Alcator C-Mod Run 1050309 Information

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Miniproposals
Miniproposal:409
Date Filed: 1/19/2005
Title:Phase Space of the Scrape-off-Layer Plasma
First Author:Brian Labombard
Session Leader:Brian Labombard (shots 30-30)

Operators
Session leader(s):Brian Labombard
Physics operator(s):Robert Granetz
Engineering operator(s):Bill Cochran,Sam Pierson,Bill Parkin

Engineering Operator Run Comment
MP 409 (con't): SOL Phase Space (day 2)

Session Leader Plans
Entered: Mar 9 2005 10:05:00:627AM
Author: Brian Labombard
Run Plan for 1050309

MP#409 "SOL Phase space studies" - Day 2

Overall Goal
Map out the 'phase space' of the SOL plasma, i.e. the relationships between
the 'transport state' (profile shapes, gradients, cross-field fluxes, advection
velocities, turbulence characteristics) and theory-based 'control parameters'
(local collisionality, magnetic field strengths, parallel connection length,...)
that may determine that state.

Today's Goals
We will continue from last Friday's run (1050304), attempting to finish data collection
at Ip=0.8 MA, Bt=5.4 tesla in lower single null, pushing the density up. Then we will start
collecting the data at Ip=0.4 MA, Bt=4.0 tesla and Ip=0.4 MA, Bt=2.7 tesla.

Run Preparation Tasks (for probe diagnostics)
- Reconfigure A14 and A12 digitizer connections to outer divertor probe
array according to file: "put_new_fast_refs_2005_mar01.tcl"
- Execute TCL>@put_new_fast_refs_2005_mar01.tcl
- Configure ASP bias supplies: PA93 amplifiers ("DC supply") in standard sweep mode,
"Sweep A" and "Sweep B" set to -200 volts
- Use IDL code to switch ASP probe triggering and ASP/FMP power supply biases
between one of two modes:
"Scan" mode - ASP: N,S,E,W electrodes in current mode, "DC supply"
Probe scanning three times during shot, 256k samples/channel
FMP: OSD**.p0 probes in current mode, "Sweep B" supply
OSD**.p1 probes in current mode, "DC -" supply
OSD**.p2 probes in floating mode, "DC +" supply
"Dwell" mode - ASP: W & S electrodes in current mode, "Sweep A" & "Sweep B"
N & E electrodes in floating mode
Probe in dwell mode, with 512k samples/channel
FMP: OSD**.p0 probes in current mode, "DC -" supply
OSD**.p1 probes in current mode, "DC -" supply
OSD**.p2 probes in floating mode, "DC +" supply
IDL code: mp409_scan.pro
undwell_scan_asp.pro
set_asp_pa93_sweep.pro
set_fmp_sweep.pro
mp409_dwell.pro
dwell_scan_asp.pro
set_asp_fluctuation_mp409.pro
set_fmp_fluctuation_mp409.pro

Run Preparation Tasks (for optical diagnostics)
- Set integration time on Xybion to 1 ms
- Connect the following fiber views for the fast diodes
Outer SOL views 1-3,5,7,9-14,31-40 (total of 21)
Innerwall SOL views B and C
- Connect the following fiber views for the CHROMEX
Outer SOL views 18-22,24-29 (total of 11)
Innerwall SOL views A,D,E,F - otherwise known as 1,4-6
- Set timing on fastdiode digitizers to 0.1 s after the A-B limiter NINJA puff timing


Plan
Load from shot#1050304024. This shot ran on segment#2. It was a LSN discharge
with Ip=0.8 MA, Bt= 5.4 tesla, NL04 = 0.9e20. Note: segment#3 has
a USN program that we will use (Segment#4 is double-null? will not be used today.)
Reprogram density to NL04=1.2e20

ASP, FSP, ISP programmed to scan at 0.65, 0.85, 1.05 seconds
NINJA gas puff for GPI and boron V spectroscopy entering plasma at 1.1s
Set NINJA for D2 puff at A-B limiter and B16-001. Plenum pressure of 10 PSI.

Shots

1 LSN, NL04 = 1.2, Scan mode
NINJA puff at 1.1 s, fast camera at 1.25 s
2 USN, NL04 = 1.2, Scan mode
NINJA puff at 1.1 s, fast camera at 1.25 s
Note: If MARFES persist, then we will skip the USN discharges.

