Alcator C-Mod Run 980217 Information

Miniproposals

Miniproposal: 133

Date Filed: 12/8/1995

Title: Boronization of Alcator C-Mod

First Author: Jim Terry

Session Leader: Steve Wolfe (shots 1-10)

Miniproposal: 155

Date Filed: 7/15/1996

Title: H-Mode Confinement Scaling MP No. 155

First Author: Martin Greenwald

Session Leader: Martin Greenwald (shots 11-36)

Operators
Session leader(s):	Steve Wolfe,Martin Greenwald
Physics operator(s):	Earl Marmar
Engineering operator(s):	Frank Silva,Bill Cochran,Vinny Bertolino

Engineering Operator Run Comment
MP 133 and MP155 wolfe,marmar,cochran,silva,bertolino

Session Leader Plans

Physics Operators Plans

Session Leader Summaries

Entered: Jul 7 2004 03:49:18:227PM

Author: To Be Determined

Run Summary for first part of 980217

MP: 133 Post-Boronization (sort of)
SL: Wolfe
PO: Marmar
EO: Cochran

Run Plan:
---------
Run fiducials until reasonably reproducible startup and plasma operation is
regained. Try adjusting pre-puff to compensate for wall pumping, if
significant. If sufficiently frustrated by lack of startup, run some
additional D2 ECDC.

Once fiducials look ok, run some 1MA discharges like 980210025-26.

Then turn the run over to Greenwald for confinement scaling.

Results:
--------
Recovery (or whatever you would call it) from boronization was much quicker
today than previous experience. After ten plasma attempts, and six plasmas, we
were back to good plasma conditions in terms of startup and H-mode quality.

There was a delay in getting the alternator warm, so the first shot did not
happen until about 10:00 AM. After the usual Tuesday test, plasma attempts
started on shot 2. All of theses shots had small amounts of Argon.

Shots 2-4 were fizzles; Earl tweaked both gas and Br.

Shot 5-7 were good fiducials, with reasonable H-modes, getting up to 115kJ and
1.3e13 netrons/sec. We then moved on to the 1MA shots.

Shot 8 and 10 were supposed to be like 980210025; 8 had injections and got to
160kJ, 10 was somewhat better and got to 200kJ. (#9 fizzled, and #10 had
decreased pre-puff).

Shot 11 had decreased argon and increased target density up to nl4=0.9e20. The
neutron rate went to 7.5e13 neut/sec, and the stored energy again was up to
200kJ. Martin's scope indicated H=2 assuming 90% RF absorption.

After shot 11, we declared the machine ready for primetime, and turned over to
Martin to begin the confinement scaling experiments at 12:05.

Entered: Jul 7 2004 03:49:18:240PM

Author: To Be Determined

Run Summary for 980217
Triangularity Scan MP 155

Session Leader: Greenwald
Phys Op: Marmar

============================

Plan:

We want to look at the scaling with Bt, P, and kappa

The first half of the run is dedicated to post-boron conditioning,
we should start with fiducials until we get good h-modes.

It's probably easiest to start the confinement scans with the power
scaling, at parameters where the RF can get the maximum power and
also where there is the most room between the L/H threshold and that
max power. I think this argues for running at .8 MA and moderately
low density, nl_04 ~ 1. The shape can be our normal shape.

The next scan would be with kappa, from the lowest value consistent
with a divertor configuration and decent RF coupling to the highest
value consistent with axisymetric stability. Perhaps kappa = 1.45 ->
1.75 The RF power can be nominal ~ 2.5 MW or slightly less if that
helps for the lowest kappa. Ip = 1 MA would probably help to get
higher kappas, q95 would be around 3 at the lowest kappas.

If time permits we would scan Bt consistent with minority heating at
r/a < .5, that is Bt = 4.5 -> 6.1. This would be with our normal
shape, Ip = 1MA and Prf ~ 2.5 MW.

==============================

Results:

An excellent run, we achieved record stored energies, normalized
betas, and neutron rates (980217015). Wmhd = 0.233 MJ, H = 2.4,
betaNormal = 1.6, Rdd = 1.5e14, prad/ptot ~ .3. Core conditions were
quite similar to 960116, though the neutral/divertor behavior is
still different. Wukitch estimates the absorbed RF fraction at about
0.8

The first part of the run was dedicated to post-boronization
conditioning, by noon the conditioning was finished and physics
began. There were more fizzles than normal, but we got about
half a days work done - we can probably count on this for the
future.

The H-modes were EDA all day, no attempt to get ELMfree was
attempted, though these likely would show even better performance.

Most of the afternoon was dedicated to a power scan in EDA H-mode.
We got from 2.0 to 4.1 MW of total power. Stored energy increased
faster than sqrt(ptot) ranging from 0.13 to 0.23 MJ. At the lowest
powers the discharges became less EDA like (more like ELMfree) as
determined from Halpha, xray pedestal width, density rise, and
impurity accumulation. Since EDA has generally been found to have
slightly lower confinement, this is in the opposite direction to
explain the somewhat surprising power scan results.

This may be evidence for dependence of confinement on proximity to
the threshold. P/nBS varied from .015 to .025 over the power scan as
the H factor rose from 1.7 - 2.4. This is somewhat in contradiction
to the 96 data, but doesn't lie outside the scatter in that data
set.

We were able to perform a modest kappa scan - from 1.5-1.7. No
change in confinement was observed. Because of the small range
of the scan, we can rule out only a very strong dependence on kappa.

