| Miniproposals | ||||||||||
|
| Operators | |
| Session leader(s): | Miklos Porkolab |
| Physics operator(s): | Ron Parker |
| Engineering operator(s): | Unknown |
| Engineering Operator Run Comment |
| Continuation of MP 324A, Current Ramp Studies. Porkolab/Parker |
| Session Leader Plans |
| Physics Operators Plans |
| Session Leader Summaries |
| Entered: Jul 7 2004 03:49:31:383PM |
| Author: To Be Determined |
| Session Leader Summary for 1021023. This run was a continuation of MP 324A, ITB Formation with two-frequency ICRF in Optimized Shear Plasma. We continued from the previous day and did a current scan by varying the ramping up to 700kA, 800 kA, and 900 kA. It was determined that ramping up to 900 kA produced the best stored energy and electron temperatures, with Te up to 5.0 keV before sawtooth activity set in. Since we pushed the power up to 4.0 MW at 900 kA, Zeff was relatively high, perhaps up to 3.0. Radiated power, however, was 2.0 MW, about 40% of the total injected power before sawteeth set in. Consequently, the sawteeth came in at about 0.25-0.26 second after the start of the current rampup even though the temperature was high. Coupling of the RF power was reliable and excellent, with D and E ports each injecting 1.4 MW starting at 0.07 sec into the ramp, and J port up to 1.2 MW starting after 0.1sec (J had problems trying to couple at 0.07 sec). After an excellent target plasma was established on shot 019 (with 4.0 MW of Rf power and a neutron rate of 5.0x10^12, just before the first sawtooth), we continued with Li pellet injection and MSE scans to measure the q-profile and/or changes in the magnetic field pitch at different times during current rampup. After several fizzles, the RF power level was reduced to 3.7 MW (shots 25-27) to obtain reproducible shots for the pellet/ MSE scans. Shot 28 was an ohmic only shot for baseline purposes. In sum an excellent runday, with good progress in the diagnostic area. However, did not get to plasma rotation measurements with Ar injection. Another day could be spent on further data collection with the current profile diagnostics, with MSE and Li pellet, as well as toroidal rotation measurements with Ar injection. Such a run would also help with further data for two Ph.D. thesis work. |
| Physics Operator Summaries |
| Entered: Jul 7 2004 04:37:16:630PM |
| Author: To Be Determined |
| Engineering Setup and Run Plan for Wednesday, October 23, 2002 Continuation of MP 324A, Current Ramp Studies SL: Porkolab PO: Parker Overnight Bake @ 60 C, ECDC Overnight in D2 @ 2e-4 Torr until 07:00 Run Begins at 09:00 and ends at 17:00 Power systems setup the same as for Shot 1021022025 Gas setup: B-Top 6 psi D2 Hybrid Enabled (PG4) B-side lower 1 psi Ar Hybrid Enabled (PG1) B-side upper 10 psi D2 Hybrid DISABLED (PG2, for ECDC) C-Side 30 psi D2 Hybrid Enabled (PG3) J-Bottom leave as is, Hybrid DISABLED Enable the following gate valves, assuming no vacuum problems: ECE, VUV, DNB RF Setup: Transmitters 1,2&3 in Run On by 07:00 RUN PLAN: We'll continue exploring the startup with early application of RF in order to slow down current penetration, delay sawteeth and try to form a transport barrier. Run Summary The purpose of the run was to continue MP 324A, the effect of current ramp and early RF heating on