| Miniproposals | ||||||||||
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| Operators | |
| Session leader(s): | John Degrassie |
| Physics operator(s): | Ron Parker,Steve Wolfe,Ron Parker |
| Engineering operator(s): | Bill Parkin,Bill Byford |
| Engineering Operator Run Comment |
| MP #425 S/L J.S. deGrassie, Rice, P/O , E/O Pierson |
| Session Leader Plans |
| Entered: Aug 21 2007 04:29:49:290PM |
| Author: John Degrassie |
| RUN PLAN for 1070822
MP425 â??Toroidal rotation in dimensionally similar discharges with no momentum inputâ?? SL: J.S. deGrassie, J.E. Rice The goal is to run C-Mod discharges with dimensionless similarity to discharges in DIII-D, and measure the toroidal rotation velocity. Ultimately the goal is to discover a dimensionless scaling for intrinsic toroidal rotation, if such a description exists. To this end we will attempt some variations in one of the dimensionless parameters, and test for any effect due to rf deposition location. We are focused upon ELMing H-mode discharges. The target values for density and temperature are selected to achieve the desired normalized beta*, nu* and rho*. Presumably the two knobs are target density and rf power. SETUP: **Shape to be that used in 1050727028. **Diagnostic Systems / Operational Systems â?? defer to John Rice **ICRF â?? power to be varied as needed to achieve desired temperature, density. SHOT SEQUENCE: 1. BT = 5.75 T q95 = 4.75 (Ip ~ 925 KA ?) (match DIII-D 129525) a.) In 1050727028 the rf power was applied at t = 0.7sec with an H-mode transition following closely. This may need to be delayed a little at this higher Ip ? The goal is ne(core) = 2.3x10^20 and T(core) = 3.1 keV b.) Increase collisionality at same beta*. The goal is ne(core) = 3.1x10^20 and T(core) = 2.4 keV c.) Optional â?? even greater collisionality if above n and T were possible. ne(core) = 3.7x10^20 and T(core) = 2.0 keV 2. Increase q95 to 7.25 (Ip ~ 600 KA ?), with same beta*; collisionality as 1b. ne(core) = 2.7x10^20 T(core) = 2.7 keV 3. Decrease q95 to 3.5 (Ip ~ 1.25 MA ?), with same beta*; collisionality as 1b. ne(core) = 3.5x10^20 T(core) = 2.1 keV. 4. BT = 4.90 T q95 = 4.75 Modify rf deposition location with similar parameters. Target same beta* and nu* as 1b above, rho* very close. ne(core) = 2.5x10^20 T(core) = 2.1 keV. 5. Ohmic H-mode. First, try for the full 4 parameter match to a DIII-D OH H-mode (117657). If this is not achievable, try reducing BT (and Ip) and allow rho* to vary slightly. a.) BT = 5.23 T q95 = 3.2 Full match. ne(core) = 5.1x10^20 T(core) = 1.15 keV. b.) BT = 4.60 T q95 = 3.2 (if needed) ne(core) = 4.3x10^20 T(core) = 1.05 keV. c.) BT = 4.0 T q95 = 3.2 (if needed) ne(core) = 3.6x10^20 T(core) = 0.95 keV. |
| Physics Operators Plans |
| Session Leader Summaries |
| Entered: Aug 26 2007 07:36:20:163PM |
| Author: John Degrassie |
| Summary for 1070822
Of the run plan we achieved case 1a, a match to DIII-D shot 129125 achieved case 1b, a higher collisionality case for 1a achieved case 3, a lower q95 related case for 1a and achieved case 4, a lower BT case to provide a different (inboard) rf deposition. The other cases proved tough to land on, especially the tries at an Ohmic H-mode. I can see that we should find existing Ohmic H-mode cases on C-Mod and see if they can be matched in DIII-D. Today�??s data for the shots that were somewhere in orbit around the target values will also be very useful as we look at the results in terms of the dimensionless similarity parameters. To be specific on the matches above: 1a: 004, 003, 005 today 1b: 006 the machine just wanted to run at the desired parameters 1c: Was to have been a higher density version of 1b but we began having rf coupling problems and perhaps the necessary density is too high for this Ip. 2: Was to have been a lower Ip version of 1a. We could not get the necessary beta with the rf coupling. 3: 013 (lost some rotation data) 017 4: 019 020 We also got a very nice shot on 018 in attempting condition 4, but BT was not reduced to the necessary value. However, the data will be valuable. 5: These were tries for Ohmic H-mode at q95 = 3.2 We failed. However, even these high power Ohmic cases will be interesting to look at. |
| Physics Operator Summaries |
| Entered: Aug 22 2007 05:50:03:217PM |
| Author: Ron Parker |
| Machine ran well today, and much of the MP was accomplished although Ohmic H-Modes did not materialize. The shots spanned fields ranging from 4.6 to 5.75 T, with q varying from 3.2 to 7.25. The only machine problem was a failure of the vessel heater PLC, which caused the vessel temperature to drop to ~ -30 C. The heaters performed correctly after cycling the PLC and the vessel eventually recovered to ~ 0 C.
