| Miniproposals | ||||||||||
|
| Operators | |
| Session leader(s): | Bruce Lipschultz |
| Physics operator(s): | Jim Irby |
| Engineering operator(s): | Andy Pfeiffer,Ed Fitzgerald,Gary Dekow,Gary Dekow |
| Engineering Operator Run Comment |
| MP 417: Boronization Evaluation Session leader: Lipschultz Physics opera |
| Session Leader Plans |
| Entered: Jun 29 2005 08:58:22:647AM |
| Author: Bruce Lipschultz |
| MP 417: 'Plasma performance, boronization and ICRF heating effectiveness with high-Z antenna guards and all-metal walls'
Boronization: scan from 50 to 80 cm with dwell at 52 cm use standard amount of diborane (120 psi) 4 hours Helium ECDC at 5e-5 Torr following boronization 1 hour of D2 ECDC at 2e-4 Torr following Helium ECDC Start with reload of shot 1050620025 - modulo nl04 =0.8, outer gap > 1.5 cm 1) Initial shots all USN - try to make sure the strike point varies with time. Up to 12 shots. RF pulselength ~ 0.5 s unless longer pulses need to condition. Monitor core Mo and Ti for comparison to later shots. 2) When the RF is up to power (min 3 MW, but better up to 4) then switch to LSN, a shot like 1050622014. Check the strike point location. If too constant move it. Take 3-5 shots to evaluate performance. May request a full power on pulse with rf dropping from max to 1.5 MW after 0.5 seconds to evaluate confinement at different powers. 3) Move strike point down vertical plate shot to shot, looking for any changes in Mo sources and core Mo levels. Eventually end on the floor but still sweeping across the floor in time. 4) If the boronization is 'no good', switch to salt shaker evaluation. Diagnostics: NINJA and Chromex needed right away on 486nm, switching to 405 for upper null shot and for most LSN shots. PCI with extended window of measurement for information on QC mode 'intensity' and frequency band width. McPherson on Mo & Ti gate valves closed unless an issue. |
| Physics Operators Plans |
| Entered: Jun 28 2005 01:15:02:793PM |
| Author: Jim Irby |
| Engineering setup for Wednesday, 29 June 2005
MP 417: Boronization Evaluation Session leader: Lipschultz Physics operator: Irby Boronization: scan from 50 to 80 cm with dwell at 52 cm use standard amount of diborane (120 psi) 4 hours Helium ECDC at 5e-5 Torr following boronization 1 hour of D2 ECDC at 2e-4 Torr following Helium ECDC Run begins at 09:00 and ends at 17:00. Engineering setup as on 1050620025 The gatevalves should be setup to toggle closed --- bypass at 160 clicks 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 2 psi Ar Hybrid disabled (PG1) leave B-side upper alone fill B-main (C-side) with 40 psi D2 Hybrid enabled (PG3) fill NINJA with 10 psi D2 Enable the following gate valves: ECE, VUV, Z-bolo shutters ICRF Setup: All transmitters in run on at 8:30 |
| Session Leader Summaries |
| Entered: Jun 29 2005 06:26:21:667PM |
| Author: Bruce Lipschultz |
| MP#417 'Plasma performance, boronization and ICRF heating effectiveness with high-Z antenna guards and all-metal walls'
The day was generally successful. We had difficulty getting going. The first half of the day was spent trying to get past fizzles, duds, and injections. The second half of the day was very successful in that we achieved very steady state H-modes - some wwith H-factors in the 1.7-1.8 range. Results: - The RF appeared to condition up more quickly than usual (opinion of Wukitch and Lipschultz). We did the conditioning at nl04=0.8e20. - The ramp on the rf power did appear to help both in terms of impurities and getting the RF up to full power without faults. - Slightly smaller outer gap and higher density increased the reliability of the RF power (reduced faults) by lowering the antenna voltage. - the slightly higher density (nl04=1.2 as opposed to nl04=1.0) led to a dramatic drop in total radiation and Mo radiation. For example from shot 22 to 23 the density went up from 1. to 1.2 and the Mo radiation dropped by a factor of 2. The total radiation (foil array) dropped from 1.5 to 1.0 MW, so not as much as the Mo. I note that the radiation on shot 23 rose much slower than on 22 as well. - Raising the density before H-mode even more had no deleterious effect. Shot 25 actually had slightly higher stored energy than shot 23 but had the initial density of 1.4 (nl04). - Adding Ar did seem to lead to degradation