| Miniproposals | ||||||||||
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| Operators | |
| Session leader(s): | T.C. Hender,Steve Wukitch |
| Physics operator(s): | Joseph Snipes |
| Engineering operator(s): | Bill Cochran,Gary Dekow,Bill Byford |
| Engineering Operator Run Comment |
| MP#398 Complete identity experiments with JET on error field locked mode |
| Session Leader Plans |
| Entered: Mar 9 2005 04:07:07:423AM |
| Author: T.C. Hender |
| Run Plan for Thursday, 10-March-2005 AM
MP#398 Complete identity experiments with JET on error field locked mode thresholds SL: Hender/Wolfe PO: Snipes Run begins at 10:30 and ends at 14.30 Note: Acoil configuration (-Btop+Dbot+Gtop-Jbot) RF Setup: NONE - no RF for this run. --------------------------------------------------------------- Run Plan for MP#398: q95=3.2 (I=0.81MA, B=4T, "JET shape") With ( -Btop+Dbot+Gtop-Jbot) trying to get LM data at lower field (4T): 1. Establish 4T discharge based on 1040413029 (6.3T) with a target of nl04~1x10^20m-2. No A-coil current on this shot, in order to confirm no intrinsic locked mode forms. Check shape agrees with 1040413029 2. Repeat 1. exploring highest density before detachment which is expected to be around nl04~1.5x10^20m-2 3. Repeat 2. With 2kA square wave in A-coil from 0.8s to 1.28s. And then vary A-coil current up and down to refine LM threshold. Then with(Btop-Dbot-Gtop+Jbot) [just reverse the supply leads] trying to get LM data at 4T again: 4. Repeat 3 with the reversed A-coil phase If time allows (unlikely) try to get some 6.3T data but (unfortunately) need ( -Btop+Dbot+Gtop-Jbot) again. i.e. another supply lead swap 5. Repeat 1040413029 exactly. End at 14.30 or as soon thereafter as possible |
| Entered: Mar 10 2005 11:48:44:370AM |
| Author: Steve Wukitch |
| Plan for 10-Mar-2005 part 2 MP#355: SL: Wukitch PO: Snipes Overnight ECDC in D2, bake at 60C Engineering setup: Power systems as on 1050309021 A-coils off unless left in locked mode-suppression configuration Gas setup: ----------- fill B-Top with 6 psi D2 Hybrid Enabled (PG4) fill B-side lower with 1 psi Ar Hybrid DISabled (PG1) fill B-side upper with psi D2 Hybrid DISabled (PG2) fill (former) C-side with 30 psi D2 Hybrid Enabled (PG3) Torvac Setup: -------------- GV1 closed, Bypass to RGA open Torus gate valves closed in Pulse for 5min after shot Gate valves: ECE (assuming no vac problems) and Z-bolo/shutter open --------------------------------------------------------- Plan: We will continue the simple and dull plasma operation for antenna conditioning. We want to obtain as many discharges as possible to plasma condition antennas and will be the focus of the run. J antenna will be at 78 MHz and [0,pi,0,pi] phasing using D(H) minority. Start with vanilla LSN, 5.4 T, Ip=0.8 MA, nl_04=0.8 target discharge (1050309021 except nl_04->0.8 instead of 1.1-1.5). Upper null discharges can be run if parties are interested (1050209019 is a good starting point but with lower target density). The aim is to get 1 MW from each for 0.5 sec then combine and maximize injected power limited by coax voltage limits (only have N2 in D and J antenna). Monitor density and impurity evolution for trends with RF power. --------------------------------------------------------- |
| Physics Operators Plans |
| Entered: Mar 9 2005 06:24:54:997PM |
| Author: Joseph Snipes |
