -96.3854 dIp/dt (kA/ms): -1.3999 -3.0508 -3.1813 -5.7224 pressure (mTorr): 0.0489 0.0495 0.0478 0.0500 Bz0 (mT): -1.7304 -0.0691 1.3392 18.4097 Br0 (mT): -0.3187 -0.8704 -0.9897 -1.6950 |
| Jun 22 2000 01:49:58:983PM | 1000622015 | Jim Irby | Add 10 ms to argon for John: 40 ms total Plasma into rampdown Time (ms): 0 5 10 25 ---------------------------------------- Ip (kA): 2.1926 -15.9438 -28.9373 -91.1971 dIp/dt (kA/ms): -1.6509 -3.1803 -2.9270 -5.7235 pressure (mTorr): 0.0484 0.0489 0.0484 0.0495 Bz0 (mT): -2.3994 0.4032 1.7648 18.3356 Br0 (mT): 0.3023 0.0234 -0.0671 -1.7665 |
| Jun 22 2000 02:10:54:607PM | 1000622016 | Jim Irby | Going to Ohmic H-Mode Part of Run Loaded segment 2 from 1000518007 Argon is just 30 ms again ********** camac errors ******************* took shot with breakers open |
| Jun 22 2000 02:46:02:373PM | 1000622017 | Jim Irby | Plasma to 0.667 s Time (ms): 0 5 10 25 ---------------------------------------- Ip (kA): -0.4015 -13.3723 -26.3431 -93.8367 dIp/dt (kA/ms): -1.5260 -2.7987 -2.7976 -5.5953 pressure (mTorr): 0.0495 0.0512 0.0495 0.0512 Bz0 (mT): -1.9871 -0.4901 1.6413 17.5836 Br0 (mT): -0.2004 -0.3711 -0.4052 -1.9212 Looks like gaps are too large |
| Jun 22 2000 03:02:05:530PM | 1000622018 | Jim Irby | RCUR to 0.671 from 0.666 m Plasma to 0.63 s Time (ms): 0 5 10 25 ---------------------------------------- Ip (kA): 2.1926 -13.3723 -28.9373 -109.3789 dIp/dt (kA/ms): -1.1445 -3.0531 -4.1976 -6.7408 pressure (mTorr): 0.0473 0.0473 0.0463 0.0447 Bz0 (mT): -1.5574 -0.0363 1.9614 17.6221 Br0 (mT): 0.3650 -0.2289 -0.9143 -1.7720 |
| Jun 22 2000 03:23:49:827PM | 1000622019 | Jim Irby | Because we can't find another knob we are disabling the Argon for this shot Added 1ms to prefill --- Good Plasma, but didn't make Ip request Time (ms): 0 5 10 25 ---------------------------------------- Ip (kA): 2.1926 -10.7782 -26.3658 -111.9731 dIp/dt (kA/ms): -1.1445 -3.0531 -4.4519 -6.6148 pressure (mTorr): 0.0489 0.0484 0.0489 0.0457 Bz0 (mT): -1.8936 -0.2898 2.4313 19.3600 Br0 (mT): -0.0674 -0.5486 -0.6789 -1.9987 Still low pressure and very fast current rise |
| Jun 22 2000 03:38:37:623PM | 1000622020 | Jim Irby | Bt now kept at 3 T until rampdown Raised prop gain on Ip to 7 from 6 Plasma to 1.4 s --- Steve mentions that not brings the TF back up was the problem as found in earlier runs Time (ms): 0 5 10 25 ---------------------------------------- Ip (kA): 2.2154 -13.3723 -26.3431 -111.9503 dIp/dt (kA/ms): -1.2728 -2.9259 -4.4507 -7.6299 pressure (mTorr): 0.0495 0.0512 0.0500 0.0463 Bz0 (mT): -3.0260 -0.4272 1.4776 19.0170 Br0 (mT): 0.3228 -0.4050 -0.7325 -2.2498 |
