Alcator C-Mod Run 1031125 Information

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Miniproposals
Miniproposal:363
Date Filed:11/13/2003
Title:Investigation of the L-H threshold conditions in Lower null, Double null, Upper Null and Limiter Con
First Author:Amanda Hubbard
Session Leader:Amanda Hubbard (shots 1-33)

Operators
Session leader(s):Amanda Hubbard
Physics operator(s):Bill Rowan
Engineering operator(s):Ed Fitzgerald,Bill Parkin

Engineering Operator Run Comment
MP #363 LH Threshold PO:Rowan SL:Hubbard EO:Fitzgerald,Dekow,Parkin

Session Leader Plans

Physics Operators Plans

Session Leader Summaries
Entered: Jul 7 2004 03:49:34:943PM
Author: Amanda Hubbard


Session leader's Run Summary 1031125

Session Leader: Amanda Hubbard
Phys. Op: Bill Rowan
RF Ops: Yijun Lin
Eng. Ops: Bill Parkin/Ed Fitzgerald

MP 363: Investigation of L-H Threshold conditions in LSN, DN, USN and
limiter confugurations.

This run continued, and nearly completed, the run plan for this MP,
following up on the afternoon of 1031124.

Started at Step 2: Lower Single Null. (Shots 3-8)

Did some shape tweaking, and adjusted RF power to determine L-H
threshold. Shots 5-8 have periods in L-mode close to threshold, with
Shots 5,6 the best; ie long steady L-mode pre-transition. Pthresh 850
kW. Unfortunately did not have GPC
in this shape, but do have ETS, probe, flows and rotation. The
'usual' LSN flow direction. Later period of shots had Prf up to 5.6 MW.
Fairly steady EDAish H-modes, but modest confinement.
Shot 1031125008 had best probe data.

Step 3: Double Null (shots 9-19)

Inadvertently started with an Ssep scan (shot 9).

Shots 10-14 each had a period with flat RF at 850 kW, for comparison with
LSN threshold conditions, followed by a power ramp to get an idea of
the threshold. Took some tweaking to get Ssep ~ 0 for the whole flat
top; as a result we got discharges with slightly varying Ssep. John
reports the ohmic rotation has an extremely sensitive, non-linear, variation
with Ssep. Shot 1031125014 was the most nearly DN (Ssep -0.02 to 0.1
cm). The threshold with ramping power was ~ 2 MW.

In subsequent shots with constant RF power, however, we found the L-H
transition occurred at lower power, down to 1.6 MW on shot 18. (Best
DN L-H shot). Density was well controlled, with little fuelling
evident during RF. Interestingly, there is often a gradual increase
in edge Te in the period before the eventual H-mode transition,
suggesting gradual improvement in confinement. This might explain the
lower threshold compared to the ramp. Te9 (at
r/a~0.94) was typically 170 eV at the start of the dithering period,
230 eV at the hard L/H transition. (as compared to typical 130 eV in
LSN). Should have good ETS profiles to get better comparison. For
shot 19, to check Ssep sensitivity and confirm we were really DN,
raised Ssep by 2 mm. Did not get L-H until power ramp, with Prf=3
MW. Threshold is obviously a very sensitive function of Ssep, perhaps
related to strong change in rotation/flows. It would be interesting
to explore this dependence further.

Step 4: Upper SN (shots 20-30)

Used UN shape developed on 1031124, with only slight inner gap tweaks
for probe. As in Step 3, Started with low power period (0.8 MW),
followed by power ramps. Shots 20-22 were good shots. Pthresh in
ramp was 3.7-4 MW. Huge sawteeth in the L-mode, high power phase (eg
shot 21, 5 keV, tst 44 ms).

Once again, the threshold was lower with flat RF power, with an even
more marked evolution of edge Te during nominally steady L-mode. This
may be related to the large sawteeth, and/or to gradual edge confinement
improvement. Te9 was ~170 eV at start of non-linear phase, 300 eV at
L-H transition. Density again very well controlled, even dropping
during RF L-modes. We appear to have outgassed the relevant sources.
H-modes were obtained with 2.9 MW RF, which appears to be the
threshold. (shots 25, 27 stayed in L-mode up to probe-induced
disruption at 0.85 secs. Shot 30, at the same power, had alternating
L and H-mode periods.

