Alcator C-Mod Run 1040326 Information

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Miniproposals
Miniproposal:384
Date Filed: 2/2/2004
Title:Experiments on Plasma Flows and the L-H Threshold: low density discharges, limited versus diverted t
First Author:Brian Labombard
Session Leader:Brian Labombard (shots 1-30)

Operators
Session leader(s):Brian Labombard
Physics operator(s):Jim Irby
Engineering operator(s):Bill Cochran,Ed Fitzgerald,Bill Byford,Bill Parkin,Gary Dekow

Engineering Operator Run Comment
MP384; SL:Lambombard; PO:Irby; EO:Dekow/Ftiz/Byford

Session Leader Plans

Physics Operators Plans

Session Leader Summaries
Entered: Jul 7 2004 03:49:04:180PM
Author: Brian Labombard
Run Summary for 1040326

Physics Operator: J. Irby
Session Leader: B. LaBombard
______________________________________________________________________________
Purpose:
Explore relationships between edge plasma flows, magnetic topologies,
and the L-H power threshold.

This is a continuation from 1040325, focusing on lower-limited
and lower x-point topologies.

Shot Plan:
All shots are 0.8MA, 5.4 tesla discharges.
Start: reload from Shot#1040325031 - LIMITED on inner div. nose,
running on segment#4

Note: This shot has the following setup:

Shot A - Segment#2, a SNL discharge with NORMAL inner
divertor nose gap. NL04=0.55e20

Shot B - Segment#3, a SNL discharge with SMALL inner
divertor nose gap. NL04=0.55e20

Shot C - Segment#4, a LIMITED discharge on inner divertor nose
NL04=0.55e20

Set probe scan times to 0.65, 0.85 and 1.05 seconds.
Program RF power ramp of 0.5 to 1.5 MW over time interval 0.95 to 1.5 sec.

We will be switching between Shots A,B,C most of the day.
........
Part C. Effect of inner divertor nose recycling on SOL/core momentum coupling
- and -
Part D. L-H Thresholds in Lower Limited versus Lower Diverted Discharges

Start with Shot C and optimize probe scans

Cycle through shots A, B, C until a good matched set is achieved.
"good match" = clean RF ramp with same NL04 at L-H transition time.

Repeat this for NL04=0.9e20

Repeat this for NL04=1.2e20 (or go directly to part E)

........
Part E. (Extra credit) Effect of Inner Gap

Repeat Shot A at NL04=0.9e20 with successively reduced inner gaps: 4, 2, 0 mm
Map change in L-H threshold powers
Record flows => do not scan ISP!
______________________________________________________________________________
Result:
A very productive run. We got good data on Parts C,D and E, completing the MP.

Parts C and D
We ran three equilibria - normal LSN, LSN with separatrix just grazing the inner
divertor nose, and discharges limited on the inner divertor nose. L-H transitions
were regularly attained in all three. At densities around NL04=0.7 the L-H threshold
power was essentially the same. At NL04=1.0 there was some tendency to require
more RF power (~1.2 versus ~1.0 MW) for the nose-limited case, but this may not be
significant, given the typical shot-to-shot variations. Good flow data were recorded
on probes and HIREX.

Part E
We scanned the inner gap from 15 mm to zero over about 9 shots. The L-H power
threshold did not change from the nominal 1 MW until the gap was reduced to under
2 mm. Below this distance, it is a very strong function of gap. An L-H transition
was achieved at 2.3 MW and 1.6 mm gap. Anything under 1.6 mm did not go into
H-mode at 2.3 MW. Good flow data were recorded for these shots also.

Helium was puffed from the inner wall capillary all day with flow data being
recorded by the Chromex spectrometer.

______________________________________________________________________________

Detailed Shot log:

01-03 Data system tests.