in confinement and increases in radiation. Shots 26 - 27 followed a great shot (25) and were much poorer. Shots 28 & 30, after the Ar was turned off, were better, although not quite all the way back to 25 (same density). Injections took time to recover from. - QC modes were observed in all H-mode shots with pre-H-mode densities >=1. The QC characteristics (intensity, width of the QC peak) should be correlated with 'goodness' of H-mode. - The boronization of just the divertor was similar to that obtained on 6/22 and 6/10 for similar densities. Namely, the H-modes were generally not so steady state (e.g. shot 17). Shot 19 was at nl04 =1 and the confinement was H slightly > 1. Unfortunately, we have not done a density scan on those previous post-boronization days. Generally it would seem we should be aiming our operation to higher density. This may be helpful in keeping the Mo down by affecting the transport (the pedestal) and/or the source. Given the pumpout of impurities today it appeared that impurity confinement times were of order 100 ms (e.g. shot 24). This seems short and beneficial. - After the impurities pump out, following an injection, the stored energy still needs at least a confinement time to recover - e.g. shot 24. - strike point on the floor does not seem to be very good for impurities or confinement - e.g. shots 15, 31 & 33. This may be due to the fact that moving the x-pt in to get the strike point on the floor leads to more interaction with the inner divertor nose. Some intermediate step should be tried. - Strike point in USN had a lower than ususal H mode threshold (as low as 2.3 MW total power was seen) today. The H-modes appeared to be ELM-free but we did not try higer density and so we do not know whether the confinement might have rivaled LSN. I note that shot 14 had high H factor ~ 2 - 2.2. So this should be explored further. To do - We need to do more with the strike point position, taking into account the interaction with the inner nose. USN plasmas at high density are needed. It would be good to repeat one of the previous boronizations (e.g. outer limiter but full boronization time) and look at confinement at higher densities. - Analyze QC mode characteristics for today (and other post-boronization runs) for correlation with H-mode characteristics. - Since these good confinement shots are at higher density (before H-mode) than years ago we need to compare both the final and pre-H--mode densities with those achieved years ago. Also compare the midplane and divertor pressures. Aside - certainly the compression ratios are lower now and we could look at fixing this during the next break. |
| Physics Operator Summaries |
| Entered: Jun 29 2005 06:01:24:153PM |
| Author: Jim Irby |
| Boronization recovery was not easy today. It took several tries to get the pressure right by shot 4 which finally ran (upper null discharge). The nl_04 request was 8e19/m^2 but the density continued to rise to 1.3e20/m^2. It took two more discharges and a couple of fizzles to gain density control (after shot 8). A couple of disruptions also helped remove some gas. The prefill pressure continued to rise during a large fraction of the run and I had to drop it on most shots, eventually working my way down to an 18 to 20 ms pulse. The rf antennas conditioned pretty quickly in an upper null configuration. When we went to lower null discharges and raised the density to 1.2e20/m^2 we began to get very good sustained h-modes with Wp of up to 203 kJ.
Engineering systems were very reliable today and most problems can be blamed on the physics operator. |
| Session Leader Comments | |||
| Jun 29 2005 09:25:16:877AM | 1050629001 | Bruce Lipschultz | fizzle |
| Jun 29 2005 09:43:40:040AM | 1050629002 | Bruce Lipschultz | dud |
| Jun 29 2005 10:10:15:727AM | 1050629003 | Bruce Lipschultz | dud |
| Jun 29 2005 10:11:45:790AM | 1050629004 | Bruce Lipschultz | Got USN plasma. Density ramping up with no gas injection.
Got very little power. Next shot we hope the density is lower. |
| Jun 29 2005 10:17:13:070AM | 1050629005 | Bruce Lipschultz | fizzle |
| Jun 29 2005 10:37:34:580AM | 1050629006 | Bruce Lipschultz | fizzle |
| Jun 29 2005 10:55:43:957AM | 1050629007 | Bruce Lipschultz | Another USN plasma. More RF power - 1.5 MW. Density rising beyond our control.
