| Miniproposals | ||||||||||
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| Operators | |
| Session leader(s): | Miklos Porkolab |
| Physics operator(s): | Robert Granetz,Jim Irby |
| Engineering operator(s): | Unknown |
| Engineering Operator Run Comment |
| MP#391 Alfvén Cascades with Current Rise ICRF Heating; SL:Porkolab/Snipe |
| Session Leader Plans |
| Physics Operators Plans |
| Session Leader Summaries |
| Entered: Jul 7 2004 03:49:04:240PM |
| Author: Miklos Porkolab |
| Session Summary for 1040406. ----------------------------------------------------------------------- MP 391 -- Alfvén Cascades with Current Rise ICRF Heating Session leader: M. Porkolab/J. Snipes Physics operator: R. Granetz ------------------------------------------------------------------------------- Run plan: 1. Establish good current ramp discharge and scan RF power to maximum power - get good probe data 2. Scan J antenna phase (3 good shots) 3. Scan B-field to move deposition to high (5.1 T) and low field side (5.7 T) (4 good shots) 4. Scan plasma elongation. 5. Scan current ramp rate. - It was a relatively successful day when most of the tasks were completed. This included optimizing power coupling in the ramp phase, with total RF power up to 5 MW, variation of the magnetic field at values of 4.8, 5.1, 5.4, 5.7 and 6.0T, and variation of the current ramp up to values between 0.70 MA to 1.0 MA. We carried out co and counter currend drive phasing with limited success near the end of the day. We have not carried out Task 4, plasma elongation scans. We have observed many Alfven wave cascade events on both PCI and magnetic loop probes. The data will be analyzed in the near future. The best shots were 13 and 26, with lots of cascades and grand cascades up to 400KHz, as well as TAE modes in the steady state phase, including H modes (with and without ELMS). In brief, moving the resonance to the high field side (lowering the magnetic field to 4.8T) eliminated the cascades, whereas moving the cyclotron minority resonance to the low field side (raising the magnetic field all the way to 6.0 T) maintained the cascades, and at least qualititively, moving the resonance slightly to the low field side (5.7T) resulted in the richest cascade spectrum, on both the PCI and magnetic loop probes. Phasing the J-port antenna to co or counter current drive did not have an obvious effect (at 5.7T) althoughthis will require a closer examination owing to the many trips in the early time frame when cascades were numerous. |
| Physics Operator Summaries |
| Entered: Jul 7 2004 04:36:49:787PM |
| Author: Jim Irby |
| Physics operator summary for run 1040406 (Tuesday): MP 391 -- Alfvén Cascades with Current Rise ICRF Heating Session leader: M. Porkolab/J. Snipes Physics operator: R. Granetz Summary: The tokamak ran very well today -- no problems with TF breakers. The run was on the difficult side, since changes to ne, Ip, Bt, and Prf had to be made in both segments 1 and 2, since the time range of interest for the Alfven cascades was t=0.10-0.18 s. We had some problems with early disruptions when Prf>=5 MW, particularly at lower densities. We also demonstrated that high-field side heating did not produce Alfven cascades as well as low-field side heating. Scorecard: 28 plasmas 2 fizzles 1 duds 1 tests or no-power shot cycles 0 aborted and/or screwed up by computer problems 0 beam-into-gas calibration shots with B-field(s) ---------- 32 total ------------------------------------------------------------------------------- Engineering setup for Thursday, 25 Mar 2004 MP 391 -- Alfvén Cascades with Current Rise ICRF Heating Session leader: M. Porkolab/J. Snipes Physics operator: R. Granetz ECDC overnight in D2 at 2e-4 Torr, stopping by 07:00. Run begins at 