Alcator C-Mod Run 1000607 Information

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Miniproposals
Miniproposal:269
Date Filed: 4/14/2000
Title:ICRF-Induced Plasma Rotation Scaling Studies.
First Author:Paul Bonoli
Session Leader:Paul Bonoli (shots 1-25)

Operators
Session leader(s):Paul Bonoli
Physics operator(s):Ian Hutchinson
Engineering operator(s):Bill Cochran

Engineering Operator Run Comment
MP 269 ICRF Rotation Studies. Bonoli/Hutchinson/Cochran

Session Leader Plans

Physics Operators Plans

Session Leader Summaries
Entered: Jul 7 2004 03:49:24:070PM
Author: To Be Determined
Run Summary for MP 269: ICRF Rotation Studies: 1000607

Physics Operator: Ian Hutchinson
Session Leader: Paul Bonoli

One of the primary objectives of this mini-proposal was to go
to high magnetic field (5.5T -> 6.0T) and measure the toroidal
rotation in the presence of off-axis ICRF D(H) minority heating.
This data was to supplement rotation measurements that had been
made at low toroidal field (4.5T - 5.3T) on May 23, 2000, where
the toroidal rotation was observed to reverse direction from
co- to counter-current. A second objective was to reproduce and
explore in more detail the internal transport barrier (ITB)
formation that had been observed at 4.5 T on 5-23-2000.

The first objective was not accomplished for a variety of reasons.
We had problems with the D-port antenna shutting down due to
voltage arcs, thus we were not able to get sustained H-modes.
We tried raising the current from 0.8 kA to 1.0 MA, increasing the
plasma density, and ramping B_o from 5.3T to 6.0T. All of these
measures did not cure the D-port antenna trips. Finally, we were able
to get both transmitters to stay on by ramping the D-port power from
0.3 MW to about 1.0 MW, with E-port turned on hard (see Shot 014).
Even with both transmitters surviving the entire pulse, good H-modes
could not be achieved because of voltage arcs on the antenna(s) and
subsequent impurity injections. These results were especially frustrating
in that D(H) minority heating was done routinely at (5.5 - 6.6)T during
the 1998 C-Mod run campaign. D and E port antenna operation at high field
should probably be the subject of its own mini-proposal in order to
determine what has changed in the machine since 1998.

The second objective was accomplished with great results (shots 3-8).
We were able to reproduce plasmas with impressive core density barriers
at 4.3 - 4.5 T and with 2.8 MW of off-axis ICRF heating. Central
densities up to 6.0 X 10^20 were measured from visible Bremsstrahlung
with pedestal values around 2 X 10^20 at r/a > 0.5. The core
rotation was also observed to reverse sign. By scanning the toroidal
field in small steps of (5.1, 4.9, 4.7, 4.6, 4.5, 4.3)T, we were able
to establish a critical field of 4.5 T for the onset of the density
barrier mode and the reversal of the toroidal rotation. It is worth
noting that even at 4.6T with the ICRF resonance located 8.4 cm to the
high field side (HFS), the rotation remained co-current for the entire
pulse (see shots 022 and 023). This result would seem to contradict the
theory of Perkins et al., where the rotation is predicted to be counter-
current with an HFS ICRF resonance. The core density barrier mode is also
of special interest because it can be produced in a "steady state"
fashion without continous ramping of the toroidal field. It is
recommended that this low field ITB mode be studied in far more detail
in the future.

Another interesting physics result during this run also came out of the
phase contrast imaging (PCI) diagnostic (see shot 019 for example). The
PCI was able to detect the fast wave as the field was dropped, with
detection occurring first at 4.5T.

A shot by shot description of the run is given below.

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Engineering Setup:

Start ECDC two hours before run.

Power system setup: Same as for 1000602022, except B_t is
programmed to 5.3T flat-top.

Gas Setup: B-Top 6 psi D2 Hybrid enabled
B-side lower 1 psi Argon Hybrid Enabled
C-side 30 psi D2 Hybrid Enabled
J-bottom Leave as is Hybrid DISABLED

RF Setup: RF pulse from 0.7 sec. to 1.4 sec.
D & E antennas to provide 2.2 MW

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1000607001 bonoli SESSION_LEADER Jun 7 2000 9:05:31:186AM
. . . . . . . . . . . . . . . . . . . .
Shot 1: Two OH switches not turned on - try agaon
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1000607002 bonoli SESSION_LEADER Jun 7 2000 9:27:11:110AM
. . . . . . . . . . . . . . . . . . . .
Shot 2: Start B_t scan of rotation - 5.11T
Argon enabled

Plasma - but RF did not stay on (multiple trips on
D & E transmitters).

Take shot again with smaller gap (1 cm)
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1000607003 bonoli SESSION_LEADER Jun 7 2000 9:52:05:856AM
. . . . . . . . . . . . . . . . . . . .
Shot 3: 5.11T - ICRF resonance at 2.1 cm to HFS
Argon enabled
D & E ports retuned (for 5.1 T)

Great Shot !!!!
Plasma - Good EDA H-mode with 108 kJ and nl_04 = 1.5

D & E ran through (with only a few trips) (2.7 - 2.8 MW)
V-tor from HIREXjr is 50 km / s
v-tor from sawtooth precursor about the same

Go on to 4.9 T
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1000607004 bonoli SESSION_LEADER Jun 7 2000 10:03:44:610AM
. . . . . . . . . . . . . . . . . . . .
Shot 4: 4.9T - ICRF resonance at 4.6 cm to HFS
Argon enabled