The midplane pressure is steadily rising after the RF start. The upper divertor pressure exactly tracks the midplane pressure. It should be higher (USN) indicating that the gas is generated at the midplane - even though we did not boroniza the antennas! |
| Jun 29 2005 11:21:10:690AM | 1050629008 | Bruce Lipschultz | Another USN plasma. More RF power - 2.5 MW. Plasma disrupted at ~ 1.3 seconds. It appears we had 2 major injections at 1.15 and at the end. |
| Jun 29 2005 11:47:42:020AM | 1050629010 | Bruce Lipschultz | Disruption again due to an injection. Had an early injection as well at .12s. |
| Jun 29 2005 12:05:33:280PM | 1050629011 | Bruce Lipschultz | Had an early injection again but the plasma made it. Plasma goes into H-mode at 2.5 MW ehich causes E port antenna to trip. |
| Jun 29 2005 12:22:06:397PM | 1050629012 | Bruce Lipschultz | Early injection again but smaller. Large injection at 0.9s kills the plasma. |
| Jun 29 2005 12:33:19:410PM | 1050629013 | Bruce Lipschultz | fizzle |
| Jun 29 2005 12:45:06:607PM | 1050629014 | Bruce Lipschultz | OK last shot at USN. 2 H-modes. First 166 kJ at 2.5 MW (H-factor >2). Second H-mode of 155 kJ at the same power (H~2). Each H-mode ended by radiation. |
| Jun 29 2005 01:23:32:577PM | 1050629015 | Bruce Lipschultz | LSN H mode. Strike point down in the slot. 130 kJ at 2.5 MW RF so poorer confinement (H ~ 1.3). Radiation was not high for this case! Next shot to strike point on outer divertor.
Poor confinement with low radiation. |
| Jun 29 2005 01:19:46:450PM | 1050629016 | Bruce Lipschultz | LSN H mode. Strike point on the outer divertor. 130 kJ at 2.5 MW RF with numerous injections. Best shot so far USN H-mode. |
| Jun 29 2005 01:50:17:140PM | 1050629018 | Bruce Lipschultz | LSN H mode. Strike point on the outer divertor. 160 kJ at 3 MW until injection kills it. H factor ~ 1.5. Very little or no QC modes according to PCI. |
| Jun 29 2005 02:17:04:123PM | 1050629019 | Bruce Lipschultz | nl04 changed to 1.0. Fairly steady state H-mode with 3 MW RF. Stored energy and confinement drop as radiation rises. SOme QC mode 0.9 - 1.2 sec according to PCI. |
| Jun 29 2005 02:18:02:717PM | 1050629020 | Bruce Lipschultz | nl04=1 before H-mode.
Changed the outer gap by 2 mm to increase the loading on the RF and decrease voltages (less trips is the hope). This seems to have helped. Fairly steady state H-mode again with 3 MW RF. Stored energy drops slightly from 163-153 kJ. H-factor comes down to 1.4. SOme QC mode 0.85 - 1.2 sec according to PCI. |
| Jun 29 2005 02:47:35:403PM | 1050629021 | Bruce Lipschultz | Very steady state H-mode again with 3.3 MW RF. Got QC mode the entire time. Ramped down the power starting at 1.2 s. The stored energy of course comes down (along with the radiation) but the H-factor, which had been very constant at 1.4, comes down too.
|
| Jun 29 2005 02:48:44:747PM | 1050629022 | Bruce Lipschultz | Another very steady state H-mode again 3.3 MW RF. Got QC mode the entire time. Very constant H-factor at 1.4. |
| Jun 29 2005 03:05:50:543PM | 1050629023 | Bruce Lipschultz | nl04 =1.2 target density. Density drops to 1.0 when the RF comes on - RF pumpout.
Stored energy =195 kJ. H=1.7. P_RF=3.7MW. So higher density lowers the radiated power and allows better confinement. Again, we get dropping H-factirs as the RF power is ramped down. |
| Jun 29 2005 03:22:46:993PM | 1050629024 | Bruce Lipschultz | nl04 =1.2 target density. Density drops to 1.1 when the RF comes on - RF pumpout.