================================

Shots suitable for further analysis include:

Shot Ptot
980217011 3.5
980217012 3.7
980217013 3.7
980217015 4.1
980217020 3.7
980217022 3.3
980217024 2.9
980217025 2.5
980217026 2.2
980217027 2.0 kappa
980217028 3.4 1.68
980217029 3.3 1.63
980217031 3.1 1.6
980217033 3.2 1.58
980217034 3.0 1.51

Physics Operator Summaries

Entered: Jul 7 2004 04:36:59:537PM

Author: To Be Determined

MP133 Post-Boronization
MP155 Confinement Scaling
SL: Wolfe/Greenwald
PO: Marmar
EO: Cochrane, Bertolino

Boronization was completed on Saturday morning.
He ECDC until early this morning, then switch over to D2 for two hours.

_________________________
Plan for 980217:

Start with standard Tuesday OH test, except: Enable B-top valve for hybrid
puff during test shot.

Run fiducials until reasonably reproducible startup and plasma operation is
regained. Try adjusting pre-puff to compensate for wall pumping, if
significant. If sufficiently frustrated by lack of startup, run some
additional D2 ECDC.

Once fiducials look ok, run some 1MA discharges like 980210025-26.

Then begin MP155: Confinement scaling, with Martin as SL.

_________________________
Results:

The fiducial part of the run went reasonably well, and the 1 MA plasmas got
into record territory (shot 15 had neutron rate ~ 1.5e14 and E_tot>.23MJ).

We got some of the confinement scaling (power and kappa) accomplished, although
running at low kappa is not easy: the strikes were close to the noses on the
shot (#34), which reached kappa=1.5, and after the EF2_lower current went to
zero, vertical stability was eventually lost.

Fizzles were a problem (as we have seen immediately post-boronization). Lowering
the fill pressure after the first good shot may have helped somewhat. The
fizzle-dud sequence (16 through 19) was probably due to the fact that B_z had
drifted out of range at breakdown time; an EF4 tweak fixed this (as suggested
by Ian, Wolfe and Goetz).

36 cycles = 21 plasma + 1 test + 12 fizzles + 2 duds

no power supply or data system problems today.

1. OH test

2. Loaded from 980210004
B_R offset to .0045 from .005T
prepuff to 17 msec from 14 msec
enable argon
fizzle; B_R a little negative.

3. B_R offset to .0055 from .0045 T
fizzle

4. prepuff to 15 ms from 17; fizzle; B_R now looks slightly positive

5. B_R offset to .005 from .0055; plasma;

6. reduce prepuff to 13 ms; plasma;

7. no changes; plasma

8. go to 1 MA; load segment 3 from 980210025; increase Argon puff to 14 msec from 10; plasma

9. reduce Argon to 10 msec; fizzle

10. reduce prepuff to 12 msec from 13; plasma

11. reduce argon from 10 to 9 msec; raise nl_04 from 7e19 to 9e19; adjust pulse gas preprog voltage;
plasma

12. RF turn-on earlier; no PCS changes; plasma

13. slightly more RF power; plasma

14. argon to 11 msec from 9; fizzle; late breakdown

15. B_R offset to .0045 from .005 T; plasma

16. no changes; dud

17. increase prepuff to 14 ms from 12 ms; fizzle; B_R looks a bit negative.

18. B_R offset to .005 from .0045 T; fizzle

19. prepuff to 12 msec from 14 msec; dud

20. prefill to 16 msec from 12 msec; EF4 15 Amp more negative at t=0.; plasma

21. no changes; fizzle

22. prepuff to 14; plasma

23. no changes; fizzle

24. prepuff to 13 msec; plasma

25. 5 Amp more negative on EF4; plasma

26. no changes; plasma

27. no pcs changes; plasma

28. lower ZXU 1 cm
lower ZCUR 1 cm
plasma; big radiated power increase after 1 second.
kappa=1.64

29. plasma

30. zxl up 1.5 cm
zcur up .5 cm
zxu up 1cm
fizzle

31. no further changes from 29; plasma

32. zxl up 1 cm; fizzle

33. B_r offset to .0045 from .005 T
Prepuff to 12 ms from 13 ms
plasma; disrupt in rampdown at .6MA

34. ZXL up 1 cm
ZCURR down 4 mm
plasma
disrupt at 1.15 s, near end of flattop
EF2_lower went to 0 at about .74 seconds

35. reload seg 3 from shot 24
lower nl_04 demand to 7e19
fizzle
B_R looks a bit negative

36. B_r offset to .005 from .0045 T
plasma
disrupt at .32 seconds; something fell in?

Session Leader Comments

Feb 17 1998 08:07:46:730AM Steve Wolfe MP133 Post-Boronization
SL: wolfe
PO: marmar

Boronization was completed on Saturday morning.
He ECDC until early this morning, then switch over to D2 for two hours.

Plan for first part of 980217:
-------------------------
Start with standard Tuesday OH test, except: Enable B-top valve for hybrid
puff during test shot.

Run fiducials until reasonably reproducible startup and plasma operation is
regained. Try adjusting pre-puff to compensate for wall pumping, if
significant. If sufficiently frustrated by lack of startup, run some
additional D2 ECDC.

Once fiducials look ok, run some 1MA discharges like 980210025-26.

Then begin MP155: Confinement scaling, with Martin as SL.
-

Feb 17 1998 08:58:54:550AM Steve Wolfe 08:57 Turned on Ratiomatics

Feb 17 1998 12:19:08:060PM Martin Greenwald mp 155 hmode confinement scaling

Session Leader - Greenwald
Phys Op - Marmar

We want to look at the scaling with Bt, P, and kappa

The run should start with fiducials until we get good h-modes.

It's probably easiest to start the confinement scans with the
power scaling, at parameters where the RF can get the maximum
power and also where there is the most room between the L/H
threshold and that max power. I think this argues for running at
1.0 MA and moderately low density, nl_04 ~ 1. The shape can be our
normal shape.