3 USN, NL04 = 1.4, Scan mode
NINJA puff at 1.1 s, fast camera at 1.25 s
4 LSN, NL04 = 1.4, Scan mode
NINJA puff at 1.1 s, fast camera at 1.25 s

5 Fill NINJA plenum with 40 PSI D2
Set Xybion gain for NL04=2.4
Puff through B16-001 (inner midplane capillary) trigger=0.5s, duration=0.9s
(see shot#1021107016 as an example with 0.1s earlier trigger)
LSN, program NL04=1.0 - flat, get: NL04=1.4 to 2.7, from 0.7 to 1.2 s
Dwell mode,trigger=0.95 (dwell from 0.7 to 1.2s)

6 repeat 17: in Scan mode, with only ASP and ISP scanning at 0.8, 1.0, 1.2s
NL04 ~ 1.6, 2.2, 2.7

7 repeat 18: in Scan mode, with deep ASP scan at 1.2 s
NL04 ~2.7

Change to 0.4 MA, 4 tesla

8,9 LSN, NL04 = 0.5, Scan mode, optimize probe insertion
NINJA puff at 1.1 s, fast camera at 1.25 s
10,11 USN, NL04 = 0.5, Scan mode, optimize probe insertion
NINJA puff at 1.1 s, fast camera at 1.25 s

12 USN, NL04 = 0.4, Scan mode
NINJA puff at 1.1 s, fast camera at 1.25 s
13 LSN, NL04 = 0.4, Scan mode
NINJA puff at 1.1 s, fast camera at 1.25 s

14 LSN, NL04 = 0.3, Scan mode
NINJA puff at 1.1 s, fast camera at 1.25 s
15 USN, NL04 = 0.3, Scan mode
NINJA puff at 1.1 s, fast camera at 1.25 s

16 USN, NL04 = 0.2, Scan mode
NINJA puff at 1.1 s, fast camera at 1.25 s
17 LSN, NL04 = 0.2, Scan mode
NINJA puff at 1.1 s, fast camera at 1.25 s

18 LSN, NL04 = 0.6, Scan mode
NINJA puff at 1.1 s, fast camera at 1.25 s
19 USN, NL04 = 0.6, Scan mode
NINJA puff at 1.1 s, fast camera at 1.25 s

15 USN, NL04 = 0.7, Scan mode
NINJA puff at 1.1 s, fast camera at 1.25 s
16 LSN, NL04 = 0.7, Scan mode
NINJA puff at 1.1 s, fast camera at 1.25 s

Change to 0.4 MA, 2.7 tesla

17 LSN, NL04 = 0.5, Scan mode, optimize probe insertion
NINJA puff at 1.1 s, fast camera at 1.25 s
18 USN, NL04 = 0.5, Scan mode, optimize probe insertion
NINJA puff at 1.1 s, fast camera at 1.25 s

19 USN, NL04 = 0.4, Scan mode
NINJA puff at 1.1 s, fast camera at 1.25 s
20 LSN, NL04 = 0.4, Scan mode
NINJA puff at 1.1 s, fast camera at 1.25 s

21 LSN, NL04 = 0.3, Scan mode
NINJA puff at 1.1 s, fast camera at 1.25 s
22 USN, NL04 = 0.3, Scan mode
NINJA puff at 1.1 s, fast camera at 1.25 s

23 USN, NL04 = 0.2, Scan mode
NINJA puff at 1.1 s, fast camera at 1.25 s
24 LSN, NL04 = 0.2, Scan mode
NINJA puff at 1.1 s, fast camera at 1.25 s

25 LSN, NL04 = 0.6, Scan mode
NINJA puff at 1.1 s, fast camera at 1.25 s
26 USN, NL04 = 0.6, Scan mode
NINJA puff at 1.1 s, fast camera at 1.25 s

27 USN, NL04 = 0.7, Scan mode
NINJA puff at 1.1 s, fast camera at 1.25 s
28 LSN, NL04 = 0.7, Scan mode
NINJA puff at 1.1 s, fast camera at 1.25 s

Physics Operators Plans
Entered: Mar 8 2005 05:21:51:430PM
Author: Robert Granetz
Engineering setup for Tuesday, 09 Mar 2005

MP 409 (con't): SOL Phase Space (day 2)

Session leader: B. Labombard
Physics operator: R. Granetz

Overnight ECDC in D2.

Run begins at 10:30 and ends at 18:00.

Power systems as on 1050304024, including A-coils

Gas Setup:
fill B-Top with 6 psi D2 Hybrid enabled (PG4)
fill B-side lower with 2 psi Ar Hybrid enabled (PG1)
leave B-side upper with He3 Hybrid disabled
fill (former) C-side with 30 psi D2 Hybrid enabled (PG3)
leave J-bot Hybrid disabled (PG2)

Disable NINJA, but fill the plenum with 10 psi D2.

