Alcator C-Mod Run 980218 Information

Miniproposals

Miniproposal: 189

Date Filed: 10/3/1997

Title: D(H) Minority and Mode Conversion Heating

First Author: Steve Wukitch

Session Leader: Steve Wukitch (shots 1-35)

Operators
Session leader(s):	Steve Wukitch
Physics operator(s):	Ian Hutchinson
Engineering operator(s):	Unknown

Engineering Operator Run Comment
mp150a

Session Leader Plans

Physics Operators Plans

Session Leader Summaries

Entered: Jul 7 2004 03:49:18:257PM

Author: To Be Determined

****980218****980218****980218****980218****980218****980218****980218

MP189 D(H) Minority and Mode Conversion Heating

------------------------------------------------------------------------------
Engineering setup for 980218:

Engineering setup as on 980217007, with TF under HYBRID control

Gas setup - fill K-side with 30 PSI of D2, hybrid enable
fill B-top with 6 PSI of D2, hybrid enable
fill B-side-lower with 1 PSI of Ar, hybrid disable

ECDC in He overnight before the run.
ECDC in D2 2 hours before the run. (same prescription as over the weekend)
Second day after Friday night boronization.
RF position feedback is off

Gate Valves:
ECE
PCX (check with Rejean before opening)

The goals for today are to:

1. Start with 5.4T fiducial discharges and step up with constant q
5.4T, 0.8 MA, nl_04~1.0, q95~4.5 -- evaluate machine
conditions
2. Scan H concentration at 5.4 T, Ip->1.0 MA, 1.25 MW power
modulation. -- tentative (recall 980217022)

fill K-side with
H/H+D~5% 2 psi of H2 plus 38 PSI of D2, hybrid enable
2 x (5.4 T & 5.1 T, holding q95~constant)
H/H+D~10% 4 psi of H2 plus 36 PSI of D2, hybrid enable
2 x (5.4 T & 5.1 T, holding q95~constant)
H/H+D~20% 8 psi of H2 plus 32 PSI of D2, hybrid enable
2 x (5.4 T & 5.6 T, holding q95~constant)
H/H+D~30% 12 psi of H2 plus 28 PSI of D2, hybrid enable
2 x (5.4 T & 5.7 T, holding q95~constant)
H/H+D~40% 16 psi of H2 plus 24 PSI of D2, hybrid enable
2 x (5.4 T & 5.8 T, holding q95~constant)
********************************************************************
****Do not worry about final pressure after opening output valve****
********************************************************************
(18-25 shots)
3. adjust Bt to maximize central heating from mode conversion
(3 discharges)
4. reduce H concentration by filling K-side with 30 PSI of D2, hybrid enable
(4-5 discharges)

Summary:

Physics goals were partially accomplished eventhough the plasma and
the RF performance degraded with increasing H concentration. By the
end of the day, Mo radiation was up by a factor of 10 compared to
earlier (028 compared with 006). It was hoped that low H
concentration would be obtain after the H concentration scan (by
discharges without H), but the concentration was ~10% (PCX) on 035.
Discharge performance was recovering as H decreased.

Things learned:

1. Raising H improved central heating (980218008 and 011 were best).
Total absorbed power will require further analysis.

2. D(H) mode conversion was observed for H/H+D~20-30% (980218025-028).
Required large modulated signal to locate.
3. For low H concentration (980218008 & 980218011), the sawteeth
locked to the RF modulation frequency. Perhaps indicating strong
central heating.

4. Inner wall B-dot signal decreased with increasing H concentration.
May be related to increasing decreasing transmission through core
cutoff layer. The difficulty in running the RF at high H
concentration also suggests less transmission and higher reflection at
the cutoff position.

5. H concentration was difficult to control. Having PCX available to
measure what the concentration was important. Developing a method
that would allow some control over H/H+D, however, is important for
optimizing the RF absorption.

An interesting RF issue which was not studied in this run is the mode
conversion density dependence. This was not explored due to time
restraints. The corre evanescant region thickness scales as the
square root of the majority density. Lowering the density should
increase the mode converted fraction of absorbed power.

reload from 980217007 ST1 PS1 ST2 PS2
0.8 kA, nl_04~1 fiducial

001 plasma early disrupt ~0.32 sec 600 406 2544 933
002 plasma EDA 112 kJ
H/(H+D)~2%
next shot: Ip->1.0 MA
003 plasma EDA 189 kJ
#1 tripping on voltage limit during modulation
H/(H+D)~2%
004 plasma EDA 180 kJ
#1 tripping on voltage limit during modulation
H/(H+D)~2.5%
005 plasma EDA 172 kJ
#1 tripping on voltage limit during modulation
H/(H+D)~2.5%
006 plasma EDA 172 kJ
finally good modulation
H/(H+D)~2.5%

next shot: H/H+D mixture to 5% 602 411 2562 943
007 fizzle
008 plasma EDA 186 kJ
#1: single voltage limit during modulation
#2: single voltage limit during startup
sawteeth locked to RF modulation after 2-3 cycles
H/(H+D) ratio starts at about 15% and slowly comes down to 5%
at the end of the shot.
Ti from neutrons with 10% Hydrogen fraction

009 plasma early disruption -- brick
010 fizzle
011 plasma EDA 185 kJ
good RF modulation
sawteeth locked to RF modulation after 2-3 cycles
H/(H+D) ratio starts at about 15% and stays approximately
at that level.
Ti from neutrons with 15% Hydrogen fraction

next shot: H/H+D mixture to 10% 2550 959
012 Tuesday test (ohmic)
013 Tuesday test

long break

014 dud
015 plasma EDA
H/(H+D) ratio starts at about 13% and settles down to
8% towards the end.
poor RF modulation
Ti from neutrons with 11% Hydrogen fraction
016 plasma EDA
few voltage faults
H/(H+D) ratio starts at about 11% and settles down to
8% towards the end.
better RF modulation
Ti from neutrons with H/H+D~ 9.5%
next shot: 5.1 T
017 plasma EDA
lots of trips late in modulation
BT~5.4T
H/(H+D) ratio starts at about 10% and settles down to
7% towards the end.
Ti from neutrons with H/H+D~ 8.5%

next shot: try 5.1 T again Prf timing: start .55 sec (50 msec delay)
018 fizzle
019 fizzle
020 plasma EDA and goes Elm-free
ECE is cutoff
sawteeth and RF modulation are NOT locked
H/(H+D) ratio starts at about 10% and settles down to
8% towards the end.
Ti from neutrons with H/H+D~ 9%
next shot: back to 5.4 T and 30% H/H+D mixture

021 plasma EDA
lousy RF
H/(H+D) ratio starts at about 18% and settles down to
10% towards the end.
Ti from neutrons with H/H+D~ 14%
022 plasma EDA
H/(H+D) ratio starts at about 19% and settles down to
12% towards the end.
Ti from neutrons with H/H+D~ 15.5%

next shot: lowered the RF power
023 plasma EDA
modulation is better
H/(H+D) ratio starts at about 20% and settles down to
13% towards the end.
Ti from neutrons with H/H+D~ 16.5%

next shot: BT->5.1
024 plasma multiple EDA/EF
H/(H+D) ratio starts at about 22% and settles down to
15% towards the end.
Ti from neutrons with H/H+D~ 18.5%

next shot: BT->5.4T
025 plasma multiple EDA/EF
signs of MC on central GPC_1 channels
H/(H+D) ratio starts at about 22% and settles down to
17% towards the end.
Ti from neutrons with H/H+D~ 19.5%