Another good shot !
Plasma - Good EDA H-mode with 105 kJ and nl_04 = 1.5

D & E antennas stayed on - no trips (2.7 - 2.8 MW)
V-tor from HIREXjr is about 45 km / s
v-tor from sawtooth precursor is higher - about 60 km / s

Go on to 4.7T
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1000607005 bonoli SESSION_LEADER Jun 7 2000 10:25:30:326AM
. . . . . . . . . . . . . . . . . . . .
Shot 5: 4.7T - ICRF resonance at 7.2 cm to HFS
Argon enabled

Another good shot !
Plasma - Good EDA H-mode with 95 kJ and nl_04 = 1.5
H / D ratio about 0.03

D & E antennas stayed on - (2.7 - 2.8 MW)
V-tor from HIREXjr is lower at about 35 km / s
v-tor from sawtooth precursor is even higher - about 55 km / s

Go on to 4.5 T next shot
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1000607006 bonoli SESSION_LEADER Jun 7 2000 10:40:04:450AM
. . . . . . . . . . . . . . . . . . . .
Shot 6: 4.5T - ICRF resonance at 9.7 cm to HFS
Argon enabled

No plasma - fizzle
Try again
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1000607007 bonoli SESSION_LEADER Jun 7 2000 11:06:52:920AM
. . . . . . . . . . . . . . . . . . . .
Shot 7: 4.5T - ICRF resonance at 9.7 cm to HFS
Argon enabled

OBSERVED DENSITY RISE - nl_04 increases to 1.8
Plasma - Goes ELM free(??) with 80-90 kJ
H / D ratio about 0.03

D & E antennas stayed on - (2.7 - 2.8 MW)
V-tor from HIREXjr clearly SLOWING DOWN AND REVERSING SIGN
v-tor from sawtooth precursor also slows down and goes to zero

Take another shot at 4.5T for John Rice to look at poloidal rotation.
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1000607008 bonoli SESSION_LEADER Jun 7 2000 11:29:15:280AM
. . . . . . . . . . . . . . . . . . . .
Shot 8: 4.5T - ICRF resonance at 9.7 cm to HFS
Argon enabled

OBSERVED DENSITY RISE AGAIN- nl_04 increases to 1.8
Plasma - with 80-90 kJ
H / D ratio about 0.03

D & E antennas stayed on - (2.7 MW)
V-tor from HIREXjr clearly SLOWING DOWN AND REVERSING SIGN to about -30 km / s
v-tor from sawtooth precursor also slows down and goes to zero

Next shot at 5.5T
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1000607009 bonoli SESSION_LEADER Jun 7 2000 11:42:26:746AM
. . . . . . . . . . . . . . . . . . . .
Shot 9: 5.5T - ICRF resonance at 3 cm to the LFS
Argon enabled

Plasma - EDA H-mode with with 108 kJ and nl_04 = 1.5
H / D ratio about 0.03

D & E antennas - suffered from multiple trips (2.7 - 2.8 MW) maximum.
V-tor from HIREXjr about 40 km / s, but not very long duration

Take another shot at 5.5T
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1000607010 bonoli SESSION_LEADER Jun 7 2000 11:57:25:013AM
. . . . . . . . . . . . . . . . . . . .
Shot 10: 5.5T - ICRF resonance at 3 cm to the LFS
Argon enabled

Plasma - EDA H-mode with with 102 kJ with nl_04 = 1.5
H / D ratio about 0.03

ICRF power 2.7 MW
E-antenna ran flawlessly
D-port has some trips

V-tor from HIREXjr about 40 km / s, with good duration

Next shot at 5.75 T
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1000607011 bonoli SESSION_LEADER Jun 7 2000 12:24:35:920PM
. . . . . . . . . . . . . . . . . . . .
Shot 11: 5.75T - ICRF resonance at 6.2 cm to the LFS
Argon enabled

Plasma - Short H-mode
H / D ratio about 0.03

ICRF power 2.7 MW
E-antenna ran flawlessly
D-port shit down at 0.92 sec.

Try raising current to 1.0 MA on next shot to get same
q (safety factor) that we had at 4.5 T. Maybe D-antenna
will do better.
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1000607012 bonoli SESSION_LEADER Jun 7 2000 12:46:47:983PM
. . . . . . . . . . . . . . . . . . . .
Shot 12: 5.75T - ICRF resonance at 6.2 cm to the LFS
I_p = 1.0 MA
Argon enabled

D - antenna shut down - just like at 800 kA
E-antenna survives with multiple trips

Got an H-mode, not very long duration - not enough for a good V-tor
measurement from HIREXjr

Plan for next shot:
Go back to 800 kA
Run D-antenna at maxumum power
Start E-antenna at 500 kW and ramp up power during pulse.
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1000607013 bonoli SESSION_LEADER Jun 7 2000 1:09:13:733PM
. . . . . . . . . . . . . . . . . . . .
Shot 13: 5.75T - ICRF resonance at 6.2 cm to the LFS
I_p = 0.8 MA and E-antenna power ramped from 500 kW
Argon enabled

D - antenna shut down again
E-antenna ramped up nicely from 0.5 MW

Got an H-mode, EDA-like. H-mode energy about 80 kJ.

Plan for next shot:
Stay at 800 kA
Ramp up D-antenna from 300 kW
Run E-antenna near maximum power for entire pulse.
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1000607014 bonoli SESSION_LEADER Jun 7 2000 1:34:32:403PM
. . . . . . . . . . . . . . . . . . . .
Shot 14: 5.75T - ICRF resonance at 6.2 cm to the LFS
I_p = 0.8 MA and D-antenna power ramped from 300 kW
Argon enabled

D & E survived the pulse operting in this mode.

Got multiple H-modes with 80 kJ of stored energy. But still had
big impurity injections.

