| Miniproposals | ||||||||||
|
| Operators | |
| Session leader(s): | Jerry Hughes |
| Physics operator(s): | Earl Marmar |
| Engineering operator(s): | Sam Pierson,Gary Dekow |
| Engineering Operator Run Comment |
| MP 410 Extension of pedestal scalings |
| Session Leader Plans |
| Entered: Aug 2 2005 05:07:21:410PM |
| Author: Earl Marmar |
| MP 410 Extension of pedestal scalings
SL: Jerry Hughes PO: Earl Marmar This run will collect edge profile data over a range of Bt, Ip, with RF power varied during each shot. J-port at 50MHz will be the predominate source of power, though 2nd harmonic heating from E-port (80MHz) may also be tried. *GPC/GPC2 should be optimized for ~4T *GPI camera should be configured to image background D-alpha. 1. Begin by loading 1050428027 (Bt=4.4 T, Ip=0.9MA, nl~0.9e20). J-port request: flat 1.0MW 0.60--0.80s flat 1.5MW 0.95-1.15s flat 2.0MW 1.30-1.50s ~2 shots. 2. Lower Bt to 3.5T. Run a series of shots with different Ip. J-port request: flat 1.5MW 0.80-1.00s flat 2.0MW 1.20-1.40s ~2 shots: 3.5T, 0.9MA (q95~2.8) nl=0.9e20 ~2 shots: 3.5T, 0.6MA (q95~4.2) nl=0.6e20 ~2 shots: 3.5T, 0.4MA (q95~6.3) nl=0.4e20 3. Lower Bt to 2.6T. Run a series of shots with different Ip. J-port request: flat 1.5MW 1.00-1.20s flat 2.0MW 1.35-1.55s ~2 shots: 2.6T, 0.4MA (q95~5.0) nl=0.4e20 ~2 shots: 2.6T, 0.6MA (q95~3.3) nl=0.6e20 ~2 shots: 2.6T, 0.8MA (q95~2.5) nl=0.8e20 4. Back to 3.5T. J-port request: flat 1.5MW 0.80-1.00s flat 2.0MW 1.20-1.40s ~2 shots: 3.5T, 0.8MA (q95~3.1) nl=0.8e20 ~2 shots: 3.5T, 1.0MA (q95~2.5) nl=1.0e20 5. Revisit above shots where more data are desired. ~12 shots SL reserves the right to play with these exact parameters and the ordering of shots. Essential diagnostics: Thomson, GPC, TCI, bolometry, PCI. Scanning probes, if available. Will use GPI camera to image background D-alpha, and will probably want to adjust gains on the Xybion camera on the fly. |
| Physics Operators Plans |
| Entered: Aug 2 2005 05:13:25:783PM |
| Author: Earl Marmar |
| Physop plan for Wednesday, August 3, 2005
MP 410 Extension of pedestal scalings SL: Jerry Hughes PO: Earl Marmar _________________________________________________ Overnight boronization use 120 psi from 10%B_2D_6/90%He bottle scan resonance from 50 to 103 cm, dwell at 52 normal fill pressures and duty factors follow boronization with: 4 hours He ECDC (5e-5 torr gauge) 1 hour D2 ECDC (2e-4 torr gauge) __________________________________________ Engineering setup as on 1050802001 A-coil configuration: normal [+Dtop -Dbot -Jtop +Jbot] and enabled. Gas Setup: fill B-Top with 6 psi D2 Hybrid enabled (PG4) fill B-side lower with 1 psi Ar, 2 psi neon (mixed in plenum) Hybrid disabled (PG1) leave B-side upper 15 psi He3, disabled (PG2) fill B-main with 40 psi D2 Hybrid enabled (PG3) Enable the following: NeSox, ECE and VUV gate valves, Z-bolo shutters ICRF Setup: transmitters in run-on at 8:30 __________________________ |
| Session Leader Summaries |
| Entered: Aug 3 2005 05:47:11:410PM |
| Author: Jerry Hughes |
| The purpose of this run was to collect edge profile data over a range of Bt and Ip, with RF power varied during each shot. J-port at 50MHz was the predominate source of power, though 2nd harmonic heating from E-port (80MHz) was also tried at the lowest fields. The run was quite successful in exploring the parameter space available at low magnetic field. The machine ran well, and multiple H-modes were obtained in a range of Bt from 2.6 to 4.4T, and a range of Ip from 0.4 to 1.0MA. Edge safety factor ranged from approximately 2.6 to 6.1 in the H-modes obtained. There were