09:00 and ends at 17:00. Power Supplies as on 1030709012 A-coils should be enabled and configured as on shot 1040405015. Gas setup: fill B-Top with 6 psi D2 Hybrid enabled (PG4) fill B-side lower with 1 psi Ar Hybrid enabled (PG1) leave B-side upper as is Hybrid DISABLED (PG2) fill C-side with 30 psi D2 Hybrid enabled (PG3) Enable the following gate valves, assuming no vacuum problems: ECE, VUV, DNB Disable the following: NINJA Necessary diagnostics: Mirnov coils, PCI, A-side magnetic probe ------------------------------------------------------------------------------- RF setup: #1-#4 in run-on by 8:30 am ------------------------------------------------------------------------------- Run plan: 1. Establish good current ramp discharge and scan RF power to maximum power - get good probe data 2. Scan J antenna phase (3 good shots) 3. Scan B-field to move deposition to high (5.1 T) and low field side (5.7 T) (4 good shots) 4. Scan plasma elongation. 5. Scan current ramp rate. ------------------------------------------------------------------------------- ECDC was done overnight, but no bake. Hybrid coldstart done by the engineering group; no errors found Loaded PCS segments 2,3,4 from shot 1030709012 PCS segment 1 from shot 1040405003 Changed A-coil programming in segment 2 to 2000 A (from 4000 A) ------------------------------------------------------------------------------- Shot 01 -- Plasma. Good full-length shot, but no RF. 0.8 MA, 5.4 T. Some moly injections. Several systems didn't init (RF), and several analysis programs didn't run. Next shot: repeat, try to get the RF going this time. Delay while Josh is sorting out the computer problems. Shot 02 -- Plasma. Good shot. Got some RF this time, mostly from E, a little from D, none from J. No Alfven modes. Next shot: more RF power Shot 03 -- Plasma. Good shot. Same RF performance, i.e. nothing from J. Not much in the way of Alfven modes. Next shot: get J-port antenna going Shot 04 -- Plasma. Good shot. Got some power from J-port this time. Slightly better Alfven signals. Next shot: keep working on the RF Shot 05 -- Plasma. Good shot. D and E are pretty good, J is still having trouble. Prf=2 MW. Alfven modes are evident, but not the good cascades. Next shot: keep working on the RF Shot 06 -- Plasma. Good shot. Good RF. Prf=3.5-3.8 MW. Some nice Alfven cascades on both the magnetics and the PCI. Next shot: still more RF power Shot 07 -- Plasma. Good shot, but J port didn't perform as well, so the RF power was less than the previous shot. Clearly the higher power gives better Alfven cascades. Next shot: "more power Scottie" (quote from Joe Snipes) Shot 08 -- No-power shot. PF breaker opened during check, so opened all the breakers and ran through the shot cycle. Shot 09 -- Plasma. Good shot. Prf=4.2 MW. Good Alfven cascades. Next shot: try going for very low density later in the shot, to see if we can help Ian fill in some locked mode regimes in piggyback mode. Shot 10 -- Plasma. Good shot. Prf=4.2 MW. Good Alfven cascades. Flattop density got down to nl=5.e19 m-2, which is not low enough for Ian's request. Next shot: retune J port to earlier time. Shot 11 -- Plasma. Good shot. Prf briefly peaks at 5 MW, but then drops back to 2.2 MW. Good cascades on PCI. Next shot: reduce the pre-programmed gas puff a little during the first 100 ms of the discharge. Shot 12 -- Plasma. Good shot. Prf briefly peaks at 5 MW. Nice Alfven cascades at t=0.16 s. Not sure the initial density is really any lower. From t=1.0-1.5 s, nebar= 6.5e19 m-2 and A-coil current = 1500 A. Next shot: repeat early shot, but reduce A-coil current to 1000 amps for Ian's locked mode point (even though the density is still a little high). Shot 13 -- Plasma. Good shot. Really nice RF, 5.1 MW by t=0.125 s, and