delaying the current penetration and keeping the central q above 1. The day started with shots in the 700 kA range, but for these shots the delay in the sawtooth onset with RF power was not significant. Therefore the current was increased to 900 kA and most of the shots were at this current level. RF power was quite reliable at levels up to 4 MW, with D&E contributing ~2.7 MW and J the rest. (J was in a two-stap configuration). Data on the crrent profile was taken with lithium pellet injection and MSE. The machine ran very well, with startup problems due only to disruptions or, in one case, failure of the density feedback system. After a disruption, it seems that the gas fill pulse needs to be reduced by a few ms. The scorecard: 28 shots attempted, 18 succeeded without disruption, 6 with disruption (some caused by pellet) and 4 fizzles, either after a disruption or after a failure of the density feedback system. |
| Session Leader Comments | |||
| Oct 23 2002 09:13:14:473AM | 1021023001 | Miklos Porkolab | Starting at 5.4 T, ramp to 0.8 MA. Shot number one produced good plasma. Also, put in full power. J port starting first with 0.8 MW at 0.07 sec, followed by D+E at 2.0 MW. Sawteeth delayed to 0.3 sec, Te=4 keV; |
| Oct 25 2002 11:34:30:927AM | 1021023001 | Miklos Porkolab | ITB Formatiion with Two Frequency ICRF in Optimized Shear Plasmas with Ip Ramp Miniproposal 324A-Continued Objective is to collect rotation data with MSE, HIREX, and Pellet Tune-up shot |
| Oct 23 2002 09:39:44:493AM | 1021023002 | Miklos Porkolab | Continue at 5.4 T, ramp to 0.8 MA. Good shot. Also, put in 3.2 MW. J port starting first with 0.8 MW at 0.07 sec, followed by D+E at 2.4 MW. Sawteeth delayed to 0.25sec, Te=4.5keV; Neutron rate 3.5x10^12 before sawteeth, 6x10^12 after sawteeth. J port still trips out at the beginning, but stays up later . |
| Oct 23 2002 09:58:30:427AM | 1021023003 | Miklos Porkolab | Continue at 5.4 T, ramp to (0.7-)0.8 MA. Good shot. Also, put in 3.2 MW. J port starting first with 0.8 MW at 0.07 sec, followed by D+E at 2.4 MW. Sawteeth delayed to 0.25sec, Te=4.5keV; Neutron rate 3.0x10^12 before sawteeth, 6x10^12 after sawteeth. J port still trips out at the beginning, but stays up later . |
| Oct 23 2002 10:20:58:150AM | 1021023004 | Miklos Porkolab | Continue at 5.4 T, ramp to 0.7 MA. Good shot. Also, put in 3.2 MW. J port starting first with 0.8 MW at 0.07 sec, followed by D+E at 2.4 MW. Sawteeth delayed to 0.25sec, Te=4.0keV; Neutron rate 3.0x10^12 before sawteeth, 6x10^12 after sawteeth. J port power reduced to 500 kW at the beginning, then ram up to 0.8 MW |
| Oct 23 2002 10:31:36:057AM | 1021023005 | Miklos Porkolab | Continue at 5.4 T, ramp to 0.7 MA. Good shot. Also, put in 3.2 MW. J port starting first with 0.8 MW at 0.07 sec, followed by D+E at 2.4 MW. Sawteeth delayed to 0.25sec, Te=4.0keV; Neutron rate 3.0x10^12 before sawteeth, 6x10^12 after sawteeth. J port power reduced to 500 kW at the beginning, then ram up to 0.8 MW . J port still trips at the beginning (0.07 sec). D+E applied at 0.1sec. |
