Alcator C-Mod Run 1040409 Information

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Miniproposals
Miniproposal:375
Date Filed:11/25/2003
Title:Rotation and H-mode Threshold vs. SSEP
First Author:John Rice
Session Leader:John Rice (shots 1-30)

Operators
Session leader(s):John Rice
Physics operator(s):Dmitri Mossessian
Engineering operator(s):Gary Dekow

Engineering Operator Run Comment
MP#375 H-mode threshold and SSEP; SL:Rice; PO:Mossessian; EO:Dekow/Fitz/

Session Leader Plans

Physics Operators Plans

Session Leader Summaries
Entered: Jul 7 2004 03:49:04:647PM
Author: John Rice

Session Leader Run Summary for 1040409 MP375 Rotation and H-mode Threshold vs SSEP

This run went extremely well, with good H-mode power threshold data for SSEP values
between -1.3 and +1.7. The usual very strong dependence of the ambient L-mode rotation
on SSEP in near double null was seen. There was a good correlation between the rotation
velocity in L-mode and the ICRF power needed to induce the H-mode, as the power threshold
was also a very strong function of SSEP near double null.

SSEP VTor P for H-mode

-1.2 ~0 1.1 MW
-0.3 -5 km/s 1.1 MW
0 -20 km/s 1.4 MW
+0.4 -45 km/s 3.4 MW
+0.5 -25 km/s 2.8 MW
+1.7 -30 km/s 3.0 MW

Physics Operator Summaries
Entered: Jul 7 2004 04:36:49:833PM
Author: Dmitri Mossessian
Physop summary for 1040409 - MP#375 H-mode threshold and SSEP

Session leader: Rice
Physics operator: Mossessian

Setup:

Overnight ECDC in D2 at 2e-4 Torr

Run begins at 09:00 and ends at 17:00.

Power systems the same as 1040220001

A-coils should be enabled in the standard configuration.

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 was is Hybrid disabled (PG2)
fill C-side with 40 psi D2 Hybrid enabled (PG3)


Enable the following gatevalves: ECE, VUV, DNB

Run plan:

Start with 1040220001. Run segment 4 - SSEP control.
Scan SSEP from LN to UP through DN and establish H-mode threshold dependance on SSEP.
-

Summary:

Despite quite a few problems substantial number of useful shots was produced.
For the first shot we used startup from yesterday, when Br had to be offset -1 mT
to avoid fizzles. This startup produced the only fizzle. After adjusting Br and Bz to more
reasonable values startup was good to the end of the day.
Segment 4 was used for SSEP control. After shot 13 CLEARIN was changed to reference
to upper x-point to allow for larger positive SSEP (see details below). This was changed back
on shot 25.
From shot 9 on almost every shot terminated in a disruption due to massive injection
of unknown origin.
Then on shot 20 EF4 supply fuse burned and some time was pent replacing it and running
tests.
Shots 22 and 29 had TCI feedback problems, and shot 30 was run without density feedback
with nl04 wire turned off.
Shot 24 did not have startup due to Hybrid problems.



1040409001 Fizzle. Both Br and Bz look too negative.

Next shot: Br offset -1 mT -> 0 mT, Bz up by moving IC_EF4U -1345 -> -1330.
----------------------------------------------------------------------------
1040409002 Plasma. Good startup. SSEP=-0.4

Next shot: nl up 8e19 -> 8.5e19
----------------------------------------------------------------------------
1040409003 Plasma.

Next shot: no changes
----------------------------------------------------------------------------
1040409004 Plasma.

Next shot: SSEP 3 mm up to -0.1 cm
----------------------------------------------------------------------------
1040409005 Plasma. Nice DN with SSEP around 0

Next shot: no change
----------------------------------------------------------------------------
1040409006 Plasma.

Next shot: no change
----------------------------------------------------------------------------
1040409007 Plasma.

Next shot: RCUR up 2 mm at 0.8 sec to make right gap steadier. SSEP up 3 mm.
----------------------------------------------------------------------------
1040409008 Plasma. Upper null - SSEP around 0.3. Right gap = 2.2 cm const.

Next shot: RCUR up 3 mm to decrease right gap to ~ 1.5 cm
----------------------------------------------------------------------------
1040409009 Plasma. Disrupted at 0.93 sec due to injection

Next shot: no change
----------------------------------------------------------------------------
1040409010 Plasma. Steady righ gap around 1.7 cm

Next shot: no change
----------------------------------------------------------------------------
1040409012 Plasma.