| Engineering setup for Wednesday, 10 Mar 2005 MP 398: Complete Identity Experiments with JET on Error Field Locked Mode Thresholds Session leader: T. Hender/S. Wolfe Physics operator: J. Snipes Overnight ECDC in D2 stopping two hours before the run Run begins at 10:30 and ends at 18:00. Power systems as on 1050304024 except A-coil configuration (-Btop+Dbot+Gtop-Jbot), current limit set to 3 kA, 600 V, A-coil start time set to 0.3 s, invert 2.0 s, OH1 and OH2 current limits set to [-30,+30] kA. If we get to step 5 in the run plan, we will then need to increase TF current limits to 180 kA. Gas Setup: fill B-Top with 6 psi D2 Hybrid enabled (PG4) fill B-side lower with 40 psi D2 Hybrid disabled (PG1) leave B-side upper with He3 Hybrid disabled fill (former) C-side with 40 psi D2 Hybrid enabled (PG3) leave J-bot Hybrid disabled (PG2) Torvac setup: GV1 closed; bypass to RGA open Torus gate valves closed during pulse and for 5 minutes after each shot Enable the following gate valves, assuming no vacuum problems: ECE Necessary diagnostics: TCI, VB, magnetics Due to a large number of disruptions expected in this run, the VUV gate valve and Z-bolo shutter should be closed, which will also block out HIREX-Jr. ------------------------------------------------------------------------------- RF Setup: Absolutely NO RF TODAY ! ------------------------------------------------------------------------------- Run plan: q95=3.2 (Ip = 0.81 MA, BT = 4T, "JET shape") With ( -Btop+Dbot+Gtop-Jbot) trying to get LM data at lower field (4T): Note this equilibrium seems to be prone to making the TCI feedback fail, so we may want to run either nl_Zmeter or just pre-programmed gas puff if it isn't better than it was last time. 1. Establish 4T discharge based on 1040413029 (6.3T) with a target of nl04~1x10^20m-2. No A-coil current on this shot, in order to confirm no intrinsic locked mode forms. Check shape agrees with 1040413029 2. Repeat 1. exploring highest density before detachment which is expected to be around nl04~1.5x10^20m-2 3. Repeat 2. With 2kA square in A-coil from 0.8s to 1.28s. And then vary A-coil current up and down to refine LM threshold. Then with(Btop-Dbot-Gtop+Jbot) [just reverse the supply leads] trying to get LM data at 4T again: 4. Repeat 3 with the reversed A-coil phase If time allows (unlikely) try to get some 6.3T data but (unfortunately) need ( -Btop+Dbot+Gtop-Jbot) again. i.e. another supply lead swap 5. Repeat 1040413029 exactly. |
| Session Leader Summaries |
| Entered: Mar 10 2005 06:07:15:213PM |
| Author: Steve Wukitch |
| Summary: Antenna operation improved significantly during the course of the day. D antenna was vacuum conditioned before the run and this appears to have removed the arc. This is likely a result of something on the vacuum side since it cleaned up with some conditioning. D antenna reached ~1.4 MW for 0.4 sec and some verification of DC1 needs to be done. E antenna ran well up to 1.5 MW and operated well overlapped with D antenna. J antenna started poorly due to conditioning. We have some concerns the spray seen in the videos is depositing material onto J deteriorating the antenna condition. We also have been visited by a phase lock problem that we will address with some vacuum testing. We also need to spend time investigating where the RF is leaking (J4 appears worse than J3). |
| Entered: Mar 11 2005 03:46:45:160AM |
| Author: T.C. Hender |
| The aim of this session was to continue the C-Mod/JET/DIII-D error field experiment by establishing the B-field scaling. The required JET/DIII-D identity shape at 4T, and q95=3.2, was established in 3 pulses. Shot 3 indicated a density limit around nl04~1.6e20 at 4T.