Plan for next shot:
Stay at 800 kA
Ramp up D-antenna from 300 kW with slight retunr.
Run E-antenna near maximum power for entire pulse
with turn on time increased to 30 msec.
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1000607015 bonoli SESSION_LEADER Jun 7 2000 1:44:59:890PM
. . . . . . . . . . . . . . . . . . . .
Shot 15: 5.75T - ICRF resonance at 6.2 cm to the LFS
I_p = 0.8 MA
D-antenna power ramped from 300 kW
E-port turn on longer (30 msec)
Argon enabled

D & E operated without trips to point of plasma disruption at 0.83 sec.
caused by an impurity injection from antenna.


Plan for next shot:
Go to 6.0 T
Use same waveforms for D & E powers.

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1000607016 bonoli SESSION_LEADER Jun 7 2000 2:11:39:310PM
. . . . . . . . . . . . . . . . . . . .
Shot 16: 6.0T - ICRF resonance at 9.4 cm to the LFS
I_p = 0.8 MA
D-antenna power ramped from 300 kW
E-antenna turn on longer (30 msec)
Argon enabled

D & E had multiple trips with INCREDIBLE MULTIPLE FIREWORKS ! and injections

Plan for next shot:
BACK OFF ON D & E -antenna powers, using same turn - on waveforms

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1000607017 bonoli SESSION_LEADER Jun 7 2000 2:32:17:406PM
. . . . . . . . . . . . . . . . . . . .
Shot 17: 6.0T - ICRF resonance at 9.4 cm to the LFS
I_p = 0.8 MA
D-antenna power ramped from 300 kW to 1.0 MW (max.)
E-antenna power limited to 1.0 MW (max.)
Argon enabled

D & E antennas ran with minimal trips - but lots of injections caused
by antenna arcs.

Plan for next shot:
Keep rf power lowered to 2 MW max.
Ramp B_t from 5.3T to 6.0T and get rf to "catch - on" at
lower field.

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1000607018 bonoli SESSION_LEADER Jun 7 2000 3:01:42:716PM
. . . . . . . . . . . . . . . . . . . .
Shot 18: Ramp B_t from 5.3T to 6.0T.
D-antenna power ramped from 300 kW to 1.0 MW (max.)
E-antenna power limited to 1.0 MW (max.)
Argon enabled

Got multiple H-modes accompanied by rf trips, although D & E port
did survive the entire pulse.

Plan for next shot:

Go back down in field to 4.3T to fill in data points.
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1000607019 bonoli SESSION_LEADER Jun 7 2000 3:35:34:796PM
. . . . . . . . . . . . . . . . . . . .
Shot 19: 4.3T - ICRF resonance is 12.3 cm to HFS
D & E antennas at 2.8 MW (max.)
Argon enabled

D & E ran ok with about 2.8 MW
Multiple arcs on E-port antenna accompanied by impurity injections.

Plasma - three multiple H-modes and then density barrier forms
with nl_04 = 1.73.
HIREXjr shows V-tor slowing down and reversing sign again.
PCI detecting fast wave.

Plan for next shot:
Stay at 4.3T and back off on E-port power to 1.0 MW
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1000607020 bonoli SESSION_LEADER Jun 7 2000 3:34:14:840PM
. . . . . . . . . . . . . . . . . . . .
Shot 20: 4.3T - ICRF resonance is 12.3 cm to HFS
E-antenna at lower power to eliminate arcs.
Argon enabled

D & E ran ok with about 2.5 MW (arcing almost gone on antenna)

Plasma - Got density barrier again with multiple H-mode transitions
superposed on barrier formation.
V-tor from HIREXjr agian shows sign reversal (more clearly than Shot 19).

Take one more shot at 4.3T for PCI to block signal and confirm fast
wave detection.

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1000607021 bonoli SESSION_LEADER Jun 7 2000 3:51:55:340PM
. . . . . . . . . . . . . . . . . . . .
Shot 21: 4.3T - ICRF resonance is 12.3 cm to HFS
E-antenna at lower power to eliminate arcs.
Argon enabled

D & E ran and survived, although some arcing was observed on cameras.

Plasma - Got density peaking again with multiple H-mode transitions
superposed on barrier formation.
V-tor from HIREXjr again shows sign reversal.

Next shot go to 4.6T.

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1000607022 bonoli SESSION_LEADER Jun 7 2000 4:37:18:013PM
. . . . . . . . . . . . . . . . . . . .
Shot 22: 4.6T - ICRF resonance is 8.4 cm to HFS
Fill in data bewteen 4.5T and 4.7
Entered: Jul 7 2004 03:49:24:100PM
Author: To Be Determined

Argon enaboled.

ICRf power at 2.4 MW (max.)
D - antenna had some trips but survived.
E - antenna ran fine

Plasma - No density peaking but got multiple H-mode transitions
following voltage arcs on antenna and impurity injections.

Plasma rotation co-current (HIREXjr)

Next shot - try reducing plasma-antenna gap from 1.5 cm to 1.0 cm
to reduce voltage on antenna
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1000607023 bonoli SESSION_LEADER Jun 7 2000 4:34:10:360PM
. . . . . . . . . . . . . . . . . . . .
Shot 23: 4.6T - ICRF resonance is 8.4 cm to HFS
Reduce plasma-antenna gap from 1.5 cm to 1.0 cm
Argon enabled.

D - antenna shut down at 0.88 sec.
E - antenna ran fine

Plasma - No density peaking but got multiple H-mode transitions again
following voltage arcs on antenna and impurity injections.

