| Miniproposals | ||||||||||
|
| Operators | |
| Session leader(s): | Alexandre Parisot |
| Physics operator(s): | Robert Granetz |
| Engineering operator(s): | Gary Dekow |
| Engineering Operator Run Comment |
| MP#356 Mode conversion current drive in D[3He] at 50 MHz |
| Session Leader Plans |
| Entered: Aug 1 2005 05:42:53:613PM |
| Author: Alexandre Parisot |
| MP#356 Mode conversion current drive in D[3He] at 50 MHz.
The primary goal of this run is to measure net current drive from mode converted waves using loop voltage differences between co/counter phasing. This involves establishing an acceptable target discharge maximizing the efficiency (~ Te/(ne Zeff) according to parametrizations). This is a continuation of 150729. Special gas: He3 15 PSI, B-side Upper Diagnostics: standard set, with ECE and PCI (50 MHz, with localization). ECDC: overnight + setup for in-between shot ECDC. Run plan: 1) Start with 1050729033, and finish the sawtooth control studies: Sweep mode conversion layer through the q=1 surface in heating/counter/co current drive. (3 shots) Set toroidal field where maximum change was obtained in counter-current and co drive and ramp the power from J-port. (2 shots) 2) Load 1050729020 and continue discharge optimization. (5 to 10 shots) 3) Using the best target from 3), do a field scan to vary the deposition location around the magnetic axis, repeating discharges with +90, -90 and heating phasing. Look at loop voltage changes between co/counter to determine possible current drive. (15 shots) Target mode conversion layer locations: r/a = 0., 0.05, 0.10, 0.15, 0.2 on the HFS. Corresponding values of the B_T: 5.73T, 5.63T, 5.53T, 5.43T, 5.38T (will be readjusted from concentration estimates in part 2). |
| Physics Operators Plans |
| Entered: Aug 1 2005 11:45:24:863PM |
| Author: Robert Granetz |
Engineering setup for Tuesday, Aug 2005 MP #356 -- MCCD in D[He3] at 50 MHz (con't from 1050729, last Friday) Session leader: A. Perisot Physics operator: R. Granetz Overnight ECDC, and bake at 60 C. *** NOTE: Set up for between-shot ECDC *** Run begins at 09:00 and ends at 17:00. Power systems as on 1050729033 (0.6 MA, 5.2 T, inner wall limited, kappa=1.3) 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 Hybrid DISABLED (PG1) fill B-side upper with 15 psi He3 Hybrid enabled (PG2) fill B-main (C-side) with 40 psi D2 Hybrid enabled (PG3) No NINJA Enable the following gate valves and shutters, assuming no vacuum problems: ECE, VUV, Z-bolo shutters Important Diagnostics: Standard set, with ECE and PCI (50 MHz, with localization). ------------------------------------------------------------------------------- ICRF Setup: RF in run-on by 08:30, ready to go on first shot (J-port at 50 MHz) ------------------------------------------------------------------------------- Run plan: See the session leader's detailed posting. |
| Session Leader Summaries |
| Entered: Aug 2 2005 06:15:24:673PM |
| Author: Alexandre Parisot |
| This was a very good day in terms of machine operation, but
a painful day for the session leader. We started trying to reproduce the results on the sawtooth variations from Friday and extend the scan all the way throughout the q=1 surface. We ended up spending the entire day achieving this. The last three shots, 31, 32 and 33 are a good comparison co/counter and heating, although injections on 32 will have to be taken into account. Extending the scan from Friday to lower fields, we had multiple trips from J-port below 5T, so we tried to increase the concentration to do the scan at higher fields. In inner wall limited plasmas, this made us go closer to the density limit and MARFEs prevented us from getting good data. We went back to upper single null with feedback on the density to establish good discharges with Zeff < 3, nl04 ~ 0.6 (ne0 ~ 1.6 x 10^20) and Te0 ~ 3.5 keV with J-port at 2.5 MW. Disruptions or