The A-coil was used from shot 5 onwards with the wiring Btop -Dbot -Gtop +Jbot. A positive phase of A-coil current (was accidentally) used first - shots 5,9 and 10 were successful with A-coil currents up to +3.5kA and density down to nl04=1.e20, but no evident locked modes. If this result is confirmed by further analysis then it places a bound on locked mode thresholds. From shots 11 to 13 negative A-coil current was applied (or equivalently the wiring was -Btop+Dbot+Gtop-Jbot). The only successful pulse was shot 13 which showed the only clear error locked mode of the session at 0.925s. In this 1/2 day session there were 3 fizzles and 1 dud. Also relatively poor breakdown led to early MHD and disruptions in at least 2 shots. Overall useful data was obtained but probably some more pulses with -Btop+Dbot+Gtop-Jbot are needed to establish the locked mode threshold at 4T. |
| Physics Operator Summaries |
| Entered: Mar 10 2005 06:14:01:573PM |
| Author: Joseph Snipes |
| Summary: The first part of the run on error field identity with JET did not go all that well in that few locked modes were found. The ICRF injected a few MW and some brief H-modes were driven. There were also some very short initial LHCD pulses at 0.5 s that were particularly visible during a fizzle in front of the LH grill on the camera view. Overall, the machine ran pretty well. There were difficulties with the startup and a number of shots had hard x rays early on. It seems that the RCUR offset should be set to at least 1500 and perhaps even a bit higher might improve the startup. The last three shots had the offset at 1500 and their current rises were a bit slow but otherwise good. Out of 26 shots, there were 5 fizzles, two computer system tests, one dud, and 18 plasmas. |
| Session Leader Comments | |||
| Mar 10 2005 11:02:24:040AM | 1050310001 | T.C. Hender | Fizzle.
|
| Mar 10 2005 11:10:18:353AM | 1050310002 | T.C. Hender | Got a good plasma at the target density, nl_04=1.1e20. Shot ran through with no locked mode. Outer gap slightly too large by ~1cm. |
| Mar 10 2005 11:24:44:510AM | 1050310003 | T.C. Hender | nl_04 ~ 1.6e20. Disrupted at 1.3sec, density limit? Sawteeth not very visible on ECE, maybe in cut-off? Go to an intermediate density for the next shot. |
| Mar 10 2005 11:36:11:040AM | 1050310004 | T.C. Hender | Density slightly higher than 1050310002, nl_04=1.23e19. Small sawteeth visible, no locked mode evident. Proceed to use this shot as the target shot for the A coil. |
| Mar 10 2005 12:24:35:587PM | 1050310005 | T.C. Hender | Disrupted at 1.35sec. No clear sign of a locked mode (slight possibility of a locked mode around 0.6sec when sawtooth behaviour changes). Sawteeth are quite small, but still present through the shot. Acoil current=2kA +Btop -Dbot -Gtop +Jbot. |
| Mar 10 2005 12:03:50:370PM | 1050310006 | T.C. Hender | Fizzle.
|
| Mar 10 2005 12:51:34:743PM | 1050310007 | T.C. Hender | Early disruprion at 0.62sec, before A coil starts. Possible locked mode at 0.19sec, and 0.52sec. |
| Mar 10 2005 12:59:51:963PM | 1050310008 | T.C. Hender | Fizzle |
| Mar 10 2005 01:25:26:933PM | 1050310009 | T.C. Hender | Disruption at 0.99sec, but no sign of a locked mode. Try lowering the density slightly.
|
| Mar 10 2005 02:34:12:743PM | 1050310010 | T.C. Hender | Possible locked mode at 1.48sec, but in plasma current rampdown phase. nl_04=1.e20. Acoil current = 3.5kA. +Btop -Dbot -Gtop +Jbot. |
| Mar 10 2005 02:18:10:980PM | 1050310011 | T.C. Hender | Fringe jumps in nl_04. Possible natural locked mode at around 0.4sec, the sawteeth peter out at this time. Shot runs through until the rampdown phase. A coil current = 2kA, -Btop +Dbot +Gtop -Jbot. |
| Mar 10 2005 02:24:15:730PM | 1050310012 | T.C. Hender | Dud.