Torvac setup: GV1 closed; bypass to RGA open
Torus gate valves closed for 5 minutes after shot

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

Necessary diagnostics:
Scanning probes, GPI (including fast diodes), Xybion imaging

-------------------------------------------------------------------------------
RF Setup: Absolutely NO RF TODAY !

-------------------------------------------------------------------------------
Run plan:

Start from 1050304024 (0.8 MA, 5.4 T, lower single null, nl_04=1.0e20 m-2),
and plunge/probe away.

During the day we will also run some upper null equilibria, and change
the density, and change the toroidal field (to 4.0 T and 2.7 T) and
plasma current.

Session Leader Summaries
Entered: Mar 9 2005 09:42:55:983PM
Author: Brian Labombard
Run Summary for 1050309

MP#409 "SOL Phase space studies" - Day 2
___________________________________________________________________________________
A number of problems plagued the run today. We made very little progress towards
the MP - only 4 shots were obtained with desired conditions. Shots 1-12 were either a
fizzle or died very early (~0.2-0.5s), appearing to be gassed to death in most cases.
Associated with this was a 'fireworks display' of UFOs, seen on WIDE1, LH, and JANT
cameras. These seemed to indicate something (perhaps dust?) coming into the plasma
mostly around D-port (but not associated with the LH launcher). One hypothesis was
that the Thomson scattering calibration performed over the weekend was to blame.
A thought was that the 500 torr of D2 partially filled up some trapped volume(s)
behind gate valves and that this was causing D2 fueling, perhaps as a gate valve
momentarily lurched in response to poloidal fields tickling its solenoid valve.
We stopped to have the trapped volumes behind the E-top and E-bottom gate valves
pumped out. A few shots later we got a full length plasma, although we may have gotten
them anyway without doing the pump-out. The 'fireworks' persisted at a lower
level even once we got full length discharges. The cause of the 'fireworks' is still a
mystery, although it is tempting to blame it on dust that was stirred up by the
Thomson D2 back-fill last weekend.
We had numerous cell accesses and subsequent delays, one to check on the status of the
Thomson alignment targets (ok). Thrown into the mix to elevate aggravation was a problem
with the X server on the session leader's workstation (WS21 - not useable yet) and the
death of a PLC crate controller for the F-port scanning probe just before the run.
We then settled into a fizzle/plasma rhythm after shot 13 and got some moderately high
density data points (NL04 ~ 1.2, 1.4) in LSN and USN - that's all.

Quick shot summary
1-12 short plasmas. Unknown source of D2 gas input. Fireworks display.
13 - LSN, NL04=0.78, ISP, at 0.65, 0.85, 1.05
14 - Fizzle
15 - LSN, NL04=1.0-1.2, ASP(+6), FSP(+3), ISP, at 0.65, 0.85, 1.05
16 - Fizzle
17 - LSN, NL04=1.0-1.2, ASP(+6), FSP(+3), ISP, at 0.65, 0.85, 1.05 - good targeting, ASP, ISP a bit deep
18 - Fizzle
19 - USN, NL04=1.2, ASP(+6), FSP(+3), ISP, at 0.65, 0.85, 1.05 - targeting ok - it's MARFing and cold
20 - Fizzle
21 - LSN, NL04=1.1 to 1.5, ASP(+5), FSP(+3), ISP, at 0.65, 0.85, 1.05 - targeting ok
22 - Fizzle
23 - Fizzle

Physics Operator Summaries
Entered: Mar 9 2005 06:17:43:157PM
Author: Robert Granetz
Physop summary for Wednesday 09 March 2005:

Things did not go smoothly today. We started off with very short,
resistive, disruptive plasmas. These seemed to have a lot of deuterium gas
puffing, even though it wasn't coming from any of the controlled gas
valves. After shot 9 we finally guessed that trapped volumes behind gate
valves might have been partially filled with D2 during the Thomson
calibration on Sunday, when the torus was backfilled with 500 torr of D2.
Apparently one or more of these gate valves was burping back some of this
trapped deuterium gas during the pulse, which was causing our problems.
Tommy Toland pumped out the trapped volumes, and this apparently solved the
problem; we began getting full length plasmas on shot 13.

With the new video cameras we saw showers of dust/particulates traveling in
the counter-current direction in the divertor region, apparently coming
from somewhere around E-bottom. This tended to decrease during the day.

After we started getting full length plasmas, we then alternated between
fizzles and plasmas for the remainder of the day. We had some upper and
lower null plasmas at various densities, with NINJA puffing and scanning
probes working, but very little was accomplished on the MP. To add to the
difficulties, the computers/MDS had numerous meltdown problems during the
first part of the run. Also, the F27 partial flux loop had some
intermittent problems after disruptions.