Scorecard: 27 attempts at plasma, 2 disruptions, 3 fizzles following the disruptions and 22 full length shots. |
| Session Leader Comments | |||
| Aug 22 2007 09:29:15:520AM | 1070822001 | John Degrassie | Goal: 1st condition on the run plan.
First shot: q95 a little too low. Large beta oscillations - Prf? |
| Aug 22 2007 09:32:54:807AM | 1070822001 | John Degrassie | Goal: first condition on plan
First shot ran well. q95 a little too low, ne0 and te0 are encouraging. |
| Aug 22 2007 09:43:11:790AM | 1070822002 | John Degrassie | Second try at first condition (1a)
Shot: in and out of H-mode |
| Aug 22 2007 09:56:10:983AM | 1070822003 | John Degrassie | Third try at first condition (1a)
Shot: Good shot until impurity injection killed at ~ 1.0 sec. The core beta* and nu* are very near the target values @ ~ 0.8 sec. |
| Aug 22 2007 10:32:23:883AM | 1070822004 | John Degrassie | Still on condition 1a.
Shot: Swings in and out of H-mode. Partial rotation spectrometer coverage throughtout the shot. ne0 and Te0 are dancing around the desired values with the cycles in stored energy. |
| Aug 22 2007 10:49:56:613AM | 1070822005 | John Degrassie | O.K. Condition 1a achieved with rotation data obtained.
Still swinging in and out of H-mode in this shot. |
| Aug 22 2007 11:15:09:683AM | 1070822006 | John Degrassie | Move on to condition 1b, higher collisionality at the same beta.
Shot: Looks like a good match! John says nice EDA H-mode. Move on. |
| Aug 22 2007 11:30:06:753AM | 1070822007 | John Degrassie | Go for condition 1c: even more collisionality at same beta
Shot: Too much gas puff (to achieve higher target density) for RF => no RF power => Ohmic shot. |
| Aug 22 2007 11:43:20:820AM | 1070822008 | John Degrassie | Try for case 1c again.
Shot: Low Prf => L-mode. Gas still too high. |
| Aug 22 2007 12:03:34:757PM | 1070822009 | John Degrassie | Goal is condition 1c again
Shot: Prf much better, trippy, but H-mode. Density below target. Difficult to achieve as high a density as called for. Move on for now. |
| Aug 22 2007 12:19:39:017PM | 1070822010 | John Degrassie | Move on to condition 2
BT = 5.75 T q95 = 7.25 same beta and nu*q95 as 1b Shot: Not enough Prf to obtain H-mode. => L-mode shot. |
| Aug 22 2007 12:37:57:827PM | 1070822011 | John Degrassie | Goal is condition 2
Shot: q95 is on target. RF power trippy, but H-modes. Need more time averaged RF power to obtain desired beta. |
| Aug 22 2007 12:50:05:173PM | 1070822012 | John Degrassie | Goal: condition 2
Shot: Prf greater, but still trippy, H-mode with beta below target. |
| Aug 22 2007 01:06:51:323PM | 1070822013 | John Degrassie | Try for the low q95 condition, #3
q95 = 3.5, same beta as condition 1b, same nu*q95 as condition 1b. Shot: q95 very close. H-mode, RF power trippy, need more to raise beta. |
| Aug 22 2007 01:24:27:880PM | 1070822014 | John Degrassie | Goal: condition 3
Shot: Early disruption t ~ 0.75sec |
| Aug 22 2007 01:40:28:093PM | 1070822015 | John Degrassie | Goal: condition 3
Shot: fizzle |
| Aug 22 2007 01:47:05:550PM | 1070822016 | John Degrassie | Goal: condition 3
Shot: another fizzle |
| Aug 22 2007 02:05:44:030PM | 1070822017 | John Degrassie | Goal: condition 3
Shot: O.K. Prf still trippy, but (beta,nu) very close to the desired target at certain times in the shot; rotation data obtained. So we'll move on to the change of RF power deposition location. |
| Aug 22 2007 02:25:00:527PM | 1070822018 | John Degrassie | Move on to condition #4 to change the RF power deposition location with the dimensionless parameters the same as 1b (except for very small change in rho*)
BT= 4.9 T q95 = 4.75 beta and nu as in 1b. Shot: Very nice shot. EDA H-mode. But BT = 5.75 T still. q95 ~ 5.4 Ip ~ 740 KA Core beta is about 90% of 1b target and nu about twice the target of 1b. |
| Aug 22 2007 02:34:35:713PM | 1070822019 | John Degrassie | Goal: condition #4
Shot: Very nice. Core density is right on, Te just a little low. Good rf power coupling. Got rotation data. |
| Aug 22 2007 02:48:15:657PM | 1070822020 | John Degrassie | Goal: condition #4 Repeat with more RF power.
