Alcator C-Mod Run 940608 Information

Miniproposals

Miniproposal: 059

Date Filed: 6/6/1994

Title: ICRF Heating (PRF>1 MW)

First Author: Yuichi Takase

Session Leader: Yuichi Takase (shots 1-29)

Operators
Session leader(s):	Yuichi Takase
Physics operator(s):	Steve Golovato
Engineering operator(s):	Vinny Bertolino,Frank Silva

Engineering Operator Run Comment
undecided

Session Leader Plans

Physics Operators Plans

Session Leader Summaries

Entered: Jul 7 2004 03:49:10:993PM

Author: To Be Determined

Run Summary for 940601

SL: Takase
PO: Golovato
EO: Silva/Bertolino

MP059 RF Heating (> 1 MW)

The objective of this proposal is to perform
parameter scans at a power level of over 1 MW.
Todays objective was to perform the following
scans in inner-wall limited plasmas, starting
from a reload of 940602019:
1. Density scan
2. Current scan
3. Toroidal field scan

We have completed the lower density half of
density scan, but had difficulty completing
the high density half. The reason for this
difficulty is the unexpected difficulty trying
to tune to high density plasmas. There were
additional problems with the hybrid (see physics
operator's summary) and a general difficulty to
get stable high density plasmas.

Initial analysis of today's results indicate
that the heating (stored energy increase) was
nearly independent of density. Another indication
is that the heating may be better at higher current
(although we did not intentionally run different
currents, we got them due to the hybrid problem).
These results are consistent with L-mode scaling.

On shot 005, we observed an ELM-free H-mode
which turned into an ELMy H-mode and back to
L-mode. The RF power did not trip, but because
of large loading change, the RF power dropped
by a half during H-mode.

Physics Operator Summaries

Entered: Jul 7 2004 04:36:51:693PM

Author: To Be Determined

Physics Operator Summary - Run 940608

SL - Takase
PO - Golovato
EO - Silva/Bertolino

The main goals of the run were to do density and current scans at
high rf power with inner wall limited plasmas. We started with shot
940602019, our best shot from last week. We got plasmas from the
first shot and every shot except shot 12, which was an inexplicable
fizzle. We accomplished a density scan in the downward direction over
shots 3-13, but had trouble matching to the plasma at higher than
nl_04 ~ 8.e19 cm-2. Shots 14-16 had nl_04 ~> 9.e19 cm-2 but no high
power rf. All shots up to this point were at 800 ka.

From shot 17 onward, we had a problem with the hybrid. The current dropped
in two steps, 710 ka on shot 17 and about 650 from then on. The hybrid
in fact thought the currennt was still 800 ka held it constant at what
turned out to be the incorrect value. The Rogowskis and reconstructions
all agreed that the current was in fact the lower value. The problem
was thought to be a spontaneous change in gain of one of the imfamous
Livermore isoamps on the hybrid inputs, which required cell access to remedy
and was left for after the run. The problem turned out to be a bad cable
carrying the current signal to all current referenced hybrid wires, which
therefore all had a value of zero, that is, there was no feedback control
on these wires. The LEMO connector had unscrewed and no longer made
contact, an advertisement for crimped connectors. This would have been
picked up in the plasma control if we hadn't been running such vanilla
plasmas, symmetric up-down and positioned at the nominal R-Z center.
The current dropped because the now unloaded isoamp had an effectively
higher gain, so the current appeared to the hybrid to be higher than it
actually was. This is another "feature" of the Livermore isoamps.
The problem should be fixed for tomorrow but we should all be more
sympathetic to Horne's desire to get rid of these isoamps.

Running at lower current for the rest of the run, we had trouble both in
running at higher density and in tuning to the higher density. We appeared
to have a density limit at 650 ka at nl_04 ~ 1.e20 cm-2, where we
observed a locked mode which led sooner or later, depending on the shot, to a
disruption (see shots 20 and 21 for example). We also had disruptions at the
lowest densities we ran, nl_04 <~ 4.e19 cm-2. These were at 800 ka and quite
potent, so beware when running at low density, particularly during the
rampdown, where added gas can help avoid a late disruption (see shots 7-9).
Conversely, at high density and lower current, too much gas in the rampdown
often led to the locked mode and disruption (see shots 27 and 28).

