| Miniproposals | ||||||||||
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| Operators | |
| Session leader(s): | Spencer Pitcher,Spencer Pitcher |
| Physics operator(s): | Robert Granetz |
| Engineering operator(s): | Frank Silva |
| Engineering Operator Run Comment |
| MP#242/Granetz/Silva |
| Session Leader Plans |
| Physics Operators Plans |
| Session Leader Summaries |
| Entered: Jul 7 2004 03:49:20:743PM |
| Author: To Be Determined |
| Summary for run 990526, MP 242 Right Gap Scan (piggy-back MP 209 flapper) SL S Pitcher PO B Granetz This was a very pain day, trying to obtain plasmas with right gaps greater than 2 cm. Most attempts terminated with vertical instabilities early in the discharge. One shot, shot 23, had a right gap scan from 1 cm to almost 3 cm and then went unstable. Despite the sparse data, it does appear that the right gap influences the midplane pressure (0 cm to 2.5 cm), and to a lesser extent the divertor pressure. The best way of quantifying the effect is in the compression ratio, which varied from CR = 165 with 0 cm right gap to values as high as CR = 270 with right gap 2.5 cm. We took helium probe, FSP and ASP profiles during the day. These profiles, not yet analyzed, should shed light on the interaction of the SOL plasma with the limiters at the outside midplane. This is the factor which presumably primarily determines the outside midplane pressure. We found an anti-intuitive result...with small right gap (e.g. 5 mm) the opening of the flapper has a larger perturbation on the midplane pressure, i.e. 50% effect compared with 15% effect at right gap = 2.0 cm. CSP |
| Physics Operator Summaries |
| Entered: Jul 7 2004 04:37:01:397PM |
| Author: To Be Determined |
| Physics operator summary for run 990526. MP 242 -- Outer gap scan SL: S. Pitcher PO: R. Granetz The goal for today: Study dependence of main chamber neutral pressure on outer gap. Summary: Running with an outer gap of 3.0 cm made the plasma vertically unstable no matter what we did. Reducing the elongation to typical values by lowering ZCUR (keeping x-point constant) didn't seem to help at all. We lost a lot of the day due to commutation problems with the OH2's. During the later hours of the run, the field nulls, as diagnosed, looked awful, but the plasma ran reliably. See session leader's summary for some interesting findings about the compression ratio vs outer gap. Scorecard: 13 plasmas 4 fizzles 1 dud (due to shot cycle/power supply fault) 10 tests 1 aborted ---------- 29 total ------------------------------------------------------------------------------ Engineering Setup for Wednesday, 990526 Load from 990520004 (0.8 MA, 1.4 s long flattop, nl_04=1.0e20 m-2) 1 hour ECDC in D2 prior to run, stopping in time to begin run at 08:00. Gas setup - fill B-top with 6 psi of D2 Hybrid enabled fill B-side lower with 1 psi of Ar Hybrid DISABLED leave B-side upper as is Hybrid DISABLED fill C-side with 30 psi of D2 Hybrid enabled leave J-bottom as is Hybrid DISABLED The following gate valves should be enabled, assuming no vacuum problems: ECE, VUV ------------------------------------------------------------------------------- Run Plan for 990526: MP 242 -- Right gap scan SL: S. Pitcher PO: R. Granetz Start by loading 990520004, an 0.8 MA, long flattop shot from last week. From there, we will want to vary the outer gap (up to 6 cm). The resulting elongation may cause stability problems, so we may