| Miniproposals | ||||||||||
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| Operators | |
| Session leader(s): | Catherine Fiore,Chuck Kessel |
| Physics operator(s): | Ron Parker |
| Engineering operator(s): | Bill Parkin,Ed Fitzgerald,Bill Byford |
| Engineering Operator Run Comment |
| MP454: Low Ip H+ITB modes, their modulation and combination with LH |
| Session Leader Plans |
| Entered: May 15 2008 02:26:14:940PM |
| Author: Chuck Kessel |
| MP454: Low Ip H+ITB modes, their modulation and combination with LH
4.1 Machine and Plasma Parameters Give values or range for: Toroidal Field: 5.4 T Plasma Current: 0.450 MA Working Gas Species: D, H-minority. Density: Target 5e19 m-2 cryopump on Equilibrium configuration (if possible, refer to database equilibria): 1080221009, change Ip ramp up time from 500 ms to 150 ms 4.2 Auxiliary Systems ICRF Power, pulse length, phasing: J-port , maximum power. D and E maximum power, all for full pulse (up to 2.5 s) LHCD Power, pulse length, phasing: maximum power, 90 deg (maybe higher), longest pulse available. Pellet Injection (species): no Impurity blow-off injection: no Diagnostic Neutral Beam: Highly desirable Special gas puffing: NINJA (with D2) should be available. Non-axisymmetric Coils (Connections, Current); Yes; optimized to reduce locked modes. Other: 4.3 Diagnostics List required diagnostics, and any special setup or configuration, e.g. non-standard digitization rate. Essential: Thomson, Magnetics, Hard x-rays, ECE, TCI, probes in LH grill, Hirex (rotation data) Desirable: MSE, CXRS, SOL probes. Experimental Plan: 1. Establish BT = 5.4T, 450 kA plasma with 150 ms ramp, use 1080221009 as reference 2. Setup ICRF for 2+ MW off-axis beginning at 250 ms (70 MHz, J port) to make H+ITB mode, establish density, and H-mode onset and ITB onset timing (use 4.5 T if difficulties with 5.4 T) 3. With 2+ MW of ICRF off-axis power, scan injected ICRF on-axis power and its timing to stabilize ITB 4.Inject LH power into stabilized ICRF ITB plasma ā?¢ LH on time after ITB stabilization, maximum power, 90 deg phasing ā?¢ Try higher n|| if accessibility problems are a possibility 5.Using case from above step, after in stabilized ITB mode, raise on-axis power slightly to return to H-mode or ITB with weaker density peaking ---> determine how much power to increase on-axis source 6.Using case from above step, in stabilized ITB mode, raise on-axis power slightly to return to H-mode or ITB with weaker density peaking, then reduce on-axis power to recover original ITB density peaking (this may require dropping on-axis power to zero first) ---> this probably requires flattop extension, end of Ip flattop extended from 1.5 to 2.5 s |
| Physics Operators Plans |
| Entered: May 15 2008 06:22:23:370PM |
| Author: Ron Parker |
| ------------------------------------------------------------------------ --
Engineering Setup for Friday 16 May 2008 ----------------- MP454: Low Ip H+ITB modes, their modulation and combination with LH SL: C. Kessel PO: R. Parker ----------------- Engineering Setup ----------------- Run begins at 09:00 and ends at 17:00 Power systems as on: 1080514031 Acoil: +Dtop -Dbot -Jtop +Jbot (standard) Hybrid Enabled Gas setup: Fill B-Top with 6 psi D2 Hybrid enabled (PG4) fill B-side lower with 1 psi Ar Hybrid DISABLED (PG1) leave B-side upper as is Hybrid DISABLED (PG2) fill B-main (C-side) with 40 psi D2 Hybrid enabled (PG3) fill NINJA with 10 psi D2 DISABLED Enable gatevalves and shutters: ECE, VUV, DNB, Z-bolo Post boronization ECDC ---------------------------- 1st Gas Setup: Gas: helium sweep: 44/103/45 cm tdwell/tsweep 20/120 s Pressure: 5e-5 Torr Duration: 1 hr 2nd Gas Setup Gas: d2 sweep: 44/103/45cm tdwell/tsweep: 20/120 s Pressure: 2e-4 Torr Duration: 1hr Torvac gatevalve toggle (yes/no): Boronization(yes/no): yes Overnight ECDC (yes/no): no ICRF(yes/no): yes LH(yes/no): yes DNB(yes/no): if available Cryopump (yes/no): yes Vessel temperature: 35/35/35 ------------------------------ ECDC Parameters (if requested) ------------------------------ gas and pressure: D2 at 2e-4 Torr sweep: 44/45/103 cm scan: 20/120 s -------------------------------------- Boronization Parameters (if requested) -------------------------------------- 20% diborane/80% helium TC6 foreline pressure: 50 mTorr rmin/rdwell/rmax: 44/75/80 cm tdwell/tsweep: 60 /120s EF4 current: 200 A Pressure change in the bottle: 60 psi ------------------------------- Note: we'll start with a few shots to complete Liang Lin's run on the 14th. Then switch to Chuck's run ----------------------------- |