Shot-by-shot comments are in the logbook under the physics_operator topic.
The shot accounting was 27 plasmas and one fizzle.

Session Leader Comments

Jun 8 1994 08:47:24:080AM Yuichi Takase MP059 RF Heating

Parameter scans (inner-wall limited plasma):
1. Density scan
2. Current scan
3. Toroidal field scan (possibly)

Start from 940602019

Jun 8 1994 09:19:41:860AM 940608001 Yuichi Takase Early disruption, dirty shot.

Jun 8 1994 09:45:22:330AM 940608002 Yuichi Takase Good shot.
Ip=0.8, nel_04=8-9, Prf=1.4

Jun 8 1994 09:47:44:130AM 940608003 Yuichi Takase Good shot, almost the same as 002.
Ip=0.8, nel_04=8-9, Prf=1.4

Jun 8 1994 10:06:09:340AM 940608004 Yuichi Takase Good shot, RF pulse 0.65-0.75sec.
Ip=0.8, nel_04=8-9, Prf=1.6-1.3.

Jun 8 1994 10:33:11:200AM 940608005 Yuichi Takase Good shot, RF pulse 0.65-0.75sec.
H-mode (ELM-free to ELMy), RF survived, but power halved.
Ip=0.8, nel_04=7-10, Prf=1.5-0.85.

Jun 8 1994 10:53:46:190AM 940608006 Yuichi Takase RF interrupts.
Tuning looks OK, probably voltage limit because of low loading (40kV).
Ip=0.8, nel_04=6.5, Prf=1.7 (interrupts).

Jun 8 1994 11:06:58:870AM 940608007 Yuichi Takase RF interrupts.
Ip=0.8, nel_04=5.5, Prf=1.3-1.1 (interrupts).

Jun 8 1994 11:29:49:170AM 940608008 Yuichi Takase RF interrupts.
Ip=0.8, nel_04=4.5, Prf=1.0-1.2 (interrupts).

Jun 8 1994 11:36:40:500AM 940608009 Yuichi Takase Disrupted at 0.6sec, no high power RF.

Jun 8 1994 12:03:20:450PM 940608010 Yuichi Takase Disrupted during Ip rampdown.
Ip=0.8, nel_04=2.8, Prf=1.3 (interrupts).

Jun 8 1994 12:14:26:550PM 940608011 Yuichi Takase Good shot again.
Ip=0.8, nel_04=6.0, Prf=1.4 (1 interrupt at the end).

Jun 8 1994 12:19:39:500PM 940608012 Yuichi Takase Fizzle.

Jun 8 1994 01:03:02:010PM 940608013 Yuichi Takase Ip=0.8, nel_04=7.4-8.3, Prf=1.5.

Jun 8 1994 01:04:00:260PM 940608014 Yuichi Takase No high power RF (loading too high).
Ip=0.8, nel_04=9.2, Prf=0.

Jun 8 1994 01:35:11:530PM 940608015 Yuichi Takase No high power RF (loading too high).
Ip=0.8, nel_04=8.9, Prf=0.

Jun 8 1994 01:35:32:600PM 940608016 Yuichi Takase No high power RF (loading too high).
Still trying to tune.
Ip=0.8, nel_04=9.4, Prf=0.

Jun 8 1994 01:54:20:300PM 940608017 Yuichi Takase No high power RF (loading too high).
Still trying to tune.
Ip=0.7, nel_04=10., Prf=0.

Jun 8 1994 02:13:03:870PM 940608018 Yuichi Takase No high power RF (loading too high).
Still trying to tune.
Ip=0.65, nel_04=9.3, Prf=0.

Jun 8 1994 03:15:19:460PM 940608020 Yuichi Takase No high power RF.
Having HYBRID problems since shot 017,

Jun 8 1994 03:15:52:750PM 940608021 Yuichi Takase A little better tuning, 100kW for a short time.

Jun 8 1994 03:20:40:700PM 940608022 Yuichi Takase Bad tune again.
Density lower nel_04=7 (reloaded shot 003).