026 plasma multiple EDA/EF
signs of MC on central GPC_1 channels
H/(H+D) ratio starts at about 23% and settles down to
18% towards the end.
Ti from neutrons with H/H+D~20.5%

next shot: increase H/H+D~50% in plenum
027 plasma multiple EDA/EF
various faults on RF -- some useable
signs of MC further off-axis
H/(H+D) ratio starts at about 30% and settles down to
25% towards the end.
Ti from neutrons with H/H+D~27.5%

028 plasma multiple EDA/EF
various faults on RF -- modulation is in L-mode
signs of MC further off-axis
H/(H+D) ratio starts at about 32% and settles down to
24% towards the end.
Ti from neutrons with H/H+D~28%
next shot: plenum is D only; NO H mixed in plenum
029 plasma multiple H-modes/L-mode
only one RF trip on #2
H/(H+D) ratio starts at about 17% and settles down to
21% towards the end.
Ti from neutrons with H/H+D~19%
next shot: 2502 984
030 plasma multiple H-modes/L-mode
H/(H+D) ratio starts at about 14% and settles down to
17% towards the end.
Ti from neutrons with H/H+D~15.5%

next shot: 606 408
031 plasma multiple H-modes
#1 screen overcurrent
H/(H+D) ratio starts at about 12% and settles down to
16% towards the end. (up)
Ti from neutrons with H/H+D~14%

032 plasma multiple H-modes
H/(H+D) ratio starts at about 11% and settles down to
12% towards the end. (up)
Ti from neutrons with H/H+D~11.5%

next shot: no modulation and raise power by ~200 kW and 20% increase
of nl_04. 608 408 2527 962
033 plasma early disruption
034 fizzle
035 plasma EDA
H/(H+D) ratio starts at about 9% and settles down to
11% towards the end. (up)

Physics Operator Summaries

Entered: Jul 7 2004 04:36:59:550PM

Author: To Be Determined

Physop Report 9890218
MP 189
Minority-Mode Conversion D-H heating.
____________________________________

SL Wukitch
PO Hutch

This run scanned the H-minority concentration upward till shot 28 and
then, using pure D2 puff, downward till the end of the run.

A weak optimum for heating was observed at a few percent minority,
slightly above the natural H-level for recent runs. At higher hydrogen
levels much less satisfactory heating is obtained even though H-mode
is achieved. Also, impurity accumulation and more "ELM-free" like
behaviour is obtained at higher H-fraction, perhaps because the
heating power is really less.

The H-fraction seemed to reduce only slowly, by about 2% per shot,
once the H-puffing was stopped. There were clear signs that the plasma
was returning to more favorable operation, but not enough time to get
all the way there. (In the neutrals logbook Boivin has made notes
about the H-fraction measurements.) The last shot, 35, has reasonable
EDA behaviour, at about 10% H fraction reported.

It was observed that there is a clear correlation between divertor pressure
drop and EDA-like behaviour. The pump-out stops when the D-alpha rolls over
and impurity accumulation begins. Since this divertor pressure variation
can be a factor of 2 or so, and the impurity accumulation is usually
accompanied by a plasma density rise, this behaviour is the opposite of
what might be expected if there is some fixed inventory shared between
the divertor neutrals and the plasma.

Scorecard
_________
Shot,Duration(s),Ipmax(MA) Shot,Duration(s),Ipmax
1 0.323 0.766 2 1.666 0.818
3 1.667 1.024 4 1.668 1.027
5 1.669 1.024 6 1.668 1.027
7 0.000 0.047 8 1.669 1.024
9 0.503 0.998 10 0.000 0.034
11 1.669 1.024 12 0.000 0.021
13 0.000 0.021 14 0.000 0.024
15 1.668 1.027 16 1.671 1.024
17 1.670 1.024 18 0.000 0.036
19 0.000 0.036 20 1.663 1.018
21 1.671 1.019 22 1.661 1.019
23 1.663 1.014 24 1.602 1.008
25 1.663 1.017 26 1.641 1.014
27 1.679 1.009 28 1.616 1.009
29 1.614 1.017 30 1.663 1.019
31 1.658 1.019 32 1.666 1.019
33 0.389 0.838 34 0.000 0.037
35 1.664 1.019
Finished summary for 980218 Total of 35 shots.
35 shots. 27 plasmas. 5 fizzles. 3 duds.

Details
_______

--------------------------------------------------------------------------------
980218xxx HUTCH PHYSICS_OPERATOR 18-FEB-1998 08:33:28.97
. . . . . . . . . . . . . . . . . . . .
MP 189
Minority-Mode Conversion D-H heating.

Overnight ECDC in Helium till 2.05. Then 2 hours of D2 ECDC.

Load from 980217007.
EF4 to -1340A.
--------------------------------------------------------------------------------
980218001 HUTCH PHYSICS_OPERATOR 18-FEB-1998 08:51:01.23
. . . . . . . . . . . . . . . . . . . .
Plasma. Disrupts at .3s. A vertical position problem.

Get magnetics error messages.

Reply received on PHYSOP from user MDSSERVER at BAROLO Batch 08:37:28
\mag_bp_coils.signals:bp26_bc has a baseline offset -2.7E-02
Reply received on PHYSOP from user MDSSERVER at BAROLO Batch 08:37:28
\mag_bp_coils.signals:bp23_bc has a baseline offset -7.4E-01

Seems that bp23_bc is being used and has a problem.
This seems to have occurred on shot 35 yesterday. The coil appears to have
come back from the dead at the disruption today.
--------------------------------------------------------------------------------
980218002 HUTCH PHYSICS_OPERATOR 18-FEB-1998 09:11:47.11
. . . . . . . . . . . . . . . . . . . .
Repeat. Plasma. Coil seems to have fixed itself. Some runaways, like previous.

Load shot 22. It is running in segment 3.
EF4 to -1335.
Gas fill puff to 16ms, from 14.
Enable Argon. (20ms).
--------------------------------------------------------------------------------
980218003 HUTCH PHYSICS_OPERATOR 18-FEB-1998 09:22:59.83
. . . . . . . . . . . . . . . . . . . .
Plasma. Longish H-mode. Injection at .85s causes plasma to become more ELM-free.
RF trips later.
--------------------------------------------------------------------------------
980218004 HUTCH PHYSICS_OPERATOR 18-FEB-1998 09:33:39.21
. . . . . . . . . . . . . . . . . . . .
Plasma. Still significant radiation.

zcur to -1.2cm from -1.5
--------------------------------------------------------------------------------
980218005 HUTCH PHYSICS_OPERATOR 18-FEB-1998 09:52:23.21
. . . . . . . . . . . . . . . . . . . .
Plasma.

zcur to -1 cm.
--------------------------------------------------------------------------------
980218006 HUTCH PHYSICS_OPERATOR 18-FEB-1998 10:20:02.76
. . . . . . . . . . . . . . . . . . . .
Plasma. RF folks are satisfied.