Step 5: Limiter (Shot 33; incomplete)
Lost a few shots due to the post-disruption fizzles and eng/ computer
difficulties late in the day, leaving only time for one shot in inner
wall limited configuration. Shot 33 was a good target, but we had
less RF power due to the matching change. L-mode, 2.5 MW. More shots
at higher power will be needed to determine the L-H threshold, or lack
of it. Shot 1031125033 would be a good starting point, might want to
increase elongation.

All in all, a very good run day; thanks to operators, RF, and
attentive diagnosticians. We accomplished most of the run plan and
apparently got good flow, rotation and edge profile data, most of it
still to be analysed. Obviously, power thresholds do depend
sensitively on configuration; we hope to be able to figure out the reason.

Some good shots for further analysis:

L-mode, 850 kW:

LSN: 1031125008
DN: 1031125012 (+0.08),
1031125014 (-0.08 cm) other shots at small Ssep.
USN: 1031125020,21,22

L-mode, at L-H threshold:
LSN: 1031125008 (0.85 kW)
DSN: 1031125018 (1.6 MW)
USN: 1031125030, also 25, 27 (2.9 MW)

Most discharges are also good for ohmic conditions (pre 0.7 s) and
have High Power (5 MW) RF periods for H-mode analysis. PCI crew
reports interesting/different QC mode observation in DN and USN.


Physics Operator Summaries
Entered: Jul 7 2004 04:37:19:833PM
Author: Bill Rowan
Physop Summary for 1031125

MP #363 LH Threshold
Session Leader: Hubbard

Physics operator: Rowan
Engineer Operator: Fitzgerald, Parkin

-----------------------------------------------------------------------------
Summary----------------------------------------------------------------------
Four configurations were successfully used today, Single null upper (SNU),
single null lower (SNL), double null (DN), and inner wall limited. The first
three were taken from a four segment setup that has been used several times in
the last two weeks with success but with some tweaking. The inner limited
discharge is from July 2003 and differed from current discharges in the
A-coil programming,

The SNL discharges were 002 through 008.
The model shot loaded was 1031124033. Segment 2 is the single null lower.
It has a region of high interaction on the lower inner wall. From
its appearance on the video, it is dubbed the "bath tub ring." Disruptions
at the end of 1031124 were attributed to this region. During the first few
shots in this run, the lower x-point was scooted outboard with the avoidance
of disruptions in mind. Since there were no disruptions other than during
rampdown in the first few shots and since the SL specified the lower
triangulariy, the lower x-point was not changed much. Some changes were
requested in inner and outer gaps to facilitate probe measurements. As they
were similar for both gaps only a clearin modification was required. There
were no complaints about RF coupling so the requests for changes amenable
to probe measurements were followed throughout the day.
Note that shot 001 was a dud. The BeamOp had been firing DNB conditioning
shots into the vacuum vessel in order to use the TV camera to observe the
beam flash. Having determined to frost the cryo pumps prior to the main
part of the run, the BeamOp neglected to disable the DNB gate valve and
therefore puffed a significant amount of N2 into the vacuum vessel on the
first shot. This resulted in a dud.

The double null discharges were 009 through 019. The segment number was 4.
The shot loaded had an SSEP scan in segment 4 which the SL
found to be not useful so segment 4 from 1031124015 was loaded for the
remaining double null discharges. The double null configuration formed
in shot 010 at approximately 1s. The SL requested that it be formed
earlier. This required increasing the SSEP gain and then modifiying the
SSEP programming.

The upper single null discharges were 020 through 030.
Shots from 025 through 029 suffered from excessive probe interaction.
There was a UFO emitted from the location of the probe on shot 025.
A disruption soon followed. 026 was a post disruption fizzle. 027
disrupted at the time of the probe plunge. 028 and 029 were post
disruption fizzles.

There was one inner wall discharge: 033. The inner wall programming was
reloaded into segment 3 from 1030701019, segment 2. The nel04 programming
was changed to produce a density comparable to that in previous discharges,
0.8e+19 m-2.
Shots 031 and 032 were also intended as inner wall limited discharges.
031 was a dud due to an engineering problem.
032 was as a no-power shot due to a data system hang.