Next shot: TF 149000 -> 148440 to drop Bt 0.02 T at Amanda's request
----------------------------------------------------------------------------
1040409013 Plasma.

Next shot: To increase SSEP more and keep control over CLEARIN load CLEARIN wire
from shot 1040220001 segment 3 (UN) where its controller is referenced to upper
x-point.
Load wire 4, seg 3, 1040220001 into wire 4, seg 4
Load wire 1, seg 3, 1040220001 into wire 1, seg 4 (RCUR)
SSEP up 3 mm
----------------------------------------------------------------------------
1040409014 Plasma. Right and left gaps around 1 cm, SSEP around 6 mm.

Next shot: no change
----------------------------------------------------------------------------
1040409015 Plasma. Disrupted at 1.62 due to injection

Next shot: SSEP up to 2 cm
----------------------------------------------------------------------------
1040409016 Plasma. Ran fine, but the shape is out of control since the demand for
SSEP exceeds allowable bounds.

Next shot: Reload segment4 from shot 15. Load segment 3 from 1040220001, adjusted nl and TF.
Run segment 3 for UN
----------------------------------------------------------------------------
1040409018 Plasma. Disrupted at 1.6 sec due to injection.

Next shot: nl up to 9e19
----------------------------------------------------------------------------
1040409019 Plasma. Disrupted at 1.3 sec due to injection.

Next shot: nl up to 9.5e19. RXU 5 mm more positive to move upper strike point and
avoid disruptions
----------------------------------------------------------------------------
1040409020 Plasma. Disrupted at .3 sec due to injection.

Next shot: adjusted RXU again to move out later.
----------------------------------------------------------------------------
1040409020 Slight delay - EF4 fuse needs to be replaced.
----------------------------------------------------------------------------
1040409022 Plasma. Disrupted early - problems with TCI led to lost feedback
and uncontrolled rise of ne.

Next shot: no PCS changes.
----------------------------------------------------------------------------
1040409023 Plasma.

Next shot: Go to segment 4 again. SSEP -> -1 cm for LN
----------------------------------------------------------------------------
1040409024 Dud. Hybrid problems.

Next shot: no power test
----------------------------------------------------------------------------
1040409027 Plasma. Disrupted at 1.4 sec due to injection

Next shot: no PCS change
----------------------------------------------------------------------------
1040409028 Plasma.

Next shot: SSEP to +1.5 mm
----------------------------------------------------------------------------
1040409029 Plasma. TCI feedback is not working, we got nl~5e19

Next shot: turn off nl feedback (set gains on nl to 0 in seg. 4). Paste gas trace from shot 27 into
PG3 program. SSEP down 1 mm

----------------------------------------------------------------------------
1040409030 Plasma. Good density trace

-


Session Leader Comments
Apr 9 2004 09:41:13:987AM1040409002John RiceSSEP -.37, RF ~2, H-mode
Apr 9 2004 09:41:32:300AM1040409003John RiceSSEP -.35, RF 1.17, H-mode
Apr 9 2004 09:53:28:143AM1040409004John RiceSSEP -.38, RF 1.04, L-mode
Apr 9 2004 10:06:08:210AM1040409005John RiceSSEP -.02, RF 0.82, L-mode
Apr 9 2004 10:29:51:870AM1040409006John RiceSSEP +.02, RF 1.32, L-mode 1.5 RF, H-mode
Apr 9 2004 10:42:00:610AM1040409006John RiceSSEP -.03, RF 1.51, H-mode
Apr 9 2004 10:47:22:960AM1040409006John RiceSSEP +.02, RF 1.32, L-mode, RF 1.5 H-mode
Apr 9 2004 10:46:49:647AM1040409007John RiceSSEP -.03, RF 1.51, H-mode
Apr 9 2004 10:54:12:017AM1040409008John RiceSSEP +.33, RF 1.38, L-mode RF 3.6, H-mode
Apr 9 2004 11:08:01:023AM1040409009John RiceSSEP +.33, RF 1.97, L-mode
Apr 9 2004 11:23:03:423AM1040409010John RiceSSEP +.37, RF 2.10, L-mode
Apr 9 2004 11:37:46:973AM1040409011John RiceSSEP +.39, RF 2.94, L-mode
Apr 9 2004 11:52:35:560AM1040409012John RiceSSEP +.41, RF 3.25, L-mode
Apr 9 2004 12:10:56:603PM1040409013John RiceSSEP +.38, RF 3.50, H-mode
Apr 9 2004 12:30:05:743PM1040409014John RiceSSEP +.52, RF 3.36, H-mode
Apr 9 2004 12:40:37:633PM1040409015John RiceSSEP +.44, RF 3.01, H-mode
Apr 9 2004 12:56:05:753PM1040409016John RiceSSEP +.62, RF 3.01, H-mode
Apr 9 2004 01:09:43:617PM1040409017John RiceUSN, RF 3.16, H-mode
Apr 9 2004 01:22:55:387PM1040409018John RiceUSN, RF 2.88, H-mode
Apr 9 2004 01:36:04:297PM1040409019John RiceUSN, RF 2.80, H-mode
Apr 9 2004 03:32:43:523PM1040409023John RiceUSN, RF 2.65, L-mode
Apr 9 2004 04:11:47:617PM1040409026John RiceLSN, RF 0, L-mode
Apr 9 2004 04:25:48:637PM1040409027John RiceLSN, RF 1.02, L-mode
Apr 9 2004 04:38:10:560PM1040409028John RiceLSN, RF 1.23, H-mode
Apr 9 2004 04:49:05:250PM1040409029John RiceSSEP +.25, RF 2.13, L-mode
Apr 9 2004 05:04:17:523PM1040409030John RiceSSEP +.10, RF 2.17, L-mode

