| Miniproposals | ||||||||||
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| Operators | |
| Session leader(s): | Yuichi Takase |
| Physics operator(s): | Steve Golovato |
| Engineering operator(s): | Joe Daigle |
| Engineering Operator Run Comment |
| Plasma run |
| Session Leader Plans |
| Physics Operators Plans |
| Session Leader Summaries |
| Entered: Jul 7 2004 03:49:09:053PM |
| Author: To Be Determined |
| 931006 RF Coupling/Heating SL: Takase PO: Golovato EO: Daigle Objective: 1. Raise injected rf power 2. Explore heating once appropriate power level (comparable to OH) is reached Loaded 931005028 with TF flattop extended to 1sec. R_lim=93, R_ant=95 Shot Comments 001 Good shot, but plasma dies outward (nice position scan on loading) 002 Disrupted @ 0.45sec 003 Fizzle 004 Fizzle 005 Early disruption 006 Dud 007 Dud 008 Early disruption 009 Fizzle 010 Fizzle 011 Dud 012 Dud 013 Dud (no rf) 014 Early disruption (no rf) 015 Good shot (no rf) 016 Early disruption (rf on) 017 Fizzle 018 Early disruption 019 Disrupt @ 0.23sec 020 Good shot! Peak rf power = 150kW 021 Good shot again. Peak rf power = 180kW 022 Fizzle 023 Good shot, peak rf power = 300kW 024 Good shot, peak rf power = 360kW 025 Disrupted @ 0.86sec, peak rf power = 440kW 026 Fizzle The first shot of the day was OK, but we lost most of today trying to figure out the changes that appeared in the controllers. (see the physics operator's summary for details.) We got the plasma back on shot 020, and had a total of 6 good shots (001, 020, 021, 023, 024, 025). We made good progress on objective #1, but none on objective #2. Without any attempt for optimization, we were able to exceed the previous power record (250kW) set in August by a substantial amount. Disruptive behavior that was observed at a 100kW power level during the last couple of weeks (with the limiter and antenna farther in) was not observed today. At higher power levels there were definite signs of increased impurity (C, Mo) and deuterium influx, but the radiated power increase was of the order of 1/4 of the injected rf power increase, even at the highest power level (over 400kW on shot 025). This is a very encouraging result, and we plan to optimize limiter/antenna positions and start looking for heating effects. |
| Physics Operator Summaries |
| Entered: Jul 7 2004 04:36:50:427PM |
| Author: To Be Determined |
Physics Operator Run Log - 931006 - Golovato -------------------------------------------- Pre-run Comments ---------------- Starting with shot 931005028 from yesterday, an elongated, diverted shot which had good inner and outer gaps. Want to maintain outer gap to try to recover good icrf power and impurity results from 930819 run. Limiter at 93cm, antenna at 95cm, these are 1cm further out than in august. Starting in pure D, will add H minority later. Keeping TF flat top to 1 sec rather than ramping down as yesterday. Have D in a-side on v14 (PG3), H in b-side-upper on v16 (PG2), and Ar in b-side-lower on v15 (PG1). Plasmas in august were limited, may want to try this if we still have problems gettign power up. Also may want somewhat less elongated if icrf triggers disruptions. 2 hours of ECDC in D from 6-8am preceeded run. B and I still reversed as yesterday. Vessel at 35C. Shot Log -------- ECE valve enabled. 1. Fill at 1.2e-5 of D. Loaded shot 931005028, last good plasma shot from yesterday. Good plasma but ef3s cut out early, at 730ms. ohs response to maintain r_cur also brings down ip, leading to a smooth though early conclusion of the shot. Edge tree not included in this abd next shot. TV now views moly light, showed limiter light up as plasma moved out at end of shot. McPherson, moly monitor, cx valves enabled. 2. Not clear why ef3s worked wrongly, but it didn't appear to be the hybrid. Ran same shot again. Disrupted at 500ms when chopper tripped out. Get growing oscillation in z starting at 300ms leading to disruption. 3. Raised proportional gain in slow (non-chopper) z control. Chopper was at rail in last shot trying to maintain z position. Fizzled as usual after a disruption. 4. Changed offset on Br_0 from -3e-3 to -2.5e-3, Br a little too negative at breakdown. Shot 3 had late breakdown. Try again. Fizzled again. 