Plasma rotation remains co-current (from HIREXjr)

Got to 4.1T next shot
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1000607024 bonoli SESSION_LEADER Jun 7 2000 4:52:20:466PM
. . . . . . . . . . . . . . . . . . . .
Shot 24: 4.1T - ICRF resonance is 14.8 cm to HFS
Add ramp to D-port (again) to try to avoid arcing.
E-port at max. power
Argon enabled.

D & E ran fine - no trips....but

Plasma - Got five H-mode transitions with nl_04 rise to 1.5
No density barrier observed.
Plasma rotation very small.

Reload 4.5T (shot 8) for last shot of the day.

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1000607025 bonoli SESSION_LEADER Jun 7 2000 5:06:59:186PM
. . . . . . . . . . . . . . . . . . . .
Shot 25: 4.5T - try repeating Shot 8 (ICRF resonance at 9.4 cm to HFS)
Add ramp to D-port (again) to try to avoid arcing.
E-port at max. power
Argon enabled.

D & E ran with multiple trips throughout

Plasma - Got three H-mode transitions with nl_04 rise to 1.5
Multiple injections. No density barrier observed.

Plasma rotation again very small.


Physics Operator Summaries
Entered: Jul 7 2004 04:37:11:113PM
Author: To Be Determined
Physop 1000607 MP269 ICRF Resonance Scan

SL Bonoli
PO Hutch

Summary
_______

The internal barrier mode was obtained for fields below 4.6T
reproducibly. And the rotation reproducibly ramped down. Some
additional points were filled in on the scan. It proved impossible to
get good ICRF heating at fields above 5.5T, which was the main point
of the run, because of arcs on the E-port antenna that did not trip it
out but brought in much impurity. Thus, there is a very sensitive
dependence of RF antenna arcing on the field.

The status of the original test of theory remains unchanged from last
week. Initial rotation in H-mode is strongly co-current right down to
the lowest field explored. But the waters are muddied by the density
peaking and simultaneous spin down and slight reversal that occurs
progressively at low field.



Scorecard
_________

Shot,Duration(s),Ipmax(MA) Shot,Duration(s),Ipmax
1 0.000 0.014 2 1.894 0.804
3 1.903 0.801 4 1.898 0.806
5 1.911 0.803 6 0.000 0.042
7 1.896 0.800 8 1.893 0.800
9 1.900 0.805 10 1.889 0.808
11 1.265 0.806 12 1.914 0.998
13 1.879 0.803 14 1.328 0.819
15 0.841 0.829 16 1.896 0.799
17 1.871 0.802 18 1.895 0.802
19 1.471 0.797 20 1.487 0.799
21 1.659 0.799 22 1.913 0.800
23 1.895 0.795 24 1.862 0.797
25 1.925 0.794
Finished summary for 1000607 Total of 25 shots.
25 shots. 23 plasmas. 1 fizzles. 1 duds.
Dud was a power supply mistake.

Details
_______

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1000607xxx hutch PHYSICS_OPERATOR Jun 7 2000 8:53:05:340AM
. . . . . . . . . . . . . . . . . . . .
MP269 Off-axis ICRF resonance.

Cold Start
Import Segment 2 from 1000602022
Set ITF to 142kA.
Load.
Set TF final zero point to 3s to comply with the Wolfe request to limit
slew rate.
Load.
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1000607001 hutch PHYSICS_OPERATOR Jun 7 2000 9:04:51:966AM
. . . . . . . . . . . . . . . . . . . .
Dud due to power supplies.

OH2s screwed up. It looks as if the upper switch did not close. It never
reaches current. Operator error on setup. The OH2 switches were not set
properly.
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1000607002 hutch PHYSICS_OPERATOR Jun 7 2000 9:45:11:860AM
. . . . . . . . . . . . . . . . . . . .
Reduce fill puff to 19ms, to compensate for the DNB being on.

Plasma. Short H-mode with substantial radiation. RF trips repeatedly.

Move RCUR out to .68-9 to lower the outer gap
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1000607003 hutch PHYSICS_OPERATOR Jun 7 2000 9:56:30:390AM
. . . . . . . . . . . . . . . . . . . .
Plasma. RF stays on at 2.75MW! Rotates at about 50km/s

I_TF to 136kA, 4.9T.
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1000607004 hutch PHYSICS_OPERATOR Jun 7 2000 10:18:03:420AM
. . . . . . . . . . . . . . . . . . . .
Plasma. RF stays on. Good sawteeth fast rotation.

I_TF to 130kA.
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1000607005 hutch PHYSICS_OPERATOR Jun 7 2000 10:39:01:450AM
. . . . . . . . . . . . . . . . . . . .
Plasma. RF stays on. 13kHz sawteeth.

I_Tf to 124kA. 4.5T
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1000607006 hutch PHYSICS_OPERATOR Jun 7 2000 10:49:41:403AM
. . . . . . . . . . . . . . . . . . . .
Fizzle

ICEF4 to -1270A from -1280
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1000607007 hutch PHYSICS_OPERATOR Jun 7 2000 11:14:10:640AM
. . . . . . . . . . . . . . . . . . . .
Plasma. RF stays on. Density rises, very peaked on axis.
Plasma rotation slows to zero in about 250ms.
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1000607008 hutch PHYSICS_OPERATOR Jun 7 2000 11:31:52:780AM
. . . . . . . . . . . . . . . . . . . .
Plasma. Similar to 7.

I_TF to 154kA. 5.5T.
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1000607009 hutch PHYSICS_OPERATOR Jun 7 2000 11:51:40:263AM
. . . . . . . . . . . . . . . . . . . .
Plasma. RF trips at 1.1s

Repeat.
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1000607010 hutch PHYSICS_OPERATOR Jun 7 2000 12:14:42:436PM
. . . . . . . . . . . . . . . . . . . .
Plasma. Very similar.

