| Miniproposals | ||||||||||||
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| Operators | |
| Session leader(s): | Jim Irby,Steve Scott |
| Physics operator(s): | Robert Granetz |
| Engineering operator(s): | Unknown |
| Engineering Operator Run Comment |
| MP 354 Study of tail confinement deuterium DNB; MP 348 boron salt shaker |
| Session Leader Plans |
| Physics Operators Plans |
| Session Leader Summaries |
| Entered: Jul 7 2004 03:49:34:023PM |
| Author: Steve Scott |
| Session Leader Summary for MP354 Tuesday, July 15, 2003 S. D. Scott Objective: identify possible anomalous losses of energetic ions by comparing measured to expected neutron emission during injection of 50 ms deuterium diagnostic neutral beam (DNB). This was an excellent run that accomplished more than we originally planned to study. Pleasant surprises and findings: 1. The DNB operated smoothly in deuterium, in fact it obtained a more constant extracted current than we have previously obtained in hydrogen. 2. Changeover from H to D took only a few shots. 3. The full-energy fraction was reasonable (initial indications from Bill Rowan were circa 25% full energy fraction by density ... final numbers TBD). 4. Neutron emission by DNB was comparable to or greater than the thermonuclear plasma except during RF+H-mode. Other major findings: 1. Overall neutron emission from the DNB was substantially less than heuristic calculations. Measured values were typically in the range 1-3 x 10^12/s except at the lowest plasma currents. We had expected 1.3e13 * Te(keV)^1.5, i.e. we generally expected values in the mid-10^13 range. We aren't sure whether this suggests anomalous fast-ion losses or an inadequacy of the heuristic calculationss, but we lean to the latter. 2. Decay time of neutron emission was in the range 2-4 ms following beam turn off. 3. Significantly, we observed little or no difference in the neutron emission between shots with and without locked modes. This indicates that locked modes probably do not cause additional fast-ion losses in these plasmas. We were able to examine the following parameters on possible anomalous fast ion losses: 1. Density (which affects slowing-down time directly, and deposition profile): Nel = 0.5 - 2.0 e20. 2. RF heating: zero to about 2 MW. 3. IP: mostly at 1.0 MA, but also some data at 0.6, 0.4, and even 0.25 MA. 4. BT: mostly 5.4 Tesla, but also a couple of shots at 4.1 Tesla. 5. Regimes: mostly L-mode, but also a few shots with various flavors of H-mode including dithering. Note: since this experiment was piggy-backed on Jim Irby's boron salt-shaker expt, for which the Thomson and other shutters were closed, we do not have full transport documentation on all shots. Congratulations to Dexter Beals, Bill Rowan, Bob Granetz et al for a highly successful run -- |
| Entered: Jul 7 2004 03:49:34:227PM |
| Author: Steve Scott |
| Run Summary for Piggyback Boron Injection Experiment Mini-Proposal 348a, Initial Tests of the Boron Injector SL: Irby The boron injector was installed on e-top on Monday, pumped down overnight, and opened to C-Mod vacuum on Tuesday morning just before the run. Initial tests indicated that we were getting much less boron than expected, but we did not have time to make any changes before the run. So boron deposition was on the order of 5 or 10 times less than we had hoped for (expected approx 0.15 mg/pulse, or 1000, 50 um diameter, dust particles). We are in the process of quantifying the actual amount/pulse of boron deposited and determining what caused the problem with the injector. Diagnostics for the injector include a 90 degree laser scattering signal from the boron dust that tells us if boron is actually being deposited, and a photo-diode viewing the plasma from e-top through a rather wideband BIII filter (4498A+-200A). The boron takes about 150 ms to drop into the scattering region and another 450 ms to drop into the plasma (assuming only g matters). We had expected to see an increase in the plasma light as the boron entered the plasma as well as changes in the 2 PI diode, among other diagnostics. However, with the small amount of boron actually deposited, we should not expect easily detectible signals (total radiated power levels in the 2500 W range). So we were not able to state with any certainty that the boron made it into the plasma. However, looking down the port through the PCI window does not show any obvious deposits of boron on the teardrop adapter, or elsewhere. So the most reasonable assumption I think is that the boron did make into the plasma but at too low a level to detect. This problem will be very easy to fix for the October run campaign. |