Shot: Very nice. even closer to desired (beta,nu) |
| Aug 22 2007 03:04:54:590PM | 1070822021 | John Degrassie | Go on to condition #5, the Ohmic H-mode. This would be a 4 dimensionless parameter match to an Ohmic H-mode in DIII-D (117657) with a measurement of the intrinsic rotation profile.
BT = 5.23 T q95 = 3.2 Shot: No Ohmic H-mode. Got q95=3.2 It looks like OH-H will be very tough at this high of a BT value. |
| Aug 22 2007 03:44:06:430PM | 1070822022 | John Degrassie | Try again for condition #5
Shot: fizzle |
| Aug 22 2007 04:16:09:197PM | 1070822023 | John Degrassie | Goal: condition #5 try again
Shot: Again, no OH-Hmode |
| Aug 22 2007 04:34:16:820PM | 1070822024 | John Degrassie | Go to relaxed condition #5 with small change in rho*
BT = 4.6 T q95 = 3.2 Shot: No OH-H, but BT was still at 5.23 T. |
| Aug 22 2007 04:46:56:277PM | 1070822025 | John Degrassie | Go to relaxed condition #5 with small change in rho*
BT = 4.6 T q95 = 3.2 Shot: Got BT = 4.6 q95 = 3.2, but no OH-H |
| Aug 22 2007 05:05:18:337PM | 1070822026 | John Degrassie | Trying for OH-Hmode Try to add an RF 'kick' to trigger the H-mode
Go back to BT = 5.23 T for rf deposition location. Shot: No OH H-mode. Only H-mode during rf pulse. |
| Aug 22 2007 05:18:07:670PM | 1070822027 | John Degrassie | Trying for OH-Hmode Try to add an RF 'kick' to trigger the H-mode
Use BT = 4.6 T Shot: Appears to be only RF H-mode again. Must look closely. |
| Physics Operator Comments | |||
| Aug 21 2007 05:29:19:693PM | Ron Parker | Engineering setup for Wednesday 22 Aug 2007
MP#425 Toroidal rotation in dimensionally similar discharges with no momentum input� Session leader: J. S. deGrassie, J. F. Rice Physics operator: R. Granetz Overnight ECDC Power systems as on 1070821003 A-coil configuration: +Dtop -Dbot -Jtop +Jbot; Enabled (standard configuration) 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 Enable the following gate valves and shutters, assuming no vacuum problems: ECE, VUV, DNB, Z-bolo shutters Torvac setup: gate valves open after the shot Specific diagnostics: edge and core Thomson, ECE diagnostics, CXRS, bolometer arrays, PCI, reflectometry, HIREX ------------------------------------------------------------------------------- ICRF Setup: all transmitters in run-on by 08:30. 3 MW flat from 0.5 to 1.5 s. LH Setup: no DNB: yes, ready for first shot. 50 kV, 6 A; 30 ms on/15 ms off Cryopump: no ------------------------------------------------------------------------------- Run Plan: See SL Plan. We'll start with a shape similar to 1050727028. | |
| Aug 22 2007 09:09:21:323AM | 1070822001 | Ron Parker | Good morning. First shot went off at 9:05. It was modeled after shot 1050727028.
Shot went off OK, "sawtoothing" H-Modes. A problem with Pat coming in late. |
| Aug 22 2007 09:28:57:817AM | 1070822002 | Ron Parker | For next shot, increase q by ~ 10%, lower density if possible and increase Argon puff to 70 ms. Also, extend TF and ramp it faster from 5.4 to 5.75 T. |
| Aug 22 2007 09:41:24:007AM | 1070822002 | Ron Parker | Shot 2 ran OK. Again, intermittent H-Modes.
q appears about right, but fine tune for next shot. |
| Aug 22 2007 09:54:21:277AM | 1070822003 | Ron Parker | HIREX needs some tests, so shot cycle will be held until these are done.
