Alcator C-Mod Run 1040401 Information

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Miniproposals
Miniproposal:371
Date Filed:11/14/2003
Title:2 MA Operation on Alcator C-Mod
First Author:Jim Irby
Session Leader:Robert Granetz (shots 1-15)

Operators
Session leader(s):Robert Granetz
Physics operator(s):Bill Rowan
Engineering operator(s):Gary Dekow

Engineering Operator Run Comment
MP# 371: 2MA operation at 8T

Session Leader Plans

Physics Operators Plans

Session Leader Summaries
Entered: Jul 7 2004 03:49:04:227PM
Author: Robert Granetz
Run summary for run 1040401 (Thursday):

MP 371 -- 2 MA operation at 8 T

Session leader: R. Granetz/J. Irby
Physics operator: W. Rowan

Summary: No progress made. We only got a half-day because the NSTAR 13.8
kV line went down in the middle of the day (no doubt due to the
heavy rains and flooding we're experiencing), and all the 8 T
attempts during the morning were fizzles. This might be an effect
of last night's boronization.

-------------------------------------------------------------------------------
Run Plan: Start with a repeat of 1040331001 (1.05 MA, 5.5 T, Prf=4 MW) to
confirm that TF instrumentation is all working, and to determine
if boronization recovery is necessary. When ready, load shot
1040331006 (1.05 MA, 8.0 T) from yesterday. (Set PLC TF limit at
235 kA and TF start at t=-1.5 s). Raise Ip in 0.2 MA increments,
while also raising the A-coil current and the PLC OH/EF limits
appropriately. (Session leaders will specify the desired A-coil
current for each shot.) We want RF heating in order to help with
OH flux budget, but if it introduces lots of impurities, we may
want to rethink this.

Monitor:
(1) locked mode diagnostics
(2) halo currents and Ih*Bt product on disruptions
(3) TF, OH, and EF instrumentation

If locked modes appear, we have the option of raising the plasma
density, in addition to the A-coil current, depending on how
successful the RF is at heating the plasma.

If it is feasible to shorten the flattop, we should do it in
order to reduce magnet heating and increase the rep rate.

-------------------------------------------------------------------------------
Boronization was done overnight. No ECDC, no bake.

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

Physics Operator Summaries
Entered: Jul 7 2004 04:36:49:757PM
Author: Bill Rowan
Physop Summary for 1040401. April 1, 2004.

Purpose: MP 371: 2 MA operation at 8 T

Session leader: R. Granetz/J. Irby
Physics operator: W. Rowan

Summary
The machine was boronized last night. The first plasma attempt was a fizzle.
The following shot disrupted early possibly due to an injection. The following
four shots were at 5.4 T and all were full length.

After going to 8 T for shot 008, there were 4 fizzles. In the course of these,
parameters were first changed to closely match prefill, BR_0, and Bz_0 on shot
006 from earlier in the day. This did not work.
Changes to prefill pressure in the opposite direction and to BR_0 also produced a
fizzle.

The next change would have been to reload shot 1040401007 to return to the shot
used earlier in the day. No shots were taken since the 13.8 kV input to the
lab failed just as the shot was starting.

Score Card
Engineer test 1 001
Fizzles 5 002,008,009,010,011
Early disruption 1 003
Plasma 4 004,005,006,007
Engineering Fault 1 012

Details
Engineering setup for Thursday, 01 Apr 2004

MP 371: 2 MA operation at 8 T

Session leader: R. Granetz/J. Irby
Physics operator: W. Rowan

No ECDC overnight, since we're boronizing.