significant trips in J-port power on a number of the shots, especially those with high neutral pressure and/or low edge q. However ICRF power was sufficient to trigger H-modes, which were readily sustained at the low toroidal fields used in this experiment. A great number of the H-modes obtained were Ohmic, and many exhibited significant density peaking associated with ITB formation. Edge Thomson operated reliably and many data were obtained. Profiles will be fitted and stored in the database, along with data from the previous run days of this MP, for further analysis. Trends in pedestal parameters with Bt, Ip, and/or q_95 will be examined in both EDA and ELM-free regimes. Background D-alpha data were also obtained on a number of shots using the GPI camera, and may prove useful in performing a radial transport analysis. Thanks to everyone whose work made this run possible. |
| Physics Operator Summaries |
| Entered: Aug 4 2005 10:38:05:697AM |
| Author: Earl Marmar |
| This was a very good run. The machine ran well, and most of the
conditions called out in the miniproposal were visited. A-coil feedback was used, starting with shot 16, and seemed to work as expected. The only startup tweaks were to the prepuff fill, starting low (post-boronization) and creeping up through the day. The first shot fizzled, as did shot 19. Runaways continue to be a problem on some shots, not always correlating with startup hesitations. We had many shots today with q_95 at or below 3; they all disrupted at some point during flattop, but data were obtained for the MP on nearly all. There were some interesting shots from the point of view of neutron rate as a function of stored energy. Compared to our database of normal discharges, several today showed high fusion rates at relatively low stored energy. The best example is shot 34, where the neutron rate exceeds 1e13/s with a stored energy of only ~35 kJ. Typically, neutron rate at 35 kJ is about 1e11/s. The comparison between Wtot (EFIT) and 2*W(electron_thomson) showed excellent agreement. There are 2 known previous conditions on C-Mod which show "anomalous" neutron rates: PEP modes, which have very peaked density profiles, and a run from 1997 using RF at 40 MHz, B_T = 5 tesla, with high hydrogen fraction. For the latter, the logbook entry for 970606018 from Yuichi Takase (session leader that day) makes cryptic reference to "ion heating". For today's shots, the electron density profile in H-mode at the time of the peak neutron rate is very flat, so density peaking can't explain the result. I interpret today's results to mean that either there is a deuteron tail being produced or the ion temperature is much higher than the electron temperature. However, high ion temperature is probably not consistent with the agreement between Wtot and 2*W_electron. The conditions on shot 34 were B=3.5 tesla, I_p = 400 kA, nl_04 (h-mode) = 7.5e19, with J-port operating at 50 MHz, 2 MW. The plasma is deuterium majority, hydrogen minority, with no He-3 being puffed all day. At the time of peak neutron rate, Z_ave ~ 1.4. Scorecard: 2 fizzles 0 duds 34 plasmas 36 total data cycles |
| Session Leader Comments | |||
| Aug 3 2005 09:07:26:470AM | 1050803001 | Jerry Hughes | Attempt 4.4T, 0.9MA plasma.
Fizzle. Next shot: retry |
| Aug 3 2005 09:21:55:360AM | 1050803002 | Jerry Hughes | Attempt 4.4T, 0.9MA plasma.
Plasma is there, but I made a mistake in asking for J-port at 50MHz. Next shot: Retry with E-port, and actually put the resonance inside the plasma. |
| Aug 3 2005 09:40:18:877AM | 1050803003 | Jerry Hughes | Attempt 4.4T, 0.9MA plasma.