| Physics Operator Summaries |
| Entered: Jul 7 2004 04:37:18:800PM |
| Author: Robert Granetz |
| Physics operator summary for run 1030715 (Tuesday): Purpose: MP 354 - Study of tail confinement using deuterium DNB MP 348 - Test of boron "salt shaker" hardware Session leader: S.Scott/R. Granetz, J. Irby Physics operator: R. Granetz Engineers in charge: Summary: Scorecard: 27 plasmas 5 fizzles 1 duds 0 test or no-power shot cycle 0 aborted and/or screwed up by computer problems ---------- 33 total ------------------------------------------------------------------------------- Engineering setup for Tuesday, 15 July 2003 Purpose: MP 354 - Study of tail confinement using deuterium DNB MP 348 - Test of boron "salt shaker" hardware Session leader: S.Scott/R. Granetz, J. Irby Physics operator: R. Granetz ECDC overnight in D2 at 2e-4 Torr, stopping by 07:00. Bake at 60 C overnight as well. Run begins at 09:00 and ends at 17:00. Power systems the same as on 1030507012 (1.0 MA, 5.4 T, lower single null) A-coils should be hooked up as on 1030507012 (-Dtop +Dbot +Jtop -Jbot), but the power supply should NOT be enabled. ** NOTE **: Since "boronization" will be occurring throughout today's run, all shutters should be closed, at least until we know if there's significant coating of windows. If RF has fired into the vacuum chamber prior to the start of the run, then we will need to do 10 minutes of ECDC before the first shot. Gas setup: fill B-Top with 6 psi D2 Hybrid enabled (PG4) fill B-side lower with 1 psi Ar Hybrid enabled (PG1) fill B-side upper with 10 psi D2 Hybrid DISABLED (PG2) (for ECDC) fill C-side with 30 psi D2 Hybrid enabled (PG3) Enable the following gate valves, assuming no vacuum problems: ECE, DNB ------------------------------------------------------------------------------- RF Setup: All 4 transmitters in Run On by 08:00. We will want P >= 3 MW in the AFTERNOON. ------------------------------------------------------------------------------- Run Plan: Start from 1030507012 (no RF), except lower the density to nl_04=1.0e20 m-2. This shot should not have a locked mode. Fire deuterium DNB and record neutron rate and beam component spectra. Boron "salt shaker" will operate late in each shot, after the DNB pulse. Next, turn on A-coils at maximum level, which should generate a locked mode. Fire deuterium DNB and record neutron rate and beam component spectra. 2nd experiment: same starting conditions, but lower the Btor to change field error ratio. Record neutron rate. Possibly repeat with A-coils on. 3rd experiment: same starting conditions, but turn on high-power RF, with a sharp 1-2 MW notch so that break-in-slope analysis can be done for energy confinement. Fire deuterium DNB during RF and record neutron rate. Finally, if there is time, we may try to squeeze in two shots to complete Ian's database of locked mode parameters. ------------------------------------------------------------------------------- ECDC was done overnight, as well as a 60 C bake. Hybrid coldstart done by the engineering group; no errors found Loaded PCS segment 2 from shot 1030507012 (1.0 MA, 5.4 T, single null lower), segment 1 from last shot from last Friday. Confirmed that nl_04 to 1.0e20 m-2 in segment 2. Set deuterium DNB to fire at t=1.0 s. ------------------------------------------------------------------------------- Shot 01 -- Plasma. Good shot. DNB faulted immediately, so null result on neutrons. Jim reports boron shaker worked. RGA sees boron after the shot. ECE sawteeth were very small, but Amanda confirms that there was no locked mode. Next shot: repeat to get good DNB pulse. Also disable argon valve (at Yujin's request). Shot 02 -- Fizzle. Good beam pulse though. Next shot: reduce pre-fill puff by 4 ms. Shot 03 -- Fizzle. Good beam pulse. Next shot: reduce pre-fill some more. Shot 04 -- Plasma. Good shot. No locked mode. Good DNB pulse. Got a very clear neutron signal!! Rdd=1.5e12 n/s. Got a beam spectrum too. Rdd decay time is only a few ms (Steve reports 3-4 ms.) Next shot: repeat, no changes Shot 05 -- Dud. No TF. Next shot: try again, no changes Shot 06 -- Fizzle. Good DNB pulse. Next shot: reduce pre-fill a couple more ms Shot 07 -- Plasma. Disrupted very early, at t=0.41 s, which is long before the DNB pulse at 1.0 s. Good DNB pulse. Two big injections killed this shot, maybe due to large MHD activity. Next shot: Set crowbar close times to t=0.07 s (from t=0.12 s) on the three OH supplies. Shot 08 -- Plasma. Good shot. But DNB faulted after 7 ms. No locked mode. Neutrons just barely asymptote at 1.5e12 n/s. Got TS profiles, since Jim agreed to hold off on the boron for this shot. H/D ratio is about 7%. Next shot: turn on A-coils at full current. Shot 09 -- Plasma. Good shot. DNB faulted after 18 ms. Locked mode started at about 0.9 s. Neutron rate was slightly higher! Rdd=1.9e12 n/s. Next shot: repeat, no changes. Turn boron shaker back on, so close the TS shutter. Shot 10 -- Plasma. Good shot. DNB pulse was almost full length. Locked mode starts right about the time of the beam pulse. again. Neutron rate = 1.5-1.7e12 n/s. Next shot: increase A-coil current and start it earlier. Dexter has raised the anode gas pressure slightly. Shot 11 -- Plasma. Good shot. Solidly locked at t=1.0 s when the beam fires. No boron shaking on this shot. Z_bolo was enabled, as was the Thomson. Rdd=1.9e12 n/s. Amanda reports that central Te and ne still changing significantly around t=1.0 s. Next shot: start A-coil flattop earlier. Delay DNB until t=1.1 s. Boron shaker will be on, therefore Z-Bolo and Thomson will be off. Shot 12 -- Plasma. Good shot. Locked mode did not start until after the DNB fired. So this is essentially a repeat of shot 004. Rdd=1.5-1.6 n/s. Next shot: repeat one last time with these settings. Shot 13 -- Plasma. Good shot. Had a locked mode at the DNB time. Density is still changing a tiny amount. Rdd=1.6e12 n/s. Next shot: turn on RF (with a notch programmed in). Disable the A-coils. Boron will be shaking. Shot 14 -- Plasma. Good shot. Prf=2 MW, with notch at t=0.95-1.00. Good DNB pulse at t=1.10-1.15. RF gives Rdd of 2e12 n/s, and DNB adds about the same amount. No locked mode, as expected. H-mode starts at t=1.24 s, well after the time we're interested in. Next shot: Try for more RF power. No boron shaker, so Thompson and Z-bolo will be on. Shot 15 -- Plasma. Good shot. Long EDA H-mode during the DNB pulse, so nl_04 is at 2.0e20 m-2. We think we can still see a DNB increase of roughly 1e12 n/s, but it's really dominated by the RF and by sawteeth (max rate is 1.0e13 n/s. H/D = 8%. Zeff=1.1 . Next shot: turn off RF, decrease nl_04 to 0.5e20 m-2, reverse A-coil polarity and turn back on. Shot 16 -- Plasma. Good shot. Ohmic. Good DNB pulse. nl_04=0.7e20 m-2. No locked mode. Rdd=2.8e12 m/s. Jim reports no problems with boron coatins on windows. Next shot: try to reduce density some more. Turn on Thomson and Z-bolo for the rest of the run. Shot 17 -- Plasma. Good shot. Good DNB pulse. nl_04=0.5e20 m-2. Rdd=3.2e12 n/s. No locked mode. Zeff=1.5. Startup nearly didn't make it. Next shot: turn off A-coils. Also add 3 ms to pre-fill puff. Shot 18 -- Plasma. Good shot. Good beam pulse. Max Rdd=2.4e12 n/s, but there was a large injection at 1 s, which affected a lot of the signals. Locked mode began just before t=1 s. Next shot: repeat, hoping not to get an impurity injection. Shot 19 -- Fizzle. Next shot: reduce pre-fill puff by 1 ms. Shot 20 -- Plasma. Good shot. But DNB didn't fire. Locked mode begins at t=1.02 s. Good startup Next shot: try again. No changes Shot 21 -- Plasma. Disrupted early, at t=0.38 s. DNB didn't fire again. Dexter figured out that the gate valve permissive was turned off, which explains the previous shot as well. Next shot: one more try. Shot 22 -- Plasma. Disrupted at t=0.85 s, just as a locked mode started. Looks like another impurity injection. Next shot: another 'one more try', no changes. Shot 23 -- Plasma. Good shot. Good beam