| Miniproposals | ||||||||||
|
| Operators | |
| Session leader(s): | Joseph Snipes |
| Physics operator(s): | Robert Granetz |
| Engineering operator(s): | Gary Dekow |
| Engineering Operator Run Comment |
| MP404a - AE damping |
| Session Leader Plans |
| Entered: Mar 8 2006 01:17:34:623PM |
| Author: Joseph Snipes |
| MP404a - AE damping Standard gas setup and ECDC in deuterium before the run. ICRF will be allowed to condition near the end of the discharge from say 1.3 to 1.5 s to see if good heating can be obtained for later use toward the end of the run. Run Plan: Begin with segment 2 from shot 1050615011 a near double null inner wall limited plasma with Ip = 0.8 MA except change the TF to be constant at 5.4 T out to 1.5 s. The first 10 shots will be a density scan starting at nl04 = 1 x 10^20 m^-2 and then increase the density to 1.2 x 10^20 m^-2, then 1.4 x 10^20 m^-2. If successful, we may go on to 1.6 x 10^20 m^-2. Then, we will program 0.5 x 10^20 m^-2 and run several shots to reach that low a density if possible. If it is reached within 7 shots, we may program 0.4 x 10^20 m^2 to end the density scan. The next 10 shots will be dedicated to an elongation scan by decreasing the elongation quickly for a few shots down to kappa = 1.1 or so if possible, checking the mode number to see if it remains the same shot to shot. If the mode remains constant, we fill in the elongation scan with intermediate values and f possible, we may also increase kappa to 1.8. If the ICRF is heating and can drive a fast ion tail, we will attempt some ICRF discharges with 2.5 MW to look first for unstable TAEs then reduce the power shot to shot in 0.5 MW steps for five shots. If ICRF is not heating well, we will do phase and frequency scans of the active MHD for previously identified good shots. |
| Physics Operators Plans |
| Entered: Mar 8 2006 04:31:19:253PM |
| Author: Robert Granetz |
Engineering setup for Thursday 09 Mar 2006
MP 404a: Alfven Eigenmode damping
Session leader: J. Snipes, A. Fasoli
Physics operator: R. Granetz
Overnight ECDC in deuterium, and bake at 60 C.
Run begins at 09:00 and ends at 17:00.
Power systems as on 1050615011.
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 for this run.
Enable the following gate valves and shutters, assuming no vacuum problems:
ECE, VUV, Z-bolo shutters
Torvac setup: Gate valves open
Key diagnostics: PCI, Mirnov coils (appropriate fast sampling windows)
-------------------------------------------------------------------------------
ICRF Setup: J in run-on by 08:30. ICRF will be allowed to condition near
the end of the discharge from say 1.3 to 1.5 s to see if good
heating can be obtained for later use toward the end of the
run.
-------------------------------------------------------------------------------
Run plan: Begin with segment 2 from shot 1050615011 a near double null
inner wall limited plasma with Ip = 0.8 MA except change the TF
to be constant at 5.4 T out to 1.5 s. The first 10 shots will be
a density scan starting at nl04 = 1 x 10^20 m^-2 and then
increase the density to 1.2 x 10^20 m^-2, then 1.4 x 10^20 m^-2.
If successful, we may go on to 1.6 x 10^20 m^-2. Then, we will
program 0.5 x 10^20 m^-2 and run several shots to reach that low
a density if possible. If it is reached within 7 shots, we may
program 0.4 x 10^20 m^2 to end the density scan. The next 10
shots will be dedicated to an elongation scan by decreasing the
elongation quickly for a few shots down to kappa = 1.1 or so if
possible, checking the mode number to see if it remains the same
shot to shot. If the mode remains constant, we fill in the
elongation scan with intermediate values and if possible, we may
also increase kappa to 1.8. If the ICRF is heating and can drive
a fast ion tail, we will attempt some ICRF discharges with 2.5 MW
to look first for unstable TAEs then reduce the power shot to
shot in 0.5 MW steps for five shots. If ICRF is not heating
well, we will do phase and frequency scans of the active MHD for
previously identified good shots.