5. Lowered fill to 1.1e-5, risking a dud. Br is about -2e-3 today, was around 0. yesterday for same settings. Not clear why it is different nor if it is cause of fizzles. The fizzles have had very late breakdowns (at 15ms). Shot 931005028 broke down at 6-7ms. Got good breakdown and current ramp to 200ka, when it went into the inner wall at 65ms. Had runaways. 6. Raised fill back to 1.2e-5. Dud. The hybrid needs fixing. Steves Horne and Wolfe will do it. Something which is left over from monday disk crash. We can't tweak correctly to get things like breakdwon right until this is done. 7. Changed Br_0 offset from -2.5e-2 to -2e-3. Changed r_cur offset from 10000 to 12850, which caused factor to be applied consistently. Dud. 8. Raised fill to 1.3e-5, raised Br_0 offset to -1e-3. Looks like shot 5, disrupted at 200ka, 75ms. Looks like it moves up first then in. 9. Moved pulsed gas earlier by 3ms. Fizzled. Try tweaking null. 10. Raised ef4 30a (2mT) to raise Bz by 2mT, raised Br_0 offset to 0. Fizzled. Bz, Br_0 overdone, move back halfway. 11. Lower fill to 1.2e-5, move pulsed gas later by 3ms. Lowered Bz 15a (1mT), lowered Br_0 to -5.e-4. Dud, probably overdid lowering the gas. 12. Reloaded shot 1, which is the only configuration that ran so far, shot 2 was a repeat of shot 1. Dud. 13. Raised the fill to 1.3e-5, turned off rf. rf discharges on duds and fizzles may have an effect (i.e., gettering). Dud. 14. Changed offset on Br_0 from -3e-3 to -2e-3, raised fill to 1.4e-5. Tuning fields to improve null, raising gas to get at least a fizzle. Got a short 200ka shot, like 5 and 8. Plasma moves up then in. 15. Reapplied factor for r_cur so it is consistent (quoth Wolfe). Good shot, finally. But why???? Ran out to 1.2s. PHA argon puff enabled. 16. Another 200ka early disruption. Lost up before chopper even comes on. 17. Increase oh2u voltage, more positive current, which pushes plasma down (plasma current negative). Moved point at 50ms to 0 from -10. A real fizzle. Perhaps too much fill. 18. Lower fill to 1.3e-5. Another 200ka early loss up. This problem is still not fixed. z_cur feedback is railed, therefore have no vertical control. 19. Problem is offset in z_cur of order 5000. Not sure what sign correction should be, trying +5000 first in slow z_cur. Better, runs to 500ka, 230ms. 20. Correcting both z_cur's by +7000. Also removing change in oh2u, going from 0 to -10 at 50ms. Good plasma again. 21. No changes except more rf power. Good again. 22. Adding H puff, 100v from 422-452ms. Fizzle. 23. Lower fill to 1.2e-5. Good shot. 24. Yes. Another good shot. 25. Three in a row. One more shot to go. Disrupted at 850ms. 26. Ramping the current slightly through shot to fight slight droop. Fizzled, should have lowered fill. Shot Scorecard -------------- Duds 5 Fizzles 7 Plasmas 14 (7 good plasmas, 5 lack of z_cur control, 2 in-between) Post-run Comments ----------------- The lack of consistent operation turned out to be an offset in the z_cur and r_cur feedback which was not noticed until shot 19. This may have always been there, but with the fields reversed the effect was reversed. That is, the offset now tells the controller to move the plasma up even when it is already high (positive feedback). The plasma had to get pretty high and/or the cuurent had to rise sufficiently fast for the error to overcome this offset and pull the plasma back down. This led to 5 shots that died at 200ka, at around 70ms. Sometimes it managed to hold the plasma, as in shots 1, and 15 (shot 15 did have a slightly faster current rise). Shots 2 and 19 may have been in-between cases, being lost about 500ms. Once we corrected this, much more consistent operation resulted. The problems with fizzles and duds early on were from wild goose chases trying to fix things. When things aren't going well, there's no shortage of ideas (usually conflicting) of what to do. The gas fill is running higher than last week, 1.2-1.4e-5 worked this run, although 1.4e-5 was eventually too high and perhaps 1.1e-5 on the last shot might have recovered us from the preceeding disruption. We need to share information and arrive at a strategy to recover from disruptions. |
| Session Leader Comments | |||
| Oct 6 1993 09:53:01:110AM | Yuichi Takase | Today's run is RF conditioning/heating.