The next scan would be with kappa, from the lowest value
consistent with a divertor configuration and decent RF coupling to
the highest value consistent with axisymetric stability. Perhaps
kappa = 1.45 -> 1.75 The RF power can be nominal ~ 2.5 MW or
slightly less if that helps for the lowest kappa. Ip = 1 MA would
probably help to get higher kappas, q95 would be around 3 at the
lowest kappas.

If time permits we would scan Bt consistent with minority heating
at r/a < .5, that is Bt = 4.5 -> 6.1. This would be with our
normal shape, Ip = 1MA and Prf ~ 2.5 MW.

Feb 17 1998 10:06:13:280AM 980217001 Steve Wolfe shot 1: Tueday oh test. Ratiomatic says .045mTorr, a bit on the low side.

Feb 17 1998 10:12:59:210AM 980217002 Steve Wolfe shot 2: plasma attempt. fizzle. early bd (3msec), br=-.001.

Feb 17 1998 10:23:09:860AM 980217003 Steve Wolfe shot 3: br tweak. fizzle.

Feb 17 1998 10:33:09:840AM 980217004 Steve Wolfe shot 4: gas tweak. fizzle.

Feb 17 1998 10:40:06:430AM 980217005 Steve Wolfe shot 5: br tweak (back to .005) plasma.
2 hmodes. 1 injection. 110kJ.

Feb 17 1998 10:51:35:550AM 980217006 Steve Wolfe shot 6: Drop the pre-puff, trying to outguess (if not outgas) the plasma.
plasma - Two in a row!
one long h-mode. 250kW on 2pi, and no step at 2nd RF increment. 115kJ. 1.3e13neut/sec

Feb 17 1998 11:17:12:750AM 980217007 Steve Wolfe shot 7: plasma. Three in a row.
1h-mode, 115kJ, 1.3e13 n/sec.

Looks good. Next shot, 1MA like 980210025.

Feb 17 1998 11:27:12:710AM 980217008 Steve Wolfe shot 8: plasma.
1 h-mode, EDA, 1 trip. between 2 and 3e13n/sec. ; 160kJ.
2 injections, .91sec and 1.03 sec.

Feb 17 1998 11:33:41:130AM 980217009 Steve Wolfe shot 9: reduce the Argon. tune the rf. fizzle.

Feb 17 1998 01:18:38:920PM 980217010 Steve Wolfe shot 10: decrease pre-puff "just slightly".
reduce the Argon. tune the rf.

plasma. Early injection almost kills it, rf dropout at 1.04 kills the h-mode for a moment.
199.99kJ, 7.e13 n/sec.

rf tripped on voltage limit.

Feb 17 1998 12:05:11:240PM 980217011 Steve Wolfe shot 11: Increase target density to .9e20 (from .7e20).
plasma, rf ran through, up to 2.9MW.
7.5e13n/sec, increasing through pulse. 198kJ. Martin says H=2 with 90% absorption.

Feb 17 1998 12:17:04:740PM 980217011 Martin Greenwald Good Shot

EDA
H = 2 assuming f_rf = .9 (SW measures .8)

Ip = 1.0 MA
Bt = 5.4
ne target = 1.6
nemax = 3.7
div press = 30 mT
kappa = 1.68
Ptot = 3.5

Feb 17 1998 12:24:10:660PM 980217012 Martin Greenwald
Good Shot

H-mode type:

Bt = 5.4
Ip = 1.0
kappa = 1.68
Ptot = 3.7

ne target = 1.6
nemax = 3.8
div n0 = 26
div n0 max = 40
prad/ptot = .33
Wmhd = .189
H = 1.9 (w frf assumed = .8)

Feb 17 1998 12:50:25:320PM 980217013 Martin Greenwald
Good Shot

H-mode type:

Bt = 5.4
Ip = 1
kappa = 1.67
Ptot = 3.7

ne target = 1.6
nemax = 3.9
div n0 = 30
div n0 max = 37
prad/ptot = .26
Wmhd = .215
H = 2.3 (w frf assumed = .8)

Feb 17 1998 12:49:31:820PM 980217014 Martin Greenwald fizzle

Feb 17 1998 01:01:17:170PM 980217015 Martin Greenwald
Good Shot

H-mode type:

Bt = 5.4
Ip = 1
kappa = 1.68
Ptot = 4.1

ne target = 1.5
nemax = 3.7
div n0 = 29
div n0 max =
prad/ptot = .4
Wmhd = .233
H = 2.5 (w frf assumed = .8)

Feb 17 1998 01:11:18:670PM 980217016 Martin Greenwald Fizzle

Feb 17 1998 01:24:05:320PM 980217017 Martin Greenwald Fizzle

Feb 17 1998 01:35:52:850PM 980217018 Martin Greenwald
fizzle

Feb 17 1998 01:43:07:150PM 980217019 Martin Greenwald Dud

Feb 17 1998 01:59:50:030PM 980217020 Martin Greenwald OK shot, lots of RF trips

H-mode type: EDA

Bt = 5.4
Ip = 1
kappa = 1.68
Ptot = 3.7

ne target = 1.5
nemax = 3.7
div n0 = 30
div n0 max = 25
prad/ptot = .3
Wmhd = 0.2
H = 2.2 (w frf assumed = .8)

Feb 17 1998 02:04:59:410PM 980217021 Martin Greenwald Fizzle

Feb 17 1998 02:21:25:270PM 980217022 Martin Greenwald
Good Shot

H-mode type:

Bt = 5.4
Ip = 1
kappa = 1.68
Ptot = 3.3

ne target = 1.5
nemax = 3.6
div n0 = 30
div n0 max = 29
prad/ptot = .25
Wmhd = .19
H = 2.1 (w frf assumed = .8)