Cell access required to check HIREX trigger. |
| Aug 22 2007 09:57:21:750AM | 1070822003 | Ron Parker | Shot 3 looked good until about 1 s when it disrupted due to moly injection.
Next: repeat shot 3. Ooops, cell access cancelled. Trigger seems to be OK. |
| Aug 22 2007 10:09:00:033AM | 1070822003 | Ron Parker | Ooops, oops -- cell access required for HIREX after all. |
| Aug 22 2007 10:29:50:723AM | 1070822004 | Ron Parker | Shot 4 ran OK, intermittent H-modes. Next: repeat shot. |
| Aug 22 2007 10:40:38:333AM | 1070822005 | Ron Parker | Shot 5 ran OK, same intermittent H-modes. |
| Aug 22 2007 10:46:54:077AM | 1070822005 | Ron Parker | Next: Raise target density to 0.9e20 m-2 |
| Aug 22 2007 10:54:40:120AM | 1070822005 | Steve Wolfe | After shot 6 I will be taking over as physop from Ron for a couple hours |
| Aug 22 2007 11:07:03:593AM | 1070822006 | Steve Wolfe | Shot#6: There was a long delay before 6 for PLC program and there was also a cooling problem. plasma to 1.75sec, nebar in H-mode 2.9e20, 2.3keV, close enough for government work. |
| Aug 22 2007 11:29:51:847AM | 1070822007 | Steve Wolfe | Shot#7: raise nl04 target from 0.9e20 to 1.1e20, aiming for 20% increase in ne0 (h-mode) to 3.7e20 Delay because /usr/local/cmod/codes/ seems to be full! plasma full length, but no rf? Got E, no D or J (faulted out) neutral density is a little too high for rf, back off target density while cryo is cooling down |
| Aug 22 2007 11:45:11:480AM | 1070822008 | Steve Wolfe | Shot#8: drop target from 1.1 to 1.0e20 also, drop pg 4 from 20ms to 19ms just to be a little proactive on startup plasma, but still not enough rf. midplane pressure is still over 0.5mTorr rising to over .7mTorr when the RF comes on. Try starting rf earlier, turn NINJA off (not sure when it's coming in) |
| Aug 22 2007 12:00:45:613PM | 1070822009 | Steve Wolfe | Shot#9: Try starting rf earlier, turn NINJA off (not sure when it's coming in) cryopump beginning to pump during INIT, may lose startup. Data system problem in INIT, no actions; got started again after 2:30 pressure down to 5.5e-7Torr at Check. Plasma, looks like we got H-modes, so some RF must have worked. Density is still down around 3e20. John wants to go back to shot #6, lower current. Let NINJA turn back on. |
| Aug 22 2007 12:16:54:357PM | 1070822010 | Steve Wolfe | Shot#10: John wants to go back to shot #6, lower current. Let NINJA turn back on. Drop Ip to 560kA, aiming for q95=7.25 (step 2) Flatten CLEARIN waveform between 1.0 and 1.5sec (was rising from -.002 to .003 (why?), change 1.5sec point to 0.000 plasma, no h-mode. q95 is only 6.6, need to drop the current some more |
| Aug 22 2007 12:36:14:540PM | 1070822011 | Steve Wolfe | Shot#11: Decrease current to 500ka, nl04 from 9 to 8e19 plasma, a couple of h-modes, but not what we want yet, I think. q95~7.4, but ne0~2.1 and Te0~2.4. RF very ratty. RF doesn't like this target. Yijun will try to do better. Meanwhile, I'm going to put the gaps back where they were. |
| Aug 22 2007 12:37:47:230PM | 1070822011 | Steve Wolfe | Shot#11: Decrease current to 500ka, nl04 from 9 to 8e19 plasma, a couple of h-modes, but not what we want yet, I think. q95~7.4, but ne0~2.1 and Te0~2.4. RF very ratty. RF doesn't like this target. Yijun will try to do better. I was going to put the gap back to previous, but of course I did that when I re-imported from shot#6. Try putting nl04 back up to 0.9 |
| Aug 22 2007 12:47:29:793PM | 1070822012 | Steve Wolfe | Shot#12: Try putting nl04 back up to 0.9. Yijun will increase D, see what he can do with J and E. plasma, big marfe at .5sec RF still not happy Parker back as physop |
| Aug 22 2007 12:57:35:810PM | 1070822012 | Ron Parker | Shot 13 coming up, will increase current to 1.15 MA, q_95~3.5 |
| Aug 22 2007 01:07:57:280PM | 1070822013 | Ron Parker | Shot 13 ran OK, intermittent H-Modes. Try again, drop q by 3%. |
| Aug 22 2007 01:30:37:853PM | 1070822014 | Ron Parker | Shot 13 disrupted --try again. |
| Aug 22 2007 01:33:53:363PM | 1070822015 | Ron Parker | Shot 15 was the usual post-disruption fizzle. |
| Aug 22 2007 02:05:05:120PM | 1070822016 | Ron Parker | Shot 16 fizzled again, a healthier fizzle but nevertheless a fizzle.
|
| Aug 22 2007 02:04:07:230PM | 1070822017 | Ron Parker | OK, shot 17 ran, although H-Modes still sawteeth.
