| Miniproposals | ||||||||||
|
| Operators | |
| Session leader(s): | Peter Oshea |
| Physics operator(s): | Joseph Snipes |
| Engineering operator(s): | Vinny Bertolino |
| Engineering Operator Run Comment |
| sameo |
| Session Leader Plans |
| Physics Operators Plans |
| Session Leader Summaries |
| Entered: Jul 7 2004 03:49:14:960PM |
| Author: To Be Determined |
| ***************************** * Run 960119 Modulated RF heating ( Mode Conversion at 6.4 T , H[He3] plasmas ) * Session Leader : O'Shea * Physics Operator : Snipes ***************************** Plan is to revisit the best heating parameters from 950608 (shot #17 ). and to do a current scan at that density ( nel_04 ~ 1.0 ) while achieving good RF modulation at a variety of frequencies. This is a retry of 951214. ************************************* Today was much more useful than 951214. Again (though for different reasons) it took a long time to converge on good central heating. This time around, there was just enough time to do a (very) quick current scan, even if the heating had not been optimized. Notable points: - Remember to close off open RF waveguide! - The cause(s) of very high Carbon levels should be investigated. (This just in!: Filter is partially off...measurements are not physical) - Central heating with Mode Conversion seems to occur at lower He3 fractions than expected. ************************************** Detailed run description: ----------------------------- Plasmas could not be achieved for the first 4 shots. It was observed that the carbon levels were up to an order of magnitude higher than they had been yesterday. Carbon had been on the increase through yesterday's run, but another difference is that we performed ECDC in H overnight. Charge exchange measurements indicate at Deuterium level of ~10% throughout the day. After shot 5, plasmas generally behaved very well, with only one early disruption (shot 9) and one mysterious alternator problem (shot 23). Though carbon levels remained high (0.07 on shot 27...very high, perhaps something's wrong with the filter???), very good target plasmas were established and maintained throughout the run. A preprogrammed pulse of fixed voltage level and varying width was used to determine the Helium level. An appropriate post-pulse plateau potential on the Helium valve was established which could maintain a constant signal on the McPherson HeII signal. Feedback was used on the Hydrogen valve alone to achieve the overall target density. Ion ratios will be determined from the change in electron density during the Helium pulse. Despite very happy target plasmas, we had a LOT of trouble coupling any power for the first half of the day. It wasn't until after shot 15 that the problem was discovered. The D-port transmitter had been taken apart last night and the uncovered waveguide was spewing 80 MHz into the power room and causing problems for E-port (and thankfully creating some pickup on magnet control voltages). Steady progress was made after this was corrected. Good central heating was not observed until the helium pulse was decreased from levels consistent with those which predict central location of the mode conversion layer. This apparent discrepancy will be studied, but for the run we just went with what seemed to work. In order to attempt a brief current scan, we could not optimize the plasma parameters for central heating. Got shots at 1.1 MA (25) and 600 kA (26, 27) in addition to the bulk of the run at 800 kA (best central heating on shots 22,& 24, off axis on shot 20). Fiducial in Deuterium (~30% from charge exchange) on last shot (28). See Physop report for detailed shot description. **************************************************** Shot summary (rough) Need a gas calibration shot. 001 Dud. No gas puff. 002 Fizzle. Carbon level is high, was going up yesterday...people seem pretty fairly concerned. 003 Ditto? Carbon is even higher. 004 Ditto Trying a Hydrogen fiducial at 5.3 T 005 Plasma! Density is a little weird....it's because the feedback gain goes to zero at 0.5....ooops. Trying for the whole thing again. 006 Plasma! Density trace is close to what we want. 007 Nice enough plasma, density looks promising (no info on H valve voltages) No RF to speak of. 008 Plasma, disrupts late (had added Argon late). Makes it through to the RF, which isn't coupled well, but does have levels of 0.5 MW and NO central heating. Maybe some heating out around channel 6 or 7, but not strong. 009 Disrupts at 0.4 sec, runaway density. No feedback from interferometer. Crate problems with the interferometer. Have to go into the cell to fix it In recool for (28 min @ 11:37)...43 minutes. fixed. 