Score Card
Plasmas 26 002,003,004,005,006,007,008,009,
010,011,012,013,014,016,017,018,
019,020,021,022,023,024,
025(w/probe induced disruption),
027(w/probe induced disruption),
030,033
Fizzles 4 015,026,028,029
(last three probe induced)

Duds 2 001 (DNB related),031(PS problem)
No power shot 1 032 (data system hang)
Total 33


-----------------------------------------------------------------------------

-----------------------------------------------------------------------------
Engineering Setup------------------------------------------------------------

ECDC in D2 at 2e-4 Torr, stopping by 07:00.
Bake at 60 C as well.

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

Power systems the same as on 1031124033

A-coils should be hooked up as on 1031124033 (+Dtop -Dbot -Jtop +Jbot).
Enable the power supply.

Gas setup:
fill B-Top with 6 psi D2 Hybrid enabled (PG4)
fill B-side lower with 1 psi Ar Hybrid enabled (PG1)
leave B-side upper as is Hybrid DISABLED (PG2)
fill C-side with 30 psi D2 Hybrid enabled (PG3)

Enable the following gate valves, assuming no vacuum problems:
ECE, VUV, DNB


RF Setup:Transmitters 1,2,3 & 4 in Run On by 08:00.
-----------------------------------------------------------------------------

-----------------------------------------------------------------------------
Run Plan---------------------------------------------------------------------
MP#363 LH Threshold

Run Plan for MP 363

Optimum shape for USN plasmas was established during run 1031124.

Continue with point 2 from the miniproposal:


2) Switch to LSN. 800 kA, ~ 5.4 T. 3-4 shots.
a) Power ramp up to ~ 3 MW, to determine L-H threshold.
b) Discharge with fixed power just below threshold, for 100-200 ms, followed by
high power phase (4-5 MW). Repeat as needed for probe, HIREX.

3) Switch to DN. 5-6 discharges.
a) 2 Discharges at power which gave L-H threshold in LSN (eg. 1 MW). Document
ETS profiles, flows, rotation.
b) Power ramp to maximum available (5 MW>) to determine the new L-H threshold.
c) As above, make discharges with power just below L-H transition for ~ 200 ms,
followed by higher power to get H-mode phase.

4) Switch to USN. 5-6 discharges
a) 2 Discharges at power which gave L-H threshold in LSN (eg. 1 MW). Document
ETS profiles, flows, rotation.
b) Power ramp to maximum available (5 MW>) to determine the new L-H threshold.
(from prior experience, expect ~ 3.5 MW)
c) As above, make discharges with power just below L-H transition for ~ 200 ms,
followed by higher power to get H-mode phase (eg. 3.5, 5 MW).

5) Switch to Inner wall limited. Repeat sequence. 5-6 discharges.
a) 2 Discharges at power which gave L-H threshold in LSN (eg. 1 MW). Document
ETS profiles, flows, rotation.
b) Power ramp to maximum available (5 MW>) to determine whether an H-mode is
achievable. From prior experiments, expect to need at least 4 MW. If yes,
document profiles at L-H threshold, as above, and in H-mode. If no, document at
highest available RF power to set lower bound on edge Te, rotation etc.
-----------------------------------------------------------------------------


-----------------------------------------------------------------------------
Log-----------------------------------------------------------------------------

Load shot 1031124033.


001. Dud. The DNB gate valve was enabled and the DNB was in a cryo frosting
cycle with N2 at 10e-04 T.
Will take this to be the cause of the dud as this setup produced a 1.4 s on
the last shot yesterday and a fizzle on the next to last shot.

Next shot: Disable the DNB gate valve at the DNB PLC. No PCS changes.


002. Plasma. No disruption at 1.4 as we had yesterday. Evidence for inner wall
interaction on the TV camera.

Next shot. Move the lower x-point 2 mm out. To take the plasma off of the
inner wall.
Increased RXL by 3 mm throughout the shot.

Decrease both inner and outer gap by 2mm.
Reduced clearin by 2 mm.