|
| Mar 10 2005 02:41:22:933PM | 1050310013 | T.C. Hender | Definite locked mode at 0.925sec. Density a bit low nl_04=0.81e20. Acoil current= 2kA -Btop +Dbot +Gtop -Jbot. |
| Mar 10 2005 03:15:32:260PM | 1050310014 | Steve Wukitch | 014 NTP |
| Mar 10 2005 03:29:05:790PM | 1050310015 | Steve Wukitch | 015 5.4 T, Ip=0.8 MA, nl_04->0.8 D: 0.5 MW [0.6,.9]sec E: 0.8 MW [1.2,1.5]sec J: 0.6 MW [.9,1.2]sec result: plasma D: ran E: ran 1 fault J: ran max faults next shot: retune |
| Mar 10 2005 03:43:09:620PM | 1050310016 | Steve Wukitch | 016 5.4 T, Ip=0.8 MA, nl_04->0.8 D: 0.8 MW [0.6,.9]sec E: 1.0 MW [1.2,1.5]sec J: 1.0 MW [.9,1.2]sec result: plasma D: ran 2 faults E: ran J: ran max faults |
| Mar 10 2005 03:53:18:947PM | 1050310017 | Steve Wukitch | 017 NTP |
| Mar 10 2005 04:30:19:150PM | 1050310019 | Steve Wukitch | 019 5.4 T, Ip=0.8 MA, nl_04->0.8 D: 1.25 MW [0.6,1]sec E: 1.25 MW [0.6,1]sec J: 1.0 MW [1,1.5]sec result: plasma D: ran 6 faults E: ran 2 faults J: ran max faults (ran separate) |
| Mar 10 2005 05:07:05:197PM | 1050310022 | Steve Wukitch | 022 5.4 T, Ip=0.8 MA, nl_04->0.8 D: 1.25 MW [0.6,1]sec E: 1.25 MW [0.6,1]sec J: 1.0 MW [1,1.5]sec result: plasma D: ran 4 faults E: ran J: ran max faults (ran separate) |
| Mar 10 2005 05:24:10:557PM | 1050310023 | Steve Wukitch | 023 5.4 T, Ip=0.8 MA, nl_04->0.8 D: 1.25 MW [0.6,1]sec E: 1.25 MW [0.6,1]sec J: 1.0 MW [1,1.5]sec result: plasma D: ran 6 faults E: ran 3 faults J: ran max faults (improving - conditioning issue) |
| Mar 10 2005 05:33:58:590PM | 1050310024 | Steve Wukitch | 024 5.4 T, Ip=0.8 MA, nl_04->0.8 D: 1.25 MW [0.6,1]sec E: 1.25 MW [0.6,1]sec J: 1.0 MW [1,1.5]sec result: plasma D: ran 3 faults E: ran 8 faults J: ran max faults - failed particularly badly during overlap |
| Mar 10 2005 05:52:16:527PM | 1050310025 | Steve Wukitch | 025 5.4 T, Ip=0.8 MA, nl_04->0.8 D: 1.25 MW [0.6,1]sec E: 1.25 MW [0.6,1]sec J: 1.0 MW [1,1.5]sec result: plasma D: ran E: ran max faults J: ran max faults - #3 xbarred after shot - tube arc change phase feedback to wideband and add length of cable to adjust starting phase |
| Mar 10 2005 05:59:08:290PM | 1050310026 | Steve Wukitch | 026 5.4 T, Ip=0.8 MA, nl_04->0.8 D: 1.25 MW [0.6,1]sec E: 1.25 MW [0.6,1]sec J: 1.0 MW [1,1.5]sec result: plasma D: ran 4 faults E: ran 4 faults J: ran max faults - need to phase lock |
| Physics Operator Comments | |||
| Mar 10 2005 10:46:41:290AM | 1050310001 | Joseph Snipes | Shot 1: Copied segment 2 from 1040413029 and changed the TF current to 110100 A for 4 T flattop after breakdown and Ip to 0.81 MA flattop and nl04 to 1 x 10^20 m^-2. Changed the Ip predictor to ROG_FG and -70000 offset. Changed density feedback to nl04. Turned off the previous segment 3 and turned on segment 2. Copied segment 1 from 1050303025 and increased prepuff by 1 ms to 20 ms duration. Zeroed out A-coil waveform. Removed pre-programmed gas from pulse gas 3 in segment 2. Zeroed out pulse gas 2. Fizzle! |
| Mar 10 2005 11:02:28:807AM | 1050310002 | Joseph Snipes | Shot 2: Strange startup for shot 1. Copied 1050301004 segment 1 to attempt to improve the startup. Got plasma. Lots of hard x rays. |