mutiple RF trips during the flattop repeatedly prevented us from obtaining resoneable scans until the last three shots. We made the scans go faster in field but the shots went all the way, with flat RF. We did not adress the loop voltage part of this experiment, although the USN targets we obtained are an improvement from Friday's discharges. They are probably a good place to start from for further experiments. Today and last Friday also left us with some puzzles about the relationship between 3He puff time, duration, the target density and the obtained 3He concentration, in upper single null and inner wall limited plasmas. While we finally obtained goods target, a better understanding of this would be helpful for further low density mode conversion experiments. Overall, the data collected on the sawtooth period changes is very encouraging. It seems consistent with current drive from mode converted waves around the q=1 surface, and will analyzed in detail. |
| Physics Operator Summaries |
| Entered: Aug 2 2005 05:08:21:453PM |
| Author: Robert Granetz |
Physics operator summary for Tuesday 02 Aug 2005:
MP #356 -- MCCD in D[He3] at 50 MHz (con't from 1050729, last Friday)
Session leader: A. Parisot
Physics operator: R. Granetz
The tokamak ran extremely reliably today, with no fizzles, duds, computer
hangs, nor power supply problems. We didn't have any cell accesses either,
so we managed to get a respectable number of shots despite the fact that a
significant amount of thinking by the session leader was required between
shots, leading to numerous DPCS changes by the physop. We mostly ran inner
wall equilibria (DPCS segment 2), with some upper null discharges (DPCS
segment 3) sprinkled in, especially later in the run day. There were a
number of early disruptions, the reasons for which were not at all clear.
The ICRF worked reasonably well, with many shots having 2.5 MW from J and
1.4 MW from E. The session leader's report summarizes the MCCD physics
results.
Scorecard: 33 plasmas
0 duds
0 fizzles
0 computer-related aborts
0 cycle tests
--------------
Total: 33 shot cycles |
| Session Leader Comments | |||
| Aug 2 2005 09:41:25:433AM | 1050802001 | Alexandre Parisot | Plasma. RF has trips after 1 sec, the plasma seems to be dithering into H-mode.
Zeff is below 2. Next. Repeat. |
| Aug 2 2005 09:55:30:010AM | 1050802002 | Alexandre Parisot | Plasma. Good shot. Heating phase.
No clear changes on the sawtooth period. The density reaches nl04 ~ 0.9 during the RF. Next. Change phasing for J-port. |
| Aug 2 2005 10:08:34:403AM | 1050802003 | Alexandre Parisot | Plasma. J-port faults out early.
No clear break-in-slope data so far, cannot check the 3He concentration. Next. Go to 5.4T flat to check the concentration. |
| Aug 2 2005 10:26:23:010AM | 1050802004 | Alexandre Parisot | Plasma. Faint break-in-slope data, concentration might be too low.
Next. Increase puff duration to 150 ms. |
| Aug 2 2005 10:46:17:170AM | 1050802005 | Alexandre Parisot | Plasma. Estimated concentration ~ 20 - 25 %.
I'll have to come back to that series of shots to understand why I could not estimate the concentration before. Should we expect a different relationship puff duration - concentration for the first shots of a day (after ECDC) ? Next. Decrase puff duration to 120 ms. |
| Aug 2 2005 10:56:38:980AM | 1050802006 | Alexandre Parisot | Plasma. Concentration still slightly over 20%, at least now we know what it is...
Move back to sawtooth control experiments. Next. Put back field ramp for shot 1 and decrase puff duration to 100 ms. |
| Aug 2 2005 11:35:21:043AM | 1050802008 | Alexandre Parisot | Plasma. No sawteeth in the discharge.
We see some MHD activity throughout the discharge, appearing before the RF turns on. Not quite sure what it is. Locked mode ? Next. Repeat. |
| Aug 2 2005 11:44:36:510AM | 1050802009 | Alexandre Parisot | Plasma. Sawteeth are back.
