| Miniproposals | ||||||||||
|
| Operators | |
| Session leader(s): | Jerry Hughes |
| Physics operator(s): | Jim Irby |
| Engineering operator(s): | Bill Cochran,Bill Parkin |
| Engineering Operator Run Comment |
| automatically entered by signon - please replace with real comment |
| Session Leader Plans |
| Entered: Jul 29 2007 10:51:07:077PM |
| Author: Steve Wukitch |
| Session leader plan for 1070730 (pm)
MP485 ICRF impurity generation and B erosion SL: Wukitch PO: Irby Goal is to matching discharges to normal B-field operation to investigate impurity penetration and RF impurity generation. We would like to track both Mo and Ar concentrations in these discharges. SETUP: Gas: NINJA: J shelf capillary (1 psi Ar) Argon puff: 100 msec prior to RF power (1 psi Ar) Cryopump: Yes. ICRF: hopefully build upon morning run Run plan: Maximize ICRF power into 1 MA discharge in LSN building upon the morning run sequence. (3-4 discharges) After establishing standard discharge Puff Ar from J shelf capillary (2 shots) Puff Ar from B-side lower (2 shots) with cryopump Puff Ar from J shelf capillary (2 shots) Puff Ar from B-side lower (2 shots) Repeat with plasma current at 0.8 MA if time permits |
| Entered: Jul 30 2007 09:19:14:610AM |
| Author: Jerry Hughes |
| Session leader run plan for 1070730 (AM)
MP452: Reversed field pedestal studies SL: Hughes PO: Irby The goal for this experiment is to acquire and characterize H-modes and pedestals with the direction of field and current reversed, in order to make a comparison with similar discharges in the normal configuration. We will attempt to run a range of currents and densities in this configuration, tracking pedestal parameters (both dimensional and dimensionless), confinement and edge fluctuations. How these quantities differ between forward and reversed field will be studied and analyzed. Also of interest is comparing local L-H threshold conditions with those in the forward-field case. This experiment was attempted during the reversed field mini-campaign of 2006 (runs 1060524 and 1060602), but only a limited number of shots were obtained at 800kA. The main focus today will be to expand the range in current at which we have reversed field data. We will begin with a suitable 800kA target from 1070726 and repeat with density scan as necessary, then perform target density scans at 1.1MA and 0.5MA. SETUP: *5-hour boronization prior, 55mtorr foreline pressure with min/max/dwell of 60/85/75cm *Required diagnostics: Edge and core Thomson, ECE diagnostics, CXRS, bolometer arrays, PCI, reflectometry, Hirex. *Gas: --NINJA plenum loaded with 10psi D2 --Argon puff: 50ms at 0.3s (Argon at 1psi) *RF power requested: 0.70--1.00s: 3.0MW flat 1.00--1.30s: max. available, flat Tentative shot sequence (subject to change, depending on how the run is going): 1. Load 1070726020 (LSN 5.4T, 0.8MA rev.; nl04~8e19m^-2). Obtain H-modes of duration greater than 150ms. 2. Attempt to change edge collisionality by scanning target nl04 shot to shot. Try targets of a. 1.2e20m^-2 b. 1.0e20m^-2 c. 0.6e20m^-2 d. either 0.4e20m^-2 or 1.4e20m^-2, depending on results of a--c. 3. Go to 1.2MA. Attempt to obtain H-modes at target nl04 of a. 1.0e20m^-2 b. 1.2e20m^-2 c. 0.8e20m^-2 d. 0.6e20m^-2 e. either 0.4e20m^-2 or 1.4e20m^-2, depending on results of a--d. 4. Go to 0.6MA. Attempt to obtain H-modes at target nl04 of a. 0.6e20m^-2 b. 0.8e20m^-2 c. 0.4e20m^-2 d. either 0.3e20m^-2 or 1.0e20m^-2, depending on results of a--c. |
| Physics Operators Plans |
| Entered: Jul 29 2007 08:11:52:837AM |
| Author: Jim Irby |
| Phys Operator Run Plan for Monday, July 30, 2007
EF4 test to check fuses & SCRs (bipolar) PO: Irby MP#452A (1/2 day) Rev B pedestal studies Hughes "" MP#486 (1/2 day) ICRF imp. gen. & B erosion Wukitch "" --------------------------------------------------- The machine will be boronized on the Sunday before before the run: Boronize with 90%/10% boron bottle for a dP of approx 50 psi (do not exceed 5 hours). tc6 55 mTorr ef4 at 200 A rmin 60 rmax 85 rdwell 75 period 20/120 post boronization ECDC in D2 at 2e-4 Torr for 2 hours (can be done Monday morning rather than Sunday afternoon) ---------------------------------------------------- Gas setup: fill B-Top with 6 psi D2 Hybrid enabled (PG4) fill B-side lower with 1 psi Ar Enabled (PG1) leave B-side upper as is Hybrid DISABLED (PG2) fill B-main (C-side) with 40 psi D2 Hybrid enabled (PG3) NINJA plenum loaded with 10psi D2 Enable the following gate valves and shutters: ECE, VUV, Z-bolo shutters TORVAC: Gate valves open FMIT#1,2,3,4 required by 09:00 |
| Session Leader Summaries |
