| Miniproposals | ||||||||||
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| Operators | |
| Session leader(s): | Steve Wolfe,Jerry Hughes |
| Physics operator(s): | Jim Irby |
| Engineering operator(s): | Bill Cochran,Bill Parkin,Ed Fitzgerald |
| Engineering Operator Run Comment |
| MP#645a Scoping study of N2 seeding in high current |
| Session Leader Plans |
| Entered: Aug 6 2012 11:54:08:850AM |
| Author: Steve Wolfe |
Session Leader Plan for Tuesday, Aug 7, 2012 09:00 to 13:00
MP#645a Scoping study of N2 seeding in high current
ITER-like EDA discharges
SL: wolfe
PO: Irby
The goal of this run is to develop N2 seeding suitable for use with
high power ITER-like discharges at 1.3MA, 5.4T at maximum available
RF power. We will be using the divertor-localized seeding lines,
principally the B-DIV piezovalve, which puffs into a closed divertor
port. Note that this valve uses the H-BOT Plenum, which should be
filled to 16psi of N2.
Suggested gas setup:
Require N2 bottle connected
Pump and purge all plenums (except B-side Upper)
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 H-bot with 16psi of N2, Hybrid DISABLED (PG5)
fill NINJA with 10 psi D2 DISABLED
Shot sequence
--------------
1) Start from the reference shot 1120801002, using both segment 1 and 2 as
specified (note early crowbar, IP control in seg1, early seg switch).
Change PG3 in seg1 to 100V from -.02 to -.016, 30V at -.014 to +.015,
then zero.
In seg2, raise to nl04=1.4e20 target, to promote EDA. Move end of rampdown to 1.7sec.
Begin RF pulse at t=0.6sec, flat at 2MW to EOF at 1.2sec, extend at 1MW into rampdown.
Establish EDA discharge, unseeded operation, strikepoint locations,
diagnostic coverage. Recover from boronization as quickly as possible.
[1-3 shots]
2) Increase RF power to ramp from 2.5MW to 3.5MW between 0.6 and 1.2sec.
a. Evaluate with no seeding, increase nl04 target if necessary to enhance
EDA [1-2 shots]
b. Puff N2 from B-DIV piezo (PG6) at 20% duty factor from
t=0.55 to 1.0sec. Observe usual signatures, with emphasis on core Mo,
core N, Prad, Pnet. Also monitor divertor probes for detachment [1 shot]
c. Increase N2 puff level to 40% [1 shot]
d. Keep increasing puff level until it is obviously too high (60,80,100%?)
[2-3 shots]
3) Increase RF power to reach 4.5MW (or higher) at end of ramp. Adjust puff
level, waveform [3 shots]
4) If time remains, run modulated N2 puff at 10 Hz from 0.5 sec to EOF
(t=1.2sec). Use either 100% amplitude or twice the amplitude of best
seeding condition from step 2 or 3, whichever is less. Observe dynamic
response. Depending on result, try longer or shorter period. [2 shots]
Note to physop: Use Modulate switch on ALL_V's popup menu.
|
| Entered: Aug 6 2012 08:50:36:670PM |
| Author: Jerry Hughes |
| PM run: MP715 (0.5 days)
Will get hand-off from MP645a around 13:00. Make sure that ECE, D-alpha, and bolometry are all in working order. We will also want to monitor N content and neutral pressure. Disable NINJA. Enable Ar from B-side lower. Use a 50ms puff at 0.3s. Keep this constant throughout the run. (1) Load from 1120711021. Set nl04 = 8.5e19. Set Ip = 0.93 MA. Increase ZCUR so that elongation increases to 1.7--1.75, SSEP becomes ~ -1cm. This will improve edge Thomson coverage and also provide a more ITER-like shape. Apply constant 1.0MW of ICRF from 0.5 to 1.5s. Tweak Bt as needed in order to optimize ECE positioning near psi95. If no H-mode, increment power by 0.2MW in each successive shot until L-H occurs. Then decrement by 0.1MW in each successive shot until no L-H is observed. If there is an H-mode, then decrement power by 0.2MW in each successive shot until no L-H is observed. Then increment 0.1MW in each successive shot until L-H is observed again. (2) Increase initial flattop value of Ip to 1.1MA (by 0.5s). Ramp Ip from 1.1MA to 0.8MA over 0.7s to 0.8s. Ramp Ip from 0.8MA to 1.1MA over 1.0s to 1.1s. Ramp Ip from 1.1MA to 0.8MA over 1.3s to 1.5s. (Note the final ramp-down phase is slower than the prvious one.) Pulse ICRF from 0.5 to 1.5s at a total power just below that needed to obtain H-mode in (1). Based on observations, either increment or decrement ICRF power in successive shots. If possible, obtain at least one case with no H-modes at lower power, and one case which stays in H-mode throughout most of the discharge at higher power. If, due to favorable hysteresis, H-mode is persistent, we may reduce the ICRF power following the H-mode formation. (3) Decrease initial flattop value of