pulse. nl_04=0.5e20 m-2. Locked mode starts at t=1.0 s. Rdd=2.5e12 n/s. Next shot: try to do Ian's two shots. Start with nl_04=0.8e20 m-2 and turn off the density and pre-programmed gas at t=0.6 seconds, which should result in a density rampdown. No A-coils for this coming shot. Shot 24 -- Plasma. Hard disruption at 1.52 s. Locked mode at t=1.1 s, just when the beam fires. Rdd=2.8e12 n/s. I think this was a midplane disruption. Density did not ramp down exactly as wanted. Next shot: similar, but start the densty rampdown at nl_04=0.6e20 m-2, try try and get lower. Still no A-coils. Shot 25 -- Plasma. Hard disruption at t=1.17 s. Density ramped down very low, as desired. Locked mode begins at t=0.84 s. Good DNB pulse. Rdd=2.3e12 n/s. Next shot: repeat, but with A-coils turned on for nearly the entire shot. Shot 26 -- Fizzle. Disruption recovery? Next shot: take 1 ms off of the pre-fill puff Shot 27 -- Plasma. Disrupted at t=1.41 s. But we succeeded in preventing a locked mode, so whatever caused the disruption, it wasn't due to a locked mode. End of Ian's shots. Next shot: start a Btor rampdown investigation to see if higher ratio of Error field to Btor makes a difference to DNB neutron production. Re-load segment 2 from shot 004, reduce nl_04 to 0.8e20 m-2, ramp Btor down to 4 T early in shot and then hold there. Turn off A-coils. Shot 28 -- Plasma. Disrupted at t=0.88 s. Btor flattens at 4.1 T. q95=3.0 There's a locked mode after t=0.7 s. Next shot: turn on the A-coils, with waveform programmed for the entire shot. If this doesn't improve things, I'll have to increase Btor a little to avoid q95=3 Shot 29 -- Plasma. Good shot. No locked mode. Good DNB pulse. q95=3.0. nl_04=0.85e20 m-2. Got an ohmic H-mode late in the shot. Next shot: repeat, except reduce the density to nl_04=0.6e20 m-2. Shot 30 -- Plasma. Good shot. No locked modes, but multiple ELMfree H-modes, including during the DNB pulse. Rdd increase is about 1.2e12 n/s, since the density is high due to the H-mode. Next shot: let's explore a different plasma current. Go to 0.6 MA, Btor=5.4 T, nl_04=0.6e20 m-2. A-coils off. Shot 31 -- Plasma. Good shot. No locked mode. I forgot to tell Amanda to change the grating back. Ip=0.6 MA, Btor=5.4 T, nl_04=0.67e20 m-2. Good beam pulse. Rdd=1.8e12 n/s. This is somewhat lower than shot 16 at 1 MA. Next shot: repeat, this time with central GPC. Shot 32 -- Plasma. Good shot. No locked mode. Perhaps some little H-modes, but not during the DNB pulse. Ip=0.4 MA. Rdd=1.0e12 n/s. Next shot: reduce plasma current to 250 kA. Shot 33 -- Plasma. Good shot. Some kind of dithering or marfing throughout most of the shot. Good DNB pulse. Ip=250 kA, Btor=5.4 T, nl_04=0.7e20 m-2. Rdd=0.7e12 n/s. End of run. |
| Session Leader Comments | |||
| Jul 15 2003 08:22:07:427AM | Jim Irby | The boron injector was installed on e-top yesterday and pumped down overnight. When we opened it to the vessel this morning the pressure went from 1.5 to 3 e-7 Torr and them pumped right back down. No sign of water on the RGA, just a little mass 28 for a couple of minutes. The injector did not work initially. Jim Rosati hit the top of the solenoid and got it working again. We think the piston was jammed in the up position. There is some question about the size of the new powder since it was not sieved after the bake. | |
| Jul 15 2003 09:15:53:623AM | 1030715001 | Jim Irby | Boron gate [0.75,10.,.5,2] --- should result in first plasma interaction at 1.3 s or so... Yijun will be monitoring the moly. Got some boron ---- BIII signal saturates about when I expected the boron Plasma light seen on scattering signal even with laser line filter in place. |
| Jul 15 2003 09:44:24:100AM | 1030715002 | Jim Irby | fizzle some boron injected that's now in the divertor |
| Jul 15 2003 09:44:54:617AM | 1030715003 | Jim Irby | fizzle boron injected again |
| Jul 15 2003 09:53:22:917AM | 1030715004 | Jim Irby | plasma boron injection turned off for this shot BIII signal saturated --- will need cell access to change gain |
| Jul 15 2003 10:01:06:627AM | 1030715005 | Jim Irby | boron gate [0.75,20.,.5,5] No TF --- more boron into divertor |
| Jul 15 2003 10:35:22:420AM | 1030715006 | Jim Irby | Fizzle more boron in divertor |