Jun 8 1994 03:43:01:160PM 940608023 Yuichi Takase Good RF pulse (back to original plasma and original tune).
Ip=0.68, nel_04=6.7-7.0, Prf=0.9-1.2.

Jun 8 1994 03:54:00:280PM 940608024 Yuichi Takase Ip=0.68, nel_04=7.8, Prf=1.5.

Jun 8 1994 04:22:02:690PM 940608025 Yuichi Takase Disrupted, no RF.

Jun 8 1994 04:22:42:130PM 940608026 Yuichi Takase Disrupted, RF interrupts (15 Ohm loading).

Jun 8 1994 04:55:49:530PM 940608027 Yuichi Takase Disruptive plasma, no high power RF.

Jun 8 1994 04:56:05:710PM 940608028 Yuichi Takase Disruptive plasma, no high power RF.

Jun 8 1994 05:08:36:320PM 940608028 Yuichi Takase Plasma was OK, but lowish density (nel_04=6), no high power RF.

Physics Operator Comments

Jun 8 1994 09:04:24:560AM Steve Golovato Run 940608 - ICRF in 1-2 MW Range

SL - Takase
PO - Golovato
EO - Silva

ECDC in D 6-8am

Run Goals - density , current scans at high rf power
if time, H concentration scan and/or
diverted discharge development

Starting with shot 940602019, which was best previous shot,
had 2 cm outer gap, limited on inner wall.
Note that the current flattop ends at 800 ms on these shots
Power supply incersion time at 800ms..
Running this way should allow more shots per day.

Jun 8 1994 10:53:36:310AM Steve Golovato gas pre-fill set to 1.2e-5 from first shot.

Jun 8 1994 09:17:28:770AM 940608001 Steve Golovato 9406080010 - 9:10am
Copied shot 940602019.
Plasma, but disruptive, ended at 500ms, 600ka.

Jun 8 1994 09:35:49:060AM 940608002 Steve Golovato 940608002 - try again, no changes.
Plasma. Good shot. 800ms,1.03s.

Jun 8 1994 09:45:13:750AM 940608003 Steve Golovato 940608003 - again, no changes.1.01s.

Jun 8 1994 10:05:28:960AM 940608004 Steve Golovato 940608004- start density scan, starting at lower density.
Good shot, lower nl. 7.5e19, was 8.4e19.

Jun 8 1994 10:24:40:860AM 940608005 Steve Golovato 940608005- gas set to 30V, from 34V.
nl04=7.e19

Jun 8 1994 10:37:10:820AM 940608006 Steve Golovato 940608006 - gas set to 26V.
nl04=6.4e19

Jun 8 1994 11:01:34:350AM 940608007 Steve Golovato 940608007 - nl04=5.4e19
had eliminated gas puff at 850ms for tom luke for this shot
got disruption during current rampdown. will add it back for next shot..

Jun 8 1994 11:06:34:320AM 940608007 Steve Golovato 940608007 - gas puff set to 20V.

Jun 8 1994 11:25:46:140AM 940608008 Steve Golovato 940608008 - late puff put back at 850ms, 60V (was 80V).
continuous gas at 16V
nl04=4.3e19. moly burst at about 690ms.

Jun 8 1994 11:26:35:350AM 940608008 Steve Golovato 940608008 - late puff allowed soft landing at 1.15s.

Jun 8 1994 11:36:23:120AM 940608009 Steve Golovato 940608009 - retake last shot, hope for no moly event.
disrupted early at 620ms, before rf pulse.
this is as low as we'll go in density.

Jun 8 1994 11:54:43:910AM 940608010 Steve Golovato 940608010 - going back to shot 006, midway back to starting density.
puff set to 26V. late puff set back to 60V.
following previous disruption, got low density, nl04=2.75e19.
disrupted at 865ms.

Jun 8 1994 12:09:24:790PM 940608011 Steve Golovato 940608011 - raised puff voltage to 34V, increased late puff to 70V,
started it a little earlier.
no disruption. things were getting at little scary, with large
halo currents reported on the last two shots.
nl04=5.6e19.

Jun 8 1994 12:28:13:080PM 940608012 Steve Golovato 940608012 - raised puff to 40V.
fizzle. not clear why, breakdown looked like previous shot.