have to play with ZCUR. Control of SSEP and ZXU may be attempted, depending on instructions from the session leader. Before the physics run, we will need to do a 'Tuesday' OH test, and perhaps a commutation test as well. ------------------------------------------------------------------------------ Note: 1 hour of ECDC in D2 was done prior to this run. Hybrid coldstart done; no errors found ($set default cmod$models:[hybrid.tcl] $@hybinit_dispatch $@show_bitbus_log Use editor search to verify no occurrences of "error" nor "not respond") Load 990520004. Shot 01 -- OH test (normal 'Tuesday' coax test plus a commutation test. All OK. Next shot: EF4 test (bipolar) at the request of John Heard. Shot 02 -- EF4 test for John Heard. Loaded from 990521005, a pre-programmed bipolar test of EF4 only under hybrid control. Next shot: plasma. Load from 990520004, a long (1.4 s flattop), 0.8 MA shot. Shot 03 -- Test (no power shot; sort of an abort). Apparently after the OH commutation test on shot 01, there was an auto-crowbar on OH2, which wasn't noticed until we init'ed for this shot. Next shot: plasma. Load from 990520004, a long (1.4 s flattop), 0.8 MA shot. Shot 04 -- Fizzle. Very negative Br0 (-3 mT) Next shot: raise Br0 by 0.002 T (from 0.000 to +0.002 T) Shot 05 -- Plasma. Good shot. Ip=0.8 MA, nl_04=1.0e20 m-2, flattop to 1.4 s. Outer gap=1.3 cm. Inner gap=1.5-1.4 cm. Br0 still too negative. Flapper opened at 1.0 s. Next shot: raise Br0 another 1 mT. Also enable argon puff. Also move flapper opening earlier (to t=0.9 s instead of 1.0 s). There was a delay between shots 5 and 6 to fix the OH2 crowbar problem. Shot 06 -- Fizzle. No OH2 commutation. OH2's charged through their resisters; switch must not have closed. Shot 07 -- OH2 commutation test. Switches didn't close and didn't commutate. There is a delay between shot 7 and 8 to work on the OH2 commutation problem. Shot 08 -- Test. OH2 gate signals are not getting down to supply. Shot 09 -- Test. Shot 10 -- Test. Shot 11 -- Test. Shot 12 -- Test. All fixed. Shot 13 -- Test. Final OH2 test, with power. Looks good, except the crowbar problem returned. Shot 14 -- Plasma. Good shot. Same as shot 05, except argon puffed, probe fired, and flapper opened at t=0.8 s. Right gap=1.25 cm. Br0 is still too negative. Next shot: increase right gap to 2.5 cm (reduce RCUR by 6 mm), and increase Br0 offset by another 0.5 mT (to +0.0035) Shot 15 -- Plasma. Good shot. Outer gap=2.0 cm, not 2.5 cm. Elongation rose to 1.7. Argon not puffed. Spencer reports that both F-side and B-bottom pressures were lower on this shot than the previous shot (when flaps are closed). Nice null. Next shot: increase right gap to 3.0 cm. Re-enable argon puff. Shot 16 -- Plasma. Disrupted at 0.53 s due to vertical instability; not unexpected. Outer gap reached 3.0 cm, elongation=1.75-1.8. Next shot: lower Zcur by 10 mm, and move argon puff to t=0.5 s. Shot 17 -- Fizzle. Br0 too high. Next shot: reduce Br0 by 1.5 mT (+0.0035 to +0.002 T). Shot 18 -- Plasma. Disrupted at t=0.55 s. Zcentroid did indeed drop by 1 cm. Elongation was only 1.7. Next shot: lower ZCUR another 1 cm, raise ZXU by 2 cm (S. Wolfe), and turn off argon. Shot 19 -- Plasma. Disrupted at t=0.55 s. Elongation was less than 1.7. EF4 was very close to the PLC limit. Next shot: same, except raise PLC limit from 8 to 8.5 kA Shot 20 -- Plasma. Disrupted at t=0.58 s, same stability problem. Next shot: ramp the gap. Start