| Session Leader Summaries |
| Entered: May 16 2008 09:00:43:200AM |
| Author: Catherine Fiore |
| The first few shots will be to complete the run from 1080514, to get PCI data with central ICRF in an ITB. |
| Entered: May 16 2008 09:08:20:957AM |
| Author: Catherine Fiore |
| Nice target shot but not enough ICRF power to make the EDA H-mode with ITB. Yijun says the neutral density is too high for J-port to operate, as is usual right after boronization. |
| Entered: May 16 2008 09:23:12:420AM |
| Author: Catherine Fiore |
| Nice ITB. The neutral density is too high for J-port to operate. The RF group expects the neutral density to come down shot to shot if we keep conditions steady. Argon for Hirex_SR was added this shot, 0.6 ms. |
| Entered: May 16 2008 09:48:21:657AM |
| Author: Catherine Fiore |
| ITB developed. J-port came on at 1.1s and stopped the further growth of the density, then the plasma disrupted. J-port will be fire at 1.2 s next shot. |
| Entered: May 16 2008 09:49:31:423AM |
| Author: Catherine Fiore |
| Nice ITB. The neutral density is too high for J-port to operate. |
| Entered: May 16 2008 09:59:59:243AM |
| Author: Catherine Fiore |
| Perfect shot,ITB developed. J-port came on at 1.2s and stopped the further growth of the density. We need a repeat to get the PCI data with a second masking. |
| Entered: May 16 2008 10:11:10:300AM |
| Author: Catherine Fiore |
| Disruption early. |
| Entered: May 16 2008 10:22:33:760AM |
| Author: Catherine Fiore |
| Disruption early. |
| Entered: May 16 2008 10:45:52:657AM |
| Author: Catherine Fiore |
| Good ITB, stabilized by J-port but disrupted shortly after it came on. We'll try one more time. |
| Entered: May 16 2008 10:51:23:957AM |
| Author: Catherine Fiore |
| Good ITB,J-port had no power so the density rose until it disrupted. |
| Entered: May 16 2008 11:04:02:653AM |
| Author: Catherine Fiore |
| ITB with multiple back transitions,J-port had no power so the density rose until it disrupted. |
| Entered: May 16 2008 11:15:16:880AM |
| Author: Catherine Fiore |
| This looks like a perfect shot. We're turning it over to Chuck Kessel now |
| Entered: May 16 2008 02:53:29:737PM |
| Author: Catherine Fiore |
| The first few shots will be to complete the run from 1080514, to get PCI
data with central ICRF in an ITB. This was highly successful, with ITBs on the majority of shots. Liang will be able to use PCI data from shots 5 and 11 as ITBs stabilized with central heating to support his thesis work. 1080516001 Nice target shot but not enough ICRF power to make the EDA H-mode with ITB. Yijun says the neutral density is too high for J-port to operate, as is usual right after boronization. 1080516002 Nice ITB. The neutral density is too high for J-port to operate. The RF group expects the neutral density to come down shot to shot if we keep conditions steady. Argon for Hirex_SR was added this shot, 0.6 ms. 1080516003 Nice ITB. The neutral density is too high for J-port to operate. 1080516004 ITB developed. J-port came on at 1.1s and stopped the further growth of the density, then the plasma disrupted. J-port will be fire at 1.2 s next shot. 1080516005 Perfect shot,ITB developed. J-port came on at 1.2s and stopped the further growth of the density. We need a repeat to get the PCI data with a second masking. 1080516006 Disruption early. 1080516007 Disruption early. 1080516008 Good ITB, stabilized by J-port but disrupted shortly after it came on. We'll try one more time. 1080515009 Good ITB,J-port had no power so the density rose until it disrupted. 1080516010 ITB with multiple back transitions,J-port had no power so the density rose until it disrupted. 1080516011 Perfect shot, reproducing 1080516005 with masking set correctly for PCI. We're turning the run over to Chuck Kessel now. |
| Entered: May 19 2008 09:05:24:997AM |
| Author: Chuck Kessel |
| MP454: SL Summary