Ip to 0.8MA. Ramp Ip from 0.8MA to 1.1MA over 0.7s to 0.8s. Ramp Ip from 1.1MA to 0.8MA over 1.0s to 1.1s. Ramp Ip from 0.8MA to 1.1MA over 1.3s to 1.5s. (Note the final ramp-up phase is slower than the prvious one.) Pulse ICRF from 0.5 to 1.5s at a total power just below that needed to obtain H-mode in (2). Based on observations, and experience from (2), either increment or decrement ICRF power in successive shots. If possible, obtain at least one case with no H-modes at lower power, and one case which stays in H-mode throughout most of the discharge at higher power. If, due to favorable hysteresis, H-mode is persistent, we may reduce the ICRF power following the H-mode formation. |
| Physics Operators Plans |
| Entered: Aug 6 2012 12:13:11:023PM |
| Author: Jim Irby |
| -----------------
Engineering Setup ----------------- Run begins at 09:00 and ends at 17:00 First Half of Run ================= Power systems as on: 1120801002 Acoil: +Dtop -Dbot -Jtop +Jbot (standard) Hybrid Enabled Gas setup: Require N2 bottle connected Pump and purge all plenums (except B-side Upper) 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 H-bot with 16psi of N2, Hybrid DISABLED (PG5) fill NINJA with 10 psi D2 DISABLED Enable gate-valves and shutters: ECE, VUV, HiREX Sr, Xeus/LoWEUS Leave z-bolo shutter as is (should be open) Torvac gatevalve toggle (yes/no): no Boronization(yes/no): yes (completed on Sunday) Overnight ECDC (yes/no): Yes ICRF(yes/no): Yes LH(yes/no): no Cryopump (yes/no): no DNB (yes/no): no Vessel temperature: 35/35/35 ------------------------------ ECDC Parameters (if requested) ------------------------------ gas and pressure: D2 at 2e-4 Torr sweep: 44/45/103 cm scan: 20/120 s |
| Session Leader Summaries |
| Entered: Aug 7 2012 02:46:59:613PM |
| Author: Steve Wolfe |
Session leader summary for Tuesday, Aug 7, 2012 (Morning) MP#645a N2 seeding of ITER-like discharges SL: wolfe PO: Irby EO: Cochran, Parkin We managed to complete most of the main part of the run plan, getting through the high power rf (up to 4.5MW). Seeding seemed to be having a favorable effect in keeping the Mo levels low, except for injections, which continued to be a problem for much of the day. We also were getting Ti and Fe injections. We increased the target density to nl04~1.6e20 at the high power end, which seemed to improve the EDA-ness. H-mode nebar was over 5e20 (n/nG~0.6), and ECE cut-offs were observed on all channels; these should be useful for recalibrating the TS density, which needs it because the laser alignment was redone after the power outage yesterday. The RF struggled above 4MW, but we got a few good shots at that level with minmal dropouts. Stored energy was respectable, over 200kJ, but not up to record levels. H98 values were between .7 and .8. The maximum beta_N was only ~1.2, which is not in the target range for IOS-1.1. Pnet was just over 3MW. Low Z, mostly N, was replacing the Mo radiation, so there was not a big win in the core Prad. The best seeding seemed to be in the range of 40 to 60% puff rate, which corresponds to 9 to 13 Torr-l/sec for .45sec, with the N2 arriving just at the start of the RF pulse and continuing until 1 sec. We did not vary the pulse length in this experiment, and it may be that we could have done better by shutting the N2 off earlier. Zave from VB was ~1.7 in the unseeded case (#7) and ~2.1 to 2.3 with seeding. The best H-modes were those that started later in the RF, typically at slightly higher target density. In a few cases we were getting ohmic H-modes before the RF turned on, and these were essentially ELM-free with increasing Prad. Good shots for further examination include: 007 No seeding 2.5->3.5MW 1.4e20 target 008 20% seed 2.5->3.5MW 1.4e20 target 010 40% seed 2.5->3.5MW 1.4e20 target 011 60% seed 2.5->3.5MW 1.4e20 target 012 40% seed 2.5->3.5MW 1.5e20 target 014 40% seed 3.5->4.5MW 1.5e20 target 015 40% seed 3.5->4.5MW 1.5e20 target 016 40% seed 3.5->4.5MW 1.5e20 target 017 60% seed 3.5->4.5MW 1.5e20 target 018 40% seed 3.5->4.5MW 1.6e20 target The target plasmas were adapted from 1120801002. The initial shape had the strike point up on the outer plate around tile 4, and did not give an H-mode at 2MW until rampdown. A small tweak in RXL before shot 7 moved the strike down to the tile 2 or 3 region, and allowed early H-modes, including some ohmic transitions. This may not have been a good thing, but we did not change the strike again (intentionally) for the remainder of the experiment. The targer ramp-up also suffered from a vertical thrash around segment switch (.08sec). Several changes were tried to smooth out the transition, which resulted in disruptions on shots 9 and 13, with no success. Some post-mortem analysis will be necessary to figure out what is causing this problem. I suspect feedforward programming on the EF1's or EF2's. |