An early injection takes till 1.1 s to pump out. The energy rises at the same time. The H-factor rises more slowly reaching 194 kJ and H=1.7. A final injection (Mo) knocks it out of H-mode. |
| Jun 29 2005 03:30:32:977PM | 1050629025 | Bruce Lipschultz | nl04 =1.4 target density. Density deos not drop when the RF comes on - No RF pumpout.
Radiated power about the same. Stored energy over 200 kJ and H~ 1.8. |
| Jun 29 2005 03:44:17:493PM | 1050629026 | Bruce Lipschultz | nl04 =1.4 target density. An initial injection keeps the confinement down. But this time it does not recover. So an aaexample of poor confinement with low radiated power. Note that the Ar was turnd on this shot by the radiated power late in the shot was low so it should not be a factor. |
| Jun 29 2005 04:10:49:383PM | 1050629027 | Bruce Lipschultz | nl04 =1.2 target density. Radiation higher, stored energy lower (155 kJ) and H factor lower - 1.35. Repeat again without Ar. |
| Jun 29 2005 04:16:18:053PM | 1050629028 | Bruce Lipschultz | nl04 =1.2 target density. No Ar puff. Radiation dropped back a bit (1.25 MW), stored energy higher (180 kJ) and H factor higher - 1.55. Repeat again to see if the stored energy goes back up again. |
| Jun 29 2005 04:35:20:820PM | 1050629029 | Bruce Lipschultz | fizzle |
| Jun 29 2005 04:46:06:570PM | 1050629030 | Bruce Lipschultz | nl04 ~ 1.2. Radiation dropping through shot after initial injection and stored energy appraching 175 kJ. Need loonger shot. Next shot strike point on the floor. |
| Jun 29 2005 05:14:54:180PM | 1050629032 | Bruce Lipschultz | fizzle |
| Jun 29 2005 05:16:17:100PM | 1050629033 | Bruce Lipschultz | LSN with strike point in the slot again (by accident). Radiation high and confinement poor. |
| Physics Operator Comments | |||
| Jun 29 2005 09:22:24:287AM | 1050629001 | Jim Irby | loaded shot 1050620029 into PCS --- upper null shot enabled in seg 3
loaded shot 1050628031 into seg 1 adjusted density to 0.8e20 / m^2 pg1 (argon) should be disabled, but I also dropped request to 10 from 100 V I have asked that the RGA be online for the first shot, but we could lose the filament very soon. fizzle --- breakdown early compared to yesterday, but in fact more normal --- broad h-alpha spike --- no burn out very low CIII signal pressure good, fields look good |
| Jun 29 2005 09:40:58:440AM | 1050629002 | Jim Irby | Dropped prefill from 26 to 24 ms
dud! gas now too low |
| Jun 29 2005 09:53:45:767AM | 1050629003 | Jim Irby | prefill to 27 ms
dud again --- |
| Jun 29 2005 10:11:31:087AM | 1050629004 | Jim Irby | prefill increased another 2 ms to 30
plasma at last slow but uneventful current rise density not under control --- got to 1.4e20 NINJA makes small blip at 0.7 s 1.5 MW injection at 1.2 s or so, otherwise prad < 200 kW ssep 1.5 to 1.0 right gap a little large, around 1.6 to 1.7 cm left gap good at 1.5 cm h/(h+d) between 0 and 2% polarimeter NL looks great. BIII up a factor of 3 relative to yesterday, but much higher density |
| Jun 29 2005 10:20:12:090AM | 1050629005 | Jim Irby | no DCPS changes
fizzle --- I'm sure this was predictable pressure too high now? fields are good |
| Jun 29 2005 10:37:16:360AM | 1050629006 | Jim Irby | prefill reduced by 1 ms
back to shot 4 prefill pressure but it was a fizzle |