Physics Operator Comments
Apr 9 2004 08:37:42:340AMDmitri MossessianMP#375 H-mode threshold and SSEP

Session leader: Rice
Physics operator: Mossessian

Overnight ECDC in D2 at 2e-4 Torr

Run begins at 09:00 and ends at 17:00.

Power systems the same as 1040220001

A-coils should be enabled in the standard configuration.

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 was is Hybrid disabled (PG2)
fill C-side with 40 psi D2 Hybrid enabled (PG3)


Enable the following gatevalves: ECE, VUV, DNB

Run plan:

Start with 1040220001. Run segment 4 - SSEP control.
Scan SSEP from LN to UP through DN and establish H-mode threshold dependance on SSEP.
Apr 9 2004 08:41:46:977AMDmitri MossessianLoaded segment 4 from 1040220001 into segment 4.
Ip=0.8 MA, nl=8e19. TF current - 150 kA

Will run from segment 4.

Left segment 1 from yesterday since we needed lower than normal Br_0 and prepuffs yesterday for good
startup.

Load Clean OK.
Apr 9 2004 09:12:02:450AM1040409001Dmitri MossessianFizzle. Both Br and Bz look too negative.

Next shot: Br offset -1 mT -> 0 mT, Bz up by moving IC_EF4U -1345 -> -1330.
Apr 9 2004 09:26:58:517AM1040409002Dmitri MossessianPlasma. Good startup. SSEP=-0.4

Next shot: nl up 8e19 -> 8.5e19
Apr 9 2004 09:36:26:197AM1040409003Dmitri MossessianPlasma.

Next shot: no changes
Apr 9 2004 09:53:18:970AM1040409004Dmitri MossessianPlasma.

Next shot: SSEP 3 mm up to -0.1 cm
Apr 9 2004 10:06:42:180AM1040409005Dmitri MossessianPlasma. Nice DN with SSEP around 0

Next shot: no change
Apr 9 2004 10:46:47:897AM1040409006Dmitri MossessianPlasma.

Next shot: no change
Apr 9 2004 10:48:03:260AM1040409007Dmitri MossessianPlasma.

Next shot: RCUR up 2 mm at 0.8 sec to make right gap steadier. SSEP up 3 mm.
Apr 9 2004 11:01:08:403AM1040409008Dmitri MossessianPlasma. Upper null - SSEP around 0.3. Right gap = 2.2 cm const.

Next shot: RCUR up 3 mm to decrease right gap to ~ 1.5 cm
Apr 9 2004 11:12:09:437AM1040409009Dmitri MossessianPlasma. Disrupted at 0.93 sec due to injection

Next shot: no change
Apr 9 2004 11:21:56:670AM1040409010Dmitri MossessianPlasma. Steady righ gap around 1.7 cm

Next shot: no change
Apr 9 2004 11:54:27:783AM1040409012Dmitri MossessianPlasma.

Next shot: TF 149000 -> 148440 to drop Bt 0.02 T at Amanda's request
Apr 9 2004 12:21:46:903PM1040409013Dmitri MossessianPlasma.

