| Miniproposals | ||||||||||
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| Operators | |
| Session leader(s): | Ron Parker,Brian Labombard |
| Physics operator(s): | Robert Granetz |
| Engineering operator(s): | Unknown |
| Engineering Operator Run Comment |
| MP 307: High bootstrap-fraction regimes SL: R. Parker PO: R. Granetz EO: |
| Session Leader Plans |
| Physics Operators Plans |
| Session Leader Summaries |
| Entered: Jul 7 2004 03:49:04:147PM |
| Author: Ron Parker |
| ;; This buffer is for notes you don't want to save, and for Lisp evaluation. ;; If you want to create a file, visit that file with C-x C-f, ;; then enter the text in that file's own buffer. Run Summary The purpose of the run was to try to optimize bootstrap current in ITB discharges. The plan was to begin with one of the more successful ITB discharges obtained on shot 1040309029 that had not only good density peaking, but also a central temperature increase with application of central ICRF power. This was to be a continuation of MP 307, which was not successful in a previous run because of strong impurity radiation and the lack of central ICRF power. Unfortunately we were not able to produce relatively stable ITB's. ITB's were formed on most shots but terminated before they could be stablized by central power. unlike the earlier attempt at MP 309, the problem was not obviously due to radiative collapse of the center. But no indication of central heating due to on axis power was found. After 23 shots, we decided to not pursue this MP further and switched Session Leaders to B. Labombard. On reflection, it is dubious that ITB's are optimal for high bootstrap fractions because they are rather narrow except possibly at low q. But at low q (high current), the poloidal field is strong and the bootstrap fraction tends to be low.Thus, although the strong density gradient is attractive, the combination of strong poloidal field and localization of grad n near the center is working against a high bootstrap fraction. What was special about shot 1040309029 was the central temperature rise,as this also promotes high bootstrap fraction.But this could not be reproduced in this run. |
| Entered: Jul 7 2004 03:49:04:163PM |
| Author: Brian Labombard |
| Run Summary for 1040325b This is a summary for shots starting at 24, MP#384 Physics Operator: R, Granetz Session Leader: B. LaBombard ______________________________________________________________________________ MP#384 - Experiments on Plasma Flows and the L-H Threshold: low density discharges, limited versus diverted topologies and the role of neutrals Purpose: Explore relationships between edge plasma flows, magnetic topologies, and the L-H power threshold. This is the second run devoted to this MP, focusing on lower-limited and lower x-point topologies. Shot Plan: All shots are 0.8MA, 5.4 tesla discharges. C. Effect of inner divertor nose recycling on SOL/core momentum coupling - and - D. L-H Thresholds in Lower Limited versus Lower Diverted Discharges Set probe scan times to 0.7 and 0.9 seconds. Program RF power ramp of 0.5 to 1.5 MW over time interval 0.95 to 1.5 sec. Shot A - Reload from 1040213028 which was a SNL discharge with NORMAL inner divertor nose gap. Find L-H threshold power at NL04=0.6e20 Record flows. Shot B - Reload from 1040213027 - a SNL discharge with SMALL inner divertor nose gap. Find L-H threshold power at NL04=0.6e20 Record flows. Shot C - Program lower x-point position to LIMIT discharge on inner divertor nose Find L-H threshold power at NL04=0.6e20 Record flows. Cycle through shots A, B, C until a good matched set is achieved. "good match" = clean RF ramp with same NL04 at L-H transition time. Repeat this for NL04=0.9e20 Repeat this for NL04=1.2e20 (or go directly to part E) E. (Extra credit) Effect of Inner Gap Repeat Shot A at NL04=0.9e20 with successively reduced inner gaps: 4, 2, 0 mm Map change in L-H threshold powers Record flows => do not scan ISP! ______________________________________________________________________________ Result: A very good start on the balance of this MP. We managed to setup Shots A,B,C as outlined in the run plan and to begin to optimize the probe targeting. It is clear from the shots today that the L-H threshold does not care whether the plasma has a lower x-point or is limited on the inner divertor nose. With further optimization, we should be able to get good flow info, up to the separatrix. Martin noticed some interesting ELM behavior on the LIMITED shots, 31, 32. ______________________________________________________________________________ Detailed Shot log: 24 - SNL, normal inner divertor nose gap. ASP(+10), FSP(-5), ISP => L-H at 1.07 s, 0.89 MW, NL04=0.89 25 - SNL, normal inner divertor nose gap. ASP(+10), FSP(-5), ISP => L-H at 1.12 s, 1.0 MW, NL04=0.8 26 - SNL, normal inner divertor nose gap. ASP(+10), FSP(-5), ISP target changed. ASP FSP too far out. => L-H at 1.04 s, 0.8 MW, NL04=0.57 27 - SNL, normal inner divertor nose gap. ASP(+14), FSP(1), ISP target changed back on FSP! => No H-mode 28 - SNL, NORMAL inner divertor nose gap. ASP(+14), FSP(-4), ISP => L-H at 1.27 s, 1.3 MW, NL04=0.7 29- SNL, SMALL inner divertor nose gap. ASP(+10), FSP(+8), ISP => L-H at 1.19s, 1.0 MW, NL04=0.72 30- SNL, SMALLer inner divertor nose gap. ASP(+10), FSP(+8)(should have been +12), ISP => L-H at 1.2s, 1.18 MW, NL04=0.64 31- SNL, LIMITED on inner divertor nose ASP(+12), FSP(+12), ISP => L-H at 1.11s, 1.0 MW, NL04=0.63 32- SNL, LIMITED on inner divertor nose ASP(+17) -too deep, FSP(+22) -too deep, ISP => L-H at 1.19s, 1.15 MW, NL04=0.67 |
| Physics Operator Summaries |
| Entered: Jul 7 2004 04:36:49:660PM |
| Author: Robert Granetz |
| Physics operator summary for run 1040325 (Thursday): MP 307 -- High bootstrap-fraction regimes MP 384 -- Plasma flows and L-H threshold in different configurations Session leader: R. Parker (MP 307) / B. Labombard (MP 384) Physics operator: R. Granetz Summary: All tokamak systems ran very reliably today. We had no fizzles, and only one shot that had a computer problem, and one shot that had the breakers pull out early. Two MP's were worked on today. MP 307 (high bootstrap fraction) required good steady ITB's. We couldn't these high quality ITB's, presumably because of impurity conditions, so we eventually switched to MP 384 around 15:00. We got a good start on this MP, which involves running similar plasma conditions in three different magnetic configurations: SNL, SNL barely touching the inboard nose, and hard limited on the inboard nose. The PCS programming on the last shot (1040325033) contains the following: All segments (2,3,4): have 0.8 MA, 5.4-5.5 T, nl_04=0.55e20 m-2, with the following differences: Segment 2: lower null Segment 3: separatrix just touches inboard nose Segment 4: limited on inboard nose This shot's PCS programming should be used to continue Brian's MP 384. Scorecard: 32 plasmas 0 fizzles 1 dud (breakers pulled out) 0 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) ---------- 33 total ------------------------------------------------------------------------------- Engineering setup for Thursday, 25 Mar 2004 MP 307: High bootstrap-fraction regimes MP 384: Plasma flows and L-H threshold in different configurations Session leader: R. Parker (MP 307) / B. Labombard (MP 384) 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 systems the same as 1040309029 (0.8 MA, 4.4 T, lower X-point) A-coils should be disabled. 