| Miniproposals | ||||||||||
|
| Operators | |
| Session leader(s): | Jerry Hughes |
| Physics operator(s): | Robert Granetz |
| Engineering operator(s): | Andy Pfeiffer,Gary Dekow |
| Engineering Operator Run Comment |
| MP514: Influence of magnetic topology on the H-mode pedestal Session lea |
| Session Leader Plans |
| Entered: Aug 21 2007 08:40:03:837AM |
| Author: Jerry Hughes |
| Run plan for 1070821
MP514: Influence of magnetic topology on the H-mode pedestal This experiment is intended to examine the detailed dependence of H-mode pedestal parameters on magnetic balance. We propose to make ICRF-heated H-modes in discharges with varied magnetic topology. Discharges will be swept dynamically between LSN and USN, while maintaining H-mode throughout. A companion set of H-modes will be made in static topologies, including both DN and SN with varied SSEP. SETUP: **Overnight boronization: rmin/rmax/rdwell 60/80/75 scan 20/120 foreline pressure 50mTorr (Roman will control resonance location during initial ~1/2-hour of boronization, in order to make measurements with S^3. Afterwards, revert to the above recipe.) No ECDC requested. **Diagnostics Edge and core Thomson, ECE diagnostics, CXRS, bolometer arrays, PCI, reflectometry, Hirex **DNB ready by first shot 6A max current desired, 30/15ms ON/OFF **Gas NINJA plenum loaded with 10psi D2 Argon puff: 50ms at 0.3s (Argon at 1psi) **ICRF 3MW flat from 0.5 to 1.5s SHOT SEQUENCE: 1.) LSN Load from 1070803008. This is a shot with SSEP swept from -4mm to +4mm using a programmed ramp in ZCUR. Make the following changes: --Raise Ip to 800kA --Raise nl04 to 8e19 by 0.5s --Lower and flatten ZCUR program so that SSEP stays at ~ -5mm throughout flattop 2.) Ramps through DN a.) Program ZCUR ramp to obtain SSEP: -5mm --> +5mm over 0.7s --> 1.5s b.) Increase ramp rate: -5mm --> +5mm over 0.7s --> 1.1s, then flat +5mm c.) Check hysteresis: -5mm --> +5mm over 0.7s --> 1.1s, then +5mm --> -5mm over 1.1s --> 1.4s d.) Program a ZCUR jog at 0.7s: -5mm --> +5mm; and at 1.1s: +5mm --> -5mm 3.) Static topology, with some back-end ramps: a.) SSEP = +5mm over 0.7 --> 1.1s, then ramp to -5mm over 1.1s --> 1.5s b.) SSEP = +2mm over 0.7 --> 1.1s, then ramp to -5mm over 1.1s --> 1.5s c.) SSEP = 0mm over 0.7 --> 1.1s, then ramp to +5mm over 1.1s --> 1.5s d.) SSEP = 0mm over 0.7 --> 1.1s, then ramp to -5mm over 1.1s --> 1.5s e.) SSEP = -2mm over 0.7 --> 1.1s, then ramp to +5mm over 1.1s --> 1.5s 4.) Repeat any of the above shots for which additional data are desired. 5.) Larger ramps, as feasible a.) SSEP: -5mm --> +10mm over 0.7 --> 1.1s, then flat +10mm through 1.5s b.) SSEP: +10mm --> -5mm over 0.7 --> 1.1s, then flat -5mm through 1.5s c.) SSEP: -10mm --> +10mm over 0.7 --> 1.1s, then flat +10mm through 1.5s d.) SSEP: +10mm --> -10mm over 0.7 --> 1.1s, then flat -10mm through 1.5s e.) SSEP: -5mm --> +15mm over 0.7 --> 1.1s, then flat +15mm through 1.5s f.) SSEP: +15mm --> -5mm over 0.7 --> 1.1s, then flat -5mm through 1.5s 6.) Static topology a.) SSEP = +10mm b.) SSEP = +15mm 7.) Repeat any of the above shots for which additional data are desired. |
| Physics Operators Plans |
| Entered: Aug 21 2007 07:37:52:397AM |
| Author: Robert Granetz |
Engineering setup for Tuesday 21 Aug 2007
MP#514 Influence of magnetic topology on H-mode pedestal
Session leader: J. Hughes
Physics operator: R. Granetz
Overnight boronization:
Rmin/Rdwell/Rmax = 60/80/75 cm.
scan 20/120
foreline pressure 50 mTorr
No ECDC requested
Power systems as on 1070803008.
