Alcator C-Mod Run 950309 Information

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Miniproposals
Miniproposal:071
Date Filed:12/29/1994
Title:Comparison of NINJA Fueling Locations and Puffing Rates in Identical Plasmas
First Author:D Jablonski
Session Leader:D Jablonski (shots 1-39)

Operators
Session leader(s):D Jablonski
Physics operator(s):John Goetz
Engineering operator(s):Vinny Bertolino,Joe Daigle

Engineering Operator Run Comment
goetz run

Session Leader Plans

Physics Operators Plans

Session Leader Summaries
Entered: Jul 7 2004 03:49:12:523PM
Author: To Be Determined
Run 950309 was the second attempt at completing Miniproposal 71B. The attempt
was much more succesfull than the first. A large quantity of very interesting,
and very useful, data was obtained.

Preliminary analysis of the data drives one to three conclusions:

(a) There is little or no difference in the effect of puffing in different
poloidal and toroidal locations on central plasma parameters or edge density
and temperature profiles.

(b) There is little or no difference in the effect of puffing in different
poloidal locations on edge neutral densities, but there is a huge temporal
difference in toroidally specific neutral densities for different toroidal
puffing locations. (i.e. There is a much different time history of a neutral
gauge at B-port for a puff at B-port compared to a puff at F-port.)

(c) Impurity puffing (in the case of this run, of methane) shows up as highly
directional plumes emanating from the puffing locations, indicative of strong
flows at the edge. D2 fueling also usually gives rise to highly directional
plumes, implying that CX or elastic collisions may be causing significant
atomic flows of the injected deuterium.

A play by play is given below:

SHOT 1-6: Began with 950308011 with the density feedback set to 6e19, with
shot 6, a satisfactory shot was found.

SHOT 7: Copied the feedback from shot 6 into piezo preprogramming. Puffed
through B26-019 (Private Flux region on the shelf), for a .1s pulse beginning
at .45s (gas reaching plasma beginning about .53 or so) at a plenum pressure of
about 930 torr.

SHOT 8: Ran shot 7 without the NINJA puff.

SHOT 9: Decided density on shot 8 was too low. Constructed new 'basis shot'
with the density feedback engaged at 6e19 until .5s, after which preprogramming
is used. Used this piezo scheme for rest of run.

SHOT 10: Puffed at B31-038 (outboard common flux under divertor nose).

SHOT 11: Puffed at B33-001 (outboard common flux a bit beyond end of tiles).

SHOT 12: Reran basis shot without NINJA puffing.

SHOT 13: Puffed at B16-001 (inner wall midplane). A-side camera shows
circular non directional plume at puff location.

SHOT 14: Puffed at B22-022 (inboard common flux on bridge of divertor nose).
A-side camera shows directional plume at puff location.

SHOT 15: Puffed at B30-012 (private flux on floor).

SHOT 16: Puffed at F30-012 (same location as 15, but at F-port rather than
B-port).

SHOT 17: Reran baseline (no puff), got disruption at about .8s.

SHOT 18: Reran baseline.

SHOT 19: Puffed at B,D,F,H, and K30-012 simultaneously. Disrupted at about
.9s.

SHOT 20: Increased plenum pressure to about 1800 torr. Puffed at B26-019,
got a fizzle.

SHOT 21: Puffed again at B26-019.

SHOT 22: Puffed at B16-001. See directional plume on A-side camera.

SHOT 23: Puffed at B31-038. See plume on B-top camera. Cannot see well
enough to make accurate diagnosis.

SHOT 24: Puffed at B33-001. Fizzle.

SHOT 25: Puffed at B33-001.

SHOT 26: Puffed at B22-022. See directional plume on A-side camera.

SHOT 27: No Puff (rerun of baseline).

SHOT 28: No Puff (rerun of baseline).

SHOT 29-30:Puffing at B30-012. Disruption at .5s and a fizzle.

SHOT 31: Puffed at B30-012.

SHOT 32: Puffed at F30-012.

SHOT 33: Puffed at B16-001 and B22-022 simultaneously. See directional plume
(through B16-001) on A-side camera. Huge marfing activity in divertor. Record
steady state divertor pressure (about 58 mtorr), near record central density
(nl04 of about 3.7e20).