010 Plasma. Disrupts at 1 second. Did make it to the RF, density and Helium look great. Rf power really sucks...gets to 100kW max...tuning Mike and Jim tuned it up. 011 Nice plasma. No disruption. Zero RF, zero heating. Bob's your uncle. Try to retune again. 012 same old Going to higher magnetic field, for no apparent reason. 013 Rf better but still bad. One high power spike indicates some off axis heating. Going up to higher density 014 plasma, disrupts late. New density does what we wanted, RF still having troubles. Trying to move the plasma closer to the antenna. Hoping to improve coupling. 015 Same as 014 largely Noticing that there is some crosstalk between the the RF and EF1 demand signal....think about it and we fear that the coax from D-port was left open and could be broadcasting into the power room and maybe at the root of the problem..... Went in to see if it is foiled off....NO....did so (actually went in and through the waveguide switch) ...going to try again. Were probably spraying RF around pretty good. 016 Good plasma. Rf is better, got the tuning porch but the 1.5 MW only lasts for 50msec. Try again. 017 Good plasma... got lots of short high power spikes out of the RF but still needs work. Retry 018 Got about half the RF Moving to higher He fraction by slightly increasing Helium puff and lowering overall density target. 019 Heating looks worse....drat...theory sucks. 020 Got GREAT RF !!! nice modulation.... Heating is definitely off axis....moving to lower He.... 021 Ok rf, trippy, heating is better though ...density came down alright (inferred from the gas puffs) though both Heii and nel04 failed in daq 022 Brought the Helium puff down a little bit more, didn't retune the RF but we hit the tuning dead center and things are pretty good! Much better central heating! 023 Bringing the helium pulse down one more smidge before doing a scan. Some kind of kooky no-faults-failure.... The alternator just didn't do it's thing....flaky, retrying 024 Good ....22 was a little better so go back to the slightly wider pulse of 22 and start a current scan...ie try for a plasma at 1.1 MA 025 Good ! Plasma at 1.1MA. Got some heating too, very nice modulation ... take it and run for now. Go to lower current 026 Good plasma Ip = 600 kA , good enough RF... Heating is good but fades (changes) through shot... HeII didn't come up so i have to do these changes blind... Do a retry...only increase the helium pulse width slightly to keep the H puffing to reasonable levels and hopefully balance the gas ratios.... 027 Good plasma, good RF, gas puffing is more reasonable, but heating is largely the same..... 028 Fiducial in Deuterium. Good shot. |
| Physics Operator Summaries |
| Entered: Jul 7 2004 04:36:55:833PM |
| Author: To Be Determined |
| ICRF Modulation in Hydrogen (He3 minority) at 6.45 T 960119 Engineer in Charge: Vince Bertolino Physicist in Charge: Joseph Snipes Session Leader: Peter O'Shea Setup: Discharge clean in hydrogen. Enable A side with hydrogen at 20 psi and B side upper with He3 at 20 psi. Setup as on shot 960117002. The run will start at 0.8 MA, 6.45 T, and nl04 = 7 x 10^19 m^-2. Then, we will perform a current scan from 0.6 MA to 1 MA, varying the He3 concentration to get the best ICRF heating. The ICRF will be modulated to look at the heating. The density feedback failed on shot 9 and there were some problems with vertical disruptions on shots 8 and 10 that were apparently due to a problem with EF2L that was fixed after shot 10. Shot 23 failed mysteriously in that all power supplies running off of the alternator failed to fire with no apparent fault. Camac errors occurred on a number of shots with different diagnostics losing data at random. This intermittent problem with the CAMAC highway really needs to be fixed to get reliable data acquisition. Up until Wolfe commented to Golovato that there was RF pick-up on some of the power supplies, much of the RF power was being scattered in the power room rather than in the plasma because a cavity had been left open from last night. The cavity was closed for shot 16. After that, the RF improved considerably. In the end, we had a very good run despite the various problems. Electron heating was evident on a number of shots and we even managed to get in a quick current scan from 0.6 MA to 1.1 MA with good RF modulation. Scorecard: 28 shots, 23 plasmas, 3 fizzles, 1 dud, 1 mysterious fault. Shot 1 : Copied startup from shot 960117002 segment 1. Copied segment 2 from shot 951214004. Dud. B top gas valve not enabled. My mistake. Shot 2 : Extended pre-puff to 18 msec and enabled B top. Fizzle! Shot 3 : Changed