Alcator C-Mod Run 1031202 Information

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Miniproposals
Miniproposal:374
Date Filed:11/25/2003
Title:ITB dependence on triangularity
First Author:Catherine Fiore
Session Leader:John Rice (shots 1-29)
Session Leader:Catherine Fiore (shots 1-29)

Operators
Session leader(s):John Rice,Catherine Fiore
Physics operator(s):Jim Irby
Engineering operator(s):Bill Cochran

Engineering Operator Run Comment
MP#374 ITB dependence on triangularity SL: Fiore/Rice PO: Irby EO:Cochra

Session Leader Plans

Physics Operators Plans

Session Leader Summaries
Entered: Jul 7 2004 03:49:34:977PM
Author: Catherine Fiore

1----------------------------------------------------------------------------
1031202xxx irby PHYSICS_OPERATOR Dec 2 2003 7:32:58:333AM
. . . . . . . . . . . . . . . . . . . .
Engineering setup for Tue, 2 Dec 2003

MP#374 --- ITB dependence on triangularity

Session leader : Fiore/Rice
Physics operator: Irby

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

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

Power systems the same as on 1021010004.

A-coils should be hooked up as on 1031126028 (+Dtop -Dbot -Jtop
+Jbot), and the power supply should be enabled.

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 gatevalves (there will be no vacuum problems): ECE, VUV, DNB

-------------------------------------------------------------------------------
RF Setup: All 4 transmitters in Run On by 08:00
-------------------------------------------------------------------------------

Session Leader Run Plan:

The purpose of this experiment is to explore the influence of the
plasma triangularity on the ITB quality, and specifically to see if
obtaining an ITB is easier, and if higher densities and better
confinement can be achieved. Reproduce ITB from 1021010004 (1-5
shots)

How we proceed depends on whether we can successfully make ITBs. From
the triangularity settings of that shot, scan up in delta_lower (0.1
increments up to 0.75, 5-8 shots)

Repeat for delta_upper holding delta_lower constant.


If a good high triangularity ITB has been established, scan target
density to optimize ITB.
______________________________________________

This run was problematical. It was preceeded for most of us by a horrible
commute caused by an unexpected 1/2 inch of snow. Difficulty with some of the
computers delayed the initial shots, and the visible bremsstrahlung data was
not available until shot 5.

Overall, we had difficulty obtaining a steady EDA- Hmode at a low enough
magnetic field to form an ITB. The radiated power was high, and we had as
many as 9 back-transitions in a single shot. We did manange to make one
sustained H-mode at 5.4 T, but not at 4.5 T.

We had at most 3 ITBs, the best ITB on shot 27. While we had 3 different
triangularities, we basically did not accomplish anything on this MP.

1031202005 Shot went into EDA H-mode, but was prevented from going ITB by
repeated back transitions. The radiated power was high. We will back off
on the rf power


1031202006 We backed off too much on the rf (1.7 MW) and didn't transition
to H-mode. We will try 1.95

1031202007
We made an H-mode but it was not steady and there were multiple back
transitions. There was still too much radiated power. We will try to
increase the target density.

1031202008 No H-mode. D-port power didn't run because the target density
was higher.

1031202009 No H-mode. Density feedback is creating problems.

1031202010 No H-mode. Density and rf were on target. We will try to
increase the rf power.

1031202011 No plasma. Fizzle

1031202012 H-mode with multiple back transitions, no apparent ITB on
the longest lasting H-mode.

1031202013 Nine short H-modes, no ITB. The rf power was pretty
high, so we'll back off on that somewhat.

1031202014 Nearly identical to sot 13: Nine or 10 short H-modes, no ITB.
We'll drop the rf power a little more. If that doesn't work, we'll try
to get an EDA at higher magnetic field.

1031202015 Eight short H-modes, no ITB. We are going to try to get an
EDA at higher magnetic field.

1031202016 At higher field we are getting longer lasting H-modes, only 4
of them. ITBs are not expected at this field. The target density is a bit low
also.

1031202017 Three H-modes this time. We will try one more shot with a
little bit higher density, ITBs are not expected at this field.

