Alcator C-Mod Run 1030604 Information

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Miniproposals
Miniproposal:330a
Date Filed: 5/22/2003
Title:Edge Minority Heating for H-Mode Control
First Author:Stewart Zweben
Session Leader:Stewart Zweben (shots 18-32)
Session Leader:Jim Terry (shots 18-32)
Miniproposal:332
Date Filed: 4/8/2003
Title:A new approach to the study of turbulent edge plasma fluctuations.
First Author:Olaf Grulke
Session Leader:Olaf Grulke (shots 1-17)

Operators
Session leader(s):Olaf Grulke,Stewart Zweben,Jim Terry
Physics operator(s):Dmitri Mossessian
Engineering operator(s): Unknown

Engineering Operator Run Comment
MP 332 Turbulent Edge Plasma & MP 330 Edge minority heating; PO:Mossessi

Session Leader Plans

Physics Operators Plans

Session Leader Summaries
Entered: Jul 7 2004 03:49:32:867PM
Author: Steve Wukitch
Physop summary for the run of June 04, 2003.

Session leader: Grulke, Zweben, Terry
Physics operator: Mossessian

Run plan:

MP 332 - New approach to study of turbulent edge plasma
fluctuations

and then go to

MP 330 - Edge minority heating for H-mode control
and boronization recovery


Run Plan: The first half of the day will be devoted to MP 332 and to
boronization recovery of the antennas. The 2nd half will be devoted
to MP 330 (vary Btor to change RF resonance location from core to edges)

Use last shot from 06/03 for startup.

Load segment 2 from shot 1030603008.

1030604003:
Plasma request: 0.8 MA, 5.4 T, nl04 = 1 x 10^20 m^-2, normal SN diverted.
RF request:
D: [0.6, 1.] sec, 0.6-0.8 MW.
E: [0.6, 1.] sec, 0.6-0.8 MW.
J: [0.6, 1.] sec, 2 x .5 MW.
Result: plasma.
D: ran. 3 trips
E: ran. Max faults.
(phase balance faults) Move the phase threshold from 1140 to 2000.
J: ran. max faults.

Rick went into the power room. He re-plugged the modulator module of J3.
What we changed since last week on J3:
1. Replaced a mixer.
2. Changed the rising time constant capacitor.

1030604004:
Plasma request: 0.8 MA, 5.4 T, nl04 = 1 x 10^20 m^-2, normal SN diverted.
RF request:
D: [0.6, 1.] sec, 0.6-0.8 MW.
E: [0.6, 1.] sec, 0.6-0.8 MW.
J: [0.6, 1.] sec, 2 x .5 MW.
Result: plasma.
D: ran. 3 trips
E: ran. 10 faults
J: ran. J4 bad matching. tune the stub tuner again.

1030604005:
Plasma request: 0.8 MA, 5.4 T, nl04 = 1 x 10^20 m^-2, normal SN diverted.
RF request:
D: [0.6, 1.] sec, 0.7-0.9 MW.
E: [0.6, 1.] sec, 0.6-0.8 MW.
J: [0.6, 1.] sec, 2 x .5 MW.
Result: plasma.
D: ran. 5 faults.
E: ran. Many faults.
J: ran. max faults. Mostly J3 DC0.

Next: try lower edge density for the RF.


1030604006:
Plasma request: 0.8 MA, 5.4 T, nl04 = 0.9 x 10^20 m^-2, normal SN diverted.
RF request:
D: [0.6, 1.] sec, 0.7-0.9 MW.
E: [0.6, 1.] sec, 0.6-0.8 MW.
J: [0.6, 1.] sec, 2 x .5 MW.
Result: plasma.
D: ran. 8 faults.
E: ran. 8 faults.
J: ran. max faults. J4 matching bad. (Maybe because I changed the digital phase).

1030604007:
Plasma request: 0.8 MA, 5.4 T, nl04 = 0.9 x 10^20 m^-2, normal SN diverted.
RF request:
D: [0.6, 1.] sec, 0.6 MW
E: [0.6, 1.] sec, 0.5 MW
J: [0.6, 1.] sec, 2 x .5 MW.
Result: plasma.
D: ran. one fault.
E: ran. 5 faults.
J: ran. max faults. J4 matching still bad.

1030604008: Disrupted at 0.135 sec before the RF.

Test shot with MANUAL with J3. 0.1 MW to see whether we can still see
funny jumps in the J3 DC1 signals. No spikes.??
But we saw spikes when running with data cycling. Why??


1030604009:
Plasma request: 0.8 MA, 5.4 T, nl04 = 0.9 x 10^20 m^-2, normal SN diverted.
RF request:
D: [0.6, 1.] sec, 0.7 MW
E: [0.6, 1.] sec, 0.5 MW
J: [0.6, 1.] sec, 2 x .5 MW.
Result: plasma.
D: ran. clean
E: ran. 1 fault.
J: ran. Run 60 ms. max faults. J4 matching still bad.

1030604010:
Plasma request: 0.8 MA, 5.4 T, nl04 = 0.9 x 10^20 m^-2, normal SN diverted.
RF request:
D: [0.6, 1.] sec, 0.8 MW
E: [0.6, 1.] sec, 0.7 MW
J: [0.6, 1.] sec, 2 x .5 MW.
Result: plasma. H-mode
D: ran. 3 faults. Lost power control when the matching was good.
E: ran. 6 faults.
J: ran. max faults. Matching is still bad.

