| Miniproposals | ||||||||||
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| Operators | |
| Session leader(s): | Robert Granetz,Bruce Lipschultz |
| Physics operator(s): | Earl Marmar |
| Engineering operator(s): | Andy Pfeiffer,Bill Byford,Bill Parkin,Ed Fitzgerald |
| Engineering Operator Run Comment |
| MP #424 -- Gas jet disruption mitigation at higher plasma thermal energy |
| Session Leader Plans |
| Entered: Aug 10 2005 03:45:28:930PM |
| Author: Robert Granetz |
MP #424 -- Gas jet disruption mitigation at higher plasma thermal energy
and pressure.
Session leaders: R. Granetz, D. Whyte
Physics operator: E. Marmar
Overnight ECDC in D2; Bake at 60 C.
Run begins at 09:00 and ends at 17:00.
Power systems as on 1050722026 (1.0 MA, 5.4 T, SNL fiducial), except
reduce Btor slightly to 5.2 T to be compatible with 50 MHz from J, as well
as 80 MHz from E.
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 Ne 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 for this run.
Gas jet should have high-pressure ( >70 bar) helium bottle installed, WITH
HIGH-PRESSURE NEON AND ARGON BOTTLES READY TO BE SWITCHED IN DURING THE
RUN. (This will require SCBA access.)
Between-shot boronization should commence as soon as it is determined that
the gas jet system is working properly.
Torvac setup: unnecessary diagnostic gate valves (ECE) should be kept
closed on all gas jet shots.
Enable the following, assuming no vacuum problems:
Z-bolo shutters, VUV (yes, enable the VUV gate valve)
Necessary diagnostics:
IR camera
Fast PSI camera on B-horizontal, starting at t=0.800 s and He+0 filter.
The Ne+0 (and Ar+0 ?) filters should be available for later in the run.
Thomson scattering, with adjustable timing between the two lasers
Bolometry
AXUV array with reduced gain
Halo current Rogowskis
SX arrays with fast sampling window (t=0.795 to 0.820 s)
Mirnov Bp fluctuations
-------------------------------------------------------------------------------
ICRF Setup: All available transmitters in run on at 08:30. We'll want
maximum RF power starting right from shot 1
-------------------------------------------------------------------------------
Run plan: Start with helium at 70 bar, 2 ms. The goal is to get the same
extensive set of measurements, including IR images, as during the
previous gas jet run, but at significantly higher plasma stored
energy (>= 180 kJ) and pressure.
Another goal is to get helium VUV and visible line data to look at
opacity issues.
If the plasma stored energy is not significantly higher than
earlier runs (i.e. >=180 kJ), consider switching to another MP
during the day (after the opacity data has been obtained).
If the heating is good, then consider switching to the neon gas jet
(70 bar, 2 ms) later in the run. Note that this will require
SCBA access to the cell to close/open the diborane bottle.
|
| Physics Operators Plans |
| Entered: Aug 10 2005 06:34:13:460PM |
| Author: Earl Marmar |
| MP #424 -- Gas jet disruption mitigation at higher plasma thermal energy
and pressure. Session leaders: R. Granetz, D. Whyte Physics operator: E. Marmar Overnight ECDC in D2; Bake at 60 C. Run begins at 09:00 and ends at 17:00. Power systems as on 1050722026 (1.0 MA, 5.4 T, SNL fiducial) reduce Btor slightly to 5.2 T to be compatible with 50 MHz from J, as well as 80 MHz from E. 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 Ne Hybrid DISABLED (PG1) B-side upper with 15 psi He3 Hybrid enabled (PG2) fill B-main (C-side) with 40 psi D2 Hybrid enabled (PG3) No NINJA for this run. Gas jet should have high-pressure ( >70 bar) helium bottle installed, WITH HIGH-PRESSURE NEON AND ARGON BOTTLES READY TO BE SWITCHED IN DURING THE RUN. (This will require SCBA access.) We will need to be prepared to do between-shot boronization, but the diborane bottle should NOT be open at the beginning of the run. We will open the bottle after the first few successful shots. Torvac setup: unnecessary diagnostic gate valves (ECE) should be kept closed on all gas jet shots. Enable the following, assuming no vacuum problems: Z-bolo