Argon puff to 16ms from 12ms. I think I looked in the wrong segment before.
2psi H +38psi D into K-side (pg 3, main gas puff).
Invrease pg3 V to 50V prior to .2s.
--------------------------------------------------------------------------------
980218007 HUTCH PHYSICS_OPERATOR 18-FEB-1998 10:37:42.85
. . . . . . . . . . . . . . . . . . . .
25minute break for gas change to 5% H.
Plasma 55kA and dies at 18ms. Br has drifted up about mT.

Br offset to 4.5mT from 5mT.
--------------------------------------------------------------------------------
980218008 HUTCH PHYSICS_OPERATOR 18-FEB-1998 10:42:11.48
. . . . . . . . . . . . . . . . . . . .
Plasma.

No changes.
--------------------------------------------------------------------------------
980218009 HUTCH PHYSICS_OPERATOR 18-FEB-1998 10:52:51.18
. . . . . . . . . . . . . . . . . . . .
Plasma Disrupts at .497s. Brick at .48s.
--------------------------------------------------------------------------------
980218010 HUTCH PHYSICS_OPERATOR 18-FEB-1998 11:04:19.78
. . . . . . . . . . . . . . . . . . . .
Fizzle. 40kA dies at 13ms. A very early breakdown.
Br a tad negative. Bz also low.

Ef4 to -1330 from -1335A
--------------------------------------------------------------------------------
980218011 HUTCH PHYSICS_OPERATOR 18-FEB-1998 11:26:16.88
. . . . . . . . . . . . . . . . . . . .
Plasma.

OH2U coax resitance warning. 1.01 uohm.
Replace K-side with 4psi H plus 36 psi D.
Do Tuesday test.
--------------------------------------------------------------------------------
980218012 HUTCH PHYSICS_OPERATOR 18-FEB-1998 11:35:09.60
. . . . . . . . . . . . . . . . . . . .
Tuesday test. OH2 resistance remains at .8 uohm. Rather high.

Cooling in a different mode for about 12min.
Another.
--------------------------------------------------------------------------------
980218013 HUTCH PHYSICS_OPERATOR 18-FEB-1998 11:46:01.30
. . . . . . . . . . . . . . . . . . . .
No significant change in resistance.

Go for full plasma on next shot.
--------------------------------------------------------------------------------
980218014 HUTCH PHYSICS_OPERATOR 18-FEB-1998 12:01:41.63
. . . . . . . . . . . . . . . . . . . .
Dud.

Granetz substituting as physop for Ian until 13:00

MFLUX INIT scope looks identical to last plasma shot (011). Gas pressure okay.

Next shot: just try again, no changes
--------------------------------------------------------------------------------
980218015 HUTCH PHYSICS_OPERATOR 18-FEB-1998 12:11:40.62
. . . . . . . . . . . . . . . . . . . .
Plasma. OH2U coax resistance is 0.9 uohm. RF had troubles after 0.9 s.

Next shot: repeat, no PCS changes.
--------------------------------------------------------------------------------
980218016 HUTCH PHYSICS_OPERATOR 18-FEB-1998 12:31:06.17
. . . . . . . . . . . . . . . . . . . .
Plasma. RF did better.

Next shot: reduce toroidal field to 5.1 T (141kA).
--------------------------------------------------------------------------------
980218017 HUTCH PHYSICS_OPERATOR 18-FEB-1998 12:46:01.30
. . . . . . . . . . . . . . . . . . . .
Plasma. Btor did not change. Operator error: segment 3 is being used instead of segment 2.

Next shot: reduce Btor to 5.1 T in segment 3 also. Increase argon puff to 20 ms in segment 3.
--------------------------------------------------------------------------------
980218018 HUTCH PHYSICS_OPERATOR 18-FEB-1998 13:02:24.18
. . . . . . . . . . . . . . . . . . . .
Fizzle. Br looks a tiny bit high. Btor = 5.15 T.

Next shot: reduce Br offset from 0.0045 to 0.0040 T. Reduce I_TF by another 1 kA.
--------------------------------------------------------------------------------
980218019 HUTCH PHYSICS_OPERATOR 18-FEB-1998 13:10:32.31
. . . . . . . . . . . . . . . . . . . .
Fizzle. Two in a row.

Next shot: Change IC_EF4 from -1330 to -1340 amps.
--------------------------------------------------------------------------------
980218020 HUTCH PHYSICS_OPERATOR 18-FEB-1998 13:41:42.55
. . . . . . . . . . . . . . . . . . . .
Plasma.

Ian returns as physop.
Gas mix to 12psi H plus 28psi D.
Import segment 3 from shot 16 to return to 5.4T.
Load.
--------------------------------------------------------------------------------
980218021 HUTCH PHYSICS_OPERATOR 18-FEB-1998 13:55:25.06
. . . . . . . . . . . . . . . . . . . .
Plasma.

zxl to -1.2cm from -1.5cm.
--------------------------------------------------------------------------------
980218022 HUTCH PHYSICS_OPERATOR 18-FEB-1998 14:14:03.87
. . . . . . . . . . . . . . . . . . . .
Plasma.

zxl to -1cm.
Argon to 19ms.
--------------------------------------------------------------------------------
980218023 HUTCH PHYSICS_OPERATOR 18-FEB-1998 14:35:26.45
. . . . . . . . . . . . . . . . . . . .
Plasma.

Bt to 142kA.
--------------------------------------------------------------------------------
980218024 HUTCH PHYSICS_OPERATOR 18-FEB-1998 14:52:36.68 . . . .
. . . . . . . . . . . . . . . .

Plasma. I notice that this has almost no divertor pump out during the
H-mode phase. It has a lot of impurity accumulation and is much less
EDAish in character. Looking back at shots today, there is, it seems
quite a good correlation between divertor pumpout and EDA character.

Bt to 150kA.
--------------------------------------------------------------------------------
980218025 HUTCH PHYSICS_OPERATOR 18-FEB-1998 15:00:04.12
. . . . . . . . . . . . . . . . . . . .
Plasma. No pumpout.
--------------------------------------------------------------------------------
980218026 HUTCH PHYSICS_OPERATOR 18-FEB-1998 15:31:26.91
. . . . . . . . . . . . . . . . . . . .
Plasma. Similar.

Purge k-side and fill with 20 psi H plus 20 psi D.
--------------------------------------------------------------------------------
980218027 HUTCH PHYSICS_OPERATOR 18-FEB-1998 15:31:47.63
. . . . . . . . . . . . . . . . . . . .
Plasma
--------------------------------------------------------------------------------
980218028 HUTCH PHYSICS_OPERATOR 18-FEB-1998 15:49:09.97
. . . . . . . . . . . . . . . . . . . .
Plasma. Some runaways.

Refill k-side with 40 psi D.
--------------------------------------------------------------------------------
980218029 HUTCH PHYSICS_OPERATOR 18-FEB-1998 16:01:21.21
. . . . . . . . . . . . . . . . . . . .
Plasma. Still not good EDA. Perhaps we need some shots to get rid of H.