04- LIMITED on inner divertor nose ASP(+17), FSP(+23.8), ISP
=> No H-mode, NL04=0.66
05- LIMITED on inner divertor nose ASP(+17), FSP(+23.8), ISP
=> L-H at 1.15s, 1.0 MW, NL04=0.78
06- LIMITED on inner divertor nose ASP(+17), FSP(+26), ISP
=> L-H at 1.09s, .84 MW, NL04=0.72
07- SNL, SMALL gap to inner divertor nose ASP(+10), FSP(+12), ISP
=> L-H near 1.5s, injection, NL04=0.69
08- SNL, SMALL gap to inner divertor nose, ASP(+13), FSP(+14), ISP
=> L-H at 1.17s, 1.07 MW, NL04=0.68
09- SNL, NORMAL inner divertor nose gap. ASP(+14), FSP(-4), ISP
=> L-H at 1.18 s, 1.09 MW, NL04=0.75
10- SNL, NORMAL inner divertor nose gap. ASP(+14), FSP(-4), ISP
=> L-H at 1.25 s, 1.25 MW, NL04=0.67
11- SNL, NORMAL inner divertor nose gap. ASP(+14), FSP(-4), ISP
=> L-H at 1.11 s, 0.96 MW, NL04=1.0
12- SNL, NORMAL inner divertor nose gap. ASP(+14), FSP(-4), ISP
=> L-H at 1.15 s, 1.0 MW, NL04=1.0
13- SNL, SMALL inner divertor nose gap. ASP(+13), FSP(+14), ISP
=> L-H at 1.09 s, 0.95 MW, NL04=0.95
14- SNL, SMALL inner divertor nose gap. ASP(+13), FSP(+14), ISP
=> L-H at 1.25 s, 1.2 MW, NL04=1.0
15- LIMITED on inner divertor nose ASP(+17), FSP(+26), ISP
=> L-H at 1.35s, 1.3 MW, NL04=1.0
16- LIMITED on inner divertor nose ASP(+17), FSP(+26), ISP
=> L-H at 1.32s, 1.2 MW, NL04=1.0
17- SNL, NORMAL inner divertor nose gap. ASP(+14), FSP(-4), ISP
=> disrupted at 0.67 s
18- SNL, NORMAL inner divertor nose gap. ASP(+14), FSP(-4), ISP
=> L-H at 1.07 s, 0.75 MW, NL04=0.9, FSP a bit too deep.
19- SNL, NORMAL inner divertor nose gap. ASP(+14), FSP(-4), ISP
=> L-H at 1.05 s, 0.85 MW, NL04=0.86
20- no power shot
21- LIMITED on inner divertor nose ASP(+17), FSP(+26), ISP
=> L-H at 1.23s, 1.2 MW, NL04=.97
22- SNL, NORMAL inner divertor nose gap. but REDUCED inner wall gap. ASP(+14), FSP(-4)
Inner gap = 12 mm
=> L-H at 1.17s, 0.95 MW, NL04=.9, FSP a bit deep.
23- SNL, NORMAL inner divertor nose gap. but REDUCED inner wall gap. ASP(+14), FSP(-5)
Inner gap = 8 mm. ASP causes disruption.
24- SNL, NORMAL inner divertor nose gap. but REDUCED inner wall gap. ASP(+10), FSP(-5)
Inner gap = 6 mm
=> L-H at 1.19s, 1.0 MW, NL04=0.9
25- SNL, NORMAL inner divertor nose gap. but REDUCED inner wall gap. ASP(+10), FSP(-5)
Inner gap = 2 mm
=> L-H at 1.28s, 1.2 MW, NL04=? no TCI
26- SNL, NORMAL inner divertor nose gap. but REDUCED inner wall gap. ASP(+10), FSP(-5)
Inner gap = 2 mm
=> L-H at 1.28s, 1.1 MW, NL04=1.0, probe positions ok
27- SNL, NORMAL inner divertor nose gap. but REDUCED inner wall gap. ASP(+10), FSP(-5)
Inner gap = 0 mm
=> L-H at 1.28s, 1.4 MW, NL04=1.0, ASP could be deeper
28- SNL, NORMAL inner divertor nose gap. but REDUCED inner wall gap. ASP(+12), FSP(-5)
Inner gap = 0 mm
=> L-H at 1.37s, 1.9 MW, NL04=1.2 goes in H-mod when gap gets larger than zero
29- SNL, NORMAL inner divertor nose gap. but REDUCED inner wall gap. ASP(+12), FSP(-5)
Inner gap = 0 mm
=> L-H at 1.35s, 2.3 MW, NL04=1.16 goes in H-mod when gap gets larger than zero
30- SNL, NORMAL inner divertor nose gap. but REDUCED inner wall gap. ASP(+12), FSP(-5)
Inner gap wiggled
=> L-H at 1.09s, 2.3 MW, NL04=1.12, gap=2 mm and
L-H at 1.4s, 2.35 MW, NL04=1.2, gap=1.6 mm

Physics Operator Summaries
Entered: Jul 7 2004 04:36:49:693PM
Author: Jim Irby
Engineering Setup for Run 1040326 --- Experiments on Plasma Flows and
the L-H Threshold --- MP384

Engineering Operators: Dekow, Fitz, Byford, Parkin, Cochran
Session leader: Labombard
Physics operator: Irby, Rowan

ECDC overnight in D2 at 2e-4 Torr, stopping by 07:00

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

Power systems the same as last shot from run 1040325

A-coils should be disabled.