The first objective is to raise injected rf power. Once the power is up (appropriate power level to be determined later) we will transition into exploration of heating. | |
| Oct 6 1993 09:54:30:790AM | 931006001 | Yuichi Takase | Shot 001
Good shot, but plasma dies outward starting around 0.73sec. Nice position scan on antenna loading. RF firing from 0.2 to 1.0sec. |
| Oct 6 1993 09:55:00:950AM | 931006002 | Yuichi Takase | Shot 002
Disrupted around 0.45sec. |
| Oct 6 1993 10:12:18:680AM | 931006003 | Yuichi Takase | Shot 003
Fizzle. |
| Oct 6 1993 10:24:28:220AM | 931006004 | Yuichi Takase | Shot 004
Fizzle. |
| Oct 6 1993 10:49:32:840AM | 931006005 | Yuichi Takase | Shot 005
Early disruption. |
| Oct 6 1993 11:18:08:000AM | 931006006 | Yuichi Takase | Shot 006
Dud. (Trying to figure out yesterday's software change.) |
| Oct 6 1993 11:44:00:190AM | 931006007 | Yuichi Takase | Shot 007
Dud. |
| Oct 6 1993 12:07:15:300PM | 931006008 | Yuichi Takase | Shot 008
early disruption |
| Oct 6 1993 12:07:33:800PM | 931006009 | Yuichi Takase | Shot 009
fizzle |
| Oct 6 1993 12:27:27:900PM | 931006010 | Yuichi Takase | Shot 010
fizzle |
| Oct 6 1993 01:18:53:050PM | 931006011 | Yuichi Takase | Shot 011
dud |
| Oct 6 1993 01:19:05:370PM | 931006012 | Yuichi Takase | Shot 012
dud |
| Oct 6 1993 01:19:30:880PM | 931006013 | Yuichi Takase | Shot 013
dud, no rf on this shot |
| Oct 6 1993 01:32:30:620PM | 931006014 | Yuichi Takase | Shot 014
early disruption, no rf on this shot |
| Oct 6 1993 02:03:15:540PM | 931006015 | Yuichi Takase | Shot 015
good shot, no rf on this shot |
| Oct 6 1993 02:15:27:360PM | 931006016 | Yuichi Takase | Shot 016
early disruption |
| Oct 6 1993 02:26:55:730PM | 931006017 | Yuichi Takase | Shot 017
fizzle |
| Oct 6 1993 03:08:21:700PM | 931006018 | Yuichi Takase | Shot 018
early disruption |
| Oct 6 1993 03:41:55:480PM | 931006019 | Yuichi Takase | Shot 019
disrupted @ 0.23sec |
| Oct 6 1993 03:42:47:780PM | 931006020 | Yuichi Takase | Shot 020
Good shot! Peak rf power = 150kW, no impurities. |
| Oct 6 1993 04:10:02:290PM | 931006021 | Yuichi Takase | Shot 021
Good shot again. Peak rf power = 180kW. |
| Oct 6 1993 04:10:24:850PM | 931006022 | Yuichi Takase | Shot 022
Fizzle. |
| Oct 6 1993 05:08:39:290PM | 931006023 | Yuichi Takase | Shot 023
Good shot, peak rf power = 300kW. |
| Oct 6 1993 05:08:58:270PM | 931006024 | Yuichi Takase | Shot 024
Good shot, peak rf power = 360kW. |
| Oct 6 1993 05:09:15:920PM | 931006025 | Yuichi Takase | Shot 025
Good shot, peak rf power = 440kW. |
| Oct 6 1993 05:10:33:970PM | 931006025 | Yuichi Takase | Shot 025
Disrupted @ 0.86sec. |
| Oct 6 1993 05:10:05:290PM | 931006026 | Yuichi Takase | Shot 026
Fizzle |
| Physics Operator Comments |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 09:15:11:050AM | Plasma | Bad | Ef# inverted early. |
| 2 | 09:43:24:800AM | Plasma | Ok | EF3 inverted early. |
| 3 | 10:02:48:000AM | Plasma | Ok | Ef3 inverted early. |
| 4 | 10:20:16:410AM | Plasma | Ok | No faults. |
| 5 | 10:41:16:610AM | Plasma | Ok | Plasma shot O.K. |
| 6 | 11:00:09:380AM | Plasma | Ok | Good shot |
| 7 | 11:15:36:260AM | Plasma | Ok | Plasma shot no faults. |
| 8 | 11:34:56:570AM | Plasma | Ok | Plasma sshot OK |
| 9 | 12:00:41:720PM | Plasma | Ok | no faults |
| 10 | 12:24:02:060PM | Plasma | Ok | no faults |
| 11 | 12:42:26:180PM | Plasma | Ok | Plasma shot OK. |
| 12 | 12:56:43:170PM | Plasma | Ok | Plasma shot |
| 13 | 01:12:09:880PM | Plasma | Ok | Complele dud No faults. |
| 14 | 01:28:15:340PM | Plasma | Ok | Plasma shot Fizzle No faults. |
| 15 | 01:48:23:480PM | Plasma | Ok | PLasma shot No faults ok. |
| 16 | 02:04:57:790PM | Plasma | Ok | Plasma shot no faults. |
| 17 | 02:20:50:230PM | Plasma | Ok | Plasma shot no faults. |
| 18 | 02:38:10:290PM | Plasma | Ok | Plasma shot no faults |
| 19 | 03:09:31:000PM | Plasma | Ok | no faults |
| 20 | 03:23:22:890PM | Plasma | Bad | OH1 &EF1U & L faulted at disruption |
| 21 | 03:38:44:020PM | Plasma | Ok | Good shot |
| 22 | 03:54:44:510PM | Plasma | Ok | plasma fizzle no faults. |
| 23 | 04:11:16:150PM | Plasma | Ok | no faults |
| 24 | 04:28:39:670PM | Plasma | Ok | Plasma shot no faults. |
| 25 | 04:45:08:250PM | Plasma | Ok | Good shot no faults. |
| 26 | 05:00:23:780PM | Test | Bad | |