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

Power systems the same as 1040331001 (1.05 MA, 5.5 T, lower X-point)

A-coils should be configured as on 1040127010 (+Dtop -Dbot -Jtop +Jbot)

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 with 15 psi He3 Hybrid enabled (PG2)
fill C-side with 30 psi D2 Hybrid enabled (PG3)

Disable NINJA

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

Necessary diagnostics:
ECE (set for 8 tesla), TCI, halo current diagnostics, TF scanner and OH coax
resistance and thermocouple instrumentation

-------------------------------------------------------------------------------
RF Setup: All four transmitters in RUN-ON by 08:00, all at 80 MHz

-------------------------------------------------------------------------------
Run Plan: Start with a repeat of 1040331001 (1.05 MA, 5.5 T, Prf=4 MW) to
confirm that TF instrumentation is all working, and to determine
if boronization recovery is necessary. When ready, load shot
1040331006 (1.05 MA, 8.0 T) from yesterday. (Set PLC TF limit at
235 kA and TF start at t=-1.5 s). Raise Ip in 0.2 MA increments,
while also raising the A-coil current and the PLC OH/EF limits
appropriately. (Session leaders will specify the desired A-coil
current for each shot.) We want RF heating in order to help with
OH flux budget, but if it introduces lots of impurities, we may
want to rethink this.

Monitor:
(1) locked mode diagnostics
(2) halo currents and Ih*Bt product on disruptions
(3) TF, OH, and EF instrumentation

If locked modes appear, we have the option of raising the plasma
density, in addition to the A-coil current, depending on how
successful the RF is at heating the plasma.

If it is feasible to shorten the flattop, we should do it in
order to reduce magnet heating and increase the rep rate.



Boronization last night.
Load the first shot from yesterday to check the operation before starting the
high-current, high-field discharges

Loaded 1040331001.
Reduced the prefill from 15 ms to 13 ms expecting more fueling in the early
discharges after boronization


001. TF test shot at low current.

Next shot.
Disabled PG2 (b-side upper). This is He3. I am told that JT reported that
it built up shot to shot yesterday and we would prefer to have control over
the level.

Delay in the next shot due to computer problems.

002. Fizzle

Next shot. Increased the prefill by 2 ms back to 15 ms
Both BR_0 and Bz_0 are the same as on shot 1040331001.
The shot loaded had a field of 6.5T. I reduced this to 5.4 T for the next shot.

003. Plasma. Early disruption. Finally ends at 180 ms.

Next shot. Reduced IP to 0.8 MA

004. Plasma. Full length.

Next shot. Increased current demand near 0.1 s to get rid of glitch.


005. Plasma.

Next shot.
Increased the current to 1 MA.

006. Plasma. Full length.
1.0 MA
DNB gate valve did not open properly on this shot or on a couple previous.
Due to some problem in moving through states. Minor as the machine is
operating perfectly well. Josh and Tom are working on it.

Next shot.
No PCS changes.

007. Plasma. Full length.

Next shot.
Reloaded shot 1040331006.
Changed PLC TF limit to 235 kA
Changed TF start time 10 -1.5 s
Enabled PG2 (b-side upper)
Increased PG2 from 6 ms (which is the value for the shot that I loaded) to 15
ms at request of RF-folk
This shot is expected to be 8T and 1MA


008. Fizzle
BT reached 8T

Next shot.
Bz_0 is more negative on shot 008 than on 007.
Changed IC_EF4 fro, -1335 to -1325 to make Bz_0 more positive


009. Fizzle.
For this shot. The prefill is 15 ms. Pressure is 0.037 mT
For shot 006, the pressure was 0.043 mT

Next shot.
Prefill increased from 15 ms to 16 ms


010 Fizzle

Next shot.
Prefill decreased from 16 ms to 14 ms.
That is a reduction of 1 ms from shot 008.
Changed IC_EF4 -1335
Changed BR_0 to from 0 to 0.2 mT


011. Fizzle
prefill pressure is 0.031

Next shot.
Reload the last 5.4 T shot that worked today.
Reload 1040401007

012. Problem before this shot. Breakers out.

Lost the 13.8 kV input to the lab.