|
| Session Leader Summaries |
| Entered: Mar 9 2006 08:26:25:630PM |
| Author: Joseph Snipes |
| The run had a slow start first because there were problems yesterday with the gas fueling valve and so tests of the gas fueling started the run. Then, there was a TF scanner test. Then, the first plasma attempt failed to have gas for some reason. Then, it turned out that liquid nitrogen was dripping on the TCI and disturbing the measurement. So, we had about a 2 hour delay to fix the TCI. Finally, we got a plasma on shot 5. The active MHD amplifiers worked well and a number of AE resonances were found. The first few plasma shots were taken at the wrong frequency due to an inadvertent voltage divider in parallel with a filter on the VCO input. After that was resolved, we managed to scan density from nl04 = 1.5 x 10^20 m^-2 down to 0.75 x 10^20 m^-2. Then, we varied elongation from kappa = 1.6 down to kappa = 1.2 and then filled in several points in between. Since the ICRF was not yet conditioned, there were no attempts to use ICRF. Time also did not permit changing the antenna phase or doing more of a resonant q scan. The damping rates were found in the 2 - 3% range and n numbers between 3 and 10 were also estimated, though there was some difficulty getting clearly defined n numbers. Further analysis is required to determine if a clear scaling of the TAE damping rate with density or elongation can be determined for a particular n number. Overall, despite the long delays, we still managed to get some TAE damping results. We showed that the changes made to the cabling and amplifiers significantly improved the performance. Of the 14 plasmas produced, 11 of them will probably provide useful damping measurements. |
| Physics Operator Summaries |
| Entered: Mar 9 2006 05:04:26:910PM |
| Author: Robert Granetz |
Physics operator summary for Thursday 09 Mar 2006:
MP 404a: Alfven Eigenmode damping
Session leaders: J. Snipes, A. Fasoli
Physics operator: R. Granetz
We got the density scan done and did much of the elongation scan. There
was a very long delay at the beginning of the day to get the TCI
interferometer working after a lot of LN2 liquid and vapor at H-port bottom
badly affected the optics. (We really needed the TCI, both for the density
scan and for the active TAE frequency feedback, and so we couldn't switch
to z-meter control.) There were also numerous cell accesses to fix things
on the active MHD system. There were a number of fizzles and duds, which I
think is because we're still early in the campaign and the machine still
needs more conditioning. Once we got the first plasma (on shot 5), the
startup reliability was 14 out of 20.
Scorecard: 14 plasmas
4 duds (gas system failed on one shot)
4 fizzles
1 gas system tests
1 TF scanner tests
0 power supply tests
0 MDSplus cycle tests
--------------
Total: 24 shot cycles
|
| Session Leader Comments | |||
| Mar 9 2006 09:46:25:160AM | 1060309001 | Joseph Snipes | Shot 1: Begin with standard conditions to look for TAE resonances with a near double null inner wall limited plasma with Ip = 0.8 MA, BT = 5.4 T, and nl04 = 1 x 10^20 m^-2. Both active MHD antennas turned on. There seems to be a problem with the T_ABK pick-up coils that they have very low signal compared to test shots yesterday. No plasma gas test. |
| Mar 9 2006 09:47:07:427AM | 1060309002 | Joseph Snipes | Checked pick-up coil cables at the feedthroughs and at the rack and they all seem to be connected properly. |
| Mar 9 2006 09:47:56:100AM | 1060309003 | Joseph Snipes | Waiting for plasma . . . |
