| Miniproposals | ||||||||||
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| Operators | |
| Session leader(s): | Jim Irby,Marco Ferrara |
| Physics operator(s): | Earl Marmar |
| Engineering operator(s): | Gary Dekow,Bill Byford |
| Engineering Operator Run Comment |
| MP 298A C-Mod Plasma Startup SL: Irby, PO: , EO: Pierson |
| Session Leader Plans |
| Entered: Feb 10 2005 08:26:23:113AM |
| Author: Jim Irby |
| Continue conditioning machine. Startup from 1050209021 Run inner wall limited discharges followed by discharges that sweep from lower null to upper null. Monitor h/d, radiation, etc. Enable toggling of gatevalves --- GV1 should be manually closed at the beginning of INIT |
| Entered: Feb 10 2005 11:47:37:000AM |
| Author: Marco Ferrara |
| During the second half of the run, we'll be using the Digital Plasma Control System (DPCS) with the following goals: 1) Reduce DPCS cycle rate until problems with position control appear. This allows us to determine the maximum cycle time and headroom for extra computation; 2) Increase DPCS cycle rate to the point at which samples are lost and verify that plasma control with the current implementation of DPCS is robust against lost samples |
| Physics Operators Plans |
| Session Leader Summaries |
| Entered: Feb 10 2005 07:11:49:990PM |
| Author: Marco Ferrara |
| Shot 1050210021 run at 10kHz: successful control of a rather unstable plasma. Shot 1050210022 run at 5kHz: successful control of the plasma. Z trace looks much similar to 021. Shot 1050210023 run at 2.5kHz: Lost control and disruption. Interesting z traces show the typical exponentially growing instability. Shots 024 and 025 were run at 300us, but resulted in fizzles. DPCS managed to control the plasma down to 200us cycle time. Which means we have at least an additional 100 us for computation for similar sorts of plasmas. The cycle time is now back at 100us. |
| Entered: Feb 11 2005 10:23:37:637AM |
| Author: Jim Irby |
| We continued the vessel cleanup today by running a couple of inner wall limited plasmas (shots 13 and 14). Density, ciii, halpha, h/d all went up. Still have not reached wall conditions in which gas puffing is required to maintain the density above 5e19. We did not have time to sweep from SNL to SNU. |
| Physics Operator Summaries |
| Entered: Feb 10 2005 07:16:22:030PM |
| Author: Earl Marmar |
| Plan: During the first half of the run we will complete the MP298a cleanup tasks including inner wall limited and upper null cases. We will complete MP399 during the remainder of the run (checkout of DPCS). Results: Got some of the plan accomplished. We ran a number of LSN shots with sweeps, most with no segment 2 gas puff. Then we ran a few inner-wall limited shots, including 1 at 1.0 MA that disrupted at the end of flattop (power supplies reached limits). The DPCS part of the run had the last part of the run, getting three good discharges, including shot 23 where the VDE appeared to be caused by loss of control due to the purposeful slowing of the DPCS cycle time. Disruptions were all followed by fizzles. The main attempt to help this was to dramatically decrease the prefill pressure. By the end of the run, it was down to 11 ms. Nevertheless, the last 2 shots fizzled. Summary: 14 Plasmas 10 fizzles 1 no power cycle (communication failure right before pulse) |
| Session Leader Comments | |||
| Feb 10 2005 04:07:14:100PM | 1050210013 | Jim Irby | Density, halpha, pressure, cii, all up as we moved plasma near innner wall. |