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) Disable NINJA Enable the following gate valves, assuming no vacuum problems: ECE, VUV, DNB Necessary diagnostics: Visible bremsstrahlung, ECE, Thomson, HIREX Desirable diagnostics: DNB/MSE ------------------------------------------------------------------------------- RF Setup: All four transmitters in RUN-ON by 08:00. D and E at 80 MHz, J3 and J4 at 70 MHz. ------------------------------------------------------------------------------- Run Plan: Begin by trying to reproduce shot 1040309029, an ITB shot with 4 MW of two-frequency RF at 4.4 T. Then ramp current down after ITB formation in increments of 100 kA. Compare with forming ITB with steady current, beginning at 800 kA and decreasing in increments of 100 kA. ------------------------------------------------------------------------------- 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 1040309029, PCS segment 1 from shot 1040324031 ------------------------------------------------------------------------------- Shot 01 -- Plasma. Good shot. Good 2-freq RF. Got an ITB, but it dropped out early. Next shot: no PCS changes. Shot 02 -- Plasma. Good shot. Good 2-freq RF. Got an ITB, but it didn't last long enough. Next shot: no PCS changes. Increase off-axis RF power by 0.5 MW (to 2.8 MW) Shot 03 -- Plasma. Disrupted at t=1.2 s. Got a good ITB, but it died before the on-axis heating turned on. Next shot: turn on 0.8 MW of on-axis at t=1.0, followed by additional 0.8 MW at t=1.2 s (Catherine's suggestion). Shot 04 -- Plasma. Good shot. Good RF. Got an ITB, but it still didn't last. Next shot: Turn on the 2nd half of the on-axis RF at t=1.1 s, rather than 1.2 s. Shot 05 -- Plasma. Good shot. Good RF. Good ITB, but it doesn't last. Next shot: turn on all the on-axis RF at t=1.0 s. Shot 06 -- Plasma. Good shot. Good RF. The EDA H-mode lasted noticeably longer this time, but the peaking arrested at t=1.0 s and even started to relax. Next shot: move RXL out by 1 cm. Keep RF programming the same. Shot 07 -- Plasma. Good shot. Good RF. EDA lasted a very long time, but there was no peaking. Next shot: repeat, no changes Shot 08 -- Plasma. Disrupted at t=0.97 s. It looks like it was going into a really strong ITB, but there was an injection. Next shot: repeat one last time Shot 09 -- Plasma. Disrupted at t=1.0 s, just like the previous shot. Next shot: move RXL in by 0.5 cm (partially undoing the change I made after shot 06). Shot 10 -- Plasma. Disrupted at t=1.23, which is progress. An ITB started, but the on-axis RF reversed it. Next shot: go back to staggering the on-axis RF turnons Shot 11 -- Plasma. Disrupted at t=0.9 s. Next shot: go back to shot 06, including the RF programming. Shot 12 -- Plasma. Disrupted, but not until t=1.3 s. ITB formed, but then transitioned back at t=1.0 s when the on-axis RF turns on. Next shot: repeat Shot 13 -- Plasma. Disrupted early, at t=0.7 s. Next shot: move RXL out by 2 cm Shot 14 -- Plasma. Good shot -- full length. Long H-mode, but no peaking. Several dropouts on the RF may have prevented the ITB. Next shot: repeat, no changes Shot 15 -- Plasma. Disrupted at t=0.84 s. Next shot: reload shot 01 (which is the same as 1040309029), including RF programming. Shot 16 -- Plasma. Good shot. Multiple EDA's, but only several EN ITB's. Next shot: one last try. Also tweak Ip trace near the segment switch to try and get rid of the early glitch. Shot 17 -- Plasma. Good shot. Multiple EDA's, but no ITB's. The glitch in the early Ip is fixed. Next shot: raise nl_04 target density by 10% (nl_04=1.1e20 m-2) and program some PG3 gas puffing early in segment 2. Shot 18 -- Plasma. Good shot. Got a strong ITB, but again it didn't last. Got the higher target density. Next shot: no PCS changes, but change the on-axis RF so that 0.8 MW comes on at t=1.1 s and the other 0.8 MW comes on at t=1.3 s. NOTE: apparently I did not actually reload shot 01 for shot 16, contrary to my logbook entry. This means that RXL is still +2 cm from where we started today's run. Shot 19 -- Plasma. Good shot. Got a brief ITB, but then it dropped out. Next shot: load RXL from shot 01 today (which I meant to do prior to shot 16, but apparently didn't) Shot 20 -- Plasma. Good shot. Best ITB of the day so far. It terminated at t=1.3 s. Next shot: reduce Btor by 2% to 4.4 T Shot 21 -- Plasma. Good shot. Good EDA, but no ITB. Looks like lower Btor is not the way to go. Next shot: try raising Btor to 4.6 T Shot 22 -- Plasma. Disrupted during rampdown. One long EDA, but not much of an ITB. Looks like