around t=0.4-0.6 at the RCUR from shot 15, and ramp to the gap on shot 20 at t=1.5 s. Flapper will also be turned off. Shot 21 -- Plasma. Disrupted at t=0.36 s. I think it was a moly injection, not a VDE. Next shot: repeat, no changes. Shot 22 -- Fizzle. Br0 was too positive. Next shot: decrease Br0 offset by 1 mT, and start outer gap ramp at the same value as on shot 5 (and ramp down to the value on shot 20. Shot 23 -- Plasma. Better. Gap scanned from 1.1 to 3.0 cm. Disrupted at t=1.53 s, when the outer gap reached 3.0 cm, even though the elongation was low (because ZCUR was still down by 2 cm). Next shot: re-load shot 05. Also reduce Br0 by another 0.5 mT. Also reduce I_EF4 by 15 amps. Shot 24 -- Plasma. Good shot. Outer gap=1.4 cm. Next shot: decrease outer gap to 3 mm. Also reduce IC_EF4 by another 15 amps, and reduce Br0 by another 0.5 mT. Shot 25 -- Plasma. Good shot. Outer gap=0.5 cm. Next shot: argon puff at t=0.5 s. Also reduce IC_EF4 by another 15 amps, and reduce Br0 by another 0.5 mT. Shot 26 -- Plasma. Good shot. Outer gap=0.5 cm. (The nulls since shot 22 have looked really awful on the mflux plots, but they're still going. This shot may have hit something at 27 ms.) Next shot: reduce gap to 0 cm! Shot 27 -- Aborted (hung up in INIT). Shot 28 -- Dud. Lots of power supplies didn't fire. Shot 29 -- Plasma. Good shot. Marginally limited on outboard limiter for the entire flattop. No obvious problems with molydenum or Prad. Argon puffed at t=0.3 s. Null still looks awful. End of run. |
| Session Leader Comments | |||
| May 26 1999 09:11:33:450AM | 990526005 | Spencer Pitcher | flapper opens 1.0 s (strange flapper voltage wave) density affected by flapper helium beam gas at 0.5 s left gap = 1.4 cm, right gap = 1.4 cm, elongation = 1.66 fside press = 0.19 mTorr no argon -------------------------- |
| May 26 1999 12:36:15:623PM | 990526014 | Spencer Pitcher | "repeat" flapper opens 0.8 s >> effects density helium beam gas at 0.4 s left gap = 1.4 cm, right gap = 1.2 cm, elongation = 1.66 argon fsp,asp -------------------------- |
| May 26 1999 12:46:59:060PM | 990526015 | Spencer Pitcher | flapper opens 0.8 s >> effects density helium beam gas at 0.4 s left gap = 1.4 cm, right gap = 2.0 cm, elongation = 1.71 no argon no fsp,asp -------------------------- |
| May 26 1999 01:20:55:840PM | 990526016 | Spencer Pitcher | disrupts at 0.53 s flapper opens 0.8 s >> effects density helium beam gas at 0.4 s left gap = 1.5 cm, right gap = 2.8 cm, elongation = 1.79 argon no fsp,asp -------------------------- |
| May 26 1999 01:48:56:840PM | 990526018 | Spencer Pitcher | disrupts at 0.55 s flapper opens 0.8 s helium beam gas at 0.4 s left gap = 1.9 cm, right gap = 2.6 cm, elongation = 1.7 argon no fsp,asp -------------------------- fside press is 0.13 mTorr, compression ratio (CR) = 240 these cf with shot 14, right gap = 1.2 cm, fside = .17 mTorr, CR = 190 >>> right gap seems to have influenced midplane pressure somewhat |
| May 26 1999 02:43:16:437PM | 990526019 | Spencer Pitcher | disrupts at 0.56 s flapper opens 0.8 s helium beam gas at 0.4 s left gap = 1.5 cm, right gap = 2.6 cm, elongation = 1.69 no argon no fsp,asp compression ratio = 256 |
| May 26 1999 02:51:44:140PM | 990526020 | Spencer Pitcher | disrupts at 0.58 s flapper opens 0.8 s helium beam gas at 0.4 s left gap = 1.5 cm, right gap = 2.6 cm, elongation = 1.65 no argon no fsp,asp compression ratio = 260 |