| Feb 10 2005 04:21:26:763PM | 1050210014 | Jim Irby | Earl claims solid inner wall limited plasma higher density, ciii, etc, rise than shot 13. A little more gas evolved. h/(h+d) actually down from shot 13 to 42% |
| Feb 10 2005 06:18:46:617PM | 1050210018 | Marco Ferrara | Shot run at 10kHz DPCS cycle rate. fizzle. |
| Feb 10 2005 06:22:02:967PM | 1050210019 | Marco Ferrara | Shot run at 10kHz DPCS cycle rate. Early disruption at 1.3s. |
| Feb 10 2005 06:22:20:847PM | 1050210020 | Marco Ferrara | Shot run at 10kHz DPCS cycle rate. Fizzle. |
| Feb 10 2005 06:23:13:143PM | 1050210021 | Marco Ferrara | Shot run at 10kHz DPCS cycle rate. Full plasma, with a growing vertical instability. |
| Feb 10 2005 06:28:12:100PM | 1050210022 | Marco Ferrara | Shot run at 5kHz DPCS cycle rate. Full plasma, very similar to 021 as far as vertical control. |
| Feb 10 2005 06:44:41:503PM | 1050210023 | Marco Ferrara | Shot run at 2.5kHz DPCS cycle rate. Lost vertical control. Very nice z traces exponentially diverging at 0.56s. |
| Feb 10 2005 06:50:03:513PM | 1050210024 | Marco Ferrara | Shot run at 3.3kHz DPCS cycle rate. fizzle. |
| Feb 10 2005 07:05:39:233PM | 1050210025 | Marco Ferrara | Shot run at 3.3kHz DPCS cycle rate. fizzle. |
| Physics Operator Comments | |||
| Feb 10 2005 11:41:33:737AM | Earl Marmar | During the first half of the run we will complete the MP298a cleanup tasks including inner wall limited and upper null cases. We will complete MP399 during the remainder of the run (checkout of DPCS). | |
| Feb 10 2005 12:33:32:440PM | 1050210001 | Earl Marmar | load segment 1 from first good shot yesterday (1050209004) load segment 2 from last shot yesterday (1050209021) remove a-coil program points after 2.5 seconds to reduce amount of data stored turn nl_04 demand down to 2.3e19, to see what happens without any gas puff in segment 2; voltage demand for PG3 was already 0 plasma good l-mode shot (H89 close to 1 throughout) H/(H+D) ~ .18 |
| Feb 10 2005 12:45:13:473PM | 1050210002 | Earl Marmar | tweak EFC segment 2 voltage command (to 0 from 100 volts) (Wolfe suggestion) no other pcs changes plasma EFC looks happier H/(H+D) between .2 and .25 |
| Feb 10 2005 01:11:08:520PM | 1050210003 | Earl Marmar | data system hang during init no power cycle shot counter not incremented, so next attempt will also be shot 3 |
| Feb 10 2005 01:13:48:393PM | 1050210003 | Earl Marmar | enable argon (PG1, 75 ms pulse width) no pcs changes plasma H/(H+D) ~ .25 to .3 |
| Feb 10 2005 02:04:09:310PM | 1050210004 | Earl Marmar | nl_04 prog up to 7e19, to puff some gas had a long delay for cell entry before the shot plasma got the density a little RF from E port (short, 40 kW pulses) H/(H+D) ~ .22 |
| Feb 10 2005 02:23:24:503PM | 1050210005 | Earl Marmar | turn off the gas puff at 1.0 seconds (nl_04 program goes negative at that time) plasma, early disruption (~.5 seconds) |
| Feb 10 2005 02:32:40:003PM | 1050210006 | Earl Marmar | turn off nl_04 feedback gain reduce prefill puff by 3 ms (to 21 ms) preprogram small maintenance on PG3 (~20) between 0.1 and 1.0 seconds fizzle lots of z-meter light; essentially no Ip |
| Feb 10 2005 02:38:22:487PM | 1050210007 | Earl Marmar | reduce prefill another 3 ms, to 18 ms fizzle |
| Feb 10 2005 03:04:06:380PM | 1050210008 | Earl Marmar | reduce prepuff another 2 ms to 16 ms fizzle still almost no Ip |
| Feb 10 2005 03:07:47:037PM | 1050210009 | Earl Marmar | no changes fizzle |
| Feb 10 2005 03:23:53:657PM | 1050210010 | Earl Marmar | reduce prepuff another 2 ms to 16 ms plasma short and brutish; could be a tad dirty |