Changed the digitizer channels of J3DC1 forw and refl from cpci 21008 ch_1 and 2 to ch_11 and ch_12

1030604011: fizzle

1030604012:
Plasma request: 0.8 MA, 5.4 T, nl04 = 0.9 x 10^20 m^-2, normal SN diverted.
RF request:
D: [0.6, 1.] sec, 0.8 MW
E: [0.6, 1.] sec, 0.7 MW
J: [0.6, 1.] sec, 2 x .5 MW.
Result: plasma.
D: ran. clean
E: ran. 3 faults
J: ran. 7 faults

1030604013:
Plasma request: 0.8 MA, 5.4 T, nl04 = 0.9 x 10^20 m^-2, normal SN diverted.
RF request:
D: [0.6, 1.] sec, 0.8 MW
E: [0.6, 1.] sec, 0.7 MW
J: [0.6, 1.] sec, 2 x .5 MW.
Result: plasma.
D: ran. clean
E: ran. 3 faults
J: ran. 7 faults


Change the tuning program to fix dc1 fudge to calculate the DC2 fudge and stub fudge.
Found the prediction is now good.

1030604014: NO RF

1030604015:
Plasma request: 0.8 MA, 5.4 T, nl04 = 0.9 x 10^20 m^-2, normal SN diverted.
RF request:
D: [0.6, 1.] sec, 1.09 MW
E: [0.6, 1.] sec, 0.7 MW
J: [0.6, 1.] sec, 2 x .5 MW.
Result: plasma. disrupted at 0.93 sec.
D: ran. 3 faults.
E: ran. 6 faults.
J: ran. 3 faults.


1030604016: NO RF
1030604017: NO RF


1030604018:

Start MP330

Plasma request: 0.5 MA, 5.4 T, nl04 = 1 x 10^20 m^-2, normal SN diverted.
RF request:
D: [0.6, 1.] sec, 0.8 MW
E: [0.6, 1.] sec, 0.7 MW
J: [0.5, 1.5] sec, 2 x (0.25 - 1.0) MW. special waveform.
Result: plasma. disrupted at 0.82 sec.
D: ran. mis-matched.
E: ran. mismatched
J: ran. mismatched.

D and E already tuned to this plasma, but it is not required for the next shot.

1030604019:
Plasma request: 0.5 MA, 5.4 T, nl04 = 0.8 x 10^20 m^-2, normal SN diverted.
RF request:
J: [0.5, 1.5] sec, 2 x (0.25 - 1.0) MW. special waveform.
Result: plasma.
disrupted before RF on.


1030604020:
Plasma request: 0.5 MA, 5.4 T, nl04 = 0.6 x 10^20 m^-2, normal SN diverted.
RF request:
J: [0.5, 1.5] sec, 2 x (0.25 - 1.0) MW. special waveform.
Result: plasma.
J: ran. bad matching.

Next re-tune. Same waveform.

1030604021:
Plasma request: 0.6 MA, 5.4 T, nl04 = 0.6 x 10^20 m^-2, normal SN diverted.
RF request:
J: [0.5, 1.5] sec, 2 x (0.25 - 1.0) MW. special waveform.
Result: plasma.
J: ran. good matching. Getting better each retry.

1030604022:
Plasma request: 0.6 MA, 4.2 T, nl04 = 0.6 x 10^20 m^-2, normal SN diverted.
RF request:
J: [0.5, 1.5] sec, 2 x (0.25 - 1.0) MW. special waveform.
Result: plasma.
J: ran. good matching. 4 faults.

1030604023:
Plasma request: 0.6 MA, 3.8 T, nl04 = 0.6 x 10^20 m^-2, normal SN diverted.
RF request:
J: [0.5, 1.5] sec, 2 x (0.25 - 1.0) MW. special waveform.
Result: plasma. Lots of H-modes.
J: ran. good matching. only one fault.

1030604024:
Plasma request: 0.6 MA, 3.8 T, nl04 = 0.6 x 10^20 m^-2, normal SN diverted.
RF request:
J: [0.5, 1.5] sec, 2 x (0.1 - .4) MW. special waveform.
Result: plasma. Lots of H-modes.
J: ran. good matching. clean.

1030604025:
Plasma request: 0.56 MA, 3.65 T, nl04 = 0.6 x 10^20 m^-2, normal SN diverted.
RF request:
J: [0.5, 1.5] sec, 2 x (0.1 - .4) MW. special waveform.
Result: plasma. Lots of H-modes.
J: ran. good matching. clean.

1030604026:
Plasma request: 0.56 MA, 3.65 T, nl04 = 0.6 x 10^20 m^-2, normal SN diverted.
RF request:
J: [0.5, 1.5] sec, 2 x (0.1 - .4) MW. special waveform.
Result: plasma. Lots of H-modes.
J: ran. good matching. clean.


1030604027:
Plasma request: 0.56 MA, 3.65 T, nl04 = 0.6 x 10^20 m^-2, normal SN diverted.
RF request:
J: [0.5, 1.5] sec, 2 x (0.1 - .3) MW. special waveform.
Result: plasma. Lots of H-modes.
J: ran. good matching. clean.

1030604028:
Plasma request: 0.56 MA, 3.65 T, nl04 = 0.6 x 10^20 m^-2, normal SN diverted.
RF request:
J: [0.5, 1.5] sec, 2 x (0.1 - 1.0) MW. special waveform.
Result: plasma. Lots of H-modes.
J: ran. good matching. tripped at 2 MW level.

1030604029:
Plasma request: 0.56 MA, 3.65 T, nl04 = 0.6 x 10^20 m^-2, normal SN diverted.
RF request:
J: [0.5, 1.5] sec, 2 x (0.1 - 0.4) MW. special waveform.
Result: plasma. Lots of H-modes.
J: ran. good matching.

Summary:

Antenna conditioning was limited due to priority given to the other
MPs. The conditioning of D and E-port was limited to ~0.8 MW and
J-port was somewhat less. We made good progress in determining the
calibration data required for calculating reliable matching numbers.

Entered: Jul 7 2004 03:49:32:880PM
Author: Jim Terry
This run has been split between MP 332 (morning - piggy back) and MP 330a (afternoon).
This report addresses the MP 332 piggyback part of the experiment and the MP 330a part
of the experiment.

For the MP 332 part ---------------------------------------------------------------

We desire to find experimentally at which field and current the F-probe magnetically
maps to the observation region of the GPI system. This is in order to make a
simultaneous spatiotemporal measurement of plasma density and plasma potential
fluctuations.