| Jul 15 2003 10:37:18:810AM | 1030715007 | Jim Irby | boron injection off |
| Jul 15 2003 10:54:47:477AM | 1030715008 | Jim Irby | boron injection off until we get a couple of plasmas Bill Parkin and I dropped gain in BIII amp by factor of 2 (1 MOhm ---> 500 kOhm) Plasma --- signal level on BIII did drop as expected |
| Jul 15 2003 11:09:07:000AM | 1030715009 | Jim Irby | No boron injection plasma |
| Jul 15 2003 11:29:25:700AM | 1030715010 | Jim Irby | boron gate [.75,10,.5,4] plasma ---- boron seen on scattering signal BIII light rises starting at 1.1 s, but does not seem to be the result of the injection? |
| Jul 15 2003 11:41:24:267AM | 1030715011 | Jim Irby | No boron injection plasma --- don't think boron injection had anything to do with the fizzles |
| Jul 15 2003 11:58:07:747AM | 1030715012 | Jim Irby | boron gate [.75, 20, .5, 10.] plasma --- boron injections, but still nothing definitive on other diagnostics |
| Jul 15 2003 12:11:24:610PM | 1030715013 | Jim Irby | boron gate [.75, 20, .5, 15] plasma --- boron was injected, but no sign of it in plasma |
| Jul 15 2003 12:23:02:597PM | 1030715014 | Jim Irby | boron gate [.75, 25, .5, 20] plasma --- not as much boron injected at 25 Hz |
| Jul 15 2003 12:36:21:790PM | 1030715015 | Jim Irby | no boron injection plasma -- h-mode |
| Jul 15 2003 01:03:59:567PM | 1030715016 | Jim Irby | boron gate [0.75, 10, .5, 10] plasma --- got some boron, but getting less each shot |
| Jul 15 2003 01:17:48:493PM | 1030715017 | Jim Irby | boron gate [.75, 10, .5, 10] plasma --- still low deposition rate |
| Jul 15 2003 01:31:13:060PM | 1030715018 | Jim Irby | boron gate [ .65, 10, .5, 20] plasma --- |
| Jul 15 2003 01:42:24:563PM | 1030715019 | Jim Irby | boron gate [ .65, 10, .5, 10] fizzle --- boron went in at low level |
| Jul 15 2003 01:53:05:360PM | 1030715020 | Jim Irby | boron gate [0.65, 10, .5, 10] plasma |
| Jul 15 2003 02:03:15:517PM | 1030715021 | Jim Irby | boron gate [ 0.65, 10, .5, 5] early disruption --- boron after end of plasma |
| Jul 15 2003 02:30:43:933PM | 1030715022 | Jim Irby | boron gate [0.5, 40., 0.5, 40] plasma, but disrupted at .8 s ---- 40 Hz rate gives still less boron |
| Jul 15 2003 02:35:38:567PM | 1030715023 | Jim Irby | boron gate [0.65, 10,.5,5] plasma --- |
| Jul 15 2003 02:49:10:133PM | 1030715024 | Jim Irby | no boron injection plasma |
| Jul 15 2003 03:06:39:130PM | 1030715025 | Jim Irby | boron gate [.65,20,.5,20] plasma to 1.16 s --- |
| Jul 15 2003 03:16:36:440PM | 1030715026 | Jim Irby | boron gate [0.65,10,.5,10] |
| Jul 15 2003 04:05:18:690PM | 1030715027 | Jim Irby | boron gate [0.65,10,.5,10] plasma to 1.42 s ---- |
| Jul 15 2003 04:06:05:283PM | 1030715029 | Jim Irby | gate [0.65,30,.5,30] plasma --- very little boron injection --- need a hammer |
| Jul 15 2003 04:22:19:963PM | 1030715030 | Jim Irby | boron gate [0.65,10.,.5,10.] |
| Jul 15 2003 04:40:41:727PM | 1030715030 | Jim Irby | boron gate [.65,10,.5,10] |
| Jul 15 2003 04:38:37:020PM | 1030715031 | Jim Irby | boron gate [.65,10,.5,30] |
| Jul 15 2003 04:49:54:787PM | 1030715032 | Jim Irby | boron gate [.65,10,.5,30] Jim Rosati has taken a well calibrated hammer to the boron injector plasma --- very little change to boron level |
| Jul 15 2003 05:53:30:040PM | 1030715033 | Jim Irby | boron gate [.65,10,.5,3] |
| Physics Operator Comments | |||
| Jul 15 2003 08:28:18:273AM | Robert Granetz | Engineering setup for Tuesday, 15 July 2003 Purpose: MP 354 - Study of tail confinement using deuterium DNB MP 348 - Test of boron "salt shaker" hardware Session leader: S.Scott/R. Granetz, J. Irby Physics operator: R. Granetz ECDC overnight in D2 at 2e-4 Torr, stopping by 07:00. Bake at 60 C overnight as well. Run begins at 09:00 and ends at 17:00. Power systems the same as on 1030507012 (1.0 MA, 5.4 T, lower single null) A-coils should be hooked up as on 1030507012 (-Dtop +Dbot +Jtop -Jbot), but the power supply should NOT be enabled. ** NOTE **: Since "boronization" will be occurring throughout today's run, all shutters should be closed, at least until we know if there's significant coating of windows. If RF has fired into the vacuum chamber prior to the start of the run, then we will need