Alcator C-Mod Run 1040330 Information

Back to runs

Miniproposals
Miniproposal:380
Date Filed:12/19/2003
Title:Influence of ICRF on sawtooth behavior
First Author:Steve Wukitch
Session Leader:Steve Wukitch (shots 1-39)

Operators
Session leader(s):Steve Wukitch
Physics operator(s):Steve Wolfe
Engineering operator(s):Gary Dekow,Ed Fitzgerald,Bill Parkin

Engineering Operator Run Comment
MP#380 Sawtooth Effect; SL:Wukitch; PO:Wolfe; EO:Dekow/Fizt/Parkin

Session Leader Plans

Physics Operators Plans

Session Leader Summaries
Entered: Jul 7 2004 03:49:04:193PM
Author: Steve Wukitch
Session leader: S. Wukitch
Physics operator: S.M. Wolfe


ECDC Overnight in D2, stopping by 07:00
Run begins at 09:00 and ends at 17:00.

Power systems the same as 1040218003

A-coils as on 1040218003.

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: Transmitters #1,2,3 and 4 in RUN-ON by 08:30
-----------------------------------------------------------------------------------
Run plan:

The goal of this mini-proposal is to investigate role of fast particle
pressure and ion cyclotron current drive in modifying the sawtooth
period.

Start with 1040218003 (Fiducial) - 1 MW steps in RF to 4 MW
5.4 T, 1 MA, nl_04~0.8

With square RF pulse, vary J antenna phase for central deposition
(3 shots) [USN (1040218025), BT~5.2 T, Ip ~ 1 MA, nl_04~0.8]

During a discharge, ramp B-field to scan the cyclotron resonance
across the q=1 on both the high field and low field side for co-,
ctr-, and heating phase. (6 shots)

Place minority resonance near the q=1 surface on both the high field
side and low field side for co-, ctr-, and heating phase with 4.5 MW
of ICRF. (6 shots)

Scan RF power for central deposition in H-mode for co-, ctr-, and
heating (2.5 MW from D and E)

Scan RF power for central deposition in L-mode for co-, ctr-, and
heating (J-port compared to D and E)

At high power scan current with central deposition (0.6, 0.8, 1, 1.2 MA)

-----------------------------------------------------------------------------------
001-004 cycle shots