| Mar 10 2005 11:16:56:527AM | 1050310002 | Joseph Snipes | Shot 3: Increased EF4 current from -1355 to -1340 A. Increased prepuff by 2 ms to 22 ms duration. Changed RCUR by -1.5 mm early and -2.5 mm at 1.5 s to attempt to increase the outer gap and keep it flat at 1.2 cm. Increased nl04 to 1.4 x 10^20 m^-2. Good shot. Disrupted at 1.3 s. |
| Mar 10 2005 11:29:29:010AM | 1050310004 | Joseph Snipes | Shot 4: Raised Br0 from -2.5 mT to -2.0 mT. Increased prepuff by another 2 ms to 24 ms duration. Reduced nl04 to 1.2 x 10^20 m^-2. Good shot. Disrupted at 1.45 s. |
| Mar 10 2005 11:46:25:430AM | 1050310004 | Joseph Snipes | Shot 5: Turned on A-coils from 0.8 to 1.5 s at 2500 A. Good shot. Disrupted at 1.35 s. |
| Mar 10 2005 12:25:22:947PM | 1050310006 | Joseph Snipes | Shot 6: OH1 fault on shot 5. Reduced OH1 and OH2 current limits back to [-27, +27] kA. Increased A-coil current to 4 kA. Fizzle! |
| Mar 10 2005 12:36:13:120PM | 1050310007 | Joseph Snipes | Shot 7: Reduced prepuff by 4 ms to 20 ms duration. Disrupted at 0.625 s. |
| Mar 10 2005 12:58:24:743PM | 1050310008 | Joseph Snipes | Shot 8: Repeat. Fizzle! |
| Mar 10 2005 01:45:33:713PM | 1050310008 | Joseph Snipes | Shot 9: Dropped EF4 from -1340 to -1360 A. Reduced prepuff by 2 ms to 18 ms duration. Got plasma, but the startup still bounces. |
| Mar 10 2005 01:27:27:480PM | 1050310009 | Joseph Snipes | Shot 9: Set EF4 to -1350 A. Increased prepuff by 1 ms to 19 ms duration. Reduced Br0 by 0.5 mT to -1.5 mT. Lowered nl04 to 1 x 10^20 m^-2. Good shot. |
| Mar 10 2005 01:56:19:620PM | 1050310010 | Joseph Snipes | Shot 10: Repeat. Good shot. Disrupted at 1.48 s. |
| Mar 10 2005 02:08:35:900PM | 1050310011 | Joseph Snipes | Shot 11: Dropped A-coil current to 2500 A. Good shot. |
| Mar 10 2005 02:22:06:650PM | 1050310012 | Joseph Snipes | Shot 12: Raised Br0 by 0.5 mT to -1 mT. Raised EF4 by 15 A to -1335 A. Dud. |
| Mar 10 2005 02:35:23:760PM | 1050310013 | Joseph Snipes | Shot 13: Apparently, that did not work. Reloaded segment 1 from shot 1050310011. Runaways in the startup. Plasma disrputed at 1.36 s. |
| Mar 10 2005 03:01:29:447PM | 1050310014 | Joseph Snipes | Shot 14: RF conditioning run. Copied segment 2 from shot 1050309021 at 5.4 T. Set nl04 to 0.8 x 10^20 m^-2. Set RCUR offset to 1500. Increased prepuff to 20 ms duration. Put 2 psi Ar into B side lower and enabled it for John Rice. Opened the Z-bolo shutter. |
| Mar 10 2005 03:09:18:027PM | 1050310014 | Joseph Snipes | Shot 14: Fizzle! |
| Mar 10 2005 03:15:01:557PM | 1050310014 | Joseph Snipes | Shot 15: Dropped prepuff by 2 ms to 18 ms duration. Increased EF4 by 5 A to -1345 A. |
| Mar 10 2005 03:21:35:040PM | 1050310015 | Joseph Snipes | Shot 15: Dropped prepuff by 2 ms to 18 ms duration. Increased EF4 by 5 A to -1345 A. Good shot but with runaways in the startup. |
| Mar 10 2005 03:41:33:713PM | 1050310016 | Joseph Snipes | Shot 16: Reduced RCUR offset in segment 1 to 750. Increased prepuff by 2 ms to 20 ms duration. Set RCUR straight across in segment 2 to 0.658 m to attempt to maintain a constant outer gap. Good shot. The startup looks the best all day. |
| Mar 10 2005 03:53:10:010PM | 1050310017 | Joseph Snipes | Shot 17: NINJA puffing D2 at 1.2 s. Fizzle. |
| Mar 10 2005 04:05:42:400PM | 1050310018 | Joseph Snipes | Shot 18: Reduced Br0 by 0.5 mT to -2 mT. Got plasma but again with lots of runaways. |