| Mar 9 2006 11:27:01:100AM | 1060309004 | Joseph Snipes | Waiting for plasma . . . |
| Mar 9 2006 01:31:46:287PM | 1060309005 | Joseph Snipes | Good shot with TAE frequency for q ~ 3 and nl04 = 1.2 x 10^20 m^-2. |
| Mar 9 2006 01:36:04:210PM | 1060309006 | Joseph Snipes | Good shot with TAE frequency for q ~ 3 and nl04 = 1.3 x 10^20 m^-2. |
| Mar 9 2006 01:15:07:927PM | 1060309008 | Joseph Snipes | The RC filter that Jason installed on the VCO input to the amplifier controller divided the voltage by about a factor of two meaning that the frequency we are driving is about a factor of 2 too low. So, the previous shots were effectively at q=3 rather than q=1.5. |
| Mar 9 2006 01:36:52:520PM | 1060309008 | Joseph Snipes | Good shot with TAE frequency for q ~ 3 and nl04 = 1.5 x 10^20 m^-2. |
| Mar 9 2006 01:38:35:473PM | 1060309009 | Joseph Snipes | The RC filter was removed and the noise on the VCO increased substantially, though the frequency is now correct for q=1.5 and nl04 = 1.5 x 10^20 m^-2. |
| Mar 9 2006 01:52:16:053PM | 1060309010 | Joseph Snipes | The RC filter was put back in place but the signal to the Aurora12 was removed. Good shot, but the frequency sweep is still noisy, so the filter did not do anything. This is a good plasma at q=1.5 and nl04 = 1.3 x 10^20 m^-2. |
| Mar 9 2006 02:17:50:363PM | 1060309012 | Joseph Snipes | Good shot with q=1.5 and nl04 = 1.0 x 10^20 m^-2. |
| Mar 9 2006 02:29:53:973PM | 1060309013 | Joseph Snipes | Reduced the constant multiplier from 1.0 to 0.9 on the f_TAE calculation in DPCS to center the frequency sweep on the EFIT calculated TAE frequency. Good shot at q=1.5 and nl04 = 0.9 x 10^20 m^-2. |
| Mar 9 2006 02:55:56:613PM | 1060309014 | Joseph Snipes | Increased the constant multiplier from 0.9 to 0.94 on the f_TAE calculation in DPCS to center the frequency sweep on the EFIT calculated TAE frequency. Good shot at q=1.5 and nl04 = 0.8 x 10^20 m^-2. |
| Mar 9 2006 03:07:12:660PM | 1060309015 | Joseph Snipes | Decreased the constant multiplier from 0.94 to 0.9 on the f_TAE calculation in DPCS to center the frequency sweep on the EFIT calculated TAE frequency. Good shot at q=1.5 and nl04 = 0.75 x 10^20 m^-2. |
| Mar 9 2006 03:19:42:833PM | 1060309016 | Joseph Snipes | Decreased the constant multiplier from 0.94 to 0.9 on the f_TAE calculation in DPCS to center the frequency sweep on the EFIT calculated TAE frequency. Good shot at q=1.5 and nl04 = 0.78 x 10^20 m^-2. The density increased rather than decreased for that shot. Try changing the shape instead. |
| Mar 9 2006 03:48:56:693PM | 1060309017 | Joseph Snipes | Changed elongation to 1.2. Disrupted after 1.5 s. nl04 = 1.2 x 10^20 m^-2 though I asked for 0.9 x 10^20 m^-2. |
| Mar 9 2006 03:53:25:537PM | 1060309018 | Joseph Snipes | Good shot at kappa = 1.2 until 1.2 s, then with a sweep in elongation up and down. nl04 = 0,9 x 10^20 m^-2 as requested. |
| Mar 9 2006 03:59:18:787PM | 1060309019 | Joseph Snipes | Fizzle! |
| Mar 9 2006 04:25:38:520PM | 1060309020 | Joseph Snipes | Good shot with kappa = 1.34 and nl04 = 0.9 x 10^20 m^-2. |
| Mar 9 2006 04:41:56:380PM | 1060309022 | Joseph Snipes | Good shot with kappa = 1.45 and nl04 = 0.9 x 10^20 m^-2. |
| Mar 9 2006 05:03:27:647PM | 1060309024 | Joseph Snipes | Dud! |
| Physics Operator Comments | |||
| Mar 9 2006 08:49:12:100AM | Robert Granetz | I had Bill Cochran set the TF invert time to 3.8 s and the fizzle delay for the TF to 2.5 s | |
| Mar 9 2006 09:17:41:630AM | Robert Granetz | The first shot will be a gas-only test of the new PG3 fueling valve that replaced the one that was malfunctioning yesterday. | |