SHOT 34-35:Lowered plenum pressure to about 160 torr. Puffed at B,D,F,H, and
K30-012 simultaneously. Got a disruption at about .55s and a fizzle.

SHOT 36: Puffed at B,D,F,H, and K30-012 simultaneously.

SHOT 37: Filled plenum with about 130 torr of Methane. Changed starting time
of puff to .35s. Puffed at B16-001, B22-022 and B26-019 simultaneously. Got
disruption at about .5s.

SHOT 38: Puffed at B16-001, B22-022 and B26-019 simultaneously. Saw two
directional plumes (from B16 and B22) on A-side camera.

SHOT 39: Performed shot without plasma (or NINJA puffing) to get baseline on
quantity of gas puffed through piezo.

Physics Operator Summaries
Entered: Jul 7 2004 04:36:53:490PM
Author: To Be Determined
Physics operator summary for 950309

EO: Bertolino/Daigle
PO: Goetz
SL: Jablonski

Run 950309 was in support of Mini-Proposal #071B - Comparison of NINJA Fueling
Locations and Puffing Rates in Identical Plasmas. The goals of this
mini-proposal are 1) to investigate the variation in the effect of deuterium
puffing from different capillary locations on such parameters as fueling
efficiency, central electron density, edge electron density and temperature,
and edge neutral pressure and 2) to determine the effects of different puffing
locations on the onset of the divertor regimes.

Program for this run:
- Setup a lower SN discharge with Bt=5.3T, Ip=0.85MA, and NL_04=0.6e20
and with good gaps.
- Copy NL_04 M_OUT into PG3 voltage programming and turn off feedback.
- Vary puffing location and plenum driving pressure (and maybe gas
to helium).

This program was completely carried out, although there were some modifications
to the run plan as the run neared its end. See the Session Leader's summary
to find out the details of the physics aspects of the run.

Some random neural firings from today:
Field nulls today were not the best (compared to 950307) but most
current rises looked o.k. Therefore only tweaks to the
OH1 voltage after commutation were performed. IF more attention
should have lavished on this problem, then maybe the fizzles
late in the run wouldn't have ocurred.
Disruptions during rampdown seemed to be solved by ramping CLEARIN
hard negative and moving the x-points in.
Hard disruptions during the shot were followed by high CII levels
it seemed - and fizzles seemed to follow.
Raising the prefill throughout the day ala' ESM kept down the
hards and most current rises looked o.k.
Current rise hesitations correlated with enhanced CII light
Are the large moly injections that occur during some shots due to
the divertor gas puffs pushing moly into the plasma?

Engineering, computing, and diagnostics today: Engineering EF1L single phased
twice today, with both leading to disruptions. One was early and
the shot was wasted, but the other was an acceptable shot. Trouble
cooling two TF arms slowed down the shot cycle. Computers behaved
well today and data acquisition was quick. Diagnostics performed well.

Scorecard: 39 shots = 30 plasmas + 8 fizzles + 1 gas test

Shot summary for Run 950308
coldstart hybrid - all matrices respond
2 hours of D2 ECDC prior to the run
Load shot 950308011
NL_04 = 0.6e20 until 1.0 sec
P_0 = 2.0e-5

Shot change result
____ _____ ______
1 see above plasma - disr. @ 1.38
gaps o.k.; good target

2 cut M_OUT_14 into PG3 voltage program fizzle - not much of a null
turn off NL_04 feedback
slow down CLEARIN ramp at end of shotOH

3 P_0=2.2e-5 plasma - disr. @ 1.09
gaps o.k.; good target
NL_04=0.45e20

4 add some volts to PG3; P_o=2.4e-5 fizzle - Br too positive?
faster CLEARIN ramp at end of shot Halpha burns out, but no current

5 P_0=2.2e-5; P_NL04=4; BR_0=5.5e-3 fizzle - radial field too
negative and vertical field
coming in too quickly

6 BR_0=6.0e-3; V_OH1 raised by 20V plasma - disr. @ 1.35; good
between .005 & .015sec target plasma; NL_04=0.65e20

7 M_OUT_14 to PG3 voltage; turn off plasma - disr. @ 1.12
NL_04 feedback density >1e20

8 lower gains on ZCUR(2) during rampdown plasma - disr. @ 1.46
NL_04=1e20

9 P gain on NL_04 = 4 plasma - disr. @ 1.47
NL_04=0.65e20; good target

10 M_OUT_14 into PG3 voltage and turn plasma - disr. @ 1.45
off NL_04 feedback @ 0.5 gaps and SEPs constant

11 no changes plasma - disr. @ 1.46
gaps and SEPs constant and o.k.