Jun 8 1994 12:39:58:440PM 940608013 Steve Golovato 940608013 - try again.
worked. but almost didn't, current dropped between 18 and 20 ms,
then continued rising. i'm told by horne and granetz in EXACTLY
the same words that this is an exteme example of the "hutchinson
hesitation".
nl04= 7.4e19.

Jun 8 1994 12:54:45:530PM 940608014 Steve Golovato 940608014 - puff at 50V.
worked again, n hesitation.
nl04=9.25e19, but no high power rf.

Jun 8 1994 01:15:59:440PM 940608015 Steve Golovato 940608015 - rf mis-tuned at this density, no high power pulse.
nl04=8.85e19. (incidentally, these nl's are at 650ms, when
the high power rf turns on).
disrupted a little early, at 965ms.

Jun 8 1994 01:30:00:730PM 940608016 Steve Golovato 940608016 - try to get high power rf again.
no high power pulse. nl04=9.4e19

Jun 8 1994 01:45:57:600PM 940608017 Steve Golovato 940608017 - removing late puff, getting disruptions during rampdown
at these high gas puff levels.
good plasma, still no rf. nl04=1.e20

Jun 8 1994 01:50:49:400PM 940608017 Steve Golovato 940608017 - current didn't reach 800ka, only got 710ka.

Jun 8 1994 02:18:57:980PM 940608018 Steve Golovato 940608018 - density creeping up, a moving target for tuning.
lowering puff to 46V. still no rf. nl04=9.1e19.
curent flattop at 650ka. hybrid thinks the current is correct.
perhaps an offset problem.

Jun 8 1994 02:34:31:520PM 940608019 Steve Golovato 940608019- same thing, 650ka flattop when programmed for 800ka.
no rf. nl04=9.e19. hybrid thinks it is 800ka. must be gain
in isoamp has changed. all other measures, rogowskis and
reconstuctions, say 650ka.

Jun 8 1994 02:51:59:040PM 940608020 Steve Golovato 940608020 - lowered puff to 40V. plasma disruptive starting
at 600ms. not clear why.
still 650ka.

Jun 8 1994 02:56:38:820PM 940608020 Steve Golovato 940608020 - locked mode at 617ms cause of problems (snipes reports).

Jun 8 1994 03:06:34:380PM 940608021 Steve Golovato 940608021- disrupted at 633ms. loacked mode again.

Jun 8 1994 03:16:34:370PM 940608022 Steve Golovato 940608022- reloaded shot 003. running it without any changes.
nl04=7.e19. still 650ka.

Jun 8 1994 03:19:45:960PM 940608022 Steve Golovato 940608022 - looked like shot 003. going back to tuning for shot 003.

Jun 8 1994 03:28:39:010PM 940608023 Steve Golovato 940608023 - good shot, good rf. still 650ka.now start
increasing density more slowly so we can track tuning.

Jun 8 1994 03:43:10:340PM 940608024 Steve Golovato 940608024 - gas to 42V from 39V.
current moving around a little, was 680ka last two shots.
nl04=7.6e19. rf ran.

Jun 8 1994 04:02:06:410PM 940608025 Steve Golovato 940608025 - gas to 44V.
640ka, disrupted at 615ms, probably locked mode again.

Jun 8 1994 04:02:40:200PM 940608025 Steve Golovato 940608025 - gas to 44V.
640ka, disrupted at 615ms, probably locked mode again.
density ramped to 1.e20 at disruption.

Jun 8 1994 04:16:39:340PM 940608026 Steve Golovato 940608026 - gas programming changed so still peaks at 44V
but rises to this value more slowly, i.e., less total gas.
get locked mode when nl04 hits about 1.e20, this time at 670ms.
640ka this shot.

Jun 8 1994 04:34:54:870PM 940608027 Steve Golovato 940608027 - lowered gas to 40V max again, see what happens.
lost at 880ms. 660ka. nl04=7.8e19.

Jun 8 1994 04:44:00:220PM 940608028 Steve Golovato 940608028 - got rid of late puff, may have caused late disruption
last shot. tweeked gas up a little to 41V peak.
late puff prevents disruptions at low density, causes them at
high density.
shaking plasma (as seen on video monitor), typically happens
with locked mode, this time at about 700ms.
plasma ran to 960ms, 640ka. nl04=9.e19.

oh1 failed in inversion.