--------------------------------------------------------------------------------
980218030 HUTCH PHYSICS_OPERATOR 18-FEB-1998 16:12:17.15
. . . . . . . . . . . . . . . . . . . .
Plasma. Longer RF pulse before Lmode. Slower impurity accumulation.
Signs of divertor pump-out.
--------------------------------------------------------------------------------
980218031 HUTCH PHYSICS_OPERATOR 18-FEB-1998 16:25:40.90
. . . . . . . . . . . . . . . . . . . .
Plasma. Not much improvement.
--------------------------------------------------------------------------------
980218032 HUTCH PHYSICS_OPERATOR 18-FEB-1998 16:38:55.86
. . . . . . . . . . . . . . . . . . . .
Plasma. Similar.

Raise nl04 to 1.1 from .9.
--------------------------------------------------------------------------------
980218033 HUTCH PHYSICS_OPERATOR 18-FEB-1998 16:48:18.85
. . . . . . . . . . . . . . . . . . . .
Plasma. Disrupts at .38s. A brick.
--------------------------------------------------------------------------------
980218034 HUTCH PHYSICS_OPERATOR 18-FEB-1998 16:58:47.19
. . . . . . . . . . . . . . . . . . . .
Fizzle.

Br offset to 4.5mT.
------------------------------------------------------------------------------ 980218035 HUTCH PHYSICS_OPERATOR 18-FEB-1998 17:04:46.33 . . . .

Plasma. EDA for .4s. Much better heating. But no divertor pump-out
worth talking about. This may be a result of the higher nl04
setting. Substantial Mo.

Session Leader Comments

Feb 18 1998 08:19:57:360AM Steve Wukitch MP189 D(H) Minority and Mode Conversion Heating

------------------------------------------------------------------------------
Engineering setup for 980218:

Engineering setup as on 980217007, with TF under HYBRID control

Gas setup - fill K-side with 30 PSI of D2, hybrid enable
fill B-top with 6 PSI of D2, hybrid enable
fill B-side-lower with 1 PSI of Ar, hybrid disable

ECDC in He overnight before the run.
ECDC in D2 2 hours before the run. (same prescription as over the weekend)
Second day after Friday night boronization.
RF position feedback is off

Gate Valves:
ECE
PCX (check with Rejean before opening)

The goals for today are to:

1. Start with 5.4T fiducial discharges and step up with constant q
5.4T, 0.8 MA, nl_04~1.0, q95~4.5 -- evaluate machine
conditions
2. Scan H concentration at 5.4 T, Ip->1.0 MA, 1.25 MW power
modulation. -- tentative

fill K-side with
H/H+D~5% 2 psi of H2 plus 38 PSI of D2, hybrid enable
2 x (5.4 T & 5.1 T, holding q95~constant)
H/H+D~10% 4 psi of H2 plus 36 PSI of D2, hybrid enable
2 x (5.4 T & 5.1 T, holding q95~constant)
H/H+D~20% 8 psi of H2 plus 32 PSI of D2, hybrid enable
2 x (5.4 T & 5.6 T, holding q95~constant)
H/H+D~30% 12 psi of H2 plus 28 PSI of D2, hybrid enable
2 x (5.4 T & 5.7 T, holding q95~constant)
H/H+D~40% 16 psi of H2 plus 24 PSI of D2, hybrid enable
2

Feb 18 1998 08:42:48:400AM 980218001 Steve Wukitch 001 plasma early disrupt ~0.32 sec

Feb 18 1998 10:26:08:900AM 980218002 Steve Wukitch 002 plasma EDA 112 kJ
H/(H+D)~2%
next shot: Ip->1.0 MA

Feb 18 1998 10:26:25:140AM 980218003 Steve Wukitch 003 plasma EDA 189 kJ
#1 tripping on voltage limit during modulation
H/(H+D)~2%

Feb 18 1998 10:26:45:620AM 980218004 Steve Wukitch 004 plasma EDA 180 kJ
#1 tripping on voltage limit during modulation
H/(H+D)~2.5%

Feb 18 1998 10:47:18:820AM 980218005 Steve Wukitch 005 plasma EDA 172 kJ
#1 tripping on voltage limit during modulation
H/(H+D)~2.5%

Feb 18 1998 10:47:42:240AM 980218006 Steve Wukitch 006 plasma EDA 172 kJ
finally good modulation
H/(H+D)~2.5%

next shot: H/H+D mixture to 5%

Feb 18 1998 10:28:59:550AM 980218007 Steve Wukitch 007 55 kA fizzle

Feb 18 1998 10:57:15:730AM 980218008 Steve Wukitch 008 plasma EDA 186 kJ
#1: single voltage limit during modulation
#2: single voltage limit during startup
sawteeth locked to RF modulation after 2-3 cycles
H/(H+D) ratio starts at about 15% and slowly comes down to 5%
at the end of the shot.

Feb 18 1998 10:49:44:190AM 980218009 Steve Wukitch 009 plasma early disruption -- brick

Feb 18 1998 10:56:58:490AM 980218010 Steve Wukitch 010 fizzle

Feb 18 1998 11:53:33:280AM 980218011 Steve Wukitch 011 plasma EDA 185 kJ
good RF modulation
sawteeth locked to RF modulation after 2 cycles

Feb 18 1998 11:52:57:750AM 980218014 Steve Wukitch 014 dud

Feb 18 1998 12:16:36:560PM 980218015 Steve Wukitch 015 plasma EDA
H/(H+D) ratio starts at about 13% and settles down to
8% towards the end.
poor RF modulation

Feb 18 1998 12:51:03:040PM 980218016 Steve Wukitch 016 plasma EDA
few voltage faults
H/(H+D) ratio starts at about 11% and settles down to
8% towards the end.
better RF modulation

next shot: 5.1 T

Feb 18 1998 12:51:30:520PM 980218017 Steve Wukitch 017 plasma EDA
lots of trips late in modulation
BT~5.4T

next shot: try 5.1 T again Prf timing: start .55 sec (50 msec delay)

Feb 18 1998 01:06:11:000PM 980218018 Steve Wukitch 018 fizzle

Feb 18 1998 01:06:23:690PM 980218019 Steve Wukitch 019 fizzle

Feb 18 1998 01:28:02:750PM 980218020 Steve Wukitch 020 plasma EDA and goes Elm-free
ECE is cutoff
sawteeth and RF modulation are NOT locked

next shot: back to 5.4 T and 30% H/H+D mixture

Feb 18 1998 02:21:39:030PM 980218021 Steve Wukitch 021 plasma EDA
lousy RF
H/(H+D) ratio starts at about 18% and settles down to
10% towards the end.
Ti from neutrons with H/H+D~ 14%