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 DISABLED (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: LSN, then ramp through DN, then various static topologies.
For shot 1 setup:
Load from 1070803008. This is a shot with SSEP swept from -4 mm to
+4 mm using a programmed ramp in ZCUR. Make the following changes:
-- Raise Ip to 0.80 MA
-- Raise nl_04 to 0.8e20 by t=0.5 s
-- Lower and flatten ZCUR program so that SSEP stays at ~ -5 mm
throughout flattop
|
| Session Leader Summaries |
| Entered: Aug 21 2007 05:08:46:867PM |
| Author: Jerry Hughes |
| Run summary for 1070821
MP514: Influence of magnetic topology on the H-mode pedestal This experiment was intended to examine the detailed dependence of H-mode pedestal parameters on magnetic balance. We set out to make ICRF-heated H-modes in discharges with varied magnetic topology. Plasmas all had Ip=800kA, Bt=5.4T and a programmed nl04 of 8x10^2 m^-2. The cryopump was not utilized, and thus all pedestals obtained their "natural" density from wall fueling alone. The first several shots today were spent largely on boronization recovery and discharge optimization. The plasmas started out rather overdense, suggesting that perhaps an hour or two of He ECDC should perhaps have been performed post-boronization. It took a few shots edge neutral pressures to come down and for ICRF matching to be optimized, but by shot 8 we were starting to get steady RF at the 3MW level, into stationary H-modes. We had persistant injections early in the discharges (usually around 0.65 to 0.7s), and so we delayed the RF onset until 0.75s on shot 10. After this change, we started to have some good results scanning SSEP. We generally observed significant reduction in H-mode pedestal density as the discharges transitioned from LSN to USN. Typical values observed for n_e,PED were 2.6x10^20 m^-3 in LSN and 2.0x10^20 m^-3 in USN. The lower confined density was correlated with reduced Prad, but, contrary to our expectations and prior experience, this did not always result in a higher temperature pedestal. A degree of hysteresis in the density pedestal response was also observed in sweeps from LSN to USN and back, with n_e,ped mostly recovering its original LSN value. Pedestal and global parameters seemed to be extremely sensitive to magnetic balance with SSEP in the range of 0 to +4mm, with the suggestion of a sweet spot of around +2mm, in which a long steady H-mode could be maintained with fairly low density and low radiated power (shot 24). Attempts to reproduce this behavior with additional ICRF power on shots 30 and 31 were less successful, but this may have been the consequence of a very tired boronization. Shot 32 was an attempt to check the response of the pressures behind the upper and lower divertor in an Ohmic discharge, as a means of checking the accuracy of SSEP from EFIT. Unfortunately it disrupted at 300kA. Overall the run was successful in producing a lot of H-mode data in near DN configurations. The pedestal response to topology, and the subsequent confinement properties of the plasmas, will be examined carefully. |
| Physics Operator Summaries |
| Entered: Aug 21 2007 05:06:07:393PM |
| Author: Robert Granetz |
Run summary for Tuesday 21 Aug 2007
MP#514 Influence of magnetic topology on the H-mode pedestal
Session leader: J. Hughes
Physics operator: R. Granetz
This run involved running configurations with several different SSEP
values, including many shots with SSEP scans from lower null to upper null
and vice versa. The SSEP scans were actually done using ZCUR control, with
appropriate adjustments to the CLEARIN reference point. The machine and
the ICRF ran very well, with long, constant 3 MW pulses the norm for today.
Much pedestal data were obtained during the SSEP scans. See the session
leader's summary for more info.
Other than a few fizzles and the usual small N2 leak, the only notable
operational issue was on shot 10, when a number of diagnostic gate valves
closed during the shot (GPC, Thomson, TCI, and DNB). Apparently TORVAC
removed their permissives for some unknown reason. It did not recur.
Scorecard: 27 plasmas
0 duds
4 fizzles
0 power supply tests
1 no-power MDS shot cycles
--------------
Total: 32 shot cycles
|
| Session Leader Comments | |||
| Aug 21 2007 09:31:50:213AM | 1070821002 | Jerry Hughes | First plasma attempt.