Br offset from 7.5 to 6.5 mT, extended pre-puff to 19 msec. Fizzle! CII light at 0.022 mW/cm^2/ster, quite high! Shot 4 : Reduced pre-puff to 10 msec duration. Fizzle! High CII emission. Shot 5 : Copied startup and engineering setup from shot 960117001, which is a 5.3 T fiducial shot. But, we will run it in hydrogen. Density feedback shut off at 0.5 sec. Good shot. He3 puff from 0.6 sec to 0.7 sec at 90 V then set to 30 V until 1.0 sec. Shot 6 : Maintained density feedback to 1.5 sec. Raised TF to 6.5 T. Density programmed to 9 x 10^19 m^-2. Good shot. Shot 7 : Density programmed to 7 x 10^19 m^-2 until 0.7 sec, then raised to 1 x 10^20 m^-2 until 1.0 sec. He3 puff unchanged. Good shot. Shot 8 : Repeat. Disrupted at 0.95 sec. Seems to be a vertical problem. Large oscillation on EF2 from 0.84 sec. Shot 9 : Reduced He3 puff to 90 V from 0.6 to 0.68 sec and 30 V until 1 sec. Programmed the density to ramp from 0.62 to 0.7 sec. Disrupted at 0.4 sec. Lost density feedback from the beginning of the shot. Shot 10: Try again. Good shot. Disrupted at 1.02 sec. Large oscillation on EF2L from 0.9 sec. EF2 fault. Poor RF. Shot 11: Good shot. Worse RF. Shot 12: Ramped density request from 1 to 1.1 x 10^19 m^-2 from 0.7 to 1 sec. Good shot. Poor RF. Shot 13: Raising TF current to 195 kA or 6.9 T. Good shot. Poor RF. Shot 14: TF returned to 185 kA or 6.5 T. He3 puff started at 0.56 sec. Density programming changed to 8 x 10^19 m^-2 before 0.62 sec, then ramped to 1.2 at 0.7 sec, then ramped to 1.3 at 1 sec. Good shot. Poor RF. Shot 15: Moved RCUR out 3 mm to 0.67 m from 0.6 to 1.0 sec. Increased He3 puff from 0.68 sec to 1 sec to 40 V. Good shot. Poor RF. Shot 16: RF problem may have been due to an open cavity. Reached 1.5 MW for 50 msec. Good shot. RF still not well tuned. Shot 17: Put in Ian's RCUR offset switch at 1.1 sec to 2000 with a 7 mm inward jump programmed on RCUR at the same time to compensate. Good shot. RF a bit better. Rampdown about the same. Shot 18: Lowered ZXU and RCUR after 1.1 sec to try to improve the rampdown. Rampdown the same. RF above 1 MW for about 200 msec. Good shot. Shot 19: Reduced programmed density to 6 x 10^19 m^-2 before 0.62 sec, then ramped up to 1 x 10^20 m^-2 at 0.7 sec, then up to 1.1 x 10^20 m^-2 at 1 sec. He3 puff started at 0.54 sec. Kept ZXL low throughout the rampdown. Got 1.5 MW of RF with three modulations. Some heating visible on the ECE polychromator. Good shot. Shot 20: Kept RXL constant during the rampdown. Good shot. No change in the rampdown. Good RF modulation. Shot 21: Moved RXL in, ZXL up, CLEARIN in, and RCUR in during the rampdown. Good shot. RF tripped. Shot 22: Reduced He3 puff by another 10 msec from 0.54 to 0.6 sec. Good shot. Good RF modulation. Shot 23: Reduced He3 puff by another 10 msec from 0.54 to 0.59 sec. Failed mysteriously in that all power supplies running off of the alternator failed to fire with no apparent fault. Shot 24: Try again. Good shot. Good RF. Shot 25: Raising Ip to 1.1 MA. Increased He3 puff to 60 msec duration from 0.54 to 0.6 sec. Good shot. Good RF modulation. Disrupted at 1.18 sec around 0.75 MA. Shot 26: Lowering Ip to 0.6 MA. Good shot. Good RF modulation. Shot 27: Increased He3 puff by 10 msec from 0.54 to 0.6 sec. Good shot. Good RF modulation. Shot 28: Setup for a deuterium fiducial copying shot 960117001 and changing over B top (5 psi) and A side (K side) (20 psi) gas valves to deuterium. Return to 0.8 MA, 5.3 T. Argon disabled. Good fiducial. |
| Session Leader Comments |
| Physics Operator Comments | |||
| Jan 19 1996 08:56:32:910AM | 960119001 | Joseph Snipes | Shot 1: Copied startup from shot 960117002 segment 1. Copied segment 2 from
shot 951214004. Dud. B top gas valve not enabled. My mistake. |
| Jan 19 1996 09:11:45:330AM | 960119001 | Joseph Snipes | ICRF Modulation in Hydrogen (He3 minority) at 6.45 T 960119
Engineer in Charge: Vince Bertolino Physicist in Charge: Joseph Snipes Session Leader: Peter O'Shea Setup: Discharge clean in hydrogen. Enable A side with hydrogen at 20 psi and B side upper with He3 at 20 psi. Setup as on shot 960117002. The run will start at 0.8 MA, 6.45 T, and nl04 = 7 x 10^19 m^-2. Then, we will perform a current scan from 0.6 MA to 1 MA, varying the He3 concentration to get the best ICRF heating. The ICRF will be modulated to look at the heating. |
| Jan 19 1996 09:12:04:410AM | 960119001 | Joseph Snipes | Shot 1 : Copied startup from shot 960117002 segment 1. Copied segment 2
from shot 951214004. Dud. B top gas valve not enabled. My mistake. |
| Jan 19 1996 09:12:30:950AM | 960119002 | Joseph Snipes | Shot 2 : Extended pre-puff to 18 msec and enabled B top. Fizzle!