Session Leader Comments
Mar 9 2005 11:05:07:957AM1050309001Brian LabombardShot 1 Died at 0.12s Load of gas in the vessel ~ 28 mtorr - something ablated?
Can use this shot to cross-calibrate gauges at high pressure (if it is D2)

Mar 9 2005 03:44:28:347PM1050309013Brian LabombardShot 13 LSN, Ip=0.8 MA, Bt= 5.4 T, NL04=0.78
ISP scanning at 0.65, 0.85, 1.05s
ASP -
FSP -
ISP - to sep


Next: Go to NL04=1.2
Mar 9 2005 04:22:03:427PM1050309015Brian LabombardShot 15 LSN, Ip=0.8 MA, Bt= 5.4 T, NL04=1.0, 1.1, 1.2
ISP scanning at 0.65, 0.85, 1.05s
ASP - good, could be deeper
FSP - good
ISP - could be deeper
Xybion camera saturated


Next: repeat with 1mm smaller inner gap and xybion gain turned down
Mar 9 2005 04:46:24:440PM1050309017Brian LabombardShot 17 LSN, Ip=0.8 MA, Bt= 5.4 T, NL04=1.0-1.2
ISP scanning at 0.65, 0.85, 1.05s
ASP - a bit deep
FSP - ok
ISP - to sep and beyond
Xybion camera ok


Next: go to USN at LN04=1.2
Mar 9 2005 06:09:25:160PM1050309019Brian LabombardShot 19 USN, Ip=0.8 MA, Bt= 5.4 T, NL04=1.2
ISP scanning at 0.65, 0.85, 1.05s
ASP - good targeting
FSP - ok
ISP - to sep

Next: go to LSN at LN04=1.4
Mar 9 2005 06:09:45:283PM1050309021Brian LabombardShot 19 LSN, Ip=0.8 MA, Bt= 5.4 T, NL04=1.1 to 1.5
ISP scanning at 0.65, 0.85, 1.05s
ASP - good targeting
FSP - could be deeper
ISP - to sep

Next: go to USN at NL04=1.4

Physics Operator Comments
Mar 9 2005 11:03:53:970AM1050309001Robert GranetzPlasma, but very short. It started disrupting at t=0.11 s. The "LH" camera view
shows a shower of projectiles in the divertor.

Next shot: try again, no changes. Note that the NINJA is enabled.
Mar 9 2005 12:05:25:550PM1050309002Robert GranetzWhat happened to shot 2 ?
Mar 9 2005 12:05:54:363PM1050309003Robert GranetzNo power test. We're having lots of problems with computer/MDS meltdown.
Mar 9 2005 12:34:02:080PM1050309004Robert GranetzAnother short disruptive shot. More swarms of particulates showing up
on the Wide-1 camera. Gas pressure looks fine until the disruption.

I don't understand the reason for these early disruptions.

Next shot: increase pre-fill by 2 ms, increase early preprogrammed gas puffing.
Mar 9 2005 01:10:36:347PM1050309005Robert GranetzSlightly longer...finally disrupts at 0.25 s after becoming very resistive.
Density climbs too quickly, but the valves are turned off.

Earl reports D/H of 100%, but none of the valves seems to be
malfunctioning, and the overall pressure is fine until the disruption

We'll have a cell access to resurrect the WIDE-2 video view (F-port)

Next shot: repeat, with WIDE-2 view
Mar 9 2005 01:28:46:597PM1050309006Robert GranetzAnother short, resistive, disruption. The JANT and WIDE-1 cameras are showing
lots of molten stuff in the divertor traveling around toroidally (counter-current),
but the WIDE-2 view doesn't see it.

Next shot: switch to upper null to see if the lower divertor stuff goes away.
(Switch on segment 3 and turn off segment 2).
Mar 9 2005 01:38:57:503PM1050309007Robert GranetzAnother short disruptive shot with lots of glowing stuff flying around the
lower divertor region. The plasma disrupted just before the upper x-point
would have formed, but it didn't seem to matter as far as the injections.

I guess we might just have to try and burn off whatever is causing this.

Next shot: go back to lower single null and bang away.
Mar 9 2005 01:57:38:940PM1050309008Robert GranetzGetting longer, but still ugly. Huge density, even though the gas valve
turns off (due to proper feedback).

Lower single null, 0.7 MA. Disrupts at 0.54 s. Lots of hard x-rays.

Next shot: bang away again
Mar 9 2005 02:34:47:240PM1050309009Robert GranetzPlasma. Disrupted at 0.75 s. Density was nearly at the correct value this time.
Still has runaways.