005 Fiducial (1 MA, BT~5.4 T, nl04~0.85)
D: 0.5,1 MW [0.6,1.5]sec
E: 0.5,1 MW [0.6,1.5]sec
J: 1,2 MW [0.6,1.5]sec
result: plasma - H-mode
D: ran 1 fault
E: ran 1 fault
J: max faults
006 Fiducial (1 MA, BT~5.4 T, nl04~0.85)
D: 0.5,1 MW [0.6,1.5]sec
E: 0.5,1 MW [0.6,1.5]sec
J: 1,2 MW [0.6,1.5]sec
result: plasma - H-mode
D: ran 2 faults
E: ran 6 faults
J: max faults
007 Fiducial (1 MA, BT~5.4 T, nl04~0.85)
D: 0.5,1 MW [0.6,1.5]sec
E: 0.5,1 MW [0.6,1.5]sec
J: 1,2 MW [0.6,1.5]sec
result: plasma - H-mode
D: ran 1 fault
E: ran
J: max faults - much closer on the match
next shot: repeat
008 Fiducial (1 MA, BT~5.4 T, nl04~0.85)
D: 0.5,1 MW [0.6,1.5]sec
E: 0.5,1 MW [0.6,1.5]sec
J: 1,2 MW [0.6,1.5]sec
result: plasma - H-mode
D: ran
E: ran 1 fault
J: ran max faults
next shot: repeat - let J clean up a bit
009 Fiducial (1 MA, BT~5.4 T, nl04~0.85)
D: 0.5,1 MW [0.6,1.5]sec
E: 0.5,1 MW [0.6,1.5]sec
J: 1,2 MW [0.6,1.5]sec
result: plasma - H-mode
D: ran 1 fault
E: ran
J: ran
next shot: move to USN for phase scan w central deposition
010 USN, 1 MA, BT~5.2 T, nl04~0.85
D: 0.5,1 MW [0.7,1.5]sec
E: 0.5,1 MW [0.7,1.5]sec
J: 2.5 MW ramp [0.8,1.5]sec
result: plasma - H-mode
D: ran max fault
E: ran
J: ran 2 faults
next shot: IWL, lower density to 0.8
011 IWL, 1 MA, BT~5.2 T, nl04~0.8
D: 0.5,1 MW [0.7,1.3]sec
E: 0.5,1 MW [0.7,1.3]sec
J: 2.5 MW ramp [0.8,1.3]sec
result: plasma - H-modes
D: ran 4 faults
E: ran 4 faults
J: ran overload on #3 at L->H
next shot: IWL, less RF power
012 IWL, 1 MA, BT~5.2 T, nl04~0.8
D: 0.5,1 MW [0.7,1.3]sec
E: 0.5,1 MW [0.7,1.3]sec
J: 2.5 MW ramp [0.8,1.3]sec
result: early disruption
013 IWL, 1 MA, BT~5.2 T, nl04~0.8
D: 0.5,1 MW [0.7,1.3]sec
E: -
J: 2.5 MW ramp [0.8,1.3]sec
result: plasma
D: ran
J: ran overload on #3 at late L->H
next shot: lower density to 0.7
014 IWL, 1 MA, BT~5.2 T, nl04~0.8
D: 1 MW [0.7,1.3]sec
E: -
J: 2.5 MW ramp [0.8,1.3]sec
result: plasma
D: ran
J: ran 4 faults
next shot: decrease D antenna to 0.6
015 IWL, 1 MA, BT~5.2 T, nl04~0.8
D: 1 MW [0.7,1.3]sec
E: -
J: 2.5 MW ramp [0.8,1.3]sec
result: plasma
D: ran
J: ran 1 fault
next shot: change phase to +220
016 IWL, 1 MA, BT~5.2 T, nl04~0.8
D: 1 MW [0.7,1.3]sec
E: -
J: 2.5 MW ramp [0.8,1.3]sec, phase is +220 (co-current)
result: plasma
D: ran
J: ran 4 faults
next shot: change phase to +30
017 IWL, 1 MA, BT~5.2 T, nl04~0.8
D: 1 MW [0.7,1.3]sec
E: -
J: 2.5 MW ramp [0.8,1.3]sec, phase is +30 (ctr-current)
result: plasma
D: ran
J: ran 3 faults
next shot: scan BT from 5.2->4.8 T
018 IWL, 1 MA, BT~5.2->4.8 T, nl04~0.8
D: 1 MW [0.7,1.3]sec
E: -
J: 2.5 MW ramp [0.8,1.3]sec, phase is +30 (ctr-current)
result: plasma
D: ran
J: ran max faults
next shot: repeat
019 IWL, 1 MA, BT~5.2->4.8 T, nl04~0.8
D: 1 MW [0.7,1.3]sec
E: -
J: 2.5 MW ramp [0.8,1.3]sec, phase is +30 (ctr-current)
result: plasma
D: ran
J: ran max faults
next shot: repeat with lower RF power
020 IWL, 1 MA, BT~5.2->4.8 T, nl04~0.8
D: 1 MW [0.7,1.3]sec
E: -
J: 2.3 MW ramp [0.8,1.3]sec, phase is +30 (ctr-current)
result: plasma
D: ran
J: ran 4 faults
~1.2 sec sawteeth become longer for two periods (13 msec -> 19 msec)
next shot: repeat
021 IWL, 1 MA, BT~5.2->4.8 T, nl04~0.8
D: 1 MW [0.7,1.3]sec
E: -
J: 2.3 MW ramp [0.8,1.3]sec, phase is +30 (ctr-current)
result: plasma
D: ran
J: ran 4 faults
Again there is a change is ST period around 1.2-1.25 sec
022 IWL, 1 MA, BT~5.2->4.8 T, nl04~0.8
D: 1 MW [0.7,1.3]sec
E: -
J: 2.3 MW ramp [0.8,1.3]sec, phase is +220 (co-current)
result: plasma
D: ran
J: ran 4 faults
Again there is a change is ST period around 1.2-1.25 sec
023 early disruption
024 IWL, 1 MA, BT~5.2->4.8 T, nl04~0.8
D: 1 MW [0.7,1.3]sec
E: -
J: 2.3 MW ramp [0.8,1.3]sec, phase is +130 (heating)
result: plasma
D: ran
J: ran 1 fault
transition in sawtooth period around 1.38 sec - J antenna crossing
earlier transition is associated with D antenna
025 early disruption
026 IWL, 1 MA, BT~5.1->4.9 T, nl04~0.8
D: 1 MW [0.7,1.3]sec
E: -
J: 2.3 MW ramp [0.8,1.3]sec, phase is +130 (heating)
result: plasma - early disruption
D: ran
J: ran
027 NTP
028 IWL, 1 MA, BT~5.1->4.9 T, nl04~0.8
D: 0.6 MW [0.6,1.3]sec
E: -
J: 2.3 MW ramp [0.7,1.3]sec, phase is +130 (heating)
result: plasma
D: ran
J: ran 2 faults
no change in the ST - field ramped only to ~5 T
029 IWL, 1 MA, BT~5.1->4.9 T, nl04~0.8
D: 0.6 MW [0.6,1.3]sec
E: -
J: 2.3 MW ramp [0.7,1.3]sec, phase is +130 (heating)
result: plasma
D: ran
J: ran 1 fault
next shot: rampdown and rampup on B-field
030 IWL, 1 MA, BT~5.1->4.9 T, nl04~0.8
D: 0.6 MW [0.6,1.3]sec
E: -
J: 2.3 MW ramp [0.7,1.3]sec, phase is +130 (heating)
result: plasma
D: ran
J: ran 1 fault
next shot: repeat with different antenna phase
031 early disruption
032 IWL, 1 MA, BT~5.1->4.9 T, nl04~0.8
D: 0.6 MW [0.6,1.3]sec
E: -
J: 2.3 MW ramp [0.7,1.3]sec, phase is +220 (co-current)
result: plasma
D: ran
J: ran 1 fault
next shot: repeat with different antenna phase
033 NTP
034 IWL, 1 MA, BT~5.1->4.9 T, nl04~0.8
D: 0.6 MW [0.6,1.3]sec
E: -
J: 2.3 MW ramp [0.7,1.3]sec, phase is +30 (ctr-current)
result: plasma
D: ran
J: ran 3 faults
next shot: lower Ip=0.8 MA
035 IWL, 1 MA, BT~5.1->4.9 T, nl04~0.8
D: 0.6 MW [0.6,1.3]sec
E: -
J: 2.3 MW ramp [0.7,1.3]sec, phase is +30 (ctr-current)
result: plasma
D: ran
J: ran

