Alcator C-Mod Run 1060329 Information

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Miniproposals
Miniproposal:446
Date Filed: 3/22/2006
Title:Intra-Shot Diborane Injection in Alcator C-Mod
First Author:Jim Irby
Session Leader:Jim Irby (shots 1-24)

Operators
Session leader(s):Jim Irby
Physics operator(s):Jim Irby,Earl Marmar
Engineering operator(s):Ed Fitzgerald,Bill Byford,Gary Dekow

Engineering Operator Run Comment
MP430 Between shot boronization PO:Irby SL:Lipschultz EO:Fitzgerald,Byfo

Session Leader Plans
Entered: Mar 28 2006 02:29:01:077PM
Author: Bruce Lipschultz
Engineering setup:
-------------------------------------------------------------------------------

Power systems as on 1060321011
A-coil configuration: normal [+Dtop -Dbot -Jtop +Jbot] and enabled.
C-coil Start=0.3sec, Invert=2.0sec

ICRF in Run-on by 08:30AM

Gas Setup:
----------
fill B-top 6psi D2 Hybrid Enabled (PG4)
fill B-side lower 1 psi Argon Hybrid Disabled (PG1)
leave B-side Upper alone (15psi He3) Hybrid Enabled (PG2)
fill B-main 40psi D2 Hybrid Enabled (PG3)
NINJA: 10psi D2

*** Boronization system set up for between-shot boronization
*** 20 min boronization before run with scan from 50 to 92 cm, no pulsing. This should be followed by 30-40 minutes of ECDC in He.
*** We will be using 20% diborane 80% He mixture which has twice the amount of diborane as usual.

Enable ECE, VUV, Z-bolo shutter for all plasma shots; these must be disabled
for between-shot boronization

The A-Side TV camera shutter must be CLOSED before the boronizations (before the run and for the rest of the day).

The MSE shutter must be CLOSED before the start of the run, and remain closed
throughout the day.

-------------------------------------------------------------------------------
SL plan
-------------------------------------------------------------------------------

MP430 - Between shot boronization

Assume 10 minute boronization length to start with. Pressure 5
mTorr. Pause at center of each scan. Steady ECDC, no pulsing.

To reduce fizzles after boronization the prepuff is greatly reduced
see 1050810xxx and wait to get the pressure down to <2.5x10-5 Torr

0) Boronize before the run for 20 minutes (scan 50-92 cm, no pulsing). Followed by 30-40 minutes of He ECDC (44-95 cm scan).

1) Take shots to establish a fiducial discharge (1 MA standard
shot. This will be the un-boronized background.

2) Boronize sequence (1 shot to measure effect, 2nd shot to determine
if it has worn off) using 10 cm wide scans to cover from 90 to 50
cm. Work from outer major radius inward in 10 cm steps.

3) Once done with the scan, return to the most effective
location to examine reproducibility.

4) Scan using 5 cm stepsize on either side of the best location.

Potential next steps

- Switch in 10% diborane 90% He mixture bottle.

- Compare the usual boronization including pulsed ECDC with leaving
the ECDC on steadily during the period.

- If not done earlier then reduce the length of boronizations now to
10 and 5 minutes length (4 shots min. if not including fizzles).

- Compare boronization lifetime by comparing D&E heated versus J heated.
Entered: Mar 29 2006 12:20:17:793PM
Author: Jim Irby
Session Leader Plan for Wednesday 29-Mar-2006

MP466 Intra_Shot Diborane Injection in Alctor C-Mod

Session leader: Irby
Physics operator: Marmar

Overnight ECDC in D2, and bake at 60 C.

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

Power systems as on 1060328010 (1.0 MA fiducial, 5.4 T, LSN)

A-coil configuration: normal [+Dtop -Dbot -Jtop +Jbot] and enabled.

Gas Setup:

fill B-Top with 6 psi D2 Fill select enabled (PG4)
fill B-side lower with 1 psi Ar + 2 psi Ne Hybrid DISABLED (PG1)
leave B-side upper as is Hybrid DISABLED (PG2)
fill B-main (C-side) with 40 psi D2 Hybrid enabled (PG3)
fill NINJA with 12 psi D2 Enabled

Enable the following gate valves and shutters: TCI and YAG

Torvac setup: GV1 closed with bypass at 180 clicks
GV2 set to toggle closed at pulse for 300 s

Startup should use static fill.