Cell access for various purposes, including checking the TS to make sure that
nothing was left amiss after this past weekend's calibrations.

Tommy will pump out the trapped volumes behind the E-top and E-bottom gate
valves. Perhaps these filled up with D2 during the high-pressure Thomson calibration
on Sunday, and the gate valves are momentarily leaking during the shot. Steve
Wolfe points out that this may also be blowing in dust from E-bottom, which is what
we're seeing on the video views.

Next shot: reduce nl_04 to 0.8e20 m-2
Mar 9 2005 03:04:20:080PM1050309010Robert GranetzDud. And the data system may be hung. I'm just having too much fun today.

Next shot: increase pre-fill pulse by 2 ms.
Mar 9 2005 03:17:22:863PM1050309011Robert GranetzDud again. Fields look okay. Pre-fill pressure is still lower than on
shot 9 (most recent plasma).

Next shot: increase pre-fill another 3 ms (to 26 ms).
Mar 9 2005 03:27:18:533PM1050309012Robert GranetzFizzle. Progress, sort of. Current rampup was too slow.

Next shot: remove 1 ms from pre-fill and repeat.
Mar 9 2005 03:42:49:440PM1050309013Robert GranetzPlasma. Good, full-length shot (finally). 0.8 MA, 5.4 T, nl=0.8e20 m-2 (as programmed), lower single
null.

Next shot: raise nl_04 to 1.2e20 m-2. Enable argon again.
Mar 9 2005 03:51:35:020PM1050309014Robert GranetzFizzle. Current rise was too slow.

Next shot: back off another 1 ms on the pre-fill.
Mar 9 2005 04:17:58:597PM1050309015Robert GranetzPlasma. Good shot. NINJA comes on at 1.1 s and ramps up the density.

Next shot: decrease CLEARIN by 1 mm, keeping RCUR the same (so the outer gap
will also decrease by 1 mm).
Mar 9 2005 04:27:48:270PM1050309016Robert GranetzFizzle. Might have been due to a flake-out of the F27 partial flux loop. But
the loop was working again at the end of the shot.

Next shot: reduce pre-fill by 1 ms.
Mar 9 2005 04:41:37:177PM1050309017Robert GranetzPlasma. Good shot.

Next shot: upper null, same density as the current shot (nl=1.2e20 m-2)
Mar 9 2005 05:08:19:067PM1050309018Robert GranetzFizzle. We've got a good plasma/fizzle/plasma alternating pattern here.

Next shot: reduce Br by 0.5 mT and tweak pre-fill gas down a touch
Mar 9 2005 05:22:03:690PM1050309019Robert GranetzPlasma. Upper null. Disrupted at 1.50 s

Next shot: back to lower null, but raise nl to 1.4e20 m-2. Also reduce
pre-fill puff another 1 ms.
Mar 9 2005 05:30:30:677PM1050309020Robert GranetzFizzle.

Next shot: decrease pre-fill pulse another 1 ms
Mar 9 2005 05:48:06:113PM1050309021Robert GranetzPlasma. Good shot. Lower null. nl=1.4e20 m-2 until NINJA turns on and pushes
the density up to a disruption.

Startup just barely made it.

Next shot: take another 1 ms off the pre-fill. Upper null, same density
as the current shot (nl=1.4e20 m-2).
Mar 9 2005 05:55:34:737PM1050309022Robert GranetzFizzle. The alternating pattern continues.

Next shot: reduce pre-fill again. This will be the last shot of the run.

Engineering Operator Comments
ShotTimeTypeStatusComment
110:52:24:613AMPlasmaOkNo power system faults
312:02:58:877PMTestOkData System Test Shot
412:12:34:423PMPlasmaOk
512:37:28:127PMPlasmaOk
601:10:04:720PMPlasmaOk
701:29:05:770PMPlasmaOk
801:41:59:173PMPlasmaOk
901:58:28:740PMPlasmaOk
1002:54:22:490PMPlasmaOk
1103:07:19:817PMPlasmaOk
1203:19:39:520PMPlasmaOk
1303:32:27:393PMPlasmaOk
1403:45:28:643PMPlasmaOk
1504:08:56:080PMPlasmaOk
1604:22:57:753PMPlasmaOk
1704:35:33:067PMPlasmaOk
1805:01:03:613PMPlasmaOk
1905:13:22:173PMPlasmaOk
2005:26:51:393PMPlasmaOk
2105:39:19:863PMPlasmaOk
2205:51:41:970PMPlasmaOk
2306:04:27:300PMPlasmaOk