| Oct 23 2002 10:50:50:400AM | 1021023006 | Miklos Porkolab | Continue at 5.4 T, but now ramp to 0.9 MA slowly, but sawtooth free period is at 750 kA.. Also, put in 3.2 MW. Shot disrupted later time. J port starting first with 0.8 MW at 0.07 sec, followed by D+E at 2.4 MW. Sawteeth delayed to 0.25sec, Te=4.0keV; Neutron rate 3.0x10^12 before sawteeth, 6x10^12 after sawteeth. J port power reduced to 500 kW at the beginning, then ram up to 0.8 MW . J port still trips at the beginning (0.07 sec). D+E applied at 0.1sec. |
| Oct 23 2002 11:03:20:670AM | 1021023007 | Miklos Porkolab | Continue at 5.4 T, but now ramp to 0.9 MA slowly, . Also, put in 3.2 MW. Fizzle. |
| Oct 23 2002 11:24:28:330AM | 1021023008 | Miklos Porkolab | Continue at 5.4 T, but now ramp to 0.9 MA slowly. Also, put in 3.2 MW. Good shot, but current ramp still slow. T(e) =5.0 keV before sawteeth start at 0.23 sec. |
| Oct 23 2002 11:33:12:420AM | 1021023009 | Miklos Porkolab | Continue at 5.4 T, but now ramp to 0.9 MA slowly. But got only to 0.8 MA at 0.25 sec. Also, put in 3.2 MW. D+E injected early at 0.07 sec, then inject J port at 0.1 sec. This seems to work for the RF. T(e) =5.0 keV before sawteeth start at 0.245 sec. |
| Oct 23 2002 11:52:00:023AM | 1021023010 | Miklos Porkolab | Continue at 5.4 T, but now ramp to 0.9 MA faster. Got to 0.9MA at 0.25 sec. Also, put in 3.6 MW. D+E injected early at 0.07 sec, then inject J port at 0.1 sec. T(e) =5.0 keV before sawteeth start at 0.26 sec. Injected Li pellet at 1.4 sec, which disrupted shot. |
| Oct 23 2002 12:07:53:697PM | 1021023011 | Miklos Porkolab | Continue at 5.4 T, maintain ramp to 0.9 MA at . Got to 0.85MA at 0.25 sec. Also, put in 3..9 MW. D+E injected early at 0.07 sec, then inject J port at 0.1 sec. T(e) =5.0 keV before sawteeth start at 0.26 sec. Ramp J port from 0.8 MW at 0.1 sec , to 1.2 MW at 0.15 sec. Maiintain D+E at 2.5 MW at 0.07 sec. Disrupted at 0.27sec; gas fill a little low, density is only at 5x10^19. |
| Oct 23 2002 01:23:48:320PM | 1021023012 | Miklos Porkolab | Continue at 5.4 T, maintain ramp to 0.9 MA at . Fizzle. |
| Oct 23 2002 01:35:09:590PM | 1021023013 | Miklos Porkolab | Continue at 5.4 T, maintain ramp to 0.9 MA at . Disruption at 0.27 sec. Total power injected is 4.0 MW. Te=5.0 keV before disruption at the first sawtooth. (?) |
| Oct 23 2002 01:37:01:190PM | 1021023014 | Miklos Porkolab | Continue at 5.4 T, maintain ramp to 0.9 MA at . Disruption at 0.27 sec. Total power injected is 3.5 MW. Te=5.0 keV before disruption at the first sawtooth. (?) |
| Oct 23 2002 01:42:26:567PM | 1021023015 | Miklos Porkolab | Continue at 5.4 T, maintain ramp to 0.9 MA . No disruption. Power from J port shut off, power from D+E=2.8 MW. Te=5.0 keV before disruption at the first sawtooth(?). |
| Oct 23 2002 01:52:37:910PM | 1021023016 | Miklos Porkolab | Continue at 5.4 T, maintain ramp to 0.9 MA . No disruption. Power from J port shut off, power from D+E=2.8 MW. Te=5.0 keV before disruption at the first sawtooth. Also, after 0.5 sec, looks like sawteeth change charater, look like "monster sawteeth", at least Te increases and the sawtooth period increases substantially. |
| Oct 23 2002 04:12:58:770PM | 1021023017 | Miklos Porkolab | Continue at 5.4 T, maintain ramp to 0.9 MA . No disruption. Power from J = 0.6 MW, power from D+E=2.8 MW. Te=5.0 keV before disruption at the first sawtooth at 0.25sec. Neutron rate is 4x10^12 just before first sawtooth, and stored energy is 55 kJ. |