| Entered: Jul 30 2007 06:27:08:153PM |
| Author: Jerry Hughes |
| This run was intended to complete MP452a, which aims to generate H-modes in LSN
reversed field plasmas and compare the pedestal structure and edge relaxation mechanisms to those found in the normal field case. This run was beset with delays from start to finish (EF4 power supply problems, DAQ, failed Thomson gate valve), and didn't really get going until lunchtime, and so my AM run turned into a PM run. Steve Wukitch had been slated as SL for the afternoon, but he decided he wasn't likely to make any progress with his MP due to limits on J-port performance. ICRF generally did have problems coming up today, despite our best efforts to concoct a 5-hour boronization recipe that would not gum up the antennas. By shot 11, though, we were getting 2--3MW in from all sources and making H-modes. Density control was problematic, due to enhanced fueling seen when ICRF turned on into L-mode. The cryopump might have helped in this regard, but it would prevent a proper comparison with the forward-field shots in the database, all of which were unpumped. Of some concern to operation was the tendency of limiter tiles around D-port to light up and sometimes spark when the RF was turned on. Despite these problems, we were able to establish H-modes at 800kA and 600kA, with limited scans of target density. Many of these H-modes were quite hot, with pedestal Te reaching 1keV and central Te from 5 to 6keV. Naturally, energy confinement was quite good in these shots, with H_89>2. Very few ELMs were observed, and there was nothing especially remarkable about the pedestal widths, although detailed profile analysis will of course require more time. High current H-modes were essentially non-starters today. We took two shots at 1.2MA and one shot at 1.0MA and disrupted all of them, probably because of injections from D-port. H-modes worthy of continued analysis and insertion into the database were found on shots 8,10,11 and 13 (800kA) and 17,18,20 and 21 (600kA). |
| Physics Operator Summaries |
| Entered: Jul 31 2007 08:20:22:483AM |
| Author: Jim Irby |
| As soon as the ef4 supply was debugged and brought back into operation we began plasma operation on shot 6 without much difficulty. Because of the loss on f19, all the magnetics predictors were recalculated before the run, and Steve Wolfe was able to verify the settings had been updated with a new program he is developing (he found one predictor I had missed).
We had a disruption on shot 12 when we lowered the density request to 4e19/m^2. No gas was being injected after about 130 ms. Bruce mentioned he had similar problems at the low target density earlier, so we brought the request back up to 6e19/m^2 and recovered a full length discharge. On shot 14 we took the Ip request to 1.2 MA, and the density request to 1e20/m^2. We then had a full current disruption, possibly caused by an injection from the d-port antenna (as seen in the DIV2 view). On shot 15 we tried again at a lower density request, but disrupted even earlier. We finally had to reduce our Ip request to 600 kA to make sure we could run a full length discharge. To cure a MARFE at this current we had to reduce the density request to 6e19/m^2. On shot 19 we tried to move the plasma up 5 mm to help cure the problem at the D-Port antenna. This attempt resulted in an early disruption. Problems: We began the run today with a test of the EF4 supply to check if we had recovered from the fuse and scr loss last Friday. An engineering setup problem caused us to lose shot 1, and shots 2 and 3 showed we were unable to double swing the supply. After a couple of hours of debugging it was determined that a connector was loose and two pins possibly damaged. These problems were fixed, and we had a successful ef4 double swing test on shot 4. After a physop error on shot 5, we had our first plasma on shot 6. A data system (dispatcher) problem caused us to do a no power test on shot 9. The dispatcher was restarted. A couple of other slowdowns during the day. Injections at D-Port were a problem we did not really fix. score: tests/no power 01,02,03,04,05,09 duds fizzles plasmas 06,07,08,10,11,12,13,14,15,16 17,18,19,20,21 disruptions 12,14,15,16,19 |
| Session Leader Comments | |||
| Jul 30 2007 09:16:23:090AM | 1070730001 | Jerry Hughes | EF4 test. Verified YAG is working. |
| Jul 30 2007 09:16:41:933AM | 1070730002 | Jerry Hughes | Another EF4 test. |
| Jul 30 2007 11:01:33:133AM | 1070730003 | Jerry Hughes | Another EF4 test. Long-ish delay now to diagnose an EF4 supply problem.