| Mar 9 2006 09:03:57:240AM | 1060309001 | Robert Granetz | Shot 01 -- Test of new PG3 gas valve. Looks like it's working well. Big improvement over yesterday. Next shot: go for plasma (after a short cell access for Joe to check on something with the active MHD system). |
| Mar 9 2006 09:17:24:443AM | 1060309001 | Robert Granetz | Correction...the next shot will be another no-power shot to check out a problem with the TF scanner readings. |
| Mar 9 2006 09:24:58:897AM | 1060309002 | Robert Granetz | Shot 02 -- Test for TF scanner readings (no power) Next shot: plasma |
| Mar 9 2006 09:37:17:270AM | 1060309003 | Robert Granetz | Shot 03 -- Dud. No gas signals got to the PLC. Really strange, because shots 1 and 2 had normal gas. Apparently one of those rare random glitches with the gas system. Next shot: try for plasma again. |
| Mar 9 2006 10:44:27:193AM | 1060309003 | Robert Granetz | We're having a long delay while the interferometer problems are fixed. The problem is that a large amount of LN2 liquid and vapor was pouring all over the H-port area. |
| Mar 9 2006 11:31:24:100AM | 1060309004 | Robert Granetz | Shot 04 -- Dud. Got gas this time. Next shot: add 3 ms to pre-fill puff (to 24 ms), subtract 0.3 mT from Br0, add -10 amps to IC_EF4 |
| Mar 9 2006 11:52:41:100AM | 1060309005 | Robert Granetz | Shot 05 -- Plasma. Good shot. Made it most of the way into rampdown. nl_04=1.2e20 m-2. H/(H+D)=6% !! Can it really be that good? Inboard-limited, nearly double null. Next shot: Start density scan...raise nl_04 to 1.4 by programming the demand to be 1.2, based on this shot (05). Also decrease pre-fill pulse by 1 ms. |
| Mar 9 2006 12:22:57:613PM | 1060309006 | Robert Granetz | Shot 06 -- Plasma. Good shot. nl_04=1.3e20 m-2. H/(H+D)=6-7%. There were some hard x-rays early on. Startup bounced out. Nest shot: raise nl_04 programming to 1.4e20 m-2. Add 2 ms to prefill. |
| Mar 9 2006 12:32:19:583PM | 1060309007 | Robert Granetz | Shot 07 -- Fizzle. Gas pressure looks high. Next shot: take the 2 ms back off the pre-fill. |
| Mar 9 2006 01:01:29:817PM | 1060309008 | Robert Granetz | Shot 08 -- Plasma. Good shot. nl_04=1.56e20 m-2. Lots of hard x-rays early in the shot. Next shot: repeat, no changes |
| Mar 9 2006 01:34:23:113PM | 1060309009 | Robert Granetz | Shot 09 -- Plasma. Good shot. nl_04=1.5e20 m-2. No hard x-rays. Good startup. Next shot: reduce nl_04 by 0.2e20 m-2 |
| Mar 9 2006 01:48:34:053PM | 1060309010 | Robert Granetz | Shot 10 -- Plasma. Good shot. nl_04=1.3e20 m-2. Next shot: Reduce nl_04 another 0.2e20 m-2. Also turn off the density hard after t=1.5 s to try and avoid the late rampdown disruption. |
| Mar 9 2006 02:02:32:583PM | 1060309011 | Robert Granetz | Shot 11 -- Dud. Gas and fields look fine. Next shot: substract 1 ms from pre-fill, add 0.1 mT to Br0, add 5 amps to IC_EF4 |
| Mar 9 2006 02:14:07:770PM | 1060309012 | Robert Granetz | Shot 12 -- Plasma. Good shot. nl_04=1.0e20 m-2. Got a little farther in the rampdown. Good startup. Next shot: Lower nl_04 to 0.8e20 m-2. |
| Mar 9 2006 02:30:39:397PM | 1060309013 | Robert Granetz | Shot 13 -- Plasma. Good shot. nl_04=0.9e20 m-2. Current ramped all the way down, no doubt because the density was lower. Beautiful startup. Next shot: Reduce nl_04 to 0.6e20 m-2 |
| Mar 9 2006 03:09:58:600PM | 1060309014 | Robert Granetz | Shot 14 -- Plasma. Good shot. nl_04=0.75e20 m-2, which is a little higher than we wanted. Next shot: decrease pg3 pregrammed voltage to zero and hope for lower density. |