the optimal field really is 4.5 T. Next shot: put Btor back at 4.5 T, and lower Ip to 0.7 MA for the entire shot. Shot 23 -- Plasma. Good shot. No H-mode, even though there was 2.0 MW of off-axis RF. End of Ron's MP 307. Switch to Brian's MP 384. Next shot: load 1040213028 and tweak Btor back to 5.4 T (instead of 5.7 T). This shot has Ip=0.8 MA and nl_04=0.6e20 m-2, SNL. Shot 24 -- Plasma. Good shot. D and E RF ramped from 0.5 to 1.5 MW, as requested. This is now normal on-axis heating, since Bt=5.49 T. H-mode threshold was around 0.85 MW. Next shot: repeat for Brian's probes Shot 25 -- Plasma. Good shot. Threshold is more like 1.0 MW, maybe because the density is slightly higher. Next shot: decrease nl_04 to 0.5e20 m-2 (from 0.6). Also tweak RCUR to increase outer gap a couple of mm. Shot 26 -- Plasma. Really weird startup with huge amounts of runaways and hard x-rays. I didn't change anything early in the shot, so I don't understand why this happened. The rest of the shot was fairly normal. Outer gap behavior is acceptable to Brian. Next shot: no PCS changes Shot 27 -- Plasma. Good shot. Normal startup, even though I didn't change a thing. However, there was no H-mode. Prf=0.5-1.5 MW. Next shot: increase nl_04 to 0.55e20 m-2 (from 0.50e20) Shot 28 -- Plasma. Good shot. Two short H-modes. Next shot: load shot 1040213027 segment 2 into segment 3. (This shot had the separatrix almost touching the inboard nose.) Change Bt to 150 kA and reload nl_04 from shot 28 today. Turn on segment 3 and turn off segment. Shot 29 -- Plasma. Good shot. Several short H-modes. The gap to the inboard nose is about 1 cm, which is a little more than we want. H-mode threshold was similar to previous shots. Next shot: move RXL in by 1 cm to try and reduce the gap. Shot 30 -- Plasma. Good shot. The separatrix just kissed the inboard nose...exactly what we wanted. Still got H-modes, and still had a similar power threshold. Next shot: load segment 3 into segment 4, turn on segment 4 and turn off segment 3, and move RXL in segment 4 another 2 cm in, in order to limit the plasma on the inboard nose. Shot 31 -- Plasma. Good shot. Limited on inboard nose. Still got an H-mode, with similar threshold power as diverted plasmas. The inner gap is too big. Next shot: increase RXL by 1 cm (in segment 4) to try and reduce the inner wall gap at the midplane while still staying limited on the inboard nose. Shot 32 -- Dud. Breakers pulled out at the beginning of pulse. Alternator voltage had drooped. Next shot: try again. Shot 33 -- Plasma. Good shot. Limited on inboard nose. Inner gap to midplane was slightly smaller, but probably not small enough. Got an H-mode, same power threshold. The PCS programming on this shot contains the following: All segments (2,3,4): 0.8 MA, 5.4-5.5 T, nl_04=0.55e20 m-2, and Segment 2: lower null Segment 3: separatrix just touches inboard nose Segment 4: limited on inboard nose This shot's PCS programming should be used to continue Brian's MP 384. End of run. |
| Session Leader Comments | |||
| Mar 25 2004 09:38:56:183AM | 1040325001 | Ron Parker | We are trying to optimize ITB discharge for high bootstrap fraction/ Initial approach will be to reproduce the 1040309029 shot, then lower current either by ramping down during ITB or by steps. First shot wasn't bad, but ITB disappeared before the central heating pulse. |
| Mar 25 2004 09:26:08:523AM | 1040325002 | Ron Parker | Shot 2 again had a back transition before central power pulse turned on. |
| Mar 25 2004 09:36:46:020AM | 1040325003 | Ron Parker | On that shot, barrier formed but discharge collapsed before J port came on. On next shot, we'll step J port, .8 MW at t =1 s, followed by additional 0.8 MW at 1.2 s. |
| Mar 25 2004 09:54:11:380AM | 1040325004 | Ron Parker | Shot 4 got closer to what we want, but back transisted although remaining peaked. |
| Mar 25 2004 10:03:38:670AM | 1040325005 | Ron Parker | Shots are peaking nicely, but quenching before full J port power. Next: Full J port power at 1 s. |