| Feb 10 2005 03:36:43:253PM | 1050210011 | Earl Marmar | reduce prefill another 1 ms (to 13 ms) reduce segment 1 gas puff early turn off segment 2 gas puff some kind of engineering problem (network, PLC)? just before pulse. No power shot. |
| Feb 10 2005 03:49:58:767PM | 1050210012 | Earl Marmar | no pcs changes plasma, full length 100 kW RF pulse H/(H+D) ~ .45 |
| Feb 10 2005 04:03:41:583PM | 1050210013 | Earl Marmar | increase prepuff by 1 ms to 14 ms inner wall limited: reduce RCUR by .01 m reduce CLEARIN by .02 m plasma got higher density inner gap ~2 mm, rising to ~4mm near end of flattop H/(H+D) ~ 0.5 |
| Feb 10 2005 04:26:09:500PM | 1050210014 | Earl Marmar | decrease CLEARIN another 10 mm decrease RCUR another 5 mm smooth out the RXL and ZXL sweeps plasma well limited on the inner wall H/(H+D) ~ .45 nl04 is approaching 9e19 with no segment 2 D2 puff |
| Feb 10 2005 04:26:40:170PM | 1050210015 | Earl Marmar | Ip prog to 1.0 MA increase RCUR .001 m fizzle |
| Feb 10 2005 04:47:19:260PM | 1050210016 | Earl Marmar | reduce prepuff by 1 ms plasma 1 MA shot disrupts at end of flattop (OH2's at PLC limit, EF1U at the rail after 1 second) nl04 to 1.1e20 (still no puff in segment 2) H/(H+D) ~ 0.45 |
| Feb 10 2005 04:56:55:340PM | 1050210017 | Earl Marmar | lower prefill puff to 12 msec Ip to 0.8 MA ZXU reduced to 4 cm (from 6 cm) fizzle |
| Feb 10 2005 05:16:59:410PM | 1050210018 | Earl Marmar | switching to the MP399 Digital Plasma Control System checkout load segment 2 from 1050209008 fizzle |
| Feb 10 2005 05:30:17:150PM | 1050210019 | Earl Marmar | no pcs changes plasma disrupt at 1.3 s early runaways |
| Feb 10 2005 05:39:23:357PM | 1050210020 | Earl Marmar | put back some of the segment 1 D2 gas puff turn on nl04 feedback, gain = 8 nl_04 prog to 5e19 fizzle |
| Feb 10 2005 06:20:38:477PM | 1050210021 | Earl Marmar | reduce BR0 offset by 0.5 mTesla (make it more negative) plasma, ramped all the way down H/(H+D) ~ .45 |
| Feb 10 2005 06:29:55:173PM | 1050210022 | Earl Marmar | add a little more D2 puff after 50 ms keep density demand on to end of flattop plasma, ramps all the way down H/(H+D) ~ .35 |
| Feb 10 2005 06:50:48:370PM | 1050210023 | Earl Marmar | no pcs changes DPCS cycle rate being slowed, expect to lose vertical control at some point when the rate is too slow plasma; disrupt at 0.6 seconds H/(H+D) ~ .4 to .5, rising to 0.8 at the disruption |
| Feb 10 2005 06:51:01:903PM | 1050210024 | Earl Marmar | no pcs changes fizzle |
| Feb 10 2005 07:03:49:000PM | 1050210025 | Earl Marmar | decrease prepuff by 1 ms (to 11 ms) fizzle |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 12:18:53:037PM | Plasma | Ok | |
| 2 | 12:35:06:113PM | Plasma | Ok | |
| 3 | 01:07:16:957PM | Plasma | Ok | |
| 4 | 01:51:17:530PM | Plasma | Ok | |
| 5 | 02:10:52:060PM | Plasma | Ok | |
| 6 | 02:24:09:097PM | Plasma | Ok | |
| 7 | 02:36:49:207PM | Plasma | Ok | |
| 8 | 02:49:56:980PM | Plasma | Ok | |
| 9 | 03:02:23:227PM | Plasma | Ok | |
| 10 | 03:14:58:423PM | Plasma | Ok | |
| 11 | 03:29:08:487PM | Plasma | Bad | Ack Failure, Power Supplies Didn't Fire |
| 12 | 03:40:56:540PM | Plasma | Ok | |
| 13 | 03:55:27:020PM | Plasma | Ok | |
| 14 | 04:08:42:227PM | Plasma | Ok | |
| 15 | 04:22:16:107PM | Plasma | Ok | |
| 16 | 04:35:06:300PM | Plasma | Ok | |
| 17 | 04:53:02:087PM | Plasma | Ok | |
| 18 | 05:06:27:263PM | Plasma | Ok | |
| 19 | 05:19:07:630PM | Plasma | Ok | |
| 20 | 05:37:35:120PM | Plasma | Ok | |
| 21 | 06:10:08:727PM | Plasma | Ok | |
| 22 | 06:23:00:530PM | Plasma | Ok | |
| 23 | 06:35:36:640PM | Plasma | Ok | |
| 24 | 06:48:29:753PM | Plasma | Ok | |
| 25 | 07:01:15:913PM | Plasma | Ok | |