| May 26 1999 03:35:13:170PM | 990526023 | Spencer Pitcher | right gap scan, 1 cm to approx 3 cm disrupts in current ramp down when right gap = 2.8 cm no flappers helium beam gas at 0.4 s left gap = 1.5 cm no argon no fsp,asp compression ratio ramps 190 to 270 |
| May 26 1999 03:50:05:233PM | 990526024 | Spencer Pitcher | flappers .8 s helium beam gas at 0.4 s left gap = 1.5 cm, right gap = 1.4 cm no argon no fsp,asp compression ratio 200 |
| May 26 1999 04:06:54:327PM | 990526025 | Spencer Pitcher | flappers .8 s helium beam gas at 0.4 s left gap = 1.5 cm, right gap = 0.5 cm no argon no fsp,asp compression ratio 177 |
| May 26 1999 04:27:16:810PM | 990526026 | Spencer Pitcher | repeat flappers .8 s helium beam gas at 0.4 s left gap = 1.5 cm, right gap = 0.5 cm argon fsp,asp compression ratio 170 |
| May 26 1999 05:14:44:763PM | 990526029 | Spencer Pitcher | flappers .8 s helium beam gas at 0.4 s left gap = 1.5 cm, right gap = 0.0 cm argon fsp,asp compression ratio 165 |
| Physics Operator Comments | |||
| May 26 1999 07:50:21:013AM | Robert Granetz | Engineering Setup for Wednesday, 990526 Load from 990520004 (0.8 MA, 1.4 s long flattop, nl_04=1.0e20 m-2) 1 hour ECDC in D2 prior to run, stopping in time to begin run at 08:00. Gas setup - fill B-top with 6 psi of D2 Hybrid enabled fill B-side lower with 1 psi of Ar Hybrid DISABLED leave B-side upper as is Hybrid DISABLED fill C-side with 30 psi of D2 Hybrid enabled leave J-bottom as is Hybrid DISABLED The following gate valves should be enabled, assuming no vacuum problems: ECE, VUV | |
| May 26 1999 07:50:40:043AM | Robert Granetz | Run Plan for 990526: MP 242 -- Right gap scan SL: S. Pitcher PO: R. Granetz Start by loading 990520004, an 0.8 MA, long flattop shot from last week. From there, we will want to vary the outer gap (up to 6 cm). The resulting elongation may cause stability problems, so we may have to play with ZCUR. Control of SSEP and ZXU may be attempted, depending on instructions from the session leader. Before the physics run, we will need to do a 'Tuesday' OH test, and perhaps a commutation test as well. | |
| May 26 1999 07:50:55:793AM | Robert Granetz | Note: 1 hour of ECDC in D2 was done prior to this run. Hybrid coldstart done; no errors found ($set default cmod$models:[hybrid.tcl] $@hybinit_dispatch $@show_bitbus_log Use editor search to verify no occurrences of "error" nor "not respond") Load 990520004. | |
| May 26 1999 07:52:56:890AM | 990526001 | Robert Granetz | Shot 01 -- OH test (normal 'Tuesday' coax test plus a commutation test. All OK. Next shot: EF4 test (bipolar) at the request of John Heard. |
| May 26 1999 08:06:44:843AM | 990526002 | Robert Granetz | Shot 02 -- EF4 test for John Heard. Loaded from 990521005, a pre-programmed bipolar test of EF4 only under hybrid control. Next shot: plasma. Load from 990520004, a long (1.4 s flattop), 0.8 MA shot. |
| May 26 1999 08:18:45:077AM | 990526003 | Robert Granetz | Shot 03 -- Test (no power shot; sort of an abort). Apparently after the OH commutation test on shot 01, there was an auto-crowbar on OH2, which wasn't noticed until we init'ed for this shot. Next shot: plasma. Load from 990520004, a long (1.4 s flattop), 0.8 MA shot. |
| May 26 1999 08:34:55:890AM | 990526004 | Robert Granetz | Shot 04 -- Fizzle. Very negative Br0 (-3 mT) Next shot: raise Br0 by 0.002 T (from 0.000 to +0.002 T) |