J-port has multiple trips after 1.2sec. Next. Repeat. |
| Aug 2 2005 01:12:44:327PM | 1050802015 | Alexandre Parisot | Plasma. J-port trips after 1.2. Is there anything special that the RF does not
like for fields below 4.95T ? Next. Ramp up the field from 4.7 to 5.2T |
| Aug 2 2005 01:21:22:340PM | 1050802016 | Alexandre Parisot | Plasma. J-port trips all the way now.
We'll have to change the concentration to do this scan at higher fields, this means higher concentrations. Next. Puff 150 ms 3He. |
| Aug 2 2005 01:47:44:167PM | 1050802018 | Alexandre Parisot | Next. Puff 200 ms 3He.
|
| Aug 2 2005 01:58:39:210PM | 1050802019 | Alexandre Parisot | Break-in-slope is clearer.
We are further off-axis, at the inner edge of the inversion radius. Next. Ramp the field from 5.4T to 5.0T. |
| Aug 2 2005 02:13:28:063PM | 1050802020 | Alexandre Parisot | Good break-in-slope data. Estimated concentration 25%.
E had multiple trips and J faulted out. The load was very different even on the early part, even though it was just a repeat until 0.8sec. Next. Repeat. |
| Aug 2 2005 02:24:22:567PM | 1050802021 | Alexandre Parisot | Good scan through the q=1 surface.
Next. Go to the opposite phasing for comparison. |
| Aug 2 2005 02:47:12:410PM | 1050802023 | Alexandre Parisot | Good scan through the q=1 surface, digital phase 230deg.
We have some trips on J-port late when changes in the sawtooth period occur. Let's try to move this structure earlier (without changing the field) Next. 3He puff duration 250ms. |
| Aug 2 2005 03:00:10:393PM | 1050802024 | Alexandre Parisot | Good scan through the q=1 surface, digital phase 230deg.
Density is going above nl04 ~ 1.0, some MARFEs. Next. Go to opposite phasing. |
| Aug 2 2005 03:02:49:533PM | 1050802024 | Alexandre Parisot | Good scan through the q=1 surface, digital phase 230deg.
Density is going above nl04 ~ 1.0, some MARFEs. We might be too high in concentration. Next. Go to opposite phasing. |
| Aug 2 2005 03:20:05:283PM | 1050802025 | Alexandre Parisot | Changes in sawtooth period seem related to the MARFEs, not clear effect
from the RF. We can run that high in concentration with this current. Our USN plasmas had lower densities, let's try going back to that. Next. Flat 5.5T USN, with 150ms 3He [0.2,0.35s], set target density to nl04 = 0.6 after 0.35s. |
| Aug 2 2005 03:37:06:517PM | 1050802026 | Alexandre Parisot | Plasma, parameters as desired. Disrupted at 1.1sec.
J-port ran with preprogrammed notch. Next. Increase puff duration to 200ms. |
| Aug 2 2005 03:48:08:563PM | 1050802027 | Alexandre Parisot | Plasma, disrupted at 0.95sec. Break-in-slope gives 30% 3He.
Next. Decrease puff duration to 150ms. Ramp Bt down from 5.4T to 5.0T. |
| Aug 2 2005 04:20:09:097PM | 1050802028 | Alexandre Parisot | Plasma, injections change the sawtooth period.
No clear effect from the RF. Next. Ramp field from 5.6T to 5.4T. |
| Aug 2 2005 04:21:06:067PM | 1050802029 | Alexandre Parisot | Plasma, disrupted at 1.1sec.
Next. Ramp field from 0.6s to 1.0s, 5.6T to 5.4T. |
| Aug 2 2005 04:33:42:113PM | 1050802030 | Alexandre Parisot | Plasma, good shot. RF turns on at 0.7s, my mistake.
Nice changes in the sawtooth period. Next. Ramp field from 0.6s to 1.0s, 5.6T to 5.0T. RF on 0.6-1.4s. |
| Aug 2 2005 04:41:28:847PM | 1050802031 | Alexandre Parisot | Plasma, nice shot.
Next. Go to the opposite phasing. |
| Aug 2 2005 04:53:38:753PM | 1050802032 | Alexandre Parisot | Plasma, nice shot.