003. Plasma.

Next shot,
Reduced clearin by 2 mm
Increased rxl by 2 mm throughout the shot.


004. Plasma.

Next shot. Reduced Clearin again. This time simply moved the changes to earlier
time.

005. Plasma

Next shot. Increased clearin by 1 mm,

006. Plasma.

Next shot. Increase clearin by 1 mm. The clearin changes are made at the
request of the probe-folk.
Moved the DNB firing time to 0.8 s at the request of the session leader.


007. Plasma

Next shot. No changes.

008. Plasma

Next shot. DN. Only turned off segment 2 and turned on segment 4 with the
expectation that we will end up with the optimum DN from 1031124.

009. Plasma. Disrupted during the ramp down; 1.6 s
This shot had an ssep scan.

Next shot. Reloaded segment 4 from shot 1031124015.
Reduced the density request nl04 to 0.8e+19
Next shot: Increased clearin by 2 mm for probes


010. DN but was lower null until 1s.

Next shot. Changed ssep gain to achieve DNB sooner


011. More strongly lower null.

Next shot. Increased ssep by 2 mm

012. DN but went toward SNU later.

Next shot. Changed the programming for SSEP. Scanning it to keep it in DN
throughout the shot

013. SN.

Next shot. Ssep programming changed again to move more toward DN

014. DN. Tending toward SNL.

Next shot. No pcs changes.

015. Fizzle.

Next shot. No changes.

016, Plasma

Next shot. No changes

017. Plasma.

Next shot. No pcs changes

018. Plasma

Next shot. Add 2mm to ssep.

019. Plasma
Upper null thought the change in ssep was small.

Next shot.
Switch to upper null.
Reload segment 3 from 1031124029
Close segment 4 and open segment 3

020. Plasma

Next shot. No pcs changes

021. Plasma

Next shot. No pcs changes

022. Plasma

Next shot. No pcs changes

023. Plasma.

Next shot. No pcs changes

024. Plasma

Next shot. No pcs changes

025. Plasma. Disruption at 0.86 s.
UFO from location of probe at time of disruption.

Next shot. Increased the inner gap by 1 mm. Increased clearin by 1 mm.

026, Fizzle

Next shot. Add 2 ms to the prepuff

027. Plasma. Disruption at 0.87 s
This is the time of the probe plunge.

Next shot. No pcs changes. F-port will not be reciprocated.


028. Fizzle

Next shot. No pcs changes.


029. Fizzle

Next shot. Reduced the prefill by 2 ms to the original value on shot 025 and
previous.

030. Plasma

Next shot. Inner wall limited
reloaded 1030701019 segment 2 into segment 3
changed the a-coil to 2500 A as for other shots today
changed the Ip to 800 kA
changed nel04 request to 0.8e+19

031. Dud.
Power supply problem. See engineering log.

032. No power shot because of a data system hang.


033. Plasma.
Inner wall limited.

Last shot.



























Session Leader Comments
Nov 25 2003 09:57:23:890AM1031125003Amanda HubbardFlat RF at 0.9 MW. L-H happened earlier than expected; 0.774 s.

GPC not working, unfortunately.

next shot, lower the power to 0.7 MW.
Nov 25 2003 10:44:01:050AM1031125005Amanda HubbardFlat RF at 0.85 MW. Perfect L-H threshold shot, with transition at 1.029 s, just before high power ramp.

Will repeat for more probe data.
Nov 25 2003 10:54:26:950AM1031125006Amanda HubbardVery similar to shot 5; ;late L-H, good threshold data. IW gap a bit small for Brian.

Nov 25 2003 10:57:20:553AM1031125007Amanda HubbardSame RF (0.82 MW). L-H happens earlier for some reason. H-mode 0.75-0.9 secs, then L-mode; another H in
high power period.

Brian happy with probe data. Repeat once more with power slightly lower, for probes.

Nov 25 2003 11:19:41:827AM1031125008Amanda Hubbard
. . . . . . . . . . . . . . . . . . . .
0.75 MW. Still an early L-H transition for some reason, but an L-mode period following. Got IW probe data.

Next shot: Go to Double null, starting with shape from 1124. May tweak it some for ETS.

