Miniproposals

Miniproposal: Date Filed: Title: First Author: Session Leader: Steve Golovato (shots 1-31) Session Leader: Jim Terry (shots 1-31)

Engineering Operator Run Comment

icrf

Session Leader Plans

Physics Operators Plans

Session Leader Summaries

Entered: Jul 7 2004 03:49:11:803PM

Author: To Be Determined

run summary - 950112 --------------------- SL: golovato (terry in piggyback) PO: marmar EO: bertolino/daigle Goals- (1) Establish plasma with sufficiently high loading to get to high power on E-port antenna, which requires that the peak voltage be kept below about 40 kv. Loading above 5 Ohms necessary, while closer to 10 Ohms would be desirable. The plasma will be diverted but raised about 1cm to get a better match to the antenna shape, with outer gap of about 1 cm, and line density of 1-1.5e20 m-2. (2) Raise power to highest level possible, achieving good pulses at or above 1.5 MW, satisfying mini-proposal 54, conditioning of the E-port antenna (3) Compare heating performance of E-port antenna with previous results using D-port antenna. Set-up - Running E-port antenna from transmitter #1 using D-port tuners, i. e., D-port transmitter, transmission line and tuners, E-port resonant loops and antenna. The piggyback run involved puffing of xenon and various laser blow-offs, which will be summarized by Jim Terry at the end of this session-leader summary. This was a very successful run from the rf standpoint. We ran diverted plasmas with high density, nl04 programmed to 1.2e20, and small outer gap, 0.6-0.8 cm. We spent the first 10 shots getting the plasma configuration we wanted and fixing the startup (see physics operator summary), although shots 2 and 10 already got 1,5 MW onto the E-port antenna for a short time. We got good tuning at shot 13. The loading was about 5 Ohms for these plasmas, which tranlated into 41 kV at 2 MW. We got to 1.75 MW on shot 19 where we began hitting the power limit for the transmitter at its current cavity tuning. We programmed a square rf pulse from .6-.9 se on shot 22 as a clean heating demonstration at about 1.6 MW. We got delta(Te)>1 keV, delta(Ti)=0.65 keV and delta(Wp)=24-27 kJ. This is very comparable to the performance of the D-port antenna at higher density, see for example shot 940622006. With this shot, we can declare mini-proposal 54 successfully completed. We then concentrated on combining ICRF with Li pellet injection by firing a pellet just before rf turn-on to avoid tripping the rf at the initial large density spike. We had a Li pellet and rf after 1 sec on shot 12 and noticed that the heating appeared quite strong even at lowish power. Unexpectedly, but to the delight of Joe Snipes, we got a short H-mode on shot 23. We got similar H-modes on shots 27 and 30. The rf ran with a peak voltage of 44 kV on the tuners on shot 27. Shot 28 was another good non H-mode heating shot. Shots 28, 30, and 31 had medium pellets, the rest were small pellets. Shot 31 was a good example of the possible enhanced heating (confinement) during the Li pellet phase. We saw the largest increase in stored energy we've seen, 40 kJ on the diamagnetic signal and the highest neutron rate we've seen as well. Darren Garnier got good data on the cigar detector which showed the Li cloud to be shorter than expected, more football than cigar shaped. The session leader shot-to-shot summary can be found in the logbook under the session_leader topic. Details on technical difficulties can be found in the physics operator summary. The magnetics data was bad on shot 28 so there's no EFIT output and there was no rf on shot 25 because of a camac problem. The shot summary was: 23 plasmas (3 disrupted very early) 7 fizzles 1 dud (ef4 problem) Thie following summary concerns that part of the 950112 run which relates to MP #072 "Observation magnetic dipole radiation from W+52 at about 3900 A in the Ti I isoelectronic sequence". There were 4 major goals of this MP: 1) Learn how to puff Xe into C-Mod and diagnose it; 2) Observe the M1 (forbidden) line of Ti-like Xe at 4139 A; 3) Inject W into C-Mod and diagnose it; 4) Measure the radiation properties of Xe and W in the main plasma. Essentially we successfully puffed Xe (#1) and we successfully measured the radiated power for Xe and W (#4). However were only partially successful in injecting W (the plasma disrupted), and we did NOT observe the forbidden line in Ti-like Xe. The shot summary is: Shot # Xe puff Xe puff Plenum Press. Pulse width Xe+24 into RF into ohmic (psia) (ms) emission (time) (time) (x10^15 ph/s/cm^2/st) 950112013 X (0.8) 5.36 10 5.5(disrupted) 950112014 no Xe not detectable 950112015 no Xe not detectable 950112016 no Xe not detectable 950112018 X (0.8) 2 5 0.17 950112019 X (0.8) 2 8 0.7 950112020 X (0.8) 2 8 0.8 950112021 X (0.75) 2 6 <0.15 950112022 X (0.75) 2 10 0.6 950112023 X (0.75) 2 13 1.0 950112024 X (0.75) 2 17 2.9(disrupted) 950112025 X (0.75) 2 13 2.8 950112026 X (0.75) 2 10 1.9 950112027 X (0.75) 2 10 ? 950112028 X (0.75) 2 10 ? 950112029 Tungsten injection at 0.7 s which disrupted the plasma 950112030 no Xe, no W 950112031 no Xe, no W Other observations: Divertor detachment due to Xe was observed for shots 024, 025, 026. Radiated power from the main plasma was 90-100% of input power after the Xenon puff for shots 024, 025, and 026. Radiated power from the main plasma after the W injection was > 100% of the input power. Comparing shots 950112023 and 950112025, it is implied that the Xe penetration is reduced by a factor of ~3 when Xe is puffed into an RF heated discharge. (This is also seen comparing shots 950112022 and 950112026.)