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)

Disable NINJA

Enable the following gate valves: ECE, VUV, DNB


-------------------------------------------------------------------------------
RF Setup: All four transmitters in RUN-ON by 08:00. D and E at 80 MHz

J-Port antenna will not be needed
-------------------------------------------------------------------------------


Summary
-------

First of all, the machine ran extremely well with 100 percent startup
during the run. Because of the development work done on run 1040325
it was very easy to generate the plasmas the session leader needed
since all that was required was a segment switch and adjustment in
density feedback. The PO did forget to tune RCUR to keep the outer
gap constant during some early shots, but we did correct this problem
later on (after almost losing a probe). RF ran well and provided
the power requested.


Problems
--------

We started out with three data system tests, first plasma on shot 4.
The data system problem was related to a crash of the Lowbrid, which
may have been related to upgrades made to the system last week.

We had an OH2L crowbar on shots 17 and 27 that resulted in
disruptions. Bill Cochran believes this problem was related to bad
contacts on the OH2L power supply shunts. The contacts have been
cleaned and we can hope this problem has been fixed.

Tf breaker pulled in check on shot 20, lost shot.


Score
-----


plasmas 04,05,06,07,08,09,10,11,12,13,14,15,16,17,18,19,21,22,23
24,25,26,27,28,29,30

tests 01,02,03

breaker pull 20

Session Leader Comments
Mar 26 2004 09:28:59:440AM1040326004Brian LabombardShot 04 LIMITED on inner div. nose, 0.8 MA, 5.4 tesla, No H-mode
ASP, FSP, ISP scanning at 0.65, 0.85, 1.05 seconds
ASP - ok
FSP - ok
ISP - ok, 10 mm outside sep.
Mar 26 2004 09:45:24:943AM1040326005Brian LabombardShot 05 LIMITED on inner div. nose, 0.8 MA, 5.4 tesla, L-H at 1.15 s, 1.0 MW, NL04=0.78
ASP, FSP, ISP scanning at 0.65, 0.85, 1.05 seconds
ASP - ok
FSP - ok
ISP - ok, 10 mm outside sep.
Mar 26 2004 10:05:43:140AM1040326006Brian LabombardShot 06 LIMITED on inner div. nose, 0.8 MA, 5.4 tesla, L-H at 1.09 s, 0.84 MW, NL04=0.72
ASP, FSP, ISP scanning at 0.65, 0.85, 1.05 seconds
ASP - ok
FSP - ok
ISP - ok, 10 mm outside sep.

Next shot: go to SMALL gap to inner nose.
Mar 26 2004 10:13:59:430AM1040326007Brian LabombardShot 07 LSN, SMALL gap to inner div. nose, 0.8 MA, 5.4 tesla, injection, tiny H-mode late
ASP, FSP, ISP scanning at 0.65, 0.85, 1.05 seconds
ASP - ok, could be deeper
FSP - ok, could be deeper
ISP - ok, 3 mm out

Next Shot: repeat
Mar 26 2004 10:26:53:973AM1040326008Brian LabombardShot 08 LSN, SMALL gap to inner div. nose, 0.8 MA, 5.4 tesla, L-H at 1.17, 1.07 MW, NL04=0.68
ASP, FSP, ISP scanning at 0.65, 0.85, 1.05 seconds
ASP - ok
FSP - ok
ISP - ok, 3 mm out

Next Shot: go to LSN with NORMAL gap
Mar 26 2004 10:43:25:480AM1040326009Brian LabombardShot 09 LSN, NORMAL gap to inner div. nose, 0.8 MA, 5.4 tesla, L-H at 1.18, 1.09 MW, NL04=0.75
ASP, FSP, ISP scanning at 0.65, 0.85, 1.05 seconds
ASP - ok
FSP - ok
ISP - ok