shutters, VUV (yes, enable the VUV gate valve) Necessary diagnostics: IR camera Fast PSI camera on B-horizontal, starting at t=0.800 s and He+0 filter. The Ne+0 (and Ar+0 ?) filters should be available for later in the run. Thomson scattering, with adjustable timing between the two lasers Bolometry AXUV array with reduced gain Halo current Rogowskis SX arrays with fast sampling window (t=0.795 to 0.820 s) Mirnov Bp fluctuations ------------------------------------------------------------------------------- ICRF Setup: All available transmitters in run on at 08:30. We'll want maximum RF power starting right from shot 1 |
| Session Leader Summaries |
| Entered: Aug 11 2005 05:22:45:677PM |
| Author: Bruce Lipschultz |
| MP340 - localization of boronization
We were given the run with 2.5 hours left and attempted to reproduce data from a 25 cm scan prior to 1050809012. Unfortunately the machine was in a bad state due to the VDE that was run just before we got the run. Ti and Mo injections were horrific. So, useless data. |
| Entered: Aug 11 2005 06:40:25:300PM |
| Author: Robert Granetz |
Session leader summary for Thursday 11 Aug 2005: MP #424 -- Gas jet disruption mitigation Session leader: R. Granetz/D. Whyte Physics operator: E. Marmar This was the 3rd run devoted to this MP. Today we were hoping to concentrate on high energy density, high pressure plasmas. But since the D-antenna is not working, and the J-antenna is running at 50 MHz with He3 minority heating, we never got more than 150 kJ, even with between-shot boronization. So that goal will have to wait until we get D-port back into operation, and probably J-port back to 78 MHz. But this was still a useful run because we got lots of IR camera images of the outer divertor during disruptions, good Thomson profiles, good AXUV profiles, etcetera. We ran helium gas jets and, curiously, the thermal and current quenches were occurring about 4 ms earlier than on 1050603. The only difference in the gas jet setup/system is that the overpressure relief valve (RLV1) setting was increased from 10 atm to 15 atm after the run on 03 June. This might also explain why today the gas inventory lost from the plenum now matches the measured increase in the torus (about 1.e23 He atoms) to within 10%. The disruption timing throughout the day was very reproducible, as was the peak halo current, which was 150 kA. We also had purposely forced an unmitigated VDE disruption (1050811009) for comparison. It had a significantly higher halo current of 227 kA. It also resulted in a shower of particles in the IR view. Unfortunately, the measurement of opacity in helium could not be carried out because the McPherson PLC controller doesn't turn off the high-voltage fast enough after the pressure increase. This will be worked on for the next gas jet run. After shot 1050811009 we changed gases to neon, but during the process I accidentally overpressured the gas jet pumping system and we decided to shut the system down and hand the run over to Bruce Lipschultz to continue boronization studies. After the run ended, we determined that the gas jet pumping system was still in working order. |
| Physics Operator Summaries |
| Session Leader Comments | |||
| Aug 11 2005 07:59:19:063AM | Robert Granetz | I hooked up the helium bottle to the gas jet system this morning, and Ron Rosati and I purged the system 3 times, then set the supply pressure to 1000 psi (70 bar), filled the plenum (no leaks to machine), and then fired a 2 ms pulse into the machine. Everything worked well. Torus pressure went to 650 mTorr. | |
| Aug 11 2005 08:07:50:717AM | Robert Granetz | I've shortened the gas jet pulse length to 1.3 ms (from 2.0 ms). (Helium is faster than neon and argon.) | |
| Aug 11 2005 08:29:04:397AM | Robert Granetz | Fired another helium gas jet test shot into the machine, this time with a pulse duration of 1.3 ms. Torus pressure reached 450 mTorr (compared to 650 mTorr with a 2.0 ms pulse...pretty linear). This didn't shut off the roughing pumps, which is a definite improvement, so I'll leave the pulse length at 1.3 ms for now. | |