Jun 8 1994 04:57:37:950PM 940608029 Steve Golovato 940608029 - good shot but no high power rf. 680ka. nl04=6.5e19
after several disruptive shots, get much less density without
changing gas, as happened this shot.

Engineering Operator Comments

Shot Time Type Status Comment

1 09:07:58:820AM Plasma Ok plasma disrupt

2 09:20:15:950AM Plasma Ok plasma

3 09:37:47:830AM Plasma Ok Plasma

4 09:52:53:610AM Plasma Ok plasma

5 10:15:32:400AM Plasma Ok plasma

6 10:32:49:520AM Plasma Ok plasma

7 10:52:55:390AM Plasma Ok small disruption

8 11:11:39:460AM Plasma Ok plasma

9 11:28:37:690AM Plasma Ok plasma disruption

10 11:46:18:410AM Plasma Ok plasma disruption

11 12:00:17:480PM Plasma Ok plasma disruption

12 12:12:48:430PM Plasma Ok no breakdown

13 12:29:28:740PM Plasma Ok no faults

14 12:49:25:420PM Plasma Ok plasma, comm fault oh1 after shot

15 01:01:13:850PM Plasma Ok comm fails in inversion

16 01:19:37:060PM Plasma Ok no faults

17 01:40:10:980PM Plasma Ok oh1 comm fault in inversion

18 02:00:23:710PM Plasma Ok no faults

19 02:15:36:600PM Plasma Ok no faults

20 02:36:14:990PM Plasma Ok no faults

21 02:51:49:780PM Plasma Ok no faults

22 03:08:48:610PM Plasma Ok no faults

23 03:23:16:740PM Plasma Ok no faults

24 03:37:59:080PM Plasma Ok no faults

25 03:56:01:730PM Plasma Ok no faults

26 04:10:09:490PM Plasma Ok no faults

27 04:26:11:950PM Plasma Ok no faults

28 04:38:01:210PM Plasma Ok oh1 comm fault in inversion

29 04:52:51:250PM Plasma Ok no faults

Session Leader Comments
Jun 8 1994 08:47:24:080AM		Yuichi Takase	MP059 RF Heating Parameter scans (inner-wall limited plasma): 1. Density scan 2. Current scan 3. Toroidal field scan (possibly) Start from 940602019
Jun 8 1994 09:19:41:860AM	940608001	Yuichi Takase	Early disruption, dirty shot.
Jun 8 1994 09:45:22:330AM	940608002	Yuichi Takase	Good shot. Ip=0.8, nel_04=8-9, Prf=1.4
Jun 8 1994 09:47:44:130AM	940608003	Yuichi Takase	Good shot, almost the same as 002. Ip=0.8, nel_04=8-9, Prf=1.4
Jun 8 1994 10:06:09:340AM	940608004	Yuichi Takase	Good shot, RF pulse 0.65-0.75sec. Ip=0.8, nel_04=8-9, Prf=1.6-1.3.
Jun 8 1994 10:33:11:200AM	940608005	Yuichi Takase	Good shot, RF pulse 0.65-0.75sec. H-mode (ELM-free to ELMy), RF survived, but power halved. Ip=0.8, nel_04=7-10, Prf=1.5-0.85.
Jun 8 1994 10:53:46:190AM	940608006	Yuichi Takase	RF interrupts. Tuning looks OK, probably voltage limit because of low loading (40kV). Ip=0.8, nel_04=6.5, Prf=1.7 (interrupts).
Jun 8 1994 11:06:58:870AM	940608007	Yuichi Takase	RF interrupts. Ip=0.8, nel_04=5.5, Prf=1.3-1.1 (interrupts).
Jun 8 1994 11:29:49:170AM	940608008	Yuichi Takase	RF interrupts. Ip=0.8, nel_04=4.5, Prf=1.0-1.2 (interrupts).
Jun 8 1994 11:36:40:500AM	940608009	Yuichi Takase	Disrupted at 0.6sec, no high power RF.
Jun 8 1994 12:03:20:450PM	940608010	Yuichi Takase	Disrupted during Ip rampdown. Ip=0.8, nel_04=2.8, Prf=1.3 (interrupts).
Jun 8 1994 12:14:26:550PM	940608011	Yuichi Takase	Good shot again. Ip=0.8, nel_04=6.0, Prf=1.4 (1 interrupt at the end).
Jun 8 1994 12:19:39:500PM	940608012	Yuichi Takase	Fizzle.
Jun 8 1994 01:03:02:010PM	940608013	Yuichi Takase	Ip=0.8, nel_04=7.4-8.3, Prf=1.5.
Jun 8 1994 01:04:00:260PM	940608014	Yuichi Takase	No high power RF (loading too high). Ip=0.8, nel_04=9.2, Prf=0.
Jun 8 1994 01:35:11:530PM	940608015	Yuichi Takase	No high power RF (loading too high). Ip=0.8, nel_04=8.9, Prf=0.
Jun 8 1994 01:35:32:600PM	940608016	Yuichi Takase	No high power RF (loading too high). Still trying to tune. Ip=0.8, nel_04=9.4, Prf=0.
Jun 8 1994 01:54:20:300PM	940608017	Yuichi Takase	No high power RF (loading too high). Still trying to tune. Ip=0.7, nel_04=10., Prf=0.
Jun 8 1994 02:13:03:870PM	940608018	Yuichi Takase	No high power RF (loading too high). Still trying to tune. Ip=0.65, nel_04=9.3, Prf=0.
Jun 8 1994 03:15:19:460PM	940608020	Yuichi Takase	No high power RF. Having HYBRID problems since shot 017,
Jun 8 1994 03:15:52:750PM	940608021	Yuichi Takase	A little better tuning, 100kW for a short time.
Jun 8 1994 03:20:40:700PM	940608022	Yuichi Takase	Bad tune again. Density lower nel_04=7 (reloaded shot 003).
Jun 8 1994 03:43:01:160PM	940608023	Yuichi Takase	Good RF pulse (back to original plasma and original tune). Ip=0.68, nel_04=6.7-7.0, Prf=0.9-1.2.
Jun 8 1994 03:54:00:280PM	940608024	Yuichi Takase	Ip=0.68, nel_04=7.8, Prf=1.5.
Jun 8 1994 04:22:02:690PM	940608025	Yuichi Takase	Disrupted, no RF.
Jun 8 1994 04:22:42:130PM	940608026	Yuichi Takase	Disrupted, RF interrupts (15 Ohm loading).
Jun 8 1994 04:55:49:530PM	940608027	Yuichi Takase	Disruptive plasma, no high power RF.
Jun 8 1994 04:56:05:710PM	940608028	Yuichi Takase	Disruptive plasma, no high power RF.
Jun 8 1994 05:08:36:320PM	940608028	Yuichi Takase	Plasma was OK, but lowish density (nel_04=6), no high power RF.