Next. Go to heating phase. |
| Aug 2 2005 05:31:22:660PM | 1050802033 | Alexandre Parisot | Plasma, nice shot.
End of the run. |
| Physics Operator Comments | |||
| Aug 2 2005 09:34:50:637AM | 1050802001 | Robert Granetz | Plasma. Good shot. 0.6 MA, 5.2 T with a slight ramp down during the latter half of the shot. Inner wall limited. Prf_J=2.5 MW (50 MHz), Prf_E=1.0-1.4 MW (80 MHz). No runaways. Next shot: no DPCS changes. |
| Aug 2 2005 09:47:37:060AM | 1050802002 | Robert Granetz | Plasma. Good shot. Same as shot 01 except for some hard x-rays. Next shot: add 1 ms to pre-fill. Change J-port phasing. |
| Aug 2 2005 10:13:22:107AM | 1050802003 | Robert Granetz |
Plasma. Good shot, except that the runaways are getting worse. J-port turned
off very early.
Next shot: Change Btor programming to be 5.4 T, constant throughout the shot.
Also increase pre-fill by 2 more ms.
|
| Aug 2 2005 10:25:06:810AM | 1050802004 | Robert Granetz | Plasma. Good shot. Btor=5.4 T, constant. Hard x-rays went away. Prf_J=2.5 MW, Prf_E=1.4 MW. Next shot: increase He3 puff to 150 ms (from 100 ms). |
| Aug 2 2005 10:44:20:433AM | 1050802005 | Robert Granetz |
Plasma. Good shot. Hard x-rays are back. 2.5 MW from J; 1.3 MW from E.
Next shot: move PG3 preprogrammed gas a little earlier in time (3 ms) in segment 1
(Earl's suggestion). Shorten He3 pulse to 120 ms (from 150 ms).
|
| Aug 2 2005 10:53:41:277AM | 1050802006 | Robert Granetz |
Plasma. Good shot. Some early hard x-rays.
Next shot: change BTOR back to the 5.2 T with late ramp (copy from shot 03), and
reduce He3 puff back to 100 ms.
|
| Aug 2 2005 11:20:39:793AM | 1050802007 | Robert Granetz |
Plasma. Short, resistive shot, presumably done in by impurities. Lots of hard
x-rays too.
Next shot: increase pre-fill another 2 ms (to 40 ms !) and also remove pre-programmed
gas puff from PG3 in segment 2.
|
| Aug 2 2005 11:34:14:213AM | 1050802008 | Robert Granetz | Plasma. Good shot. Disrupted during rampdown. Good RF. Unusual MHD oscillations and no sawteeth on the ECE and SXR. Hard x-rays are gone. Next shot: no changes. Hope the sawteeth come back. |
| Aug 2 2005 11:42:31:090AM | 1050802009 | Robert Granetz | Plasma. Good shot. Hard x-rays remain at bay. Sawteeth are back. Next shot: reduce A-coil programming (as advised by Steve Wolfe). |
| Aug 2 2005 11:52:31:857AM | 1050802010 | Robert Granetz | Plasma. Early disruption, short resistive plasma. Hard x-rays. Next shot: increase pre-fill by 2 ms (to 42 ms !) |
| Aug 2 2005 12:08:33:963PM | 1050802011 | Robert Granetz | Plasma. Short, resistive plasma. No hard x-rays on this shot, so that's not the cause of the early disruptions. The "wide1" and "dant" video cameras show some injections. Next shot: repeat, no changes. |
| Aug 2 2005 12:26:51:560PM | 1050802012 | Robert Granetz |
Plasma. Another short, disruptive shot. I see one of the retros lighting up on the inboard
wall. Could this be causing the early disruption?