Run Summary

Primarily focussed on B-field scans at 1 MA to investigate the impact
of antenna phase on sawtooth period. There did not appear to be a
strong impact on the sawtooth period for the B-field sweep performed
for any antenna phase at 1 MA. For 1 MA, the sawtooth period was
similar for central deposition for all antenna phases. This is in
contrast to the 0.8 MA results where the sawtooth period is sensitive
to antenna phase (see 1030710005-007, 1040218, and 1040331035). In
addition a set of modes were observed on PCI and magnetics. The modes
observed by the PCI were 700-750 kHz, appeared during the flat top of
each ST and insensitive to antenna phase. The modes vanished for
off-axis deposition and 0.8 MA discharges. These modes may be a core
localized Alfven mode (energetic particle or resonant toroidal Alfven
eigenmode).

Physics Operator Summaries
Entered: Jul 7 2004 04:36:49:710PM
Author: Steve Wolfe
Physics Operator Summary for Tues. 1040330

MP#380 ICRF Sawtooth Effects
SL: Wukitch
PO: wolfe
EO: Dekow, Fitzgerald, Byford, Parkin

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

ECDC Overnight in D2, stopping by 07:00
Run begins at 09:00 and ends at 17:00.

Power systems the same as 1040218003

A-coils as on 1040218003.

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: Transmitters #1,2,3 and 4 in RUN-ON by 08:30
-----------------------------------------------------------------------------------
Run plan:

The goal of this mini-proposal is to investigate role of fast particle
pressure and ion cyclotron current drive in modifying the sawtooth
period.

Start with 1040218003 (Fiducial) - 1 MW steps in RF to 4 MW
5.4 T, 1 MA, nl_04~0.8

With square RF pulse, vary J antenna phase for central deposition
(3 shots) [USN (1040218025), BT~5.2 T, Ip ~ 1 MA, nl_04~0.8]

During a discharge, ramp B-field to scan the cyclotron resonance
across the q=1 on both the high field and low field side for co-,
ctr-, and heating phase. (6 shots)

Place minority resonance near the q=1 surface on both the high field
side and low field side for co-, ctr-, and heating phase with 4.5 MW
of ICRF. (6 shots)

Time permitting:

Scan RF power for central deposition in H-mode for co-, ctr-, and
heating (2.5 MW from D and E)

Scan RF power for central deposition in L-mode for co-, ctr-, and
heating (J-port compared to D and E)

At high power scan current with central deposition (0.6, 0.8, 1, 1.2 MA)

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

Results:

Data system problems on the first few test shots, which were begun before 8:00
for TF scanner and DNB CAMAC testing. Apparently the DPCS Computer cmodws36
needed to be rebooted again. Shot#4 was a successful test cycle, and the first
plasma shot was #5.

I set up PCS with the fiducial in seg2 and the upper null shot in seg3; we
began with the fiducial (seg2) on. The fiducials/conditioning went very well,
and we began the MP on shot 10.

We started with the upper null in segment 3, but got H-modes so we loaded a
limiter discharge, 1040218024, into segment 4, adjusted the current to 1MA and
the density to 0.7e20 and tried that. It also went into H-mode, at <4MW, so it
was necessary to lower the power to stay in L-mode

The limiter equilibrium from shot 1040218024 had a funny asymmetric shape,
because it was derived from an upper null case. On shot 12 I adjusted the
xpoint locations to symmetrize it. For shot#14 we decreased the elongation,
but it still was close to going into H-mode!

Variation of antenna phasing began on shot#15-17. For shot 18 we started the
B-field ramping, sweeping from 5.2 to 4.8T. For these we increased the pulse
length back to 1.5sec EOF. This resulted in some vertical thrashing after
1.3sec, apparently because the oh2's went to their current rails (set at
26). For shot 19 the oh2 limits were raised to 32kA, which fixed the vertical
thrash. The ramp was adjusted on shot#26 and again on #29; to get the
requested ramp rates and final value it was necessary to make stepwise
transitions and overshoot the final point in the programmed waveform. The
antenna phase was adjusted again between shot #30 and 34. The last plasma
shot #35 was at reduced current of 800kA.

We had a lot of early disruptions, usually shortly after segment switch, as
well as a number of injections with current loss at this time. There is
clearly a large thrash associated with this time, but I was unable to get rid
of it. It seems that runaways exacerbate the problem, but are not
fundamental. I tried changing the current and rcur programs around the switch
without permanent success, though sometimes it seemed to have helped for a
shot or two. I also delayed the gain switches on the zcur3 to try to stop the
chopper from flooring, but this seemed to have no effect. There are
substantial initial errors on clearin and the xpoint locations; it is likely
that these are causing the thrashing. I did not get to try changing this
programming to see if it helped. It is also possible that the segment switch
is a red herring, and we just are running to fast a current ramp and getting
MHD effects. Additional complicating effects are that this equilibrium was
using a clearin predictor based on the upper null location, with no offset
value, so it may have a current sensitivity; the oh1 and oh2U/L crowbars are
at .12sec, which is clearly after the initial thrash but may contribute to
some of the problem; and ef4 is going through crossover right at the same
time.

