Alcator C-Mod Run 960105 Information

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Miniproposals
Miniproposal:113
Date Filed: 4/13/1995
Title:Impurity Puffing to Induce the Detached Divertor Condition in
First Author:Steve Golovato
Session Leader:Gary McCracken (shots 1-18)

Operators
Session leader(s):Gary McCracken
Physics operator(s):Robert Granetz
Engineering operator(s):Vinny Bertolino

Engineering Operator Run Comment
granetz

Session Leader Plans

Physics Operators Plans

Session Leader Summaries
Entered: Jul 7 2004 03:49:14:900PM
Author: To Be Determined
Run Summary 960105 (Friday).
MP #113, Boronization of Alcator C-Mod

SL G M McCracken
PO R Granetz
EO V Bertolino
Purpose: To run a series of fiducial shots in order to get a good baseline
of machine operation before the boronization which is to be carried out on the
weekend 6/7 January.

It was initially intended that we should carry out the complete
program that was planned for the day after boronization. However due to time
limitations we just did the five fiducial shots and then a short density
scan.
In the first plasma shot,#009, the density did not get up to 1e20 until
0.8 s. In the subsequent shots it got to 1e20 at 0.6 s. In shots 13 and 14 we
increased the RF power to 2 MW from 0.75 -1.0 s. We then obtained a very marked
ELM free H-mode on the H-alpha signals. On shot 15 we injected a Li pellet at
0.75 s and got a weak PEP mode.
On shots 16 and 17 we attempted to get a higher density. On shot 16 we
got a smooth density ramp from nl04=0.8 at 0.4 s to 1.3e20 at 1.0 s. There was
a gradual reduction in the Isat and clear detachment at 1.1 e20. The next
shot, 018, there was a somewhat faster density ramp from 0.8 to 1.7e20 over the
same time interval. The detachment was even more marked and occured at
nl04=1.2e20. It will be interesting to see whether boronization decreases the
impurity content and therefore increases the critical density.
After discussion with Gunter Esser (KFA Julich) and Earl it was unclear
whether we expect to have too much or too little wall fuelling after
boronization. We concluded that we should go ahead with the ECDC cleaning in
He after the boronization. We ought however to be prepared to have plenty of
gas puffing during the tokamak run after boronization. It has been the Julich
experience that up to 5 times as much gas as normal is needed for about 20 shots
There were some problems with diagnostics. The Mo monitor valve opened
only intermittently. We had some data on shots 12 and 16 when the valve opened
half way through the shot; otherwise it was shut. It seems to be a problem
with the PLC programming and M May is looking into it. The Thomson scatering
was not working becuse of problems with stray light.

Shot summary:
1-8 PS problems
9 First fiducial shot density low until 0.8 s
10. Second fiducial shot
11. Third fiducial shot
12 Fourth fiducial shot
13 Fifth fiducial shot but with @MW RF power
14 Increase in density to 1.1e20 @ MW marked H-mode
15 Li pellet injection, weak PEP mode
16 Density ramp to 1.3e20. Detachment at 1.1e20
17 No toroidal field
18 Density ramp to 1.7e20. Very good detachment at 0.61 s

Program stopped at 12.50hrs in order to give adequate time to set up the
boronization



Physics Operator Summaries
Entered: Jul 7 2004 04:36:55:740PM
Author: To Be Determined
Physics Operator's summary for run 960105

MP 113-- Boronization run, but prior to any boronization (to get a good
baseline)

SL: G. McCracken
PO: R. Granetz
EO: V. Bertolino

Today's original run plan will have to be curtailed in order to allow cell
access for working on the boronization system. We wish to try the following
program today:

(0) Check out EF1 and OH1 supplies
(1) 5 fiducial shots
(2) Density scan at high RF power
(3) 1 PEP mode shot with Li pellet

Summary: A reasonable amount of useful baseline data was obtained, despite the
very limited amount of run time. (Problems with the EFC TMX supplies
delayed operation until 11:00, and we had to shut down by 13:00 in
order to permit access to the cell for working on the boronization
system.) In particular, a good series of 4-5 reproducible fiducial
shots was completed, as well as 1 PEP mode shot, and a few higher
density shots at Prf=2.2 MW.

Scorecard: 10 plasmas
1 fizzle
1 duds (no TF)
6 tests
----------
18 total

Run setup: ECDC in helium before run.
Start with fiducial shot 951215040.
Deuterium in K-side at 20 psi (used to be A-side), enabled for hybrid.
Deuterium in B-top at 5 psi (puff pre-fill), enabled for hybrid.
Argon in B-side-lower at 4-5 psi, but not enabled.
RF ready to go on first plasma shot.
LPI may be used late in the run.
Enable the ECE, VUV, Moly monitor, PCX, and TCX valves

Detailed shot log:

Shot 01 -- OH1 test.