| Mar 25 2004 10:37:01:993AM | 1040325006 | Ron Parker | Shot 6 had full RF power from J port which stopped the peaking. Central density only reached 4e20. |
| Mar 25 2004 10:27:14:297AM | 1040325007 | Ron Parker | Shot 7 had an early back transition. We had moved the x point out 1 cm to try to reduce impurity influx. |
| Mar 25 2004 10:37:59:310AM | 1040325008 | Ron Parker | Shot 8 disrupted. |
| Mar 25 2004 10:55:34:910AM | 1040325009 | Ron Parker | Shot 9 disrupted again. Move X point back 0.5 cm (to inside) |
| Mar 25 2004 11:07:05:130AM | 1040325010 | Ron Parker | Plasma still disrupted, but later. On axis RF power will be stepped, from 1 turning on at 1 s to 1.5 at 150 ms. |
| Mar 25 2004 11:19:40:570AM | 1040325011 | Ron Parker | Still disrupting, back to shot 6. |
| Mar 25 2004 11:35:57:270AM | 1040325012 | Ron Parker | Shot 12 ran better but still disrupted. |
| Mar 25 2004 11:40:36:403AM | 1040325013 | Ron Parker | Still disrupts, can't recover from the disruptions! |
| Mar 25 2004 11:49:51:750AM | 1040325013 | Ron Parker | Next shot, move discharge 2 cm outside. |
| Mar 25 2004 12:05:39:890PM | 1040325014 | Ron Parker | Shot 14 went and did not disrupt. But no ITB. Run shot again. |
| Mar 25 2004 12:14:11:600PM | 1040325015 | Ron Parker | Shot 14 disrupted. We'll try to reload shot 1 (lower RF power, diverted inside). |
| Mar 25 2004 12:33:50:860PM | 1040325016 | Ron Parker | Shot 16 had no ITB. Try one more time. If unsuccessful, turn run over to Brian. |
| Mar 25 2004 12:41:05:880PM | 1040325017 | Ron Parker | Again, no ITB. As a last resort, we'll increase target density by 10%. |
| Mar 25 2004 01:59:06:200PM | 1040325018 | Ron Parker | Shot 18 ran with the increased target density and brief ITB. |
| Mar 25 2004 01:59:53:420PM | 1040325019 | Ron Parker | Shot 19 also had a brief ITB, but back transition before on axis htg. |
| Mar 25 2004 02:02:54:237PM | 1040325020 | Ron Parker | Shot 20 looked promising with an ITB lasting about .25 s Next: lower field by ~ 2%. |
| Mar 25 2004 02:08:37:857PM | 1040325021 | Ron Parker | No ITB, increase field by 4% (2% relative to earler settings) |
| Mar 25 2004 02:23:38:527PM | 1040325022 | Ron Parker | Shot 22 had a weak ITB. Looks like optimum field is 4.5 T. Now lower current to 700 kA. |
| Mar 25 2004 02:41:27:710PM | 1040325023 | Ron Parker | Shot 23 had lower current, 700 ka. No H-mode, no barrier. No more shots on this MP Brian takes over. |
| Mar 25 2004 03:13:44:980PM | 1040325024 | Brian Labombard | Start MP#384 - Flows and L-H thresholds Shot 24 LSN, 0.8 MA, 5.4 tesla, L-H at 1.07 s, 0.89 MW ASP, FSP, ISP scanning at 0.7, 0.9 seconds ASP - too far out FSP - near sep. ISP - ok Next shot: repeat with probes further in |
| Mar 25 2004 03:36:05:513PM | 1040325025 | Brian Labombard | Shot 25 LSN, 0.8 MA, 5.4 tesla, L-H at 1.12 s, 1.0 MW, and NL04=0.8 ASP, FSP, ISP scanning at 0.6, 0.8, 1.0 seconds ASP - funny FSP - ok ISP - ok Next shot: repeat |
| Mar 25 2004 03:45:01:860PM | 1040325026 | Brian Labombard | Shot 26 LSN, 0.8 MA, 5.4 tesla, L-H at 1.04 s, 0.8 MW, and NL04=0.57 ASP, FSP, ISP scanning at 0.6, 0.8, 1.0 seconds ASP - ok now, but too far out FSP - too far out ISP - ok Next shot: repeat |
| Mar 25 2004 04:02:12:987PM | 1040325027 | Brian Labombard | Shot 27 LSN, 0.8 MA, 5.4 tesla, No H-mode ASP, FSP, ISP scanning at 0.6, 0.8, 1.0 seconds ASP - ok FSP - way over-inserted but ok!(?) ISP - ok Next shot: nl04 to 0.55 |
| Mar 25 2004 04:10:39:483PM | 1040325028 | Brian Labombard | Shot 28 LSN, 0.8 MA, 5.4 tesla, L-H at 1.27s, 1.3MW NL04=0.7 ASP, FSP, ISP scanning at 0.6, 0.8, 1.0 seconds ASP - ok FSP - ok ISP - ok Next shot: go to SMALL inner div. nose gap |
| Mar 25 2004 04:25:36:767PM | 1040325029 | Brian Labombard | Shot 29 SMALL inner nose gap, LSN, 0.8 MA, 5.4 tesla, L-H at 1.19s, 1.0MW NL04=0.72 ASP, FSP, ISP scanning at 0.6, 0.8, 1.0 seconds ASP - ok FSP - ok ISP - ok Next shot: reduce inner div. nose gap |