E-port peaks at about 1.3MW. Very little heating, though there are H-modes. Yijun says we're not getting more power out of E, so let's move on to lower field. Next shot: Lower Bt to 3.5T. Fire J-port. |
| Aug 3 2005 10:01:40:313AM | 1050803004 | Jerry Hughes | 3.5T, 0.9MA plasma.
3 Ohmic H-modes. Next shot: Repeat, try for some RF power. |
| Aug 3 2005 10:02:37:440AM | 1050803005 | Jerry Hughes | 3.5T, 0.9MA plasma.
2 H-modes with RF. Next shot: Ip-->0.6MA |
| Aug 3 2005 10:13:42:267AM | 1050803006 | Jerry Hughes | 3.5T, 0.6MA plasma.
2 H-modes. J-port steady at 1.5MW, less good at 2MW Next shot: Repeat |
| Aug 3 2005 10:26:10:780AM | 1050803007 | Jerry Hughes | 3.5T, 0.6MA plasma.
2 H-modes. Steadier power on J-port. Next shot: Ip-->0.4MA |
| Aug 3 2005 10:44:19:297AM | 1050803008 | Jerry Hughes | 3.5T, 0.4MA plasma.
2 good H-modes Next shot: Earl will extend flattop to 1.8s, and Yijun will put in a third RF pulse from 1.6 to 1.8. |
| Aug 3 2005 11:45:58:063AM | 1050803011 | Jerry Hughes | 2.8T, 0.4MA plasma.
H-modes Next shot: Repeat |
| Aug 3 2005 12:04:24:283PM | 1050803012 | Jerry Hughes | 2.8T, 0.4MA plasma.
More paltry H-modes Next shot: Ip-->0.6MA |
| Aug 3 2005 12:09:42:453PM | 1050803013 | Jerry Hughes | 2.8T, 0.6MA plasma.
2 H-modes Next shot: Repeat |
| Aug 3 2005 12:27:56:453PM | 1050803014 | Jerry Hughes | 2.8T, 0.6MA plasma.
2 H-modes Next shot: Ip-->0.8MA |
| Aug 3 2005 12:48:16:440PM | 1050803016 | Jerry Hughes | 2.8T, 0.8MA plasma. q95~2.6
1 H-mode, similar to shot 015. Next shot: Bt-->3.5T |
| Aug 3 2005 01:07:06:547PM | 1050803017 | Jerry Hughes | 3.6T, 0.8MA plasma.
H-modes, largely Ohmic. Next shot: Bt-->3.5T |
| Aug 3 2005 01:18:53:173PM | 1050803018 | Jerry Hughes | 3.5T, 0.8MA plasma.
3 H-modes, again largely Ohmic. Next shot: Ask Earl to flatten out right gap trace, per Wukitch's suggestion. |
| Aug 3 2005 01:25:46:190PM | 1050803019 | Jerry Hughes | 3.5T, 0.8MA attempt.
Fizzle. Next shot: Retry |
| Aug 3 2005 01:45:43:640PM | 1050803020 | Jerry Hughes | 3.5T, 0.8MA plasma
Long H-mode, sustained well past RF pulse. Significant density peaking in this discharge. Next shot: Ip-->1.0MA q95~2.6 |
| Aug 3 2005 02:09:10:737PM | 1050803021 | Jerry Hughes | 3.5T, 1.0MA plasma
Goes into H-mode, disrupts early. Next shot: Ip-->0.8MA |
| Aug 3 2005 02:09:38:720PM | 1050803022 | Jerry Hughes | 3.5T, 0.8MA plasma
Several H-modes, disrupts early. Next shot: Ip-->0.6MA |
| Aug 3 2005 02:46:17:673PM | 1050803023 | Jerry Hughes | 3.5T, 0.6MA plasma
3 H-modes, RF ratty late in the discharge. Overall, very similar shot to 007 in terms of performance, radiation, etc. Next shot: Repeat |
| Aug 3 2005 02:47:00:703PM | 1050803024 | Jerry Hughes | 3.5T, 0.6MA plasma
3 H-modes, RF still ratty late in the discharge. Next shot: Bt-->3.3T |