Next Shot: repeat
Mar 26 2004 10:55:23:587AM1040326010Brian LabombardShot 10 LSN, NORMAL gap to inner div. nose, 0.8 MA, 5.4 tesla, L-H at 1.25, 1.18 MW, NL04=0.67
ASP, FSP, ISP scanning at 0.65, 0.85, 1.05 seconds
ASP - ok
FSP - ok
ISP - ok

Next Shot: change to NL04=0.9
Mar 26 2004 11:11:54:933AM1040326011Brian LabombardShot 11 LSN, NORMAL gap to inner div. nose, 0.8 MA, 5.4 tesla, L-H at 1.11, 0.96 MW, NL04=1.0
ASP, FSP, ISP scanning at 0.65, 0.85, 1.05 seconds
ASP - ok
FSP - ok
ISP - ok

Next Shot: Repeat with NL04=0.85
Mar 26 2004 11:26:43:980AM1040326012Brian LabombardShot 12 LSN, NORMAL gap to inner div. nose, 0.8 MA, 5.4 tesla, L-H at 1.15, 1.0 MW, NL04=1.0
ASP, FSP, ISP scanning at 0.65, 0.85, 1.05 seconds
ASP - ok
FSP - ok
ISP - ok

Next Shot: go to LSN with SMALL gap to nose
Mar 26 2004 11:43:35:550AM1040326013Brian LabombardShot 13 LSN, SMALL gap to inner div. nose, 0.8 MA, 5.4 tesla, L-H at 1.09, 0.95 MW, NL04=0.95
ASP, FSP, ISP scanning at 0.65, 0.85, 1.05 seconds
ASP - ok
FSP - ok
ISP - ok, 4 mm out

Next Shot: repeat
Mar 26 2004 11:58:20:267AM1040326014Brian LabombardShot 14 LSN, SMALL gap to inner div. nose, 0.8 MA, 5.4 tesla, L-H at 1.25, 1.2 MW, NL04=1.0
ASP, FSP, ISP scanning at 0.65, 0.85, 1.05 seconds
ASP - ok
FSP - ok
ISP - ok, 4 mm out

Next Shot: go to LIMITED on inner div. nose
Mar 26 2004 12:14:56:130PM1040326015Brian LabombardShot 15 LIMITED on inner div. nose, 0.8 MA, 5.4 tesla, L-H at 1.35, 1.3 MW, NL04=1.0
ASP, FSP, ISP scanning at 0.65, 0.85, 1.05 seconds
ASP - ok
FSP - ok
ISP - ok, 9 mm out

Next Shot: repeat
Mar 26 2004 12:25:49:940PM1040326016Brian LabombardShot 16 LIMITED on inner div. nose, 0.8 MA, 5.4 tesla, L-H at 1.32, 1.2 MW, NL04=1.0
ASP, FSP, ISP scanning at 0.65, 0.85, 1.05 seconds
ASP - ok
FSP - ok
ISP - ok, 9 mm out

Next Shot: go back to LSN, with NORMAL gap
Mar 26 2004 12:39:53:723PM1040326017Brian LabombardShot 17 LSN with NORMAL gap to inner div. nose, 0.8 MA, 5.4 tesla, disrupted at 0.67
ASP, FSP, ISP scanning at 0.65, 0.85, 1.05 seconds
ASP - ok
FSP - ok, but may have been damaged.
ISP - ok

Next Shot: try again
Mar 26 2004 01:16:03:280PM1040326018Brian LabombardShot 18 LSN with NORMAL gap to inner div. nose, 0.8 MA, 5.4 tesla, L-H at 1.07s, 0.75MW, NL04=0.9
RF not clean.
ASP, FSP, ISP scanning at 0.65, 0.85, 1.05 seconds
ASP - ok
FSP - ok, a bit deep
ISP - ok

Next Shot: repeat
Mar 26 2004 01:22:34:957PM1040326019Brian LabombardShot 19 LSN with NORMAL gap to inner div. nose, 0.8 MA, 5.4 tesla, L-H at 1.05s, 0.85MW, NL04=0.86
RF not clean.
ASP, FSP, ISP scanning at 0.65, 0.85, 1.05 seconds
ASP - ok
FSP - ok
ISP - ok