Bt=5.4T, Ip=800kA SSEP is -4mm to -3mm thorughout flattop. Plasma is overdense, surpassing the target 8e19 even before ICRF comes on. RF is intermittent, but does trigger an H-mode at 1s. This is a dense, cold H-mode, with n_e,PED~2.6e20, T_e,PED<250eV. Mostly Ohmic. Re-run with lower SSEP. |
| Aug 21 2007 09:47:09:423AM | 1070821003 | Jerry Hughes | Bt=5.4T, Ip=800kA
SSEP is -5mm to -4mm thorughout flattop. Seems to go IW limited at ~0.45s. There is also a burp of density there, which might be due to NINJA puff. Plasma is still overdense, but ICRF has improved. LONG steady H-mode, sustained even as Prf drops to 600kW. n_e,PED~2.6e20. Te,PED~250--300eV. Lower SSEP more. |
| Aug 21 2007 10:25:44:373AM | 1070821004 | Jerry Hughes | Bt=5.4T, Ip=800kA (but not full current until H-mode formation)
SSEP is -7mm to -5mm throughout flattop, oscillatory. H-modes with injections. Disrupts in rampdown. Steady H-mode after 2nd injection: n_e,PED~2.6e20. Te,PED~250--300eV. Next: Retry with improved current feedback. |
| Aug 21 2007 10:15:15:500AM | 1070821005 | Jerry Hughes | Bt=5.4T, Ip=800kA by 0.5s
SSEP is -7mm to -5mm throughout flattop, more ragged. Left gap improved at ~0.45s. Not as heavily fueled; nl04~9e19 when RF comes on. Steady H-mode, with Prf ranging from 1.5--3MW. Some injections. Yijun reports J-port is feeling the high neutral pressure, but it is improving as we continue to run discharges. Early H-mode, with lower power: n_e,PED~2.6e20. Te,PED~300eV. Late H-mode, with higher power: n_e,PED~2.3e20. Te,PED~400--600eV. Next: Retry. Kenny will disable NINJA to see if the puff is affecting our density in L-mode. |
| Aug 21 2007 10:30:58:820AM | 1070821006 | Jerry Hughes | Bt=5.4T, Ip=800kA
Dirty H-modes. Reinke says we're injecting copper! Quite a large number of sparks flying around afterwards. Disrupts before it really gets started. NINJA was off, and so canot explain the bump in density at 0.45s |
| Aug 21 2007 10:33:13:057AM | 1070821007 | Jerry Hughes | Fizzle |
| Aug 21 2007 11:03:26:447AM | 1070821008 | Jerry Hughes | Plasma. Full length. 5.4T, 800kA.
H-modes, with early injections. SSEP~ -5mm in flattop Not a bad H-mode after .8s. ne,PED~2.4e20, Te,PED~400-600eV Next: Insert a ZCUR ramp from 1.0s to 1.5s for topology sweep. |
| Aug 21 2007 11:12:56:490AM | 1070821009 | Jerry Hughes | Plasma. Full length. 5.4T, 800kA.
H-modes, with early injection. Big injections are consistently coming in at 0.65--0.70s. SSEP~ -5mm until 1s, then scans to +3mm H-mode comes to near steady state by 1s. ne,PED~2.6e20 before 1s, then drops during SSEP scan. Te,PED~400-600eV Next: Yijun will delay RF onset to 0.75s. Bob will adjust ZCUR scan to obtain final SSEP of +5mm. |
| Aug 21 2007 11:49:53:500AM | 1070821010 | Jerry Hughes | Plasma. Full length. 5.4T, 800kA.
Avoided the big injections into H-mode this time. Prf=3MW by 1s. SSEP~ -5mm until 1s, then scans to almost +5mm. Nice scan. Upper chamber pressure jumps up as SSEP crosses through 0. ne,PED~2.6e20 before 1s, then drops during SSEP scan. Te,PED drops too, butonly after we go through DN. It looks like the Te,ped and grad-Te are much higher when |SSEP|<2mm. Multiple gate valves closed on this shot: ECE, TS, TCI. Next: Work on J-port match. Bob will make a further adjustment to the SSEP scan. |
| Aug 21 2007 11:50:06:987AM | 1070821011 | Jerry Hughes | Fizzle. |
| Aug 21 2007 12:58:04:653PM | 1070821012 | Jerry Hughes | Plasma. Full length. 5.4T, 800kA.