staying on until t=0.5 s. One grand cascade at t=0.16 s. A-coil current=1.0 kA from t=1.0-1.5 s, but the density did not get as low as the previous shots, presumably because the total RF deposited energy was a lot higher on this shot. No sign of a locked mode. Next shot: for RF tweaking Shot 14 -- Plasma. Good shot. Another beauty from the RF...a steady 5.1 MW again. Grand cascade at t=0.16 s (when qmin=2 ?) Next shot: set plasma current up to 1.0 MA for the entire shot, and set A-coil current to 1.0 kA starting at t=0.5-0.6 s. Shot 15 -- Plasma. Disrupted at t=0.57 s. I_halo_L=140 kA. Got an stress warning on EF2U. Next shot: Increase Ip to 1.1 MA. Also delay the drop in the A-coil current slightly to move it away from the RF turn off time. Shot 16 -- Plasma. Disrupted very early. I think it's radiating too much power. Still got some Alfven cascades though. Next shot: drop Ip to 0.6 MA for early part of shot, then ramp it back up to 1.0 MA for late flattop (for Ian). Shot 17 -- Plasma. Another early disruption. 2pi_foil shows 6 MW radiated. Next shot: cut RF power in half to see if the disruption goes away. Shot 18 -- Plasma. Disrupted at t=0.81 s, but it wasn't a locked mode. Prf=2.7 MW, as requested. Nice cascades. Next shot: reduce Ip to 0.5 MA, and keep it constant throughout the shot. Keep A-coil current at 1500 A throughout the shot also. (i.e. abandon the locked mode piggybacking) Shot 19 -- Fizzle. Not obvious why, although there are some small differences in the magnetic signals. Next shot: no changes. Shot 20 -- Fizzle again. Next shot: reduce Br0 offset by 0.5 mT Shot 21 -- Plasma. Good shot. Early Ip overshoots the requested 0.5 MA. Prf=2.7 MW. Next shot: drop Bt to 5.1 T (constant in seg 1 and 2) and set Ip at 0.8 MA (by reloading Ip from shot 01) Shot 22 -- Plasma. Very early disruption, just as the RF power reaches 5.1 MW. Next shot: restore PG3 gas in seg 1 to that of shot 01. Also increase nl_04 after t=0.5 s back to 0.7e20 m-2 Shot 23 -- Plasma. Good shot. 0.8 MA, 5.17 T. Prf=5-4.5 MW. Cascades Next shot: reduce Bt to 4.8 T (constant in segs 1 and 2, so the breakdown may be affected) Shot 24 -- Dud. Next shot: increase pre-fill by 2 ms and subtract 10 amps from IC_EF4. Shot 25 -- Plasma. Good shot. 0.8 MA, 4.8 T. Prf=5.1 MW. No cascades. Pretty convincing that high-field side heating doesn't produce Alfven cascades. Next shot: raise Bt to 5.7 T Shot 26 -- Plasma. Good shot. 0.8 MA, 5.7 T. Prf=5 MW. Lots and lots of good Alfven cascades. Pretty clear that low-field side heating is better for producing Alfven cascades. Next shot: increase Bt to 6.0 T Shot 27 -- Plasma. Disrupted at t=0.33 s. Prf=2-5 MW. Still got Alfven modes. Next shot: decrease Bt to 5.7 T (by reloading shot 26) Jim Irby will substitute as physics operator for me for the remainder of the run. Shot 28 -- Plasma. Good shot. 0.8 MA, 5.7 T. Prf=5 MW. Good Alfven cascades. No TCI density. Next shot: same plasma; change RF phasing. Shot 29 -- Plasma. Good shot. Prf=2.5-5 MW. Got great Alfven cascades on both the magnetics and the PCI. Next shot: no changes Shot 30 -- Plasma. Good shot. Prf=4-5 MW. More grand cascades. Next shot: no changes Shot 31 -- Plasma. Good shot. Prf=4+ MW. Lower amplitude Alfven cascades than preceding two shots. Next shot: no changes Shot 32 -- Plasma. Good shot. Prf=2-5 MW, lots of faulting. Still lots of good Alfven cascades though. End of run. |
| Session Leader Comments | |||
| Apr 6 2004 09:21:58:810AM | 1040406001 | Miklos Porkolab | Good plasma shot. No RF. |
| Apr 6 2004 09:56:28:520AM | 1040406002 | Miklos Porkolab | Good plasma shot. RF not steady, keeps dropping out. Max power 2 MW, average power is 1.3 MW. |
| Apr 6 2004 10:15:13:220AM | 1040406003 | Miklos Porkolab | Good plasma , RF average power is 1.3 MW, peak power at 2.5 MW, drops out often. |
