| Miniproposals | ||||||||||
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| Operators | |
| Session leader(s): | Jason Sears |
| Physics operator(s): | Joseph Snipes |
| Engineering operator(s): | Andy Pfeiffer,Ed Fitzgerald,Gary Dekow |
| Engineering Operator Run Comment |
| Run Plan for 1051109 MP 404a Parametric Dependence of Moderate n Alfven |
| Session Leader Plans |
| Entered: Nov 8 2005 05:35:29:067PM |
| Author: Jason Sears |
| Session Leader Run Plan for 1051109 MP 404a Parametric Dependence of Moderate n Alfven Eigenmode Damping Rates
Session Leader: J Sears Physics Operator: J Snipes This Active MHD run will continue parametric comparison of nu* vs the Alfven eigenmode damping rate by varying density. We will begin with 1050812005, which is an inner wall limited elongated plasma with nebar = 1.8 m^-3; kappa = 1.6; delta = 0.35; Ip = 0.8 MA and B_T = 5.4T. Antennas will be driven in phase; they will sweep a 200 kHz amplitude (peak to peak) at 1.5 MHz/s about the calculated TAE frequency. From shot to shot the density will be scanned from nebar = 0.5 x 10^20 m^-3 to 4 x 10^20 m^-3 with three shots at each increment to drive TAE's at the q=1, 1.5 and 2 surfaces. If time allows, we will invert the phase of one antenna to look at the effect of the change in poloidal mode structure on the signal and damping rate for representative low, mid and high-density shots from earlier in the day. ICRF will not be required for this run. Key diagnostics are magnetics, density and Zeff. |
| Physics Operators Plans |
| Entered: Nov 8 2005 04:05:47:910PM |
| Author: Steve Wolfe |
Engineering setup and physop plan for Wed. 11/9/2005 Joe Snipes will be the Physop for this run, but he is out today so I'm entering the setup information. If he cannot make it tomorrow I'll substitute. The scheduled experiment is MP#404a "Alfven wave damping...", with Jason Sears as Session Leader. This experiment requires the Active MHD Spectroscopy amplifier to be working, and as this is being written there seems to be a problem with this hardware. Jason will be working to correct the problem tonight. If he is unsuccessful then the run will revert to MP#355 (ICRF Conditioning). Engineering setup: ------------------ Overnight ECDC and bake at 60C Run begins at 09:00 (Lockup at 08:30) and ends at 17:00 Power systems as on 1050812005 (inner wall limited, 800kA, 5.4T) A-coil configuration: normal [+Dtop -Dbot -Jtop +Jbot] and enabled. Gas Setup: fill B-Top with 6 psi D2 Hybrid enabled (PG4) fill B-side lower with 1 psi Ar + 2 psi Ne Hybrid DISABLED (PG1) leave B-side upper as is Hybrid disabled (PG2) fill B-main (C-side) with 40 psi D2 Hybrid enabled (PG3) No NINJA required Enable the following gate valves and shutters, assuming no vacuum problems: ECE, VUV, Z-bolo shutters ICRF transmitters in RUN-ON by 8:30. ICRF can piggyback all day if they don't end up being the primary experiment. PCS setup: ----------- Load segment 2 from 1050812005 (or other shot if specified by SL). Recalculate magnetics predictors to account for change in BP loop last week. Run Plan: See Session Leader's posting under SL_PLAN |
| Session Leader Summaries |
| Entered: Nov 10 2005 09:27:47:110AM |
| Author: Jason Sears |
| We had hoped to scan nl_04/1e20m^-3 from 0.3 to 2.2. After a two hour pause to fix a power supply, we continued with the scan but we seemed to hit a density limit around 1.2e20m^-3. Then most shots were fizzles or disrupted around 0.7s, cause unknown.