Great RF trace. Prf=3MW steady from 0.9s to 1.4s. SSEP~ -4mm at 1s, then scans to +7mm by 1.5s. ne,PED~2.4e20 at beginning of scan, and drops all the way to 1.8e20 in USN. Te,ped stays up at 400--600eV during USN phase. Positive SSEP has a favorable effect on Prad. Next: Accelerate scan in SSEP |
| Aug 21 2007 12:56:17:587PM | 1070821013 | Jerry Hughes | Plasma. Full length. 5.4T, 800kA.
Prf=3MW with one trip at 1.26s. SSEP~ -4mm at 1s, then scans to +7mm by 1.25s. Overshoots and returns to +6mm at end. ne,PED~2.4e20 at beginning of scan, and drops all the way to 1.8e20 in USN. Te,ped stays up at 400--600eV during USN phase. Positive SSEP continues to have a favorable effect on Prad. Lost DNB early. Next: Add a scan back down to -5mm from 1.25s to 1.5s |
| Aug 21 2007 12:19:54:080PM | 1070821014 | Jerry Hughes | Fizzle. |
| Aug 21 2007 12:48:14:920PM | 1070821015 | Jerry Hughes | Plasma. Full length. 5.4T, 800kA.
SSEP sweeps from -5mm to +5mm and back down again from 1.0 to 1.5s. RF is good. ne,PED~2.3e20 at beginning of scan, drops down to 1.7e20 then back up. Very cool. Next: Jog ZCUR up and down at 1.0s and 1.25s. |
| Aug 21 2007 01:02:09:927PM | 1070821016 | Jerry Hughes | Good H-mode while it lasts. SSEP ~ -5mm
The attempt to jog ZCUR instantaneously results in a disruption. |
| Aug 21 2007 01:10:32:627PM | 1070821017 | Jerry Hughes | Fashizzile |
| Aug 21 2007 01:36:36:510PM | 1070821018 | Jerry Hughes | Plasma. Full length. 5.4T, 800kA.
SSEP jogs from -6mm to +4mm over 1.00-->1.05s, then from +5mm to -4mm over 1.26-->1.30s Injection at 0.83s kills our H-mode, RF coupling temporarily. We have continuous H-mode through the 2nd jog. Next: Try again. |
| Aug 21 2007 01:39:02:090PM | 1070821019 | Jerry Hughes | Everything looks good up to and through the 1st jog, but the plasma goes
vertically unstable shortly after. Next: retry with jogs slowed from 50ms to 75ms. |
| Aug 21 2007 01:56:33:680PM | 1070821020 | Jerry Hughes | Full length shot, Bt=5.4T, 800kA
SSEP jogs from -5mm to +5mm and back at 1.0s and 1.25s, with H-mode maintained throughout. Interestingly, after the first jog, ~150ms pass before the pedestal density reaches its minimum. As we sweep back into LSN, ne,ped rises continuously through the sweep and after. Now there will be a cell access to attempt to open the z bolo shutter, and also for other diagnosticians to check on things. Next shot: SSEP flat at +5mm, then ramp down to -5mm over 1.25-->1.5s |
| Aug 21 2007 02:34:03:707PM | 1070821021 | Jerry Hughes | Full length shot, Bt=5.4T, 800kA
SSEP starts at +5mm, then scans down to -5mm from 1.25s to 1.5s. H-mode triggered at 0.83s with 3MW ICRF, but it is transient and ELM-free, probably because it's USN. ne,ped~2.2e20, Te,ped from >600eV to <400eV as Prad rises. Next: try to ramp SSEP down starting at 0.9s |
| Aug 21 2007 02:45:00:363PM | 1070821022 | Jerry Hughes | Full length shot, Bt=5.4T, 800kA
SSEP starts at +5mm, then scans down to -5mm from 0.9s to 1.15s. There is some funny business with SSEP from EFIT at 1.0s, but the reconstructions all look fine. The sweep appears to have arrested the radiated power rise, allowing us to maintain the H-mode through the sweep. ne,ped rises from 2.0 to 2.7e20 during the sweep, and Te,ped drops from ~600eV to ~300eV. Next: SSEP +2mm, with a ramp down to -5mm over 1.00s-->1.25s |