But we need to move on. |
| Aug 22 2007 02:22:29:930PM | 1070822018 | Ron Parker | Shot 18 was a nice steady H-Mode, but the wrong q, namely 5.5 vs. 4.75 due to operator error. Should be corrected on next shot. |
| Aug 22 2007 02:33:16:663PM | 1070822019 | Ron Parker | Not bad shot, steady H-mode. Try again, more RF power. |
| Aug 22 2007 02:53:23:900PM | 1070822020 | Ron Parker | Shot 20 was good. |
| Aug 22 2007 03:01:23:240PM | 1070822021 | Ron Parker | Shot 21 ran well, but no H-Mode.
Next: Drop density to 0.8 (from 1.0)and increase clearin by 3 mm, at suggestion of S. Wolfe. |
| Aug 22 2007 03:13:11:447PM | 1070822021 | Ron Parker |
Slight delay in the action to check vessel heaters. |
| Aug 22 2007 03:42:56:443PM | 1070822022 | Ron Parker | The obligatory post-disruption fizzle. It may take one more shot to clean..
|
| Aug 22 2007 04:05:06:883PM | 1070822022 | Ron Parker | Still waiting for heaters to restore temperature to vessel. Not clear why the vessel temperature is not regulating. |
| Aug 22 2007 04:26:11:260PM | 1070822023 | Ron Parker | Shot 23 went off well, no H-Mode.
Next: Try for 4.6 T Ohmic H-Mode, shot 5b on run plan. Heaters and Vessel temperature seem to be recovering -- PLC problem? |
| Aug 22 2007 05:00:01:453PM | 1070822024 | Ron Parker | Shot 24 ran well but field was not correct, 5.23 rather than 4.6 T |
| Aug 22 2007 05:08:42:670PM | 1070822025 | Ron Parker | Shot 25 ran well. |
| Aug 22 2007 05:00:50:313PM | 1070822026 | Ron Parker | Shot 26 ran OK. Short H-Mode when RF was on. |
| Aug 22 2007 05:21:00:440PM | 1070822027 | Ron Parker | Shot 27 ran, but disrupted at 1.18 s |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 09:03:11:790AM | Plasma | Ok | |
| 2 | 09:28:52:160AM | Plasma | Ok | |
| 3 | 09:41:37:053AM | Plasma | Ok | |
| 4 | 10:19:13:580AM | Plasma | Ok | |
| 5 | 10:37:47:720AM | Plasma | Ok | |
| 6 | 11:03:17:180AM | Plasma | Ok | |
| 7 | 11:23:08:993AM | Plasma | Ok | |
| 8 | 11:35:52:747AM | Plasma | Ok | |
| 9 | 11:55:05:963AM | Plasma | Ok | |
| 10 | 12:11:11:177PM | Plasma | Ok | |
| 11 | 12:27:55:030PM | Plasma | Ok | |
| 12 | 12:43:12:660PM | Plasma | Ok | |
| 13 | 12:59:48:233PM | Plasma | Ok | |
| 14 | 01:15:44:947PM | Plasma | Ok | |
| 15 | 01:31:32:573PM | Plasma | Ok | |
| 16 | 01:44:37:547PM | Plasma | Ok | |
| 17 | 01:57:21:923PM | Plasma | Ok | |
| 18 | 02:12:52:680PM | Plasma | Ok | |
| 19 | 02:26:46:297PM | Plasma | Ok | |
| 20 | 02:39:24:830PM | Plasma | Ok | |
| 21 | 02:53:12:510PM | Plasma | Ok | |
| 22 | 03:40:15:487PM | Plasma | Ok | |
| 23 | 04:09:41:983PM | Plasma | Ok | |
| 24 | 04:26:41:963PM | Plasma | Ok | |
| 25 | 04:39:42:360PM | Plasma | Ok | |
| 26 | 04:56:31:947PM | Plasma | Ok | |
| 27 | 05:08:59:420PM | Plasma | Ok | |
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