| Aug 11 2005 12:37:00:677PM | 1050811001 | Robert Granetz | Shot -- Good shot. Helium gas jet fired. I_halo= 151 kA. Current quench starts at t=0.805 s. Current quench duration is about 2 ms. Quench started much earlier than last helium run (1050603). Maybe this has something to do with the higher setting on the pressure relief valve. Good IR imaging data. 2pifoil data are good. McPherson is still being checked out as far as its survival with the gas jet. It's taking a long time to pump the machine back down. Plenum gas: helium Pulse length (ms): 1.3 Plenum pre -pulse pressure (bar): 70 Plenum post-pulse pressure (bar): 58 Plenum change in pressure (bar): 12 |
| Aug 11 2005 09:59:44:860AM | 1050811002 | Robert Granetz | Shot -- Good shot. Helium gas jet fired. I_halo=149 kA. Current quench starts at t=0.8045 s. Current quench duration is about 2.5 ms Some problems with the MDSplus data acquisition. JT and Matt Reinke report that the McPherson PLC takes 400 ms to turn off the high voltage after the pressure rises. This is nowhere near good enough. Plenum gas: helium Pulse length (ms): 1.3 Plenum pre -pulse pressure (bar): 70 Plenum post-pulse pressure (bar): 57 Plenum change in pressure (bar): 13 |
| Aug 11 2005 10:09:48:123AM | 1050811002 | Robert Granetz | Plasma thermal energy was only 140 kJ, with an RF power of 3+ MW |
| Aug 11 2005 10:19:36:447AM | 1050811002 | Robert Granetz | Some of the camac data was lost. |
| Aug 11 2005 12:19:44:840PM | 1050811002 | Dennis Whyte | TS profiles at 0.8047 showsd Te decreased to ~ 100 eV and
ne~1.5e21 m-3. This is just at the end of the TQ but before the current bump. Suspicious if this is the CQ temperature since we are getting a 2 ms CQ time. |
| Aug 11 2005 10:34:12:363AM | 1050811003 | Robert Granetz | Fizzle. Gas jet fired anyway. Good background IR images. PSI camera fired at the right time. |
| Aug 11 2005 10:53:51:183AM | 1050811004 | Robert Granetz | Shot -- Good shot. Helium gas jet fired. I_halo=147 kA. Current quench starts at t=0.805 s. Current quench duration is about 3 ms 136 kJ, some RF faulting. Good IR. Good AXUV. Plenum gas: helium Pulse length (ms): 1.3 Plenum pre -pulse pressure (bar): 70 Plenum post-pulse pressure (bar): 57 Plenum change in pressure (bar): 13 After this shot, start between-shot boronization. |
| Aug 11 2005 12:30:39:913PM | 1050811004 | Dennis Whyte | TS profiles at 0.8042 show Te decrease and ne increase
reaching into r/a=0.7, while the target plasma inside of r/a =0.7 is more or less unchanged from before the gas. This is showing good He penetration (neutral or ion) far into the plasma before the TQ. V. Izzo shows that from edge ECE that the jet starts affecting the edge at .803 |
| Aug 11 2005 11:53:19:410AM | 1050811005 | Robert Granetz | Shot -- Good shot. Helium gas jet fired. I_halo=149 kA. Current quench starts at t=0.805 s. Current quench duration is about 2.5-3 ms. This is the first post-boronization shot. Prf=3.5 MW, Wth=150 kJ. Good xtomo array_1 data. Injected gas inventory matches the in-vessel inventory today. Maybe it's because of the increased pressure-relief valve setting. Plenum gas: helium Pulse length (ms): 1.3 Plenum pre -pulse pressure (bar): 70 Plenum post-pulse pressure (bar): 58 Plenum change in pressure (bar): 12 |
| Aug 11 2005 12:11:09:030PM | 1050811006 | Robert Granetz | Shot -- Good shot. Helium gas jet fired. I_halo=149 kA. Current quench starts at t=0.805 s. Current quench duration is about 2.5-3 ms. Good TS profile at t=0.8044 s. RF had a few faults. Wth=125 kJ. No boronization prior to this shot. Plenum gas: helium Pulse length (ms): 1.3 Plenum pre -pulse pressure (bar): 70 Plenum post-pulse pressure (bar): 57 Plenum change in pressure (bar): 13 |
| Aug 11 2005 12:23:17:807PM | 1050811006 | Dennis Whyte | TS profiles at 0.8044 shows the cooling front has
moved even further through the plasma. We are obtaining a very nice picture of the evolution of the density and Te through the TQ. |