Shot 02 -- Fizzle. Br too negative. Chopper TMX's failed.

Next shot: increase Br by 1.5 mT (from 0.0055 to 0.007 T)

Shot 03 -- Plasma, but disrupted at 0.2 s. No EFC, went vertically unstable.

Shot 04 -- EFC test. TMX's failed.

Shot 05 -- EFC test. TMX's failed.

Shot 06 -- EFC test. TMX's received its gates, but there still was no output.

Shot 07 -- EFC test. TMX's received its gates, but there still was no output.

Shot 08 -- EFC test. Finally got current in the EFC coils.

Shot 09 -- Plasma. Good fiducial shot. Prf=0.9-1.6 MW, nl_04=1.0e20 m-2.
No H-modes.

Next shot: repeat

Shot 10 -- Plasma. Another good fiducial shot. Prf=0.9 MW mostly.
Better density control. Still no H-modes.

Next shot: repeat

Shot 11 -- Plasma. Another good fiducial shot. Prf=0.9-1.6 MW. Maybe a
weak L-H transition at 0.99 s.

Next shot: repeat

Shot 12 -- Plasma. Another good fiducial shot. Prf=0.9-1.6 MW. Maybe a
weak L-H transition at 0.98 s

Next shot: repeat, except raise Prf to 2.5 MW.

Shot 13 -- Plasma. Good H-mode. Prf=2.2 MW. NL_04=1.0e20 m-2.

Next shot: raise density to nl_04=1.4e20 m-2. Also tweak gas
puff at 0.3-0.35 s to eliminate low level of hard x-rays (at
Amanda's request).

Shot 14 -- Plasma. H-mode. Prf=2.2 MW. NL_04=1.1e20 before RF, and
1.75e20 during the H-mode.

Next shot: Fire lithium pellet at t=0.75 s.

Shot 15 -- Plasma. Got lithium-induced PEP mode. No H-mode.

Next shot: Raise density to nl=1.5e20 m-2 by adding in extra
valve. No lithium injection.

Shot 16 -- Plasma. nl_04=1.2-1.3e20 m-2. Prf=0.9 MW only.

Next shot: more density and more voltage on extra fueling valve
(B-top, pulse-gas-4)

Shot 17 -- Dud. No TF.

Next shot: try again.

Shot 18 -- Plasma. Max nl_04=1.7e20 m-2. Plasma disrupted during rampdown
due to high density. RF pulse was only about 0.8 MW for 0.1 s.

End of run.

Session Leader Comments
Jan 5 1996 08:26:50:450AMGary McCrackenMP 113 Boronizxation of Alcator C-Mod
The objective of this run is to a have a series of fiducial
shots prior to the boronization, ie to do what we planned to do yesterday.
. This run will then be repeated immediately after boronization. The
run plan will follow the shot sequence plan in the MP.
5 standard fiducial shots
6 shot density scan
If time permits do an RF power scan

Jan 5 1996 02:42:30:550PMGary McCrackenSummary:
After a number of problems with the power supplies we managed to
get 5 good fiducial shots, as planned (shots 009 to 013). After shot 9,
when the density was low, the density was very constant and reproducible
On shots 13 and 14 we increased the RF power to 2 MW and got a marked
H-mode. On shot 15 we fired a Li pellet in and got a weak PEP mode. On
shots 16 and 18 we tried increasing the density, but unfortunately lost
the D antenna. Shot 17 had no toroidal field.

Jan 5 1996 08:44:55:530AM960105001Gary McCrackenOH coax test for first shot.
OK

Jan 5 1996 09:13:33:820AM960105002Gary McCrackenFizzle. No chopper.

Jan 5 1996 09:23:47:830AM960105003Gary McCracken.Early disruption, 0.2 s EFC failed

Jan 5 1996 09:52:52:210AM960105004Gary McCrackenTest shot, EFC only.

Jan 5 1996 09:54:12:340AM960105005Gary McCrackenTest shot, TMX supplies.
They are not giving any voltage.

Jan 5 1996 10:33:32:060AM960105006Gary McCrackenTest shot, TMX supplies.
Still no voltage

Jan 5 1996 11:07:44:980AM960105008Gary McCrackenMore EFC tests. Got current in the coils.