The mapping should occur at B_t=5.4 T and I_p between 570 and 630 kA. We will plunge the probe
at currents of 570kA, 585 kA, 600 kA, 615kA, and 630kA and look at the
cross-correlation between I-sat and V-floating signals
on the probe and the light fluctuations on the radial array of GPI views.


On this day 1030603 only 2 different current values could be tested:

# 1030603008: 600kA (time of probe plunge maximum=1.3 and 1.5 s; diode data @300kHz)
# 1030603021: 590kA (time of probe plunge maximum=1.25 s; diode data @300kHz)

The efit reconstruction shows clear mapping and a significant correlation
between the F-probe data and the diode data was found, mainly consistent with
the calculations. Shots for the other proposed current values are re-scheduled
for 06.04.2003.


On 1030604 we continued the piggyback turbulence mapping experiments of
06-03-2003. The plasma currents were varied between 590-640kA in 8 successful
shots:

# 1030604005: I_p=600kA (time of probe plunge maximum=1.25 s; diode data @1 MHz)
# 1030604006: I_p=600kA, slightly lower density (time of probe plunge maximum=1.25 s; diode data @1 MHz)
# 1030604007: I_p=590kA (time of probe plunge maximum=1.25 s; diode data @1 MHz)
# 1030604009: I_p=590kA (time of probe plunge maximum=1.25 s; diode data @1 MHz)
# 1030604010: I_p=620kA (time of probe plunge maximum=1.25 s; diode data @1 MHz)
# 1030604014: I_p=620kA, density raised to nl=1.2e20 (time of probe plunge maximum=1.25 s; diode data @1 MHz)
# 1030604016: I_p=610kA, density decreased to nl=1e20 (time of probe plunge maximum=1.25 s; diode data @1 MHz)
# 1030604017: I_p=640kA (time of probe plunge maximum=1.25 s; diode data @1 MHz)



RESULTS:

1. Correlation analysis shows a typical correlation between F-probe and diode
data of 25-30%, which is clearly above the noise level. The higher correlation values were
with the floating potential signals while the 0.25 value was for correlations with I_sat.
The noise level of the correlation was typically <0.1.

2. For different plasma currents the correlation was found generally in agreement
with the respective efit calculations. Typically an "above-noise" correlation
was seen on ~3 diode views, centered on the view consistent with the EFIT mapping.

3. A localized influence of the F-probe was clearly visible in the diode raw data and
indications are also observed in the PSI camera images.

4. An increase in density from nl=1e20 to nl=1.2e20 seems to decrease the
correlation.


Entered: Jul 7 2004 03:49:32:897PM
Author: Stewart Zweben

MP 330a ----------------------------------------------------------------------------

The purpose of the MP 330a part of the experiment is to test whether edge fast ion loss
can affect the edge radial electric field and the H-mode transition in C-Mod.

The primary results of of this 1/2 day experiment were:
1) with the resonance on the inboard edge of the plasma (R_res=47 cm),
the concensus among the various diagnostics was that
NO H-mode was obtained at powers up to 2.2 MW
2) with the resonance on the outboard edge of the plasma (R_res=87 cm),
NO H-mode was obtained at powers up to 1.0 MW
3) there were H-modes produced at .89 MW for resonance locations of 67 cm
(i.e. central heating), 76 cm, and possibly a por H-mode at R_res=85 cm.
Thus we conclude that we were not able to produce an H-mode in the
manner hypothesized, i.e. appliy RF at the inboard and outboared edges in hopes of
creating an edge radial electric field via fast ion loss.

EXPERIMENTAL PLAN
The RF will be pulsed several times during the shot at varying durations and power
levels to determine the minimum power required to create an H-mode. The H-mode will
be diagnosed by the usual Da signals and by the Thompson scattering profiles. A
Langmuir probe will be scanned to help determine whether the edge plasma potential
is being affected by the RF.

Variation of the minority resonance position will be made through scans of the toridal
field. The effect on the edge RF on the H-mode triggering should decrease with increasing
plasma current (due to decreased orbit loss) and decrease with increased gas puff
(due to higher edge density and lower RF tail formation), so variations of these
quantities will also be made if time allows.

The sequence of desired conditions is:

Assume RF frequency of 78 MHz and TF referenced to R=66cm. Setup:

1) setup standard SN Ohmic discharge with B=5.4 T, I=0.5 MA, with pulse length about 1.5 sec,
nominal 1 cm inner and outer gaps.

2) at B=5.4 T, add 0.5-2 MW RF at 78 MHz (J-port) with RH = 69.5 cm with pulse sequence of
RF powers stepped-up from 0.5 MW, 1.0, 1.5 2.0 MW, with RF pulse duration = 50 msec.

High-field side resonance scan:

3) decrease to B=4.11 T and apply RF pulse @ RH = 53 cm

4) decrease to B=3.88 T and apply RF pulse @ RH = 50 cm

5) decrease to B=3.65 T and apply RF pulse @ RH = 47 cm

6) ramp B from 4.11 to 3.57 T over 0.5 - 1.0 sec with RH = 53-46 cm at constant RF power
(somewhere between 0.5-2 MW)

Low-field side resonance scan:

(note: start at 0.5 MW RF power in 50 msec pulses for steps 7-11 and discontinue outward
scan if arcing occurs at antenna. If no arcing occurs and no H-mode occurs, then repeat
#7-11 at 1.0 MW, then 1.5 and 2.0 MW, again discontinuing if arcing occurs at antenna)

7) increase to B = 6.14 T and apply 0.5 MW RF pulses @ RH = 79 cm

8) increase to B = 6.37 T and apply 0.5 MW RF pulses @ RH = 82 cm

9) increase to B = 6.60 T and apply 0.5 MW RF pulses @ RH = 85 cm

10) increase to B = 6.84 T and apply 0.5 MW RF pulses @ RH = 88 cm

11) ramp B from 6.0 to 6.9 T over 0.5 - 1.0 sec with RH = 77.2-88.8 cm at 0.5 MW RF power

12) repeat #7-11 at 1.0 MW, then 1.5 MW, then 2.0 MW if time allows



Parts 2, 3, 4, 5, 7, 8, and 9 were accomplished.