|
| Jan 19 1996 09:14:50:190AM | 960119003 | Joseph Snipes | Shot 3 : Changed Br offset from 7.5 to 6.5 mT, extended pre-puff to 19
msec. Fizzle! |
| Jan 19 1996 09:34:41:170AM | 960119004 | Joseph Snipes | Shot 4 : Reduced pre-puff to 10 msec duration. Fizzle!
|
| Jan 19 1996 10:05:41:190AM | 960119005 | Joseph Snipes | Shot 5 : Copied startup and engineering setup from shot 960117001, which is
a 5.3 T fiducial shot. But, we will run it in hydrogen. Density feedback shut off at 0.5 sec. |
| Jan 19 1996 10:15:09:860AM | 960119006 | Joseph Snipes | Shot 6 : Maintained density feedback to 1.5 sec. Raised TF to 6.5 T.
Density programmed to 9 x 10^19 m^-2. Good shot. |
| Jan 19 1996 10:49:55:340AM | 960119007 | Joseph Snipes | Shot 7 : Density programmed to 7 x 10^19 m^-2 until 0.7 sec, then raised to
1 x 10^20 m^-2 until 1.0 sec. He3 puff unchanged. Good shot. |
| Jan 19 1996 11:15:54:060AM | 960119008 | Joseph Snipes | Shot 8 : Repeat. Disrupted at 0.95 sec. Seems to be a vertical problem.
Large oscillation on EF2 from 0.84 sec. |
| Jan 19 1996 11:16:17:450AM | 960119009 | Joseph Snipes | Shot 9 : Reduced He3 puff to 90 V from 0.6 to 0.68 sec and 30 V until 1
sec. Programmed the density to ramp from 0.62 to 0.7 sec. Disrupted at 0.4 sec. Lost density feedback from the beginning of the shot. |
| Jan 19 1996 12:13:18:600PM | 960119010 | Joseph Snipes | Shot 10: Try again. Good shot. Disrupted at 1.02 sec. Large oscillation on
EF2L from 0.9 sec. EF2 fault. Poor RF. |
| Jan 19 1996 12:29:19:440PM | 960119011 | Joseph Snipes | Shot 11: Good shot. Worse RF.
|
| Jan 19 1996 01:11:39:420PM | 960119012 | Joseph Snipes | Shot 12: Ramped density request from 1 to 1.1 x 10^19 m^-2 from 0.7 to 1
sec. Good shot. Poor RF. |
| Jan 19 1996 01:12:37:740PM | 960119013 | Joseph Snipes | Shot 13: Raising TF current to 195 kA or 6.9 T. Good shot. Poor RF.
|
| Jan 19 1996 01:13:04:490PM | 960119014 | Joseph Snipes | Shot 14: TF returned to 185 kA or 6.5 T. He3 puff started at 0.56 sec.
Density programming changed to 8 x 10^19 m^-2 before 0.62 sec, then ramped to 1.2 at 0.7 sec, then ramped to 1.3 at 1 sec. Good shot. Poor RF. |
| Jan 19 1996 01:42:51:390PM | 960119015 | Joseph Snipes | Shot 15: Moved RCUR out 3 mm to 0.67 m from 0.6 to 1.0 sec. Increased
He3 puff from 0.68 sec to 1 sec to 40 V. Good shot. Poor RF. |
| Jan 19 1996 02:00:11:100PM | 960119016 | Joseph Snipes | Shot 16: RF problem may have been due to an open cavity. Reached 1.5 MW
for 50 msec. Good shot. RF still not well tuned. |
| Jan 19 1996 02:13:22:430PM | 960119017 | Joseph Snipes | Shot 17: Put in Ian's RCUR offset switch at 1.1 sec to 2000 with a 7 mm
inward jump programmed on RCUR at the same time to compensate. Good shot. RF a bit better. Rampdown about the same. |
| Jan 19 1996 02:26:47:920PM | 960119018 | Joseph Snipes | Shot 18: Lowered ZXU and RCUR after 1.1 sec to try to improve the rampdown.