Feb 17 1998 02:27:54:090PM 980217023 Martin Greenwald Fizzle

Feb 17 1998 02:48:54:310PM 980217024 Martin Greenwald
Good Shot

H-mode type:

Bt = 5.4
Ip = 1
kappa = 1.68
Ptot = 2.9

ne target = 1.5
nemax = 3.5
div n0 = 25
div n0 max = 20
prad/ptot = .3
Wmhd = .162
H = 1.8 (w frf assumed = .8)

Feb 17 1998 02:54:54:850PM 980217025 Martin Greenwald
Good Shot

H-mode type: EDA, but with mildly accumulating impurities

Bt = 5.4
Ip = 1
kappa = 1.68
Ptot = 2.5

ne target = 1.5
nemax = 3.5
div n0 = 34
div n0 max = 27
prad/ptot = .45
Wmhd = .14
H = 1.8 (w frf assumed = .8)

Feb 17 1998 03:13:31:250PM 980217026 Martin Greenwald
Good Shot

H-mode type:

Bt = 5.4
Ip = 1
kappa = 1.68
Ptot = 2.2

ne target = 1.5
nemax = 3.5
div n0 = 25
div n0 max = 25
prad/ptot = .5
Wmhd = .128
H = 1.7 (w frf assumed = .8)

Feb 17 1998 03:19:50:350PM 980217027 Martin Greenwald
Good Shot

H-mode type: EDA with some ELMfree character

Bt = 5.4
Ip = 1
kappa = 1.68
Ptot = 2.0

ne target = 1.5
nemax = 3.6
div n0 = 30
div n0 max = 20
prad/ptot = .6
Wmhd = .13
H = 1.7 (w frf assumed = .8)

Feb 17 1998 03:34:16:560PM 980217028 Martin Greenwald
Good Shot

H-mode type: EDA

Bt = 5.4
Ip = 1
kappa = 1.68
Ptot = 3.4

ne target = 1.5
nemax = 3.6
div n0 = 25
div n0 max = 25
prad/ptot = .35
Wmhd = .2
H = 2.1 (w frf assumed = .8)

Feb 17 1998 03:46:37:810PM 980217029 Martin Greenwald
Good Shot EDA, goes limited at about 1 sec

H-mode type:

Bt = 5.4
Ip = 1
kappa = 1.63
Ptot = 3.3

ne target = 1.5
nemax = 3.7
div n0 = 28
div n0 max = 15
prad/ptot = .28
Wmhd = .17
H = 1.8 (w frf assumed = .8)

Feb 17 1998 03:56:15:790PM 980217030 Martin Greenwald Fizzle

Feb 17 1998 04:10:41:660PM 980217031 Martin Greenwald
Good Shot

H-mode type: EDA, some sort of problem develops at .9 sec

Bt = 5.4
Ip = 1
kappa = 1.6
Ptot = 3.1

ne target = 1.5
nemax = 3.7
div n0 = 20
div n0 max = 15
prad/ptot = .4
Wmhd = .2
H = 2.3 (w frf assumed = .8)

Feb 17 1998 04:18:57:980PM 980217032 Martin Greenwald fizzle

Feb 17 1998 04:34:02:180PM 980217033 Martin Greenwald
Good Shot

H-mode type: EDA

Bt = 5.4
Ip = 1
kappa = 1.58
Ptot = 3.2

ne target = 1.5
nemax = 3.5
div n0 = 18
div n0 max = 10
prad/ptot = .3
Wmhd = .19
H = 2.1 (w frf assumed = .8)

Feb 17 1998 04:50:00:660PM 980217034 Martin Greenwald
OK Shot, but disruption at 1.1 sec

H-mode type:

Bt = 5.4
Ip = 1
kappa = 1.53
Ptot = 3 MW

ne target = 1.6
nemax = 3.3
div n0 = 18
div n0 max = 10
prad/ptot = .2
Wmhd = .18
H = 2.1 (w frf assumed = .8)

Feb 17 1998 04:58:43:100PM 980217035 Martin Greenwald Fizzle

Feb 17 1998 05:04:48:460PM 980217036 Martin Greenwald Early Disruption

Physics Operator Comments

Feb 17 1998 10:13:39:680AM 980217002 Earl Marmar Loaded from 980210004
B_R offset to .0045 from .005T
prepuff to 17 msec from 14 msec
enable argon

fizzle; B_R a little negative.

Feb 17 1998 10:22:24:640AM 980217003 Earl Marmar B_R offset to .0055 from .0045 T
fizzle

Feb 17 1998 10:31:22:780AM 980217004 Earl Marmar prepuff to 15 ms from 17; fizzle; B_R now looks slightly positive

Feb 17 1998 10:43:38:090AM 980217005 Earl Marmar B_R offset to .005 from .0055; plasma;

Feb 17 1998 10:52:37:140AM 980217006 Earl Marmar reduce prepuff to 13 ms; plasma;

Feb 17 1998 11:16:10:370AM 980217007 Earl Marmar no changes; plasma

Feb 17 1998 11:19:55:870AM 980217008 Earl Marmar go to 1 MA; load segment 3 from 980210025; increase Argon puff to 14 msec from 10; plasma

Feb 17 1998 11:32:00:270AM 980217009 Earl Marmar reduce Argon to 10 msec; fizzle

Feb 17 1998 11:47:13:020AM 980217010 Earl Marmar reduce prepuff to 12 msec from 13; plasma

Feb 17 1998 12:01:51:070PM 980217011 Earl Marmar reduce argon from 10 to 9 msec; raise nl_04 from 7e19 to 9e19; adjust pulse gas preprog voltage;
plasma

Feb 17 1998 12:18:55:250PM 980217012 Earl Marmar RF turn-on earlier; no PCS changes; plasma

Feb 17 1998 12:35:26:530PM 980217013 Earl Marmar slightly more RF power; plasma

Feb 17 1998 12:48:48:140PM 980217014 Earl Marmar argon to 11 msec from 9; fizzle; late breakdown

Feb 17 1998 01:13:08:020PM 980217015 Earl Marmar B_R offset to .0045 from .005 T; plasma

Feb 17 1998 01:13:24:260PM 980217016 Earl Marmar no changes; dud

Feb 17 1998 01:25:53:510PM 980217017 Earl Marmar increase prepuff to 14 ms from 12 ms; fizzle; B_R looks a bit negative.