Physics Operator Summaries

Entered: Jul 7 2004 04:36:52:863PM

Author: To Be Determined

From: ZENITH::MARMAR Date: 12-JAN-1995 21:42:33 Description: Physics Operator Summary: 950112 FROM: PHYSOP::MARMAR Date: 12-JAN-1995 19:09:31 Description: Physics operator summary: 950112 Summary of run 950112 E.O. Bertolino/Daigle S.L. Golovato P.O. Marmar RF Heating run Piggy Back: Xenon/Tungsten search for forbidden line After a slow start, this was a productive run. Early fizzle problems appeared to be solved by a tweak to the OH1 voltage programming between 5 and 15 msec, starting with shot 7. We lost the D-E BP coil #12 for shot 14, which caused the plasma to ride out by about 1.5 cm, limited on the outer protection limiters. From shot 15 on, the J-K coil was used instead. The predictors were recalculated for shot 17. The E port antenna was brought up to 1.6 MW for .3 second pulse lengths. See the session leader summary for details. Short ELM-free H-modes were observed on some shots which had lithium pellet injection. We rediscovered that after the TF goes into inversion, the EF3 supply misbehaves. For the moment, the workaround is to move the TF inversion time out late (1.4 seconds). ECDC in D2 was run for about 2 hours before the run. Shot summary: 1: Start from 950110032; increase nel_04; move RCUR out, ZCUR up, ZXL up, increase Clearin, Ip to .86MA; fill = 1.4e-5; TF invert to 1.2 s fizzle 2: Fill=1.6e-5; plasma 3: no change; fizzle 4: decrease clearin, fill=1.8e-5 fizzle 5: fill=1.5e-5 fizzle 6: fill=2.0e-5 fizzle 7: call in the wireheads; lower OH1 programmed voltage by 50 V between 5 and 15 msec; plasma 8: repeat; disrupt at 1.2 9: lower nel4 target late; fizzle 10: lower Ip to .8MA, fill = 1.6e-5; plasma 11: nel4 to 1.2e20; plasma 12: lengthen ne flattop; Li pellet at 1.0s; plasma 13: Ar + Xe; disrupt due to Xe at .875 s; 1.2 MW RF plasma 14: Xe off; 1.4e-5; disrupt; plasma ran too far outside; bad BP coil 15: lower Ar; change fast ZCUR prop gain after 1 s; replace BP coil in feedback; fizzle 16: repeat; plasma 17: Xe back on (less); predictors recalculated; dud; no EF4 18: fill 1.5e-5; plasma 19: more Xe; Sc injection; Li pellet at 0.9s; plasma 20: more Ar; Li; Sc; 1.6 MW RF; plasma 21: Xe 50 ms earlier; Li; 1.6 MW; plasma 22: Twiddle Ip rampdown; more Xe; plasma 23: More Xe; Li; plasma 24: More Xe; disrupt; no pellet; plasma 25: fill=1.4e-5; disrupt; too much Xe; plasma 26: lower Xe; slow down Ip rampdown; plasma 27: add deriv gain to nel4; RF H-mode after Li pellet; plasma 28: Increase gains on late ZXL, ZXU; add gas early; big Li pellet; plasma 29: TF invert to 1.4 s; increase early gas; W injection at .7s; disrupt ; plasma 30: No W; rampdown improved; RF H-Mode post pellet; plasma 31: TF invert to 1.6 s; disrupt on rampdown at .27 MA, 1.47 second; plasma Suggestion for tomorrow: start from 950112031, but increase rate of Ip rampdown. Also note that the outer gap was purposely set to be very small for the RF, at about 0.7 cm. Loading of any shot prior to 950112017 will bring in the predictors calculated for the wrong BP12 coil. 1 PS dud; 7 fizzles; 23 plasmas