| Apr 6 2004 10:40:09:290AM | 1040406004 | Miklos Porkolab | Good plasma shot, RF varies between 2-3 MW during ramp, drops to 1.3 MW after 0.18 sec, then recovers , etc. Had large ELMS between 0.2-0.22 sec. During this time the RF power dropped from 3.2 MW to 1.2 MW and Te pedestal drops from 600 eV to 200 eV while the pedestal density drops from 1.5e(20) to 0.5e(20). |
| Apr 6 2004 10:55:25:110AM | 1040406005 | Miklos Porkolab | RF power is only 2 MW, getting into ELM free H mode at 0.18 sec. Some evidence of cascades. Te=4 keV at 0.2 sec.Some ELM activity at 0.17-0.18 sec. However, not as large as in the previous shot. |
| Apr 6 2004 11:06:14:250AM | 1040406006 | Miklos Porkolab | RF power is 3.5 MW and steady during ramp, getting into ELM free H mode at 0.166sec (still limited). Evidence of cascades. Te=4keV at 0.16 sec. Some ELM activity at 0.16 sec. Te_pedestal at 400-500 eV. Grand cascades at 0.12 sec, and a grand cascade at 0.15 sec. (Are these at crossing q(min)=3 and q(min)=2 ?). |
| Apr 6 2004 11:14:19:467AM | 1040406007 | Miklos Porkolab | Rf power not steady, drops in and out between 2.0 and 4.0 MW. Not as good as previous shot. PCI quality not good enough, will go into cell after next shot to sheck for laser power. |
| Apr 6 2004 11:18:27:863AM | 1040406008 | Miklos Porkolab | No plasma shot. |
| Apr 6 2004 12:02:23:557PM | 1040406009 | Miklos Porkolab | Good shot, get up to 4.3 MW by 0.16 second and get into H mode right after that time (and lasted until 0.3 sec). Some cascade at 0.12 sec. Current ramping until 0.2 sec, to 0.9 MA. Neutron rate up to 3.0e(13) by 0.3 sec. Density fairly high at 0.2 sec. |
| Apr 6 2004 12:11:28:493PM | 1040406010 | Miklos Porkolab | RF not very good, drop in and out between 2 and 4 MW. One good cascade at 0.115 second while Prf=2.0 MW, peak density 1.2e(20), nl=0.7e(20). |
| Apr 6 2004 12:22:02:087PM | 1040406011 | Miklos Porkolab | Good cascade. RF power up to 4 MW from 0.12-0.13 sec and 0.15 to 0.17 sec. See good cascades, especially at 0.15-0.16 sec (looks like a grand cascade, perhaps at q_min=2 ?). Density is failrly low. Will lower pre-puff on next shot to lower density even more. |
| Apr 6 2004 12:36:03:420PM | 1040406012 | Miklos Porkolab | Good cascade. RF power up to 4.8 MW from 0.12-0.17 sec and lower later See good cascades, especially at 0.15-0.16 sec (looks like a grand cascade, perhaps at q_min=2 ?). Lowered pre-puff to lower density even more. Elms and H mode occurs at 0.164 sec, right after last ELM. Is there a correlation ? |
| Apr 6 2004 12:48:54:347PM | 1040406013 | Miklos Porkolab | Good cascade. RF power up to 5 MW from 0.14-0.17 sec and holding steady. 3 cascade modes at 0.15-0.16 sec (looks like a grand cascade, perhaps at q_min=2 ?). Lowered pre-puff to lower density even more. See 3 modes on both PCI and magnetic loops. |
| Apr 6 2004 01:27:32:217PM | 1040406014 | Miklos Porkolab | Similar to shot 13. RF power up to 5 MW from 0.14-0.17 sec and holding steady. 2 cascade modes at 0.15-0.16 sec (looks like a grand cascade, perhaps at q_min=2 ?). Also, there are lots of high frequency modes, some at harmonic (700kHz) some at 1 MHz, etc. Deserves further study. Some activity at 0.12 sec. Minority concentration good, from 0.03 to 0.05. |
| Apr 6 2004 01:25:17:540PM | 1040406015 | Miklos Porkolab | Similar to shot 14. RF power up to 5 MW from 0.12 sec and holding steady. 2 cascade modes at 0.15-0.16 sec (looks like a grand cascade, perhaps at q_min=2 ?). Also, there is a more pronounced double mode cascade at 0.11-0.12 sec, although power is only 3 MW. Current was increased to 1.0 MA at 0.16 sec. On Earlier shots we called for 0.8 MA at 0.16 sec. Got disruption after 0.5 sec. |