Feb 17 1998 01:35:37:670PM 980217018 Earl Marmar B_R offset to .005 from .0045 T; fizzle

Feb 17 1998 01:43:37:020PM 980217019 Earl Marmar prepuff to 12 msec from 14 msec; dud

Feb 17 1998 02:01:18:170PM 980217020 Earl Marmar prefill to 16 msec from 12 msec; EF4 15 Amp more negative at t=0.; plasma

Feb 17 1998 02:07:05:230PM 980217021 Earl Marmar no changes; fizzle

Feb 17 1998 02:22:18:550PM 980217022 Earl Marmar prepuff to 14; plasma

Feb 17 1998 02:29:12:680PM 980217023 Earl Marmar no changes; fizzle

Feb 17 1998 02:37:15:610PM 980217024 Earl Marmar prepuff to 13 msec; plasma

Feb 17 1998 06:13:40:720PM 980217025 Earl Marmar 5 Amp more negative on EF4; plasma

Feb 17 1998 03:06:50:150PM 980217026 Earl Marmar no changes; plasma

Feb 17 1998 03:13:53:660PM 980217027 Earl Marmar no pcs changes; plasma

Feb 17 1998 03:59:01:670PM 980217029 Earl Marmar lower ZXU 1 cm
lower ZCUR 1 cm

plasma; big radiated power increase after 1 second.
kappa=1.64

Feb 17 1998 03:56:54:380PM 980217030 Earl Marmar zxl up 1.5 cm
zcur up .5 cm
zxu up 1cm

fizzle

Feb 17 1998 04:15:15:860PM 980217031 Earl Marmar no further changes from 29; plasma

Feb 17 1998 04:20:39:030PM 980217032 Earl Marmar zxl up 1 cm; fizzle

Feb 17 1998 04:39:23:230PM 980217033 Earl Marmar B_r offset to .0045 from .005 T
Prepuff to 12 ms from 13 ms
plasma; disrupt in rampdown at .6MA

Feb 17 1998 04:50:58:740PM 980217034 Earl Marmar ZXL up 1 cm
ZCURR down 4 mm

plasma
disrupt at 1.15 s, near end of flattop
EF2_lower went to 0 at about .74 seconds

Feb 17 1998 04:59:37:510PM 980217035 Earl Marmar reload seg 3 from shot 24
lower nl_04 demand to 7e19
fizzle
B_R looks a bit negative

Feb 17 1998 05:09:44:830PM 980217036 Earl Marmar B_r offset to .005 from .0045 T

disrupt at .32 seconds; something fell in?