Session Leader Comments
Jan 12 1995 10:08:17:150AM		Steve Golovato	run 950112 - Goals (1) Establish plasma with sufficiently high loading to get to high power on E-port antenna, which requires that the peak voltage be kept below about 40 kv. Loading above 5 Ohms necessary, while closer to 10 Ohms would be desirable. The plasma will be diverted but raised about 1cm to get a better match to the antenna shape, with outer gap of about 1 cm, and line density of 1-1.5e20 m-2. (2) Raise power to highest level possible, achieving good pulses at above 1.5 MW. (3) Compare heating performance of E-port antenna with previous results using D-port antenna. Set-up - Running E-port antenna from transmitter #1 using D-port tuners, i. e., D-port transmitter, transmission line and tuners, E-port resonant loops and antenna.
Jan 12 1995 10:08:50:330AM	950112001	Steve Golovato	shot 950112001 - fizzle.
Jan 12 1995 10:10:08:630AM	950112002	Steve Golovato	shot 950112002 - good shot, nl04=8.e19, loading low, 3 down to 1.5 ohms. get about 1.5 mw at 45 kv. rf interrupting.
Jan 12 1995 10:10:43:210AM	950112002	Steve Golovato	shot 950112002 - outer gap 1.5cm.
Jan 12 1995 10:11:20:080AM	950112003	Steve Golovato	shot 950112003 - fizzle.
Jan 12 1995 10:11:51:270AM	950112004	Steve Golovato	shot 950112004 - fizzle.
Jan 12 1995 10:12:09:610AM	950112005	Steve Golovato	shot 950112005 - fizzle.
Jan 12 1995 10:12:29:220AM	950112006	Steve Golovato	shot 950112006 - fizzle.
Jan 12 1995 10:19:18:890AM	950112007	Steve Golovato	shot 950112007 - good shot. nl04=1.e20. outer gap=0.7cm. loading higher, about 4-5 ohms, power low, interrupting, not clear why.
Jan 12 1995 10:30:10:380AM	950112008	Steve Golovato	shot 950112008 - good shot. same as last shot. no rf data due to triggering mix-up (mike fired a test shot during init).
Jan 12 1995 10:47:42:110AM	950112009	Steve Golovato	shot 950112009 - fizzle.
Jan 12 1995 11:05:40:860AM	950112010	Steve Golovato	shot 950112010 - good shot.1.5MW, 38KV, loading 4-5ohms. arced. need more lasding, raise nl04 to 1.2e20 from 1.e20 for next shot. outer gap 0.85. Heating observable on ece, Wp, neutrons.
Jan 12 1995 11:15:36:970AM	950112011	Steve Golovato	shot 950112011 - good shot. nl04=1.15e20 but programmed down starting at 700ms. needs to be extended. tune not good, power low.
Jan 12 1995 11:27:42:590AM	950112012	Steve Golovato	shot 950112012 - good shot. rf interrupting but got loading data during nl04=1.2e20, about 8-9 ohms. we'll tune to this plasma. small lithium pellet shot in at 1 sec. adding argon and xenon gas pulses for next shot at 0.3 and 0.8 sec respectively.
Jan 12 1995 11:44:48:570AM	950112012	Steve Golovato	shot 950112012 - rf ran during Li pellet after 1.sec, with high density, peaked profile. heating looks strong, 400kW gives delta(Wp_efit) of 25kJ, comparable to Prf>1.5MW with typical plasma.
Jan 12 1995 11:40:36:560AM	950112013	Steve Golovato	shot 950112013 - good shot. no lithium pellet. disrupted at 870ms, probably because of xenon puff at 800ms. rf weel tuned at this density. 1.2MW, 31KV., loading about 5.5-6 ohms at high power.
Jan 12 1995 11:58:54:000AM	950112014	Steve Golovato	shot 950112014 - good shot. disrupted at 1.03ms, no Li pellet. rf didn't run at high power, low power loading at 850ms is about 11 ohms. we saw large glow on limiter, lost limiter probe. it may be that when there's a strong interaction at the limiter, causing blowoff, it effects antenna operation. from the antenna standpoint, this shot should have been identical to the last shot.
Jan 12 1995 12:04:22:250PM	950112014	Steve Golovato	shot 950112014 - between shots 14 and 15, there was cell access to fix OMA for xenon piggyback experiment (because the rf group are such nice guys). also there was no xenon pulse on shot 14, we'll lower the plenum pressure to reduce the puff, hopefully avoiding disruptions.
Jan 12 1995 12:06:56:230PM	950112014	Steve Golovato	shot 950112014 - cause of problems on this shot, plasma ran on outer limiter (outer gap = 0cm) for this shot.