RF will start at 0.85 MW (the LSN threshold), then ramp up.

-
Nov 25 2003 11:17:40:970AM1031125009Amanda Hubbard
SSep was scanned LSN to USN.

Late H-mode at 1.33 secs, 4.4 MW. (slightly upper null at the time.)
Nov 25 2003 01:29:21:013PM1031125011Amanda Hubbard
Near DN , but ssep ~ -0.18.

L-H at 1.03 s, 1.7 MW

Keep trying for balanced DN.
Nov 25 2003 12:54:41:727PM1031125012Amanda Hubbard
Very near DN (ssep + 0.08 cm). L-H at 1.05 s, 1.7 MW RF, Te9 140 eV (at r/a 0.945)

Nov 25 2003 12:55:18:117PM1031125012Amanda Hubbard
Very near DN (ssep + 0.08 cm). L-H at 1.05 s, 1.7 MW RF, Te9 140 eV (at r/a 0.945)

Nov 25 2003 12:30:35:077PM1031125013Amanda HubbardSsep now slightly towards LSN (-0.17 cm).

L-H at 1.02 s, 1.6 MW. Te9 ~ 160 eV. Note small injection at 1 sec, just before L-H (might affect Pthresh).

Nov 25 2003 12:48:26:003PM1031125014Amanda Hubbard
Very near DN (ssep - 0.08 cm). L-H at 1.07 s, 2 MW RF, Te9 190 eV (at r/a 0.94)

Nov 25 2003 01:15:14:570PM1031125016Amanda Hubbard
Near DN (Ssep -0.2 to 0.1).

Started with flat 2 MW RF, as requested, then ramps up.
Got series of H-modes, starting rather early (0.79 s, Te9 ~ 170 eV).

Reduce RF power next shot to try to delay H-mode

Nov 25 2003 01:20:39:297PM1031125017Amanda Hubbard
Near DN (Ssep -0.2 to 0.1).

1.8 MW. However, L-H happens even earlier (go figure). 0.78 secs,

Reduce power further next shot.
Nov 25 2003 01:47:11:610PM1031125018Amanda HubbardGood. 1.6 MW. Delayed L-H transition to 0.86 secs. This appears to be the effective threshold.
Jerry and Brian have profiles.

Note plasma is dithering before sustained L-H; Te rising slowly.
Te9 = 170 eV at start of dithers, 230 eV at sustained LH.

Next shot, raise Ssep by 2mm, just to make sure we really are DN. Will transition be delayed?
Nov 25 2003 02:10:55:823PM1031125019Amanda HubbardSsep +0.2 cm. Marginally upper null.
As predicted by some, L-H transition is indeed significantly delayed. No H0mode at 1.6 MW.

L-H in fast ramp, 1.15 s, 3.0 MW, interestingly, Te9 still 160 eV. (at r/a 0.95)

Declare DN part (Step 3 of plan) complete; if time we'll come back and map out Pthresh vs Ssep
since it appears to be a steep function.

Moving to Upper Null, starting with shape from 1031124029.
Nov 25 2003 02:42:20:370PM1031125020Amanda Hubbard
Nice Upper Null discharge.

RF, as requested, did constant 810 kW until 0.95 s, then ramped to 5 MW.
4 MW
L-H at 1.29 s, 4 MW (much higher than LSN or DN).

Te9=350 eV, also higher. Note that Te9 increases non-linearly starting ~ 1.2 secs.

Repeat.
-
Nov 25 2003 02:49:57:873PM1031125020Amanda HubbardRepeat of 21. Nice clean RF trace. Still late L-H , Pthresh ~ 3.7 MW.

Brian gets good probe data in low power L-mode.

Next shot, raise initial RF to 3.5 MW to scope out Pthresh, measure profiles.
Nov 25 2003 02:41:18:920PM1031125021Amanda HubbardNice Upper Null discharge.

Similar RF trace, up to 5.3 MW. Monster sawtooth before L-H, 5 keV, 50+ msecs.

Repeat one more time for probes.
Nov 25 2003 03:04:25:103PM1031125023Amanda HubbardStart with Prf=3.6 MW. Transitions quite quickly to H-mode. 0.79 secs, Te9 ~ 230 eV.