Engineering Operator Comments

Shot Time Type Status Comment

1 09:52:56:810AM Test Ok coax test shot ok

2 10:07:45:020AM Plasma Ok

3 10:16:25:500AM Plasma Ok

4 10:25:00:900AM Plasma Ok

5 10:33:46:620AM Plasma Ok

6 10:44:57:820AM Plasma Ok

7 11:00:06:430AM Plasma Ok

8 11:18:10:360AM Plasma Ok

9 11:30:21:020AM Plasma Ok

10 11:39:38:000AM Plasma Ok

11 11:54:48:990AM Plasma Ok

12 12:13:09:940PM Plasma Ok

13 12:28:16:420PM Plasma Ok

14 12:43:38:810PM Plasma Ok

15 12:54:11:390PM Plasma Ok

16 01:09:31:680PM Plasma Ok

17 01:21:10:560PM Plasma Ok

18 01:31:47:540PM Plasma Ok

19 01:40:52:490PM Plasma Ok

20 01:50:26:070PM Plasma Ok

21 02:03:08:300PM Plasma Ok

22 02:12:27:360PM Plasma Ok

23 02:25:27:790PM Plasma Ok

24 02:35:20:800PM Plasma Ok

25 02:47:27:610PM Plasma Ok

26 03:00:23:800PM Plasma Ok

27 03:12:03:690PM Plasma Ok

28 03:25:45:430PM Plasma Ok

29 03:39:04:590PM Plasma Ok

30 03:53:48:910PM Plasma Ok

31 04:03:14:040PM Plasma Ok

32 04:16:31:410PM Plasma Ok

33 04:27:05:420PM Plasma Ok

34 04:42:21:240PM Plasma Ok

35 04:55:37:280PM Plasma Ok

36 05:02:32:260PM Plasma Ok

Session Leader Comments
Feb 17 1998 08:07:46:730AM		Steve Wolfe	MP133 Post-Boronization SL: wolfe PO: marmar Boronization was completed on Saturday morning. He ECDC until early this morning, then switch over to D2 for two hours. Plan for first part of 980217: ------------------------- Start with standard Tuesday OH test, except: Enable B-top valve for hybrid puff during test shot. Run fiducials until reasonably reproducible startup and plasma operation is regained. Try adjusting pre-puff to compensate for wall pumping, if significant. If sufficiently frustrated by lack of startup, run some additional D2 ECDC. Once fiducials look ok, run some 1MA discharges like 980210025-26. Then begin MP155: Confinement scaling, with Martin as SL. -
Feb 17 1998 08:58:54:550AM		Steve Wolfe	08:57 Turned on Ratiomatics
Feb 17 1998 12:19:08:060PM		Martin Greenwald	mp 155 hmode confinement scaling Session Leader - Greenwald Phys Op - Marmar We want to look at the scaling with Bt, P, and kappa The run should start with fiducials until we get good h-modes. It's probably easiest to start the confinement scans with the power scaling, at parameters where the RF can get the maximum power and also where there is the most room between the L/H threshold and that max power. I think this argues for running at 1.0 MA and moderately low density, nl_04 ~ 1. The shape can be our normal shape. The next scan would be with kappa, from the lowest value consistent with a divertor configuration and decent RF coupling to the highest value consistent with axisymetric stability. Perhaps kappa = 1.45 -> 1.75 The RF power can be nominal ~ 2.5 MW or slightly less if that helps for the lowest kappa. Ip = 1 MA would probably help to get higher kappas, q95 would be around 3 at the lowest kappas. If time permits we would scan Bt consistent with minority heating at r/a < .5, that is Bt = 4.5 -> 6.1. This would be with our normal shape, Ip = 1MA and Prf ~ 2.5 MW.
Feb 17 1998 10:06:13:280AM	980217001	Steve Wolfe	shot 1: Tueday oh test. Ratiomatic says .045mTorr, a bit on the low side.
Feb 17 1998 10:12:59:210AM	980217002	Steve Wolfe	shot 2: plasma attempt. fizzle. early bd (3msec), br=-.001.
Feb 17 1998 10:23:09:860AM	980217003	Steve Wolfe	shot 3: br tweak. fizzle.
Feb 17 1998 10:33:09:840AM	980217004	Steve Wolfe	shot 4: gas tweak. fizzle.
Feb 17 1998 10:40:06:430AM	980217005	Steve Wolfe	shot 5: br tweak (back to .005) plasma. 2 hmodes. 1 injection. 110kJ.
Feb 17 1998 10:51:35:550AM	980217006	Steve Wolfe	shot 6: Drop the pre-puff, trying to outguess (if not outgas) the plasma. plasma - Two in a row! one long h-mode. 250kW on 2pi, and no step at 2nd RF increment. 115kJ. 1.3e13neut/sec
Feb 17 1998 11:17:12:750AM	980217007	Steve Wolfe	shot 7: plasma. Three in a row. 1h-mode, 115kJ, 1.3e13 n/sec. Looks good. Next shot, 1MA like 980210025.
Feb 17 1998 11:27:12:710AM	980217008	Steve Wolfe	shot 8: plasma. 1 h-mode, EDA, 1 trip. between 2 and 3e13n/sec. ; 160kJ. 2 injections, .91sec and 1.03 sec.
Feb 17 1998 11:33:41:130AM	980217009	Steve Wolfe	shot 9: reduce the Argon. tune the rf. fizzle.
Feb 17 1998 01:18:38:920PM	980217010	Steve Wolfe	shot 10: decrease pre-puff "just slightly". reduce the Argon. tune the rf. plasma. Early injection almost kills it, rf dropout at 1.04 kills the h-mode for a moment. 199.99kJ, 7.e13 n/sec. rf tripped on voltage limit.
Feb 17 1998 12:05:11:240PM	980217011	Steve Wolfe	shot 11: Increase target density to .9e20 (from .7e20). plasma, rf ran through, up to 2.9MW. 7.5e13n/sec, increasing through pulse. 198kJ. Martin says H=2 with 90% absorption.
Feb 17 1998 12:17:04:740PM	980217011	Martin Greenwald	Good Shot EDA H = 2 assuming f_rf = .9 (SW measures .8) Ip = 1.0 MA Bt = 5.4 ne target = 1.6 nemax = 3.7 div press = 30 mT kappa = 1.68 Ptot = 3.5
Feb 17 1998 12:24:10:660PM	980217012	Martin Greenwald	Good Shot H-mode type: Bt = 5.4 Ip = 1.0 kappa = 1.68 Ptot = 3.7 ne target = 1.6 nemax = 3.8 div n0 = 26 div n0 max = 40 prad/ptot = .33 Wmhd = .189 H = 1.9 (w frf assumed = .8)
Feb 17 1998 12:50:25:320PM	980217013	Martin Greenwald	Good Shot H-mode type: Bt = 5.4 Ip = 1 kappa = 1.67 Ptot = 3.7 ne target = 1.6 nemax = 3.9 div n0 = 30 div n0 max = 37 prad/ptot = .26 Wmhd = .215 H = 2.3 (w frf assumed = .8)
Feb 17 1998 12:49:31:820PM	980217014	Martin Greenwald	fizzle
Feb 17 1998 01:01:17:170PM	980217015	Martin Greenwald	Good Shot H-mode type: Bt = 5.4 Ip = 1 kappa = 1.68 Ptot = 4.1 ne target = 1.5 nemax = 3.7 div n0 = 29 div n0 max = prad/ptot = .4 Wmhd = .233 H = 2.5 (w frf assumed = .8)
Feb 17 1998 01:11:18:670PM	980217016	Martin Greenwald	Fizzle
Feb 17 1998 01:24:05:320PM	980217017	Martin Greenwald	Fizzle
Feb 17 1998 01:35:52:850PM	980217018	Martin Greenwald	fizzle
Feb 17 1998 01:43:07:150PM	980217019	Martin Greenwald	Dud
Feb 17 1998 01:59:50:030PM	980217020	Martin Greenwald	OK shot, lots of RF trips H-mode type: EDA Bt = 5.4 Ip = 1 kappa = 1.68 Ptot = 3.7 ne target = 1.5 nemax = 3.7 div n0 = 30 div n0 max = 25 prad/ptot = .3 Wmhd = 0.2 H = 2.2 (w frf assumed = .8)
Feb 17 1998 02:04:59:410PM	980217021	Martin Greenwald	Fizzle
Feb 17 1998 02:21:25:270PM	980217022	Martin Greenwald	Good Shot H-mode type: Bt = 5.4 Ip = 1 kappa = 1.68 Ptot = 3.3 ne target = 1.5 nemax = 3.6 div n0 = 30 div n0 max = 29 prad/ptot = .25 Wmhd = .19 H = 2.1 (w frf assumed = .8)
Feb 17 1998 02:27:54:090PM	980217023	Martin Greenwald	Fizzle
Feb 17 1998 02:48:54:310PM	980217024	Martin Greenwald	Good Shot H-mode type: Bt = 5.4 Ip = 1 kappa = 1.68 Ptot = 2.9 ne target = 1.5 nemax = 3.5 div n0 = 25 div n0 max = 20 prad/ptot = .3 Wmhd = .162 H = 1.8 (w frf assumed = .8)
Feb 17 1998 02:54:54:850PM	980217025	Martin Greenwald	Good Shot H-mode type: EDA, but with mildly accumulating impurities Bt = 5.4 Ip = 1 kappa = 1.68 Ptot = 2.5 ne target = 1.5 nemax = 3.5 div n0 = 34 div n0 max = 27 prad/ptot = .45 Wmhd = .14 H = 1.8 (w frf assumed = .8)
Feb 17 1998 03:13:31:250PM	980217026	Martin Greenwald	Good Shot H-mode type: Bt = 5.4 Ip = 1 kappa = 1.68 Ptot = 2.2 ne target = 1.5 nemax = 3.5 div n0 = 25 div n0 max = 25 prad/ptot = .5 Wmhd = .128 H = 1.7 (w frf assumed = .8)
Feb 17 1998 03:19:50:350PM	980217027	Martin Greenwald	Good Shot H-mode type: EDA with some ELMfree character Bt = 5.4 Ip = 1 kappa = 1.68 Ptot = 2.0 ne target = 1.5 nemax = 3.6 div n0 = 30 div n0 max = 20 prad/ptot = .6 Wmhd = .13 H = 1.7 (w frf assumed = .8)
Feb 17 1998 03:34:16:560PM	980217028	Martin Greenwald	Good Shot H-mode type: EDA Bt = 5.4 Ip = 1 kappa = 1.68 Ptot = 3.4 ne target = 1.5 nemax = 3.6 div n0 = 25 div n0 max = 25 prad/ptot = .35 Wmhd = .2 H = 2.1 (w frf assumed = .8)
Feb 17 1998 03:46:37:810PM	980217029	Martin Greenwald	Good Shot EDA, goes limited at about 1 sec H-mode type: Bt = 5.4 Ip = 1 kappa = 1.63 Ptot = 3.3 ne target = 1.5 nemax = 3.7 div n0 = 28 div n0 max = 15 prad/ptot = .28 Wmhd = .17 H = 1.8 (w frf assumed = .8)
Feb 17 1998 03:56:15:790PM	980217030	Martin Greenwald	Fizzle
Feb 17 1998 04:10:41:660PM	980217031	Martin Greenwald	Good Shot H-mode type: EDA, some sort of problem develops at .9 sec Bt = 5.4 Ip = 1 kappa = 1.6 Ptot = 3.1 ne target = 1.5 nemax = 3.7 div n0 = 20 div n0 max = 15 prad/ptot = .4 Wmhd = .2 H = 2.3 (w frf assumed = .8)
Feb 17 1998 04:18:57:980PM	980217032	Martin Greenwald	fizzle
Feb 17 1998 04:34:02:180PM	980217033	Martin Greenwald	Good Shot H-mode type: EDA Bt = 5.4 Ip = 1 kappa = 1.58 Ptot = 3.2 ne target = 1.5 nemax = 3.5 div n0 = 18 div n0 max = 10 prad/ptot = .3 Wmhd = .19 H = 2.1 (w frf assumed = .8)
Feb 17 1998 04:50:00:660PM	980217034	Martin Greenwald	OK Shot, but disruption at 1.1 sec H-mode type: Bt = 5.4 Ip = 1 kappa = 1.53 Ptot = 3 MW ne target = 1.6 nemax = 3.3 div n0 = 18 div n0 max = 10 prad/ptot = .2 Wmhd = .18 H = 2.1 (w frf assumed = .8)
Feb 17 1998 04:58:43:100PM	980217035	Martin Greenwald	Fizzle
Feb 17 1998 05:04:48:460PM	980217036	Martin Greenwald	Early Disruption