| Apr 6 2004 01:36:39:133PM | 1040406016 | Miklos Porkolab | Requested current to 1.1 MA at t=0.20 sec but only got to 0.8 MW. Got disruption at 0.2 sec. Alfven cascades similar to the previous shot. 2 modes at 0.15 sec (grand) and 2 individual cascades at 0.12 sec. Lots of radiated power early on. Will lower the current ramp on the next shot. |
| Apr 6 2004 01:46:26:457PM | 1040406017 | Miklos Porkolab | Requested current to 0.6 MA at t=0.16 sec. Got disruption at 0.25 sec. RF power is up to 5 MW after 0.12 sec, rising steadily from 2.5 MW at 0.11 sec. Reasonable cascade of 2 modes at 0.15 sec, cascades missing at earlier time, 0.12 sec. Hence, higher current is best for early cascades, but some long pulse, higher frequency TAEs stay longer. For the record, q_95=5.2-5.0. Will repeat shot at lower power to clean it up. |
| Apr 6 2004 02:00:08:157PM | 1040406018 | Miklos Porkolab | Requested current to 0.6 MA at t=0.16 sec. Cut RF power into half to clean up machine. Had excellent cascades on the PCI as well as the magnetics. Best PCI cascades yet. q_95=5.2. Ip=0.7MA at t=0.15 sec. Will lower current further on next shot. |
| Apr 6 2004 02:27:56:750PM | 1040406019 | Miklos Porkolab | Requested current to 0.5 MA at t=0.16 sec. Cut RF power into half to clean up machine. Fizzle, no plasma. |
| Apr 6 2004 02:28:47:453PM | 1040406020 | Miklos Porkolab | Requested current to 0.5 MA at t=0.16 sec. Cut RF power into half to clean up machine. Fizzle, no plasma. |
| Apr 6 2004 02:40:31:280PM | 1040406021 | Miklos Porkolab | Requested current to 0.5 MA at t=0.16 sec. However, in reality got Ip=0.7 MA at 0.15 sec, and q=5.2. Prf=2.7 MW, with a few drop-outs after 0.25 sec. Good plasma , recovered from disruption. Some minimal cascade at t=0.1 sec, not very impressive. Will lower B field on next shot to 5.1 T. |
| Apr 6 2004 02:55:09:953PM | 1040406022 | Miklos Porkolab | First shot of B-field scan. Lowered B=5.1 T. Set Ip=0.8 MA. Plasma disrupted at 0.14 sec. Do not see any cascades uup to this time. |
| Apr 6 2004 03:04:08:650PM | 1040406023 | Miklos Porkolab | Repeat shot of B-field scan. Lowered B=5.1 T. Set Ip=0.8 MA. (it si 0.75 at t=0.15 sec) q_95=4.5. Increased pre-puff to higher level. Got good plasma shot back. Prf=5.0 MW at t=0.11-0.122 sec, then drops back to 2.5 MW until 0.137 sec, then recoveres to 5.0 MW by 0.15 sec and then stays steady until 0.5 sec. Got one cascade only at 0.5 second. |
| Apr 6 2004 03:13:52:630PM | 1040406024 | Miklos Porkolab | Repeat shot of B-field scan. Lowered B=4.8T. Dud. Will repeat. |
| Apr 6 2004 03:36:52:813PM | 1040406025 | Miklos Porkolab | Repeat shot of B-field scan. Still at B=4.8T. Good shot. High Prf=5 MW at 0.15sec. No cascades. Completed trend. Will increase B to 5.7 T. |
| Apr 6 2004 03:57:53:527PM | 1040406026 | Miklos Porkolab | Repeat shot of B-field scan, increase B to B=5.7T. Good shot. Prf=5 MW after 0.15sec (2.5 to 4.0 before). Lots of cascades between 0.1 - 0.15 sec. Also, large ELMS during H mode at t=0.22-0.24 sec. |
| Apr 6 2004 04:04:41:753PM | 1040406027 | Miklos Porkolab | Repeat shot of B-field scan, increase B to B=5.9T. Not very good shot. Prf = 2.2-4.2 MW after 0.10sec. Only a few cascades between 0.1 - 0.15 sec. Current ramping to 0.8 MA, typical q=5.0 during Ip ramp phase. |
| Apr 6 2004 04:21:17:193PM | 1040406028 | Miklos Porkolab | Repeat shot of B-field scan, lower B to B=5.7T. Shot ok, not quite as good as earlier at the same field (shot 26). Some cascades between 0.1 - 0.15 sec. Current ramping to 0.8 MA, typical q=5.0 during Ip ramp phase. |
| Apr 6 2004 04:31:25:160PM | 1040406029 | Miklos Porkolab | B=5.7T, current drive phasing for J port. Everything else remains the same as previous shot. Got good cascade spectrum on both magnetic loops and PCI. Got somewhat different spectrum on PCI between shots 28 (heating phase) and shot 29 (current drive phasing), at least on the PCI |