Next Shot: go back to LIMITED on inner div. nose.
Mar 26 2004 02:16:54:020PM1040326021Brian LabombardShot 21 LIMITED on inner div. nose, 0.8 MA, 5.4 tesla, L-H at 1.23s, 1.2MW, NL04=0.97
ASP, FSP, ISP scanning at 0.65, 0.85, 1.05 seconds
ASP - ok
FSP - ok
ISP - ok, 10 mm out

Next Shot: go to LSN with NORMAL gap to inner nose but REDUCED inner wall gap
Mar 26 2004 02:27:00:377PM1040326022Brian LabombardShot 22 LSN, NORMAL gap on inner div. nose, with REDUCED inner wall gap
Inner gap = 12 mm
0.8 MA, 5.4 tesla, L-H at 1.17s, 0.95MW, NL04=0.9
ASP, FSP scanning at 0.65, 0.85, 1.05 seconds
ASP - ok
FSP - ok, bit deep

Next Shot: go to 5 mm gap
Mar 26 2004 02:47:49:947PM1040326023Brian LabombardShot 23 LSN, NORMAL gap on inner div. nose, with REDUCED inner wall gap
Inner gap = 8 mm
0.8 MA, 5.4 tesla, probe-induced disruption at 1.06 s
ASP, FSP scanning at 0.65, 0.85, 1.05 seconds
ASP - ok, too deep
FSP - ok

Next Shot: go to 5 mm gap
Mar 26 2004 03:04:08:217PM1040326024Brian LabombardShot 24 LSN, NORMAL gap on inner div. nose, with REDUCED inner wall gap
Inner gap = 6 mm
0.8 MA, 5.4 tesla, L-H at 1.19, 1.0MW, NL04=0.9
ASP, FSP scanning at 0.65, 0.85, 1.05 seconds
ASP - ok
FSP - ok

Next Shot: go to 2 mm gap
Mar 26 2004 03:18:35:577PM1040326025Brian LabombardShot 25 LSN, NORMAL gap on inner div. nose, with REDUCED inner wall gap
Inner gap = 2 mm
0.8 MA, 5.4 tesla, L-H at 1.28s, 1.2MW, NL04=?
ASP, FSP scanning at 0.65, 0.85, 1.05 seconds
ASP - ok
FSP - ok

Next Shot: repeat
Mar 26 2004 03:32:25:953PM1040326026Brian LabombardShot 26 LSN, NORMAL gap on inner div. nose, with REDUCED inner wall gap
Inner gap = 2 mm
0.8 MA, 5.4 tesla, L-H at 1.28s, 1.1MW, NL04=1.0
ASP, FSP scanning at 0.65, 0.85, 1.05 seconds
ASP - ok
FSP - ok

Next Shot: go to 0 mm
Mar 26 2004 03:49:53:097PM1040326027Brian LabombardShot 27 LSN, NORMAL gap on inner div. nose, with REDUCED inner wall gap
Inner gap = 0 mm
0.8 MA, 5.4 tesla, L-H at 1.28s, 1.4MW, NL04=1.0
ASP, FSP scanning at 0.65, 0.85, 1.05 seconds
ASP - ok
FSP - ok

Next Shot: repeat, ASP deeper
Mar 26 2004 04:16:23:220PM1040326028Brian LabombardShot 28 LSN, NORMAL gap on inner div. nose, with REDUCED inner wall gap
Inner gap = 0 mm
0.8 MA, 5.4 tesla, L-H at 1.37s, 1.9MW, NL04=1.2, when gap increases from zero.
ASP, FSP scanning at 0.65, 0.85, 1.05 seconds
ASP - ok
FSP - ok

Next Shot: repeat, more RF power
Mar 26 2004 05:05:51:193PM1040326029Brian LabombardShot 29 LSN, NORMAL gap on inner div. nose, with REDUCED inner wall gap
Inner gap = 0 mm
0.8 MA, 5.4 tesla, L-H at 1.35s, 2.3MW, NL04=1.16, when gap increases from zero.
ASP, FSP scanning at 0.65, 0.85, 1.05 seconds
ASP - ok
FSP - ok

Next Shot: repeat, square RF power program with wiggle in inner gap.
Mar 26 2004 05:14:47:217PM1040326030Brian LabombardShot 30 LSN, NORMAL gap on inner div. nose, with REDUCED inner wall gap
Inner gap = wiggled
0.8 MA, 5.4 tesla, L-H at 1.09s, 2.3MW, NL04=1.12, gap=2mm
L-H at 1.4s, 2.3MW, NL04=1.2, gap=1.6mm
ASP, FSP scanning at 0.65, 0.85, 1.05 seconds
ASP - ok
FSP - ok

Physics Operator Comments
Mar 26 2004 07:31:14:243AMJim IrbyEngineering Setup for Run 1040326 --- Experiments on Plasma Flows and the L-H Threshold --- MP384

Session leader: Labombard
Physics operator: Irby

ECDC overnight in D2 at 2e-4 Torr, stopping by 07:00

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

Power systems the same as last shot from run 1040325

A-coils should be disabled.