to do 10 minutes of ECDC before the first shot. Gas setup: fill B-Top with 6 psi D2 Hybrid enabled (PG4) fill B-side lower with 1 psi Ar Hybrid enabled (PG1) fill B-side upper with 10 psi D2 Hybrid DISABLED (PG2) (for ECDC) fill C-side with 30 psi D2 Hybrid enabled (PG3) Enable the following gate valves, assuming no vacuum problems: ECE, DNB ------------------------------------------------------------------------------- RF Setup: All 4 transmitters in Run On by 08:00. We will want P >= 3 MW in the AFTERNOON. ------------------------------------------------------------------------------- Run Plan: Start from 1030507012 (no RF), except lower the density to nl_04=1.0e20 m-2. This shot should not have a locked mode. Fire deuterium DNB and record neutron rate and beam component spectra.. Boron "salt shaker" will operate late in each shot, after the DNB pulse. Next, turn on A-coils at maximum level, which should generate a locked mode. Fire deuterium DNB and record neutron rate and beam component spectra. 2nd experiment: same starting conditions, but lower the Btor to change field error ratio. Record neutron rate. Possibly repeat with A-coils on. 3rd experiment: same starting conditions, but turn on high-power RF, with a sharp 1-2 MW notch so that break-in-slope analysis can be done for energy confinement. Fire deuterium DNB during RF and record neutron rate. Finally, if there is time, we may try to squeeze in two shots to complete Ian's database of locked mode parameters. | |
| Jul 15 2003 08:29:23:980AM | Robert Granetz | ECDC was done overnight, as well as a 60 C bake. Hybrid coldstart done by the engineering group; no errors found Loaded PCS segment 2 from shot 1030507012 (1.0 MA, 5.4 T, single null lower), segment 1 from last shot from last Friday. Confirmed that nl_04 to 1.0e20 m-2 in segment 2. Set deuterium DNB to fire at t=1.0 s. | |
| Jul 15 2003 09:12:25:793AM | 1030715001 | Robert Granetz | Shot 01 -- Plasma. Good shot. DNB faulted immediately, so null result on neutrons. Jim reports boron shaker worked. RGA sees boron after the shot. ECE sawteeth were very small, but Amanda confirms that there was no locked mode. Next shot: repeat to get good DNB pulse. Also disable argon valve (at Yujin's request). |
| Jul 15 2003 09:22:14:487AM | 1030715002 | Robert Granetz | Shot 02 -- Fizzle. Good beam pulse though. Next shot: reduce pre-fill puff by 4 ms. |
| Jul 15 2003 09:37:29:563AM | 1030715003 | Robert Granetz | Shot 03 -- Fizzle. Good beam pulse. Next shot: reduce pre-fill some more. |
| Jul 15 2003 09:57:14:390AM | 1030715004 | Robert Granetz | Shot 04 -- Plasma. Good shot. No locked mode. Good DNB pulse. Got a very clear neutron signal!! Rdd=1.5e12 n/s. Got a beam spectrum too. Rdd decay time is only a few ms (Steve reports 3-4 ms.) Next shot: repeat, no changes |
| Jul 15 2003 10:00:29:563AM | 1030715005 | Robert Granetz | Shot 05 -- Dud. No TF. Next shot: try again, no changes |
| Jul 15 2003 10:17:01:720AM | 1030715006 | Robert Granetz | Shot 06 -- Fizzle. Good DNB pulse. Next shot: reduce pre-fill a couple more ms |
| Jul 15 2003 10:35:10:937AM | 1030715007 | Robert Granetz | Shot 07 -- Plasma. Disrupted very early, at t=0.41 s, which is long before the DNB pulse at 1.0 s. Good DNB pulse. Two big injections killed this shot, maybe due to large MHD activity. Next shot: Set crowbar close times to t=0.07 s (from t=0.12 s) on the three OH supplies. |
| Jul 15 2003 10:58:08:373AM | 1030715008 | Robert Granetz | Shot 08 -- Plasma. Good shot. But DNB faulted after 7 ms. No locked mode. Neutrons just barely asymptote at 1.5e12 n/s. Got TS profiles, since Jim agreed to hold off on the boron for this shot. H/D ratio is about 7%. Next shot: turn on A-coils at full current. |
| Jul 15 2003 11:10:30:047AM | 1030715009 | Robert Granetz | Shot 09 -- Plasma. Good shot. DNB faulted after 18 ms. Locked mode started at about 0.9 s. Neutron rate was slightly higher! Rdd=1.9e12 n/s. Next shot: repeat, no changes. Turn boron shaker back on, so close the TS shutter. |
| Jul 15 2003 11:26:57:167AM | 1030715010 | Robert Granetz | Shot 10 -- Plasma. Good shot. DNB pulse was almost full length. Locked mode starts right about the time of the beam pulse. again. Neutron rate = 1.5-1.7e12 n/s. Next shot: increase A-coil current and start it earlier. Dexter has raised the anode gas pressure slightly. |