I_Tf to 162kA.
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1000607011 hutch PHYSICS_OPERATOR Jun 7 2000 12:33:07:343PM
. . . . . . . . . . . . . . . . . . . .
Plasma disrupts at 1.25s. RF trips with big impurity injections.
The fast camera shows a lot of plasma-antenna interaction at the top.

Raise current to 1MA.
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1000607012 hutch PHYSICS_OPERATOR Jun 7 2000 12:55:32:326PM
. . . . . . . . . . . . . . . . . . . .
Plasma. RF trips.

Ip back to .8MA
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1000607013 hutch PHYSICS_OPERATOR Jun 7 2000 1:15:20:903PM
. . . . . . . . . . . . . . . . . . . .
Plasma. Hmode to 1.3s. RF trips at 1s but enough power from E to sustain.

ICEF4 to -1280A from -1270.
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1000607014 hutch PHYSICS_OPERATOR Jun 7 2000 1:37:00:076PM
. . . . . . . . . . . . . . . . . . . .
Did not load since 12.45 so the previous initiation tweak not here till 15.

Plasma disrupts at 1.3s. RF stays on but with many arcs bringing in
impurities.
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1000607015 hutch PHYSICS_OPERATOR Jun 7 2000 1:58:59:156PM
. . . . . . . . . . . . . . . . . . . .
Disrupts at .83s. Giant injections.

Fill puff to 18ms.
I_TF to 170kA (6T).
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1000607016 hutch PHYSICS_OPERATOR Jun 7 2000 2:21:42:810PM
. . . . . . . . . . . . . . . . . . . .
Plasma. Many injections, but RF stayed on. Camera shows lots of antenna arcs.
A spectacular shot on the antenna.

Ask for lower RF power.
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1000607017 hutch PHYSICS_OPERATOR Jun 7 2000 2:45:28:076PM
. . . . . . . . . . . . . . . . . . . .
Plasma.

Install a field ramp up from 5.3T during the RF.
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1000607018 hutch PHYSICS_OPERATOR Jun 7 2000 3:08:42:936PM
. . . . . . . . . . . . . . . . . . . .
Plasma. Starts well but deteriorates as the field moves up. Antenna arcs.

Import segment 2 from shot 7
I_TF to 118kA 4.3T
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1000607019 hutch PHYSICS_OPERATOR Jun 7 2000 3:29:39:326PM
. . . . . . . . . . . . . . . . . . . .
Plasma. Got the E-port arc even at this low field.
A density peaking at the end leads to disruption at 1.45s

Take 1ms off the fill puff.
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1000607020 hutch PHYSICS_OPERATOR Jun 7 2000 3:45:08:030PM
. . . . . . . . . . . . . . . . . . . .
Plasma. Barrier leads to disruption. Not such obvious antenna arcs, but
radiation climbs to 2MW quickly during H-modes.

No changes. A shot for the PCI.
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1000607021 hutch PHYSICS_OPERATOR Jun 7 2000 4:03:07:013PM
. . . . . . . . . . . . . . . . . . . .
Plasma. Similar to previous. Some momentary arcs present on antenna ?D?

I_TF to 127kA. 4.6T
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1000607022 hutch PHYSICS_OPERATOR Jun 7 2000 4:19:09:293PM
. . . . . . . . . . . . . . . . . . . .
Plasma. No density peaking. Repetitive reversions to L-mode. Radiation is
significantly worse than earlier in the run. RF does not stay on well.

RCUR to .67 reducing the outer gap by 3-4mm.
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1000607023 hutch PHYSICS_OPERATOR Jun 7 2000 4:40:11:060PM
. . . . . . . . . . . . . . . . . . . .
Plasma. Only 1MW RF because of trips.

I_TF to 112kA, 4.1T
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1000607024 hutch PHYSICS_OPERATOR Jun 7 2000 4:57:59:093PM
. . . . . . . . . . . . . . . . . . . .
Plasma. Five accumulating H-modes.

Add 1ms of fill puff.
I_TF 124kA, 4.5T. NL04 to .8e20 from .9
----------------------------------------------------------------------------
1000607024 hutch PHYSICS_OPERATOR Jun 7 2000 5:11:19:390PM
. . . . . . . . . . . . . . . . . . . .
Plasma. ICRF trips out.


Session Leader Comments
Jun 7 2000 09:05:31:187AM1000607001Paul BonoliShot 1: Two OH switches not turned on - try agaon
Jun 7 2000 09:27:11:110AM1000607002Paul BonoliShot 2: Start B_t scan of rotation - 5.11T
Argon enabled

Plasma - but RF did not stay on (multiple trips on
D & E transmitters).

Take shot again with smaller gap (1 cm)
Jun 7 2000 09:52:05:857AM1000607003Paul BonoliShot 3: 5.11T - ICRF resonance at 2.1 cm to HFS
Argon enabled
D & E ports retuned (for 5.1 T)

Great Shot !!!!
Plasma - Good EDA H-mode with 108 kJ and nl_04 = 1.5

D & E ran through (with only a few trips) (2.7 - 2.8 MW)
V-tor from HIREXjr is 50 km / s
v-tor from sawtooth precursor about the same

Go on to 4.9 T
Jun 7 2000 10:03:44:610AM1000607004Paul BonoliShot 4: 4.9T - ICRF resonance at 4.6 cm to HFS
Argon enabled

Another good shot !
Plasma - Good EDA H-mode with 105 kJ and nl_04 = 1.5

D & E antennas stayed on - no trips (2.7 - 2.8 MW)
V-tor from HIREXjr is about 45 km / s
v-tor from sawtooth precursor is higher - about 60 km / s