The first 11 shots were given to another ITB experiment, causing this experiment to begin about 11:45 am. It then took until shot 017 to get the discharge set up. Here we were ramping up to 450 kA in about 170 ms. The toroidal field was 5.4 T, with J-port providing the off-axis ICRF power on the low field side. For most of the shots LH was applied in the later half of the flattop to condition up. 018, 019: off-axis ICRF injected at 350 ms, about 2 MW. Density request was about nel = 7e19. ITBā??s forming after H-modes in the flattop. The peaking region is smaller (than those at 4.5 T) presumably due to higher Bt. Densities are low for H-modes although these are low Ip discharges, at nel = 8.5-9e19. These ITBs were self-stabilizing, no on-axis ICRF was necessary. 021: used 0.4 MW of on-axis power, seemed similar to those without on-axis power 024: tried 0.25 MW of on-axis power, E-port did not fire, so there was a no on-axis power 025: used 0.75 MW of on-axis power, also looks like the no on-axis power shots 026-030: tried injecting LH into H+ITB discharges. This was not successful. Shot 030 with 0.75 MW of on-axis ICRF power, shows a stronger Te peaking than normal on the Thomson scattering, is it an ITB in Te?? Did not get to ITB turn on and off phase of MP. |
| Physics Operator Summaries |
| Entered: May 16 2008 05:00:08:020PM |
| Author: Ron Parker |
| The run had two parts, the first to complete yesterday's run for Liang Lin, the second to undertake a run with Chuck Kessel as SL. Chuck graciously conceded 5-6 shots for Lin's run, but in the event 11 shots were required. This was because of poor machine operating conditions leading to frequent disruptions.
Chuck took over at shot 12, and shots 12-14 disrupted, continuing the trend. Shots 16-21 were OK, and hopefully some useful data were obtained. After a few more decent shots, shots 27-31 disrupted. After 31, an indication of a transformer cooling problem materialized, and only one more shot could be run, which alas fizzled. Scorecard: 33 plasma attempts, 16 useful plasms, 14 disruptions,1 no power shot, 1 fizzle (the last "shot" of course.) |
| Session Leader Comments | |||
| May 16 2008 11:46:24:327AM | Chuck Kessel | 012: use same Ip ramp as in previous shots today, not a good choice. Bt to 5.4 T, J-port to 2 MW at 250 ms, density request to 6e19. H-mode attempts, ICRF pretty choppy from 250-750 ms. Will go to original Ip ramp request in next shot. | |
| May 16 2008 11:46:45:920AM | 1080516012 | Chuck Kessel | 012: use same Ip ramp as in previous shots today, not a good choice. Bt to 5.4 T, J-port to 2 MW at 250 ms, density request to 6e19. H-mode attempts, ICRF pretty choppy from 250-750 ms. Will go to original Ip ramp request in next shot. |
| May 16 2008 11:52:12:097AM | 1080516013 | Chuck Kessel | 013: Trying original Ip request from MP using shot 1080221009. Ip ramp didn't finish, ugh. |
| May 16 2008 12:09:11:500PM | 1080516014 | Chuck Kessel | 014: not good, mixing segments from old shot 1080221009 and recent shots today. Correct in next shot. |
| May 16 2008 12:37:04:710PM | 1080516016 | Chuck Kessel | 016: discharge ran thru. Ip ramp to 450 kA from reference shot 1080221009, need to make faster, so Ip reaches 450 kA by 150 ms in next shot. density coming up too slow and too low for H-mode. ICRF J-port looks wobbly but in a good range. |
| May 16 2008 12:50:20:593PM | 1080516017 | Chuck Kessel | 017: Ip ramp is very good now, 450 kA by 170 ms. density is rising but is pumped out by ICRF turning on at 200 ms. No real H-mode. |
| May 16 2008 01:35:37:707PM | 1080516019 | Chuck Kessel | 019: better density trajecotry in ramp. J-port at 2.2 MW, good shot. have ITB peaking in core and is self-stabilized, no on-axis ICRF seems to be required. |
| May 16 2008 01:38:12:927PM | 1080516020 | Chuck Kessel | 020: tried to add 0.5 MW of on-axis ICRF to ITB case in 019, J-port didn't stay on. try again next shot. |
| May 16 2008 01:49:20:077PM | 1080516021 | Chuck Kessel | 021: repeat 020 with J-port staying on, slightly lower power on J-port. good discharge, long H+ITB. slow density peaking thru flattop. 0.4 MW on axis power. |
| May 16 2008 02:34:18:673PM | 1080516024 | Chuck Kessel | 024: trying low on-axis ICRF power, not working well. Getting H+ITB, longer H-modes in flattop. E-port did not come on. again shows ITBs that do not require on-axis stabilization. |
| May 16 2008 02:51:46:140PM | 1080516025 | Amanda Hubbard | 750 kW E-port. Long ITB, but Te gets rather cool. LH on late again, kils H-mode though.