Next shot: try an upper single null to see if the plasma still disrupts. Do this by turning segment 3
on and segment 2 off, and then copying Btor, PG3, and PG2 pre-programming over as well.
|
| Aug 2 2005 12:37:48:027PM | 1050802013 | Robert Granetz | Plasma. Upper null. Disrupted at t=0.92 s. Slight vertical instability early in the discharge. DANT video view shows lots of dust/particulates. Next shot: tweak early ZXU down a little. |
| Aug 2 2005 12:49:09:213PM | 1050802014 | Robert Granetz | Plasma. Upper null. Lasted longer (disrupted at t=1.1 s). Next shot: go back to the inner wall limited equilibrium (shot 12), but add the PG3 pre-programmed D2 gas puff back in (copied from earlier today). |
| Aug 2 2005 12:59:51:043PM | 1050802015 | Robert Granetz |
Plasma. Inner wall limited again. Good shot. Maybe the PG3 puff at t=0.1 s really helps avoid a
disruption.
Next shot: reverse the Btor ramp. Have Btor=4.7 T early in the flattop and then ramp it up to 5.2 T
later in the flattop.
|
| Aug 2 2005 01:17:58:887PM | 1050802016 | Robert Granetz |
Plasma. Good shot. Btor reverse ramped, as desired. RF didn't like it though. Some early
runaways.
Next shot: return to the original Btor ramp (copy from shot 15). Also increase
He3 puff to 150 ms (from 100 ms)
|
| Aug 2 2005 01:30:08:823PM | 1050802017 | Robert Granetz | Plasma. Disrupted at t=0.8 s. Next shot: program Btor for 5.4 T, constant. |
| Aug 2 2005 01:40:41:823PM | 1050802018 | Robert Granetz | Plasma. Good shot. RF had numerous faults. Next shot: increase He3 puff to 200 ms (from 150 ms). |
| Aug 2 2005 01:59:50:570PM | 1050802019 | Robert Granetz | Plasma. Good shot. Next shot: program in a Btor ramp from 5.4 T at t=0.8 s down to 5.0 T at t=1.4 s for remainder of flattop |
| Aug 2 2005 02:08:26:283PM | 1050802020 | Robert Granetz | Plasma. Good shot. Btor ramped as desired. Both E nor J antennas faulted alot. Next shot: no DPCS changes. Work on the RF coupling. |
| Aug 2 2005 02:21:26:423PM | 1050802021 | Robert Granetz | Plasma. Good shot. No hard x-rays. Zeff=1.5. Good RF performance. Next shot: no DPCS changes. |
| Aug 2 2005 02:34:56:720PM | 1050802022 | Robert Granetz | Plasma. Disrupted at t=0.96 s. Next shot: no DPCS changes. |
| Aug 2 2005 02:45:25:970PM | 1050802023 | Robert Granetz | Plasma. Good shot, full length again. I don't know why some of these disrupt early. It seems to be unrelated to our control. Pretty good RF performance. Next shot: increase He3 puff to 250 ms (from 200 ms). |
| Aug 2 2005 03:02:45:817PM | 1050802024 | Robert Granetz | Plasma. Good shot. Seemed to be some marfing on the inboard midplane, which doesn't make sense, given that we're running inner wall limited plasmas. Good RF performance. Next shot: no DPCS changes |
| Aug 2 2005 03:25:56:830PM | 1050802025 | Robert Granetz | Plasma. Good shot. RF was good until t=1.16 s, then starts faulting alot. Next shot: upper null (turn on segment 3), Btor flat at 5.5 T, He3 puff 0.2-0.35 s (150 ms duration), nl_04=0.35e20 until t=0.4 s and then ramp up to 0.6e20 m-2 for remainder of flattop. Also copied PG3 programming. |
| Aug 2 2005 03:36:11:300PM | 1050802026 | Robert Granetz | Plasma. Good shot. Disrupted at t=1.28 s. Got all the requested parameters and changes. RF looks very good. Next shot: increase He3 puff to 200 ms duration (from 150 ms). |
| Aug 2 2005 03:50:02:567PM | 1050802027 | Robert Granetz |
Plasma. Disrupted at t=0.98 s. Upper null (DPCS segment 3). E-port antenna is not on.