| Aug 3 2005 03:03:38:703PM | 1050803025 | Jerry Hughes | 3.5T, 0.6MA plasma
Similar to last shot. Field didn't come down as requested. Looks like monster density peaking. Next shot: Bt-->3.3T |
| Aug 3 2005 03:04:27:783PM | 1050803026 | Jerry Hughes | 3.3T, 0.6MA plasma
3 H-modes. RF unhappy. Next shot: Earl will decrease right gap, per Yijun's suggestion. |
| Aug 3 2005 03:18:00:360PM | 1050803027 | Jerry Hughes | 3.3T, 0.6MA plasma
3 H-modes. RF slightly better Next shot: Bt-->2.8T; Yijun will supplement heating with some E-port (2nd harmonic) |
| Aug 3 2005 03:29:25:940PM | 1050803028 | Jerry Hughes | 3.3T, 0.6MA plasma
2 H-modes. RF good, but disruption kills it before 3rd pulse. Next shot: Repeat, with RF delayed until flattop. |
| Aug 3 2005 03:45:00:127PM | 1050803029 | Jerry Hughes | 2.8T, 0.6MA plasma. 2 H-modes, 1st Ohmic. Disruption early. RF looks good. Next shot: Ip-->0.4MA |
| Aug 3 2005 03:56:14:237PM | 1050803030 | Jerry Hughes | 2.8T, 0.4MA plasma. Multiple H-modes with burts of Prad. Looks worse than shots 11,12, but the only real difference is E-port is on now, providing more power. Next shot: Drop RF program by 0.5MW. |
| Aug 3 2005 04:04:29:360PM | 1050803031 | Jerry Hughes | 2.8T, 0.4MA plasma. RF looks pretty good. Got 4 ELM-free H-modes Next shot: Bt-->3.3T. Lose E-port. Go back to the RF timing on shot 26. |
| Aug 3 2005 04:18:39:953PM | 1050803032 | Jerry Hughes | 3.3T, 0.4MA plasma. RF looks pretty good. Got 3 useful H-modes Next shot: Repeat. |
| Aug 3 2005 04:46:44:267PM | 1050803033 | Jerry Hughes | 3.3T, 0.4MA plasma. H-modes Next shot: Bt-->3.5T |
| Aug 3 2005 04:47:35:453PM | 1050803034 | Jerry Hughes | 3.5T, 0.4MA plasma. 3 useful H-modes Next shot: Bt-->3.3T, use single 0.5s flat RF pulse |
| Aug 3 2005 05:02:31:533PM | 1050803035 | Jerry Hughes | 3.3T, 0.4MA plasma. RF looks good, but H-mode drops half-way through RF pulse. Next shot: Ip-->0.6MA |
| Aug 3 2005 05:10:44:640PM | 1050803036 | Jerry Hughes | 3.3T, 0.6MA plasma. H-mode, long. End of run. |
| Physics Operator Comments | |||
| Aug 3 2005 08:47:42:703AM | Earl Marmar | overnight boronization was completed
followed by 3 hours of He ECDC and 0.5 hour D2 ECDC | |
| Aug 3 2005 09:05:45:203AM | 1050803001 | Earl Marmar | load from 1050428027
0.9 MA, SNL (note: this shot is using segment 3 after 0.1 seconds) load segment 1 from 1050726002 for post boronization startup fizzle |
| Aug 3 2005 09:21:11:267AM | 1050803002 | Earl Marmar | reduce prefill puff 1 msec to 16 msec
plasma some early hards |
| Aug 3 2005 09:40:15:797AM | 1050803003 | Earl Marmar | no pcs changes
plasma multiple h-modes early hards better but not gone |
| Aug 3 2005 09:47:43:970AM | 1050803004 | Earl Marmar | TF to 3.5 Tesla
plasma a couple of ohmic h-modes no early hards disrupt early in rampdown |