Shot by shot summary of MP 330a part of run - took over at shot 018:

shot 1030604018
Bt=5.4 T
I_p to ramp down to 0.5 MA
Shot detaches poloidally at 0.56 s and disrupts at 0.81s


shot 1030604019
Bt=5.4 T
I_p to ramp down to 0.5 MA
Shot disrupts at 0.47s


shot 1030604020
Bt=5.4 T
I_p ramps down to 0.58 MA
Shot OK, but no RF.

shot 1030604021
Bt=5.4 T
I_p ramps down to 0.58 MA
Shot OK, RF power steps up to 1.1 MW, probable
short H-mode at 1 s, with RF at 1.1 MW

shot 1030604022
Bt=4.2 T
I_p ramps down to 0.58 MA
Shot OK, RF power steps up to 1.6 MW,
possible H-modes even at the lowest RF power (0.5 MW).
Ha signature of H-mode is not present.

shot 1030604023
Bt=3.8 T
I_p ramps down to 0.58 MA
Shot OK, 2 sets of 4 RF power steps up to 2.2 MW,
possible H-modes even at the lowest RF power (0.5 MW)

shot 1030604024
repeat, but with smaller RF power steps
Bt=3.8 T
I_p ramps down to 0.58 MA
Shot OK, RF power steps of 0.2, 0.4, 0.6, 0.9 MW,
possible H-modes even at RF power of 0.4 MW

shot 1030604025
repeat, but with smaller RF power steps
Bt=3.65 T
I_p ramps down to 0.58 MA
Shot OK, RF power steps of 0.2, 0.4, 0.6, 0.9 MW,
possible H-modes even at RF power of 0.4 MW, but
no H-mode edge with these short pulses

shot 1030604026
repeat
Bt=3.65 T
I_p ramps down to 0.58 MA
Shot OK, RF power steps of 0.2, 0.4, 0.6, 0.9 MW,
possible H-modes even at RF power of 0.4 MW, but
no H-mode edge.

shot 1030604027
lengthen the RF pulses to reach steady-state condition.
Bt=3.65 T
I_p ramps down to 0.58 MA
Shot OK, 200 ms RF power steps of 0.2, 0.4, 0.6 MW,
no H-mode pedestal on any step, Dalsa reports edge profile
change at 0.4 MW pulse.

shot 1030604028
increase RF power in the last pulse
Bt=3.65 T
I_p ramps down to 0.58 MA
Shot OK, 200 ms RF power steps of 0.2, 0.4, 2.2 MW (with trips),
no H-mode pedestal on any step. Consensus: no H-mode

shot 1030604029
now go to outboard resonance
Bt=5.95 T
I_p ramps down to 0.59 MA
Shot OK, 200 ms RF power steps of 0.2, 0.44, 0.87 MW (with trip),
clear H-mode on last RF pulse 1.35s to 1.5 s.

shot 1030604030
Bt=6.64 T
I_p ramps down to 0.59 MA
Shot OK, 200 ms RF power steps of 0.2, 0.4 (with trips), 0.87 MW (with trip),
rising edge Te on last RF pulse 1.35s to 1.5 s. No density pedestal
according to Dalsa. Antenna arc during last RF pulse.

shot 1030604031
go back to central resonance to see if we get H-mode at 0.8 MW.
Bt=5.4 T, I_p ramps down to 0.59 MA
Shot OK, 200 ms RF power steps of 0.2, 0.4, 0.89 MW,
clear H-mode during last RF pulse (0.89 MW).

shot 1030604032
move resonance to around 87 cm (furthest yet)
Bt=6.75 T
I_p ramps down to 0.59 MA
Shot OK, 50 ms RF power steps of 0.5, 1.0 (with trips) , 1.5 MW (with trips),
no H-mode.


Physics Operator Summaries
Entered: Jul 7 2004 04:37:18:100PM
Author: Dmitri Mossessian
Physop summary fro the run of June 04, 2003.

Session leader: Grulke, Zweben, Terry
Physics operator: Mossessian

Run plan:

MP 332 - New approach to study of turbulent edge plasma
fluctuations

and then go to

MP 330 - Edge minority heating for H-mode control
and boronization recovery


Run Plan: The first half of the day will be devoted to MP 332 and to
boronization recovery of the antennas. The 2nd half will be devoted
to MP 330 (vary Btor to change RF resonance location from core to edges)

Use last shot from 06/03 for startup.

Load segment 2 from shot 1030603008.
________________________________________________-

Summary:

Part 1 - Boronization recovery went very well. After overnight ECDC no problems with startup were observed.
An injection at around 0.1 sec (when control goes from segment 1 to segment 2) was observed on many shots.
On shot 8 it killed the plasma. We tried to tweak current and RCUR and ZCUR to get a better match bewteen
requested values at the beginning of Segment 2 and the end of Segment 1. The injection did not go away completely,
but became much smaller.
The startup was very smooth up to shot 10. On shot 11 the plasma bounced and fizzled. Playing with prepuff helped,
but the bounce was observed on almost every second shot since. The current always survived, so no changes of
startup were attempted.

Shots from 1 to 17 were dedicated to MP332, shots 18 to 32 dealt with MP330. The Bt was varied from 3.68 to 6.75 T
(see details below)

Total:

32 shots
1 fizzle
1 test
1 dud
29 plasmas

Details:

----------------------------------------------------------------------------
. . . . . . . . . . . . . . . . . . .
1030604001 mossessian PHYSICS_OPERATOR Jun 4 2003 9:12:17:370AM
. . . . . . . . . . . . . . . . . . . .
Power cycle test.
----------------------------------------------------------------------------
1030604002 mossessian PHYSICS_OPERATOR Jun 4 2003 9:13:26:463AM
. . . . . . . . . . . . . . . . . . . .
Dud. Probably because no ECDC was done after RF conditionning in the morning.