| Mar 10 2005 04:21:27:573PM | 1050310019 | Joseph Snipes | Shot 19: Returned RCUR offset to 1000 in segment 1 and increased prepuff by 2 ms to 23 ms duration. Good shot. Startup looks OK, but with a hesitation. |
| Mar 10 2005 04:37:26:183PM | 1050310020 | Joseph Snipes | Shot 20: Computer system failure. No power, no data. |
| Mar 10 2005 04:55:01:447PM | 1050310021 | Joseph Snipes | Shot 21: Cycle test. |
| Mar 10 2005 05:05:02:557PM | 1050310022 | Joseph Snipes | Shot 22: Finally got plasma again but with a lot of hard x rays. |
| Mar 10 2005 05:21:33:540PM | 1050310023 | Joseph Snipes | Shot 23: Changed RCUR offset to 500. Good shot. Startup looks worse with a hesitation in the current rise. |
| Mar 10 2005 05:33:20:590PM | 1050310024 | Joseph Snipes | Shot 24: Changed RCUR offset to 1500. Good shot. Startup looks better with no bounce though Bz still rises rather slowly. |
| Mar 10 2005 05:46:04:620PM | 1050310025 | Joseph Snipes | Shot 25: Repeat. Good shot. Startup did not bounce. Still has a slow current rise though. |
| Mar 10 2005 05:57:42:963PM | 1050310026 | Joseph Snipes | Shot 26: Repeat. Good shot. Startup looks similar to the previous two shots. |
| Mar 10 2005 06:08:42:620PM | 1050310026 | Joseph Snipes | Summary: The first part of the run on error field identity with JET did not go all that well in that few locked modes were found. The ICRF injected a few MW and some brief H-modes were driven. There were also some very short initial LHCD pulses at 0.5 s that were particularly visible during a fizzle in front of the LH grill on the camera view. Overall, the machine ran pretty well. There were difficulties with the startup and a number of shots had hard x rays early on. It seems that the RCUR offset should be set to at least 1500 and perhaps even a bit higher might improve the startup. The last three shots had the offset at 1500 and their current rises were a bit slow but otherwise good. Out of 26 shots, there were 5 fizzles, two computer system tests, one dud, and 18 plasmas. |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 10:45:02:620AM | Plasma | Ok | |
| 2 | 11:00:38:260AM | Plasma | Ok | |
| 3 | 11:14:05:417AM | Plasma | Ok | |
| 4 | 11:27:10:947AM | Plasma | Ok | |
| 5 | 11:41:02:277AM | Plasma | Bad | OH1_1 SCR Not Conducting Flt |
| 6 | 11:59:05:883AM | Plasma | Ok | |
| 7 | 12:34:12:207PM | Plasma | Ok | |
| 8 | 12:56:50:510PM | Plasma | Ok | |
| 9 | 01:09:35:573PM | Plasma | Ok | |
| 10 | 01:25:37:073PM | Plasma | Ok | |
| 11 | 02:06:10:650PM | Plasma | Ok | |
| 12 | 02:20:31:027PM | Plasma | Ok | |
| 13 | 02:33:01:730PM | Plasma | Ok | |
| 14 | 03:07:07:150PM | Plasma | Ok | |
| 15 | 03:19:53:027PM | Plasma | Ok | |
| 16 | 03:36:55:167PM | Plasma | Ok | |
| 17 | 03:51:28:057PM | Plasma | Ok | |
| 18 | 04:03:57:323PM | Plasma | Ok | |
| 19 | 04:18:41:277PM | Plasma | Ok | |
| 20 | 04:32:18:933PM | Test | Bad | |
| 21 | 04:50:36:993PM | Plasma | Bad | Computer problems |
| 22 | 05:03:16:947PM | Plasma | Ok | |
| 23 | 05:17:03:887PM | Plasma | Ok | |
| 24 | 05:29:56:277PM | Plasma | Ok | |
| 25 | 05:42:28:057PM | Plasma | Ok | |
| 26 | 05:54:49:777PM | Plasma | Ok | |