| Oct 23 2002 04:00:00:940PM | 1021023018 | Miklos Porkolab | Good shot, sawtooth delayed to 0.255 sec, stored energy 60 kJ before first sawtooth. 5.4 T, current ramped to 0.9 MA. No disruption. Power from J = 1.0 MW, power from D+E=2.8 MW. Te=5.0 keV before disruption at the first sawtooth at 0.25sec. Neutron rate is 5x10^12 just before first sawtooth, and stored energy is 60 kJ. |
| Oct 23 2002 03:57:52:577PM | 1021023019 | Miklos Porkolab | Good shot, sawtooth delaye to 0.265 sec, stored energy 60 kJ before first sawtooth. Continue at 5.4 T, maintain ramp to 0.9 MA . No disruption. Power from J = 1.2 MW, power from D+E=2.8 MW total power 4.0 MW. Te=5.0 keV before firsat sawtooth. Neutron rate is 5x10^12 just before first sawtooth, and stored energy is 60 kJ. Radiated power at 2.0 MW . |
| Oct 23 2002 02:55:21:963PM | 1021023020 | Miklos Porkolab | Fired pellet at 0.23 second. Survived shot. RF power tripped out before pellet, then recovered. Continue at 5.4 T, maintain ramp to 0.9 MA . No disruption. Power from J = 1.2 MW, power from D+E=2.8 MW total power 4.0 MW. |
| Oct 23 2002 03:11:01:370PM | 1021023021 | Miklos Porkolab | No pellet, even though tried to inject.. RF power lowered to 3.7 MW, good, clean RF. Continue at 5.4 T, maintain ramp to 0.9 MA . No disruption. Power from J = 1.0 MW, power from D+E=2.7MW total power 3.7 MW. Te=5.0 keV, ne(0)=1.3x10^20. |
| Oct 23 2002 03:12:34:170PM | 1021023022 | Miklos Porkolab | Fizzle. Continue at 5.4 T, maintain ramp to 0.9 MA . |
| Oct 23 2002 03:20:40:837PM | 1021023023 | Miklos Porkolab | Fizzle. Continue at 5.4 T, maintain ramp to 0.9 MA . |
| Oct 23 2002 03:56:56:527PM | 1021023024 | Miklos Porkolab | Good shot with pellet, however Prf=1.5 MW only. Continue at 5.4 T, maintain ramp to 0.9 MA . No data collection from pellet, however. Shot not particularly interesting. |
| Oct 23 2002 04:12:05:270PM | 1021023025 | Miklos Porkolab | Good shot with rather small pellet, Prf=3.7 MW. Continue at 5.4 T, maintain ramp to 0.9 MA . Pellet killed RF, plasma cooled down during pellet. Plasma survived but stayed cool. |
| Oct 23 2002 04:28:36:310PM | 1021023026 | Miklos Porkolab | Good shot with rather small pellet, Prf=3.7 MW. Continue at 5.4 T, maintain ramp to 0.9 MA . Pellet injected at 0.29 sec, after first sawtooth (at 0.28 sec, Te=5.0 keV). Good shot, did not disrupt plasma, should be able to make good pellet/q profile measurements. MSE also collecting good data. Next two shots will be ohmic shots to provide base line for MSE diagnostics. |
| Oct 23 2002 04:31:51:627PM | 1021023027 | Miklos Porkolab | Injected pellet at 0.16 sec, Prf dropped out, but recovered at 3.7 MW. Te decreases from 3 keV to 2 keV during pellet, then reheats after 30 ms back to 5.0 keV at 0.25 sec. |
| Oct 23 2002 05:01:28:750PM | 1021023028 | Miklos Porkolab | Injected pellet at 0.23 sec, OHMIC base shot, no RF. Te=2.0 keV just before pellet injection. Drops to 0.5 keV during pellet. Then recovers. COmputer problems showed up, missing some dat. Terminated run at 4.58 pm. |
| Oct 23 2002 05:11:55:660PM | 1021023028 | Miklos Porkolab | Injected pellet at 0.23 sec, OHMIC base shot, no RF. Te=2.0 keV just before pellet injection. Drops to 0.5 keV during pellet. Then recovers. Computer problems showed up, missing some data. Terminated run at 4.58 pm. |
| Physics Operator Comments | |||