Do ECDC for 10 min.

Next shot - no PCS changes.
----------------------------------------------------------------------------
1030604003 mossessian PHYSICS_OPERATOR Jun 4 2003 9:36:12:016AM
. . . . . . . . . . . . . . . . . . . .
Plasma. Good startup.

Next shot - no PCS changes.
----------------------------------------------------------------------------
1030604005 mossessian PHYSICS_OPERATOR Jun 4 2003 10:08:39:333AM
. . . . . . . . . . . . . . . . . . . .
Plasma. Good startup

Next shot; nl04 down to 9e19
----------------------------------------------------------------------------
1030604006 mossessian PHYSICS_OPERATOR Jun 4 2003 10:16:04:003AM
. . . . . . . . . . . . . . . . . . . .
Plasma. Good startup

Next shot; nl04 down to 8e19, drop current in second phase by 10 kA (from 640 kA to 630 kA programmed,
corresponding to 600 -> 590 real)
----------------------------------------------------------------------------
1030604007 mossessian PHYSICS_OPERATOR Jun 4 2003 10:35:12:853AM
. . . . . . . . . . . . . . . . . . . .
Plasma. Good startup

Next shot; nl04 down to 7e19, drop current in second phase by another 10 kA
----------------------------------------------------------------------------
1030604008 mossessian PHYSICS_OPERATOR Jun 4 2003 11:13:03:666AM
. . . . . . . . . . . . . . . . . . . .
Plasma. Good startup. Disrupted due to large injection at .135
The smaller injection at the same time was seen on previous shot

Next shot: Lower RCUR by 5 mm in segment 1 and 2 around .1 sec - we suspect that plasma touched the outer limiter.
Also, segment 2 asks for 450 kA at 0.1 sec, while real current is already >600 kA.
Changed requested current to 600 kA at .1 sec in segment 2.

----------------------------------------------------------------------------
1030604009 mossessian PHYSICS_OPERATOR Jun 4 2003 11:16:37:743AM
. . . . . . . . . . . . . . . . . . . .
Plasma. Good startup. The injection at .1 is still there, although small.

Next shot: Ip up 30 kA in second phase
----------------------------------------------------------------------------
1030604010 mossessian PHYSICS_OPERATOR Jun 4 2003 11:34:19:143AM
. . . . . . . . . . . . . . . . . . . .
Plasma. Good startup. The injection at .1 is still there, although small.

Next shot: ZCUR from -9 mm to -1 mm in segment 2 at .1 sec to match segment 1.
nl04 steped up to 1.2e20 after 1 sec
----------------------------------------------------------------------------
1030604011 mossessian PHYSICS_OPERATOR Jun 4 2003 11:49:39:780AM
. . . . . . . . . . . . . . . . . . . .
Fizzle. Bounced on outer wall at .018 sec.

Next shot - prepuff 25 -> 27 msec to slow current rise and get rid of outer wall bounce.
CLEARIN down 2 mm after 1 sec
----------------------------------------------------------------------------
1030604012 mossessian PHYSICS_OPERATOR Jun 4 2003 11:56:42:183AM
. . . . . . . . . . . . . . . . . . . .
Plasma. Disrupts at .85 sec. Current rise slower in segment 1. Almost got rid of injection at .1 sec

Next shot: prepuff down 27 ms -> 26 ms
----------------------------------------------------------------------------
1030604013 mossessian PHYSICS_OPERATOR Jun 4 2003 12:24:41:406PM
. . . . . . . . . . . . . . . . . . . .
Plasma. Disrupts at .9 sec. Startup is not happy - bounces at 0.015, two injection before 0.1

Next shot: no PCS change. RF off
----------------------------------------------------------------------------
1030604014 mossessian PHYSICS_OPERATOR Jun 4 2003 12:33:29:073PM
. . . . . . . . . . . . . . . . . . . .
Plasma. Disrupts during rampdown. Startup improved.

Next shot: nl04 down to 1e20 in second phase. RF back on.
----------------------------------------------------------------------------
1030604015 mossessian PHYSICS_OPERATOR Jun 4 2003 12:58:06:550PM
. . . . . . . . . . . . . . . . . . . .
Plasma. RF back on and plasma disrupts at .9 sec

Next shot: No PCS changes. RF power down
----------------------------------------------------------------------------
1030604016 mossessian PHYSICS_OPERATOR Jun 4 2003 1:05:47:186PM
. . . . . . . . . . . . . . . . . . . .
Plasma.

Next shot: Ip up 20 kA in the second phase
----------------------------------------------------------------------------
1030604017 mossessian PHYSICS_OPERATOR Jun 4 2003 1:20:17:730PM
. . . . . . . . . . . . . . . . . . . .
Plasma.

Next shot: go to MP330. Set up 5.4 T, 500 kA, 1e20 target
----------------------------------------------------------------------------
1030604018 mossessian PHYSICS_OPERATOR Jun 4 2003 1:42:48:640PM
. . . . . . . . . . . . . . . . . . . .
Plasma. Poloidal detachment at .57, then disruption after RF.

Next shot: lower target to .75e20
----------------------------------------------------------------------------
1030604019 mossessian PHYSICS_OPERATOR Jun 4 2003 1:59:41:386PM
. . . . . . . . . . . . . . . . . . . .
Plasma. Disrupts at .48 s

Next shot: lower target to .6e20, current up to 600 kA
----------------------------------------------------------------------------
1030604020 mossessian PHYSICS_OPERATOR Jun 4 2003 2:05:29:446PM
. . . . . . . . . . . . . . . . . . . .
Plasma.

Next shot: No changes
----------------------------------------------------------------------------
1030604021 mossessian PHYSICS_OPERATOR Jun 4 2003 2:23:02:580PM
. . . . . . . . . . . . . . . . . . . .
Plasma.