Jan 12 1995 12:43:01:830PM	950112014	Steve Golovato	shot 950112014 - plasma ran 2 cm too far out, against outer limiter because of bad bp coil. we had a second cell access for horne to switch another bp coil (from another poloidal location) into the hybrid.
Jan 12 1995 12:52:01:890PM	950112015	Steve Golovato	shot 950112015 - there was about an hour between shots 14 and 15. fizzle. may be because we didn't recalculate the predictors taking into account the new coil. this will be done for the next shot. it had been assumed that the coils were close enough to identical that this wasn't necessary.
Jan 12 1995 01:09:33:790PM	950112016	Steve Golovato	shot 950112016 - good shot. 1.35MW, 34 KV. loading 5 ohms, 7 ohms at low power. no rf interrupts, clean shot. outer gap 0.5 cm. delta(Wp)=17 kJ, delta(Te_0)= 1keV.
Jan 12 1995 01:14:39:200PM	950112017	Steve Golovato	shot 950112017 - dud. ef4 problem.
Jan 12 1995 01:39:59:600PM	950112018	Steve Golovato	shot 950112018 - xenon puff back on. good shot. 1.4MW and 1.2 MW pulses. Li pellet at 1 sec. good heating.
Jan 12 1995 01:42:23:980PM	950112019	Steve Golovato	shot 950112019- move Li pellet to 900ms, during second rf pulse. outer gap .6-.8cm
Jan 12 1995 01:57:33:240PM	950112019	Steve Golovato	shot 950112019- good shot. 1.75 MW, transmitter tripped out. had 38 kV 1.6 MW and 4.5 ohms loading. at .72-.73sec, get what looks like an H-mode but there was a big moly event at that time and the loading went up rather than down 4.5 to 8 ohms). also the store denergy went down, not up. the transmitter tripped at .76sec.
Jan 12 1995 02:13:28:580PM	950112020	Steve Golovato	shot 950112020- good shot. rf trips rigth after Li pellet at 900 ms. see change in loading, interrupts after xenon puff. there was a moly event at this time as well and the loading increased as it did last shot. last shot it was earlier and didn't correlate with the xenon puff. there was also a scandium injection at .5 sec (unbeknownst to me).
Jan 12 1995 02:25:24:820PM	950112021	Steve Golovato	shot 950112021- xenon puff moved to 750ms, rf power lowered during Li pellet. transmitter tripped again. 1.7MW. also some interrupts.
Jan 12 1995 02:46:47:470PM	950112022	Steve Golovato	shot 950112022- look for clean heating shot, lower power, pulse from .6-.9ms, no Li pellet. good shot. delta(Wp)=24-27kJ. delta(te)=1.25keV. delta(Ti)=0.65keV.
Jan 12 1995 03:03:46:450PM	950112023	Steve Golovato	shot 950112023- Li pellet just before rf pulse, so it doesn't cause rf interrupt. good shot. H-mode at .63 ms for about 20 ms, rf loading drops to 2 ohms, Vmax=45kV. Prf about 1.5 MW, drops to 1.2MW in H-mode. H-mode lost during rf interrupt, does not come back when rf comes back on.
Jan 12 1995 03:30:15:210PM	950112024	Steve Golovato	shot 950112024 - retry some shot. shot died at 850ms, probably because of increased xenon puff at 750ms. no Li pellet, rf tranmitter tripped at 670ms. no H-mode.
Jan 12 1995 03:43:16:490PM	950112025	Steve Golovato	shot 950112025 - lower xenon puff. disrupted at 1.1sec. no rf.
Jan 12 1995 03:49:31:610PM	950112026	Steve Golovato	shot 950112026 - good shot, no Li pellet, rf interrupted throughout. tuning chnaged after h-mode shot, changed back for next shot.
Jan 12 1995 04:29:36:630PM	950112027	Steve Golovato	shot 950112027 - good shot. rf ran without interrupt up to 44kV. got another H-mode with the Li-pellet. short lived, 24ms. this is with small pellet, try medium pellet next shot.
Jan 12 1995 04:38:00:610PM	950112028	Steve Golovato	shot 950112028 - good shot. no H-mode with big Li pellet but good rf heating.
Jan 12 1995 04:57:06:640PM	950112029	Steve Golovato	shot 950112029 - good shot until tungsten injection at 700ms, when it disrupted.
Jan 12 1995 05:06:07:220PM	950112030	Steve Golovato	shot 950112030 - good shot. rf interrupts starting at 750ms. got H-mode at 715ms, lasted 17ms. loading drops from 3 to 2 ms. mis-tuned late in shot because density is too low.
Jan 12 1995 05:25:13:670PM	950112031	Steve Golovato	shot 950112031 - same as last shot but rf power reduced slightly. no H-mode, one rf interrupt right at what looks like an attempt at an H-mode transition. Heating particularly strong during Li-pellet decay, get largest delta(Wp) e've seen, up to 40kJ on the diamagnetic signal.