Successful shots today that contributed to a density scan were: shot nl_04 nebar qAE resonances ---- ----- ----- --- ---------- 002 1.0 2.0 1.5 @0.6s 003 1.0 2.0 1.5 good 004 0.6 1.1 1.5 @1.65s 005 0.6 1.0 1.5 rough 008 0.4 0.6 1.5 rough 009 0.6 1.0 2.0 rough 010 0.4 0.6 2.0 rough 011 0.6 1.3 2.0 rough 013 0.6 1.2 2.0 rough 014 0.75 1.4 2.0 @1.2s 015 0.8 1.4 1.5 good 017 1.0 1.8 2.0 @1.1s For the next run of this MP, the amplifier should be made able to drive frequencies up to 812 kHz so we can excite q=1 modes. We could also reduce B_T to make this easier. It would also be good to have the PCI diagnostic online. |
| Physics Operator Summaries |
| Entered: Nov 9 2005 05:10:23:193PM |
| Author: Joseph Snipes |
| There were a few problems running the machine today. Shot 1 had a problem with OH1 that prevented breakdown. Shot 2 ran but had the EF2_BY_EF4 wire programmed incorrectly due to physop error. Then, shots 3 - 5 ran fine, but shot 6 blew a number of fuses in OH2 early so that we got no breakdown. This resulted in more than a two hour delay. Shot 7 was an OH test shot. Then, we finally got on with the physics program and managed to get a limited density scan. But, we were plagued with runaways from early in the pulse for many shots and late in the day with fizzles and disruptions when we went to higher density. The density was varied from nl04 = 3.5 x 10^19 m^-2 to 1.4 x 10^20 m^-2. The low end had runaways and the high end had radiative disruptions. Perhaps, the Ar+Ne puffing helped radiate the power and led to disruptions at an otherwise lower than normal density, but I did not turn it off to check. Still, there should be some useful data at a few different densities to check the TAE damping rate vs collisionality. The scorecard was: Shot,Duration(s),Ipmax(MA),Result Shot,Duration(s),Ipmax,Result | 01 0.000 0.019 PSfault | 02 1.904 0.797 Plasma | | 03 1.916 0.800 Plasma | 04 1.965 0.801 Plasma | | 05 1.964 0.802 Plasma | 06 0.000 0.024 PSfault | | 07 0.000 0.004 PStest | 08 1.592 0.796 Plasma | | 09 1.949 0.801 Plasma | 10 1.611 0.796 Plasma | | 11 1.938 0.800 Plasma | 12 0.000 0.037 Fizzle | | 13 1.898 0.801 Plasma | 14 1.809 0.799 Plasma | | 15 1.897 0.802 Plasma | 16 0.000 0.024 Fizzle | | 17 1.739 0.799 Plasma | 18 0.000 0.023 Fizzle | | 19 0.727 0.867 Plasma | 20 0.000 0.024 Fizzle | | 21 0.000 0.023 Fizzle | 22 0.686 0.875 Plasma | | 23 0.000 0.024 Fizzle | 24 0.691 0.850 Plasma | Date 1051109: 24 shots. 15 plasmas. 5 fizzles. 2 power supply faults, 1 power supply test Total plasma duration: 24.29 s |
| Session Leader Comments | |||
| Nov 9 2005 05:15:33:990PM | Jason Sears | Successful shots today that contributed to a density scan were:
shot nl_04 nebar qAE resonances ---- ----- ----- --- ---------- 002 1.0 2.0 1.5 @0.6s 003 1.0 2.0 1.5 good 004 0.6 1.1 1.5 @1.65s 005 0.6 1.0 1.5 rough 008 0.4 0.6 1.5 rough 009 0.6 1.0 2.0 rough 010 0.4 0.6 2.0 rough 011 0.6 1.3 2.0 rough 013 0.6 1.2 2.0 rough 014 0.75 1.4 2.0 @1.2s 015 0.8 1.4 1.5 good 017 1.0 1.8 2.0 @1.1s We had hoped to scan nl_04/1e20m^-3 from 0.3 to 2.2, but we seemed to hit a density limit around 1.2e20m^-3. There was also something causing disruptions around 0.7s. For the next run of this MP, the amplifier should be made able to drive frequencies up to 812 kHz so we can excite q=1 modes. We could also reduce B_T to make this easier. It would also be good to have the PCI diagnostic online. | |
| Nov 9 2005 10:33:52:140AM | 1051109003 | Jason Sears | Shots 002 and 003 repeat reference shot conditions before attempting low density.
nebar=2e20. |
| Nov 9 2005 10:01:22:970AM | 1051109004 | Jason Sears | Successful attempt at ne=3e19. |
| Nov 9 2005 10:06:17:390AM | 1051109004 | Jason Sears | Actual density achieved was nebar=1e20. |
| Nov 9 2005 10:27:16:687AM | 1051109005 | Jason Sears | Repeat 004; looking for lower density as the walls evolve gas.
nebar~1e20 still. |
| Nov 9 2005 04:09:44:157PM | 1051109006 | Jason Sears | Dud.