Physics Operator Comments
Jun 8 1994 09:04:24:560AM		Steve Golovato	Run 940608 - ICRF in 1-2 MW Range SL - Takase PO - Golovato EO - Silva ECDC in D 6-8am Run Goals - density , current scans at high rf power if time, H concentration scan and/or diverted discharge development Starting with shot 940602019, which was best previous shot, had 2 cm outer gap, limited on inner wall. Note that the current flattop ends at 800 ms on these shots Power supply incersion time at 800ms.. Running this way should allow more shots per day.
Jun 8 1994 10:53:36:310AM		Steve Golovato	gas pre-fill set to 1.2e-5 from first shot.
Jun 8 1994 09:17:28:770AM	940608001	Steve Golovato	9406080010 - 9:10am Copied shot 940602019. Plasma, but disruptive, ended at 500ms, 600ka.
Jun 8 1994 09:35:49:060AM	940608002	Steve Golovato	940608002 - try again, no changes. Plasma. Good shot. 800ms,1.03s.
Jun 8 1994 09:45:13:750AM	940608003	Steve Golovato	940608003 - again, no changes.1.01s.
Jun 8 1994 10:05:28:960AM	940608004	Steve Golovato	940608004- start density scan, starting at lower density. Good shot, lower nl. 7.5e19, was 8.4e19.
Jun 8 1994 10:24:40:860AM	940608005	Steve Golovato	940608005- gas set to 30V, from 34V. nl04=7.e19
Jun 8 1994 10:37:10:820AM	940608006	Steve Golovato	940608006 - gas set to 26V. nl04=6.4e19
Jun 8 1994 11:01:34:350AM	940608007	Steve Golovato	940608007 - nl04=5.4e19 had eliminated gas puff at 850ms for tom luke for this shot got disruption during current rampdown. will add it back for next shot..
Jun 8 1994 11:06:34:320AM	940608007	Steve Golovato	940608007 - gas puff set to 20V.
Jun 8 1994 11:25:46:140AM	940608008	Steve Golovato	940608008 - late puff put back at 850ms, 60V (was 80V). continuous gas at 16V nl04=4.3e19. moly burst at about 690ms.
Jun 8 1994 11:26:35:350AM	940608008	Steve Golovato	940608008 - late puff allowed soft landing at 1.15s.
Jun 8 1994 11:36:23:120AM	940608009	Steve Golovato	940608009 - retake last shot, hope for no moly event. disrupted early at 620ms, before rf pulse. this is as low as we'll go in density.
Jun 8 1994 11:54:43:910AM	940608010	Steve Golovato	940608010 - going back to shot 006, midway back to starting density. puff set to 26V. late puff set back to 60V. following previous disruption, got low density, nl04=2.75e19. disrupted at 865ms.
Jun 8 1994 12:09:24:790PM	940608011	Steve Golovato	940608011 - raised puff voltage to 34V, increased late puff to 70V, started it a little earlier. no disruption. things were getting at little scary, with large halo currents reported on the last two shots. nl04=5.6e19.
Jun 8 1994 12:28:13:080PM	940608012	Steve Golovato	940608012 - raised puff to 40V. fizzle. not clear why, breakdown looked like previous shot.
Jun 8 1994 12:39:58:440PM	940608013	Steve Golovato	940608013 - try again. worked. but almost didn't, current dropped between 18 and 20 ms, then continued rising. i'm told by horne and granetz in EXACTLY the same words that this is an exteme example of the "hutchinson hesitation". nl04= 7.4e19.
Jun 8 1994 12:54:45:530PM	940608014	Steve Golovato	940608014 - puff at 50V. worked again, n hesitation. nl04=9.25e19, but no high power rf.
Jun 8 1994 01:15:59:440PM	940608015	Steve Golovato	940608015 - rf mis-tuned at this density, no high power pulse. nl04=8.85e19. (incidentally, these nl's are at 650ms, when the high power rf turns on). disrupted a little early, at 965ms.