| Aug 11 2005 12:31:46:100PM | 1050811006 | Robert Granetz | There's a clear n=1 component on the xtomo array_1 profiles starting around t=0.804 s. |
| Aug 11 2005 12:14:31:933PM | 1050811007 | Robert Granetz | There will probably be a lithium pellet injected on this shot at t=0.40 s. |
| Aug 11 2005 12:56:38:340PM | 1050811007 | Robert Granetz | Shot -- Good shot. Helium gas jet fired. I_halo=149 kA. Current quench starts at t=0.805 s. Current quench duration is about 2.5-3 ms Wth=127 kJ. Continuing to scan the TS timing. Plenum gas: helium Pulse length (ms): 1.3 Plenum pre -pulse pressure (bar): 70 Plenum post-pulse pressure (bar): 59 Plenum change in pressure (bar): 11 |
| Aug 11 2005 01:40:44:183PM | 1050811007 | Dennis Whyte | TS profiles at 0.8040 shows the cooling front has
somwhere between r/a =0.7 and 0.85. These shot 001 - 007 compose a very nice dataset from TS following the evolution of the cooling in the plasma shot time comment 001 .805 during curremt bump uniform low Te< 100 eV across all plasma 002 .8047 just before peak in current bump, "" 004 .8042 cooling front near r/a=0.65 005 .8042 same timing and same profile (very reproducible) 006 .8044 Cooling front (Te lowered, high ne) at r/a ~ 0.5 007 .8045 Only last channel in (r/a ~0.05) is still above 1 keV. 008 .8040 Early stages of cooling limited to edge (between r/a .7 and .085) |
| Aug 11 2005 01:22:41:703PM | 1050811008 | Robert Granetz | Shot -- Good shot. Helium gas jet fired. I_halo=156 kA. Current quench starts at t=0.805 s. Current quench duration is about 2.5-3 ms. This is the last shot for the helium gas jet today. Plenum gas: helium Pulse length (ms): 1.3 Plenum pre -pulse pressure (bar): 70 Plenum post-pulse pressure (bar): 58 Plenum change in pressure (bar): 12 |
| Aug 11 2005 01:23:42:550PM | 1050811008 | Robert Granetz | Next shot will be a forced VDE with no gas jet, so we can get comparison IR imaging data. |
| Aug 11 2005 01:36:28:620PM | 1050811009 | Robert Granetz | Shot -- Good shot. Forced VDE; no gas jet. I_halo=227 kA. Current quench starts at t=0.802 s. Current quench duration is about 2-2.5 ms. IR camera shows lots of particulates flying around after the disruption. Change to neon after this shot. No post-shot boronization for the next shot. |
| Aug 11 2005 06:41:39:223PM | 1050811009 | Robert Granetz | At the end of of the neon changeover/purging procedure I mistakenly overpressurized the gas jet pumping system. That's the end of the run for us. |
| Aug 11 2005 02:58:11:730PM | 1050811010 | Bruce Lipschultz | fizzle |
| Aug 11 2005 03:11:50:693PM | 1050811011 | Bruce Lipschultz | fizzle |
| Aug 11 2005 03:26:12:423PM | 1050811012 | Bruce Lipschultz | fizzle |
| Aug 11 2005 03:52:33:223PM | 1050811013 | Bruce Lipschultz | 1st shot after 70-95 boronization scan, flashing, 15 minutes
shot pretty awful with radiated power, Ti injections, RF tripping dPrad/dt = 5. H89 = 1.3 Wtot = 130. neuts = 13e12 repeat this shot |
| Aug 11 2005 04:48:18:970PM | 1050811016 | Bruce Lipschultz | 1st shot after boronization scan from 50-103 cm, no flashing, 15 minutes
incredible Mo injection at 0.89s and the confinement does not recover dPrad/dt = 2 H89 = 1.4 Wtot = 132. neuts = 17e12 try again |
| Aug 11 2005 04:51:50:810PM | 1050811017 | Bruce Lipschultz | 2nd shot after boronization scan from 50-103 cm, no flashing, 15 minutes
very ratty |
| Aug 11 2005 05:20:28:490PM | 1050811018 | Bruce Lipschultz | J port had difficulty staying on.
gave the shot over to Li pellets an NeSoX |
| Aug 11 2005 06:19:55:403PM | 1050811018 | Robert Granetz | It turns out that the Hovac pump is working just fine. During the gas changeover I overpressured the pump system, but the relief valve and the expansion chamber resulted in just some distortion of the short bellows section. It's all still leaktight and has now pumped back down to the normal base pressure. At some point we should replace the bellows section. |
| Physics Operator Comments | |||
| Aug 11 2005 08:55:24:950AM | Earl Marmar | Had overnight ECDC in D2 | |
| Aug 11 2005 09:23:47:670AM | 1050811001 | Earl Marmar | load 1050722026