| Mar 25 2004 04:45:18:670PM | 1040325030 | Brian Labombard | Shot 30 SMALL inner nose gap, LSN, 0.8 MA, 5.4 tesla, L-H at 1.2s, 1.18MW NL04=0.64 ASP, FSP, ISP scanning at 0.6, 0.8, 1.0 seconds ASP - ok, could be deeper FSP - ok, could be deeper ISP - ok Next shot: go to LIMITED on inner nose. |
| Mar 25 2004 05:32:40:580PM | 1040325033 | Brian Labombard | Shot 33 LIMITED on inner nose, LSN, 0.8 MA, 5.4 tesla, L-H at 1.19s, 1.15MW NL04=0.67 ASP, FSP, ISP scanning at 0.6, 0.8, 1.0 seconds ASP - ok, over-inserted FSP - ok, cover-inserted ISP - ok, too far out |
| Physics Operator Comments | |||
| Mar 24 2004 07:31:32:483PM | Robert Granetz | Engineering setup for Thursday, 25 Mar 2004 MP 307: High bootstrap-fraction regimes Session leader: R. Parker 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 systems the same as 1040309029 (0.8 MA, 4.4 T, lower X-point) A-coils should be disabled. 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) Disable NINJA Enable the following gate valves, assuming no vacuum problems: ECE, VUV, DNB Necessary diagnostics: Visible bremsstrahlung, ECE, Thomson, HIREX Desirable diagnostics: DNB/MSE ------------------------------------------------------------------------------- RF Setup: All four transmitters in RUN-ON by 08:00. D and E at 80 MHz, J3 and J4 at 70 MHz. ------------------------------------------------------------------------------- Run Plan: Begin by trying to reproduce shot 1040309029, an ITB shot with 4 MW of two-frequency RF at 4.4 T. Then ramp current down after ITB formation in increments of 100 kA. Compare with forming ITB with steady current, beginning at 800 kA and decreasing in increments of 100 kA. | |
| Mar 25 2004 09:00:16:593AM | 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 1040309029, PCS segment 1 from shot 1040324031 | |
| Mar 25 2004 09:15:11:150AM | 1040325001 | Robert Granetz | Shot 01 -- Plasma. Good shot. Good 2-freq RF. Got an ITB, but it dropped out early. Next shot: no PCS changes. |
| Mar 25 2004 09:53:36:957AM | 1040325002 | Robert Granetz | Shot 02 -- Plasma. Good shot. Good 2-freq RF. Got an ITB, but it didn't last long enough. Next shot: no PCS changes. Increase off-axis RF power by 0.5 MW (to 2.8 MW) |
| Mar 25 2004 09:36:49:897AM | 1040325003 | Robert Granetz | Shot 03 -- Plasma. Disrupted at t=1.2 s. Got a good ITB, but it died before the on-axis heating turned on. Next shot: turn on 0.8 MW of on-axis at t=1.0, followed by additional 0.8 MW at t=1.2 s (Catherine's suggestion). |
| Mar 25 2004 09:53:14:503AM | 1040325004 | Robert Granetz | Shot 04 -- Plasma. Good shot. Good RF. Got an ITB, but it still didn't last. Next shot: Turn on the 2nd half of the on-axis RF at t=1.1 s, rather than 1.2 s. |
| Mar 25 2004 10:02:51:373AM | 1040325005 | Robert Granetz | Shot 05 -- Plasma. Good shot. Good RF. Good ITB, but it doesn't last. Next shot: turn on all the on-axis RF at t=1.0 s. |
| Mar 25 2004 10:20:08:433AM | 1040325006 | Robert Granetz | Shot 06 -- Plasma. Good shot. Good RF. The EDA H-mode lasted noticeably longer this time, but the peaking arrested at t=1.0 s and even started to relax. Next shot: move RXL out by 1 cm. Keep RF programming the same. |
| Mar 25 2004 10:29:00:270AM | 1040325007 | Robert Granetz | Shot 07 -- Plasma. Good shot. Good RF. EDA lasted a very long time, but there was no peaking. Next shot: repeat, no changes |
| Mar 25 2004 10:40:36:910AM | 1040325008 | Robert Granetz | Shot 08 -- Plasma. Disrupted at t=0.97 s. It looks like it was going into a really strong ITB, but there was an injection. Next shot: repeat one last time |
| Mar 25 2004 10:52:35:880AM | 1040325009 | Robert Granetz | Shot 09 -- Plasma. Disrupted at t=1.0 s, just like the previous shot. Next shot: move RXL in by 0.5 cm (partially undoing the change I made after shot 06). |
| Mar 25 2004 11:05:09:663AM | 1040325010 | Robert Granetz | Shot 10 -- Plasma. Disrupted at t=1.23, which is progress. An ITB started, but the on-axis RF reversed it. Next shot: go back to staggering the on-axis RF turnons |