Aside from the disruptions, and a couple of fizzles, the plasma ran pretty
well. I was chasing the pre-puff all day to try to control the runaways, and
got up to 25msec by the end of the day. I made one BR0 tweak, from 0.0 to
+.0005T following one of the fizzles; this brought the BR0 predictor to
between -.001 and -.0015T, and seemed to be an improvement.

Early in the run the RF power was causing significant density increases. By
shot 20 or so this had pretty much cleaned up.

Scorecard
----------

Tests 4
Duds 0
Fizzles 2
Plasmas 29 (4 current rise disruptions)
------ --
Total 35

After the run Tommy and Willy took a number of additional test shots to debug
the TF scanner.

Session Leader Comments
Mar 30 2004 09:31:18:013AMSteve WukitchSession leader: S. Wukitch
Physics operator: S.M. Wolfe


ECDC Overnight in D2, stopping by 07:00
Run begins at 09:00 and ends at 17:00.

Power systems the same as 1040218003

A-coils as on 1040218003.

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: Transmitters #1,2,3 and 4 in RUN-ON by 08:30
-----------------------------------------------------------------------------------
Run plan:

The goal of this mini-proposal is to investigate role of fast particle
pressure and ion cyclotron current drive in modifying the sawtooth
period.

Start with 1040218003 (Fiducial) - 1 MW steps in RF to 4 MW
5.4 T, 1 MA, nl_04~0.8

With square RF pulse, vary J antenna phase for central deposition
(3 shots) [USN (1040218025), BT~5.2 T, Ip ~ 1 MA, nl_04~0.8]

During a discharge, ramp B-field to scan the cyclotron resonance
across the q=1 on both the high field and low field side for co-,
ctr-, and heating phase. (6 shots)

Place minority resonance near the q=1 surface on both the high field
side and low field side for co-, ctr-, and heating phase with 4.5 MW
of ICRF. (6 shots)

Scan RF power for central deposition in H-mode for co-, ctr-, and
heating (2.5 MW from D and E)

Scan RF power for central deposition in L-mode for co-, ctr-, and
heating (J-port compared to D and E)

At high power scan current with central deposition (0.6, 0.8, 1, 1.2 MA)
Mar 30 2004 09:32:38:920AM1040330005Steve WukitchFirst shot since switch back to 78 MHz