Physics Operator Comments
Feb 17 1998 10:13:39:680AM	980217002	Earl Marmar	Loaded from 980210004 B_R offset to .0045 from .005T prepuff to 17 msec from 14 msec enable argon fizzle; B_R a little negative.
Feb 17 1998 10:22:24:640AM	980217003	Earl Marmar	B_R offset to .0055 from .0045 T fizzle
Feb 17 1998 10:31:22:780AM	980217004	Earl Marmar	prepuff to 15 ms from 17; fizzle; B_R now looks slightly positive
Feb 17 1998 10:43:38:090AM	980217005	Earl Marmar	B_R offset to .005 from .0055; plasma;
Feb 17 1998 10:52:37:140AM	980217006	Earl Marmar	reduce prepuff to 13 ms; plasma;
Feb 17 1998 11:16:10:370AM	980217007	Earl Marmar	no changes; plasma
Feb 17 1998 11:19:55:870AM	980217008	Earl Marmar	go to 1 MA; load segment 3 from 980210025; increase Argon puff to 14 msec from 10; plasma
Feb 17 1998 11:32:00:270AM	980217009	Earl Marmar	reduce Argon to 10 msec; fizzle
Feb 17 1998 11:47:13:020AM	980217010	Earl Marmar	reduce prepuff to 12 msec from 13; plasma
Feb 17 1998 12:01:51:070PM	980217011	Earl Marmar	reduce argon from 10 to 9 msec; raise nl_04 from 7e19 to 9e19; adjust pulse gas preprog voltage; plasma
Feb 17 1998 12:18:55:250PM	980217012	Earl Marmar	RF turn-on earlier; no PCS changes; plasma
Feb 17 1998 12:35:26:530PM	980217013	Earl Marmar	slightly more RF power; plasma
Feb 17 1998 12:48:48:140PM	980217014	Earl Marmar	argon to 11 msec from 9; fizzle; late breakdown
Feb 17 1998 01:13:08:020PM	980217015	Earl Marmar	B_R offset to .0045 from .005 T; plasma
Feb 17 1998 01:13:24:260PM	980217016	Earl Marmar	no changes; dud
Feb 17 1998 01:25:53:510PM	980217017	Earl Marmar	increase prepuff to 14 ms from 12 ms; fizzle; B_R looks a bit negative.
Feb 17 1998 01:35:37:670PM	980217018	Earl Marmar	B_R offset to .005 from .0045 T; fizzle
Feb 17 1998 01:43:37:020PM	980217019	Earl Marmar	prepuff to 12 msec from 14 msec; dud
Feb 17 1998 02:01:18:170PM	980217020	Earl Marmar	prefill to 16 msec from 12 msec; EF4 15 Amp more negative at t=0.; plasma
Feb 17 1998 02:07:05:230PM	980217021	Earl Marmar	no changes; fizzle
Feb 17 1998 02:22:18:550PM	980217022	Earl Marmar	prepuff to 14; plasma
Feb 17 1998 02:29:12:680PM	980217023	Earl Marmar	no changes; fizzle
Feb 17 1998 02:37:15:610PM	980217024	Earl Marmar	prepuff to 13 msec; plasma
Feb 17 1998 06:13:40:720PM	980217025	Earl Marmar	5 Amp more negative on EF4; plasma
Feb 17 1998 03:06:50:150PM	980217026	Earl Marmar	no changes; plasma
Feb 17 1998 03:13:53:660PM	980217027	Earl Marmar	no pcs changes; plasma
Feb 17 1998 03:59:01:670PM	980217029	Earl Marmar	lower ZXU 1 cm lower ZCUR 1 cm plasma; big radiated power increase after 1 second. kappa=1.64
Feb 17 1998 03:56:54:380PM	980217030	Earl Marmar	zxl up 1.5 cm zcur up .5 cm zxu up 1cm fizzle
Feb 17 1998 04:15:15:860PM	980217031	Earl Marmar	no further changes from 29; plasma
Feb 17 1998 04:20:39:030PM	980217032	Earl Marmar	zxl up 1 cm; fizzle
Feb 17 1998 04:39:23:230PM	980217033	Earl Marmar	B_r offset to .0045 from .005 T Prepuff to 12 ms from 13 ms plasma; disrupt in rampdown at .6MA
Feb 17 1998 04:50:58:740PM	980217034	Earl Marmar	ZXL up 1 cm ZCURR down 4 mm plasma disrupt at 1.15 s, near end of flattop EF2_lower went to 0 at about .74 seconds
Feb 17 1998 04:59:37:510PM	980217035	Earl Marmar	reload seg 3 from shot 24 lower nl_04 demand to 7e19 fizzle B_R looks a bit negative
Feb 17 1998 05:09:44:830PM	980217036	Earl Marmar	B_r offset to .005 from .0045 T disrupt at .32 seconds; something fell in?