| Aug 3 2005 10:03:37:703AM | 1050803005 | Earl Marmar | no pcs changes
plasma no early hards H-modes with RF |
| Aug 3 2005 10:17:26:440AM | 1050803006 | Earl Marmar | Ip to 600 kA
target nl_04 to 6e19 plasma small level of early hards h-modes ramped all the way down |
| Aug 3 2005 10:29:44:267AM | 1050803007 | Earl Marmar | enable PG1 B side lower, 1 psi argon, 2 psi neon, 40 msec puff starting at 0.3 s
plasma early hesitation, no hards 2 h-modes, neutron rate ~1e13, H89 ~ 1.6 |
| Aug 3 2005 10:31:39:690AM | 1050803008 | Earl Marmar | Ip to 400 kA
target nl_04 to 4e19 |
| Aug 3 2005 11:08:36:767AM | 1050803009 | Earl Marmar | extend flattop to 1.8 seconds (all gains and programming changed in segment 3)
plasma 3 h-modes touched the inner wall at crossover (~1 second) TF starts ramping down at 1.6 seconds (forgot to extend to 1.8) |
| Aug 3 2005 11:43:20:173AM | 1050803010 | Earl Marmar | TF to 2.6 tesla
plasma 3 h-modes |
| Aug 3 2005 11:43:40:813AM | 1050803011 | Earl Marmar | TF to 2.8 tesla
plasma 2 h-modes |
| Aug 3 2005 11:49:25:097AM | 1050803012 | Earl Marmar | no pcs changes |
| Aug 3 2005 12:28:29:017PM | 1050803013 | Earl Marmar | increase prefill puff 1 msec to 17 msec
Ip to 600 kA target nl_04 to 6e19 plasma |
| Aug 3 2005 12:29:07:720PM | 1050803014 | Earl Marmar | no pcs changes
plasma |
| Aug 3 2005 12:28:56:280PM | 1050803015 | Earl Marmar | Ip to 800 kA
target nl_04 to 8e19 |
| Aug 3 2005 12:54:59:157PM | 1050803016 | Earl Marmar | going to feedback control of the a-coil currents, using Steve Wolfe's prescription from 1050722024
plasma earlier disruption (after first h-mode) |
| Aug 3 2005 01:09:56:127PM | 1050803017 | Earl Marmar | TF to 3.5 tesla
disable B-side-lower (argon/neon) plasma Li pellet at ~1.8, then disrupt RF tripping |
| Aug 3 2005 01:09:17:250PM | 1050803018 | Earl Marmar | reduce toroidal field 2%
re-enable Ar/neon puff, 20 msec duration on PG1 |
| Aug 3 2005 01:24:54:733PM | 1050803019 | Earl Marmar | fizzle |
| Aug 3 2005 01:30:50:313PM | 1050803020 | Earl Marmar | add 2 msec to prefill puff (now 20 msec)
decrease RCUR 2 mm between 1 and 1.4 seconds to keep outer gap steadier |
| Aug 3 2005 02:00:21:047PM | 1050803021 | Earl Marmar | Ip to 1.0 MA, end of Ip flattop to 1.5 seconds
target nl_04 to 1e20 plasma disrupt at 1.02 s (q_95 ~ 2.65) |
| Aug 3 2005 02:10:04:423PM | 1050803022 | Earl Marmar | Ip to 0.8 MA (flattop to 1.8 s)
target nl_04 to 8e19 plasma disrupt at 1.66 s (q_95 ~ 3.3) |
| Aug 3 2005 02:19:51:000PM | 1050803023 | Earl Marmar | Ip to .6 MA
target nl_04 to 6e19 plasma ramped all the way down multiple h-modes |
| Aug 3 2005 02:39:37:360PM | 1050803024 | Earl Marmar | no pcs changes
plasma very similar to 23 |
| Aug 3 2005 02:45:32:190PM | 1050803025 | Earl Marmar | TF to 3.3 tesla