Repeat with less power, try to delay L-H.
Nov 25 2003 03:11:21:670PM1031125024Amanda HubbardEarly Prf=3.2 MW. Transitions to H-mode at 0.81 secs, Te9 ~ 280 eV.
Note edge Te ratcheting up pre-LH, steps at each sawtooth. Might have something to do with the variable Pthresh

Repeat with even less power, try to delay L-H.
Nov 25 2003 03:25:08:243PM1031125025Amanda HubbardPrf= 2.9 MW. Disrupts, likely due to probe, at 0.85 secs.

L-mode, Te9 still increasing slowly up to ~ 200 eV. Repeat.
Nov 25 2003 03:54:47:023PM1031125027Amanda HubbardPrf= 2.9 MW. USN Disrupts again at likely due to probe, at 0.855 secs.
L-mode again. Note nel decreasing 0.72-0.85 secs., Te9 increasing from 0.8 secs. Why?
Repeat, without F-side probe.
Nov 25 2003 04:37:45:973PM1031125030Amanda HubbardPrf= 2.9 MW. Plasma, full length. This time, get an L-H transition at 0.83 secs.
Rather short L-mode period; a longer L-mode period 1-1.1 secs before next LH at 1.1, just before the RF
ramp.

Given the time, this will be our threshold shot.

Next shot, try for inner wall limited.

Physics Operator Comments
Nov 25 2003 08:00:15:437AMBill RowanEngineering Setup and Run Plan for 11/25/03

MP #363 LH Threshold
Session Leader: Hubbard

Physics operator: Rowan

ECDC in D2 at 2e-4 Torr, stopping by 07:00.
Bake at 60 C as well.

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

Power systems the same as on 1031124033

A-coils should be hooked up as on 1031124033 (+Dtop -Dbot -Jtop +Jbot).
Enable the power supply.

Gas setup:
fill B-Top with 6 psi D2 Hybrid enabled (PG4)
fill B-side lower with 1 psi Ar Hybrid enabled (PG1)
leave B-side upper as is Hybrid DISABLED (PG2)
fill C-side with 30 psi D2 Hybrid enabled (PG3)

Enable the following gate valves, assuming no vacuum problems:
ECE, VUV, DNB


RF Setup:Transmitters 1,2,3 & 4 in Run On by 08:00.

___________________________________________________-

MP#363 LH Threshold

Run Plan for MP 363

Optimum shape for USN plasmas was established during run 1031124.

Continue with point 2 from the miniproposal:


2) Switch to LSN. 800 kA, ~ 5.4 T. 3-4 shots.
a) Power ramp up to ~ 3 MW, to determine L-H threshold.
b) Discharge with fixed power just below threshold, for 100-200 ms, followed by
high power phase (4-5 MW). Repeat as needed for probe, HIREX.

3) Switch to DN. 5-6 discharges.
a) 2 Discharges at power which gave L-H threshold in LSN (eg. 1 MW). Document
ETS profiles, flows, rotation.
b) Power ramp to maximum available (5 MW>) to determine the new L-H threshold.
c) As above, make discharges with power just below L-H transition for ~ 200 ms,
followed by higher power to get H-mode phase.

4) Switch to USN. 5-6 discharges
a) 2 Discharges at power which gave L-H threshold in LSN (eg. 1 MW). Document
ETS profiles, flows, rotation.
b) Power ramp to maximum available (5 MW>) to determine the new L-H threshold.
(from prior experience, expect ~ 3.5 MW)
c) As above, make discharges with power just below L-H transition for ~ 200 ms,
followed by higher power to get H-mode phase (eg. 3.5, 5 MW).

5) Switch to Inner wall limited. Repeat sequence. 5-6 discharges.
a) 2 Discharges at power which gave L-H threshold in LSN (eg. 1 MW). Document
ETS profiles, flows, rotation.
b) Power ramp to maximum available (5 MW>) to determine whether an H-mode is
achievable. From prior experiments, expect to need at least 4 MW. If yes,
document profiles at L-H threshold, as above, and in H-mode. If no, document at
highest available RF power to set lower bound on edge Te, rotation etc.
Nov 25 2003 09:02:07:320AMBill Rowan001. Dud. The DNB gate valve was enabled and the DNB was in a cryo frosting cycle with N2 at 10e-04 T.
Will take this to be the cause of the dud as this setup produced a 1.4 s on the last shot yesterday and
a fizzle on the next to last shot.