Jan 5 1996 11:23:52:500AM960105009Gary McCrackenTry a proper plasma shot.
Worked well. nl04 got to 1e20 at 0.8 s
ICRH !MW on D at 0.75 s, 0.75 MW on E at 0.95 s
Looks reasonable

Jan 5 1996 11:38:16:320AM960105010Gary McCrackenSecond fiducial shot. Looks good but RF power is a little lower.
The density increases more quickly and nl04 reaches 1e20 at 0.6 s
Unfortunately the Mo monitor was not enabled for any shot up to now.
There appears to be an impurity injection at 0.68 s, according to the
bolometers

Jan 5 1996 11:44:01:480AM960105011Gary McCrackenThird fiducial shot. Looks good, very similar to the previous shot.
The density again increases to 1e20 at 0.6 s
Mo monitor still not on.

Jan 5 1996 11:58:28:950AM960105012Gary McCrackenFourth fiducial shot. Looks good, very similar to the previous shot.
The density again increases to 1e20 at 0.6 s
Mo monitor on. Big rise in Mo when RF comes on.

Jan 5 1996 12:04:45:630PM960105013Gary McCrackenFifth fiducial shot. Increased ICRF to 2 MW
Looks good.
The density again increases to 1e20 at 0.6 s and then increases further
at 0.8 s when the RF comes on . Very marked ELM free H-mode
Valve to Mo monitor did not open, but Xrays indicate a large increase
in Mo

Jan 5 1996 12:17:25:460PM960105014Gary McCrackenTried to increase density with 2 MW RF power, but it did not go up
before the RF power came on
Large increase in nl04 to 1.8e20 when the RF comes on
Reasonable shot
Still no Mo monitor

Jan 5 1996 12:31:41:810PM960105015Gary McCrackennl04=1.4e 20 asked for with 2.5 MW RF power, but it did not go up
before the RF power came on
Li pellet injected at 0.75 s. nl04 went up to 2.1e20
Slight indication of a PEP mode. No H-mode
Reasonable shot
Valve on Mo monitor still did not open

Jan 5 1996 12:43:09:450PM960105016Gary McCrackennl04=1.5e 20 asked for but only got up to 1.25e20.
RF power down to 1 MW as we lost one transmitter
No Li pellet No H-mode
Reasonable shot
Valve on Mo monitor opened at at 0.63 s

Jan 5 1996 12:43:43:520PM960105017Gary McCrackenNo toroidal field , no plasma

Jan 5 1996 01:00:07:370PM960105018Gary McCrackenAsked for nl04=2e20. Turned on valve B top in addition to the feedback
valve. Density got to 1.5e20 at 0.7 s and kept rising up to 1.7e20 at
1.0 s. Reasonable shot.
There may be a very weak H-mode at 0.75 to 0.85 s when the RF is on.
The RF was only 0.75 MW as D antenna didn't come on
Mo monitor valve did not open

Physics Operator Comments
Jan 4 1996 06:23:05:260PM960105001Robert GranetzMP 113-- Boronization run, but prior to any boronization (to get a good
baseline)

SL: G. McCracken
PO: R. Granetz
EO: V. Bertolino

Today's run plan:
(0) Check out EF1 supplies (new transformer, other changes)
(1) 5 fiducial shots
(2) 6-shot density scan, alternating with fiducial shots (12 shots total),
at high RF power
(3) 2 RF power ramp shots (0.5-3.0 MW), alternating with fiducials (4
shots total),
(4) PEP mode with D or Li pellets (time permitting)

Jan 4 1996 06:24:08:490PM960105001Robert GranetzRun setup: ECDC in helium before run.
Start with fiducial shot 951215040.
Deuterium in K-side at 20 psi (used to be A-side), enabled for hybrid.
Deuterium in B-top at 5 psi (puff pre-fill), enabled for hybrid.
Argon in B-side-lower at 4-5 psi, but not enabled.
RF ready to go on first plasma shot.
LPI may be used late in the run.
Enable the ECE, VUV, Moly monitor, PCX, and TCX valves

Jan 5 1996 08:36:40:940AM960105001Steve WolfeShot 960105001 -
OH coax test.
Setup by Granetz for a fiducial shot; Wolfe filling in as Physop until
Bob gets in.

Everything looks ok. There was no coldstart, but it looks like the
hybrid ran ok on shot 1.

Jan 5 1996 09:08:04:560AM960105001Robert GranetzShot 01 -- OH1 test.