Session Leader Comments
Mar 31 2004 07:10:03:323PMRobert GranetzRun Plan: Start with a repeat of 1040331001 (1.05 MA, 5.5 T, Prf=4 MW) to
confirm that TF instrumentation is all working, and to determine
if boronization recovery is necessary. When ready, load shot
1040331006 (1.05 MA, 8.0 T) from yesterday. (Set PLC TF limit at
235 kA and TF start at t=-1.5 s). Raise Ip in 0.2 MA increments,
while also raising the A-coil current and the PLC OH/EF limits
appropriately. (Session leaders will specify the desired A-coil
current for each shot.) We want RF heating in order to help with
OH flux budget, but if it introduces lots of impurities, we may
want to rethink this.

Monitor:
(1) locked mode diagnostics
(2) halo currents and Ih*Bt product on disruptions
(3) TF, OH, and EF instrumentation

If locked modes appear, we have the option of raising the plasma
density, in addition to the A-coil current, depending on how
successful the RF is at heating the plasma.

If it is feasible to shorten the flattop, we should do it in
order to reduce magnet heating and increase the rep rate.
Apr 1 2004 08:04:44:507AMRobert Granetz Boronization was done overnight. No ECDC, no bake.
Apr 1 2004 04:21:30:787PMRobert GranetzRun summary for run 1040401 (Thursday):

MP 371 -- 2 MA operation at 8 T

Session leader: R. Granetz/J. Irby
Physics operator: W. Rowan

Summary: No progress made. We only got a half-day because the NSTAR 13.8
kV line went down in the middle of the day (no doubt due to the
heavy rains and flooding we're experiencing), and all the 8 T
attempts during the morning were fizzles. This might be an effect
of last night's boronization.

Physics Operator Comments
Apr 1 2004 08:08:52:030AMBill RowanEngineering setup for Thursday, 01 Apr 2004

MP 371: 2 MA operation at 8 T

Session leader: R. Granetz/J. Irby
Physics operator: W. Rowan

No ECDC overnight, since we're boronizing.

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

Power systems the same as 1040331001 (1.05 MA, 5.5 T, lower X-point)

A-coils should be configured as on 1040127010 (+Dtop -Dbot -Jtop +Jbot)

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 with 15 psi He3 Hybrid enabled (PG2)
fill C-side with 30 psi D2 Hybrid enabled (PG3)

Disable NINJA

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

Necessary diagnostics:
ECE (set for 8 tesla), TCI, halo current diagnostics, TF scanner and OH coax
resistance and thermocouple instrumentation

-------------------------------------------------------------------------------
RF Setup: All four transmitters in RUN-ON by 08:00, all at 80 MHz

-------------------------------------------------------------------------------
Run Plan: Start with a repeat of 1040331001 (1.05 MA, 5.5 T, Prf=4 MW) to
confirm that TF instrumentation is all working, and to determine
if boronization recovery is necessary. When ready, load shot
1040331006 (1.05 MA, 8.0 T) from yesterday. (Set PLC TF limit at
235 kA and TF start at t=-1.5 s). Raise Ip in 0.2 MA increments,
while also raising the A-coil current and the PLC OH/EF limits
appropriately. (Session leaders will specify the desired A-coil
current for each shot.) We want RF heating in order to help with
OH flux budget, but if it introduces lots of impurities, we may
want to rethink this.

Monitor:
(1) locked mode diagnostics
(2) halo currents and Ih*Bt product on disruptions
(3) TF, OH, and EF instrumentation

If locked modes appear, we have the option of raising the plasma
density, in addition to the A-coil current, depending on how
successful the RF is at heating the plasma.

If it is feasible to shorten the flattop, we should do it in
order to reduce magnet heating and increase the rep rate.