005 Fiducial (1 MA, BT~5.4 T, nl04~0.85)
D: 0.5,1 MW [0.6,1.5]sec
E: 0.5,1 MW [0.6,1.5]sec
J: 1,2 MW [0.6,1.5]sec
result: plasma - H-mode
D: ran 1 fault
E: ran 1 fault
J: max faults
Mar 30 2004 09:35:38:863AM1040330006Steve Wukitch006 Fiducial (1 MA, BT~5.4 T, nl04~0.85)
D: 0.5,1 MW [0.6,1.5]sec
E: 0.5,1 MW [0.6,1.5]sec
J: 1,2 MW [0.6,1.5]sec
result: plasma - H-mode
D: ran 2 faults
E: ran 6 faults
J: max faults
Mar 30 2004 09:50:58:960AM1040330007Steve Wukitch007 Fiducial (1 MA, BT~5.4 T, nl04~0.85)
D: 0.5,1 MW [0.6,1.5]sec
E: 0.5,1 MW [0.6,1.5]sec
J: 1,2 MW [0.6,1.5]sec
result: plasma - H-mode
D: ran 1 fault
E: ran
J: max faults - much closer on the match
next shot: repeat
Mar 30 2004 09:56:39:760AM1040330008Steve Wukitch008 Fiducial (1 MA, BT~5.4 T, nl04~0.85)
D: 0.5,1 MW [0.6,1.5]sec
E: 0.5,1 MW [0.6,1.5]sec
J: 1,2 MW [0.6,1.5]sec
result: plasma - H-mode
D: ran
E: ran 1 fault
J: ran max faults
next shot: repeat - let J clean up a bit
Mar 30 2004 10:19:41:820AM1040330009Steve Wukitch009 Fiducial (1 MA, BT~5.4 T, nl04~0.85)
D: 0.5,1 MW [0.6,1.5]sec
E: 0.5,1 MW [0.6,1.5]sec
J: 1,2 MW [0.6,1.5]sec
result: plasma - H-mode
D: ran 1 fault
E: ran
J: ran
next shot: move to USN for phase scan w central deposition
Mar 30 2004 10:42:27:893AM1040330010Steve Wukitch010 USN, 1 MA, BT~5.2 T, nl04~0.85
D: 0.5,1 MW [0.7,1.5]sec
E: 0.5,1 MW [0.7,1.5]sec
J: 2.5 MW ramp [0.8,1.5]sec
result: plasma - H-mode
D: ran max fault
E: ran
J: ran 2 faults
next shot: IWL, lower density to 0.8
Mar 30 2004 10:57:29:363AM1040330011Steve Wukitch011 IWL, 1 MA, BT~5.2 T, nl04~0.8
D: 0.5,1 MW [0.7,1.3]sec
E: 0.5,1 MW [0.7,1.3]sec
J: 2.5 MW ramp [0.8,1.3]sec
result: plasma - H-modes
D: ran 4 faults
E: ran 4 faults
J: ran overload on #3 at L->H
next shot: IWL, less RF power
Mar 30 2004 11:15:34:523AM1040330012Steve Wukitch012 early disruption
Mar 30 2004 11:35:01:187AM1040330013Steve Wukitch013 IWL, 1 MA, BT~5.2 T, nl04~0.8
D: 0.5,1 MW [0.7,1.3]sec
E: -
J: 2.5 MW ramp [0.8,1.3]sec
result: plasma
D: ran
J: ran overload on #3 at late L->H
next shot: lower density to 0.7
Mar 30 2004 11:46:28:137AM1040330014Steve Wukitch014 IWL, 1 MA, BT~5.2 T, nl04~0.8
D: 1 MW [0.7,1.3]sec
E: -
J: 2.5 MW ramp [0.8,1.3]sec
result: plasma
D: ran
J: ran 4 faults
next shot: decrease D antenna to 0.6
Mar 30 2004 11:53:57:770AM1040330015Steve Wukitch015 IWL, 1 MA, BT~5.2 T, nl04~0.8
D: 1 MW [0.7,1.3]sec
E: -
J: 2.5 MW ramp [0.8,1.3]sec
result: plasma
D: ran
J: ran 1 fault
next shot: change phase to +220
Mar 30 2004 12:14:01:873PM1040330016Steve Wukitch016 IWL, 1 MA, BT~5.2 T, nl04~0.8
D: 1 MW [0.7,1.3]sec
E: -
J: 2.5 MW ramp [0.8,1.3]sec, phase is +220
result: plasma
D: ran
J: ran 4 faults
next shot: change phase to +30
Mar 30 2004 12:29:16:453PM1040330017Steve Wukitch017 IWL, 1 MA, BT~5.2 T, nl04~0.8
D: 1 MW [0.7,1.3]sec
E: -
J: 2.5 MW ramp [0.8,1.3]sec, phase is +30 (ctr-current)
result: plasma
D: ran
J: ran 3 faults
next shot: scan BT from 5.2->4.8 T
Mar 30 2004 12:41:46:873PM1040330018Steve Wukitch018 IWL, 1 MA, BT~5.2->4.8 T, nl04~0.8
D: 1 MW [0.7,1.3]sec
E: -
J: 2.5 MW ramp [0.8,1.3]sec, phase is +30 (ctr-current)
result: plasma
D: ran
J: ran max faults
next shot: repeat
Mar 30 2004 12:53:40:883PM1040330019Steve Wukitch019 IWL, 1 MA, BT~5.2->4.8 T, nl04~0.8
D: 1 MW [0.7,1.3]sec
E: -
J: 2.5 MW ramp [0.8,1.3]sec, phase is +30 (ctr-current)
result: plasma
D: ran
J: ran max faults
next shot: repeat with lower RF power
Mar 30 2004 01:25:14:390PM1040330020Steve Wukitch020 IWL, 1 MA, BT~5.2->4.8 T, nl04~0.8
D: 1 MW [0.7,1.3]sec
E: -
J: 2.3 MW ramp [0.8,1.3]sec, phase is +30 (ctr-current)
result: plasma
D: ran
J: ran 4 faults
~1.2 sec sawteeth become longer for two periods (13 msec -> 19 msec)
next shot: repeat
Mar 30 2004 01:25:58:800PM1040330021Steve Wukitch021 IWL, 1 MA, BT~5.2->4.8 T, nl04~0.8
D: 1 MW [0.7,1.3]sec
E: -
J: 2.3 MW ramp [0.8,1.3]sec, phase is +30 (ctr-current)
result: plasma
D: ran
J: ran 4 faults
Again there is a change is ST period around 1.2-1.25 sec
Mar 30 2004 02:07:57:163PM1040330022Steve Wukitch022 IWL, 1 MA, BT~5.2->4.8 T, nl04~0.8
D: 1 MW [0.7,1.3]sec
E: -
J: 2.3 MW ramp [0.8,1.3]sec, phase is +220 (co-current)
result: plasma
D: ran
J: ran 4 faults
Again there is a change is ST period around 1.2-1.25 sec
Mar 30 2004 01:55:19:360PM1040330023Steve Wukitch023 early disruption
Mar 30 2004 02:51:51:930PM1040330024Steve Wukitch024 IWL, 1 MA, BT~5.2->4.8 T, nl04~0.8
D: 1 MW [0.7,1.3]sec
E: -
J: 2.3 MW ramp [0.8,1.3]sec, phase is +130 (heating)
result: plasma
D: ran
J: ran 1 fault
transition in sawtooth period around 1.38 sec - J antenna crossing
earlier transition is associated with D antenna
Mar 30 2004 02:27:14:543PM1040330025Steve Wukitch025 early disruption
Mar 30 2004 02:51:34:333PM1040330026Steve Wukitch026 IWL, 1 MA, BT~5.1->4.9 T, nl04~0.8
D: 1 MW [0.7,1.3]sec
E: -
J: 2.3 MW ramp [0.8,1.3]sec, phase is +130 (heating)
result: plasma - early disruption
D: ran
J: ran