Next shot: Bt to 4.11 T (TF 150 -> 114), target to 5e19
----------------------------------------------------------------------------
1030604022 mossessian PHYSICS_OPERATOR Jun 4 2003 2:36:34:136PM
. . . . . . . . . . . . . . . . . . . .
Plasma.

Next shot: Bt to 3.8 T (TF 114 -> 103)
----------------------------------------------------------------------------
1030604023 mossessian PHYSICS_OPERATOR Jun 4 2003 2:51:15:723PM
. . . . . . . . . . . . . . . . . . . .
Plasma.

Next shot: no changes
----------------------------------------------------------------------------
1030604024 mossessian PHYSICS_OPERATOR Jun 4 2003 3:04:47:750PM
. . . . . . . . . . . . . . . . . . . .
Plasma.

Next shot: Bt down to 3.6 (TF -> 99)
----------------------------------------------------------------------------
1030604025 mossessian PHYSICS_OPERATOR Jun 4 2003 3:32:25:583PM
. . . . . . . . . . . . . . . . . . . .
Plasma. Bt=3.68 T

Next shot: repeat with longer RF pulses.
----------------------------------------------------------------------------
1030604026 mossessian PHYSICS_OPERATOR Jun 4 2003 3:32:40:600PM
. . . . . . . . . . . . . . . . . . . .
Plasma. Bt=3.68 T

Next shot: no changes
----------------------------------------------------------------------------
1030604028 mossessian PHYSICS_OPERATOR Jun 4 2003 4:09:12:000PM
. . . . . . . . . . . . . . . . . . . .
Plasma.

Next shot: Go to 6.14 T (TF -> 170)
----------------------------------------------------------------------------
1030604029 mossessian PHYSICS_OPERATOR Jun 4 2003 4:17:15:230PM
. . . . . . . . . . . . . . . . . . . .
Plasma.

Next shot: Go to 6.4 T (TF -> 185)
----------------------------------------------------------------------------
1030604030 mossessian PHYSICS_OPERATOR Jun 4 2003 4:36:46:100PM
. . . . . . . . . . . . . . . . . . . .
Plasma. Bt=6.6 T

Next shot: back to Bt=5.4 T
----------------------------------------------------------------------------
1030604031 mossessian PHYSICS_OPERATOR Jun 4 2003 5:01:57:510PM
. . . . . . . . . . . . . . . . . . . .
Plasma.

Next shot: go to Bt=6.8 T (TF -> 188)




Session Leader Comments
Jun 4 2003 02:51:55:927PMJim TerryThis run has been split between MP 332 (morning - piggy back) and MP 330a (afternoon).
This report addresses the MP 332 piggyback part of the experiment and the MP 330a part
of the experiment.

For the MP 332 part ---------------------------------------------------------------

We desire to find experimentally at which field and current the F-probe magnetically
maps to the observation region of the GPI system. This is in order to make a
simultaneous spatiotemporal measurement of plasma density and plasma potential
fluctuations.

The mapping should occur at B_t=5.4 T and I_p between 570 and 630 kA. We will plunge the probe
at currents of 570kA, 585 kA, 600 kA, 615kA, and 630kA and look at the
cross-correlation between I-sat and V-floating signals
on the probe and the light fluctuations on the radial array of GPI views.

MP 330a ----------------------------------------------------------------------------

The purpose of the MP 330a part of the experiment is to test whether edge fast ion loss
can affect the edge radial electric field and the H-mode transition in C-Mod.
The RF will be pulsed several times during the shot at varying durations and power
levels to determine the minimum power required to create an H-mode. The H-mode will
be diagnosed by the usual Da signals and by the Thompson scattering profiles. A
Langmuir probe will be scanned to help determine whether the edge plasma potential
is being affected by the RF.

Variation of the minority resonance position will be made through scans of the toridal
field. The effect on the edge RF on the H-mode triggering should decrease with increasing
plasma current (due to decreased orbit loss) and decrease with increased gas puff
(due to higher edge density and lower RF tail formation), so variations of these
quantities will also be made if time allows.

The sequence of desired conditions is:

Assume RF frequency of 78 MHz and TF referenced to R=66cm. Setup:

1) setup standard SN Ohmic discharge with B=5.4 T, I=0.5 MA, with pulse length about 1.5 sec,
nominal 1 cm inner and outer gaps.

2) at B=5.4 T, add 0.5-2 MW RF at 78 MHz (J-port) with RH = 69.5 cm with pulse sequence of
RF powers stepped-up from 0.5 MW, 1.0, 1.5 2.0 MW, with RF pulse duration = 50 msec.

High-field side resonance scan:

3) decrease to B=4.11 T and apply RF pulse @ RH = 53 cm

4) decrease to B=3.88 T and apply RF pulse @ RH = 50 cm

5) decrease to B=3.65 T and apply RF pulse @ RH = 47 cm

6) ramp B from 4.11 to 3.57 T over 0.5 - 1.0 sec with RH = 53-46 cm at constant RF power
(somewhere between 0.5-2 MW)

Low-field side resonance scan:

(note: start at 0.5 MW RF power in 50 msec pulses for steps 7-11 and discontinue outward
scan if arcing occurs at antenna. If no arcing occurs and no H-mode occurs, then repeat
#7-11 at 1.0 MW, then 1.5 and 2.0 MW, again discontinuing if arcing occurs at antenna)

7) increase to B = 6.14 T and apply 0.5 MW RF pulses @ RH = 79 cm

8) increase to B = 6.37 T and apply 0.5 MW RF pulses @ RH = 82 cm

9) increase to B = 6.60 T and apply 0.5 MW RF pulses @ RH = 85 cm

10) increase to B = 6.84 T and apply 0.5 MW RF pulses @ RH = 88 cm

11) ramp B from 6.0 to 6.9 T over 0.5 - 1.0 sec with RH = 77.2-88.8 cm at 0.5 MW RF power