Boronization last night.
Apr 1 2004 08:17:37:603AMBill RowanBoronization last night.
Load the first shot from yesterday to check the operation before starting the high-current, high-field discharges

Loaded 1040331001.
Reduced the prefill from 15 ms to 13 ms expecting more fueling in the early discharges after boronization
Apr 1 2004 09:01:50:563AM1040401001Bill Rowan001. TF test shot at low current.
Apr 1 2004 09:11:18:530AM1040401001Bill Rowan001. TF test shot at low current.Next shot.
Disabled PG2 (b-side upper). This is He3.
I am told that JT reported that it built up shot to shot yesterday and
we would prefer to have control over the level.
Apr 1 2004 09:11:54:580AM1040401001Bill Rowan

Delay in the next shot due to computer problems.
Apr 1 2004 09:25:29:710AM1040401002Bill RowanBoth BR_0 and Bz_0 are the same as on shot 1040331001.
The shot loaded had a field of 6.5T. I reduced this to 5.4 T for the next shot.
Apr 1 2004 09:49:51:607AM1040401003Bill Rowan003. Plasma. Early disruption. Finally ends at 180 ms.

Next shot. Reduced IP to 0.8 MA
Apr 1 2004 10:05:47:880AM1040401004Bill Rowan004. Plasma. Full length.

Next shot. Increased current demand near 0.1 s to get rid of glitch.
Apr 1 2004 10:25:22:630AM1040401005Bill Rowan005. Plasma.

Next shot.
Increased the current to 1 MA.
Apr 1 2004 10:37:47:430AM1040401006Bill Rowan006. Plasma. Full length.
1.0 MA
DNB gate valve did not open properly on this shot or on a couple previous.
Due to some problem in moving through states. Minor as the machine is
operating perfectly well. Josh and Tom are working on it.

Next shot.
No PCS changes.
Apr 1 2004 11:05:00:973AM1040401007Bill Rowan007. Plasma. Full length.

Next shot.
Reloaded shot 1040331006.
Changed PLC TF limit to 235 kA
Changed TF start time 10 -1.5 s
Enabled PG2 (b-side upper)
Increased PG2 from 6 ms (which is the value for the shot that I loaded) to 15 ms at request of RF-folk
Apr 1 2004 11:06:12:053AM1040401007Bill Rowan
This shot is expected to be 8T and 1MA
Apr 1 2004 11:21:10:387AM1040401008Bill Rowan008. Fizzle
BT reached 8T


Next shot.
Bz_0 is more negative on shot 008 than on 007.
Changed IC_EF4 fro, -1335 to -1325 to make Bz_0 more positive
Apr 1 2004 11:49:07:133AM1040401009Bill Rowan009. Fizzle.
For this shot. The prefill is 15 ms. Pressure is 0.037 mT
For shot 006, the pressure was 0.043 mT

Next shot.
Prefill increased from 15 ms to 16 ms
Apr 1 2004 12:07:12:193PM1040401010Bill Rowan010 Fizzle

Next shot.
Prefill decreased from 16 ms to 14 ms.
That is a reduction of 1 ms from shot 008.
Changed IC_EF4 -1335
Changed BR_0 to from 0 to 0.2 mT
Apr 1 2004 01:04:45:267PM1040401012Bill Rowan011. Fizzle
prefill pressure is 0.031

Next shot.
Reload the last 5.4 T shot that worked today.
Reload 1040401007

012. Problem before this shot. Breakers out.

Lost the 13.8 kV input to the lab.


Engineering Operator Comments
ShotTimeTypeStatusComment
108:59:56:700AMTestOkTF 50kA plc test shot
209:15:10:697AMPlasmaOk
309:38:03:480AMPlasmaOk
409:55:48:913AMPlasmaOk
510:13:19:067AMPlasmaOk
610:30:21:420AMPlasmaOk
710:52:23:250AMPlasmaOk
811:08:47:103AMPlasmaOk
911:33:08:813AMPlasmaOk
1011:56:10:910AMPlasmaOk
1112:19:41:120PMPlasmaOk
1212:43:05:310PMTestOk
1304:12:16:650PMTestOk
1404:18:26:137PMTestOk
1504:27:52:837PMTestOk