| Jul 15 2003 11:47:33:747AM | 1030715011 | Robert Granetz | Shot 11 -- Plasma. Good shot. Solidly locked at t=1.0 s when the beam fires. No boron shaking on this shot. Z_bolo was enabled, as was the Thomson. Rdd=1.9e12 n/s. Amanda reports that central Te and ne still changing significantly around t=1.0 s. Next shot: start A-coil flattop earlier. Delay DNB until t=1.1 s. Boron shaker will be on, therefore Z-Bolo and Thomson will be off. |
| Jul 15 2003 12:00:54:780PM | 1030715012 | Robert Granetz | Shot 12 -- Plasma. Good shot. Locked mode did not start until after the DNB fired. So this is essentially a repeat of shot 004. Rdd=1.5-1.6 n/s. Next shot: repeat one last time with these settings. |
| Jul 15 2003 12:13:18:237PM | 1030715013 | Robert Granetz | Shot 13 -- Plasma. Good shot. Had a locked mode at the DNB time. Density is still changing a tiny amount. Rdd=1.6e12 n/s. Next shot: turn on RF (with a notch programmed in). Disable the A-coils. Boron will be shaking. |
| Jul 15 2003 12:31:08:530PM | 1030715014 | Robert Granetz | Shot 14 -- Plasma. Good shot. Prf=2 MW, with notch at t=0.95-1.00. Good DNB pulse at t=1.10-1.15. RF gives Rdd of 2e12 n/s, and DNB adds about the same amount. No locked mode, as expected. H-mode starts at t=1.24 s, well after the time we're interested in. Next shot: Try for more RF power. No boron shaker, so Thompson and Z-bolo will be on. |
| Jul 15 2003 12:43:15:020PM | 1030715015 | Robert Granetz | Shot 15 -- Plasma. Good shot. Long EDA H-mode during the DNB pulse, so nl_04 is at 2.0e20 m-2. We think we can still see a DNB increase of roughly 1e12 n/s, but it's really dominated by the RF and by sawteeth (max rate is 1.0e13 n/s. H/D = 8%. Zeff=1.1 . Next shot: turn off RF, decrease nl_04 to 0.5e20 m-2, reverse A-coil polarity and turn back on. |
| Jul 15 2003 01:01:43:233PM | 1030715016 | Robert Granetz | Shot 16 -- Plasma. Good shot. Ohmic. Good DNB pulse. nl_04=0.7e20 m-2. No locked mode. Rdd=2.8e12 m/s. Jim reports no problems with boron coatins on windows. Next shot: try to reduce density some more. Turn on Thomson and Z-bolo for the rest of the run. |
| Jul 15 2003 01:13:22:080PM | 1030715017 | Robert Granetz | Shot 17 -- Plasma. Good shot. Good DNB pulse. nl_04=0.5e20 m-2. Rdd=3.2e12 n/s. No locked mode. Zeff=1.5. Startup nearly didn't make it. Next shot: turn off A-coils. Also add 3 ms to pre-fill puff. |
| Jul 15 2003 01:27:41:870PM | 1030715018 | Robert Granetz | Shot 18 -- Plasma. Good shot. Good beam pulse. Max Rdd=2.4e12 n/s, but there was a large injection at 1 s, which affected a lot of the signals. Locked mode began just before t=1 s. Next shot: repeat, hoping not to get an impurity injection. |
| Jul 15 2003 01:36:52:240PM | 1030715019 | Robert Granetz | Shot 19 -- Fizzle. Next shot: reduce pre-fill puff by 1 ms. |
| Jul 15 2003 01:50:42:590PM | 1030715020 | Robert Granetz | Shot 20 -- Plasma. Good shot. But DNB didn't fire. Locked mode begins at t=1.02 s. Good startup Next shot: try again. No changes |
| Jul 15 2003 02:04:43:720PM | 1030715021 | Robert Granetz | Shot 21 -- Plasma. Disrupted early, at t=0.38 s. DNB didn't fire again. Dexter figured out that the gate valve permissive was turned off, which explains the previous shot as well. Next shot: one more try. |
| Jul 15 2003 02:31:12:620PM | 1030715022 | Robert Granetz | Shot 22 -- Plasma. Disrupted at t=0.85 s, just as a locked mode started. Looks like another impurity injection. Next shot: another 'one more try', no changes. |
| Jul 15 2003 02:39:21:493PM | 1030715023 | Robert Granetz | Shot 23 -- Plasma. Good shot. Good beam pulse. nl_04=0.5e20 m-2. Locked mode starts at t=1.0 s. Rdd=2.5e12 n/s. Next shot: try to do Ian's two shots. Start with nl_04=0.8e20 m-2 and turn off the density and pre-programmed gas at t=0.6 seconds, which should result in a density rampdown. No A-coils for this coming shot. |
| Jul 15 2003 02:52:49:467PM | 1030715024 | Robert Granetz | Shot 24 -- Plasma. Hard disruption at 1.52 s. Locked mode at t=1.1 s, just when the beam fires. Rdd=2.8e12 n/s. I think this was a midplane disruption. Density did not ramp down exactly as wanted. Next shot: similar, but start the densty rampdown at nl_04=0.6e20 m-2, try try and get lower. Still no A-coils. |