Rampdown the same. RF above 1 MW for about 200 msec. Good shot. |
| Jan 19 1996 02:41:17:980PM | 960119019 | Joseph Snipes | Shot 19: Reduced programmed density to 6 x 10^19 m^-2 before 0.62 sec, then
ramped up to 1 x 10^20 m^-2 at 0.7 sec, then up to 1.1 x 10^20 m^-2 at 1 sec. He3 puff started at 0.54 sec. Kept ZXL low throughout the rampdown. Got 1.5 MW of RF with three modulations. Some heating visible on the ECE polychromator. Good shot. |
| Jan 19 1996 03:05:31:500PM | 960119020 | Joseph Snipes | Shot 20: Kept RXL constant during the rampdown. Good shot. No change in
the rampdown. Good RF modulation. |
| Jan 19 1996 03:38:43:160PM | 960119021 | Joseph Snipes | Shot 21: Moved RXL in, ZXL up, CLEARIN in, and RCUR in during the rampdown.
Good shot. RF tripped. |
| Jan 19 1996 03:39:03:480PM | 960119022 | Joseph Snipes | Shot 22: Reduced He3 puff by another 10 msec from 0.54 to 0.6 sec. Good
shot. Good RF modulation. |
| Jan 19 1996 03:52:08:180PM | 960119023 | Joseph Snipes | Shot 23: Reduced He3 puff by another 10 msec from 0.54 to 0.59 sec.
Failed mysteriously in that all power supplies running off of the alternator failed to fire with no apparent fault. |
| Jan 19 1996 04:15:02:750PM | 960119024 | Joseph Snipes | Shot 24: Try again. Good shot. Good RF.
|
| Jan 19 1996 04:15:19:530PM | 960119025 | Joseph Snipes | Shot 25: Raising Ip to 1.1 MA. Increased He3 puff to 60 msec duration from
0.54 to 0.6 sec. Good shot. Good RF modulation. Disrupted at 1.18 sec around 0.75 MA. |
| Jan 19 1996 04:42:17:670PM | 960119026 | Joseph Snipes | Shot 26: Lowering Ip to 0.6 MA. Good shot. Good RF modulation.
|
| Jan 19 1996 05:05:01:630PM | 960119027 | Joseph Snipes | Shot 27: Increased He3 puff by 10 msec from 0.54 to 0.6 sec. Good shot.
Good RF modulation. |
| Jan 19 1996 05:14:03:390PM | 960119028 | Joseph Snipes | Shot 28: Setup for a deuterium fiducial copying shot 960117001 and changing
over B top (5 psi) and A side (K side) (20 psi) gas valves to deuterium. Return to 0.8 MA, 5.3 T. Argon disabled. Good fiducial. |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 08:42:47:300AM | Plasma | Ok | |
| 2 | 09:00:32:690AM | Plasma | Ok | |
| 3 | 09:11:58:140AM | Plasma | Ok | |
| 4 | 09:25:32:840AM | Plasma | Ok | no faults |
| 5 | 09:50:55:090AM | Plasma | Ok | |
| 6 | 10:04:50:820AM | Plasma | Ok | |
| 7 | 10:20:48:920AM | Plasma | Ok | |
| 8 | 10:47:10:440AM | Plasma | Ok | |
| 9 | 11:07:42:660AM | Plasma | Ok | |
| 10 | 11:52:15:340AM | Plasma | Ok | |
| 11 | 12:10:41:950PM | Plasma | Ok | |
| 12 | 12:29:57:670PM | Plasma | Ok | |
| 13 | 12:45:40:420PM | Plasma | Ok | |
| 14 | 01:04:38:350PM | Plasma | Ok | |
| 15 | 01:26:30:680PM | Plasma | Ok | |
| 16 | 01:43:11:380PM | Plasma | Ok | |
| 17 | 01:58:56:060PM | Plasma | Ok | |
| 18 | 02:16:04:520PM | Plasma | Ok | |
| 19 | 02:33:55:070PM | Plasma | Ok | |
| 20 | 02:49:30:330PM | Plasma | Ok | |
| 21 | 03:10:41:190PM | Plasma | Ok | |
| 22 | 03:26:18:180PM | Plasma | Ok | |
| 23 | 03:43:28:010PM | Plasma | Ok | |
| 24 | 03:51:33:000PM | Plasma | Ok | |
| 25 | 04:06:19:890PM | Plasma | Ok | |
| 26 | 04:28:53:850PM | Plasma | Ok | |
| 27 | 04:43:17:290PM | Plasma | Ok | |
| 28 | 05:06:25:800PM | Plasma | Ok | |