| Jun 22 2000 04:00:52:107PM | 1000622021 | Jim Irby | Dropped Bt by 10% (74000 to 67000 Amps) but raised it up again starting at 1.3 s to keep from disrupting Plasma to 1.266 s --- h-mode Time (ms): 0 5 10 25 ---------------------------------------- Ip (kA): 2.1699 -13.3950 -26.3431 -111.9731 dIp/dt (kA/ms): -1.3999 -2.6682 -4.3236 -6.8669 pressure (mTorr): 0.0506 0.0495 0.0506 0.0468 Bz0 (mT): -2.9442 0.0078 1.3489 18.9076 Br0 (mT): -0.2697 -0.3965 -0.3148 -1.9156 |
| Jun 22 2000 04:17:36:280PM | 1000622022 | Jim Irby | Repeat PCS Plasma for 1.2 s |
| Jun 22 2000 04:32:20:683PM | 1000622023 | Jim Irby | Dropped field another 10% (60kA) Plasma for 1.16 s --- short h-mode Time (ms): 0 5 10 25 ---------------------------------------- Ip (kA): 2.2154 -13.3496 -28.9373 -114.5672 dIp/dt (kA/ms): -1.2706 -3.1813 -4.4518 -7.2506 pressure (mTorr): 0.0560 0.0554 0.0566 0.0529 Bz0 (mT): -1.3564 -0.2535 1.7921 18.1606 Br0 (mT): -0.0257 -0.1564 -1.3365 -1.7483 |
| Jun 22 2000 04:46:14:343PM | 1000622024 | Jim Irby | RCUR reduced by 2 mm to get plasma away from limiter Plasma to about 1.1 s Gap is bigger but still had large injection Time (ms): 0 5 10 25 ---------------------------------------- Ip (kA): -0.3788 -13.3723 -28.9373 -109.3789 dIp/dt (kA/ms): -1.5282 -2.9248 -3.9421 -6.8658 pressure (mTorr): 0.0541 0.0541 0.0548 0.0500 Bz0 (mT): -2.2448 -0.5861 1.8554 18.6381 Br0 (mT): -0.2943 -0.4070 -0.3503 -1.8041 |
| Jun 22 2000 05:20:57:060PM | 1000622025 | Jim Irby | Repeat Plasma |
| Jun 22 2000 05:21:44:310PM | 1000622026 | Jim Irby | Gas test only ---- no plasma |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 08:57:28:327AM | Plasma | Ok | |
| 2 | 09:13:00:827AM | Plasma | Ok | |
| 3 | 09:32:50:513AM | Plasma | Ok | |
| 4 | 10:01:41:967AM | Plasma | Ok | |
| 5 | 10:16:30:857AM | Plasma | Ok | |
| 6 | 10:48:44:170AM | Plasma | Ok | |
| 7 | 11:05:26:090AM | Plasma | Ok | |
| 8 | 11:21:07:983AM | Plasma | Ok | |
| 9 | 11:41:32:637AM | Plasma | Ok | |
| 10 | 12:03:52:263PM | Plasma | Ok | |
| 11 | 12:24:13:937PM | Plasma | Ok | |
| 12 | 12:45:50:750PM | Plasma | Ok | |
| 13 | 01:06:10:653PM | Plasma | Ok | |
| 14 | 01:25:43:577PM | Plasma | Ok | |
| 15 | 01:43:54:750PM | Plasma | Ok | |
| 16 | 02:05:48:827PM | Plasma | Ok | |
| 17 | 02:23:47:530PM | Plasma | Ok | |
| 18 | 02:48:34:843PM | Plasma | Ok | |
| 19 | 03:13:22:357PM | Plasma | Ok | |
| 20 | 03:30:57:297PM | Plasma | Ok | |
| 21 | 03:52:10:060PM | Plasma | Ok | |
| 22 | 04:07:30:140PM | Plasma | Ok | |
| 23 | 04:23:09:653PM | Plasma | Ok | |
| 24 | 04:40:00:937PM | Plasma | Ok | |
| 25 | 04:56:07:827PM | Plasma | Ok | |
| 26 | 05:08:36:387PM | Test | Ok | Gas Test |