| Entered: Aug 7 2012 06:46:55:030PM |
| Author: Jerry Hughes |
| Since I was visiting GA this week, I led this session remotely from Rich
Groebner's office using videoconferencing tools and a remote login. Thanks, Rich! We had a good 1/2 day run in which I got through more or less the whole run plan. ICRF power scans were obtained in both a control discharge with no Ip ramps, and in a series of discharges in which current was ramped back and forth between 0.8MA and 1.1MA. There were some indications that the ramp-up phases might inhibit H-mode at a fixed amount of ICRF heating, and that the opposite might be true of ramp-downs. However, it will be necessary to carefully calculate the Ohmic power (beyond what shows up in my scopes) in order to properly evaluate the power thresholds, since Poh was the dominate term in Ptot for most of the shots today. |
| Entered: Aug 8 2012 08:52:35:813PM |
| Author: Jerry Hughes |
| Here is a possible run plan for a subsequent 1/2 day of MP715, building on
the experience of 1120807 . . . It is evident that we must raise the power threshold from ~1.5MW (where Ohmic power dominates) to something in the ballpark of 2--3MW. Therefore we will increase the target nl04 from 0.9e20 to 1.3e20. According to [Y. Ma, NF2012], this will place Pth at about 2.5MW, and now ~1.5MW will be required from ICRF. (1) Control discharge (no ramp): Load from 1120807021. Remove RCUR ramp; set RCUR to be constant 0.659m over entire flattop. Set nl04 to 1.3e20. Shot (1a): Find approximate threshold. Over 0.5s to 1.5s, ramp Prf from 1.0MW to 2.0MW. Note power at transition. Shot (1b): Choose Prf 200kW lower than the power determined from shot (1a). Apply constant ICRF at that level from 0.5 to 1.5s. Shots (1c): Increment/decrement power as needed in order to determine threshold power. (2) Introduce current ramps. Change the current demand so that: 0.5--0.7s: flat 0.8MA 0.7--0.8s: ramp from 0.8 to 1.1MA 0.8--1.0s: flat 1.1MA 1.0--1.1s: ramp from 1.1 to 0.8MA 1.1--1.3s: flat 0.8MA 1.3--1.5s: ramp from 0.8 to 1.1MA 1.5-- : ramp down as usual For the following shots, RF will be switched between 6 levels of power: P1 (low Ip), P2 (ramp-up), P3 (high Ip), P4 (ramp-down), and P5 (slow ramp-up). 0.5--0.7s: P1 0.7--0.8s: P2 0.8--1.0s: P3 1.0--1.1s: P4 1.1--1.3s: P1 1.3--1.5s: P5 Take the RF power required for H-mode access in (1). Call this P0. Shot (2a): Set P1=P2=P3=P4=P5= (P0 - 200kW) Run the shot. Look for L-H transitions. Shots (2b): Adjust the Px values shot-to-shot in order to resolve the power threshold in each phase. If H-mode is obtained in a given stage x, then reduce Px on the subsequent shot. If no H-mode is observed in a given ramping phase, then increase power in that phase on the subsequent shot. Try to avoid H-modes in the mini-flattops. (3) Change the order of current ramps to rule out time-sensitive behavior: Change the current demand so that: 0.5--0.7s: flat 1.1MA 0.7--0.8s: ramp from 1.1 to 0.8MA 0.8--1.0s: flat 0.8MA 1.0--1.1s: ramp from 0.8 to 1.1MA 1.1--1.3s: flat 1.1MA 1.3--1.5s: ramp from 1.1 to 0.8MA 1.5-- : ramp down as usual Now there will be a new ordering for the RF power demands: 0.5--0.7s: P3 0.7--0.8s: P4 0.8--1.0s: P1 1.0--1.1s: P2 1.1--1.3s: P3 1.3--1.5s: P6 Where P6 is the power in the slow ramp-down phase and replaces the P5 setting. Shot (3a): Leave P1--P4 at below threshold power as determined in Step (2). Set P6= (P0 - 200kW) Run the shot. Look for L-H transitions. Shots (3b): Adjust the Px values shot-to-shot in order to resolve the power threshold in each phase. If H-mode is obtained in a given stage x, then reduce Px on the subsequent shot. If no H-mode is observed in a given ramping phase, then increase power in that phase on the subsequent shot. Try to avoid H-modes in the mini-flattops. |
| Physics Operator Summaries |
| Entered: Aug 7 2012 05:40:04:753PM |
| Author: Jim Irby |
| The machine ran well today. We ran two different mini-proposals, mp645a