| Jun 29 2005 11:12:57:300AM | 1050629007 | Jim Irby | No DPCS changes
plasma into rampdown polarimeter Bragg cell was off --- water cooling issue, should be okay now still no density control --- density slightly less on this shot gas valve off at 0.4 s, but density continues to rise cell entry to tune up TCI --- should be better |
| Jun 29 2005 11:26:36:877AM | 1050629008 | Jim Irby | no DCPS changes
plasma for 1.37 s --- then big injection density much more under control breakdown a littler earlier --- Br0 drifting down a little shot to shot Bz0 looks great still no polarimeter CO2 signal --- Bragg cell again |
| Jun 29 2005 11:36:16:690AM | 1050629009 | Jim Irby | no DCPS changes
fizzle --- didn't reduce pressure after the disruption pressure was high, breakdown later firewire camera timing off today |
| Jun 29 2005 11:51:43:050AM | 1050629010 | Jim Irby | no DCPS changes
another disruption at 0.8125 s injections at 120 ms and right before disruption |
| Jun 29 2005 12:11:01:480PM | 1050629011 | Jim Irby | reduced prefill by 1 ms to account for disruption (I hope)
plasma into rampdown still early injections (Matt says Ti) --- dust seen on j-port camera BIII signal coming down polarimeter signal back, but more noisy?? |
| Jun 29 2005 12:18:54:993PM | 1050629012 | Jim Irby | no DPCS changes
plasma for 0.912 s, rf up to 3 MW, then injection density rise begins with application of Rf gatevalve toggling enabled --- 160 clicks on bypass pressure high, but still went okay (gatevalves) |
| Jun 29 2005 12:29:43:473PM | 1050629013 | Jim Irby | prefill decreased another ms to account for disruption and gatevalves
fizzle pressure way too high! |
| Jun 29 2005 12:42:27:950PM | 1050629014 | Jim Irby | reduced prefill by 2 ms
plasma into rampdown 165 kJ at 2.5 MW 2.2 MW prad |
| Jun 29 2005 01:01:34:183PM | 1050629015 | Jim Irby | segment 3 off, segment 2 on: LSN, 1 MA
reduced prefill by 1 ms lsn plasma into rampdown srike-point in slot --- will load 1060622014 for next shot |
| Jun 29 2005 01:18:10:590PM | 1050629016 | Jim Irby | loaded shot 1050622014
loaded seg 1 from 1050629015 prefill reduced another ms (23 ms total) plasma into rampdown 126 kJ gaps okay |
| Jun 29 2005 01:33:24:233PM | 1050629017 | Jim Irby | prefill reduced another ms --- 21 ms
plasma into rampdown RF to 3.25 MW for 155 kJ |
| Jun 29 2005 01:46:17:747PM | 1050629018 | Jim Irby | reduced prefill by 1 ms
plasma for .961 s 160 kJ at 3.3 MW right before disruption |
| Jun 29 2005 02:02:21:747PM | 1050629019 | Jim Irby | checked that a-coils are running and they are
nl04 request to 1e20 / m^2 reduced prefill by 1 ms plasma into rampdown --- single extended h-mode 144 kJ for 3.1 MW, 1.77 MW on prad_main nice polarimeter NL |
| Jun 29 2005 02:19:39:327PM | 1050629020 | Jim Irby | increased RCUR a little starting around 0.7 s
reduced prefill by 1 ms plasma into rampdown --- a little hesitation in current rise; gas too low at last 163 kJ for 3.1 MW, nice long eda h-mode h/(h+d) 3 to 4% |
| Jun 29 2005 02:25:37:733PM | 1050629021 | Jim Irby | no DPCS changes
plasma into rampdown 163 kJ for 3.2 MW |
| Jun 29 2005 02:43:01:013PM | 1050629022 | Jim Irby | rcur increased by 0.5 mm
plasma into rampdown did decrease right gap a little nice long h-mode with constant stored energy 164 kJ for 3.3 MW, 1.4 MW prad_main |