Mar 30 2004 03:04:27:410PM1040330027Steve Wukitch027 NTP
Mar 30 2004 03:26:22:810PM1040330028Steve Wukitch028 IWL, 1 MA, BT~5.1->4.9 T, nl04~0.8
D: 0.6 MW [0.7,1.3]sec
E: -
J: 2.3 MW ramp [0.8,1.3]sec, phase is +130 (heating)
result: plasma
D: ran
J: ran 2 faults
Mar 30 2004 03:49:49:463PM1040330029Steve Wukitch029 IWL, 1 MA, BT~5.1->4.9 T, nl04~0.8
D: 0.6 MW [0.6,1.3]sec
E: -
J: 2.3 MW ramp [0.7,1.3]sec, phase is +130 (heating)
result: plasma
D: ran
J: ran 1 fault
next shot: rampdown and rampup on B-field
Mar 30 2004 04:03:17:520PM1040330030Steve Wukitch030 IWL, 1 MA, BT~5.1->4.9 T, nl04~0.8
D: 0.6 MW [0.6,1.3]sec
E: -
J: 2.3 MW ramp [0.7,1.3]sec, phase is +130 (heating)
result: plasma
D: ran
J: ran 2 faults
next shot: repeat with different antenna phase
Mar 30 2004 04:23:15:607PM1040330031Steve Wukitch031 early disruption
Mar 30 2004 04:23:58:123PM1040330032Steve Wukitch032 IWL, 1 MA, BT~5.1->4.9 T, nl04~0.8
D: 0.6 MW [0.6,1.3]sec
E: -
J: 2.3 MW ramp [0.7,1.3]sec, phase is +220 (co-current)
result: plasma
D: ran
J: ran 4 faults
next shot: repeat with different antenna phase
Mar 30 2004 05:00:17:427PM1040330034Steve Wukitch034 IWL, 1 MA, BT~5.1->4.9 T, nl04~0.8
D: 0.6 MW [0.6,1.3]sec
E: -
J: 2.3 MW ramp [0.7,1.3]sec, phase is +30 (ctr-current)
result: plasma
D: ran
J: ran 3 faults
Mar 30 2004 05:05:50:453PM1040330035Steve Wukitch034 IWL, 1 MA, BT~5.1->4.9 T, nl04~0.8
D: 0.6 MW [0.6,1.3]sec
E: -
J: 2.3 MW ramp [0.7,1.3]sec, phase is +30 (ctr-current)
result: plasma
D: ran
J: ran

Physics Operator Comments
Mar 30 2004 08:07:54:950AMSteve WolfeStart to set up pcs for today's run
Load from 1040309010 (instead of 1040218003) for fiducial
Import seg 2 (USN) of 1040218025 into seg3 (segment3 off)

Load/clean
Filling in configuration /12-NOV-2003 08:00:23.00/
Cleaning PCS tree in /home/wolfe/pcs_scratch
about to ask alcdata to copy /home/wolfe/pcs_scratch/pcs_model to /cmod/trees/models/pcs/pcs_model
Load at 30-Mar-2004 08:07:30.00
Open tree /home/wolfe/pcs_scratch -1
Open tree done
Mar 30 2004 08:18:32:070AMSteve Wolfe
Run plan:

The goal of this mini-proposal is to investigate role of fast particle
pressure and ion cyclotron current drive in modifying the sawtooth
period.

Start with 1040218003 (Fiducial) - 1 MW steps in RF to 4 MW
5.4 T, 1 MA, nl_04~0.8

With square RF pulse, vary J antenna phase for central deposition
(3 shots) [USN (1040218025), BT~5.2 T, Ip ~ 1 MA, nl_04~0.8]

During a discharge, ramp B-field to scan the cyclotron resonance
across the q=1 on both the high field and low field side for co-,
ctr-, and heating phase. (6 shots)

Place minority resonance near the q=1 surface on both the high field
side and low field side for co-, ctr-, and heating phase with 4.5 MW
of ICRF. (6 shots)

Time permitting:

Scan RF power for central deposition in H-mode for co-, ctr-, and
heating (2.5 MW from D and E)

Scan RF power for central deposition in L-mode for co-, ctr-, and
heating (J-port compared to D and E)

At high power scan current with central deposition (0.6, 0.8, 1, 1.2 MA)
Mar 30 2004 08:28:17:893AMSteve WolfeReload after changing title of seg3 to indicate 1MA UN.
Note that Ip on this segment ramps down at 1.3 sec, may need to
extend that when we get to it.

Filling in configuration /12-NOV-2003 08:00:23.00/
Cleaning PCS tree in /home/wolfe/pcs_scratch
about to ask alcdata to copy /home/wolfe/pcs_scratch/pcs_model to /cmod/trees/models/pcs/pcs_model
Load at 30-Mar-2004 08:27:29.00
Open tree /home/wolfe/pcs_scratch -1
Open tree done
Mar 30 2004 09:02:14:340AM1040330004Steve WolfeShot#4:Data system/scanner test
Hung late in store on FRCECE; Gary killed the server and it completed
Mar 30 2004 09:14:47:977AM1040330005Steve WolfeShot#5:First plasma attempt - RF fiducial
plasma full length, got D & E; J had faults.
Two H-modes, high radiation.

next shot: repeat, try for J RF
Mar 30 2004 09:29:27:213AM1040330006Steve WolfeShot#6: repeat, try for J RF
plasma full length, still no J.
3 H-modes this time.