| May 26 1999 08:55:18:920AM | 990526005 | Robert Granetz | Shot 05 -- Plasma. Good shot. Ip=0.8 MA, nl_04=1.0e20 m-2, flattop to 1.4 s. Outer gap=1.3 cm. Inner gap=1.5-1.4 cm. Br0 still too negative. Flapper opened at 1.0 s. Next shot: raise Br0 another 1 mT. Also enable argon puff. Also move flapper opening earlier (to t=0.9 s instead of 1.0 s). |
| May 26 1999 09:26:28:967AM | 990526006 | Robert Granetz | There was a delay between shots 5 and 6 to fix the OH2 crowbar problem. |
| May 26 1999 09:47:39:840AM | 990526007 | Robert Granetz | There is a delay between shot 7 and 8 to work on the OH2 commutation problem. |
| May 26 1999 09:53:33:043AM | 990526007 | Robert Granetz | Shot 07 -- OH2 commutation test. Switches didn't close and didn't commutate. |
| May 26 1999 10:17:52:623AM | 990526008 | Robert Granetz | Shot 08 -- Test. OH2 gate signals are not getting down to supply. |
| May 26 1999 11:16:08:577AM | 990526009 | Robert Granetz | Shot 09 -- Test. |
| May 26 1999 11:16:19:403AM | 990526010 | Robert Granetz | Shot 10 -- Test. |
| May 26 1999 12:01:17:467PM | 990526011 | Robert Granetz | Shot 11 -- Test. |
| May 26 1999 12:02:20:827PM | 990526012 | Robert Granetz | Shot 12 -- Test. All fixed. |
| May 26 1999 12:14:52:857PM | 990526013 | Robert Granetz | Shot 13 -- Test. Final OH2 test, with power. Looks good, except the crowbar problem returned. |
| May 26 1999 12:35:19:950PM | 990526014 | Robert Granetz | Shot 14 -- Plasma. Good shot. Same as shot 05, except argon puffed, probe fired, and flapper opened at t=0.8 s. Right gap=1.25 cm. Br0 is still too negative. Next shot: increase right gap to 2.5 cm (reduce RCUR by 6 mm), and increase Br0 offset by another 0.5 mT (to +0.0035) |
| May 26 1999 12:49:25:077PM | 990526015 | Robert Granetz | Shot 15 -- Plasma. Good shot. Outer gap=2.0 cm, not 2.5 cm. Elongation rose to 1.7. Argon not puffed. Spencer reports that both F-side and B-bottom pressures were lower on this shot than the previous shot (when flaps are closed). Nice null. Next shot: increase right gap to 3.0 cm. Re-enable argon puff. |
| May 26 1999 01:08:17:433PM | 990526016 | Robert Granetz | Shot 16 -- Plasma. Disrupted at 0.53 s due to vertical instability; not unexpected. Outer gap reached 3.0 cm, elongation=1.75-1.8. Next shot: lower Zcur by 10 mm, and move argon puff to t=0.5 s. |
| May 26 1999 01:16:59:373PM | 990526017 | Robert Granetz | Shot 17 -- Fizzle. Br0 too high. Next shot: reduce Br0 by 1.5 mT (+0.0035 to +0.002 T). |
| May 26 1999 01:40:24:297PM | 990526018 | Robert Granetz | Shot 18 -- Plasma. Disrupted at t=0.55 s. Zcentroid did indeed drop by 1 cm. Elongation was only 1.7. Next shot: lower ZCUR another 1 cm, raise ZXU by 2 cm (S. Wolfe), and turn off argon. |
| May 26 1999 02:42:33:107PM | 990526019 | Robert Granetz | Shot 19 -- Plasma. Disrupted at t=0.55 s. Elongation was less than 1.7. EF4 was very close to the PLC limit. Next shot: same, except raise PLC limit from 8 to 8.5 kA |
| May 26 1999 02:52:07:107PM | 990526020 | Robert Granetz | Shot 20 -- Plasma. Disrupted at t=0.58 s, same stability problem. Next shot: ramp the gap. Start around t=0.4-0.6 at the RCUR from shot 15, and ramp to the gap on shot 20 at t=1.5 s. |
| May 26 1999 03:05:51:357PM | 990526021 | Robert Granetz | Shot 21 -- Plasma. Disrupted at t=0.36 s. I think it was a moly injection, not a VDE. Next shot: repeat, no changes. |
| May 26 1999 03:19:21:717PM | 990526022 | Robert Granetz | Shot 22 -- Fizzle. Br0 was too positive. Next shot: decrease Br0 offset by 1 mT, and start outer gap ramp at the same value as on shot 5 (and ramp down to the value on shot 20. |