Jun 8 1994 01:30:00:730PM	940608016	Steve Golovato	940608016 - try to get high power rf again. no high power pulse. nl04=9.4e19
Jun 8 1994 01:45:57:600PM	940608017	Steve Golovato	940608017 - removing late puff, getting disruptions during rampdown at these high gas puff levels. good plasma, still no rf. nl04=1.e20
Jun 8 1994 01:50:49:400PM	940608017	Steve Golovato	940608017 - current didn't reach 800ka, only got 710ka.
Jun 8 1994 02:18:57:980PM	940608018	Steve Golovato	940608018 - density creeping up, a moving target for tuning. lowering puff to 46V. still no rf. nl04=9.1e19. curent flattop at 650ka. hybrid thinks the current is correct. perhaps an offset problem.
Jun 8 1994 02:34:31:520PM	940608019	Steve Golovato	940608019- same thing, 650ka flattop when programmed for 800ka. no rf. nl04=9.e19. hybrid thinks it is 800ka. must be gain in isoamp has changed. all other measures, rogowskis and reconstuctions, say 650ka.
Jun 8 1994 02:51:59:040PM	940608020	Steve Golovato	940608020 - lowered puff to 40V. plasma disruptive starting at 600ms. not clear why. still 650ka.
Jun 8 1994 02:56:38:820PM	940608020	Steve Golovato	940608020 - locked mode at 617ms cause of problems (snipes reports).
Jun 8 1994 03:06:34:380PM	940608021	Steve Golovato	940608021- disrupted at 633ms. loacked mode again.
Jun 8 1994 03:16:34:370PM	940608022	Steve Golovato	940608022- reloaded shot 003. running it without any changes. nl04=7.e19. still 650ka.
Jun 8 1994 03:19:45:960PM	940608022	Steve Golovato	940608022 - looked like shot 003. going back to tuning for shot 003.
Jun 8 1994 03:28:39:010PM	940608023	Steve Golovato	940608023 - good shot, good rf. still 650ka.now start increasing density more slowly so we can track tuning.
Jun 8 1994 03:43:10:340PM	940608024	Steve Golovato	940608024 - gas to 42V from 39V. current moving around a little, was 680ka last two shots. nl04=7.6e19. rf ran.
Jun 8 1994 04:02:06:410PM	940608025	Steve Golovato	940608025 - gas to 44V. 640ka, disrupted at 615ms, probably locked mode again.
Jun 8 1994 04:02:40:200PM	940608025	Steve Golovato	940608025 - gas to 44V. 640ka, disrupted at 615ms, probably locked mode again. density ramped to 1.e20 at disruption.
Jun 8 1994 04:16:39:340PM	940608026	Steve Golovato	940608026 - gas programming changed so still peaks at 44V but rises to this value more slowly, i.e., less total gas. get locked mode when nl04 hits about 1.e20, this time at 670ms. 640ka this shot.
Jun 8 1994 04:34:54:870PM	940608027	Steve Golovato	940608027 - lowered gas to 40V max again, see what happens. lost at 880ms. 660ka. nl04=7.8e19.
Jun 8 1994 04:44:00:220PM	940608028	Steve Golovato	940608028 - got rid of late puff, may have caused late disruption last shot. tweeked gas up a little to 41V peak. late puff prevents disruptions at low density, causes them at high density. shaking plasma (as seen on video monitor), typically happens with locked mode, this time at about 700ms. plasma ran to 960ms, 640ka. nl04=9.e19. oh1 failed in inversion.
Jun 8 1994 04:57:37:950PM	940608029	Steve Golovato	940608029 - good shot but no high power rf. 680ka. nl04=6.5e19 after several disruptive shots, get much less density without changing gas, as happened this shot.