Next shot. Disable DNB gate valve and the DNB PLC. No PCS changes.
Nov 25 2003 09:02:46:290AM1031125001Bill Rowan001. Dud. The DNB gate valve was enabled and the DNB was in a cryo frosting cycle with N2 at 10e-04 T.
Will take this to be the cause of the dud as this setup produced a 1.4 s on the last shot yesterday and
a fizzle on the next to last shot.

Next shot. Disable DNB gate valve and the DNB PLC. No PCS changes.
Nov 25 2003 09:16:20:233AM1031125002Bill Rowan002. Plasma. No disruption at 1.4 as we had yesterday. Evidence for inner wall interaction on
the TV camera.

Next shot. Move the lower x-point 2 mm out. To take the plasma off of the inner wall.
Increased RXL by 3 mm throughout the shot.
Nov 25 2003 09:47:28:723AM1031125002Bill RowanDecrease both inner and outer gap by 2mm.
Reduced clearin by 2 mm.
Nov 25 2003 09:59:28:007AM1031125003Bill Rowan003. Plasma.

Next shot,
Reduced clearin by 2 mm
Increased rxl by 2 mm throughout the shot.
Nov 25 2003 10:14:49:220AM1031125004Bill Rowan004. Plasma.

Next shot. Reduced Clearin again. This time simply moved the changes to earlier time.
Nov 25 2003 10:22:21:320AM1031125005Bill Rowan005. Plasma

Next shot. Increased clearin by 1 mm,
Nov 25 2003 10:36:03:387AM1031125006Bill Rowan006. Plasma.

Next shot. Increase clearin by 1 mm. The clearin changes are made at the request of
the probe-folk.
Nov 25 2003 10:38:58:800AM1031125006Bill RowanNext shot: Moved the DNB firing time to 0.8 s at the request of the session leader.
Nov 25 2003 10:53:13:887AM1031125007Bill Rowan007. Plasma

Next shot. No changes.
Nov 25 2003 11:02:44:817AM1031125008Bill Rowan008. Plasma

Next shot. DN. Only turned off segment 2 and turned on segment 4 with the
expectation that we will end up with the optimum DN from 1031124.
Nov 25 2003 11:22:50:057AM1031125009Bill Rowan009. Plasma. Disrupted during the ramp down; 1.6 s
This shot had an ssep scan.

Next shot. Reloaded segment 4 from shot 1031124015.
Reduced the density request nl04 to 0.8e+19


Nov 25 2003 11:25:10:910AM1031125009Bill Rowan

Next shot: Increased clearin by 2 mm for probes
Nov 25 2003 11:47:27:893AM1031125010Bill Rowan010. DN but was lower null until 1s.

Next shot. Changed ssep gain to achieve DN sooner
Nov 25 2003 11:56:02:397AM1031125011Bill Rowan011. More strongly lower null.

Next shot. Increased ssep by 2 mm
Nov 25 2003 12:11:40:573PM1031125012Bill Rowan012. DN but went toward SNU later.

Next shot. Changed the programming for SSEP. Scanning it to keep it in DN throughout
the shot
Nov 25 2003 12:26:09:287PM1031125013Bill Rowan013. SN.

Next shot. Ssep programming changed again to move more toward DN
Nov 25 2003 12:38:23:673PM1031125014Bill Rowan014. DN. Tending toward SNL.

Next shot. No pcs changes.
Nov 25 2003 12:54:14:243PM1031125015Bill Rowan015. Fizzle.

Next shot. No changes.
Nov 25 2003 01:05:51:990PM1031125016Bill Rowan016, Plasma

Next shot. No changes
Nov 25 2003 01:21:00:327PM1031125017Bill Rowan017. Plasma.