Engineering Operator Comments
Shot	Time	Type	Status	Comment
1	09:52:56:810AM	Test	Ok	coax test shot ok
2	10:07:45:020AM	Plasma	Ok
3	10:16:25:500AM	Plasma	Ok
4	10:25:00:900AM	Plasma	Ok
5	10:33:46:620AM	Plasma	Ok
6	10:44:57:820AM	Plasma	Ok
7	11:00:06:430AM	Plasma	Ok
8	11:18:10:360AM	Plasma	Ok
9	11:30:21:020AM	Plasma	Ok
10	11:39:38:000AM	Plasma	Ok
11	11:54:48:990AM	Plasma	Ok
12	12:13:09:940PM	Plasma	Ok
13	12:28:16:420PM	Plasma	Ok
14	12:43:38:810PM	Plasma	Ok
15	12:54:11:390PM	Plasma	Ok
16	01:09:31:680PM	Plasma	Ok
17	01:21:10:560PM	Plasma	Ok
18	01:31:47:540PM	Plasma	Ok
19	01:40:52:490PM	Plasma	Ok
20	01:50:26:070PM	Plasma	Ok
21	02:03:08:300PM	Plasma	Ok
22	02:12:27:360PM	Plasma	Ok
23	02:25:27:790PM	Plasma	Ok
24	02:35:20:800PM	Plasma	Ok
25	02:47:27:610PM	Plasma	Ok
26	03:00:23:800PM	Plasma	Ok
27	03:12:03:690PM	Plasma	Ok
28	03:25:45:430PM	Plasma	Ok
29	03:39:04:590PM	Plasma	Ok
30	03:53:48:910PM	Plasma	Ok
31	04:03:14:040PM	Plasma	Ok
32	04:16:31:410PM	Plasma	Ok
33	04:27:05:420PM	Plasma	Ok
34	04:42:21:240PM	Plasma	Ok
35	04:55:37:280PM	Plasma	Ok
36	05:02:32:260PM	Plasma	Ok