1030202018 No H-mode. Density too high for J-port.

1031202019 No plasma.

1031202020 Steady H-mode for 750 ms. We will go back to lower field
and try to get an ITB

1031202021 No plasma

1031202022 The field was lowered, and once again we had 8 short H-modes.
No ITB. We will raise the current slightly.

1031202023 Five short H-modes were followed by the plasma terminating
in a disruption. Ip=0.9 MA, RF=2MW No ITB. We will try going to lower
current (0.7 MA).

1031202024 The H-mode started much later than normal (1s.) There were
three H-modes, and an ITB appeared to form on the last one. We are going
to repeat the shot.

103120225 No plasma, fizzle.

1031202026 Two H-modes, with an ITB on the second. We will try
slightly higher RF power on the next shot.

1031202027 Three H-modes. The density peaking
increased throughout the H-mode phase of the plasma, despite 2
back-transitions. This was the best ITB of the day so far.
We are actually going to try changing the triangularity for the next shot.-

1031202028 No H-mode. The plasma was probably too close to the inner wall.

1031202029 No plasma, fizzle.

Physics Operator Summaries
Entered: Jul 7 2004 04:37:19:880PM
Author: Jim Irby
Engineering setup for Tue, 2 Dec 2003

MP#374 --- ITB dependence on triangularity

Session leader : Fiore/Rice
Physics operator: Irby

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

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

Power systems the same as on 1021010004.

A-coils should be hooked up as on 1031126028 (+Dtop -Dbot -Jtop
+Jbot), and the power supply should be enabled.

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 gatevalves (there will be no vacuum problems): ECE, VUV, DNB

-------------------------------------------------------------------------------
RF Setup: All 4 transmitters in Run On by 08:00
-------------------------------------------------------------------------------

Session Leader Run Plan:

The purpose of this experiment is to explore the influence of the
plasma triangularity on the ITB quality, and specifically to see if
obtaining an ITB is easier, and if higher densities and better
confinement can be achieved. Reproduce ITB from 1021010004 (1-5
shots)

How we proceed depends on whether we can successfully make ITBs. From
the triangularity settings of that shot, scan up in delta_lower (0.1
increments up to 0.75, 5-8 shots)

Repeat for delta_upper holding delta_lower constant.


If a good high triangularity ITB has been established, scan target
density to optimize ITB.

----------------------------------------------------------------------------
Summary
----------------------------------------------------------------------------

The machine ran pretty well today, but it was very difficult to
produce eda plasmas. Boronization is probably no longer adequate.
Entry into h-mode resulted in radiated power approximately a factor of
three larger than in the 1021010 run. We mostly produced multiple
elm-free periods w/o ITGs at the lower TF fields of 4.5 T. When we
went back up to 5.4T and 3 MW of rf power on shot 16 we produced fewer
h-modes, but still no extended period of eda. After an increase in
target density and a reduction in rf power to 2 MW we finally got an
extended eda period on shot 20. The radiated power was very low and
similar to the 1021010 run.

Dropping back down to 4.5T we again had many h-mode periods. When we
dropped Ip to 700 kA we got fewer h-modes and the last one actually
had a ITB. The remaining shots of the day only resulted in a couple
of additional poor ITBs. An attempt at higher triangularity resulted
in delta of 0.65, but light on the inner wall, and no h-modes.


problems:

We started out with a plasma but immediately found that most of the
analysis routines were not running (no efit for example). This
problem was traced to the workstations not communicating through the
gigabit switch. Henry thought he had freed everything up for shot 03,
but routines continued to fail and workstations that were working
would often grind to a halt (no efit again for shot 03). I tried to
run efit by hand but still no efit and no error messages. This problem
was solved by shot 4. Steve Wolfe was able to recover efit for shots
2 and 3.

score:

Fizzles 11,19,21,25,29

Plasmas 02,03,04,05,06,07,08,09,10,12,
13,14,15,16,17,18,20,22,23,24,
26,27,28

Tests 01

Session Leader Comments
Dec 2 2003 11:27:24:857AM1031202005Catherine FioreShot went into EDA H-mode, but was prevented from going ITB by repeated back
transitions. The radiated power was high. We will back off on the rf power
Dec 2 2003 11:30:37:733AM1031202006Catherine FioreWe backed off too much on the rf (1.7 MW) and didn't transition to H-mode. We will try 1.95
Dec 2 2003 11:55:44:550AM1031202007Catherine FioreWe made an H-mode but it was not steady and there were multiple back transitions.
There was still too much radiated power. We will try to increase the target density.
Dec 2 2003 12:08:05:280PM1031202008Catherine FioreNo H-mode. D-port power didn't run because the target density was higher.
Dec 2 2003 12:27:21:637PM1031202009Catherine FioreNo H-mode. Density feedback is creating problems.
Dec 2 2003 12:41:59:163PM1031202010Catherine FioreNo H-mode. Density and rf were on target. We will try to increase the rf power.
Dec 2 2003 12:51:07:060PM1031202011Catherine FioreNo plasma. Fizzle
Dec 2 2003 01:10:12:763PM1031202012Catherine FioreH-mode with multiple back transitions, no apparent ITB on the longest lasting H-mode.
Dec 2 2003 01:29:50:793PM1031202013Catherine FioreNine short H-modes, no ITB. The rf power was pretty
high, so we'll back off on that somewhat.
Dec 2 2003 01:40:41:850PM1031202014Catherine FioreNearly identical to sot 13: Nine or 10 short H-modes, no ITB. We'll drop the rf
power a little more. If that doesn't work, we'll try to get an EDA at higher
magnetic field.
Dec 2 2003 01:52:52:907PM1031202015Catherine FioreEight short H-modes, no ITB. We are going to try to get an EDA at higher magnetic field.
Dec 2 2003 02:22:34:417PM1031202016Catherine FioreAt higher field we are getting longer lasting H-modes, only 4 of them. ITBs are not
expected at this field. The target density is a bit low.
Dec 2 2003 02:21:48:027PM1031202017Catherine FioreThree H-modes this time. We will try one more shot with a little bit higher density, ITBs are not
expected at this field.
Dec 2 2003 02:55:38:073PM1031202019Catherine FioreNo plasma.
Dec 2 2003 03:04:11:213PM1031202020Catherine FioreSteady H-mode for 750 ms. We will go back to lower field and try to get an ITB
Dec 2 2003 03:13:24:323PM1031202021Catherine FioreNo plasma
Dec 2 2003 03:30:24:573PM1031202022Catherine FioreThe field was lowered, and once again we had 8 short H-modes. No ITB.
We will raise the current slightly.
Dec 2 2003 03:41:23:073PM1031202023Catherine FioreFive short H-modes were followed by the plasma terminating in a disruption. Ip=0.9 MA, RF=2MW No ITB.
We will try going to lower current (0.7 MA).
Dec 2 2003 04:03:06:667PM1031202024Catherine FioreThe H-mode started much later than normal (1s.) There were three H-modes,
and an ITB appeared to form on the last one. We are going to repeat the shot.
Dec 2 2003 04:11:34:400PM1031202025Catherine FioreNo plasma, fizzle.
Dec 2 2003 04:29:31:557PM1031202026Catherine FioreTwo H-modes, with an ITB on the second. We will try slightly higher RF power on the next shot.
Dec 2 2003 04:43:21:807PM1031202027Catherine FioreThree H-modes. The density peaking
increased throughout the H-mode phase of the plasma, despite 2 back-transitions.
This was the best ITB of the day so far.
We are actually going to try changing the triangularity for the next shot.
Dec 2 2003 04:53:01:917PM1031202028Catherine FioreNo H-mode. The plasma was probably too close to the inner wall.
Dec 2 2003 05:02:38:150PM1031202029Catherine FioreNo plasma.

Physics Operator Comments
Dec 2 2003 07:32:58:333AMJim IrbyEngineering setup for Tue, 2 Dec 2003

MP#374 --- ITB dependence on triangularity

Session leader : Fiore/Rice
Physics operator: Irby

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

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

Power systems the same as on 1021010004.

A-coils should be hooked up as on 1031126028 (+Dtop -Dbot -Jtop
+Jbot), and the power supply should be enabled.

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 gatevalves (there will be no vacuum problems): ECE, VUV, DNB

-------------------------------------------------------------------------------
RF Setup: All 4 transmitters in Run On by 08:00
-------------------------------------------------------------------------------

Session Leader Run Plan:

The purpose of this experiment is to explore the influence of the
plasma triangularity on the ITB quality, and specifically to see if
obtaining an ITB is easier, and if higher densities and better
confinement can be achieved. Reproduce ITB from 1021010004 (1-5
shots)

How we proceed depends on whether we can successfully make ITBs. From
the triangularity settings of that shot, scan up in delta_lower (0.1
increments up to 0.75, 5-8 shots)

Repeat for delta_upper holding delta_lower constant.