12 no changes plasma - disr. @ 1.48
gaps and SEPs o.k.; NL_04=0.6e20

13 no changes plasma - disr.@1.5; good target
NL_04=0.7e20 before puff

14 no changes plasma - disr. @ 1.5
hards dump @ 0.14sec

15 P_0=2.3e-5 plasma - disr. @ 1.45 (<0.1MA)

16 ramp CLEARIN more quickly at end plasma - disr. @ 1.43

17 no gas puff; A_SIDE=18.5PSIA plasma - disr. @ 0.64; EF1L
single phases @ 0 & dies @ ~0.6

18 slow down density ramp-up and D gain plasma - disr. @ 1.12; low
on NL_04 = 1.5 density at the end of the shot

19 no spike @ 1sec on V_PG3; P_0=2.4e-5 plasma - disr. @ 0.94; EF1L
dead @ 0.89; good shot though

20 divertor plenum = 36.8PSIA fizzle - fields as good as usual
small bounce; CII light up

21 no changes plasma - all the way down
detachment soon after div. puff

22 no changes plasma - disr. @ 1.41

23 no changes plasma - disr. @ 1.41

24 P_0=2.5e-5 fizzle - fields as usual
small bounce; CII light up

25 P_0=2.4e-5 plasma - disr. @ 1.41
no current rise hesitation

26 no changes plasma - disr. @ 1.41
moly injection @ 0.86

27 add puff @ 1sec on V_PG3 plasma - disr. @ 1.45
NL_04=0.53->0.59e20

28 add puff @ 1sec on V_PG3 plasma - disr. @ 1.45
no divertor gas puff - PLC error

29 no changes plasma - disr. @ 0.48
large moly injection killed it

30 no changes fizzle - CII doesn't burn out

31 no changes plasma - disr. @ 1.41

32 no changes plasma - disr. @ 1.41

33 no changes plasma - disr. @ 1.02
too much MARFE?!?!

34 divertor plenum = 2.95PSIA; put puff plasma - disr. @ 0.57
back @ 1sec on V_PG3 large moly injection death

35 no changes fizzle - fields as usual
CII light doesn't burn out

36 no changes plasma - disr. @ 1.44
3 Mo injections during shot

37 fill divertor plenum with 3.4PSIA CH4 fizzle - a bouncer - current
rise is slow; vertical field
in too quickly

38 raise V_OH1 increased by 20V between plasma - disr. @ 1.44
.005 & .015sec methane visible on TV

39 disable power supplies and fizzle detector; copy M_OUT_14 from
950309038 in V_PG3 and turn off NL_04 feedback

Session Leader Comments
Mar 9 1995 08:41:59:780AM950309001D JablonskiUsed 950308011 with nl04 set to 6e19 on feedback. Came off great.

Mar 9 1995 08:51:47:580AM950309002D JablonskiCopied piezo programming from shot 1. Got fiz.

Mar 9 1995 09:10:15:020AM950309003D JablonskiLike shot 2, with change in prefill. Went, though disrupted at about
1.1, and the density is a bit low for comfort. We'll try to raise
density a bit before settling on basis.

Mar 9 1995 09:45:11:650AM950309006D JablonskiShot went well. Used feedback. After density is copied over, will use
as basis.

Mar 9 1995 09:55:45:520AM950309007D JablonskiPuffed through B26-019 (PFR/17) for .1 s. beginning at .45s with plenum
pressure of about 930 torr. Used copied feedback from shot 6. Ace of
a shot, can well see the D2 going into the central plasma.

Mar 9 1995 10:16:13:790AM950309007D JablonskiMeant to be basis shot. Same as 6 without NINJA. Density is all over
the place. 6 and 7 will probably be written off as useless.