Delay is taking upwards of an hour. |
| Jul 30 2007 12:15:34:380PM | 1070730004 | Jerry Hughes | The "final" EF4 test. |
| Jul 30 2007 12:15:53:920PM | 1070730005 | Jerry Hughes | No power shot. |
| Jul 30 2007 12:42:32:680PM | 1070730006 | Jerry Hughes | Plasma went as programmed. 800kA, 5.4T, target nl04~8e19. RF tries and retries, peak Prf of 2.3--2.4MW, but needs to be steadier. No H-mode. |
| Jul 30 2007 12:49:30:720PM | 1070730007 | Jerry Hughes | Plasma went as programmed. 800kA, 5.4T, target nl04~8e19. RF was steady at only 1.5MW. Keep trying. Ask Jim to lower target density to 7e19 for next shot. |
| Jul 30 2007 01:34:13:520PM | 1070730008 | Jerry Hughes | Plasma went as programmed. 800kA, 5.4T, target nl04~7e19. ICRF improved again.
H-mode at 0.85s with 2.2MW input RF. Trouble with RF matching the H-mode, and higher fueling result in a fairly low Te,PED of ~400eV. 2-phase transition behavior is evident on the reflectometry (110 GHz), with fluctuation spectrum evolving slowly during high-power L-mode phase, followed by classical ELM-free H-mode at 0.85s. Te,PED~300--400eV at the transition. And again, we see a prominent ne pedestal in the pre-H-mode phase, a few mm wide, with gradient a few times higher than typical L-mode. (cf. 1070726011) |
| Jul 30 2007 01:43:31:093PM | 1070730009 | Jerry Hughes | No power shot |
| Jul 30 2007 01:47:19:990PM | 1070730010 | Jerry Hughes | Still fueling like crazy in L-mode phase with RF, rising from 7e19 to 9e19.
Asking for nl04=5e19 on next shot. Yijun will back off early demand on J-port to try to steady it out. Signs of enhanced D-alpha in the H-modes, but there's no obvious QCM on the fluctuation diagnostics. |
| Jul 30 2007 02:01:22:207PM | 1070730011 | Jerry Hughes | Much improved performance from E and J. Access H-mode at 0.78s with 2.5MW, though
the plasma fuels up to almost 9e19 before transitioning. Te,95 in the 300+eV range prior to the transition. H-mode shows a clear evolution consisting of decreasing Te,PED, increasing ne,PED, with pe,PED basically constant. Next shot: lower nl04 to 4e19 to try to get the transition density down further. Also, Yijun will put in a ramp from 2--3MW from 0.7--1.0s. |
| Jul 30 2007 02:18:46:493PM | 1070730012 | Jerry Hughes | Early disruption. Not sure why. |
| Jul 30 2007 02:37:53:920PM | 1070730013 | Jerry Hughes | Good. Excessive density in the pre-H-mode phase is reduced now. This could be due
to the disruption, as Bruce predicted. Transition occurs when nl04~8e19, up from a target of 6e19. A little over 2MW required for L-H. Te,95~500eV prior to transition! Plenty of neuts. Wp hits >140kJ. |
| Jul 30 2007 04:05:42:273PM | 1070730014 | Jerry Hughes | Go to 1.2MA, nl04=1e20.
Result: disrupted at 0.88s. Never made it into H-mode, even though Prf made it to 2.4MW. Next shot: reduce nl04 program to 9e19 and also see if fueling during RF pulse is further reduced following disruption. Addendum: Discovered later that G-top gate valve close. |
| Jul 30 2007 03:33:14:703PM | 1070730015 | Jerry Hughes | Disrupts again, a little earlier. Again, no H-mode. D-port tiles are ligting up
and sparking on these last two shots. The RF traces are maddeningly smooth. Probably not going to accomplish much here, so drop Ip to 1MA, keeping programmed density. Need cell entry for Tom Toland to diagnose the G-top G.V., which got stuck closed following shot 14. Tom reports that the solenoid controlling that valve has failed and needs to be replaced. The delay continues. |
| Jul 30 2007 04:17:44:350PM | 1070730016 | Jerry Hughes | We're back up and running, after >1hr delay.