If a good high triangularity ITB has been established, scan target
density to optimize ITB.
Dec 2 2003 08:04:34:653AMJim IrbyLoaded seg2 from 1021010004 into seg2 --- 0.8 MA, SN, Bt ramp to 4.52 T

did load/clean

Dec 2 2003 08:19:06:230AM1031202001Jim IrbyCycle test with gas --- data system seems okay --- gas and ratiomatic operational
Dec 2 2003 09:45:38:810AM1031202002Jim IrbyPlasma attempt

ECDC in D2 was run overnight --- 60C bake

EF4 at -1330
Gas puff 15 ms
nl04 request at 8.5e19/m^2


Plasma into rampdown --- multiple elm-free h-modes, but rf power low and irratic

current rise good, but breakdown pretty late

density/current/Btor programming looks good --- very close to 1021010004

no efit data --- many workstations down on otherside of gigabit switch

did not program a-coils --- should be set for next shot
Dec 2 2003 10:40:31:993AM1031202003Jim Irbyrepeat PCS

plasma --- no h-modes --- only 0.6 MW from D

lockup again on computers

Steve Wolfe ran efit for shots 2 an 3
Dec 2 2003 10:56:31:003AM1031202004Jim IrbyPCS repeat


plasma into rampdown --- multiple h-modes --- pretty clean 1.2 MW of ICRF --- no e-port

computers still very slow

Dec 2 2003 11:21:15:163AM1031202005Jim Irbyplasma into rampdown --- elm-free periods

h/(h+d) about 5%

radiated power (2 pi diode) much higher than 1021010 run during rf
Dec 2 2003 11:35:14:830AM1031202006Jim IrbyNo PCS changes

Asked Yijun to provide power from d and e only as in 1021010 run

plasma to 1.87 s --- too little power for h-mode, but very nice clean pulse at 1.8 MW

next shot a little more power --- 1.95 MW request

Dec 2 2003 11:56:24:550AM1031202007Jim IrbyICRF request to 1.95 MW
No PCS changes
Waited for basepressure to reach 4e-6 Torr --- took 18 minutes

plasma into rampdown --- returned to multiple h-mode operation --- radiation about the same as shot 5

h/(h+d) about 5%

Dec 2 2003 12:15:39:817PM1031202008Jim Irbynl04 request to 9.5e19 from 8.5e19/m^2

disruption --- lost HeNe #2 and density feedback

density change limited rf --- a little tuning needed

Dec 2 2003 12:38:36:583PM1031202009Jim IrbyNo PCS changes

took shot starting at 4e-6 Torr, abt 18 minutes --- help recovery from disruption

plasma into rampdown but still lost hene 2

bad tune for rf
Dec 2 2003 12:47:44:543PM1031202010Jim IrbyNo PCS changes

plasma into rampdown, but no h-modes --- raise power again next shot

TCI solid again


Dec 2 2003 12:52:43:140PM1031202011Jim Irbyfizzle

gas and fields look very good --- will just try again

Dec 2 2003 01:14:28:017PM1031202012Jim Irbyplasma into rampdown --- got requested density, but still multiple h-modes

Dec 2 2003 01:30:49:357PM1031202013Jim IrbyRXL from +0.015 to 0.00

start pressue is 5e-6 Torr --- will open pumpstack 1 to system before next shot

plasma into rampdown --- many h-modes

triangularity up from 4.5 to 5.5 as expected

2 pi signal about a factor of three higher than 1021010004. rf power 3.5 MW now vs 2 MW then.