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| May 16 2008 02:52:08:220PM | 1080516025 | Chuck Kessel | 025: tried 0.75 MW on axis, E-port worked well. not clear what on-axis power is doing, ITB still appears to peak during H-modes. |
| May 16 2008 03:44:41:350PM | 1080516028 | Chuck Kessel | 028: trying LH into H+ITB plasmas. J-port 2 MW 350-1500 ms, E-port 0.5 MW 600-1500 ms, LH 0.5 MW 850-1350 ms. ICRF wobbly and LH tripping alot. decent ITB 600-800 ms. when LH goes steady H+ITB returns very briefly. |
| Physics Operator Comments | |||
| May 16 2008 09:16:27:807AM | 1080516001 | Ron Parker | First shot OK |
| May 16 2008 09:32:15:020AM | 1080516002 | Ron Parker | Shot 2 was fine |
| May 16 2008 09:31:09:173AM | 1080516003 | Ron Parker | Shot 3 ran OK |
| May 16 2008 09:53:15:960AM | 1080516004 | Ron Parker | Shot 4 ran, but disrupted shortly after J-port was powered. |
| May 16 2008 09:58:44:587AM | 1080516005 | Ron Parker | Shot 5 was "really good" according to Catherine. |
| May 16 2008 10:11:17:737AM | 1080516006 | Ron Parker | Oh, oh. Early disruption. |
| May 16 2008 10:46:54:920AM | 1080516007 | Ron Parker | Shot 7 disrupted early |
| May 16 2008 10:46:36:610AM | 1080516008 | Ron Parker | shot 8 was better, but also disrupted, this time at 1.37 s. |
| May 16 2008 10:48:55:517AM | 1080516009 | Ron Parker | Shot 9 was similar to shot 8, disrupting around 1.4 s. |
| May 16 2008 11:34:54:443AM | 1080516010 | Ron Parker | Intermittent ITB's, no J port |
| May 16 2008 11:35:52:693AM | 1080516011 | Ron Parker | Finally, success! Similar to shot 5 |
| May 16 2008 11:40:46:010AM | 1080516012 | Ron Parker | Now on Chuck's run plan. Shot 12 disrupted |
| May 16 2008 11:47:48:903AM | 1080516013 | Ron Parker | Early disruption |
| May 16 2008 12:10:15:440PM | 1080516014 | Ron Parker | Shot 14 disrupted early again. We'll load entire shot from 21080221009 |
| May 16 2008 12:15:22:600PM | 1080516015 | Ron Parker | This was a no power shot, because PO thought pulse gas was not set for cryopump. Actually, the programmed shot had cryo on. |
| May 16 2008 12:36:25:397PM | 1080516016 | Ron Parker | Shot 16 ran, density a bit low. Next: density set 6e19 m-2, faster ip ramp. |
| May 16 2008 12:50:01:513PM | 1080516017 | Ron Parker | Shot 17 ran well, as programmed. Locked modes are troublesome. |
| May 16 2008 12:56:18:660PM | 1080516018 | Ron Parker | Shot 18 ran, fairly good sot with H-modes. |
| May 16 2008 01:17:21:410PM | 1080516019 | Ron Parker | Earl Marmar taking over as physop for 1 hour.