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)

Disable NINJA

Enable the following gate valves: ECE, VUV, DNB


-------------------------------------------------------------------------------
RF Setup: All four transmitters in RUN-ON by 08:00. D and E at 80 MHz

J-Port antenna will not be needed
-------------------------------------------------------------------------------
Mar 26 2004 07:45:43:137AMJim IrbyRun Plan Prepared by Brian:

Purpose:
Explore relationships between edge plasma flows, magnetic topologies,
and the L-H power threshold.

This is a continuation from 1040325, focusing on lower-limited
and lower x-point topologies.

Shot Plan:
All shots are 0.8MA, 5.4 tesla discharges.
Start: reload from Shot#1040325031 - LIMITED on inner div. nose,
running on segment#3

Note: This shot has the following setup:

Shot A - Segment#2, a SNL discharge with NORMAL inner
divertor nose gap. NL04=0.55e20

Shot B - Segment#3, a SNL discharge with SMALL inner
divertor nose gap. NL04=0.55e20

Shot C - Segment#4, a LIMITED discharge on inner divertor nose
NL04=0.55e20

Set probe scan times to 0.65, 0.85 and 1.05 seconds.
Program RF power ramp of 0.5 to 1.5 MW over time interval 0.95 to 1.5 sec.

We will be switching between Shots A,B,C most of the day.
........
Part C. Effect of inner divertor nose recycling on SOL/core momentum coupling
- and -
Part D. L-H Thresholds in Lower Limited versus Lower Diverted Discharges

Start with Shot C and optimize probe scans

Cycle through shots A, B, C until a good matched set is achieved.
"good match" = clean RF ramp with same NL04 at L-H transition time.

Repeat this for NL04=0.9e20

Repeat this for NL04=1.2e20 (or go directly to part E)

........
Part E. (Extra credit) Effect of Inner Gap

Repeat Shot A at NL04=0.9e20 with successively reduced inner gaps: 4, 2, 0 mm
Map change in L-H threshold powers
Record flows => do not scan ISP!
Mar 26 2004 09:09:02:713AM1040326001Jim IrbyLoaded shot 1040325031, seg #4 (SNL, 800kA, 5.4T, RXL -0.05)

Several bugs have been found in the TF scanner that should be fixed today.


Data system test


Mar 26 2004 09:09:19:557AM1040326002Jim IrbyData system test
Mar 26 2004 09:09:34:060AM1040326003Jim Irbydata system test
Mar 26 2004 09:27:59:627AM1040326004Jim IrbyAdded 2 ms to prepuff. Gas looked low from no power tests.

Good shot ---- plasma into rampdown

No h-mode, density higher than programmed and higher than shot 33 from yesterday

Mar 26 2004 09:43:38:393AM1040326005Jim IrbyRepeat and how density is under control this time

Plasma

Better density control
Mar 26 2004 09:59:12:817AM1040326006Jim IrbyRepeat. Brian wants to see the density drop more.

Good shot

Density down a little more and very close to 1040325033

Mar 26 2004 10:19:31:497AM1040326007Jim IrbyReduced prepuff by 1 ms

Changed to segment #3 ( RXL from -.05 to -.03)

Good shot

Mar 26 2004 10:25:55:800AM1040326008Jim IrbyRepeat

Got nice h-mode --- Brian is happy

Mar 26 2004 10:42:55:510AM1040326009Jim IrbySwitched to segment #2 (normal inner nose gap)

Good plasma
Mar 26 2004 10:55:34:460AM1040326010Jim IrbyIncreased prepuff by 1 ms

Good shot
Mar 26 2004 11:08:16:040AM1040326011Jim Irbynl_04 from 5.5 to 9.0e19 /m^2 --- staying with segment #2

Good plasma
Mar 26 2004 11:22:45:837AM1040326012Jim IrbyDensity request to 8.5e19/m^2 on nl04 --- staying with segment #2