in the morning (shots 2 to 18), and mp715 in the afternoon (shots 19 to 33). Most of the plan was completed for both mini-proposals. For mp645a a vertical instability was present most of the day, occurring around 100 ms, which we were unable to tweak out and may have caused us to lose one plasma. Most changes during the morning involved adjustments to the nitrogen puff rates and a few nl04 tweaks to adjust the target for the h-modes. For mp715 we started from 1120711021 on shot 19. ZCUR was increased to increased the elongation from about 1.65 to 1.7 which improved the TS coverage. 300 kA ramps were programmed in the plasma current starting at shot 25. Ramp rates of 300kA/100mS and 300kA/200ms were successfully run. The control system handled these ramps easily. Shot 33 was a locked mode calibration shot (loaded from 1120720008) that ran successfully and provided a good HiRex cal. Test: 01 Plasma 02,03,05-19,21-33 Fizzle 04 --- followed disruption Problems: The EF1 supply did not commutate on shot 20. Waggle around segment switch may have lost us a shot or two. |
| Session Leader Comments | |||
| Aug 7 2012 08:24:55:997AM | 1120807001 | Steve Wolfe | Shot#1: Data system and gas test Seems to have run through ok. Gas plenum readings show up correctly B-side Upper 15.5psi He3 B-top 6.06psi D2 B-side Lower 0.81psi Ar B-Main 40.16psi D2 H-bottom 15.88psi N2 B-top and B-main enabled, total injected 1.3T-l. H-div MKS seems to have a problem, slow oscillation to 0.3T-l then back to zero. Shouldn't matter, since I don't plan to use it. |
| Aug 7 2012 09:15:10:527AM | 1120807002 | Steve Wolfe | Shot#2: First plasma attempt plasma full length. TV was off. Density is low early, need to increase programming Got an H-mode, RF E-port ran, J faulting, D tries but faults. Plasma is limited through rampup until 0.4sec, something is screwy. |
| Aug 7 2012 09:34:19:500AM | 1120807003 | Steve Wolfe | Shot#3: Raise nl04 target to 1.4 at 0.5sec Not sure why things are railed on shot#2, maybe just too much gas coming from wall. There was a marfe, hardly any gas from the valve. Result: disrupted at 1sec.Current rise looked better. It still re-contacts at crossover and near after 0.1, Only got E-port this time, D and J both faulting repeatedly. This one goes vertically, Chopper floors, not clear why. n/nc=1.1, Next: repeat. Hope |
| Aug 7 2012 09:42:22:473AM | 1120807004 | Steve Wolfe | Shot#4: Fizzle. not too surprising. Next: try again |
| Aug 7 2012 09:56:43:050AM | 1120807005 | Steve Wolfe | Shot#5: plasma full length One late H-mode, RF got to 2MW, but didn't get an H-mode until rampdown. Next: raise RF- start at 2.5, ramp to 3.5MW |
| Aug 7 2012 10:14:11:470AM | 1120807006 | Steve Wolfe | Shot#6: raise RF- start at 2.5, ramp to 3.5MW Want to lower the strike point a little, it was on tile4, Move rxl in by 6mm. Result: plasma, got H-modes but first one didn't last. disrupted in rampdown. D&E stay on ok, J faults Next: RF will tune up J, promises it will be better |
| Aug 7 2012 10:27:12:293AM | 1120807007 | Steve Wolfe | Shot#7: RF will tune up J, promises it will be better reduce argon, per Matt. Xeus still not back on the air after the overpressure from the disruption on 3. Result: plasma with an eda, still has an early elm free Got to 200kJ at 1.2sec Next: Put in some N2 |
| Aug 7 2012 10:45:43:820AM | 1120807008 | Steve Wolfe | Shot#8: Put in some N2, 20% on B-div from .55 to 1.0sec Xeus should be ready for this shot. Plasma 2 h-modes, looks similar. First h-mode is delayed, has a Mo injection. Looks like less neuts. 2nd H-mode still ends up at 200kJ Got some N2, 1.6T-l. Xeus confirms there is N. Next: go to 40% N2 and turn off the argon (Matt says they've got their alignment) |
| Aug 7 2012 11:04:48:077AM | 1120807009 | Steve Wolfe | Shot#9: go to 40% N2 and turn off the argon (Matt says they've got their alignment) Result: early disruption, .18sec, vertical thrash. Thrashing starts at seg switch, but it didn't do that on shot#8 or any of the earlier ones. |
| Aug 7 2012 11:19:38:003AM | 1120807010 | Steve Wolfe | Shot#10: repeat, going to 40% N2 and turn off the argon (Matt says they've got their alignment) Result: plasma, 3 h-modes, last one is EDA-ish Mo injections (?) in first two. Got to 220kJ at end of EOF, more neuts. ECE is cutting off. Got 3.5T-l of N2 in. This is not obviously an improvement. Pnet=3MW, H98=0.8 at EOF next: go to 60% on N2 |
| Aug 7 2012 11:29:03:920AM | 1120807011 | Steve Wolfe | Shot#11: go to 60% on N2 plasma still multiple H-modes. May be getting worse. Prad is up. Neuts are down. Next: Raise nl04 to 1.5e20, drop N2 to 40% |