but missed the change on the point at 1.8 seconds, so got slightly higher field plasma |
| Aug 3 2005 03:04:03:893PM | 1050803026 | Earl Marmar | TF to 3.3 tesla straight across
plasma 3 h-modes |
| Aug 3 2005 03:17:15:283PM | 1050803027 | Earl Marmar | add 1 msec to prefill puff (now 21 msec)
increase RCUR 2 mm (shrink outer gap by 4 mm) plasma |
| Aug 3 2005 03:28:19:737PM | 1050803028 | Earl Marmar | TF to 2.8 tesla
plasma 2 h-modes disrupts at 1.63 s ITB (ohmic) at end of shot |
| Aug 3 2005 03:47:00:517PM | 1050803029 | Earl Marmar | add 1 msec to prefill puff (now 22 msec) plasma disrupt at 1.63 seconds |
| Aug 3 2005 03:55:37:610PM | 1050803030 | Earl Marmar | Ip to 400 kA target nl_04 to 4e19 plasma ramps all the way down |
| Aug 3 2005 04:04:40:533PM | 1050803031 | Earl Marmar | no pcs changes
plasma |
| Aug 3 2005 04:18:15:140PM | 1050803032 | Earl Marmar | TF to 3.3 tesla
plasma 2 steady h-modes, 3'rd with RF trips |
| Aug 3 2005 04:34:51:877PM | 1050803033 | Earl Marmar | add 1 msec to prefill puff (now 23 msec)
plasma 3 h-modes, first steady, last 2 with RF trips |
| Aug 3 2005 04:56:17:593PM | 1050803034 | Earl Marmar | TF to 3.5 tesla
plasma |
| Aug 3 2005 04:56:52:487PM | 1050803035 | Earl Marmar | TF to 3.3 tesla
plasma |
| Aug 3 2005 05:02:22:547PM | 1050803036 | Earl Marmar | Ip to 600 kA
target nl_04 to 6e19 plasma |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 09:01:57:440AM | Plasma | Ok | |
| 2 | 09:14:30:720AM | Plasma | Ok | |
| 3 | 09:27:35:797AM | Plasma | Ok | |
| 4 | 09:41:15:877AM | Plasma | Ok | |
| 5 | 09:53:41:423AM | Plasma | Ok | |
| 6 | 10:06:20:923AM | Plasma | Ok | |
| 7 | 10:19:03:080AM | Plasma | Ok | |
| 8 | 10:31:31:017AM | Plasma | Ok | |
| 9 | 10:54:59:750AM | Plasma | Ok | |
| 10 | 11:23:30:093AM | Plasma | Ok | |
| 11 | 11:38:35:877AM | Plasma | Ok | |
| 12 | 11:50:57:800AM | Plasma | Ok | |
| 13 | 12:03:44:063PM | Plasma | Ok | |
| 14 | 12:16:13:640PM | Plasma | Ok | |
| 15 | 12:29:06:843PM | Plasma | Ok | |
| 16 | 12:43:26:360PM | Plasma | Ok | |
| 17 | 12:56:03:657PM | Plasma | Ok | |
| 18 | 01:09:29:157PM | Plasma | Ok | |
| 19 | 01:22:31:720PM | Plasma | Ok | |
| 20 | 01:34:57:750PM | Plasma | Ok | |
| 21 | 01:47:39:190PM | Plasma | Ok | |
| 22 | 02:00:09:453PM | Plasma | Ok | |
| 23 | 02:12:41:750PM | Plasma | Ok | |
| 24 | 02:26:35:300PM | Plasma | Ok | |
| 25 | 02:39:38:563PM | Plasma | Ok | |
| 26 | 02:52:31:470PM | Plasma | Ok | |
| 27 | 03:05:05:377PM | Plasma | Ok | |
| 28 | 03:17:53:563PM | Plasma | Ok | |
| 29 | 03:30:50:953PM | Plasma | Ok | |
| 30 | 03:44:41:907PM | Plasma | Ok | |
| 31 | 03:57:27:657PM | Plasma | Ok | |
| 32 | 04:10:10:000PM | Plasma | Ok | |
| 33 | 04:22:57:597PM | Plasma | Ok | |
| 34 | 04:35:25:550PM | Plasma | Ok | |
| 35 | 04:47:47:860PM | Plasma | Ok | |
| 36 | 05:00:27:390PM | Plasma | Ok | |