| Mar 25 2004 11:17:52:337AM | 1040325011 | Robert Granetz | Shot 11 -- Plasma. Disrupted at t=0.9 s. Next shot: go back to shot 06, including the RF programming. |
| Mar 25 2004 11:31:22:727AM | 1040325012 | Robert Granetz | Shot 12 -- Plasma. Disrupted, but not until t=1.3 s. ITB formed, but then transitioned back at t=1.0 s when the on-axis RF turns on. Next shot: repeat |
| Mar 25 2004 11:50:38:410AM | 1040325013 | Robert Granetz | Shot 13 -- Plasma. Disrupted early, at t=0.7 s. Next shot: move RXL out by 2 cm |
| Mar 25 2004 12:08:57:560PM | 1040325014 | Robert Granetz | Shot 14 -- Plasma. Good shot -- full length. Long H-mode, but no peaking. Several dropouts on the RF may have prevented the ITB. Next shot: repeat, no changes |
| Mar 25 2004 12:14:18:800PM | 1040325015 | Robert Granetz | Shot 15 -- Plasma. Disrupted at t=0.84 s. Next shot: reload shot 01 (which is the same as 1040309029), including RF programming. |
| Mar 25 2004 12:33:06:110PM | 1040325016 | Robert Granetz | Shot 16 -- Plasma. Good shot. Multiple EDA's, but only several EN ITB's. Next shot: one last try. Also tweak Ip trace near the segment switch to try and get rid of the early glitch. |
| Mar 25 2004 01:22:57:787PM | 1040325016 | Robert Granetz | NOTE: apparently I did not actually reload shot 01 for shot 16, contrary to my logbook entry. This means that RXL is still +2 cm from where we started today's run. |
| Mar 25 2004 12:44:12:597PM | 1040325017 | Robert Granetz | Shot 17 -- Plasma. Good shot. Multiple EDA's, but no ITB's. The glitch in the early Ip is fixed. Next shot: raise nl_04 target density by 10% (nl_04=1.1e20 m-2) and program some PG3 gas puffing early in segment 2. |
| Mar 25 2004 01:12:32:343PM | 1040325018 | Robert Granetz | Shot 18 -- Plasma. Good shot. Got a strong ITB, but again it didn't last. Got the higher target density. Next shot: no PCS changes, but change the on-axis RF so that 0.8 MW comes on at t=1.1 s and the other 0.8 MW comes on at t=1.3 s. |
| Mar 25 2004 01:22:17:190PM | 1040325018 | Robert Granetz | NOTE: apparently I did not actually reload shot 01 for shot 16, contrary to my logbook entry. This means that RXL is still +2 cm from where we started today's run. |
| Mar 25 2004 01:40:56:273PM | 1040325019 | Robert Granetz | Shot 19 -- Plasma. Good shot. Got a brief ITB, but then it dropped out. Next shot: load RXL from shot 01 today (which I meant to do prior to shot 16, but apparently didn't) |
| Mar 25 2004 02:02:43:317PM | 1040325020 | Robert Granetz | Shot 20 -- Plasma. Good shot. Best ITB of the day so far. It terminated at t=1.3 s. Next shot: reduce Btor by 2% to 4.4 T |
| Mar 25 2004 02:09:43:750PM | 1040325021 | Robert Granetz | Shot 21 -- Plasma. Good shot. Good EDA, but no ITB. Looks like lower Btor is not the way to go. Next shot: try raising Btor to 4.6 T |
| Mar 25 2004 02:25:07:670PM | 1040325022 | Robert Granetz | Shot 22 -- Plasma. Disrupted during rampdown. One long EDA, but not much of an ITB. Looks like the optimal field really is 4.5 T. Next shot: put Btor back at 4.5 T, and lower Ip to 0.7 MA for the entire shot. |
| Mar 25 2004 02:49:48:227PM | 1040325023 | Robert Granetz | Shot 23 -- Plasma. Good shot. No H-mode, even though there was 2.0 MW of off-axis RF. End of Ron's MP 307. Switch to Brian's MP 384. Next shot: load 1040213028 and tweak Btor back to 5.4 T (instead of 5.7 T). This shot has Ip=0.8 MA and nl_04=0.6e20 m-2, SNL. |
| Mar 25 2004 03:02:09:213PM | 1040325024 | Robert Granetz | Shot 24 -- Plasma. Good shot. D and E RF ramped from 0.5 to 1.5 MW, as requested. This is now normal on-axis heating, since Bt=5.49 T. H-mode threshold was around 0.85 MW. Next shot: repeat for Brian's probes |
| Mar 25 2004 03:30:34:053PM | 1040325025 | Robert Granetz | Shot 25 -- Plasma. Good shot. Threshold is more like 1.0 MW, maybe because the density is slightly higher. Next shot: decrease nl_04 to 0.5e20 m-2 (from 0.6). Also tweak RCUR to increase outer gap a couple of mm. |