| Mar 9 2006 03:11:29:647PM | 1060309015 | Robert Granetz | Shot 15 -- Plasma. Good shot. Density is still higher than the 0.6e20 m-2 that we want. Beautiful startup. Next shot: Repeat with no changes. |
| Mar 9 2006 03:26:30:100PM | 1060309016 | Robert Granetz | Shot 16 -- Plasma. Good shot. nl_04=0.8e20 m-2. Density refuses to drop. Had a little ICRF from J-port. Next shot: Try for low elongation by reducing CLEARIN to -6.0 cm (from -2.0 cm). Also set nl_04 to 0.9e20 m-2. |
| Mar 9 2006 04:21:24:130PM | 1060309017 | Robert Granetz | Shot 17 -- Plasma. Good shot. Elongation=1.2 until around t=1.2 s, and then the EF2's get to zero, and the OH2's hit their rail. This causes some loss of control and the plasma touches the outboard limiter late in the flattop. Next shot: After t=1.1 s increase the elongation to try and prevent touching the outboard limiter. Also reduce nl_04 to 0.7e20 m-2. |
| Mar 9 2006 03:56:55:600PM | 1060309018 | Robert Granetz | Shot 18 -- Plasma. Good shot. nl_04=0.9e20 m-2. Kappa=1.2 until t=1.1 s, and then it re-elongates and stays under control. Perfect. Next shot: Set CLEARIN to -4 cm to shoot for an elongation of 1.4. I've extended the flattop of the elongation out to t=1.35 s, since it won't be pushing the power supplies as hard. Also adjust the density programming. |
| Mar 9 2006 04:02:26:410PM | 1060309019 | Robert Granetz | Shot 19 -- Fizzle. Got to 60 kA before it died. Didn't seem to hit anything. Next shot: subtract 0.1 mT from Br0 for palliative reasons. |
| Mar 9 2006 04:17:40:460PM | 1060309020 | Robert Granetz | Shot 20 -- Plasma. Good shot. nl_04=0.9e20 m-2. Elongation=1.34 until around t=1.3 s Next shot: Increase elongation to around 1.45 by setting CLEARIN to -3.0 cm. Tweak gas programming as well. |
| Mar 9 2006 04:27:20:647PM | 1060309021 | Robert Granetz | Shot 21 -- Fizzle. Next shot: subtract 0.2 mT from Br0. |
| Mar 9 2006 04:44:33:147PM | 1060309022 | Robert Granetz | Shot 22 -- Plasma. Good shot. nl_04=0.9e20 m-2. Kappa=1.45. Bad startup, lots of hard x-rays. Next shot: Set CLEARIN to -1 cm to try for the highest elongation of the day. Also add 1 ms to pre-fill. |
| Mar 9 2006 04:56:51:677PM | 1060309023 | Robert Granetz | Shot 23 -- Fizzle. I think the startup was killed by high carbon levels. I think the machine still needs some more cleanup. Next shot: On Joe's suggestion, subtract 0.2 mT from Br0. |
| Mar 9 2006 05:04:22:507PM | 1060309024 | Robert Granetz | Shot 24 -- Dud. (Startup changes were Joe's call) |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 08:58:58:070AM | Test | Ok | Gas Test Shot |
| 2 | 09:18:02:647AM | Test | Ok | TF Scanner Test Shot |
| 3 | 09:27:35:990AM | Plasma | Ok | |
| 4 | 11:25:13:037AM | Plasma | Ok | |
| 5 | 11:38:31:600AM | Plasma | Ok | |
| 6 | 12:14:10:770PM | Plasma | Ok | |
| 7 | 12:26:49:600PM | Plasma | Ok | |
| 8 | 12:40:18:007PM | Plasma | Ok | |
| 9 | 01:14:38:303PM | Plasma | Ok | |
| 10 | 01:40:44:333PM | Plasma | Ok | |
| 11 | 01:56:42:817PM | Plasma | Ok | |
| 12 | 02:09:32:710PM | Plasma | Ok | |
| 13 | 02:22:25:007PM | Plasma | Ok | |
| 14 | 02:46:48:833PM | Plasma | Ok | |
| 15 | 03:02:33:740PM | Plasma | Ok | |
| 16 | 03:15:19:803PM | Plasma | Ok | |
| 17 | 03:28:09:083PM | Plasma | Ok | |
| 18 | 03:41:29:757PM | Plasma | Ok | |
| 19 | 03:57:18:910PM | Plasma | Ok | |
| 20 | 04:10:08:397PM | Plasma | Ok | |
| 21 | 04:23:39:100PM | Plasma | Ok | |
| 22 | 04:36:14:897PM | Plasma | Ok | |
| 23 | 04:48:51:910PM | Plasma | Ok | |
| 24 | 05:01:34:460PM | Plasma | Ok | |