Feb 18 1998 02:21:56:370PM 980218022 Steve Wukitch 022 plasma EDA
H/(H+D) ratio starts at about 19% and settles down to
12% towards the end.
Ti from neutrons with H/H+D~ 15.5%

next shot: lowered the RF power

Feb 18 1998 02:22:26:730PM 980218023 Steve Wukitch 023 plasma EDA
modulation is better

next shot: BT->5.1

Feb 18 1998 03:00:43:640PM 980218024 Steve Wukitch 024 plasma multiple EDA/EF
H/(H+D) ratio starts at about 22% and settles down to
15% towards the end.
Ti from neutrons with H/H+D~ 18.5%

next shot: BT->5.4T

Feb 18 1998 03:02:37:660PM 980218025 Steve Wukitch 025 plasma multiple EDA/EF
signs of MC on central GPC_1 channels

next shot: repeat

Feb 18 1998 03:05:00:540PM 980218026 Steve Wukitch 026 plasma multiple EDA/EF
signs of MC on central GPC_1 channels

next shot: increase H/H+D~50% in plenum

Feb 18 1998 03:44:00:120PM 980218027 Steve Wukitch 027 plasma multiple EDA/EF
various faults on RF -- some useable
signs of MC further off-axis
H/(H+D) ratio starts at about 30% and settles down to
25% towards the end.
Ti from neutrons with H/H+D~27.5%

Feb 18 1998 03:46:34:510PM 980218028 Steve Wukitch 028 plasma multiple EDA/EF
various faults on RF -- modulation is in L-mode
signs of MC further off-axis
H/(H+D) ratio starts at about 32% and settles down to
24% towards the end.

next shot: plenum is D only; NO H mixed in plenum

Feb 18 1998 04:13:09:980PM 980218029 Steve Wukitch 029 plasma multiple H-modes/L-mode
only one RF trip on #2
H/(H+D) ratio starts at about 17% and settles down to
21% towards the end.

Feb 18 1998 04:15:08:500PM 980218030 Steve Wukitch 030 plasma multiple H-modes/L-mode
H/(H+D) ratio starts at about 14% and settles down to
17% towards the end.

Feb 18 1998 04:21:38:410PM 980218031 Steve Wukitch 031 plasma multiple H-modes
#1 screen overcurrent
H/(H+D) ratio starts at about 12% and settles down to
16% towards the end. (up)

Feb 18 1998 04:49:24:790PM 980218032 Steve Wukitch 032 plasma multiple H-modes
H/(H+D) ratio starts at about 11% and settles down to
12% towards the end. (up)
Ti from neutrons with H/H+D~11.5%

next shot: no modulation and raise power by ~200 kW and 20% increase
of nl_04. 608 408 2527 962

Feb 18 1998 04:49:57:790PM 980218033 Steve Wukitch 033 plasma early disruption

Feb 18 1998 04:50:19:030PM 980218034 Steve Wukitch 034 fizzle

Feb 18 1998 05:08:55:790PM 980218035 Steve Wukitch 035 plasma EDA
H/(H+D) ratio starts at about 9% and settles down to
11% towards the end. (up)

Physics Operator Comments

Feb 18 1998 08:33:28:970AM Ian Hutchinson MP 189
Minority-Mode Conversion D-H heating.

Overnight ECDC in Helium till 2.05. Then 2 hours of D2 ECDC.

Load from 980217007.
EF4 to -1340A.

Feb 18 1998 08:51:01:230AM 980218001 Ian Hutchinson Plasma. Disrupts at .3s. A vertical position problem.

Get magnetics error messages.

Reply received on PHYSOP from user MDSSERVER at BAROLO Batch 08:37:28
\mag_bp_coils.signals:bp26_bc has a baseline offset -2.7E-02
Reply received on PHYSOP from user MDSSERVER at BAROLO Batch 08:37:28
\mag_bp_coils.signals:bp23_bc has a baseline offset -7.4E-01

Seems that bp23_bc is being used and has a problem.
This seems to have occurred on shot 35 yesterday. The coil appears to have
come back from the dead at the disruption today.

Feb 18 1998 09:11:47:110AM 980218002 Ian Hutchinson Repeat. Plasma. Coil seems to have fixed itself. Some runaways, like previous.

Load shot 22. It is running in segment 3.
EF4 to -1335.
Gas fill puff to 16ms, from 14.
Enable Argon. (20ms).

Feb 18 1998 09:22:59:830AM 980218003 Ian Hutchinson Plasma. Longish H-mode. Injection at .85s causes plasma to become more ELM-free.
RF trips later.

Feb 18 1998 09:33:39:210AM 980218004 Ian Hutchinson Plasma. Still significant radiation.

zcur to -1.2cm from -1.5

Feb 18 1998 09:52:23:210AM 980218005 Ian Hutchinson Plasma.

zcur to -1 cm.

Feb 18 1998 10:20:02:760AM 980218006 Ian Hutchinson Plasma. RF folks are satisfied.

Argon puff to 16ms from 12ms. I think I looked in the wrong segment before.
2psi H +38psi D into K-side (pg 3, main gas puff).
Invrease pg3 V to 50V prior to .2s.

Feb 18 1998 10:37:42:850AM 980218007 Ian Hutchinson 25minute break for gas change to 5% H.
Plasma 55kA and dies at 18ms. Br has drifted up about mT.

Br offset to 4.5mT from 5mT.

Feb 18 1998 10:42:11:480AM 980218008 Ian Hutchinson Plasma.

No changes.

Feb 18 1998 10:52:51:180AM 980218009 Ian Hutchinson Plasma Disrupts at .497s. Brick at .48s.

Feb 18 1998 11:04:19:780AM 980218010 Ian Hutchinson Fizzle. 40kA dies at 13ms. A very early breakdown.
Br a tad negative. Bz also low.

Ef4 to -1330 from -1335A

Feb 18 1998 11:26:16:880AM 980218011 Ian Hutchinson Plasma.

OH2U coax resitance warning. 1.01 uohm.
Replace K-side with 4psi H plus 36 psi D.
Do Tuesday test.

Feb 18 1998 11:35:09:600AM 980218012 Ian Hutchinson Tuesday test. OH2 resistance remains at .8 uohm. Rather high.

Cooling in a different mode for about 12min.
Another.

Feb 18 1998 11:46:01:300AM 980218013 Ian Hutchinson No significant change in resistance.

Go for full plasma on next shot.

Feb 18 1998 12:01:41:630PM 980218014 Ian Hutchinson Dud.

Granetz substituting as physop for Ian until 13:00

MFLUX INIT scope looks identical to last plasma shot (011). Gas pressure okay.

Next shot: just try again, no changes

Feb 18 1998 12:11:40:620PM 980218015 Ian Hutchinson Plasma. OH2U coax resistance is 0.9 uohm. RF had troubles after 0.9 s.

Next shot: repeat, no PCS changes.

Feb 18 1998 12:31:06:170PM 980218016 Ian Hutchinson Plasma. RF did better.

Next shot: reduce toroidal field to 5.1 T (141kA).

Feb 18 1998 12:46:01:300PM 980218017 Ian Hutchinson Plasma. Btor did not change. Operator error: segment 3 is being used instead of segment 2.

Next shot: reduce Btor to 5.1 T in segment 3 also. Increase argon puff to 20 ms in segment 3.

Feb 18 1998 01:02:24:180PM 980218018 Ian Hutchinson Fizzle. Br looks a tiny bit high. Btor = 5.15 T.

Next shot: reduce Br offset from 0.0045 to 0.0040 T. Reduce I_TF by another 1 kA.

Feb 18 1998 01:10:32:310PM 980218019 Ian Hutchinson Fizzle. Two in a row.