| Mar 25 2004 03:50:40:727PM | 1040325026 | Robert Granetz | Shot 26 -- Plasma. Really weird startup with huge amounts of runaways and hard x-rays. I didn't change anything early in the shot, so I don't understand why this happened. The rest of the shot was fairly normal. Outer gap behavior is acceptable to Brian. Next shot: no PCS changes |
| Mar 25 2004 03:59:14:180PM | 1040325027 | Robert Granetz | Shot 27 -- Plasma. Good shot. Normal startup, even though I didn't change a thing. However, there was no H-mode. Prf=0.5-1.5 MW. Next shot: increase nl_04 to 0.55e20 m-2 (from 0.50e20) |
| Mar 25 2004 04:15:41:370PM | 1040325028 | Robert Granetz | Shot 28 -- Plasma. Good shot. Two short H-modes. Next shot: load shot 1040213027 segment 2 into segment 3. (This shot had the separatrix almost touching the inboard nose.) Change Bt to 150 kA and reload nl_04 from shot 28 today. Turn on segment 3 and turn off segment. |
| Mar 25 2004 04:24:54:950PM | 1040325029 | Robert Granetz | Shot 29 -- Plasma. Good shot. Several short H-modes. The gap to the inboard nose is about 1 cm, which is a little more than we want. H-mode threshold was similar to previous shots. Next shot: move RXL in by 1 cm to try and reduce the gap. |
| Mar 25 2004 04:44:24:447PM | 1040325030 | Robert Granetz | Shot 30 -- Plasma. Good shot. The separatrix just kissed the inboard nose...exactly what we wanted. Still got H-modes, and still had a similar power threshold. Next shot: load segment 3 into segment 4, turn on segment 4 and turn off segment 3, and move RXL in segment 4 another 2 cm in, in order to limit the plasma on the inboard nose. |
| Mar 25 2004 04:57:21:233PM | 1040325031 | Robert Granetz | Shot 31 -- Plasma. Good shot. Limited on inboard nose. Still got an H-mode, with similar threshold power as diverted plasmas. The inner gap is too big. Next shot: increase RXL by 1 cm (in segment 4) to try and reduce the inner wall gap at the midplane while still staying limited on the inboard nose. |
| Mar 25 2004 05:46:41:180PM | 1040325032 | Robert Granetz | Shot 32 -- Dud. Breakers pulled out at the beginning of pulse. Alternator voltage had drooped. Next shot: try again. |
| Mar 25 2004 05:43:11:753PM | 1040325033 | Robert Granetz | Shot 33 -- Plasma. Good shot. Limited on inboard nose. Inner gap to midplane was slightly smaller, but probably not small enough. Got an H-mode, same power threshold. The PCS programming on this shot contains the following: All segments (2,3,4): 0.8 MA, 5.4-5.5 T, nl_04=0.55e20 m-2, and Segment 2: lower null Segment 3: separatrix just touches inboard nose Segment 4: limited on inboard nose This shot's PCS programming should be used to continue Brian's MP 384. End of run. |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 09:01:55:630AM | Plasma | Ok | |
| 2 | 09:16:03:153AM | Plasma | Ok | |
| 3 | 09:28:54:500AM | Plasma | Ok | |
| 4 | 09:44:08:710AM | Plasma | Ok | |
| 5 | 09:56:44:730AM | Plasma | Ok | |
| 6 | 10:09:05:780AM | Plasma | Ok | |
| 7 | 10:21:32:063AM | Plasma | Ok | |
| 8 | 10:33:56:283AM | Plasma | Ok | |
| 9 | 10:47:22:100AM | Plasma | Ok | |
| 10 | 10:59:52:200AM | Plasma | Ok | |
| 11 | 11:12:27:110AM | Plasma | Ok | |
| 12 | 11:25:00:690AM | Plasma | Ok | |
| 13 | 11:38:01:470AM | Plasma | Ok | |
| 14 | 11:54:59:073AM | Plasma | Ok | |
| 15 | 12:08:43:200PM | Plasma | Ok | |
| 16 | 12:21:19:170PM | Plasma | Ok | |
| 17 | 12:34:53:013PM | Plasma | Ok | |
| 18 | 01:01:26:280PM | Plasma | Ok | |
| 19 | 01:32:41:493PM | Plasma | Ok | |
| 20 | 01:49:58:837PM | Plasma | Ok | |
| 21 | 02:03:29:783PM | Plasma | Ok | |
| 22 | 02:17:27:280PM | Plasma | Ok | |
| 23 | 02:32:15:683PM | Plasma | Ok | |
| 24 | 02:54:41:930PM | Plasma | Ok | |
| 25 | 03:14:49:943PM | Plasma | Ok | |
| 26 | 03:31:38:127PM | Plasma | Ok | |
| 27 | 03:50:00:343PM | Plasma | Ok | |
| 28 | 04:03:01:183PM | Plasma | Ok | |
| 29 | 04:17:09:690PM | Plasma | Ok | |
| 30 | 04:29:40:537PM | Plasma | Ok | |
| 31 | 04:45:27:780PM | Plasma | Ok | |
| 32 | 04:58:20:130PM | Plasma | Bad | Alt ramped down at pulse |
| 33 | 05:11:48:623PM | Plasma | Ok | |