12) repeat #7-11 at 1.0 MW, then 1.5 MW, then 2.0 MW if time allows
Jun 4 2003 02:58:49:753PM1030604018Jim TerryStart the MP 330a part of the run:

Bt=5.4 T
I_p to ramp down to 0.5 MA

Shot detaches poloidally at 0.56 s and disrupts at 0.81s
Jun 4 2003 03:00:27:627PM1030604019Jim TerryBt=5.4 T
I_p to ramp down to 0.5 MA

Shot disrupts at 0.47s
Jun 4 2003 03:01:58:360PM1030604020Jim TerryBt=5.4 T
I_p ramps down to 0.58 MA

Shot OK, but no RF.
Jun 4 2003 03:04:59:530PM1030604021Jim TerryBt=5.4 T
I_p ramps down to 0.58 MA

Shot OK, RF power steps up to 1.1 MW, probable H-mode at 1 s, with RF at 1.1 MW
Jun 4 2003 03:11:21:000PM1030604022Jim TerryBt=4.2 T
I_p ramps down to 0.58 MA

Shot OK, RF power steps up to 1.6 MW,
probable H-modes even at the lowest RF power (0.5 MW)
Jun 4 2003 03:11:54:653PM1030604023Jim TerryBt=3.8 T
I_p ramps down to 0.58 MA

Shot OK, 2 sets of 4 RF power steps up to 2.2 MW,
probable H-modes even at the lowest RF power (0.5 MW)
Jun 4 2003 03:17:32:370PM1030604024Jim Terryrepeat, but with smaller RF power steps
Bt=3.8 T
I_p ramps down to 0.58 MA

Shot OK, RF power steps of 0.2, 0.4, 0.6, 0.9 MW,
probable H-modes even at RF power of 0.4 MW
Jun 4 2003 03:31:25:570PM1030604025Jim Terryrepeat, but with smaller RF power steps
Bt=3.65 T
I_p ramps down to 0.58 MA

Shot OK, RF power steps of 0.2, 0.4, 0.6, 0.9 MW,
probable H-modes even at RF power of 0.4 MW, but
no H-mode edge with these short pulses
Jun 4 2003 03:47:47:430PM1030604026Jim Terryrepeat
Bt=3.65 T
I_p ramps down to 0.58 MA

Shot OK, RF power steps of 0.2, 0.4, 0.6, 0.9 MW,
possible H-modes even at RF power of 0.4 MW, but
no H-mode edge.
Jun 4 2003 03:53:22:960PM1030604027Jim Terrylengthen the RF pulses to reach steady-state condition.
Bt=3.65 T
I_p ramps down to 0.58 MA

Shot OK, 200 ms RF power steps of 0.2, 0.4, 0.6 MW,
no H-mode pedestal on any step, Dalsa reports pedge profile
change at 0.4 MW pulse.
Jun 4 2003 04:15:30:480PM1030604028Jim Terryincrease RF power in the last pulse
Bt=3.65 T
I_p ramps down to 0.58 MA

Shot OK, 200 ms RF power steps of 0.2, 0.4, 2.2 MW (with trips),
no H-mode pedestal on any step. Consensus: no H-mode
Jun 4 2003 04:18:56:010PM1030604029Jim Terrynow go to outboard resonance
Bt=5.95 T
I_p ramps down to 0.59 MA

Shot OK, 200 ms RF power steps of 0.2, 0.44, 0.87 MW (with trip),
clear H-mode on last RF pulse 1.35s to 1.5 s.
Jun 4 2003 04:52:22:170PM1030604030Jim TerryBt=6.64 T
I_p ramps down to 0.59 MA

Shot OK, 200 ms RF power steps of 0.2, 0.4 (with trips), 0.87 MW (with trip),
rising edge Te on last RF pulse 1.35s to 1.5 s. No density pedestal
according to Dalsa. Antenna arc during last RF pulse.
Jun 4 2003 04:54:22:997PM1030604031Jim Terrygo back to central resonance to see if we get H-mode at 0.8 MW.
Bt=5.4 T
I_p ramps down to 0.59 MA

Shot OK, 200 ms RF power steps of 0.2, 0.4, 0.89 MW,
clear H-mode during last RF pulse (0.89 MW).
Jun 4 2003 05:04:48:667PM1030604032Jim Terrymove resonance to around 87-87 cm (furthest yet)
Bt=6.75 T
I_p ramps down to 0.59 MA

Shot OK, 50 ms RF power steps of 0.5, 1.0 (with trips) , 1.5 MW (with trips),
no H-mode.

Physics Operator Comments
Jun 4 2003 09:10:33:917AMDmitri MossessianMP 332 - New approach to study of turbulent edge plasma
fluctuations

and then go to

MP 330 - Edge minority heating for H-mode control
and boronization recovery

Run Plan: The first half of the day will be devoted to MP 332 and to
boronization recovery of the antennas. The 2nd half will be devoted
to MP 330 (vary Btor to change RF resonance location from core to edges)

Use last shot from 06/03 for startup.

Load segment 2 from shot 1030603008.



Jun 4 2003 09:12:17:370AM1030604001Dmitri MossessianPower cycle test.
Jun 4 2003 09:13:26:463AM1030604002Dmitri MossessianDud. Probably because no ECDC was done after RF conditionning in the morning.

Do ECDC for 10 min.

Next shot - no PCS changes.
Jun 4 2003 09:36:12:017AM1030604003Dmitri MossessianPlasma. Good startup.

Next shot - no PCS changes.
Jun 4 2003 10:08:39:333AM1030604005Dmitri MossessianPlasma. Good startup

Next shot; nl04 down to 9e19
Jun 4 2003 10:16:04:003AM1030604006Dmitri MossessianPlasma. Good startup

Next shot; nl04 down to 8e19, drop current in second phase by 10 kA (from 640 kA to 630 kA programmed,
corresponding to 600 -> 590 real)
Jun 4 2003 10:35:12:853AM1030604007Dmitri MossessianPlasma. Good startup

Next shot; nl04 down to 7e19, drop current in second phase by another 10 kA
Jun 4 2003 11:13:03:667AM1030604008Dmitri MossessianPlasma. Good startup. Disrupted due to large injection at .135
The smaller injection at the same time was seen on previous shot

Next shot: Lower RCUR by 5 mm in segment 1 and 2 around .1 sec - we suspect that plasma touched the outer limiter.
Also, segment 2 asks for 450 kA at 0.1 sec, while real current is already >600 kA.
Changed requested current to 600 kA at .1 sec in segment 2.