Next shot: Change IC_EF4 from -1330 to -1340 amps.

Feb 18 1998 01:41:42:550PM 980218020 Ian Hutchinson Plasma.

Ian returns as physop.
Gas mix to 12psi H plus 28psi D.
Import segment 3 from shot 16 to return to 5.4T.
Load.

Feb 18 1998 01:55:25:060PM 980218021 Ian Hutchinson Plasma.

zxl to -1.2cm from -1.5cm.

Feb 18 1998 02:14:03:870PM 980218022 Ian Hutchinson Plasma.

zxl to -1cm.
Argon to 19ms.

Feb 18 1998 02:35:26:450PM 980218023 Ian Hutchinson Plasma.

Bt to 142kA.

Feb 18 1998 02:52:36:680PM 980218024 Ian Hutchinson Plasma. I notice that this has almost no divertor pump out during the H-mode phase. It has
a lot of impurity accumulation and is much less EDAish in character. Looking back at shots
today, there is, it seems quite a good correlation between divertor pumpout and EDA character.

Bt to 150kA.

Feb 18 1998 03:00:04:120PM 980218025 Ian Hutchinson Plasma. No pumpout.

Feb 18 1998 03:31:26:910PM 980218026 Ian Hutchinson Plasma. Similar.

Purge k-side and fill with 20 psi H plus 20 psi D.

Feb 18 1998 03:31:47:630PM 980218027 Ian Hutchinson Plasma

Feb 18 1998 03:49:09:970PM 980218028 Ian Hutchinson Plasma. Some runaways.

Refill k-side with 40 psi D.

Feb 18 1998 04:01:21:210PM 980218029 Ian Hutchinson Plasma. Still not good EDA. Perhaps we need some shots to get rid of H.

Feb 18 1998 04:12:17:150PM 980218030 Ian Hutchinson Plasma. Longer RF pulse before Lmode. Slower impurity accumulation.
Signs of divertor pump-out.

Feb 18 1998 04:25:40:900PM 980218031 Ian Hutchinson Plasma. Not much improvement.

Feb 18 1998 04:38:55:860PM 980218032 Ian Hutchinson Plasma. Similar.

Raise nl04 to 1.1 from .9.

Feb 18 1998 04:48:18:850PM 980218033 Ian Hutchinson Plasma. Disrupts at .38s. A brick.

Feb 18 1998 04:58:47:190PM 980218034 Ian Hutchinson Fizzle.

Br offset to 4.5mT.

Feb 18 1998 05:04:46:330PM 980218035 Ian Hutchinson Plasma. EDA for .4s. Much better heating. But no divertor pump-out worth talking about.
This may be a result of the higher nl04 setting. Substantial Mo.