| Oct 23 2002 09:19:58:463AM | 1021023001 | Ron Parker | This run will continue to explore current ramp scenarios as described in mini-proposal MP 324. M. Porkolab is the session leader, R. Parker the PO. We started with a shot that replicated the last shot on 10/22/02. Shot 1 ran well with 2.8 MW RF, I = 800 kA and neL04 ~ 0.6e14 cm-3. |
| Oct 23 2002 09:31:16:247AM | 1021023002 | Ron Parker | Shot 2 ran well, same as shot 1 but RF power ~ 3.2 MW. Next shot: I = 700 kA. |
| Oct 23 2002 09:49:14:867AM | 1021023003 | Ron Parker | Shot 3 ran again well, but the current overshot the 700 kA target. As this shot had runaways that perturbed the current rise, 2 ms of additional fill gas will be added for the next shot. |
| Oct 23 2002 10:07:01:090AM | 1021023004 | Ron Parker | Shot 4 ran well, the extra gas seemed to help the runaway problem. For the next shot, we'll lower the voltage on OH1 in Segment 2 from 250 to 200 Volts, in order to reduce the overshoot. |
| Oct 23 2002 10:18:56:550AM | 1021023005 | Ron Parker | Shot 5 ran well, current ~ 700 kA. Steve Wolfe taking over as PO for the next few shots |
| Oct 23 2002 10:43:16:313AM | 1021023006 | Steve Wolfe | shot#6: wolfe taking over as physop from parker. Go t 900kA, not reaching fltattop until 400msec initial seg2 oh1 volt left at 200 add 1msec to pg4 plasma disrupted at 1.56, but bounced at startup, got runaways. sawteeth start at .25sec ip drops at about the same time, loop voltage jumps in response. next shot: raise pg4 by 2msec to 34msec |
| Oct 23 2002 10:51:41:057AM | 1021023007 | Steve Wolfe | shot#7: raise pg4 by 2msec to 34msec to get rid of runaways fizzle. shouldn't have raised it after a disruption. It went in. next shot: try again, it may have cleaned up. |
| Oct 23 2002 11:11:22:320AM | 1021023008 | Steve Wolfe | shot#8: pg4 at 34msec to get rid of runaways slow down ef4 rampdown after 1.5sec - only thing I can see that might have caused disruption on 6. plasma, still disrupting in rampdown, at 1.75 this time. NO runaways,but sawteeth start at .23 next shot: 900 at .3sec (or bust) |
| Oct 23 2002 11:26:03:270AM | 1021023009 | Steve Wolfe | shot#9: 900kA at .3sec ; Earl will shoot Li pellet at 1.4sec plasma, ramped down, pellet at 1.4 first sawtooth at .245 next shot: speed up current rise some more |
| Oct 23 2002 11:45:26:207AM | 1021023010 | Ron Parker | Parker back as PO. Shot 10 ran well until a pellet-induced disruption. We'll reduce the gas by 4 ms to try to salvage the next shot, which is lokely to fizzle. |
| Oct 23 2002 12:09:58:047PM | 1021023011 | Ron Parker | Shot 11 disrupted at 0.29 s. J-port power had been increased to ~1.3 MW, bring the total power up to 3.8 MW. It could be that the lower density from the reduced gas pre-programming was a factor in the disruption. We'll restore the gas for the next shot. |
| Oct 23 2002 12:20:16:813PM | 1021023012 | Ron Parker | Shot 12 fizzled, we'll try it again. |
| Oct 23 2002 12:47:28:130PM | 1021023013 | Ron Parker | Shot 13 once again disrupted early, around 270 ms. RF may be contributing, so we'll back off on J-port power to try to recover the shot. |
| Oct 23 2002 01:07:25:677PM | 1021023014 | Ron Parker | Shot 14 disrupted at the same time, although J-port power had been reduced. We'll raise the density 10% on the next shot. |