Increase prefill 4 msec (now 59 msec) Try to get to nl_04 target a bit sooner Plasma 2 low density H-modes, with quite peaked density profiles |
| May 16 2008 01:32:20:690PM | 1080516020 | Ron Parker | no dpcs changes
plasma startup is bouncing pretty hard to the outside at 23 msec |
| May 16 2008 01:46:01:793PM | 1080516021 | Ron Parker | add 4 msec to prefill puff
plasma startup looks a bit smoother long-lived ITB with on axis (.5 MW) and off-axis (2 MW) ICRF When LH comes on, density peaking decreases |
| May 16 2008 01:54:38:313PM | 1080516022 | Ron Parker | no dpcs changes
plasma early disruption (0.19 seconds) looks something large fell in, radiated power spikes to 5 MW |
| May 16 2008 02:10:25:640PM | 1080516023 | Ron Parker | no dpcs changes
plasma |
| May 16 2008 02:21:29:193PM | 1080516024 | Ron Parker | Shot 24 ran OK. Parker back, expect trouble. |
| May 16 2008 02:51:55:703PM | 1080516025 | Ron Parker | Shot 25 was OK. |
| May 16 2008 02:58:23:817PM | 1080516026 | Ron Parker | Shot 26 was OK
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| May 16 2008 03:07:34:183PM | 1080516027 | Ron Parker | Disruption |
| May 16 2008 03:25:52:153PM | 1080516028 | Ron Parker | Shot ran, disrupted around 1.25 s. Pretty ratty discharge. |
| May 16 2008 03:36:16:673PM | 1080516028 | Ron Parker | Density at grill is too high for LH coupling. Increased outer gap by 1 cm to try to improve coupling. |
| May 16 2008 03:44:47:100PM | 1080516029 | Ron Parker | another disruption, this one at 0.6 s. |
| May 16 2008 04:04:34:053PM | 1080516030 | Ron Parker | Shot 30 ran, but disrupted at 1.27 s. |
| May 16 2008 04:35:13:983PM | 1080516031 | Ron Parker | Shot 31 had an early disruption.
Short delay due to cooling problem. |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 09:02:50:293AM | Plasma | Ok | |
| 2 | 09:16:30:867AM | Plasma | Ok | |
| 3 | 09:28:59:440AM | Plasma | Ok | |
| 4 | 09:41:22:917AM | Plasma | Ok | |
| 5 | 09:54:27:613AM | Plasma | Ok | |
| 6 | 10:06:53:297AM | Plasma | Ok | |
| 7 | 10:19:16:650AM | Plasma | Ok | |
| 8 | 10:32:59:207AM | Plasma | Ok | |
| 9 | 10:45:28:967AM | Plasma | Ok | |
| 10 | 10:58:02:133AM | Plasma | Ok | |
| 11 | 11:10:37:250AM | Plasma | Ok | |
| 12 | 11:32:52:783AM | Plasma | Ok | |
| 13 | 11:45:14:967AM | Plasma | Ok | |
| 14 | 11:59:41:553AM | Plasma | Ok | |
| 15 | 12:12:09:830PM | Plasma | Bad | No power shot requested by PO |
| 16 | 12:25:11:043PM | Plasma | Ok | |
| 17 | 12:39:28:430PM | Plasma | Ok | |
| 18 | 12:53:04:923PM | Plasma | Ok | |
| 19 | 01:06:29:107PM | Plasma | Ok | |
| 20 | 01:23:00:073PM | Plasma | Ok | |
| 21 | 01:36:05:660PM | Plasma | Ok | |
| 22 | 01:48:50:577PM | Plasma | Ok | |
| 23 | 02:01:50:273PM | Plasma | Ok | |
| 24 | 02:15:33:550PM | Plasma | Ok | |
| 25 | 02:35:49:190PM | Plasma | Ok | |
| 26 | 02:49:48:937PM | Plasma | Ok | |
| 27 | 03:05:08:040PM | Plasma | Ok | |
| 28 | 03:17:41:437PM | Plasma | Ok | |
| 29 | 03:39:45:660PM | Plasma | Ok | |
| 30 | 03:57:30:890PM | Plasma | Ok | |
| 31 | 04:11:30:293PM | Plasma | Ok | |
| 32 | 04:55:45:000PM | Plasma | Ok | |
| System Availability | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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