Catherine asking for 2.5 MW next shot
Dec 2 2003 01:38:42:957PM1031202014Jim Irbyless rf power requested

pumpstack 1 is now open

plasma into rampdown with many h-modes again --- less rf power, but still very similar to last shot

Dec 2 2003 01:52:07:750PM1031202015Jim Irbyreduce rf power one more time to 2.0 MW

reduced argon puff to 20 ms from 40 ms

plasma into rampdown --- still many h-modes

next shot back to 5.4 T and 3 MW
Dec 2 2003 02:10:42:307PM1031202016Jim IrbyTF back to 5.4 T
ICRF request to 3 MW

plasma into rampdown --- fewer h-modes, but no extended eda period

solid 3 MW of rf

did not make density request --- next shot 1e20
Dec 2 2003 02:30:32:150PM1031202017Jim Irbydensity request to 1e20 from 9.5e19 /m^2 --- also started density rise sooner

plasma into rampdown --- target density nearly 1e20 /m^2 --- only 3 h-mode periods instead of 4.

W about 90 kJ

Dec 2 2003 02:37:40:713PM1031202018Jim Irbynl04 request 1.2e20/m^2

plasma into rampdown --- density too high for j-port --- no h-modes
Dec 2 2003 02:47:39:543PM1031202019Jim Irbynl04 request down to 1.1e20/m^2 --- may help j-port --- should be able to improve d-port

argon back to 40 ms


fizzle --- fields look good. gas maybe a little low
Dec 2 2003 03:04:05:293PM1031202020Jim Irbygas puff from 15 to 17 ms

plasma into rampdown --- extended eda this time I think --- no j-port, only about 2 MW total
Dec 2 2003 03:17:07:963PM1031202021Jim Irbyramped field back down to 4.5 T (126 kA)
dropped nl04 request to 1e20/m^2


fizzle --- carbon II spike at 10 ms --- bounce

Dec 2 2003 03:29:30:417PM1031202022Jim Irbyplasma into rampdown --- 3 MW of clean rf, but 8 h-mode periods

Dec 2 2003 03:41:49:497PM1031202023Jim IrbyPlasma current to 900 kA from 800 kA

turn off j-port --- keep us at 2 MW

disruption at 1.3 s
Dec 2 2003 04:02:13:997PM1031202024Jim IrbyIp to 700 kA

plasma into rampdown --- 3 h-modes starting at 900 ms

3rd h-mode had an ITB

2.1 MW of rf


Dec 2 2003 04:20:01:620PM1031202025Jim Irbyrepeat --- no PCS or rf changes

fizzle --- again no clear reason --- higher CII as seen earlier


Dec 2 2003 04:31:30:777PM1031202026Jim Irbytry again --- no changes

plasma into rampdown --- 2 h-modes, 2nd one with ITB

Dec 2 2003 04:40:36:400PM1031202027Jim Irbyadd a little more rf --- earlier h-mode?

plasma into rampdown --- h-modes now start earlier --- 3 h-modes instead of 2

probable ITB on number 3
Dec 2 2003 04:58:25:870PM1031202028Jim IrbyRXL to -0.015 from 0.00 --- increase triangularity
reduced gas puff from 17 to 16 ms

plasma into rampdown --- no h-modes --- light on inner wall

triangularity 0.65 or better

Engineering Operator Comments
ShotTimeTypeStatusComment
108:07:28:780AMTestOk
209:01:58:433AMPlasmaOk
309:45:43:530AMPlasmaOk
410:39:49:913AMPlasmaOk
511:01:27:837AMPlasmaOk
611:19:28:930AMPlasmaOk
711:40:42:163AMPlasmaOk
811:59:48:117AMPlasmaOk
912:20:30:070PMPlasmaOk
1012:35:07:767PMPlasmaOk
1112:48:17:043PMPlasmaOk
1201:01:38:633PMPlasmaOk
1301:19:24:147PMPlasmaOk
1401:32:00:060PMPlasmaOk
1501:46:51:777PMPlasmaOk
1602:00:00:990PMPlasmaOk
1702:12:26:637PMPlasmaOk
1802:29:22:807PMPlasmaOk
1902:43:12:700PMPlasmaOk
2002:55:52:620PMPlasmaOk
2103:09:26:167PMPlasmaOk
2203:21:43:463PMPlasmaOk
2303:35:43:620PMPlasmaOk
2403:54:39:137PMPlasmaOk
2504:07:07:200PMPlasmaOk
2604:19:49:920PMPlasmaOk
2704:32:22:730PMPlasmaOk
2804:46:39:620PMPlasmaOk
2905:00:00:963PMPlasmaOk