2 hour pause to fix a power supply. Class from 1pm-2:30pm. Returned in time for shot 16. |
| Nov 9 2005 01:28:26:907PM | 1051109009 | Joseph Snipes | Shot 9: I'm taking over as session leader for Jason while he is at his Transport class. Repeat with q=2 for the TAE frequency. Good shot. |
| Nov 9 2005 01:43:10:780PM | 1051109010 | Joseph Snipes | Shot 9: Try again with q=2 for the TAE frequency to get a lower density. Got down to nearly 3 x 10^19 m^-2. |
| Nov 9 2005 02:00:40:343PM | 1051109011 | Joseph Snipes | Shot 11: Try again with q=2 for the TAE frequency at 5 x 10^19 m^-2. Density stayed above 6 x 10^19 m^-2. |
| Nov 9 2005 02:38:29:470PM | 1051109014 | Joseph Snipes | Shot 14: Increase nl04 to 7 x 10^19 m^-2 staying at q=2. Good shot. |
| Nov 9 2005 02:54:20:420PM | 1051109015 | Joseph Snipes | Shot 15: Set q=1.5 for TAE frequency. Good shot. |
| Nov 9 2005 04:10:00:313PM | 1051109016 | Jason Sears | Fizzle |
| Nov 9 2005 03:24:02:937PM | 1051109017 | Jason Sears | Good shot: nl_04=1; qAE=2.0. |
| Nov 9 2005 03:38:00:470PM | 1051109018 | Jason Sears | Fizzle |
| Nov 9 2005 04:05:30:187PM | 1051109019 | Jason Sears | Disrupted at 0.7s, so we will retry this one.
q=1.5; attempted nl_04=1.4, achieved briefly before disruption. |
| Nov 9 2005 04:06:57:453PM | 1051109020 | Jason Sears | Fizzle |
| Nov 9 2005 04:15:11:093PM | 1051109021 | Jason Sears | Fizzle |
| Nov 9 2005 04:34:17:267PM | 1051109022 | Jason Sears | Disrupted at 0.68s. |
| Nov 9 2005 04:54:58:000PM | 1051109023 | Jason Sears | Fizzle |
| Nov 9 2005 05:16:38:613PM | 1051109024 | Jason Sears | Disrupted at 0.68s |
| Physics Operator Comments | |||
| Nov 9 2005 09:07:45:047AM | 1051109001 | Joseph Snipes | Shot 1: Loaded segment 2 from 1050812005 and called all predictors that use BP coils to correct for BP16_JK which had previously been BP16_DE. Starting with nl04 = 1 x 10^20 m^-2. Kept segment 1 from what was in the model file except for a reduced pre-puff now set to 28 ms duration at Wolfe's suggestion. Dud! Problem with OH1. |
| Nov 9 2005 10:07:01:390AM | 1051109002 | Joseph Snipes | Shot 2: Shot ran full length, but I had incorrectly called the predictor for E2_BY_EF4 and it zeroed out the gains leaving no control. So, the plasma shape and position was not well controlled. It ran surprisingly well considering, but is not what we wanted. |
| Nov 9 2005 10:07:16:063AM | 1051109003 | Joseph Snipes | Shot 3: Lowered nl04 to 3 x 10^19 m^-2 and increased prepuff to 33 ms duration. Good shot but only got down to 6 x 10^-19 m^-2. |
| Nov 9 2005 10:30:50:750AM | 1051109004 | Joseph Snipes | Shot 4: Lowered Br0 by 0.5 mT to -0.5 mT. Added A-coil feedback on wire 11 B21_PROJ and zeroed out A-coil current. Set integrator C to start at 0.3 s. Hard x rays saturated until 0.35 s. Density came down a little. |
| Nov 9 2005 10:31:43:797AM | 1051109005 | Joseph Snipes | Shot 5: Repeat to get lower density. |
| Nov 9 2005 10:32:51:703AM | 1051109006 | Joseph Snipes | Shot 6: Increased pre-puff to 40 ms duration. Crowbar on OH2 early. Dud! |
| Nov 9 2005 11:05:08:890AM | 1051109006 | Joseph Snipes | There will be at least a one hour delay to repair the OH2U power supply. |
| Nov 9 2005 12:51:26:970PM | 1051109007 | Joseph Snipes | Shot 7: OH1 and OH2 test shot. |
| Nov 9 2005 01:13:27:407PM | 1051109008 | Joseph Snipes | Shot 8: Add Ar+Ne puff from 0.3 s for 50 ms duration. DNB turned on for 50 ms duration at 1.0 s. ICRF has been piggybacking from 1.3 to 1.5 s for tuning from the beginning of the run. Good shot except for a lot of runaways. |