next shot: repeat
Mar 30 2004 09:45:04:590AM1040330007Steve WolfeShot#7: repeat, try for J RF
plasma full length. Still no J, D+E just over 2MW
2 h-modes, still radiating a lot (up to 3.6MW on 2pi foil).
We probably do need to boronize.

next shot: repeat
Mar 30 2004 09:57:10:840AM1040330008Steve WolfeShot#8: repeat, try for J RF
plasma full length, J up to 2MW.
Total RF up to 4.5, some faulting

next shot: repeat and let it clean up
Mar 30 2004 10:13:26:953AM1040330009Steve WolfeShot#9: repeat and let it clean up
plasma full length.

next shot: Begin the MP#380, go to USN
Mar 30 2004 10:33:26:100AM1040330010Steve WolfeShot#10: Begin the MP#380, go to USN in segment 3
**** REPEAT - SEGMENT 3. *******
We'll see how many times I make changes in the wrong place today

Load it up:
Filling in configuration /12-NOV-2003 08:00:23.00/
Cleaning PCS tree in /home/wolfe/pcs_scratch
about to ask alcdata to copy /home/wolfe/pcs_scratch/pcs_model to /cmod/trees/models/pcs/pcs_model
Load at 30-Mar-2004 10:14:11.00
Open tree /home/wolfe/pcs_scratch -1
Open tree done

plasma to 1.66sec; hmode at 1.13sec
there is a funny waveform on EF4
with a step at 1.5

next shot: lower density to .7 and go limited.
Mar 30 2004 10:55:33:830AM1040330011Steve WolfeShot#11: lower density to .7 and go limited.
Import seg2 of 1040218024 into SEG 4!
Raise ip to 1MA, nl4 to .7
remove jump in ic_ef4
Turn 3 off and seg 4 on.

load it:
about to ask alcdata to copy /home/wolfe/pcs_scratch/pcs_model to /cmod/trees/models/pcs/pcs_model
Load at 30-Mar-2004 10:43:46.00
Open tree /home/wolfe/pcs_scratch -1
Open tree done

plasma full length.
Looks like we're still getting short H-modes.

next shot: reduce RF power, trying to stay out of H-mode.
Mar 30 2004 11:15:15:820AM1040330012Steve WolfeShot#12: reduce RF power, trying to stay out of H-mode.
change zxl from -.035 to -.005, rxu from -.02 to 0. (symmetrize)

early disruption: 0.4sec, glitch in current at 0.17sec
looks like a runaway dump

next shot: increase pg4 (seg1) and slow down current rise in seg4
Mar 30 2004 11:24:11:847AM1040330013Steve WolfeShot#13: increase pg4 (seg1) from 15 to 17msec
and slow down current rise in seg4. If this one still disrupts
I'll go back to the funny asym. shape.

plasma full length, no hmode, but it's trying.

next shot: decrease clearin (make it rounder)
Mar 30 2004 11:42:19:570AM1040330014Steve WolfeShot#14: decrease clearin from -.04 to -.05
plasma full length, small glitch at seg switch.
elongation dropped from 1.4 to 1.3
3 tiny hmodes

next shot: increase second seg4 ip point 800->850ka
Mar 30 2004 12:01:37:860PM1040330015Steve WolfeShot#15: increase second seg4 ip point 800->850ka
plasma full length, no hmodes
still a glitch at seg switch? No it's at .07sec
looks like a little runaway dump

next shot: RF will change antenna phase.
Mar 30 2004 12:11:08:963PM1040330016Steve WolfeShot 16: RF changed phase.
plasma full length.
Looks the same to me, but what do I know.

next shot: Increase seg1 pg4 puff to try to kill early runaways
RF changing phase again
Mar 30 2004 12:20:15:067PM1040330017Steve WolfeShot#17: increase seg1 pg4 17->19ms to try to kill off early runaways

plasma full length. still an early glitch, still running out in startup

next shot: scan B down to 4.8, extend current flattop
Mar 30 2004 12:41:23:700PM1040330018Steve WolfeShot#18: increase seg1 pg4 19->21ms to try to kill off early runaways
ramp TF cur from -142->-131ka between 1sec and 1.5sec
extend Ip, nl04, zxu from 1.3 to 1.5

plasma full length, glitches look worse!
Also it loses vertical control at 1.3sec?
Looks like oh2 upper and lower are railing; ps limit is
set for -26. Need to increase at least to -30kA

next shot: increase pg4 from 21 to 24msec; raise oh2 limits to -32kA
Mar 30 2004 12:57:09:727PM1040330019Steve WolfeShot#19: increase pg4 from 21 to 24msec; raise oh2u/l limits to -32kA
plasma full length.
Got rid of the vertical problem, but I still have glitches early;
I think maybe the runaways aren't really the cause.

next shot: minor tweak to zxu early
Mar 30 2004 01:15:42:740PM1040330020Steve WolfeShot#20: minor tweak to zxu early
plasma full length; still got the damned glitch!

next shot: repeat
Mar 30 2004 01:29:52:193PM1040330021Steve WolfeShot#21: repeat; SL says result on 20 was "funny"
plasma to 1.78, disrupts in rampdown
Still has the early glitch

next shot: tweak early seg4 rcur
Mar 30 2004 01:43:37:593PM1040330022Steve WolfeShot#22: tweak early seg4 rcur
plasma to 1.78, glitch is gone.