load segment 1 from 1050810002 decrease prepuff to 20 msec (from 23) plasma startup looks ok decent plasma, rf tripping gas jet disruption as programmed |
| Aug 11 2005 10:02:49:940AM | 1050811002 | Earl Marmar | reduce prepuff to 17 msec (from 20)
plasma gas jet disruption as programmed 140 kJ before J-port trip some missing data (camac highway issue) |
| Aug 11 2005 10:26:53:007AM | 1050811003 | Earl Marmar | no pcs changes
dud fields look ok |
| Aug 11 2005 10:44:09:280AM | 1050811004 | Earl Marmar | Raise prepuff to 20 msec (from 17)
plasma bouncy startup, hards 135 kJ at gas-puff disruption (Prf = 3.5 MW) |
| Aug 11 2005 12:12:59:780PM | 1050811005 | Earl Marmar | 10 minute boronization prior to this shot
ECDC scan 50 to 103 cm, dwell at 70 100% duty factor on magnetron prepuff to 8 ms wait for P = 4e-6 at init plasma good shot 2*Prad_2pi = 1. MW before gas jet 150 kJ at gas jet induced disruption 1 rf trip (E-port) |
| Aug 11 2005 12:13:16:013PM | 1050811006 | Earl Marmar | no additional boronization prior to this shot
prepuff to 16 msec plasma 2*Prad_2pi ~ 2.4 MW before gas jet 120 kJ at gas-jet induced disruption |
| Aug 11 2005 04:19:06:997PM | 1050811007 | Earl Marmar | prior to this shot, boronize for 15 minutes
scan 50 to 103, dwell 70, 100% magnetron duty factor prefill to 8 msec go to init at torus gauge pressure 4e-6 plasma 127 kJ just before gas jet induced disruption |
| Aug 11 2005 01:47:38:040PM | 1050811008 | Earl Marmar | no boronization prior to this shot
prefill to 16 msec plasma 150 kJ and still rising at gas jet induced disruption |
| Aug 11 2005 01:52:19:693PM | 1050811009 | Earl Marmar | load zcur programming from 1050603005 (forced downward vertical disruption)
move the start of vertical push and turnoff of gains 50 msec earlier than on 1050603005 plasma boronization looks like it's pretty much worn off 125 kJ before RF trip downward VDE as desired |
| Aug 11 2005 02:51:00:953PM | 1050811010 | Earl Marmar | Switching to mp430, between shot boronization
prior to shot 10, 15 minutes boronization, scan from 70 to 95 cm, dwell at 82 cm, with magnetron modulation (1 Hz). load from 1050809011 import segment 1 from 1050811006 prefill to 8 msec, enter init at P = 4e-6 fizzle |
| Aug 11 2005 03:06:09:400PM | 1050811011 | Earl Marmar | prepuff to 16 msec
fizzle 25 kA bouncer |
| Aug 11 2005 03:20:12:347PM | 1050811012 | Earl Marmar | prepuff to 18 msec
fizzle 30 kA bouncer |
| Aug 11 2005 03:41:26:700PM | 1050811013 | Earl Marmar | prefill to 20 msec
plasma nice startup rf very trippy, 125 kJ |
| Aug 11 2005 03:49:22:510PM | 1050811014 | Earl Marmar | EF4 20 amp more negative before t=0
prefill puff to 21 msec plasma rf trippy 140 kJ |
| Aug 11 2005 04:21:35:747PM | 1050811015 | Earl Marmar | prior to this shot, boronize 15 minutes, sweep 50, 103, dwell at 70, 100% duty factor
prefill to 8 msec fizzle |
| Aug 11 2005 04:51:17:703PM | 1050811016 | Earl Marmar | prefill to 18 msec
plasma relatively big Mo injection early in H-mode steady EDA h-mode later, h89 ~ 1.2 |
| Aug 11 2005 04:51:23:453PM | 1050811017 | Earl Marmar | no pcs changes
no additional boronization prior to this shot plasma trippy RF, lots of injections |
| Aug 11 2005 05:03:11:840PM | 1050811018 | Earl Marmar | add 50 msec Ar/neon puff, starting at 0.3 seconds
plasma many j-port trips 3 h-modes |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 09:17:58:173AM | Plasma | Ok | |
| 2 | 09:43:52:710AM | Plasma | Ok | |
| 3 | 10:21:43:337AM | Plasma | Ok | |
| 4 | 10:35:15:770AM | Plasma | Ok | |
| 5 | 11:33:14:310AM | Plasma | Ok | |
| 6 | 11:52:14:240AM | Plasma | Ok | |
| 7 | 12:39:01:160PM | Plasma | Ok | |
| 8 | 01:02:46:463PM | Plasma | Ok | |
| 9 | 01:26:03:093PM | Plasma | Ok | |
| 10 | 02:44:41:143PM | Plasma | Ok | |
| 11 | 02:57:06:073PM | Plasma | Ok | |
| 12 | 03:13:58:880PM | Plasma | Ok | |
| 13 | 03:26:26:627PM | Plasma | Ok | |
| 14 | 03:39:07:247PM | Plasma | Ok | |
| 15 | 04:18:20:950PM | Plasma | Ok | |
| 16 | 04:30:51:887PM | Plasma | Ok | |
| 17 | 04:43:16:780PM | Plasma | Ok | |
| 18 | 04:58:42:073PM | Plasma | Ok | |