Physics Operator Comments
Jan 12 1995 11:26:38:190AM	950112012	Jim Terry	Setting up for Xe puff thru the B side upper valve. The plenum pressure is 5.36 psia. The valve is setup at 100V for 10 ms at 0.8 s.
Jan 12 1995 01:05:10:210PM	950112013	Jim Terry	Puffed Xe for the 1st time, Saw Xe in a big way on MM and the VUV. 100% radiated power. then disrupted.
Jan 12 1995 01:07:20:880PM	950112014	Jim Terry	No Xe puffed on this shot. No Xe seen by VUV. Implies that the Xe pumps out very well.
Jan 12 1995 01:27:54:240PM	950112017	Jim Terry	Xe puffed on this shot with pulse set up as - 2 psig, 5 ms open at 0.8 sec.
Jan 12 1995 01:35:03:060PM	950112018	Jim Terry	Xe puffed on this shot with pulse set up as - 2 psig, 5 ms open at 0.8 sec. Nothing seen on VUV.
Jan 12 1995 01:56:37:310PM	950112019	Jim Terry	Xe puffed on this shot with pulse set up as - 2 psig, 8 ms open at 0.8 sec. Seen on VUV and bolos. Not overwhelming though.
Jan 12 1995 01:59:30:590PM	950112019	Jim Terry	Sc injection at 0.55 s. Not very big.
Jan 12 1995 02:11:51:950PM	950112020	Jim Terry	Sc injection at 0.55 s. Not very big.
Jan 12 1995 02:31:35:940PM	950112020	Jim Terry	Xe puffed at 0.8 s
Jan 12 1995 02:20:13:400PM	950112021	Jim Terry	Sc injection at 0.55 s. Not very big.
Jan 12 1995 02:32:50:470PM	950112021	Jim Terry	Xe puffed at 0.75 s but pulse to valve was very narrow. Nothing seen on VUV.
Jan 12 1995 02:50:22:780PM	950112022	Jim Terry	Xe puffed at 0.75 s , pulse to valve set to 10 ms. Seen on bolo and VUV Sc injection at 0.35 s (i.e. before diversion)
Jan 12 1995 03:28:34:750PM	950112023	Jim Terry	Xe puffed at 0.75 s , pulse to valve set to 13 ms. Seen on bolo and VUV.
Jan 12 1995 03:27:31:970PM	950112024	Jim Terry	Xe puffed at 0.75 s , pulse to valve set to 16 ms. Seen on bolo and VUV. Too much Xe, no RF at puff time, disrupted.
Jan 12 1995 03:35:40:710PM	950112025	Jim Terry	Xe puffed at 0.75 s , pulse to valve set back to 10 ms. Lots een on bolo and VUV.
Jan 12 1995 03:56:19:060PM	950112026	Jim Terry	Xe puffed at 0.75 s , pulse to valve set back to 9 ms. Seen on bolo and VUV.
Jan 12 1995 04:11:07:990PM	950112027	Jim Terry	Xe puffed at 0.75 s , pulse to valve at 9 ms.
Jan 12 1995 04:42:22:530PM	950112029	Jim Terry	Tungsten injection at .7 s. Disrupted the plasma.
Jan 12 1995 05:09:38:860PM	950112030	Jim Terry	No Xe puff and no W injection