| Jun 29 2005 03:00:49:937PM | 1050629023 | Jim Irby | nl04 request to 1.2e20 / m^2
plasma into rampdown 195 kJ, 3.6 MW, 1 MW prad_main, nice constant Wp |
| Jun 29 2005 03:14:41:497PM | 1050629024 | Jim Irby | no DPCS changes
plasma into rampdown j-port trips but still got to 195 kJ at 3.5 MW injection at 1.37 s |
| Jun 29 2005 03:34:39:350PM | 1050629025 | Jim Irby | nl_04 request to 1.4e20 / m^2
plasma into rampdown nice steady h-mode again 203 kJ, 3.6 MW, rad about 1 MW |
| Jun 29 2005 03:41:44:053PM | 1050629026 | Jim Irby | argon enabled from 300 to 345 ms
IGT at 4e-6 in check plasma into rampdown 139 kJ, neutral rate way down, injections |
| Jun 29 2005 03:58:27:290PM | 1050629027 | Jim Irby | nl_04 request back down to 1.2e20 /m^2
plasma into rampdown 148 kJ, clean 3.7 MW of rf, but 1.5 MW of radiation |
| Jun 29 2005 04:13:50:710PM | 1050629028 | Jim Irby | disabled argon --- otherwise repeat
IGT 5.6e-6 in check plasma into rampdown parameters look much better |
| Jun 29 2005 04:22:36:087PM | 1050629029 | Jim Irby | reduced gas puff by 2 ms -- no other changes
see if we can get back to 200 kJ IGT at check 4.0e-6 fizzle --- gas too low, fields good |
| Jun 29 2005 04:42:15:913PM | 1050629030 | Jim Irby | prefill increased by 2 ms (where we were on shot 28)
3.1e-6 Torr at pulse plasma into rampdown higher radiated power early, only 175 kJ |
| Jun 29 2005 04:54:53:273PM | 1050629031 | Jim Irby | changed RXL to be the same as 1050629015 --- should put us on the floor
IGT in check 4.4e-6 Torr plasma to 1.15 s |
| Jun 29 2005 05:05:21:007PM | 1050629032 | Jim Irby | loaded shot 14 seg 3 into seg 3 (upper null shot)
increased rcur by 1.5 m reduced prefill by 1 ms (disruption control) fizzle |
| Jun 29 2005 05:21:10:337PM | 1050629033 | Jim Irby | ef4 from -1285 to -1320 A
didn't turn on seg 3 to get the upper null!! disruption at 1.14 --- still in the slot |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 09:16:51:947AM | Plasma | Ok | |
| 2 | 09:30:21:250AM | Plasma | Ok | |
| 3 | 09:44:46:010AM | Plasma | Ok | |
| 4 | 09:57:28:847AM | Plasma | Ok | |
| 5 | 10:12:27:400AM | Plasma | Ok | |
| 6 | 10:25:12:763AM | Plasma | Ok | |
| 7 | 10:38:05:563AM | Plasma | Ok | |
| 8 | 11:11:05:487AM | Plasma | Ok | |
| 9 | 11:25:01:143AM | Plasma | Ok | |
| 10 | 11:37:34:940AM | Plasma | Ok | |
| 11 | 11:55:01:433AM | Plasma | Ok | |
| 12 | 12:11:00:510PM | Plasma | Ok | |
| 13 | 12:23:41:833PM | Plasma | Ok | |
| 14 | 12:36:39:750PM | Plasma | Ok | |
| 15 | 12:52:40:450PM | Plasma | Ok | |
| 16 | 01:09:49:260PM | Plasma | Ok | |
| 17 | 01:23:16:763PM | Plasma | Ok | |
| 18 | 01:36:12:187PM | Plasma | Ok | |
| 19 | 01:49:54:967PM | Plasma | Ok | |
| 20 | 02:05:31:030PM | Plasma | Ok | |
| 21 | 02:18:23:123PM | Plasma | Ok | |
| 22 | 02:31:54:857PM | Plasma | Ok | |
| 23 | 02:48:01:780PM | Plasma | Ok | |
| 24 | 03:04:43:687PM | Plasma | Ok | |
| 25 | 03:20:16:150PM | Plasma | Ok | |
| 26 | 03:35:50:180PM | Plasma | Ok | |
| 27 | 03:49:51:587PM | Plasma | Ok | |
| 28 | 04:02:23:790PM | Plasma | Ok | |
| 29 | 04:17:52:993PM | Plasma | Ok | |
| 30 | 04:30:28:257PM | Plasma | Ok | |
| 31 | 04:44:53:337PM | Plasma | Ok | |
| 32 | 04:58:40:243PM | Plasma | Ok | |
| 33 | 05:11:56:290PM | Plasma | Ok | |