Jun 4 2003 11:16:37:743AM1030604009Dmitri MossessianPlasma. Good startup. The injection at .1 is still there, although small.

Next shot: Ip up 30 kA in second phase
Jun 4 2003 11:34:19:143AM1030604010Dmitri MossessianPlasma. Good startup. The injection at .1 is still there, although small.

Next shot: ZCUR from -9 mm to -1 mm in segment 2 at .1 sec to match segment 1.
nl04 steped up to 1.2e20 after 1 sec
Jun 4 2003 11:49:39:780AM1030604011Dmitri MossessianFizzle. Bounced on outer wall at .018 sec.

Next shot - prepuff 25 -> 27 msec to slow current rise and get rid of outer wall bounce.
CLEARIN down 2 mm after 1 sec
Jun 4 2003 11:56:42:183AM1030604012Dmitri MossessianPlasma. Disrupts at .85 sec. Current rise slower in segment 1. Almost got rid of injection at .1 sec

Next shot: prepuff down 27 ms -> 26 ms
Jun 4 2003 12:24:41:407PM1030604013Dmitri MossessianPlasma. Disrupts at .9 sec. Startup is not happy - bounces at 0.015, two injection before 0.1

Next shot: no PCS change. RF off
Jun 4 2003 12:33:29:073PM1030604014Dmitri MossessianPlasma. Disrupts during rampdown. Startup improved.

Next shot: nl04 down to 1e20 in second phase. RF back on.
Jun 4 2003 12:58:06:550PM1030604015Dmitri MossessianPlasma. RF back on and plasma disrupts at .9 sec

Next shot: No PCS changes. RF power down
Jun 4 2003 01:05:47:187PM1030604016Dmitri MossessianPlasma.

Next shot: Ip up 20 kA in the second phase
Jun 4 2003 01:20:17:730PM1030604017Dmitri MossessianPlasma.

Next shot: go to MP330. Set up 5.4 T, 500 kA, 1e20 target
Jun 4 2003 01:42:48:640PM1030604018Dmitri MossessianPlasma. Poloidal detachment at .57, then disruption after RF.

Next shot: lower target to .75e20
Jun 4 2003 01:59:41:387PM1030604019Dmitri MossessianPlasma. Disrupts at .48 s

Next shot: lower target to .6e20, current up to 600 kA
Jun 4 2003 02:05:29:447PM1030604020Dmitri MossessianPlasma.

Next shot: No changes
Jun 4 2003 02:23:02:580PM1030604021Dmitri MossessianPlasma.

Next shot: Bt to 4.11 T (TF 150 -> 114), target to 5e19
Jun 4 2003 02:36:34:137PM1030604022Dmitri MossessianPlasma.

Next shot: Bt to 3.8 T (TF 114 -> 103)
Jun 4 2003 02:51:15:723PM1030604023Dmitri MossessianPlasma.

Next shot: no changes
Jun 4 2003 03:04:47:750PM1030604024Dmitri MossessianPlasma.

Next shot: Bt down to 3.6 (TF -> 99)
Jun 4 2003 03:32:25:583PM1030604025Dmitri MossessianPlasma. Bt=3.68 T

Next shot: repeat with longer RF pulses.
Jun 4 2003 03:32:40:600PM1030604026Dmitri MossessianPlasma. Bt=3.68 T

Next shot: no changes
Jun 4 2003 04:09:12:000PM1030604028Dmitri MossessianPlasma.

Next shot: Go to 6.14 T (TF -> 170)
Jun 4 2003 04:17:15:230PM1030604029Dmitri MossessianPlasma.

Next shot: Go to 6.4 T (TF -> 185)
Jun 4 2003 04:36:46:100PM1030604030Dmitri MossessianPlasma. Bt=6.6 T

Next shot: back to Bt=5.4 T
Jun 4 2003 05:01:57:510PM1030604031Dmitri MossessianPlasma.

Next shot: go to Bt=6.8 T (TF -> 188)

Engineering Operator Comments
ShotTimeTypeStatusComment
108:18:08:937AMTestOkCycle Test
209:09:18:263AMPlasmaOk
309:28:01:490AMPlasmaOk
409:42:17:577AMPlasmaOk
509:56:19:087AMPlasmaOk
610:09:49:207AMPlasmaOk
710:27:18:357AMPlasmaOk
810:42:11:570AMPlasmaOk
911:02:28:220AMPlasmaOk
1011:18:32:040AMPlasmaOk
1111:34:29:130AMPlasmaOk
1211:50:43:217AMPlasmaOk
1312:06:41:397PMPlasmaOk
1412:21:26:313PMPlasmaOk
1512:35:38:340PMPlasmaOk
1612:55:24:050PMPlasmaOk
1701:10:19:747PMPlasmaOk
1801:28:33:477PMPlasmaOk
1901:44:01:843PMPlasmaOk
2002:00:41:540PMPlasmaOk
2102:16:41:800PMPlasmaOk
2202:29:49:500PMPlasmaOk
2302:42:48:400PMPlasmaOk
2402:56:16:300PMPlasmaOk
2503:11:47:077PMPlasmaOk
2603:29:38:740PMPlasmaOk
2703:42:16:727PMPlasmaOk
2803:55:26:410PMPlasmaOk
2904:09:42:577PMPlasmaOk
3004:23:23:650PMPlasmaOk
3104:40:19:473PMPlasmaOk
3204:54:49:827PMPlasmaOk