Go on to 4.7T
Jun 7 2000 10:25:30:327AM1000607005Paul BonoliShot 5: 4.7T - ICRF resonance at 7.2 cm to HFS
Argon enabled

Another good shot !
Plasma - Good EDA H-mode with 95 kJ and nl_04 = 1.5
H / D ratio about 0.03

D & E antennas stayed on - (2.7 - 2.8 MW)
V-tor from HIREXjr is lower at about 35 km / s
v-tor from sawtooth precursor is even higher - about 55 km / s

Go on to 4.5 T next shot
Jun 7 2000 10:40:04:450AM1000607006Paul BonoliShot 6: 4.5T - ICRF resonance at 9.7 cm to HFS
Argon enabled

No plasma - fizzle
Try again
Jun 7 2000 11:06:52:920AM1000607007Paul BonoliShot 7: 4.5T - ICRF resonance at 9.7 cm to HFS
Argon enabled

OBSERVED DENSITY RISE - nl_04 increases to 1.8
Plasma - Goes ELM free(??) with 80-90 kJ
H / D ratio about 0.03

D & E antennas stayed on - (2.7 - 2.8 MW)
V-tor from HIREXjr clearly SLOWING DOWN AND REVERSING SIGN
v-tor from sawtooth precursor also slows down and goes to zero

Take another shot at 4.5T for John Rice to look at poloidal rotation.
Jun 7 2000 11:29:15:280AM1000607008Paul BonoliShot 8: 4.5T - ICRF resonance at 9.7 cm to HFS
Argon enabled

OBSERVED DENSITY RISE AGAIN- nl_04 increases to 1.8
Plasma - with 80-90 kJ
H / D ratio about 0.03

D & E antennas stayed on - (2.7 MW)
V-tor from HIREXjr clearly SLOWING DOWN AND REVERSING SIGN to about -30 km / s
v-tor from sawtooth precursor also slows down and goes to zero

Next shot at 5.5T
Jun 7 2000 11:42:26:747AM1000607009Paul BonoliShot 9: 5.5T - ICRF resonance at 3 cm to the LFS
Argon enabled

Plasma - EDA H-mode with with 108 kJ and nl_04 = 1.5
H / D ratio about 0.03

D & E antennas - suffered from multiple trips (2.7 - 2.8 MW) maximum.
V-tor from HIREXjr about 40 km / s, but not very long duration

Take another shot at 5.5T
Jun 7 2000 11:57:25:013AM1000607010Paul BonoliShot 10: 5.5T - ICRF resonance at 3 cm to the LFS
Argon enabled

Plasma - EDA H-mode with with 102 kJ with nl_04 = 1.5
H / D ratio about 0.03

ICRF power 2.7 MW
E-antenna ran flawlessly
D-port has some trips

V-tor from HIREXjr about 40 km / s, with good duration

Next shot at 5.75 T
Jun 7 2000 12:24:35:920PM1000607011Paul BonoliShot 11: 5.75T - ICRF resonance at 6.2 cm to the LFS
Argon enabled

Plasma - Short H-mode
H / D ratio about 0.03

ICRF power 2.7 MW
E-antenna ran flawlessly
D-port shit down at 0.92 sec.

Try raising current to 1.0 MA on next shot to get same
q (safety factor) that we had at 4.5 T. Maybe D-antenna
will do better.
Jun 7 2000 12:46:47:983PM1000607012Paul BonoliShot 12: 5.75T - ICRF resonance at 6.2 cm to the LFS
I_p = 1.0 MA
Argon enabled

D - antenna shut down - just like at 800 kA
E-antenna survives with multiple trips

Got an H-mode, not very long duration - not enough for a good V-tor
measurement from HIREXjr

Plan for next shot:
Go back to 800 kA
Run D-antenna at maxumum power
Start E-antenna at 500 kW and ramp up power during pulse.

Jun 7 2000 01:09:13:733PM1000607013Paul BonoliShot 13: 5.75T - ICRF resonance at 6.2 cm to the LFS
I_p = 0.8 MA and E-antenna power ramped from 500 kW
Argon enabled

D - antenna shut down again
E-antenna ramped up nicely from 0.5 MW

Got an H-mode, EDA-like. H-mode energy about 80 kJ.

Plan for next shot:
Stay at 800 kA
Ramp up D-antenna from 300 kW
Run E-antenna near maximum power for entire pulse.

Jun 7 2000 01:34:32:403PM1000607014Paul BonoliShot 14: 5.75T - ICRF resonance at 6.2 cm to the LFS
I_p = 0.8 MA and D-antenna power ramped from 300 kW
Argon enabled

D & E survived the pulse operting in this mode.

Got multiple H-modes with 80 kJ of stored energy. But still had
big impurity injections.

Plan for next shot:
Stay at 800 kA
Ramp up D-antenna from 300 kW with slight retunr.
Run E-antenna near maximum power for entire pulse
with turn on time increased to 30 msec.

Jun 7 2000 01:44:59:890PM1000607015Paul BonoliShot 15: 5.75T - ICRF resonance at 6.2 cm to the LFS
I_p = 0.8 MA
D-antenna power ramped from 300 kW
E-port turn on longer (30 msec)
Argon enabled

D & E operated without trips to point of plasma disruption at 0.83 sec.
caused by an impurity injection from antenna.