1MA, nl04=9e19. RF on, L-mode fuels, D-port lights up, top and bottom. No H-mode. Disrupts. Gaaa. Lower Ip to 600kA. nl04=6e19 |
| Jul 30 2007 04:49:15:790PM | 1070730018 | Jerry Hughes | Lower density improves thins here. D-port is still lighting up, but it's not a
killer. Jim will raise the plasma vertically by ~5mm to attempt to reduce the load on the tiles. Got density rise in L-mode phase again, followed by steady H-mode, ~600eV pedestal. The QCM is there on the 88GHz reflectometry channel, spinning down very fast to ~60kHz and getting replaced by bursty behavior, a la our old grassy ELMs. |
| Jul 30 2007 04:53:25:077PM | 1070730019 | Jerry Hughes | That didn't work so well. (Early disruption)
For our last trick, we will dial up shot 18 and lower the programmed nl04 to 4e19. |
| Jul 30 2007 05:17:45:967PM | 1070730020 | Jerry Hughes | Impressive H-modes. The first one has a ~1keV pedestal, with ne,ped<1.5e20.
Pedestal widths are unremarkable. |
| Jul 30 2007 05:22:51:627PM | 1070730021 | Jerry Hughes | Bonus shot.
Raised density program to 6e19, as on shot 18. It takes 2.6--2.7MW for H-mode to trigger. RF performs pretty well. We get some respectable low density H-modes. Brock fires a pellet into the second one. Other than killing the H-mode, it's fairly non-perturbative to the discharge. |
| Physics Operator Comments | |||
| Jul 30 2007 08:29:21:723AM | 1070730001 | Jim Irby | loaded shot 1070726020 (requires recal of mag predictors)
loaded seg 1 of 1070727002 into seg 1 Recal seg 2: rcur zcur zcur clearin rxl zxl rxu zxu ssep Recal seg 3: rcur zcur zcur clearin rxl zxl rxu zxu Recal seg 4: rcur zcur zcur clearin rxl zxl rxu zxu ssep ssep loaded into tree |
| Jul 31 2007 08:20:55:310AM | 1070730001 | Jim Irby | prepuff at 19 ms (as on 1070727002)
argon from 0.3 to 0.35 s (was at 0.30 to 0.36 s) loaded into tree Steve Wolfe discovered that I had not actually done the recal on ZXU in seg 2. All others seemed to be okay. Did recal and reloaded. Good check... I verified with Andy that the correction coils were setup as on 1070726 and enabled (I had not specified in physop plan). Turned off seg 2 for the EF4 double swing test loaded tree SETUP error on TMX supplies --- no power shot |
| Jul 30 2007 09:48:20:940AM | 1070730002 | Jim Irby | ef4 double swing test
ef4 did not double swing gas prefill okay no NINJA puff |
| Jul 30 2007 11:04:37:183AM | 1070730003 | Jim Irby | still no double swing in ef4
Bill going into power room to check out supply --- estimate of approx 45 minutes |
| Jul 30 2007 12:07:07:520PM | 1070730004 | Jim Irby | Found loose wire/connector in EF4 possibly with faulty pin connections. Not sure if this problem was the only one. Work in power room approx 2.5 hours
This shot will be another double swing test of EF4 EF4 test looks good Next shot try for plasma |
| Jul 30 2007 12:19:04:703PM | 1070730005 | Jim Irby | try for plasma
woops ---- forgot to turn on seg 2 and load --- no power test |
| Jul 30 2007 12:39:54:863PM | 1070730006 | Jim Irby | seg 2 enabled, loaded into tree
try again for plasma BP at INIT 4.3e-7 Torr plasma into rampdown density rise at 0.7 s probably from rf |
| Jul 30 2007 12:47:08:530PM | 1070730007 | Jim Irby | repeat DPCS
plasma into rampdown --- target density high at rf start |
| Jul 30 2007 01:02:59:937PM | 1070730008 | Jim Irby | nl_04 request from 9e19/m^2 to 7e19/m^2
loaded into tree plasma into rampdown --- h-mode |
| Jul 30 2007 01:12:53:323PM | 1070730009 | Jim Irby | No DPCS changes
However, note that Br0 has drifted up since since shot 6 as has prefill. ---- data system problem --- no power shot |
| Jul 30 2007 01:43:31:390PM | 1070730010 | Jim Irby | 20 minute delay on data system --- 2nd dispatcher restart required
no DPCS changes IGT 1.1e-6 Torr in CHECK plasma into rampdown --- h-modes Br0 back down to shot 6 level as was the prefill |
| Jul 30 2007 02:00:08:143PM | 1070730011 | Jim Irby | nl_04 request to 5e19/m^2
loaded tree plasma into rampdown --- 3.4 MW of ICRF for a while Wp 132 kJ |
| Jul 30 2007 02:07:20:497PM | 1070730012 | Jim Irby | nl_04 target to 4e19/m^2
loaded into tree disruption at 0.62 s radiation coming up by 0.57 s |
| Jul 30 2007 02:22:49:060PM | 1070730013 | Jim Irby | try again at nl_04 of 6e19/m^2 --- Bruce suggested that the target request was too low and that previous results indicated that could have caused the disruption. Note that on shot 12 we had no gas input after 0.13 s.