Jan 5 1996 08:54:21:440AM960105002Steve WolfeShot 960105002 -

Setup for a fiducial. The basis was apparently 951214040, as set up by
RSG. This may end up with too negative a Br (calling for .0055), but
we'll give it a try.

Fizzle. No chopper, but it didn't make it that far.
Lots of negative Br on the flux plot.

Jan 5 1996 09:04:17:700AM960105002Steve WolfeFor Shot 960105003 -

Increase Br by 1.5mT to .007
Turning back over to Bob Granetz, who has arrived.

Jan 5 1996 09:08:17:640AM960105002Robert GranetzShot 02 -- Fizzle. Br too negative. Chopper TMX's failed.

Jan 5 1996 09:24:25:950AM960105003Robert GranetzShot 03 -- Plasma, but disrupted at 0.2 s. No EFC, went vertically unstable.

Jan 5 1996 09:44:27:660AM960105004Robert GranetzShot 04 -- EFC test. TMX's failed.

Jan 5 1996 09:48:24:680AM960105005Robert GranetzShot 05 -- EFC test. TMX's failed.

Jan 5 1996 10:22:47:180AM960105006Robert GranetzShot 06 -- EFC test. TMX's received its gates, but there still was no output.

Jan 5 1996 11:04:53:500AM960105007Robert GranetzShot 07 -- EFC test. TMX's received its gates, but there still was no output.

Jan 5 1996 11:07:03:190AM960105008Robert GranetzShot 08 -- EFC test. Finally got current in the EFC coils.

Jan 5 1996 11:18:41:880AM960105009Robert GranetzShot 09 -- Plasma. Good fiducial shot. Prf=0.9-1.6 MW, nl_04=1.0e20 m-2.
No H-modes.

Next shot: repeat

Jan 5 1996 11:28:50:530AM960105010Robert GranetzShot 10 -- Plasma. Another good fiducial shot. Prf=0.9 MW mostly.
Better density control. Still no H-modes.

Next shot: repeat

Jan 5 1996 11:36:40:340AM960105011Robert GranetzShot 11 -- Plasma. Another good fiducial shot. Prf=0.9-1.6 MW. No H-modes

Next shot: repeat

Jan 5 1996 11:47:56:500AM960105012Robert GranetzShot 12 -- Plasma. Another good fiducial shot. Prf=0.9-1.6 MW. Maybe a
weak L-H transition at 0.98 s

Next shot: repeat, except raise Prf to 2.5 MW.

Jan 5 1996 12:00:39:230PM960105013Robert GranetzShot 13 -- Plasma. Good H-mode. Prf=2.2 MW. NL_04=1.0e20 m-2.

Next shot: raise density to nl_04=1.4e20 m-2. Also tweak gas
puff at 0.3-0.35 s to eliminate low level of hard x-rays (at
Amanda's request).

Jan 5 1996 12:15:39:030PM960105014Robert GranetzShot 14 -- Plasma. H-mode. Prf=2.2 MW. NL_04=1.1e20 before RF, and
1.75e20 during the H-mode.

Next shot: Fire lithium pellet at t=0.75 s.

Jan 5 1996 12:23:48:180PM960105015Robert GranetzShot 15 -- Plasma. Got lithium-induced PEP mode.

Next shot: Raise density to nl=1.5e20 m-2 by adding in extra
valve. No lithium injection.

Jan 5 1996 12:37:32:690PM960105016Robert GranetzShot 16 -- Plasma. nl_04=1.2-1.3e20 m-2. Prf=0.9 MW only.

Next shot: more density and more voltage on extra fueling valve
(B-top, pulse-gas-4)

Jan 5 1996 12:41:57:180PM960105017Robert GranetzShot 17 -- Dud. No TF.

Next shot: try again.

Engineering Operator Comments
ShotTimeTypeStatusComment
106:22:33:080PMTestOk
208:48:43:200AMPlasmaBadno chopper
309:10:48:620AMPlasmaBadno efc's
409:36:21:200AMTestOk
509:45:40:540AMTestOk
610:15:03:000AMTestOk
710:27:05:470AMTestOk
811:03:44:400AMTestOk
911:13:17:670AMPlasmaOk
1011:22:32:930AMPlasmaOk
1111:30:57:610AMPlasmaOk
1211:39:47:960AMPlasmaOk
1311:52:37:540AMPlasmaOk
1412:03:38:110PMPlasmaOk
1512:16:12:740PMPlasmaOk
1612:30:30:410PMPlasmaOk
1712:39:20:570PMPlasmaBadTF did not fire
1812:46:39:710PMPlasmaOk