| Aug 7 2012 11:40:10:463AM | 1120807012 | Steve Wolfe | Shot#12: Raise nl04 to 1.5e20, drop N2 to 40% Going off script a bit, try to recover the EDA-ness before raising the power. plasma, one later H-mode with an injection at EOF Wmhd=219kJ at 1sec, 2pi diode below 2MW. Next: raise RF to 4.5MW at EOF, starting from 3MW |
| Aug 7 2012 11:59:39:863AM | 1120807013 | Steve Wolfe | Shot#13: raise RF to 4.5MW at EOF, starting from 3MW leave nl04 and B-div for now. Another shorty. Vertical thrash at seg switch. Shot#12 almost lost it the same way. |
| Aug 7 2012 12:15:48:237PM | 1120807014 | Steve Wolfe | Shot#14: raise RF to 4.5MW at EOF, starting from 3MW leave nl04 and B-div for now. plasma, 2 h-modes, first one gets to ~220kJ, but looks ELM-free, starting to radiate away. RF gets to 4, with D struggling Readjust the balance Next: Delay integrator A gate to 0.1sec, match Zcur waveforms across seg switch, trying to eliminate thrash |
| Aug 7 2012 12:28:27:173PM | 1120807015 | Steve Wolfe | Shot#15: Readjust the balance of RF Delay integrator A gate to 0.1sec, match Zcur waveforms across seg switch, trying to eliminate thrash plasma similar 2 h-modes, second one is better, 215kJ, but radiating. RF still faulting at end of pulse, J this time. Next: Raise N2 puff to 60%, tweak ZCUR3 Pgain to delay switch to 0.1sec |
| Aug 7 2012 12:47:59:770PM | 1120807016 | Steve Wolfe | Shot#16: Raise N2 puff to 60% from 40%, tweak ZCUR3 Pgain to delay switch to 0.1sec plasma first H-mode is more eda'ish, injection near 1sec, drops out of H-mode at 1.08sec B-div change didn't get made, it's still at 40 Next: Go to 60 on B-div this time. |
| Aug 7 2012 01:01:49:257PM | 1120807017 | Steve Wolfe | Shot#17 Go to 60 on B-div this time. 2 H-modes, look mostly ELM-free D-port still faulting. Second H-mode gets to 220kJ Next: raise nl04 to 1.6e20. N2 back to 40 |
| Aug 7 2012 01:10:19:197PM | 1120807018 | Steve Wolfe | Shot#18: raise nl04 to 1.6e20. N2 back to 40 plasma still with injections, Ti and Fe second H-mode looks pretty good, 223kJ RF looks fairly clean Turning over to Jerry for the second half. |
| Aug 7 2012 02:06:46:013PM | 1120807019 | Jerry Hughes | Starting MP715.
First shot will be a control case without Ipdot, 1MW of ICRF. Result: 3 H-modes, first one at t=0.63s, about 130ms after ICRF turn-on. ECE coverage looks to be slightly inside psi95. Picrf = 1.1MW Ptot @L-H = 1.9MW P/Pth = 1.2--1.3 Next: Have PO raise TF by 1% to optimize ECE positioning. Lower Picrf to 800kW. |
| Aug 7 2012 01:44:18:520PM | 1120807020 | Jerry Hughes | Shot 20.
Attempt 5.5T, 0.93MA shot with 800kW ICRF. Result: Plasma fail. No EF1. Next: Retry. Up Ar B-side lower demand to 70ms. |
| Aug 7 2012 02:07:28:160PM | 1120807021 | Jerry Hughes | Shot 21
5.47T, 0.94MA, nl04=9.5e19 Result: 2 H-modes, first one at t=0.73s, about 230ms after ICRF turn-on. ECE coverage seems acceptable, although Amanda may be able to evaluate better Picrf = 0.9MW Ptot @L-H = 1.7MW P/Pth = 1.1--1.2 Next: Reduce Picrf another 200kW. |
| Aug 7 2012 02:20:57:437PM | 1120807022 | Jerry Hughes | Shot 22.
Same as previous shot, but with reduced Picrf. Result: 2 H-modes again, first one at t=0.74s, about 240ms after ICRF turn-on. Picrf = 0.7MW Ptot @L-H = 1.5MW P/Pth = 1.0 Next: Reduce starting Picrf another 300kW. Then at 1.3, reduce Picrf an additional 200kW. If it's in H-mode at that time, we might be able to get a read on P_H-L. |
| Aug 7 2012 02:34:13:277PM | 1120807023 | Jerry Hughes | Shot 23.
Same as previous shot, but with reduced Picrf. Result: 1 H-modes this time, making final transition at 1.12s, about 620ms after ICRF turn-on. There are what appear to be dithers before the transition. Picrf = 0.4MW Ptot @L-H = 1.2MW P/Pth = 0.8--1.0 Prf drops to 150kW late in the H-mode phase. Stays in H-mode at P/Pth~0.73 Also stays in H-mode during ramp-down. Next: another reduction of 200kW. Hold steady from 0.5 to 1.5s |
| Aug 7 2012 02:47:20:023PM | 1120807024 | Jerry Hughes | Shot 24.
Same as previous shot, only with constant 250kW ICRF Long dithering phase, with an injection at 1.35 that momentarily brings down the edge Te. Dithers return following this and there is an L-H at 1.45s. Picrf = 0.25MW Ptot @L-H = 1.3MW P/Pth = 0.8--0.9 I am inclined to say we've found the threshold power. Next: Put in some Ip ramps. Shot plan says we should operate at a power below the Pth from the control case. So, we will turn off ICRF on the first Ip ramping shot |
| Aug 7 2012 03:12:48:430PM | 1120807025 | Jerry Hughes | Shot 25.