loaded into tree plasma into rampdown --- density down early compared to shots 11 and 12. |
| Jul 30 2007 02:41:23:753PM | 1070730014 | Jim Irby | nl_04 request to 1e20/m^2
Ip request 1.2 MA loaded into tree pellet enabled for 1.7 s disruption at 0.9 s injection at 0.65 s, then radiation ramping up starting at 0.875 s div2 view shows injection off lower right corner of d-port antenna |
| Jul 30 2007 03:00:38:790PM | 1070730015 | Jim Irby | nl_04 request to 9e19/m^2
dropped prefill from 19 to 18 ms loaded disruption at 0.805 s --- div2 again shows injections |
| Jul 30 2007 04:09:57:153PM | 1070730016 | Jim Irby | Ip request to 1.0 MA
loaded tree delay of to fix/debug G-Top TS gatevalve which remained closed following the disruption on shot 15. Tommy and Edgar find TS gatevalve solenoid blasting compressed air. Will have to replace solenoid. delay 1:14 plasma for 0.98 s --- D-Port antenna still glowing |
| Jul 30 2007 04:21:15:337PM | 1070730017 | Jim Irby | Ip request to 600 kA --- try to get another data point for Jerry before we adjust the gap.
loaded the tree plasma into rampdown --- MARFE |
| Jul 30 2007 04:36:54:293PM | 1070730018 | Jim Irby | nl_04 request to 6e19/m^2 --- fix MARFE??
loaded tree plasma into rampdown --- no MARFE still lots of activity on D-Port (DIV2) |
| Jul 30 2007 04:48:58:870PM | 1070730019 | Jim Irby | Try to raise plasma 5 mm to limit interaction on D-Port antenna
ZCUR from -0.009 to -0.004 m loaded tree plasma for 0.89 s --- didn't like moving up I guess |
| Jul 30 2007 05:05:42:153PM | 1070730020 | Jim Irby | reloaded shot 18 --- make sure we get ZCUR back to where it was happy
nl_04 request to 4e19/m^2 loaded tree plasma into rampdown |
| Jul 30 2007 05:21:19:360PM | 1070730021 | Jim Irby | nl_04 request back to 6e19/m^2 --- will try to better match rf to h-mode phase
plasma into rampdown --- Brock got his pellet into an h-mode All done.... Normal fields coming soon. |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 09:05:08:030AM | Test | Bad | Camac Setup problem |
| 2 | 09:14:53:230AM | Test | Bad | EF4 Doubleswing test |
| 3 | 09:37:16:693AM | Test | Bad | EF4 Double swing - no reverse bridge |
| 4 | 12:03:53:550PM | Test | Ok | EF4 test+/-2KA |
| 5 | 12:14:39:693PM | Plasma | Bad | No Power Shot |
| 6 | 12:26:41:703PM | Plasma | Ok | |
| 7 | 12:39:44:753PM | Plasma | Ok | |
| 8 | 12:52:33:910PM | Plasma | Ok | |
| 10 | 01:33:03:863PM | Plasma | Ok | |
| 11 | 01:47:52:503PM | Plasma | Ok | |
| 12 | 02:01:22:177PM | Plasma | Ok | |
| 13 | 02:17:09:930PM | Plasma | Ok | |
| 14 | 02:31:06:337PM | Plasma | Ok | |
| 15 | 02:46:20:743PM | Plasma | Ok | |
| 16 | 04:03:54:630PM | Plasma | Ok | |
| 17 | 04:17:05:960PM | Plasma | Ok | |
| 18 | 04:29:44:690PM | Plasma | Ok | |
| 19 | 04:42:24:893PM | Plasma | Ok | |
| 20 | 04:55:36:173PM | Plasma | Ok | |
| 21 | 05:10:20:130PM | Plasma | Ok | |
| System Availability | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Jul 30 2007 09:04:45:093AM | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||