| Nov 9 2005 01:37:26:890PM | 1051109009 | Joseph Snipes | Shot 9: Increased prepuff to 44 ms duration. Good shot without many runaways, but the density stayed up to nearly 6 x 10^19 m^-2. Brian was injecting the F-port scanning probe three times as well that may have increased the density. |
| Nov 9 2005 01:42:36:250PM | 1051109010 | Joseph Snipes | Shot 10: Turned off the scanning probe and reduced the Ar+Ne puff to 30 ms duration from 0.35 to 0.38 s. Decent shot with some runaways. |
| Nov 9 2005 02:18:23:593PM | 1051109011 | Joseph Snipes | Shot 11: Increase pre-puff to 49 ms duration. Increase nl04 to 5 x 10^19 m^-2. Return Ar+Ne puff to 50 ms duration. Good shot but density did not get low enough. |
| Nov 9 2005 02:18:45:670PM | 1051109012 | Joseph Snipes | Shot 12: Reduce nl04 before 0.5 s to 4 x 10^19 m^-2 try to get lower density. Fizzle! |
| Nov 9 2005 02:33:16:860PM | 1051109013 | Joseph Snipes | Shot 13: Reduce pre-puff by 4 ms to 45 ms duration. Good shot. |
| Nov 9 2005 02:54:22:920PM | 1051109015 | Joseph Snipes | Shot 15: Repeat. Good shot. |
| Nov 9 2005 03:07:44:873PM | 1051109016 | Joseph Snipes | Shot 16: Increased EF4 current by 10 A to -1320 A. Increased nl04 to 1 x 10^20 m^-2. Fizzle! |
| Nov 9 2005 03:29:04:610PM | 1051109017 | Joseph Snipes | Shot 17: Reduced EF4 current by 15 A to -1335 A. nl04 set to 1 x 10^20 m^-2. Good shot but it had runaways from early on. |
| Nov 9 2005 03:36:34:437PM | 1051109018 | Joseph Snipes | Shot 18: Disabled the DNB gatevalve. Increased nl04 to 1.4 x 10^20 m^-2. Fizzle! |
| Nov 9 2005 04:01:45:813PM | 1051109019 | Joseph Snipes | Shot 19: Reduced pre-puff by 5 ms to 40 ms duration. Disrupted at 0.72 s, which was right at the same time that there was a large impurity injection on shot 17. |
| Nov 9 2005 04:02:17:983PM | 1051109020 | Joseph Snipes | Shot 20: Repeat. Fizzle. |
| Nov 9 2005 04:15:01:920PM | 1051109021 | Joseph Snipes | Shot 21: Reduced pre-puff by 5 ms to 35 ms duration. Fizzle! |
| Nov 9 2005 04:30:41:030PM | 1051109022 | Joseph Snipes | Shot 22: BZ0 jumped up at breakdown on shot 21. Reduced EF4 by 15 A to -1350 A. Increased Br0 by 0.3 mT to -0.2 mT. Got plasma but it disrupted again at 0.68 s. |
| Nov 9 2005 04:43:27:280PM | 1051109023 | Joseph Snipes | Shot 23: Reduced nl04 to 1.2 x 10^20 m^-2. Fizzle! |
| Nov 9 2005 04:58:14:840PM | 1051109024 | Joseph Snipes | Shot 24: Reduced pre-puff by 2 ms to 33 ms duration. One more time . . . now with nl04 = 1.2 x 10^20 m^-2. Disrupted at 0.68 s again. |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 09:04:32:843AM | Plasma | Ok | |
| 2 | 09:24:59:657AM | Plasma | Ok | |
| 3 | 09:42:22:237AM | Plasma | Ok | |
| 4 | 09:58:15:890AM | Plasma | Ok | |
| 5 | 10:13:54:843AM | Plasma | Ok | |
| 6 | 10:27:11:797AM | Plasma | Bad | OH2U Type 1 Flt |
| 7 | 12:52:50:797PM | Test | Ok | OH2U Power Test |
| 8 | 01:06:52:390PM | Plasma | Ok | |
| 9 | 01:24:22:407PM | Plasma | Ok | |
| 10 | 01:37:54:750PM | Plasma | Ok | |
| 11 | 01:51:14:110PM | Plasma | Ok | |
| 12 | 02:04:34:970PM | Plasma | Ok | |
| 13 | 02:18:21:470PM | Plasma | Ok | |
| 14 | 02:33:57:940PM | Plasma | Ok | |
| 15 | 02:50:22:373PM | Plasma | Ok | |
| 16 | 03:04:49:830PM | Plasma | Ok | |
| 17 | 03:18:37:250PM | Plasma | Ok | |
| 18 | 03:32:41:703PM | Plasma | Ok | |
| 19 | 03:46:32:220PM | Plasma | Ok | |
| 20 | 03:59:39:000PM | Plasma | Ok | |
| 21 | 04:13:00:873PM | Plasma | Ok | |
| 22 | 04:26:24:047PM | Plasma | Ok | |
| 23 | 04:41:29:220PM | Plasma | Ok | |
| 24 | 04:54:40:937PM | Plasma | Ok | |