Engineering Operator Comments

Shot Time Type Status Comment

1 08:34:44:280AM Plasma Ok

2 08:51:05:610AM Plasma Ok

3 09:09:57:300AM Plasma Ok

4 09:21:32:470AM Plasma Ok

5 09:36:43:990AM Plasma Ok

6 09:54:05:070AM Plasma Ok

7 10:18:21:380AM Plasma Ok

8 10:28:52:970AM Plasma Ok

9 10:40:47:430AM Plasma Ok

10 10:51:21:190AM Plasma Ok

11 11:02:52:210AM Plasma Ok

12 11:18:07:070AM Test Ok

13 11:35:40:410AM Test Ok

14 11:49:50:150AM Plasma Ok

15 12:01:26:920PM Plasma Ok

16 12:23:02:130PM Plasma Ok

17 12:38:15:200PM Plasma Ok

18 12:52:38:990PM Plasma Ok

19 01:03:49:400PM Plasma Ok

20 01:13:36:810PM Plasma Ok

21 01:39:33:170PM Plasma Ok

22 01:54:01:210PM Plasma Ok

23 02:09:18:690PM Plasma Ok

24 02:24:26:410PM Plasma Ok

25 02:45:50:100PM Plasma Ok

26 02:58:02:450PM Plasma Ok

27 03:18:11:610PM Plasma Ok

28 03:29:46:150PM Plasma Ok

29 03:47:15:580PM Plasma Ok

30 03:59:58:870PM Plasma Ok

31 04:12:18:940PM Plasma Ok

32 04:24:00:390PM Plasma Ok

33 04:36:18:000PM Plasma Ok

34 04:46:54:630PM Plasma Ok

35 04:57:09:360PM Plasma Ok

Session Leader Comments
Feb 18 1998 08:19:57:360AM		Steve Wukitch	MP189 D(H) Minority and Mode Conversion Heating ------------------------------------------------------------------------------ Engineering setup for 980218: Engineering setup as on 980217007, with TF under HYBRID control Gas setup - fill K-side with 30 PSI of D2, hybrid enable fill B-top with 6 PSI of D2, hybrid enable fill B-side-lower with 1 PSI of Ar, hybrid disable ECDC in He overnight before the run. ECDC in D2 2 hours before the run. (same prescription as over the weekend) Second day after Friday night boronization. RF position feedback is off Gate Valves: ECE PCX (check with Rejean before opening) The goals for today are to: 1. Start with 5.4T fiducial discharges and step up with constant q 5.4T, 0.8 MA, nl_04~1.0, q95~4.5 -- evaluate machine conditions 2. Scan H concentration at 5.4 T, Ip->1.0 MA, 1.25 MW power modulation. -- tentative fill K-side with H/H+D~5% 2 psi of H2 plus 38 PSI of D2, hybrid enable 2 x (5.4 T & 5.1 T, holding q95~constant) H/H+D~10% 4 psi of H2 plus 36 PSI of D2, hybrid enable 2 x (5.4 T & 5.1 T, holding q95~constant) H/H+D~20% 8 psi of H2 plus 32 PSI of D2, hybrid enable 2 x (5.4 T & 5.6 T, holding q95~constant) H/H+D~30% 12 psi of H2 plus 28 PSI of D2, hybrid enable 2 x (5.4 T & 5.7 T, holding q95~constant) H/H+D~40% 16 psi of H2 plus 24 PSI of D2, hybrid enable 2
Feb 18 1998 08:42:48:400AM	980218001	Steve Wukitch	001 plasma early disrupt ~0.32 sec
Feb 18 1998 10:26:08:900AM	980218002	Steve Wukitch	002 plasma EDA 112 kJ H/(H+D)~2% next shot: Ip->1.0 MA
Feb 18 1998 10:26:25:140AM	980218003	Steve Wukitch	003 plasma EDA 189 kJ #1 tripping on voltage limit during modulation H/(H+D)~2%
Feb 18 1998 10:26:45:620AM	980218004	Steve Wukitch	004 plasma EDA 180 kJ #1 tripping on voltage limit during modulation H/(H+D)~2.5%
Feb 18 1998 10:47:18:820AM	980218005	Steve Wukitch	005 plasma EDA 172 kJ #1 tripping on voltage limit during modulation H/(H+D)~2.5%
Feb 18 1998 10:47:42:240AM	980218006	Steve Wukitch	006 plasma EDA 172 kJ finally good modulation H/(H+D)~2.5% next shot: H/H+D mixture to 5%
Feb 18 1998 10:28:59:550AM	980218007	Steve Wukitch	007 55 kA fizzle
Feb 18 1998 10:57:15:730AM	980218008	Steve Wukitch	008 plasma EDA 186 kJ #1: single voltage limit during modulation #2: single voltage limit during startup sawteeth locked to RF modulation after 2-3 cycles H/(H+D) ratio starts at about 15% and slowly comes down to 5% at the end of the shot.
Feb 18 1998 10:49:44:190AM	980218009	Steve Wukitch	009 plasma early disruption -- brick
Feb 18 1998 10:56:58:490AM	980218010	Steve Wukitch	010 fizzle
Feb 18 1998 11:53:33:280AM	980218011	Steve Wukitch	011 plasma EDA 185 kJ good RF modulation sawteeth locked to RF modulation after 2 cycles
Feb 18 1998 11:52:57:750AM	980218014	Steve Wukitch	014 dud
Feb 18 1998 12:16:36:560PM	980218015	Steve Wukitch	015 plasma EDA H/(H+D) ratio starts at about 13% and settles down to 8% towards the end. poor RF modulation
Feb 18 1998 12:51:03:040PM	980218016	Steve Wukitch	016 plasma EDA few voltage faults H/(H+D) ratio starts at about 11% and settles down to 8% towards the end. better RF modulation next shot: 5.1 T
Feb 18 1998 12:51:30:520PM	980218017	Steve Wukitch	017 plasma EDA lots of trips late in modulation BT~5.4T next shot: try 5.1 T again Prf timing: start .55 sec (50 msec delay)
Feb 18 1998 01:06:11:000PM	980218018	Steve Wukitch	018 fizzle
Feb 18 1998 01:06:23:690PM	980218019	Steve Wukitch	019 fizzle
Feb 18 1998 01:28:02:750PM	980218020	Steve Wukitch	020 plasma EDA and goes Elm-free ECE is cutoff sawteeth and RF modulation are NOT locked next shot: back to 5.4 T and 30% H/H+D mixture
Feb 18 1998 02:21:39:030PM	980218021	Steve Wukitch	021 plasma EDA lousy RF H/(H+D) ratio starts at about 18% and settles down to 10% towards the end. Ti from neutrons with H/H+D~ 14%
Feb 18 1998 02:21:56:370PM	980218022	Steve Wukitch	022 plasma EDA H/(H+D) ratio starts at about 19% and settles down to 12% towards the end. Ti from neutrons with H/H+D~ 15.5% next shot: lowered the RF power
Feb 18 1998 02:22:26:730PM	980218023	Steve Wukitch	023 plasma EDA modulation is better next shot: BT->5.1
Feb 18 1998 03:00:43:640PM	980218024	Steve Wukitch	024 plasma multiple EDA/EF H/(H+D) ratio starts at about 22% and settles down to 15% towards the end. Ti from neutrons with H/H+D~ 18.5% next shot: BT->5.4T
Feb 18 1998 03:02:37:660PM	980218025	Steve Wukitch	025 plasma multiple EDA/EF signs of MC on central GPC_1 channels next shot: repeat
Feb 18 1998 03:05:00:540PM	980218026	Steve Wukitch	026 plasma multiple EDA/EF signs of MC on central GPC_1 channels next shot: increase H/H+D~50% in plenum
Feb 18 1998 03:44:00:120PM	980218027	Steve Wukitch	027 plasma multiple EDA/EF various faults on RF -- some useable signs of MC further off-axis H/(H+D) ratio starts at about 30% and settles down to 25% towards the end. Ti from neutrons with H/H+D~27.5%
Feb 18 1998 03:46:34:510PM	980218028	Steve Wukitch	028 plasma multiple EDA/EF various faults on RF -- modulation is in L-mode signs of MC further off-axis H/(H+D) ratio starts at about 32% and settles down to 24% towards the end. next shot: plenum is D only; NO H mixed in plenum
Feb 18 1998 04:13:09:980PM	980218029	Steve Wukitch	029 plasma multiple H-modes/L-mode only one RF trip on #2 H/(H+D) ratio starts at about 17% and settles down to 21% towards the end.
Feb 18 1998 04:15:08:500PM	980218030	Steve Wukitch	030 plasma multiple H-modes/L-mode H/(H+D) ratio starts at about 14% and settles down to 17% towards the end.
Feb 18 1998 04:21:38:410PM	980218031	Steve Wukitch	031 plasma multiple H-modes #1 screen overcurrent H/(H+D) ratio starts at about 12% and settles down to 16% towards the end. (up)
Feb 18 1998 04:49:24:790PM	980218032	Steve Wukitch	032 plasma multiple H-modes H/(H+D) ratio starts at about 11% and settles down to 12% towards the end. (up) Ti from neutrons with H/H+D~11.5% next shot: no modulation and raise power by ~200 kW and 20% increase of nl_04. 608 408 2527 962
Feb 18 1998 04:49:57:790PM	980218033	Steve Wukitch	033 plasma early disruption
Feb 18 1998 04:50:19:030PM	980218034	Steve Wukitch	034 fizzle
Feb 18 1998 05:08:55:790PM	980218035	Steve Wukitch	035 plasma EDA H/(H+D) ratio starts at about 9% and settles down to 11% towards the end. (up)