Mar 9 1995 10:16:43:880AM950309008D JablonskiMeant to be basis shot. Same as 6 without NINJA. Density is all over
the place. 6 and 7 will probably be written off as useless.

Mar 9 1995 10:17:15:820AM950309008D JablonskiMeant to be basis shot. Same as 7 without NINJA. Density is all over
the place. 8 and 7 will probably be written off as useless. Disregard
the last two entries.

Physics Operator Comments
Mar 9 1995 07:48:40:020AMJohn GoetzRun 950309 - MiniProposal 071B - Comparison of NINJA Fueling Locations
and Puffing Rates in Identical Plasmas

1. Begin with shot 950308011 and NL_04 = 0.6e20

2. When shot is acceptable, copy gas valve signal into PULSE_GAS_3
voltage programming and turn off feedback.

3. Use various plenum pressures and various valve locations to puff
deuterium (and possibly helium) into the plasma beginning at
0.45sec.


Coldstart hybrid - all matrices respond

Mar 9 1995 08:46:32:340AM950309001John GoetzShot 950309001:
Load 950308011
NL_04 = 0.6e20
P_0 = 2.0e-5

Results:
Plasma - disrupts @ 1.38
i.gap=2; o.gap=2. DSEP=2; SSEP=1.6

Mar 9 1995 09:10:06:390AM950309002John GoetzShot 950309002:
slow down CLEARIN ramp (to try and stop disruption)
cut M_OUT_14 (which is PG3) into PG3 voltage programming and
turn off NL_04 feedback

Results:
fizzle - not much of a null, but it looks just like shots
that went.
plasma took a bounce

Mar 9 1995 09:11:10:990AM950309003John GoetzShot 950309003:
P_0 = 2.2e-5

Results:
plasma - disrupts @ 1.09
gaps look good - stable target for the FSP
density low though - NL_04 = 0.45e20

Mar 9 1995 09:25:09:550AM950309004John GoetzShot 950309004:
P_0 = 2.4e-5
more V on PG3 to bring up density
make CLEARIN ramp faster at the end of the shot

Results:
fizzle - burned out Halpha, but no current rise
Br a little too positive?

Mar 9 1995 09:35:56:580AM950309005John GoetzShot 950309005:
P_0 = 2.2e-5
turn on NL_04 feedback (P=4)
BR_0=5.5e-3

Results:
Fizzle - bad radial field
Bounces - vertical field coming in too quickly

Mar 9 1995 09:46:00:700AM950309006John GoetzShot 950309006:
BR_0=6.0e-3
V_OH1 raised by 20V between .005 and .015sec

Results:
Plasma - disr. @ 1.35
gaps and SEPs o.k. - stable target for FSP
NL_04 = 0.65e20

Mar 9 1995 10:17:38:750AM950309007John GoetzShot 950309007:
cut M_OUT_14 into PG3 voltage programming
turn off NL_04 feedback

Results:
plasma - disr. @ 1.12
density >1e20
divertor gas puff

Mar 9 1995 10:19:27:450AM950309008John GoetzShot 950309008:
lower gains on ZCUR(2) during rampdown
move x-points in - and ramp CLEARIN in faster during rampdown

Results:
plasma - disr. @ 1.46
NL_04=1e20

Mar 9 1995 10:47:42:950AM950309009John GoetzShot 950309009:
lower gains on ZCUR(2) during rampdown
move x-points in - and ramp CLEARIN in faster during rampdown

Results:
plasma - disr. @ 1.47
NL_04=0.65e20
good target plasma

Mar 9 1995 10:49:08:780AM950309010John GoetzShot 950309010:
M_OUT_14 into PG3 voltage and turn off NL_04 feedback at 0.5sec

Results:
plasma - disr. @ 1.45
FSP moly injection @ 0.6
gaps and SEPs constant

Mar 9 1995 11:04:07:230AM950309011John GoetzShot 950309011:
no changes

Results:
plasma - disr. @ 1.46
gaps and SEPs are o.k.