| Apr 6 2004 04:41:37:640PM | 1040406030 | Miklos Porkolab | B=5.7T, current drive phasing for J port, repeat for better RF pulse. Everything else remains the same as previous shot. Co-current drive phasing. Unfortunately, J port antenna not really on much of the time until after 0.15 sec and by then cascades are over. Cascades present due to E and D port, mostly. |
| Apr 6 2004 04:54:00:390PM | 1040406031 | Miklos Porkolab | B=5.7T, co-current drive phasing for J port, repeat for better RF pulse. Everything else remains the same as previous shot. Co-current drive phasing. Unfortunately, J port antenna not really on much of the time until after 0.15 sec and by then cascades are over. Cascades present due to E and D port, mostly. Perhaps some "microscopic" examination might reveal some dependence. |
| Physics Operator Comments | |||
| Apr 5 2004 05:24:31:270PM | Robert Granetz | Engineering setup for Thursday, 25 Mar 2004 MP 391 -- Alfvén Cascades with Current Rise ICRF Heating Session leader: M. Porkolab/J. Snipes Physics operator: R. Granetz ECDC overnight in D2 at 2e-4 Torr, stopping by 07:00. Run begins at 09:00 and ends at 17:00. Power Supplies as on 1030709012 A-coils should be enabled and configured as on shot 1040405015. Gas setup: fill B-Top with 6 psi D2 Hybrid enabled (PG4) fill B-side lower with 1 psi Ar Hybrid enabled (PG1) leave B-side upper as is Hybrid DISABLED (PG2) fill C-side with 30 psi D2 Hybrid enabled (PG3) Enable the following gate valves, assuming no vacuum problems: ECE, VUV, DNB Disable the following: NINJA Necessary diagnostics: Mirnov coils, PCI, A-side magnetic probe ------------------------------------------------------------------------------- RF setup: #1-#4 in run-on by 8:30 am ------------------------------------------------------------------------------- Run plan: 1. Establish good current ramp discharge and scan RF power to maximum power - get good probe data 2. Scan J antenna phase (3 good shots) 3. Scan B-field to move deposition to high (5.1 T) and low field side (5.7 T) (4 good shots) 4. Scan plasma elongation. 5. Scan current ramp rate. | |
| Apr 6 2004 08:18:11:103AM | Robert Granetz | ECDC was done overnight, but no bake. Hybrid coldstart done by the engineering group; no errors found Loaded PCS segments 2,3,4 from shot 1030709012 PCS segment 1 from shot 1040405003 Changed A-coil programming in segment 2 to 2000 A (from 4000 A) | |
| Apr 6 2004 09:32:28:730AM | 1040406001 | Robert Granetz | Shot 01 -- Plasma. Good full-length shot, but no RF. 0.8 MA, 5.4 T. Some moly injections. Several systems didn't init (RF), and several analysis programs didn't run. Next shot: repeat, try to get the RF going this time. Delay while Josh is sorting out the computer problems. |
| Apr 6 2004 09:52:31:250AM | 1040406002 | Robert Granetz | Shot 02 -- Plasma. Good shot. Got some RF this time, mostly from E, a little from D, none from J. No Alfven modes. Next shot: more RF power |
| Apr 6 2004 10:09:06:990AM | 1040406003 | Robert Granetz | Shot 03 -- Plasma. Good shot. Same RF performance, i.e. nothing from J. Not much in the way of Alfven modes. Next shot: get J-port antenna going |
| Apr 6 2004 10:35:33:877AM | 1040406004 | Robert Granetz | Shot 04 -- Plasma. Good shot. Got some power from J-port this time. Slightly better Alfven signals. Next shot: keep working on the RF |
| Apr 6 2004 10:38:55:227AM | 1040406005 | Robert Granetz | Shot 05 -- Plasma. Good shot. D and E are pretty good, J is still having trouble. Prf=2 MW. Alfven modes are evident, but not the good cascades. Next shot: keep working on the RF |