Physics Operator Comments
Feb 18 1998 08:33:28:970AM		Ian Hutchinson	MP 189 Minority-Mode Conversion D-H heating. Overnight ECDC in Helium till 2.05. Then 2 hours of D2 ECDC. Load from 980217007. EF4 to -1340A.
Feb 18 1998 08:51:01:230AM	980218001	Ian Hutchinson	Plasma. Disrupts at .3s. A vertical position problem. Get magnetics error messages. Reply received on PHYSOP from user MDSSERVER at BAROLO Batch 08:37:28 \mag_bp_coils.signals:bp26_bc has a baseline offset -2.7E-02 Reply received on PHYSOP from user MDSSERVER at BAROLO Batch 08:37:28 \mag_bp_coils.signals:bp23_bc has a baseline offset -7.4E-01 Seems that bp23_bc is being used and has a problem. This seems to have occurred on shot 35 yesterday. The coil appears to have come back from the dead at the disruption today.
Feb 18 1998 09:11:47:110AM	980218002	Ian Hutchinson	Repeat. Plasma. Coil seems to have fixed itself. Some runaways, like previous. Load shot 22. It is running in segment 3. EF4 to -1335. Gas fill puff to 16ms, from 14. Enable Argon. (20ms).
Feb 18 1998 09:22:59:830AM	980218003	Ian Hutchinson	Plasma. Longish H-mode. Injection at .85s causes plasma to become more ELM-free. RF trips later.
Feb 18 1998 09:33:39:210AM	980218004	Ian Hutchinson	Plasma. Still significant radiation. zcur to -1.2cm from -1.5
Feb 18 1998 09:52:23:210AM	980218005	Ian Hutchinson	Plasma. zcur to -1 cm.
Feb 18 1998 10:20:02:760AM	980218006	Ian Hutchinson	Plasma. RF folks are satisfied. Argon puff to 16ms from 12ms. I think I looked in the wrong segment before. 2psi H +38psi D into K-side (pg 3, main gas puff). Invrease pg3 V to 50V prior to .2s.
Feb 18 1998 10:37:42:850AM	980218007	Ian Hutchinson	25minute break for gas change to 5% H. Plasma 55kA and dies at 18ms. Br has drifted up about mT. Br offset to 4.5mT from 5mT.
Feb 18 1998 10:42:11:480AM	980218008	Ian Hutchinson	Plasma. No changes.
Feb 18 1998 10:52:51:180AM	980218009	Ian Hutchinson	Plasma Disrupts at .497s. Brick at .48s.
Feb 18 1998 11:04:19:780AM	980218010	Ian Hutchinson	Fizzle. 40kA dies at 13ms. A very early breakdown. Br a tad negative. Bz also low. Ef4 to -1330 from -1335A
Feb 18 1998 11:26:16:880AM	980218011	Ian Hutchinson	Plasma. OH2U coax resitance warning. 1.01 uohm. Replace K-side with 4psi H plus 36 psi D. Do Tuesday test.
Feb 18 1998 11:35:09:600AM	980218012	Ian Hutchinson	Tuesday test. OH2 resistance remains at .8 uohm. Rather high. Cooling in a different mode for about 12min. Another.
Feb 18 1998 11:46:01:300AM	980218013	Ian Hutchinson	No significant change in resistance. Go for full plasma on next shot.
Feb 18 1998 12:01:41:630PM	980218014	Ian Hutchinson	Dud. Granetz substituting as physop for Ian until 13:00 MFLUX INIT scope looks identical to last plasma shot (011). Gas pressure okay. Next shot: just try again, no changes
Feb 18 1998 12:11:40:620PM	980218015	Ian Hutchinson	Plasma. OH2U coax resistance is 0.9 uohm. RF had troubles after 0.9 s. Next shot: repeat, no PCS changes.
Feb 18 1998 12:31:06:170PM	980218016	Ian Hutchinson	Plasma. RF did better. Next shot: reduce toroidal field to 5.1 T (141kA).
Feb 18 1998 12:46:01:300PM	980218017	Ian Hutchinson	Plasma. Btor did not change. Operator error: segment 3 is being used instead of segment 2. Next shot: reduce Btor to 5.1 T in segment 3 also. Increase argon puff to 20 ms in segment 3.
Feb 18 1998 01:02:24:180PM	980218018	Ian Hutchinson	Fizzle. Br looks a tiny bit high. Btor = 5.15 T. Next shot: reduce Br offset from 0.0045 to 0.0040 T. Reduce I_TF by another 1 kA.
Feb 18 1998 01:10:32:310PM	980218019	Ian Hutchinson	Fizzle. Two in a row. Next shot: Change IC_EF4 from -1330 to -1340 amps.
Feb 18 1998 01:41:42:550PM	980218020	Ian Hutchinson	Plasma. Ian returns as physop. Gas mix to 12psi H plus 28psi D. Import segment 3 from shot 16 to return to 5.4T. Load.
Feb 18 1998 01:55:25:060PM	980218021	Ian Hutchinson	Plasma. zxl to -1.2cm from -1.5cm.
Feb 18 1998 02:14:03:870PM	980218022	Ian Hutchinson	Plasma. zxl to -1cm. Argon to 19ms.
Feb 18 1998 02:35:26:450PM	980218023	Ian Hutchinson	Plasma. Bt to 142kA.
Feb 18 1998 02:52:36:680PM	980218024	Ian Hutchinson	Plasma. I notice that this has almost no divertor pump out during the H-mode phase. It has a lot of impurity accumulation and is much less EDAish in character. Looking back at shots today, there is, it seems quite a good correlation between divertor pumpout and EDA character. Bt to 150kA.
Feb 18 1998 03:00:04:120PM	980218025	Ian Hutchinson	Plasma. No pumpout.
Feb 18 1998 03:31:26:910PM	980218026	Ian Hutchinson	Plasma. Similar. Purge k-side and fill with 20 psi H plus 20 psi D.
Feb 18 1998 03:31:47:630PM	980218027	Ian Hutchinson	Plasma
Feb 18 1998 03:49:09:970PM	980218028	Ian Hutchinson	Plasma. Some runaways. Refill k-side with 40 psi D.
Feb 18 1998 04:01:21:210PM	980218029	Ian Hutchinson	Plasma. Still not good EDA. Perhaps we need some shots to get rid of H.
Feb 18 1998 04:12:17:150PM	980218030	Ian Hutchinson	Plasma. Longer RF pulse before Lmode. Slower impurity accumulation. Signs of divertor pump-out.
Feb 18 1998 04:25:40:900PM	980218031	Ian Hutchinson	Plasma. Not much improvement.
Feb 18 1998 04:38:55:860PM	980218032	Ian Hutchinson	Plasma. Similar. Raise nl04 to 1.1 from .9.
Feb 18 1998 04:48:18:850PM	980218033	Ian Hutchinson	Plasma. Disrupts at .38s. A brick.
Feb 18 1998 04:58:47:190PM	980218034	Ian Hutchinson	Fizzle. Br offset to 4.5mT.
Feb 18 1998 05:04:46:330PM	980218035	Ian Hutchinson	Plasma. EDA for .4s. Much better heating. But no divertor pump-out worth talking about. This may be a result of the higher nl04 setting. Substantial Mo.

Engineering Operator Comments
Shot	Time	Type	Status	Comment
1	08:34:44:280AM	Plasma	Ok
2	08:51:05:610AM	Plasma	Ok
3	09:09:57:300AM	Plasma	Ok
4	09:21:32:470AM	Plasma	Ok
5	09:36:43:990AM	Plasma	Ok
6	09:54:05:070AM	Plasma	Ok
7	10:18:21:380AM	Plasma	Ok
8	10:28:52:970AM	Plasma	Ok
9	10:40:47:430AM	Plasma	Ok
10	10:51:21:190AM	Plasma	Ok
11	11:02:52:210AM	Plasma	Ok
12	11:18:07:070AM	Test	Ok
13	11:35:40:410AM	Test	Ok
14	11:49:50:150AM	Plasma	Ok
15	12:01:26:920PM	Plasma	Ok
16	12:23:02:130PM	Plasma	Ok
17	12:38:15:200PM	Plasma	Ok
18	12:52:38:990PM	Plasma	Ok
19	01:03:49:400PM	Plasma	Ok
20	01:13:36:810PM	Plasma	Ok
21	01:39:33:170PM	Plasma	Ok
22	01:54:01:210PM	Plasma	Ok
23	02:09:18:690PM	Plasma	Ok
24	02:24:26:410PM	Plasma	Ok
25	02:45:50:100PM	Plasma	Ok
26	02:58:02:450PM	Plasma	Ok
27	03:18:11:610PM	Plasma	Ok
28	03:29:46:150PM	Plasma	Ok
29	03:47:15:580PM	Plasma	Ok
30	03:59:58:870PM	Plasma	Ok
31	04:12:18:940PM	Plasma	Ok
32	04:24:00:390PM	Plasma	Ok
33	04:36:18:000PM	Plasma	Ok
34	04:46:54:630PM	Plasma	Ok
35	04:57:09:360PM	Plasma	Ok