Plan for next shot:
Go to 6.0 T
Use same waveforms for D & E powers.
Jun 7 2000 02:11:39:310PM1000607016Paul BonoliShot 16: 6.0T - ICRF resonance at 9.4 cm to the LFS
I_p = 0.8 MA
D-antenna power ramped from 300 kW
E-antenna turn on longer (30 msec)
Argon enabled

D & E had multiple trips with INCREDIBLE MULTIPLE FIREWORKS ! and injections

Plan for next shot:
BACK OFF ON D & E -antenna powers, using same turn - on waveforms
Jun 7 2000 02:32:17:407PM1000607017Paul BonoliShot 17: 6.0T - ICRF resonance at 9.4 cm to the LFS
I_p = 0.8 MA
D-antenna power ramped from 300 kW to 1.0 MW (max.)
E-antenna power limited to 1.0 MW (max.)
Argon enabled

D & E antennas ran with minimal trips - but lots of injections caused
by antenna arcs.

Plan for next shot:
Keep rf power lowered to 2 MW max.
Ramp B_t from 5.3T to 6.0T and get rf to "catch - on" at
lower field.
Jun 7 2000 03:01:42:717PM1000607018Paul BonoliShot 18: Ramp B_t from 5.3T to 6.0T.
D-antenna power ramped from 300 kW to 1.0 MW (max.)
E-antenna power limited to 1.0 MW (max.)
Argon enabled

Got multiple H-modes accompanied by rf trips, although D & E port
did survive the entire pulse.

Plan for next shot:

Go back down in field to 4.3T to fill in data points.

Jun 7 2000 03:35:34:797PM1000607019Paul BonoliShot 19: 4.3T - ICRF resonance is 12.3 cm to HFS
D & E antennas at 2.8 MW (max.)
Argon enabled

D & E ran ok with about 2.8 MW
Multiple arcs on E-port antenna accompanied by impurity injections.

Plasma - three multiple H-modes and then density barrier forms
with nl_04 = 1.73.
HIREXjr shows V-tor slowing down and reversing sign again.
PCI detecting fast wave.

Plan for next shot:
Stay at 4.3T and back off on E-port power to 1.0 MW
Jun 7 2000 03:34:14:840PM1000607020Paul BonoliShot 20: 4.3T - ICRF resonance is 12.3 cm to HFS
E-antenna at lower power to eliminate arcs.
Argon enabled

D & E ran ok with about 2.5 MW (arcing almost gone on antenna)

Plasma - Got density barrier again with multiple H-mode transitions
superposed on barrier formation.
V-tor from HIREXjr agian shows sign reversal (more clearly than Shot 19).

Take one more shot at 4.3T for PCI to block signal and confirm fast
wave detection.
Jun 7 2000 03:51:55:340PM1000607021Paul BonoliShot 21: 4.3T - ICRF resonance is 12.3 cm to HFS
E-antenna at lower power to eliminate arcs.
Argon enabled

D & E ran and survived, although some arcing was observed on cameras.

Plasma - Got density peaking again with multiple H-mode transitions
superposed on barrier formation.
V-tor from HIREXjr again shows sign reversal.

Next shot go to 4.6T.
Jun 7 2000 04:37:18:013PM1000607022Paul BonoliShot 22: 4.6T - ICRF resonance is 8.4 cm to HFS
Fill in data bewteen 4.5T and 4.7T
Argon enaboled.

ICRf power at 2.4 MW (max.)
D - antenna had some trips but survived.
E - antenna ran fine

Plasma - No density peaking but got multiple H-mode transitions
following voltage arcs on antenna and impurity injections.

Plasma rotation co-current (HIREXjr)

Next shot - try reducing plasma-antenna gap from 1.5 cm to 1.0 cm
to reduce voltage on antenna
Jun 7 2000 04:34:10:360PM1000607023Paul BonoliShot 23: 4.6T - ICRF resonance is 8.4 cm to HFS
Reduce plasma-antenna gap from 1.5 cm to 1.0 cm
Argon enabled.

D - antenna shut down at 0.88 sec.
E - antenna ran fine

Plasma - No density peaking but got multiple H-mode transitions again
following voltage arcs on antenna and impurity injections.

Plasma rotation remains co-current (from HIREXjr)

Got to 4.1T next shot
Jun 7 2000 04:52:20:467PM1000607024Paul BonoliShot 24: 4.1T - ICRF resonance is 14.8 cm to HFS
Add ramp to D-port (again) to try to avoid arcing.
E-port at max. power
Argon enabled.

D & E ran fine - no trips....but

Plasma - Got five H-mode transitions with nl_04 rise to 1.5
No density barrier observed.
Plasma rotation very small.

Reload 4.5T (shot 8) for last shot of the day.

Jun 7 2000 05:06:59:187PM1000607025Paul BonoliShot 25: 4.5T - try repeating Shot 8 (ICRF resonance at 9.4 cm to HFS)
Add ramp to D-port (again) to try to avoid arcing.
E-port at max. power
Argon enabled.

D & E ran with multiple trips throughout

Plasma - Got three H-mode transitions with nl_04 rise to 1.5
Multiple injections. No density barrier observed.

Plasma rotation again very small.

Physics Operator Comments
Jun 7 2000 08:53:05:340AMIan HutchinsonMP269 Off-axis ICRF resonance.

Cold Start
Import Segment 2 from 1000602022
Set ITF to 142kA.
Load.
Set TF final zero point to 3s to comply with the Wolfe request to limit
slew rate.
Load.
Jun 7 2000 09:04:51:967AM1000607001Ian HutchinsonDud due to power supplies.

OH2s screwed up. It looks as if the upper switch did not close. It never
reaches current. Operator error on setup. The OH2 switches were not set
properly.
Jun 7 2000 09:45:11:860AM1000607002Ian HutchinsonReduce fill puff to 19ms, to compensate for the DNB being on.