Next shot: To increase SSEP more and keep control over CLEARIN load CLEARIN wire
from shot 1040220001 segment 3 (UN) where its controller is referenced to upper
x-point.
Load wire 4, seg 3, 1040220001 into wire 4, seg 4
Load wire 1, seg 3, 1040220001 into wire 1, seg 4 (RCUR)
SSEP up 3 mm
Apr 9 2004 12:27:10:847PM1040409014Dmitri MossessianPlasma. Right and left gaps around 1 cm, SSEP around 6 mm.

Next shot: no change
Apr 9 2004 12:47:37:147PM1040409015Dmitri MossessianPlasma. Disrupted aaaat 1.62 due to injection

Next shot: SSEP up to 2 cm
Apr 9 2004 01:00:00:023PM1040409016Dmitri MossessianPlasma. Ran fine, but the shape is out of control sice the demand for SSEP exceeds allowable bounds.

Next shot: Reload segment4 from shot 15. Load segment 3 from 1040220001, adjusted nl and TF. Run segment 3 for UN
Apr 9 2004 01:22:30:450PM1040409018Dmitri MossessianPlasma. Disrupted at 1.6 sec due to injection.

Next shot: nl up to 9e19
Apr 9 2004 01:44:59:327PM1040409019Dmitri MossessianPlasma. Disrupted at 1.3 sec due to injection.

Next shot: nl up to 9.5e19. RXU 5 mm more positive to move upper strike point and
avoid disruptions
Apr 9 2004 01:52:59:980PM1040409020Dmitri MossessianPlasma. Disrupted at .3 sec due to injection.

Next shot: adjusted RXU again to move out later.
Apr 9 2004 02:01:12:260PM1040409020Dmitri MossessianSlight delay - EF4 fuse needs to be replaced.
Apr 9 2004 03:13:29:040PM1040409022Dmitri MossessianPlasma. Disrupted early - problems with TCI led to lost feedback and uncontrolled rise of ne.

Next shot: no PCS changes.
Apr 9 2004 03:32:18:350PM1040409023Dmitri MossessianPlasma.

Next shot: Go to segment 4 again. SSEP -> -1 cm for LN
Apr 9 2004 03:57:20:623PM1040409024Dmitri MossessianDud. Hybrid problems.

Next shot: no power test
Apr 9 2004 04:23:13:007PM1040409027Dmitri MossessianPlasma. Disrupted at 1.4 sec due to injection

Next shot: no PCS change
Apr 9 2004 04:38:07:670PM1040409028Dmitri MossessianPlasma.

Next shot: SSEP to +1.5 mm
Apr 9 2004 04:57:26:763PM1040409029Dmitri MossessianPlasma. TCI feedback is not working, we got nl~5e19

Next shot: turn off nl feedback (set gains on nl to 0 in seg. 4). Paste gas trace from shot 27 into
PG3 program. SSEP down 1 mm
Apr 9 2004 05:13:03:897PM1040409030Dmitri MossessianPlasma. Good density trace

Engineering Operator Comments
ShotTimeTypeStatusComment
109:03:49:667AMPlasmaOk
209:16:18:163AMPlasmaOk
309:31:28:060AMPlasmaOk
409:46:40:350AMPlasmaOk
510:01:42:077AMPlasmaOk
610:21:32:403AMPlasmaOk
710:36:38:553AMPlasmaOk
810:49:50:963AMPlasmaOk
911:04:06:957AMPlasmaOk
1011:17:02:350AMPlasmaOk
1111:31:51:373AMPlasmaOk
1211:46:20:927AMPlasmaOk
1312:03:39:110PMPlasmaOk
1412:22:32:827PMPlasmaOk
1512:36:03:110PMPlasmaOk
1612:51:55:010PMPlasmaOk
1701:05:00:780PMPlasmaOk
1801:17:48:440PMPlasmaOk
1901:30:50:557PMPlasmaOk
2001:45:43:530PMPlasmaBadEF4 Type 1 Fault
2102:45:34:670PMTestOkEF4 double swing test
2203:06:55:390PMPlasmaOk
2303:21:09:583PMPlasmaOk
2403:35:14:387PMPlasmaOk
2503:57:37:407PMTestOk
2604:06:01:200PMPlasmaOk
2704:18:50:110PMPlasmaOk
2804:31:46:147PMPlasmaOk
2904:45:05:337PMPlasmaOk
3005:00:22:003PMPlasmaOk