Next shot. No pcs changes
Nov 25 2003 01:35:12:070PM1031125018Bill Rowan018. Plasma
Nov 25 2003 01:41:09:480PM1031125018Bill Rowan018. Plasma

Next shot. Add 2mm to ssep.
Nov 25 2003 02:09:53:123PM1031125019Bill Rowan019. Plasma
Upper null thought the change in ssep was small.

Next shot.
Switch to upper null.
Reload segment 3 from 1031124029
Close segment 4 and open segment 3
Nov 25 2003 02:32:48:323PM1031125020Bill Rowan020. Plasma

Next shot. No pcs changes
Nov 25 2003 02:33:18:917PM1031125020Bill Rowan021. Plasma

Next shot. No pcs changes
Nov 25 2003 02:48:11:487PM1031125022Bill Rowan022. Plasma

Next shot. No pcs changes
Nov 25 2003 03:03:10:683PM1031125023Bill Rowan023. Plasma.

Next shot. No pcs changes
Nov 25 2003 03:13:49:963PM1031125024Bill Rowan024. Plasma

Next shot. No pcs changes
Nov 25 2003 03:28:14:643PM1031125025Bill Rowan025. Plasma. Disruption at 0.86 s.
UFO from location of probe at time of disruption.

Next shot. Increased the inner gap by 1 mm. Increased clearin by 1 mm.
Nov 25 2003 03:34:39:337PM1031125026Bill Rowan026, Fizzle

Next shot. Add 2 ms to the prepuff
Nov 25 2003 03:51:34:013PM1031125027Bill Rowan027. Plasma. Disruption at 0.87 s
This is the time of the probe plunge.

Next shot. No pcs changes. F-port will not be reciprocated.
Nov 25 2003 04:00:30:453PM1031125028Bill Rowan028. Fizzle

Next shot. No pcs changes.
Nov 25 2003 04:12:40:233PM1031125029Bill Rowan029. Fizzle

Next shot. Reduced the prefill by 2 ms to the original value on shot 025 and previous.
Nov 25 2003 04:34:17:357PM1031125030Bill Rowan030. Plasma

Next shot. Inner wall limited
reloaded 1030701019 segment 2 into segment 3
changed the a-coil to 2500 A as for other shots today
changed the Ip to 800 kA
changed nel04 request to 0.8e+19
Nov 25 2003 04:42:08:950PM1031125031Bill Rowan031. Dud.
Power supply problem. See engineering log.
Nov 25 2003 05:04:04:857PM1031125032Bill Rowan032. No power shot because of a data system hang.
Nov 25 2003 05:04:31:167PM1031125033Bill Rowan033. Plasma.
Inner wall limited.

Last shot.

Engineering Operator Comments
ShotTimeTypeStatusComment
108:54:02:347AMPlasmaOk
209:06:28:363AMPlasmaOk
309:51:04:140AMPlasmaOk
410:03:40:237AMPlasmaOk
510:17:00:663AMPlasmaOk
610:29:29:823AMPlasmaOk
710:42:11:073AMPlasmaOk
810:54:45:560AMPlasmaOk
911:08:38:350AMPlasmaOk
1011:26:31:613AMPlasmaOk
1111:48:45:640AMPlasmaOk
1212:04:11:930PMPlasmaOk
1312:16:52:427PMPlasmaOk
1412:30:22:467PMPlasmaOk
1512:45:57:490PMPlasmaOk
1601:01:07:547PMPlasmaOk
1701:14:02:447PMPlasmaOk
1801:31:00:743PMPlasmaOk
1901:51:29:370PMPlasmaOk
2002:10:51:230PMPlasmaOk
2102:25:02:333PMPlasmaOk
2202:37:53:080PMPlasmaOk
2302:50:42:640PMPlasmaOk
2403:04:02:570PMPlasmaOk
2503:16:42:787PMPlasmaOk
2603:30:06:407PMPlasmaOk
2703:42:44:153PMPlasmaOk
2803:55:24:383PMPlasmaOk
2904:08:10:723PMPlasmaOk
3004:20:49:110PMPlasmaOk
3104:35:11:337PMPlasmaBadOH2 comm fault @ 0.07sec
3304:58:26:800PMPlasmaOk