| Aug 21 2007 03:04:42:410PM | 1070821023 | Jerry Hughes | Full length shot, Bt=5.4T, 800kA
Fantastic RF pulse, 3MW flat from 0.8 to 1.5s. SSEP starts at +2--3mm, then scans down to -6mm from 1.0s to 1.25s. At this starting condition, the radiated power actually seems under control, before the SSEP scan begins. The pedestal is pretty steady. ne,ped rises from 2.0 to 2.6e20 during the sweep, and Te,ped drops from ~500eV to ~300eV. Next: Delay ramp down to begin at 1.25; see how long this steady H-mode can be maintained. |
| Aug 21 2007 03:25:58:863PM | 1070821024 | Jerry Hughes | Full length shot, Bt=5.4T, 800kA
Good RF pulse, 3MW from 0.8 to 1.5s, with 3 faults in J-port. SSEP is ~+3mm, then scans down to -8mm from 1.25s to 1.5s. Radiated power stays low in the USN phase, but strangely, Te,ped is only ~400eV! H-mode is very steady. ne,ped rises from 2.0 to 2.6e20 during the sweep Next: Try to start with SSEP=0 |
| Aug 21 2007 03:44:22:283PM | 1070821025 | Jerry Hughes | Full length shot, Bt=5.4T, 800kA
Good RF pulse, 3MW from 0.8 to 1.46s. SSEP is close to 0mm, slightly negative, then scans down to -7mm from 1.25s to 1.5s. More radiated power early, with a density rise during the DN phase. Next: Raise SSEP program by about 1mm. |
| Aug 21 2007 03:47:30:007PM | 1070821026 | Jerry Hughes | Full length shot, Bt=5.4T, 800kA
Good RF pulse, 3MW from 0.8 to 1.44s. SSEP is close to 0mm. It is slightly positive at the beginning of the H-mode, which seems to lower the initial H-mode density and the radiated power rise. The plasma appears to be extremely sensitive to changes in SSEP between 0mm and 2mm. Next: Scan to USN instead of LSN. |
| Aug 21 2007 03:58:07:913PM | 1070821027 | Jerry Hughes | Full length shot, Bt=5.4T, 800kA
Good RF pulse, 3MW from 0.8 to 1.5s with a couple of trips. SSEP is close to 0mm, slightly positive, then scans to +5mm from 1.25s to 1.5s. Radiated power is really taking off, unfortunately, dropping considerably the Te,PED. Going USN drops the density, and appears to stabilize the Prad somewhat. Next: Start at SSEP of -2mm |
| Aug 21 2007 04:14:49:520PM | 1070821028 | Jerry Hughes | Full length shot, Bt=5.4T, 800kA
Good RF pulse, 3MW from 0.8 to 1.5s with one trip. SSEP is between 0mm and -2mm in the early phase, then scans to +3--5mm from 1.25s to 1.5s. Again, a great deal of radiation early. Again, going USN drops the density. Next: Reprise shot 12 for comparison. Start LSN and ramp to USN. |
| Aug 21 2007 04:30:25:447PM | 1070821029 | Jerry Hughes | This was a repeat of shot 12. Prad about 3x faster in the H-mode now.
H89 is 1.0, instead of 1.8. I think this boronization is officially done. Next: Reload shot 24 (SSEP ~ +2mm) and keep ZCUR program flat. Yijun is going to put in an RF power ramp. |
| Aug 21 2007 04:45:48:863PM | 1070821030 | Jerry Hughes | A retry of shot 24, which has SSEP ~ +2mm. The initial phase of the H-mode
was more radiative this time around. Is it because the impurities or worse, or because we hit it with too much RF early? There is a promising phase of this discharge from 1.2s to 1.3s, which looks a lot like the steady H-mode of shot 24. For next shot, have Yijun put in 3MW flat until about 1s, and then he can ramp to whatever he wants. |
| Aug 21 2007 04:52:48:357PM | 1070821031 | Jerry Hughes | Again, a retry of shot 24, which has SSEP ~ +2--3mm.