| Jul 15 2003 03:06:34:723PM | 1030715025 | Robert Granetz | Shot 25 -- Plasma. Hard disruption at t=1.17 s. Density ramped down very low, as desired. Locked mode begins at t=0.84 s. Good DNB pulse. Rdd=2.3e12 n/s. Next shot: repeat, but with A-coils turned on for nearly the entire shot. |
| Jul 15 2003 03:14:47:610PM | 1030715026 | Robert Granetz | Shot 26 -- Fizzle. Disruption recovery? Next shot: take 1 ms off of the pre-fill puff |
| Jul 15 2003 03:44:28:813PM | 1030715027 | Robert Granetz | Shot 27 -- Plasma. Disrupted at t=1.41 s. But we succeeded in preventing a locked mode, so whatever caused the disruption, it wasn't due to a locked mode. End of Ian's shots. Next shot: start a Btor rampdown investigation to see if higher ratio of Error field to Btor makes a difference to DNB neutron production. Re-load segment 2 from shot 004, reduce nl_04 to 0.8e20 m-2, ramp Btor down to 4 T early in shot and then hold there. Turn off A-coils. |
| Jul 15 2003 03:55:11:343PM | 1030715028 | Robert Granetz | Shot 28 -- Plasma. Disrupted at t=0.88 s. Btor flattens at 4.1 T. q95=3.0 There's a locked mode after t=0.7 s. Next shot: turn on the A-coils, with waveform programmed for the entire shot. If this doesn't improve things, I'll have to increase Btor a little to avoid q95=3 |
| Jul 15 2003 04:08:38:350PM | 1030715029 | Robert Granetz | Shot 29 -- Plasma. Good shot. No locked mode. Good DNB pulse. q95=3.0. nl_04=0.85e20 m-2. Got an ohmic H-mode late in the shot. Next shot: repeat, except reduce the density to nl_04=0.6e20 m-2. |
| Jul 15 2003 04:31:01:510PM | 1030715030 | Robert Granetz | Shot 30 -- Plasma. Good shot. No locked modes, but multiple ELMfree H-modes, including during the DNB pulse. Rdd increase is about 1.2e12 n/s, since the density is high due to the H-mode. Next shot: let's explore a different plasma current. Go to 0.6 MA, Btor=5.4 T, nl_04=0.6e20 m-2. A-coils off. |
| Jul 15 2003 04:43:11:200PM | 1030715031 | Robert Granetz | Shot 31 -- Plasma. Good shot. No locked mode. I forgot to tell Amanda to change the grating back. Ip=0.6 MA, Btor=5.4 T, nl_04=0.67e20 m-2. Good beam pulse. Rdd=1.8e12 n/s. This is somewhat lower than shot 16 at 1 MA. Next shot: repeat, this time with central GPC. |
| Jul 15 2003 04:52:55:340PM | 1030715032 | Robert Granetz | Shot 32 -- Plasma. Good shot. No locked mode. Perhaps some little H-modes, but not during the DNB pulse. Ip=0.4 MA. Rdd=1.0e12 n/s. Next shot: reduce plasma current to 250 kA. |
| Aug 5 2003 05:03:07:367PM | 1030715033 | Robert Granetz | Shot 33 -- Plasma. Good shot. Some kind of dithering or marfing throughout
most of the shot. Good DNB pulse. Ip=250 kA, Btor=5.4 T, nl_04=0.7e20 m-2. Rdd=0.7e12 n/s. |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 09:00:12:567AM | Plasma | Ok | |
| 2 | 09:16:29:920AM | Plasma | Ok | |
| 3 | 09:29:10:197AM | Plasma | Ok | |
| 4 | 09:42:34:537AM | Plasma | Ok | |
| 5 | 09:57:42:640AM | Plasma | Bad | NO TF |
| 6 | 10:10:12:917AM | Plasma | Ok | |
| 7 | 10:23:06:740AM | Plasma | Ok | |
| 8 | 10:47:25:857AM | Plasma | Ok | |
| 9 | 11:00:27:657AM | Plasma | Ok | |
| 10 | 11:14:44:867AM | Plasma | Ok | |
| 11 | 11:30:18:827AM | Plasma | Ok | |
| 12 | 11:48:45:280AM | Plasma | Ok | |
| 13 | 12:02:12:940PM | Plasma | Ok | |
| 14 | 12:16:58:337PM | Plasma | Ok | |
| 15 | 12:31:15:640PM | Plasma | Ok | |
| 16 | 12:50:41:280PM | Plasma | Ok | |
| 17 | 01:04:39:003PM | Plasma | Ok | |
| 18 | 01:18:30:277PM | Plasma | Ok | |
| 19 | 01:31:25:107PM | Plasma | Ok | |
| 20 | 01:44:20:923PM | Plasma | Ok | |
| 21 | 01:57:41:133PM | Plasma | Ok | |
| 22 | 02:11:02:107PM | Plasma | Ok | |
| 23 | 02:25:48:287PM | Plasma | Ok | |
| 24 | 02:41:27:840PM | Plasma | Ok | |
| 25 | 02:56:16:427PM | Plasma | Ok | |
| 26 | 03:09:15:960PM | Plasma | Ok | |
| 27 | 03:22:15:607PM | Plasma | Ok | |
| 28 | 03:43:06:480PM | Plasma | Ok | |
| 29 | 04:00:01:367PM | Plasma | Ok | |
| 30 | 04:13:00:683PM | Plasma | Ok | |
| 31 | 04:29:46:303PM | Plasma | Ok | |
| 32 | 04:43:40:090PM | Plasma | Ok | |
| 33 | 04:58:11:613PM | Plasma | Ok | |