Mar 9 1995 11:19:38:030AM950309012John GoetzShot 950309012:
no changes

Results:
plasma - disr. @ 1.48
NL_04 = 0.6e20 (baseline shot)

Mar 9 1995 11:33:58:260AM950309013John GoetzShot 950309013:
make CLEARIN ramp more negative (n/ncrit getting large)

Results:
plasma - disrupts @ 1.5
NL_04 = 0.7e20 before puff

Mar 9 1995 11:56:15:200AM950309014John GoetzShot 950309014:
make CLEARIN ramp more negative
(n/ncrit doesn't get as large until later, compared to 012)

Results:
plasma - disr. @ 1.5
hard x-rays @ 0.14sec
interesting flow pattern seen on plasma TV

Mar 9 1995 12:07:16:450PM950309015John GoetzShot 950309015:
P_0=2.3e-5

Results:
plasma - disr. @ 1.45 - less than 0.1MA
o.k target plasma

Mar 9 1995 12:25:19:620PM950309016John GoetzShot 950309016:
ramp CLEARIN more quickly at end of shot

Results:
plasma - disr. @ 1.43
good target plasma

Mar 9 1995 12:33:39:670PM950309017John GoetzShot 950309017:
A_SIDE plenum pressure = 18.5PSIA
no gas puff (baseline)

Results:
plasma - disr. @ 0.64
EF1L single phases after commutation and finally dies at ~0.6sec

Mar 9 1995 12:43:01:660PM950309018John GoetzShot 950309018:
slow down initial density ramp and D gain on NL_04 = 1.5

Results:
plasma - disr. @ 1.12
low density at the end of this shot - preprogrammed voltage
not enough to hold up the density

Mar 9 1995 01:04:09:140PM950309019John GoetzShot 950309019:
remove spike @ 1sec on V_PG3
puff 5 capillaries at once

Results:
plasma - disr. @ 0.94
EF1L dead at 0.89sec
shot is acceptable though - nice target
NL-04->1.5e20

Mar 9 1995 01:17:47:100PM950309020John GoetzShot 950309020:
divertor plenum pressure = 36.8PSIA

Results:
fizzle - fields are as good or bad as usual
slight bounce
carbon signal is up a bit

Mar 9 1995 01:27:36:230PM950309021John GoetzShot 950309021:
no changes

Results:
plasma - all the way down
multiple moly injections when at low density
detaches soon after divertor puff

Mar 9 1995 01:37:28:650PM950309022John GoetzShot 950309022:
no changes

Results:
plasma - disr. @ 1.41
good target plasma
evidence of flow from midplane (in D2!, or is it carbon from
the wall)

Mar 9 1995 01:57:01:110PM950309023John GoetzShot 950309023:
no changes

Results:
plasma - disr. @ 1.41
good target plasma

Mar 9 1995 02:09:21:880PM950309024John GoetzShot 950309024:
P_0 = 2.5e-5

Results:
fizzle - fields as usual - slight bounce

Mar 9 1995 02:22:31:210PM950309025John GoetzShot 950309025:
P_0 = 2.4e-5

Results:
plasma - disr. @ 1.41
no hesitation on current rise
good target plasma

Mar 9 1995 02:35:40:170PM950309026John GoetzShot 950309026:
no changes

Results:
plasma - disr. @ 1.41
good target plasma
moly injection @ 0.86

Mar 9 1995 02:53:49:480PM950309027John GoetzShot 950309027:
add puff @ 1sec on V_PG3 (baseline shot)

Results:
plasma - disr. @ 1.45
NL_04=0.53->0.59e20; good baseline

Mar 9 1995 03:02:34:980PM950309028John GoetzShot 950309028:
remove puff @ 1sec on V_PG3

Results:
plasma - disr. @ 1.45
no divertor gas puff due to PLC error

Mar 9 1995 03:26:09:710PM950309029John GoetzShot 950309029:
no changes

Results:
plasma - disr @ 0.48
large moly injection killed this one

Mar 9 1995 03:32:56:680PM950309030John GoetzShot 950309030:
no changes

Results:
fizzle - no bounce - make it to .03MA before current stops
CII light never burns out