Engineering Operator Comments
Shot	Time	Type	Status	Comment
1	09:07:58:820AM	Plasma	Ok	plasma disrupt
2	09:20:15:950AM	Plasma	Ok	plasma
3	09:37:47:830AM	Plasma	Ok	Plasma
4	09:52:53:610AM	Plasma	Ok	plasma
5	10:15:32:400AM	Plasma	Ok	plasma
6	10:32:49:520AM	Plasma	Ok	plasma
7	10:52:55:390AM	Plasma	Ok	small disruption
8	11:11:39:460AM	Plasma	Ok	plasma
9	11:28:37:690AM	Plasma	Ok	plasma disruption
10	11:46:18:410AM	Plasma	Ok	plasma disruption
11	12:00:17:480PM	Plasma	Ok	plasma disruption
12	12:12:48:430PM	Plasma	Ok	no breakdown
13	12:29:28:740PM	Plasma	Ok	no faults
14	12:49:25:420PM	Plasma	Ok	plasma, comm fault oh1 after shot
15	01:01:13:850PM	Plasma	Ok	comm fails in inversion
16	01:19:37:060PM	Plasma	Ok	no faults
17	01:40:10:980PM	Plasma	Ok	oh1 comm fault in inversion
18	02:00:23:710PM	Plasma	Ok	no faults
19	02:15:36:600PM	Plasma	Ok	no faults
20	02:36:14:990PM	Plasma	Ok	no faults
21	02:51:49:780PM	Plasma	Ok	no faults
22	03:08:48:610PM	Plasma	Ok	no faults
23	03:23:16:740PM	Plasma	Ok	no faults
24	03:37:59:080PM	Plasma	Ok	no faults
25	03:56:01:730PM	Plasma	Ok	no faults
26	04:10:09:490PM	Plasma	Ok	no faults
27	04:26:11:950PM	Plasma	Ok	no faults
28	04:38:01:210PM	Plasma	Ok	oh1 comm fault in inversion
29	04:52:51:250PM	Plasma	Ok	no faults