| Oct 23 2002 01:19:06:777PM | 1021023015 | Ron Parker | Shot 15 ran well with D&E only producing 2.7 MW. For next shot, we'll try to bring J-port back. |
| Oct 23 2002 01:32:42:287PM | 1021023016 | Ron Parker | Shot 16 ran well, but J-port had not been activated. Try again with J-port at ~ 600 kW. |
| Oct 23 2002 01:46:06:983PM | 1021023017 | Ron Parker | Shot 17 ran well. J-port produced 600 kW for a total of 3.3 MW, lasting until 0.6 s with a clean pulse. Next shot: raise J-port to 1.0 MW. |
| Oct 23 2002 02:11:52:873PM | 1021023018 | Ron Parker | Shot 18 ran well with 3.7 MW of RF. Next shot: Increase power from J-port |
| Oct 23 2002 02:24:43:760PM | 1021023019 | Ron Parker | Shot 19 ran well with 4 MW of RF power. For next shot, we'll fire Li pellet in early phase to get a measure of q(r). |
| Oct 23 2002 02:39:33:490PM | 1021023020 | Ron Parker | Shot 20 went well, Li pellet fired ~ 0.23 s. RF was a bit ragged. Try again, with power somewhat reduced. |
| Oct 23 2002 02:58:18:940PM | 1021023021 | Ron Parker | Shot 21 ran well without Li pellet injection, but with 3.7 MW RF Next shot: Repeat with pellet. |
| Oct 23 2002 05:10:50:767PM | 1021023022 | Ron Parker | Shot 22 fizzled, probably because at the end of the previous shot, the gas feedback system failed and flooded the machine with gas. Try again the next shot. |
| Oct 23 2002 03:25:32:197PM | 1021023023 | Ron Parker | Shot 23 also fizzled. No change for next shot. |
| Oct 23 2002 03:33:40:220PM | 1021023024 | Ron Parker | Shot 24 went off OK. |
| Oct 23 2002 03:53:09:297PM | 1021023025 | Ron Parker | Shot 25 ran well with a pellet and the camera. In these next shots, we'll vary the time of injection of the pellet. |
| Oct 23 2002 04:06:52:260PM | 1021023026 | Ron Parker | Shot 26 ran well, next shot: the dreaded Argon will be injected. |
| Oct 23 2002 04:22:48:440PM | 1021023027 | Ron Parker | Shot 27 ran well, but disrupted shortly after rampdown. Next two shots will be Ohmic. Since there was a disruption, the gas will be reduced 2ms for the next shot.. |
| Oct 23 2002 04:48:59:780PM | 1021023028 | Ron Parker | Shot 28 was an Ohmic shot and ran well. |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 09:03:05:600AM | Plasma | Ok | |
| 2 | 09:22:22:737AM | Plasma | Ok | |
| 3 | 09:38:31:690AM | Plasma | Ok | |
| 4 | 09:55:35:387AM | Plasma | Ok | |
| 5 | 10:13:04:203AM | Plasma | Ok | |
| 6 | 10:33:07:843AM | Plasma | Ok | |
| 7 | 10:48:08:953AM | Plasma | Ok | |
| 8 | 11:04:51:817AM | Plasma | Ok | |
| 9 | 11:20:02:363AM | Plasma | Ok | |
| 10 | 11:36:44:523AM | Plasma | Ok | |
| 11 | 11:57:15:587AM | Plasma | Ok | |
| 12 | 12:14:42:000PM | Plasma | Ok | |
| 13 | 12:35:24:720PM | Plasma | Ok | |
| 14 | 12:50:38:733PM | Plasma | Ok | |
| 15 | 01:06:51:223PM | Plasma | Ok | |
| 16 | 01:21:35:643PM | Plasma | Ok | |
| 17 | 01:37:05:270PM | Plasma | Ok | |
| 18 | 01:53:17:193PM | Plasma | Ok | |
| 19 | 02:11:57:203PM | Plasma | Ok | |
| 20 | 02:27:31:517PM | Plasma | Ok | |
| 21 | 02:44:40:540PM | Plasma | Ok | |
| 22 | 03:02:19:953PM | Plasma | Ok | |
| 23 | 03:16:40:607PM | Plasma | Ok | |
| 24 | 03:30:29:290PM | Plasma | Ok | |
| 25 | 03:45:48:960PM | Plasma | Ok | |
| 26 | 04:01:48:993PM | Plasma | Ok | |
| 27 | 04:16:20:450PM | Plasma | Ok | |
| 28 | 04:31:46:877PM | Plasma | Ok | |