next shot: flatten rampdown rcur and clearin
Mar 30 2004 02:17:50:003PM1040330024Steve WolfeShot#24: delay zcur3 gain switches (P and D) to .15sec
plasma to 1.75sec, but no early glitch.

next shot: flatten zxu, zxk in rampdown
Change tf ramp
Mar 30 2004 02:36:12:503PM1040330025Steve WolfeShot#24: flatten zxu, zxk in rampdown;
tf ramp [.9,-142kA],[1.0,-139.8],[1.5,-133.8]
i.e. 5.2, 5.1, 4.9T

Another early disruption! Something is causing a big thrash on
efc, ef2L at .1sec, then another at .12; the one at .12 is probably oh crowbar

next shot: Slow down the initial TF rampdown,
Mar 30 2004 02:54:15:690PM1040330026Steve WolfeShot#26: flatten zxu, zxk in rampdown;
tf ramp [.9,-142kA],[1.0,-139.8],[1.5,-133.8]
i.e. 5.2, 5.1, 4.9T
Slow down the initial TF rampdown, at .1sec
One problem is that this PCS program has a clearin referencing the upper
null, with no offset value. This probably is because it evolved from an upper null,
long ago and faraway. I don't think this accounts for the glitch though.

plasma to .65 sec, no early glitch, but it still has the thrash.
Looks like a brick right after rf turnon.
Mar 30 2004 03:05:30:147PM1040330027Steve WolfeShot#27: repeat
fizzle. gas was too high after the disruptions

next shot: Drop pg4 by 3ms
Mar 30 2004 03:23:06:883PM1040330028Steve WolfeShot#28: Drop pg4 by 3ms to 21msec
plasma full length, finally!
Spikes on the h-alpha, no gpc2 this shot.
Ramp is lagging the programming

next shot: revise the tf ramp.
Mar 30 2004 03:37:17:347PM1040330029Steve WolfeShot#29: revise the tf ramp: drop to -139200 at .901 and flat to 1.0,
-132000 at 1.5sec to compensate for finite slew rate

plasma to 1.76sec, long current lag between .2 and .4sec
Got runaways back again.

next shot: pg4 back to 24msec
Mar 30 2004 03:53:17:017PM1040330030Steve WolfeShot#30: pg4 back to 24msec
tf up and down from .8 to 1.15 to 1.5 (142ka to 130ka and back, stepwise)

plasma to 1.76 again.
Ramp rate is faster than I thought, it gets down by 1.05sec, up by 1.4;
SL says leave it.
The glitch is back though. May still have some runaways.

next shot: pg4 to 25msec
Mar 30 2004 04:11:10:147PM1040330031Steve WolfeShot#31: pg4 to 25msec
early disruption, the glitch again!
I have no idea why this is happening

next shot: try again
Mar 30 2004 04:26:53:690PM1040330032Steve WolfeShot#32: try again, no changes
plasma to 1.75sec

next shot: antenna phase change

Mar 30 2004 04:35:49:723PM1040330033Steve WolfeShot#33: antenna phase change

fizzle.

next shot: pg4 to 22msec, br0 up .5mT
Mar 30 2004 04:49:52:657PM1040330034Steve WolfeShot#34:pg4 from 25 to 22msec, br0 from 0 to +.5mT
plasma to 1.7; glitch is there again, bite out of the current
Also runaways.

next shot: 800kA
Mar 30 2004 05:07:24:130PM1040330035Steve WolfeShot#35: Ip to 800kA, pg4 back up to 24msec
plasma full length, with a big bite out of the current around .1 again.
It will have to do. SL says the sawtooth effect is much bigger at this current.

END OF RUN.

Engineering Operator Comments
ShotTimeTypeStatusComment
107:01:14:653AMTestBad
408:50:11:403AMTestOk
509:06:11:407AMPlasmaOk
609:19:31:297AMPlasmaOk
709:35:54:923AMPlasmaOk
809:52:49:397AMPlasmaOk
910:10:17:167AMPlasmaOk
1010:25:33:043AMPlasmaOk
1110:47:10:477AMPlasmaOk
1211:04:19:620AMPlasmaOk
1311:17:16:823AMPlasmaOk
1411:32:05:310AMPlasmaOk
1511:48:22:373AMPlasmaOk
1612:02:44:500PMPlasmaOk
1712:16:46:813PMPlasmaOk
1812:32:02:520PMPlasmaOk
1912:46:45:503PMPlasmaOk
2001:03:50:940PMPlasmaOk
2101:18:42:630PMPlasmaOk
2201:35:53:577PMPlasmaOk
2301:53:15:103PMPlasmaOk
2402:09:39:407PMPlasmaOk
2502:25:08:097PMPlasmaOk
2602:47:10:847PMPlasmaOk
2703:02:14:723PMPlasmaOk
2803:16:02:883PMPlasmaOk
2903:31:22:897PMPlasmaOk
3003:47:47:397PMPlasmaOk
3104:03:23:350PMPlasmaOk
3204:17:32:987PMPlasmaOk
3304:31:17:717PMPlasmaOk
3404:44:21:867PMPlasmaOk
3505:03:19:527PMPlasmaOk
3605:35:58:630PMTestOk
3705:58:22:093PMTestOkscanner test
3807:07:34:430PMTestOkscanner test
3907:27:30:157PMTestOkscanner test