Plasma. Short H-mode with substantial radiation. RF trips repeatedly.

Move RCUR out to .68-9 to lower the outer gap
Jun 7 2000 09:56:30:390AM1000607003Ian HutchinsonPlasma. RF stays on at 2.75MW! Rotates at about 50km/s

I_TF to 136kA, 4.9T.
Jun 7 2000 10:18:03:420AM1000607004Ian HutchinsonPlasma. RF stays on. Good sawteeth fast rotation.

I_TF to 130kA.
Jun 7 2000 10:39:01:450AM1000607005Ian HutchinsonPlasma. RF stays on. 13kHz sawteeth.

I_Tf to 124kA. 4.5T
Jun 7 2000 10:49:41:403AM1000607006Ian HutchinsonFizzle

ICEF4 to -1270A from -1280
Jun 7 2000 11:14:10:640AM1000607007Ian HutchinsonPlasma. RF stays on. Density rises, very peaked on axis.
Plasma rotation slows to zero in about 250ms.
Jun 7 2000 11:31:52:780AM1000607008Ian HutchinsonPlasma. Similar to 7.

I_TF to 154kA. 5.5T.
Jun 7 2000 11:51:40:263AM1000607009Ian HutchinsonPlasma. RF trips at 1.1s

Repeat.
Jun 7 2000 12:14:42:437PM1000607010Ian HutchinsonPlasma. Very similar.

I_Tf to 162kA.
Jun 7 2000 12:33:07:343PM1000607011Ian HutchinsonPlasma disrupts at 1.25s. RF trips with big impurity injections.
The fast camera shows a lot of plasma-antenna interaction at the top.

Raise current to 1MA.
Jun 7 2000 12:55:32:327PM1000607012Ian HutchinsonPlasma. RF trips.

Ip back to .8MA
Jun 7 2000 01:15:20:903PM1000607013Ian HutchinsonPlasma. Hmode to 1.3s. RF trips at 1s but enough power from E to sustain.

ICEF4 to -1280A from -1270.
Jun 7 2000 01:37:00:077PM1000607014Ian HutchinsonDid not load since 12.45 so the previous initiation tweak not here till 15.

Plasma disrupts at 1.3s. RF stays on but with many arcs bringing in
impurities.
Jun 7 2000 01:58:59:157PM1000607015Ian HutchinsonDisrupts at .83s. Giant injections.

Fill puff to 18ms.
I_TF to 170kA (6T).
Jun 7 2000 02:21:42:810PM1000607016Ian HutchinsonPlasma. Many injections, but RF stayed on. Camera shows lots of antenna arcs.
A spectacular shot on the antenna.

Ask for lower RF power.
Jun 7 2000 02:45:28:077PM1000607017Ian HutchinsonPlasma.

Install a field ramp up from 5.3T during the RF.
Jun 7 2000 03:08:42:937PM1000607018Ian HutchinsonPlasma. Starts well but deteriorates as the field moves up. Antenna arcs.

Import segment 2 from shot 7
I_TF to 118kA 4.3T
Jun 7 2000 03:29:39:327PM1000607019Ian HutchinsonPlasma. Got the E-port arc even at this low field.
A density peaking at the end leads to disruption at 1.45s

Take 1ms off the fill puff.
Jun 7 2000 03:45:08:030PM1000607020Ian HutchinsonPlasma. Barrier leads to disruption. Not such obvious antenna arcs, but
radiation climbs to 2MW quickly during H-modes.

No changes. A shot for the PCI.
Jun 7 2000 04:03:07:013PM1000607021Ian HutchinsonPlasma. Similar to previous. Some momentary arcs present on antenna ?D?

I_TF to 127kA. 4.6T
Jun 7 2000 04:19:09:293PM1000607022Ian HutchinsonPlasma. No density peaking. Repetitive reversions to L-mode. Radiation is
significantly worse than earlier in the run. RF does not stay on well.

RCUR to .67 reducing the outer gap by 3-4mm.
Jun 7 2000 04:40:11:060PM1000607023Ian HutchinsonPlasma. Only 1MW RF because of trips.

I_TF to 112kA, 4.1T
Jun 7 2000 04:57:59:093PM1000607024Ian HutchinsonPlasma. Five accumulating H-modes.

Add 1ms of fill puff.
I_TF 124kA, 4.5T. NL04 to .8e20 from .9
Jun 7 2000 05:11:19:390PM1000607024Ian HutchinsonPlasma. ICRF trips out.

Engineering Operator Comments
ShotTimeTypeStatusComment
108:55:28:047AMPlasmaOk
209:18:29:873AMPlasmaOk
309:38:33:590AMPlasmaOk
409:55:59:233AMPlasmaOk
510:16:15:123AMPlasmaOk
610:34:18:280AMPlasmaOk
710:52:18:577AMPlasmaOk
811:12:00:327AMPlasmaOk
911:30:16:623AMPlasmaOk
1011:49:13:263AMPlasmaOk
1112:12:03:090PMPlasmaOk
1212:31:13:890PMPlasmaOk
1312:52:23:733PMPlasmaOk
1401:13:44:890PMPlasmaOk
1501:34:46:437PMPlasmaOk
1601:57:03:623PMPlasmaOk
1702:20:05:280PMPlasmaOk
1802:43:32:500PMPlasmaOk
1903:05:17:343PMPlasmaOk
2003:24:39:123PMPlasmaOk
2103:42:36:170PMPlasmaOk
2203:59:24:717PMPlasmaOk
2304:17:20:967PMPlasmaOk
2404:36:25:983PMPlasmaOk
2504:56:37:513PMPlasmaOk