| May 26 1999 03:40:24:217PM | 990526023 | Robert Granetz | Shot 23 -- Plasma. Better. Gap scanned from 1.1 to 3.0 cm. Disrupted at t=1.53 s, when the outer gap reached 3.0 cm, even though the elongation was low (because ZCUR was still down by 2 cm). Next shot: re-load shot 05. Also reduce Br0 by another 0.5 mT. Also reduce I_EF4 by 15 amps. |
| May 26 1999 03:51:16:433PM | 990526024 | Robert Granetz | Shot 24 -- Plasma. Good shot. Outer gap=1.4 cm. Next shot: decrease outer gap to 3 mm. Also reduce IC_EF4 by another 15 amps, and reduce Br0 by another 0.5 mT. |
| May 26 1999 04:04:19:780PM | 990526025 | Robert Granetz | Shot 25 -- Plasma. Good shot. Outer gap=0.5 cm. Next shot: argon puff at t=0.5 s. Also reduce IC_EF4 by another 15 amps, and reduce Br0 by another 0.5 mT. |
| May 26 1999 04:21:50:327PM | 990526026 | Robert Granetz | Shot 26 -- Plasma. Good shot. Outer gap=0.5 cm. (The nulls since shot 22 have looked really awful on the mflux plots, but they're still going. This shot may have hit something at 27 ms.) Next shot: reduce gap to 0 cm! |
| May 26 1999 04:46:52:700PM | 990526027 | Robert Granetz | Shot 27 -- Aborted (hung up in INIT). |
| May 26 1999 04:49:58:747PM | 990526027 | Robert Granetz | Shot 28 -- Dud. Lots of power supplies didn't fire. |
| May 26 1999 06:04:40:530PM | 990526029 | Robert Granetz | Shot 29 -- Plasma. Good shot. Marginally limited on outboard limiter for the entire flattop. No obvious problems with molydenum or Prad. Argon puffed at t=0.3 s. Null still looks awful. End of run. |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 07:50:57:390AM | Test | Ok | OH1,2 10KA Comm. test |
| 2 | 08:03:22:640AM | Test | Ok | EF4 Hybrid doubleswing test OK |
| 3 | 08:14:35:390AM | Plasma | Bad | No Shot Auto crowbar OH2 in Init |
| 4 | 08:29:30:077AM | Plasma | Ok | Fizzel /Auto Crowbar fire in OH2u switch |
| 5 | 08:44:55:607AM | Plasma | Ok | oh2 switch auto crobar/plasma |
| 6 | 09:19:52:607AM | Plasma | Bad | OH2 switchno close, no open no comm |
| 7 | 09:38:38:450AM | Test | Bad | OH PLC comm test plc control. no comm. |
| 8 | 10:12:31:107AM | Test | Bad | OH2 trigger test, no pulses at SCRS |
| 9 | 10:55:36:700AM | Test | Ok | OH2 Commutation test - no power |
| 10 | 11:14:44:687AM | Test | Ok | OH2 Commutation Test - no power |
| 11 | 11:21:28:297AM | Test | Ok | OH2 Comutation Test - No Power |
| 12 | 11:59:05:560AM | Test | Ok | OH2 trigger test |
| 13 | 12:09:49:123PM | Test | Ok | OH2 Commutation Test |
| 14 | 12:23:07:937PM | Test | Ok | no faults/plasma |
| 15 | 12:37:41:500PM | Plasma | Ok | no faults/plasma |
| 16 | 12:55:26:640PM | Plasma | Ok | disruption/OH1 self powered ckt. fired after disruption |
| 17 | 01:10:40:873PM | Plasma | Ok | no faults/fizzel |
| 18 | 01:24:11:090PM | Plasma | Ok | no faults |
| 19 | 02:24:05:390PM | Plasma | Ok | No faults |
| 20 | 02:42:32:093PM | Plasma | Ok | No Faults |
| 21 | 02:57:10:750PM | Plasma | Ok | no faults |
| 22 | 03:10:36:247PM | Plasma | Ok | No faults |
| 23 | 03:24:14:107PM | Plasma | Ok | No Faults |
| 24 | 03:41:42:357PM | Plasma | Ok | No Faults |
| 25 | 03:55:12:280PM | Plasma | Ok | No Faults |
| 26 | 04:14:12:857PM | Plasma | Ok | No Faults |
| 27 | 04:40:00:153PM | Test | Bad | |
| 28 | 04:47:09:107PM | Plasma | Bad | Not all supplies pulsed |
| 29 | 04:58:23:200PM | Plasma | Ok | No Faults |