The initial H-mode was still radiative, but ultimately we settled down into some kind of stationary (or dithering) H-mode. Next: run an Ohmic shot with a SSEP scan, watch the pressures in the upper and lower chambers. |
| Physics Operator Comments | |||
| Aug 21 2007 07:56:03:737AM | Robert Granetz | We go 79 psi of diborane used up in last night's boronization, despite the problems witht the RSView crash. | |
| Aug 21 2007 08:01:39:387AM | Robert Granetz | Loaded from shot 1070803008 (seg 4 active). Loaded seg 1 from 1070808001 (most recent post-boronization startup shot) Raised Ip to 0.80 MA Changed nl_04 to 0.8e20 m-2 for t=0.3 to 1.5 s. Set ZCUR at -0.01 m for entire flattop (to keep SSEP near -5 mm) Moved CLEARIN reference switch out to t = +3.0 s (will need this later in the run, but not for the first shots, which won't be swept). Loaded into model. Ready to go. Will probably do a no-power shot first to check the TF scanner. | |
| Aug 21 2007 09:22:04:730AM | 1070821002 | Robert Granetz | Shot 01 -- no-power TF scanner test |
| Aug 21 2007 09:29:18:333AM | 1070821002 | Robert Granetz | Shot 02 -- Plasma. Good shot. H-mode. RF sputtered ineffectively. SSEP turned out to be -3 mm. DNB fired okay. Next shot: Move ZCUR down by 2 mm (I don't know the exact relationship between ZCUR and SSEP, but this will help tell me.) |
| Aug 21 2007 09:44:30:687AM | 1070821003 | Robert Granetz | Shot 03 -- Plasma. Good shot. Looks like an incredibly steady, 1 second long H-mode. D-port RF worked well, E-port is improving. DNB is up to 5 amps. SSEP is about -4 mm. Inner gap is 1.2 cm, and pretty constant. Next shot: Reduce ZCUR another 2 mm, which should decrease SSEP by 1 mm, based upon the result from shot 03. |
| Aug 21 2007 09:57:24:680AM | 1070821004 | Robert Granetz | Shot 04 -- Plasma. Good shot. Disrupted during current rampdown...looks like an injection. SSEP is -5 mm, and constant. Next shot: tweak Ip and Ip gain to get current up to flattop value a little earlier. |
| Aug 21 2007 10:15:00:580AM | 1070821005 | Robert Granetz | Shot 05 -- Plasma. Good shot. D and E are operating very nicely. J is improving. Next shot: no DPCS changes. NINJA puff will be turned off for this shot to see if if changes the fueling. |
| Aug 21 2007 10:20:28:570AM | 1070821006 | Robert Granetz | Shot 06 -- Plasma. Disrupted at t=0.71 s. Several injections. Next shot: try again, no DPCS changes. |
| Aug 21 2007 10:42:25:553AM | 1070821007 | Robert Granetz | Shot 07 -- Fizzle. Post-disruption recovery? Next shot: no changes...leave the pre-fill as is. |
| Aug 21 2007 10:57:47:937AM | 1070821008 | Robert Granetz | Shot 08 -- Plasma. Good shot. Prf=3 MW total Next shot: ramp SSEP from -5 to +5 mm from t=1.0 to 1.5 s. This will be accomplished by sweeping ZCUR from -14 to +3 mm. |
| Aug 21 2007 11:11:15:707AM | 1070821009 | Robert Granetz | Shot 09 -- Plasma. Good shot. SSEP scanned from -5 to +3 mm. Disrupted at t=1.54 s, possibly because I didn't let the CLEARIN reference change. There was a big injection around 0.7 s. Next shot: Turn on CLEARIN reference switch at t=1.3 s. Increase ZCUR ramp upper limit to +6 mm. Decrease pre-fill by 3 ms to try avoiding a post-disruption fizzle. |
| Aug 21 2007 11:29:44:830AM | 1070821010 | Robert Granetz | Shot 10 -- Plasma. Good shot. SSEP ramped from -6 to +4 mm. A number of diagnostic gate valves closed during the shot, cutting off signals for GPC, TCI (late), Thomson, and maybe the DNB. PLC problem w/TORVAC? Next shot: increase pre-fill by 2 ms; Add +2 mm offset to ZCUR programming. |