First shot with Ip ramps. The ramps run as programmed. Ohmic only. No H-mode in the first fast ramp-down, although there may be some dithers at the end of it. Nothing like that in the quick ramp-up. The slower ramp-down at the end gives rise to an L-H at 1.37s: Picrf = 0 Ptot @L-H = 1.5MW P/Pth = 1.0 Ip = 1.0MA dIp/dt = -1.5MA/s Next: repeat with 250kW of ICRF |
| Aug 7 2012 03:39:05:407PM | 1120807026 | Jerry Hughes | Shot 26.
Multiple H-modes triggered now, with ICRF at 250kW. One in ramp-down: Ptot = 2.1MW P/Pth = 1.3 Ip = 0.99MA dIp/dt ~ -3 MA/s One in ramp-up: Ptot = 1.0 MW P/Pth = 0.3 Ip = 0.85MA dIp/dt ~ +3 MA/s And another in flat top: Ptot = 1.5 MW P/Pth = 0.9 Ip = 1.1MA dIp/dt ~ 0 The variation in Ptot here is dominated by the estimate of Poh. This is going to be sensitive to the time resolution of the EFIT in my scope. Note I have not subtracted off Wdot. |
| Aug 7 2012 03:33:31:440PM | 1120807027 | Jerry Hughes | My skype connection has been dropped.
It claims Matt is offline. |
| Aug 7 2012 03:44:33:600PM | 1120807027 | Jerry Hughes | Shot 27.
Similar to previous shot, but with 150kW ICRF. Result: Looks very similar in terms of H-mode timing. Again it will be critical to calculate the ohmic power correctly in order to make sense of the results. |
| Aug 7 2012 04:34:00:110PM | 1120807028 | Jerry Hughes | Shot 28.
First case starting at low Ip and ramping up. Picrf=150kW Clear L-H in the flattop phase at 0.93s. Ptot= 1.3MW P/Pth= 0.8 Ip= 1.10 dIp/dt ~ 0 |
| Aug 7 2012 04:36:28:883PM | 1120807029 | Jerry Hughes |
Shot 29. Same as previous shot, but with Picrf=350--400kW Multiple H-modes, but still not one in the initial ramp-up. |
| Aug 7 2012 04:38:15:090PM | 1120807030 | Jerry Hughes | Shot 30
Same as previous shot, but with Picrf=600kW. Still no H-mode in ramp-up. Get it in mini-flattop, the an H-L that causes control to be lost. Next: More power, changes Ip traces somewhat. |
| Aug 7 2012 04:28:42:593PM | 1120807031 | Jerry Hughes | Shot 31
For this shot, delay the ramp-down phase from [1.0,1.1]s to [1.2,1.3]s. Change RF program: 800kW from 0.5s to 0.9s, then 400kW from 0.9s to 1.1s, then 800kW from 1.1 to 1.5s |
| Aug 7 2012 04:49:37:550PM | 1120807031 | Jerry Hughes |
Shot 31. Same as previous shot, but with Picrf of ~800kW L-H occurs during the flattop phase, promptly after ICRF turned on. For same level of auxiliary heating, the ramp-up phase clearly does not transition. More H-modes in the longer flattop phase. Final ramp-up may induce a H-L. |
| Aug 7 2012 04:58:01:053PM | 1120807032 | Jerry Hughes | Shot 32.
Would like to keep the initial flattop phase out of H-mode, then hit the the ramp-up with more power. So keeping Ip trace the same, change RF demand: 0.50--0.65s: Hold at 400kW 0.65--0.70s: ramp from 0.4MW to 1.2kW 0.70--0.90s: hold at 1.2kW 0.90--1.50s: constant 400kW Result: Ramped up the power too soon, because the dithering and L-H occur slightly before the current ramp. Stays in H-mode during the ramp-up. Multiple L-H during the mini-flattop. Ramp-down at the end stays in H-mode until the disruption, despite having a low-ish Ptot. |
| Aug 7 2012 05:55:43:030PM | 1120807033 | Jerry Hughes | Shot 33.