Next shot: decrease He3 puff duration to 150 ms (from 250 ms) and change Btor
to start at 5.4 T and ramp down to 5.0 T during the latter portion
of the discharge.
|
| Aug 2 2005 04:05:02:800PM | 1050802028 | Robert Granetz | Plasma. Good shot, full length upper null plasma, finally. J-Port =2.5 MW, E-port=0. Next shot: program Btor to ramp from 5.6 T down to 5.2 T. |
| Aug 2 2005 04:19:41:173PM | 1050802029 | Robert Granetz |
Plasma. Te0 gradually decays after 0.95 s, as do the sawteeth, followed by a disruption at
t=1.11 s. Is this a locked mode?
Next shot: increase A-coil programming by 500 amps. Also change timing of Btor
ramp to make it a little earlier.
|
| Aug 2 2005 04:30:52:877PM | 1050802030 | Robert Granetz |
Plasma. Good shot. Full length upper null discharge. J-port timing wasn't changed, however.
Next shot: modify the Btor ramp to continue dropping Btor to 5.0 T at t=1.4 s. Also change
RF timing appropriately.
|
| Aug 2 2005 04:41:45:033PM | 1050802031 | Robert Granetz | Plasma. Good shot. Full-length upper null plasma. Btor ramps as requested. Prf_J=2 MW. Next shot: no DPCS changes. |
| Aug 2 2005 04:56:24:877PM | 1050802032 | Robert Granetz | Plasma. Good shot. Full-length upper null plasma. Prf_J=2.4 MW, Prf_E=0. Next (last) shot: no DPCS changes. |
| Aug 2 2005 05:06:45:003PM | 1050802033 | Robert Granetz | Plasma. Good shot. Full-length upper null plasma. Prf_J=2.2 MW, Prf_E=0. No hard x-rays. End of run. |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 09:25:08:277AM | Plasma | Ok | |
| 2 | 09:39:45:183AM | Plasma | Ok | |
| 3 | 09:55:50:200AM | Plasma | Ok | |
| 4 | 10:11:23:623AM | Plasma | Ok | |
| 5 | 10:29:09:607AM | Plasma | Ok | |
| 6 | 10:45:23:310AM | Plasma | Ok | |
| 7 | 10:58:12:997AM | Plasma | Ok | |
| 8 | 11:21:31:840AM | Plasma | Ok | |
| 9 | 11:34:48:480AM | Plasma | Ok | |
| 10 | 11:47:15:933AM | Plasma | Ok | |
| 11 | 11:59:36:543AM | Plasma | Ok | |
| 12 | 12:12:24:620PM | Plasma | Ok | |
| 13 | 12:27:02:857PM | Plasma | Ok | |
| 14 | 12:39:38:747PM | Plasma | Ok | |
| 15 | 12:52:09:623PM | Plasma | Ok | |
| 16 | 01:04:58:090PM | Plasma | Ok | |
| 17 | 01:19:02:623PM | Plasma | Ok | |
| 18 | 01:33:18:997PM | Plasma | Ok | |
| 19 | 01:45:47:760PM | Plasma | Ok | |
| 20 | 01:59:59:727PM | Plasma | Ok | |
| 21 | 02:12:36:613PM | Plasma | Ok | |
| 22 | 02:25:03:173PM | Plasma | Ok | |
| 23 | 02:37:45:423PM | Plasma | Ok | |
| 24 | 02:50:42:863PM | Plasma | Ok | |
| 25 | 03:03:46:313PM | Plasma | Ok | |
| 26 | 03:25:39:220PM | Plasma | Ok | |
| 27 | 03:38:25:020PM | Plasma | Ok | |
| 28 | 03:51:04:440PM | Plasma | Ok | |
| 29 | 04:05:25:253PM | Plasma | Ok | |
| 30 | 04:21:35:003PM | Plasma | Ok | |
| 31 | 04:34:21:770PM | Plasma | Ok | |
| 32 | 04:47:14:393PM | Plasma | Ok | |
| 33 | 05:01:11:050PM | Plasma | Ok | |