Plasma

Mar 26 2004 11:43:40:140AM1040326013Jim IrbyMoved to segment #3, redrew density for 8.5e19/m^2

Plasma into rampdown


Mar 26 2004 11:52:11:900AM1040326014Jim IrbyRepeat

Good shot
Mar 26 2004 12:05:30:870PM1040326015Jim Irbygoing to segment #4 at nl04 of 8.5e19/m^2

good shot
Mar 26 2004 12:24:53:767PM1040326016Jim Irbyrepeat

good plasma
Mar 26 2004 12:46:04:917PM1040326017Jim Irbyback to seg 2 at 8.5e19/m^2

Disruption at 0.67 s

OH2L crowbar --- going into power room to check fuses, etc.



Mar 26 2004 01:03:55:593PM1040326018Jim Irbyreduced prepuff by 1 ms: pressure was a little high, plus last shot disrupted

plasma
Mar 26 2004 01:19:02:627PM1040326019Jim Irbyrepeat

good plasma

Mar 26 2004 01:24:50:117PM1040326020Jim IrbyBack to seg 4, nl04 at 8.5e19/m^2

Mar 26 2004 01:32:28:847PM1040326020Jim Irby
No power shot.
TF breaker pulled before the shot.
Mar 26 2004 02:13:44:800PM1040326021Jim IrbyGood shot

Mar 26 2004 02:27:02:283PM1040326022Jim Irbymoved to seg 2, nl04 at 8e19/m^2, clearin reduced by .007 m

good shot

Mar 26 2004 02:39:41:610PM1040326023Jim Irbyreduced clearin by .005 m ---- shot 22 was not really chanded by .007 m, but closer to .0007 m!

disruption at 1.05 s --- Brian thinks probe ventured too far in but survived

Mar 26 2004 03:00:46:680PM1040326024Jim Irbyreduced clearin another .002 m --- should set the gap at about .005 m

good shot --- inner gap at 0.06 m

Mar 26 2004 03:12:37:930PM1040326025Jim Irbyreduced inner gap by .004 m

rediced rcur by .002 m

good plasma

low laser level lost all by channel 6 of TCI --- still had feedback

Mar 26 2004 03:33:44:813PM1040326026Jim Irbyrepeat

good shot


Mar 26 2004 03:51:00:550PM1040326027Jim Irbyclearin reduced by .002 m, rcur reduced by .001 m

Lost plasma a little early at 1.67 s --- OH2L crowbar again
Mar 26 2004 04:10:07:043PM1040326028Jim Irbyextended clearin time near wall about 100 ms to account for later h-mode formation

good shot

h-mode still starts about when we move away from the inner wall
Mar 26 2004 04:42:57:883PM1040326029Jim Irbyrepeat with more rf power

(delay as we check OH2L IOC again --- it went when the breakers were closed)

good shot

Engineering Operator Comments
ShotTimeTypeStatusComment
108:18:33:780AMTestBadIgor Stopped
208:48:06:503AMTestOk
308:58:04:390AMTestOk
409:18:47:740AMPlasmaOk
509:35:07:477AMPlasmaOk
609:50:45:590AMPlasmaOk
710:04:52:870AMPlasmaOk
810:19:51:497AMPlasmaOk
910:33:42:110AMPlasmaOk
1010:47:36:310AMPlasmaOk
1111:01:47:810AMPlasmaOk
1211:17:13:033AMPlasmaOk
1311:31:12:737AMPlasmaOk
1411:45:10:330AMPlasmaOk
1512:00:21:800PMPlasmaOk
1612:18:31:730PMPlasmaOk
1712:31:28:510PMPlasmaBadOH@ and EF1 Comm flt
1801:00:15:247PMPlasmaOk
1901:13:54:917PMPlasmaOk
2001:28:39:137PMPlasmaBadTF type 1 fault
2101:59:04:170PMPlasmaOk
2202:17:28:270PMPlasmaOk
2302:31:24:227PMPlasmaOk
2402:53:25:923PMPlasmaOk
2503:06:34:860PMPlasmaOk
2603:23:30:973PMPlasmaOk
2703:36:21:003PMPlasmaBadOH2L IOC flt
2804:05:57:710PMPlasmaOk
2904:36:08:877PMPlasmaOk
3004:52:23:083PMPlasmaOk