Attempt a locked-mode calibration shot for HirexSr Looks good. |
| Physics Operator Comments | |||
| Aug 7 2012 08:24:14:900AM | Jim Irby | load from 1120801002
pg3 100 V from -0.02 to -0.016 s, 30 V from -0.014 to +0.015 s, then zero. nl04 from 1.0 to 1.4 e20 /m^2 Ip end-of-rampdown from 2.0 to 1.7 s (rampdown starts at 1.2 s) CLEARIN pulled negative by 1.7 s (from nearly 2 s). RCUR moved in more quickly starting at 1.2 s Open tree done | |
| Aug 7 2012 08:46:14:720AM | Jim Irby | pg1 from 0.3 to 0.35 s
Otd | |
| Aug 7 2012 09:07:51:800AM | 1120807002 | Jim Irby | changes --------------------------------
results -------------------------------- plasma into rampdown --- density too low early |
| Aug 7 2012 09:25:32:403AM | 1120807003 | Jim Irby | changes --------------------------------
nl04 to 1.4e20 /m^2 by 0.5 s from 1.0 s Otd results -------------------------------- disruption at 1.02 s density ok |
| Aug 7 2012 09:38:40:570AM | 1120807004 | Jim Irby | changes --------------------------------
prepuff from 25 to 20 ms --- compensate for disruption Otd results -------------------------------- fizzle |
| Aug 7 2012 10:01:04:843AM | 1120807005 | Jim Irby | changes --------------------------------
no PCS changes results -------------------------------- plasma into rampdown |
| Aug 7 2012 10:16:15:357AM | 1120807006 | Jim Irby | changes --------------------------------
RXL from +0.001 to -0.005 m Otd results -------------------------------- plasma into rampdown |
| Aug 7 2012 10:30:10:217AM | 1120807007 | Jim Irby | changes --------------------------------
pg1 puff reduced to 40 ms (300 to 340 ms) from 50 ms Otd results -------------------------------- plasma into rampdown |
| Aug 7 2012 10:41:40:977AM | 1120807008 | Jim Irby | changes --------------------------------
pg6 (B-DIV) at 20% from 0.55 to 1.0 s Otd results -------------------------------- plasma into rampdown |
| Aug 7 2012 11:04:01:303AM | 1120807009 | Jim Irby | changes --------------------------------
pg6 from 20 to 40% from 0.55 to 1.0 s Otd argon (b-side lower) is disabled results -------------------------------- plasma for 0.197 s --- 63 kA |
| Aug 7 2012 11:17:18:813AM | 1120807010 | Jim Irby | changes --------------------------------
try again --- no changes results -------------------------------- plasma into rampdown strong mhd on FTCI during H to L |
| Aug 7 2012 11:28:53:570AM | 1120807011 | Jim Irby | changes --------------------------------
pg6 from 40 to 60% Otd results -------------------------------- plasma into rampdown |
| Aug 7 2012 11:36:11:010AM | 1120807012 | Jim Irby | changes --------------------------------
nl04 request from 1.4 to 1.5e20 /m^2 pg6 from 60 to 40% Otd results -------------------------------- plasma into rampdown --- nice h-mode this time -- 219 kJ |
| Aug 7 2012 11:53:02:290AM | 1120807013 | Jim Irby | changes --------------------------------
no dpcs changes results -------------------------------- plasma for 133 ms -- vertically unstable |
| Aug 7 2012 12:04:38:737PM | 1120807014 | Jim Irby | changes --------------------------------
no dpcs changes results -------------------------------- plasma into rampdown |
| Aug 7 2012 12:23:59:570PM | 1120807015 | Jim Irby | changes --------------------------------
NINJA puffing D2 after 1.5 s try to improve startup z-waggle: Integrator A in seg2 start from 0.08 to 0.1 s ZUR in seg 1 and seg 2 zeroed before 0.1 s Otd results -------------------------------- plasma into rampdown --- still have waggle |
| Aug 7 2012 12:35:32:070PM | 1120807016 | Jim Irby | changes --------------------------------
pg6 back to 60% from 40% wire 3 seg 2 ZCUR prop gain at 0.0675 to 0.10 s Otd results -------------------------------- plasma into rampdown |
| Aug 7 2012 01:00:46:210PM | 1120807017 | Jim Irby | changes --------------------------------
pg6 from 40 to 60% ---- I did not make this change on shot 16 as intended. Otd results -------------------------------- plasma into rampdown --- 222 kJ |
| Aug 7 2012 01:10:30:167PM | 1120807018 | Jim Irby | changes --------------------------------
nl04 from 1.5 to 1.6e20 /m^2 pg6 from 60 to 40% Otd results -------------------------------- plasma into rampdown |
| Aug 7 2012 05:24:06:150PM | 1120807019 | Jim Irby | changes --------------------------------
switching to Jerry's mini --- N2 puffing disabled NINJA disabled Ar puffing enabled again from 0.3 to 0.35 s loaded from 1120711021 nl04 from 0.8 to 0.85e20 /m2 Ip from 800 to 930 kA ZCUR from -0.015 to -0.005 m Otd results -------------------------------- plasma into rampdown --- have good TS coverage, proper elongation, ssep |
| Aug 7 2012 01:41:47:397PM | 1120807020 | Jim Irby | changes --------------------------------