| Aug 21 2007 11:39:11:343AM | 1070821011 | Robert Granetz | Shot 11 -- Fizzle. Why? Next shot: decrease pre-fill by 2 ms just to do something |
| Aug 21 2007 12:00:27:893PM | 1070821012 | Robert Granetz | Shot 12 -- Plasma. Good shot. SSEP scanned from -4 to +6 mm. Prf=3 MW. Next shot: Do the ZCUR (SSEP) ramp more rapidly. It will now ramp from 1.0 to 1.25 s (instead of 1.5 s). Also move CLEARIN switch earlier (to 1.15 s). |
| Aug 21 2007 12:16:01:090PM | 1070821013 | Robert Granetz | Shot 13 -- Plasma. Good shot. SSEP scanned from -4 to +7 mm over the shortened time range. Prf=3 MW. Next shot: program ZCUR to ramp back down from t=1.25 to 1.5 s. Also, add -2 mm offset to ZCUR programming. |
| Aug 21 2007 12:20:23:173PM | 1070821014 | Robert Granetz | Shot 14 -- Fizzle. Next shot: reduce pre-fill another 2 ms. |
| Aug 21 2007 12:47:00:870PM | 1070821015 | Robert Granetz | Shot 15 -- Plasma. Good shot. Good SSEP scan back and forth. Torus pressure and nitrogen on RGA are rising. Next shot: Program ZCUR with an ""instantaneous"" jump from previous min to max and back again. Also turn on B-side-lower (50 ms, argon) |
| Aug 21 2007 12:56:21:637PM | 1070821016 | Robert Granetz | Shot 16 -- Plasma. Disrupted at t=1.03, maybe due to the sudden jump programmed in ZCUR. Plasma went vertically unstable. Next shot: Slow down the ZCUR jump to 50 ms, rather than 1 ms. Also decrease pre-fill puff by 2 ms to try avoiding a post-disruption fizzle. |
| Aug 21 2007 01:10:02:937PM | 1070821017 | Robert Granetz | Shot 17 -- Fizzle. Next shot: decrease pre-fill another 1 ms, just to do something. |
| Aug 21 2007 01:23:45:910PM | 1070821018 | Robert Granetz | Shot 18 -- Plasma. Good shot. Good SSEP jogs up and back. Next shot: add the 1 ms back to pre-fill puff. Repeat this shot for RF. |
| Aug 21 2007 03:43:13:530PM | 1070821019 | Robert Granetz | Shot 19 -- Plasma. Disrupted at t=1.11 s due to vertical instability. Next shot: slow ZCUR jog slightly to 75 ms (from 50 ms). Also subtract 1 ms from pre-fill puff. Lithium pellet will be fired at t=1.7 s. |
| Aug 21 2007 02:15:45:147PM | 1070821020 | Robert Granetz | Shot 20 -- Plasma. Good shot. Very good SSEP scan. Lithium pellet fired at t=1.7 s. There will be a cell access now for a few miscellaneous minor things. Next shot: Start with upper null (ZCUR at its upper limit) until t=1.25, and then ramp down to its lower limit at t=1.5 s. Also switch CLEARIN reference appropriately. Increase pre-fill by 1 ms. |
| Aug 21 2007 02:29:44:700PM | 1070821021 | Robert Granetz | Shot 21 -- Plasma. Good shot. Upper null until t=1.4 s, then lower null. Next shot: start ZCUR ramp back to lower null at t=0.9 s (instead of 1.25 s), and have it reach the lower limit at t=1.15 s. Adjust CLEARIN reference switch accordingly. |
| Aug 21 2007 02:48:49:340PM | 1070821022 | Robert Granetz | Shot 22 -- Plasma. Good shot. Good ZCUR/SSEP scan. Good 3 MW RF. Next shot: Change ZCUR/SSEP programming slightly. Will be barely upper null, then switch to solid lower null. Change CLEARIN reference switch appropriately. |
| Aug 21 2007 03:05:23:427PM | 1070821023 | Robert Granetz | Shot 23 -- Plasma. Good shot. Good ZCUR/SSEP scan. Good 3 MW RF. Next shot: delay transition back to lower null to t=1.25-1.50 s. Delay CLEARIN reference switch accordingly. |
| Aug 21 2007 03:17:32:883PM | 1070821024 | Robert Granetz | Shot 24 -- Plasma. Good shot. Good ZCUR/SSEP scan. Good 3 MW RF. Next shot: Change ZCUR/SSEP programming to give SSEP of 0 mm until t=1.25 s, then switch to lower null. |