Mar 9 1995 03:41:52:640PM950309031John GoetzShot 950309031:
no changes

Results:
plasma - disr. @ 1.41
good target; good puff

Mar 9 1995 03:52:23:770PM950309032John GoetzShot 950309032:
no changes

Results:
plasma - disr. @ 1.41
slight hesitation on the current rise
good target

Mar 9 1995 04:05:01:690PM950309033John GoetzShot 950309033:
no changes

Results:
plasma - disr. @ 1.02
too much MARFE?!! puffed with two inner wall capillaries

Mar 9 1995 04:20:48:380PM950309034John GoetzShot 950309034:
pressure in divertor plenum = 2.95PSIA
put puff @ 1sec on V_PG3

Results:
plasma - disr. @ 0.57
done in by a large molybdenum injection

Mar 9 1995 04:28:16:630PM950309035John GoetzShot 950309035:
no changes

Results:
fizzle - fields as usual
CII light doesn't burn out
this was predicted based on the previous Mo induced disruption
behavior

Mar 9 1995 04:37:46:240PM950309036John GoetzShot 950309036:
no changes

Results:
plasma - disr. @ 1.44
three moly injections throughout the shot
divertor gas puff doesn't raise the density

Mar 9 1995 04:49:41:820PM950309037John GoetzShot 950309037:
fill divertor plenum with 3.4PSIA of CH4

Results:
fizzle - a bouncer - current rises too slowly and
the vertical field comes in too quickly

Mar 9 1995 04:59:36:320PM950309038John GoetzShot 950309038:
raise V_OH1 by 20V between .005 & .015sec

Results:
plasma - disr. @ 1.44
methane is quite visible on TV (and *CX)
acceptable target plasma

Mar 9 1995 05:07:02:000PM950309039John GoetzShot 950309039:
no power supplies
disable fizzle detector
copy M_OUT_14 from 950309038 in V_PG3 and turn off NL_04 feedback

Results:
gas puffed into the machine

Engineering Operator Comments
ShotTimeTypeStatusComment
108:31:16:960AMPlasmaOkno faults
208:46:45:930AMPlasmaOkno faults
308:56:21:300AMPlasmaOkno faults
409:15:37:760AMPlasmaOkno faults
509:26:07:200AMPlasmaOkno faults
609:36:24:560AMPlasmaOkdisruption induced comm faults
709:47:34:890AMPlasmaOkdisruption induced comm faults
810:07:19:550AMPlasmaOkno faults
910:25:09:650AMPlasmaOkno faults
1010:35:42:860AMPlasmaOkno faults
1110:54:29:570AMPlasmaOkno faults
1211:10:57:170AMPlasmaOkno faults
1311:24:32:470AMPlasmaOkno faults
1411:41:16:560AMPlasmaOkno faults
1511:55:25:250AMPlasmaOkno faults
1612:11:50:960PMPlasmaOkno faults
1712:26:40:630PMPlasmaBadef1l comm fault early
1812:37:11:160PMPlasmaOkno faults
1912:53:04:410PMPlasmaBadef1l comm fault
2001:09:12:850PMPlasmaOkno faults
2101:18:58:490PMPlasmaOkno faults
2201:28:59:510PMPlasmaOkNo Faults.
2301:49:20:920PMPlasmaOkNo Faults.
2402:03:48:820PMPlasmaOkno faults
2502:13:00:060PMPlasmaOkno faults
2602:27:46:140PMPlasmaOkNo Faults.
2702:43:00:150PMPlasmaOkNo Faults.
2802:57:56:330PMPlasmaOkNo Faults.
2903:15:24:060PMPlasmaOkComm Fault OH2U&L
3003:26:03:670PMPlasmaOkNo Faults.
3103:35:02:040PMPlasmaOkNo Faults.
3203:44:04:230PMPlasmaOkNo Faults
3303:58:19:680PMPlasmaOkComm Fault OH2L & OH1
3404:11:48:590PMPlasmaOkNo Faults.
3504:21:23:730PMPlasmaOkNo Faults
3604:29:53:220PMPlasmaOkNo Faults.
3704:43:43:880PMPlasmaOkNo Faults.
3804:52:22:260PMPlasmaOkNo Faults
3905:01:32:330PMTestOkGAS PUFF TEST.