TF from 150.0 to 151.5 kA --- improve ECE coverage Otd results -------------------------------- ef1 commutation failure |
| Aug 7 2012 01:57:10:333PM | 1120807021 | Jim Irby | changes --------------------------------
argon from 50 to 70 ms (300 to 370 ms) Otd results -------------------------------- plasma into rampdown |
| Aug 7 2012 02:14:40:677PM | 1120807022 | Jim Irby | changes --------------------------------
no dpcs changes rf power change only results -------------------------------- plasma into rampdown |
| Aug 7 2012 02:25:44:230PM | 1120807023 | Jim Irby | changes --------------------------------
only rf changes results -------------------------------- plasma into rampdown |
| Aug 7 2012 02:56:49:463PM | 1120807024 | Jim Irby | changes --------------------------------
rf power change only results -------------------------------- plasma into rampdown --- late h-mode |
| Aug 7 2012 03:04:31:627PM | 1120807025 | Jim Irby | changes --------------------------------
no rf added ramps to Ip: 0.5 s 1.1 MA 0.7 to 0.8 s, 1.1 to 0.8 MA 1.0 to 1.2 s, 0.8 to 1.1 MA 1.3 to 1.5 s, 1.1 to 0.8 MA Otd results -------------------------------- plasma into rampdown --- Ip ramps look good Right gap getting small, around 2 mm, at 1.08 s |
| Aug 7 2012 03:18:57:653PM | 1120807026 | Jim Irby | changes --------------------------------
add some rf results -------------------------------- plasma into rampdown --- h-mode for every ramp |
| Aug 7 2012 03:42:47:420PM | 1120807027 | Jim Irby | changes --------------------------------
change rf a little removed RCUR ramp --- RCUR now flat at 0.659 m prefill from 20 to 18 ms Ote results -------------------------------- plasma into rampdown |
| Aug 7 2012 03:50:44:533PM | 1120807028 | Jim Irby | changes --------------------------------
Ip ramp change: 0.5 s 800 kA 0.7 to 0.8 s, 800 to 1100 kA 1.0 to 1.1 s, 1100 to 800 kA 1.3 to 1.5 s, 800 to 1100 kA, then ramp down Otd results -------------------------------- plasma into rampdown |
| Aug 7 2012 04:08:48:293PM | 1120807029 | Jim Irby | changes --------------------------------
increase rf by 200 kW results -------------------------------- plasma into rampdown |
| Aug 7 2012 04:33:04:873PM | 1120807030 | Jim Irby | changes --------------------------------
more rf results -------------------------------- disruption at 1.07 s |
| Aug 7 2012 04:41:28:237PM | 1120807031 | Jim Irby | changes --------------------------------
IP ramp change: 800 by 0.5 s 0.7 to 0.8 s, 800 to 1100 kA 1.2 to 1.3 s, 1100 to 800 kA 1.4 to 1.5 s, 800 to 1100 kA Otd results -------------------------------- plasma into rampdown |
| Aug 7 2012 04:57:40:010PM | 1120807032 | Jim Irby | changes --------------------------------
rf changes only results -------------------------------- disruption at 1.3 s |
| Aug 7 2012 05:09:34:293PM | 1120807033 | Jim Irby | changes --------------------------------
produce a locked mode load from 1120720008 (locked mode in seg 3) import seg 1 from 1120807032 into seg 1 prepuff from 19 to 17 ms Otd results -------------------------------- plasma for --- nice locked mode |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 08:14:48:910AM | Test | Ok | |
| 2 | 09:03:31:390AM | Plasma | Ok | |
| 3 | 09:19:54:730AM | Plasma | Ok | |
| 4 | 09:34:26:233AM | Plasma | Ok | |
| 5 | 09:48:09:063AM | Plasma | Ok | |
| 6 | 10:06:06:850AM | Plasma | Ok | |
| 7 | 10:20:04:590AM | Plasma | Ok | |
| 8 | 10:35:11:313AM | Plasma | Ok | |
| 9 | 10:48:41:580AM | Plasma | Ok | |
| 10 | 11:04:12:850AM | Plasma | Ok | |
| 11 | 11:18:15:663AM | Plasma | Ok | |
| 12 | 11:31:14:213AM | Plasma | Ok | |
| 13 | 11:45:49:727AM | Plasma | Ok | |
| 14 | 12:00:03:687PM | Plasma | Ok | |
| 15 | 12:17:58:313PM | Plasma | Ok | |
| 16 | 12:31:07:623PM | Plasma | Ok | |
| 17 | 12:48:36:640PM | Plasma | Ok | |
| 18 | 01:03:59:827PM | Plasma | Ok | |
| 19 | 01:23:33:140PM | Plasma | Ok | |
| 20 | 01:38:21:963PM | Plasma | Bad | EF1 commutation failure |
| 21 | 01:53:02:163PM | Plasma | Ok | |
| 22 | 02:06:05:627PM | Plasma | Ok | |
| 23 | 02:20:54:740PM | Plasma | Ok | |
| 24 | 02:35:20:940PM | Plasma | Ok | |
| 25 | 02:57:06:977PM | Plasma | Ok | |
| 26 | 03:11:19:027PM | Plasma | Ok | |
| 27 | 03:26:32:133PM | Plasma | Ok | |
| 28 | 03:45:22:183PM | Plasma | Ok | |
| 29 | 04:00:39:833PM | Plasma | Ok | |
| 30 | 04:16:34:133PM | Plasma | Ok | |
| 31 | 04:36:14:563PM | Plasma | Ok | |
| 32 | 04:50:18:240PM | Plasma | Ok | |
| 33 | 05:04:04:330PM | Plasma | Ok | |
| System Availability | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Aug 7 2012 08:14:31:857AM | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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