| Apr 6 2004 10:52:11:213AM | 1040406006 | Robert Granetz | Shot 06 -- Plasma. Good shot. Good RF. Prf=3.5-3.8 MW. Some nice Alfven cascades on both the magnetics and the PCI. Next shot: still more RF power |
| Apr 6 2004 11:10:31:430AM | 1040406007 | Robert Granetz | Shot 07 -- Plasma. Good shot, but J port didn't perform as well, so the RF power was less than the previous shot. Clearly the higher power gives better Alfven cascades. Next shot: "more power Scottie" (quote from Joe Snipes) |
| Apr 6 2004 11:19:01:147AM | 1040406008 | Robert Granetz | Shot 08 -- No-power shot. PF breaker opened during check, so opened all the breakers and ran through the shot cycle. |
| Apr 6 2004 11:47:54:330AM | 1040406009 | Robert Granetz | Shot 09 -- Plasma. Good shot. Prf=4.2 MW. Good Alfven cascades. Next shot: try going for very low density later in the shot, to see if we can help Ian fill in some locked mode regimes in piggyback mode. |
| Apr 6 2004 12:02:48:700PM | 1040406010 | Robert Granetz | Shot 10 -- Plasma. Good shot. Prf=4.2 MW. Good Alfven cascades. Flattop density got down to nl=5.e19 m-2, which is not low enough for Ian's request. Next shot: retune J port to earlier time. |
| Apr 6 2004 12:17:06:533PM | 1040406011 | Robert Granetz | Shot 11 -- Plasma. Good shot. Prf briefly peaks at 5 MW, but then drops back to 2.2 MW. Good cascades on PCI. Next shot: reduce the pre-programmed gas puff a little during the first 100 ms of the discharge. |
| Apr 6 2004 12:32:44:370PM | 1040406012 | Robert Granetz | Shot 12 -- Plasma. Good shot. Prf briefly peaks at 5 MW. Nice Alfven cascades at t=0.16 s. Not sure the initial density is really any lower. From t=1.0-1.5 s, nebar= 6.5e19 m-2 and A-coil current = 1500 A. Next shot: repeat early shot, but reduce A-coil current to 1000 amps for Ian's locked mode point (even though the density is still a little high). |
| Apr 6 2004 12:46:36:093PM | 1040406013 | Robert Granetz | Shot 13 -- Plasma. Good shot. Really nice RF, 5.1 MW by t=0.125 s, and staying on until t=0.5 s. One grand cascade at t=0.16 s. A-coil current=1.0 kA from t=1.0-1.5 s, but the density did not get as low as the previous shots, presumably because the total RF deposited energy was a lot higher on this shot. No sign of a locked mode. Next shot: for RF tweaking |
| Apr 6 2004 01:01:09:833PM | 1040406014 | Robert Granetz | Shot 14 -- Plasma. Good shot. Another beauty from the RF...a steady 5.1 MW again. Grand cascade at t=0.16 s (when qmin=2 ?) Next shot: set plasma current up to 1.0 MA for the entire shot, and set A-coil current to 1.0 kA starting at t=0.5-0.6 s. |
| Apr 6 2004 01:16:49:313PM | 1040406015 | Robert Granetz | Shot 15 -- Plasma. Disrupted at t=0.57 s. I_halo_L=140 kA. Got an stress warning on EF2U. Next shot: Increase Ip to 1.1 MA. Also delay the drop in the A-coil current slightly to move it away from the RF turn off time. |
| Apr 6 2004 01:28:13:390PM | 1040406016 | Robert Granetz | Shot 16 -- Plasma. Disrupted very early. I think it's radiating too much power. Still got some Alfven cascades though. Next shot: drop Ip to 0.6 MA for early part of shot, then ramp it back up to 1.0 MA for late flattop (for Ian). |
| Apr 6 2004 01:40:35:827PM | 1040406017 | Robert Granetz | Shot 17 -- Plasma. Another early disruption. 2pi_foil shows 6 MW radiated. Next shot: cut RF power in half to see if the disruption goes away. |
| Apr 6 2004 01:59:23:810PM | 1040406018 | Robert Granetz | Shot 18 -- Plasma. Disrupted at t=0.81 s, but it wasn't a locked mode. Prf=2.7 MW, as requested. Nice cascades. Next shot: reduce Ip to 0.5 MA, and keep it constant throughout the shot. Keep A-coil current at 1500 A throughout the shot also. (i.e. abandon the locked mode piggybacking) |
| Apr 6 2004 02:10:03:747PM | 1040406019 | Robert Granetz | Shot 19 -- Fizzle. Not obvious why, although there are some small differences in the magnetic signals. Next shot: no changes. |