| Aug 21 2007 03:29:24:040PM | 1070821025 | Robert Granetz | Shot 25 -- Plasma. Good shot. Good ZCUR/SSEP program. Good 3 MW RF. Next shot: move SSEP by 1 mm (ZCUR up by 1.5 mm). |
| Aug 21 2007 03:45:27:083PM | 1070821026 | Robert Granetz | Shot 26 -- Plasma. Good shot. Good ZCUR/SSEP programming. Good 3 MW RF. Next shot: Start with same ZCUR/SSEP (0 mm) and ramp ZCUR/SSEP up. |
| Aug 21 2007 03:59:42:807PM | 1070821027 | Robert Granetz | Shot 27 -- Plasma. Good shot. Good ZCUR/SSEP programming. Good 3 MW RF. Next shot: Start with ZCUR/SSEP slightly lower null, then ramp to upper null. Adjust CLEARIN reference switch accordingly. |
| Aug 21 2007 04:15:13:863PM | 1070821028 | Robert Granetz | Shot 28 -- Plasma. Good shot. Good ZCUR/SSEP programming. Good 3 MA RF. Next shot: repeat shot 12 (load seg 4 from seg 4 of 1070821012). This shot started in lower null and ramped slowly to upper null. |
| Aug 21 2007 04:29:13:460PM | 1070821029 | Robert Granetz | Shot 29 -- Plasma. Good shot. Good ZCUR/SSEP programming. Good 3 MW RF. Disrupted late in rampdown due to lithium pellet injection. Next shot: import seg 4 from shot 24 into seg 4, but remove the ramp to lower null. Also adjust CLEARIN reference accordingly. |
| Aug 21 2007 04:39:15:383PM | 1070821030 | Robert Granetz | Shot 30 -- Plasma. Good shot. Good ZCUR/SSEP programming. RF tried for 4 MW, but there was a lot of faulting on J, so the total power varied between 2 and 4 MW. Next shot: repeat for the RF; no DPCS changes |
| Aug 21 2007 04:51:16:963PM | 1070821031 | Robert Granetz | Shot 31 -- Plasma. Good shot. Good ZCUR/SSEP programming. J-port faulted multiple times while trying to get total ICRF power up to 4 MW. Next shot: load seg 4 shot 10 into seg 4 and change the ZCUR/SSEP timing to start ramp at t=0.5 s. Also change CLEARIN reference switch accordingly. This shot will be ohmic. |
| Aug 21 2007 05:04:46:297PM | 1070821032 | Robert Granetz | Shot 32 -- Plasma, but disrupted at t=0.07 s when Ip=280 kA. Nothing obvious. End of run. |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 08:20:38:480AM | Test | Ok | TF scanner |
| 2 | 09:17:48:097AM | Plasma | Ok | |
| 3 | 09:32:51:590AM | Plasma | Ok | |
| 4 | 09:46:00:203AM | Plasma | Ok | |
| 5 | 10:01:38:053AM | Plasma | Ok | |
| 6 | 10:17:14:910AM | Plasma | Ok | |
| 7 | 10:31:28:693AM | Plasma | Ok | |
| 8 | 10:45:16:153AM | Plasma | Ok | |
| 9 | 11:01:10:677AM | Plasma | Ok | |
| 10 | 11:15:20:073AM | Plasma | Ok | |
| 11 | 11:35:23:153AM | Plasma | Ok | |
| 12 | 11:48:08:577AM | Plasma | Ok | |
| 13 | 12:01:09:677PM | Plasma | Ok | |
| 14 | 12:17:27:607PM | Plasma | Ok | |
| 15 | 12:30:36:550PM | Plasma | Ok | |
| 16 | 12:47:49:763PM | Plasma | Ok | |
| 17 | 01:03:19:397PM | Plasma | Ok | |
| 18 | 01:16:07:307PM | Plasma | Ok | |
| 19 | 01:28:52:827PM | Plasma | Ok | |
| 20 | 01:41:40:407PM | Plasma | Ok | |
| 21 | 02:18:46:073PM | Plasma | Ok | |
| 22 | 02:32:19:093PM | Plasma | Ok | |
| 23 | 02:51:10:030PM | Plasma | Ok | |
| 24 | 03:04:19:613PM | Plasma | Ok | |
| 25 | 03:18:37:370PM | Plasma | Ok | |
| 26 | 03:31:43:327PM | Plasma | Ok | |
| 27 | 03:47:39:837PM | Plasma | Ok | |
| 28 | 04:01:47:450PM | Plasma | Ok | |
| 29 | 04:16:29:800PM | Plasma | Ok | |
| 30 | 04:30:41:137PM | Plasma | Ok | |
| 31 | 04:44:25:080PM | Plasma | Ok | |
| 32 | 04:59:11:303PM | Plasma | Ok | |
| System Availability | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Aug 21 2007 08:20:13:603AM | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||