Engineering Operator Comments
Shot	Time	Type	Status	Comment
1	08:45:55:650AM	Plasma	Ok	no faults
2	08:58:04:460AM	Plasma	Ok	oh1 comm fault after disruption
3	09:13:58:330AM	Plasma	Ok	no faults
4	09:25:51:550AM	Plasma	Ok	no faults
5	09:36:15:570AM	Plasma	Ok	no faults
6	09:45:59:040AM	Plasma	Ok	no faults
7	10:06:55:210AM	Plasma	Ok	no faults
8	10:20:39:360AM	Plasma	Ok	no faults
9	10:39:43:180AM	Plasma	Ok	no faults
10	10:52:02:560AM	Plasma	Ok	no faults
11	11:03:30:230AM	Plasma	Ok	no faults
12	11:17:34:030AM	Plasma	Ok	no faults
13	11:29:27:390AM	Plasma	Ok	no faults
14	11:43:54:190AM	Plasma	Ok	no faults
15	12:42:31:310PM	Plasma	Ok	No faults.
16	12:55:21:510PM	Plasma	Ok	No faults
17	01:08:50:350PM	Plasma	Ok	No Faults.
18	01:22:55:230PM	Plasma	Ok	No Faults.
19	01:41:33:950PM	Plasma	Ok	no faults
20	01:55:57:990PM	Plasma	Ok	No faults.
21	02:12:44:450PM	Plasma	Ok	No Faults.
22	02:29:51:300PM	Plasma	Ok	No faults.
23	02:46:32:190PM	Plasma	Ok	No Faults.
24	03:03:19:830PM	Plasma	Ok	No Faults.
25	03:21:46:110PM	Plasma	Ok	No Faults.
26	03:41:13:170PM	Plasma	Ok	Comm Fault OH1
27	03:56:23:080PM	Plasma	Ok	No Faults.
28	04:16:09:890PM	Plasma	Ok	No Faults,
29	04:34:17:890PM	Plasma	Ok	No Faults
30	04:53:31:400PM	Plasma	Ok	No Faults.
31	05:09:04:170PM	Plasma	Ok	No Faults