| Apr 6 2004 02:39:51:373PM | 1040406020 | Robert Granetz | Shot 20 -- Fizzle again. Next shot: reduce Br0 offset by 0.5 mT |
| Apr 6 2004 02:39:25:983PM | 1040406021 | Robert Granetz | Shot 21 -- Plasma. Good shot. Early Ip overshoots the requested 0.5 MA. Prf=2.7 MW. Next shot: drop Bt to 5.1 T (constant in seg 1 and 2) and set Ip at 0.8 MA (by reloading Ip from shot 01) |
| Apr 6 2004 02:54:14:500PM | 1040406022 | Robert Granetz | Shot 22 -- Plasma. Very early disruption, just as the RF power reaches 5.1 MW. Next shot: restore PG3 gas in seg 1 to that of shot 01. Also increase nl_04 after t=0.5 s back to 0.7e20 m-2 |
| Apr 6 2004 03:07:19:327PM | 1040406023 | Robert Granetz | Shot 23 -- Plasma. Good shot. 0.8 MA, 5.17 T. Prf=5-4.5 MW. Cascades Next shot: reduce Bt to 4.8 T (constant in segs 1 and 2, so the breakdown may be affected) |
| Apr 6 2004 03:16:01:087PM | 1040406024 | Robert Granetz | Shot 24 -- Dud. Next shot: increase pre-fill by 2 ms and subtract 10 amps from IC_EF4. |
| Apr 6 2004 03:31:23:870PM | 1040406025 | Robert Granetz | Shot 25 -- Plasma. Good shot. 0.8 MA, 4.8 T. Prf=5.1 MW. No cascades. Pretty convincing that high-field side heating doesn't produce Alfven cascades. Next shot: raise Bt to 5.7 T |
| Apr 6 2004 03:46:22:060PM | 1040406026 | Robert Granetz | Shot 26 -- Plasma. Good shot. 0.8 MA, 5.7 T. Prf=5 MW. Lots and lots of good Alfven cascades. Pretty clear that low-field side heating is better for producing Alfven cascades. Next shot: increase Bt to 6.0 T |
| Apr 6 2004 03:56:16:710PM | 1040406027 | Robert Granetz | Shot 27 -- Plasma. Disrupted at t=0.33 s. Prf=2-5 MW. Still got Alfven modes. Next shot: decrease Bt to 5.7 T (by reloading shot 26) |
| Apr 6 2004 03:56:47:197PM | 1040406028 | Robert Granetz | Jim Irby will substitute as physics operator for me for the remainder of the run. |
| Apr 6 2004 04:20:02:100PM | 1040406028 | Jim Irby | Taking over last hour for Bob Plasma Lost all TCI data --- I was running test routine when we went into INIT |
| Apr 6 2004 04:25:25:933PM | 1040406029 | Jim Irby | No PCS changes RF phase change Plasma --- TCI is back |
| Apr 6 2004 04:45:36:767PM | 1040406030 | Jim Irby | PCS repeat Plasma |
| Apr 6 2004 04:50:26:620PM | 1040406031 | Jim Irby | PCS repeat Plasma |
| Apr 6 2004 05:05:51:167PM | 1040406032 | Jim Irby | PCS repeat Good shot |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 09:11:07:277AM | Plasma | Ok | |
| 2 | 09:39:29:650AM | Plasma | Ok | |
| 3 | 09:53:27:937AM | Plasma | Ok | |
| 4 | 10:09:41:510AM | Plasma | Ok | |
| 5 | 10:26:37:940AM | Plasma | Ok | |
| 6 | 10:43:05:200AM | Plasma | Ok | |
| 7 | 10:57:22:830AM | Plasma | Ok | |
| 8 | 11:13:12:887AM | Plasma | Bad | EF1 Instrumentation fault during check |
| 9 | 11:35:17:750AM | Plasma | Ok | |
| 10 | 11:48:54:723AM | Plasma | Ok | |
| 11 | 12:06:30:547PM | Plasma | Ok | |
| 12 | 12:19:12:037PM | Plasma | Ok | |
| 13 | 12:34:02:590PM | Plasma | Ok | |
| 14 | 12:47:38:190PM | Plasma | Ok | |
| 15 | 01:04:27:207PM | Plasma | Ok | |
| 16 | 01:18:36:080PM | Plasma | Ok | |
| 17 | 01:31:57:020PM | Plasma | Ok | |
| 18 | 01:45:01:910PM | Plasma | Ok | |
| 19 | 02:01:23:063PM | Plasma | Ok | |
| 20 | 02:14:48:890PM | Plasma | Ok | |
| 21 | 02:27:37:377PM | Plasma | Ok | |
| 22 | 02:41:05:733PM | Plasma | Ok | |
| 23 | 02:54:03:890PM | Plasma | Ok | |
| 24 | 03:07:22:937PM | Plasma | Ok | |
| 25 | 03:19:44:577PM | Plasma | Ok | |
| 26 | 03:32:28:497PM | Plasma | Ok | |
| 27 | 03:47:44:530PM | Plasma | Ok | |
| 28 | 04:02:17:217PM | Plasma | Ok | |
| 29 | 04:16:56:767PM | Plasma | Ok | |
| 30 | 04:31:19:737PM | Plasma | Ok | |
| 31 | 04:45:17:237PM | Plasma | Ok | |
| 32 | 05:00:01:237PM | Plasma | Ok | |