Shot Sequence:

1-3 Produce LSN, rf fiducial shot with at least 2 MW of ICRF
power. Demonstrate that the discharges are reproducible (fiducial:
1060328010)

4-8 Begin diborane injection with 500 ms pulse at t=450 ms and ICRF at
650 ms. Modify gas puff as required to eliminate disruptions.

9-17 Assuming stable conditions have been found, monitor plasma
performance over several constant discharges.

If an improvement in performance is seen, stop He/ B2D6 puff for two
shots and judge how long the effects last.

18-21 Double null operation (1050303024 --- seg 4)

22-23 Return to LSN to observer any changes

23-30 USN operation if no improvements noted otherwise continue DN or
return to LSN.

Physics Operators Plans
Entered: Mar 28 2006 05:53:05:707PM
Author: Jim Irby
************** The cell will be open before the run so that work *************
************** can be done in the cell on the RF systems. We will ***********
************** evaluate what MP can be run as we learn more about ************
************** what rf power will be available. There will be no attempt at **
************** boronization before the run.

Session Leader Summaries
Entered: Mar 30 2006 07:34:31:993PM
Author: Jim Irby
MP466 Intra_Shot Diborane Injection in Alctor C-Mod

Session leader: Irby
Physics operator: Marmar

Overnight ECDC in D2 with bake at 60 C was performed


We orginally planned to run MP430, between shot boronization, but
after working on the ICRF systems before the run, there was not enough
time to complete it, so we switched to MP466. Dicharges 001 to 003
were setup for MP430, but were also fine for MP466, so no changes to
the plasma configuration were required when we switched
mini-proposals.

The primary objectives of this run were to see how much diborane we
could inject into the plasma without causing disruptions, and to judge
if the diborane affected performance positively. All discharges were
SNL, 1 MA, rf fiducial discharges, with an nl04 request of 0.9e20/m^2,
and rf power from J- and E-Port antennas of 3 MW. We did not have
time to try other configurations.

The 20% B2D6 + 80% He bottle was used to fuel the plasma through the
boronization manifold at the top of the vessel. The diborane
regulator was set to 10 psi. Tests on calibraton run 1060327, shots
001 to 004, indicated we could get about 50 Torr-l/s of gas through
this system. The gas typically took about 100 ms to indicate on the
vacuum gauges after the pulse was initiated.

We puffed up to 27.5 Torr-l of He+B2D6 gas into the vessel during the
discharge. This amount of gas could double the density following the
H-Mode and caused the plasma to disrupt during rampdown as early as
1.6 s. Discharges without the puff lasted about 1.95 s. On early
disruption at 0.392 s was caused by injecting too much gas early in
the discharge (0.1 to 0.35 s). Following shot 008 we puffed gas both
before and during or after the rf in an attempt to get as much
diborane into the discharge as possible.

The 27.5 Torr-l of injected gas would result in at most 2 monolayers
of boron deposited on the vessel walls, assuming a uniform depositon
over 10 m^2 of surface. So it is not surprising that we did not see
changes in machine performance. The quality of the H-Modes, the
carbon III levels, stored energy, and radiation, among other
indicators, did not show much change following several discharges with
diborane puffing. We did note however, that the performance of the
J-Port antenna did improve with the puff. This effect has been seen
previously with pure helium puffs.




Log File
comparison discharges





Physics Operator Summaries
Entered: Mar 31 2006 05:04:40:320PM
Author: Earl Marmar
Marmar took over from Irby as physop after shot 3, so he could switch to session leader for MP 446, Intra-shot diborane injection

The run went well. Shot 4 had a dpcs issue during init, possibly due to entering init before load/clean was complete, resulting in a power supply dud.

The last 2 shots of the day (fizzle, dud) had flux loop f25 offset problems, which may have caused the loss of startup.

The diborane puffing went well (from the physop point of view). See the session leader summary for physics results.

Scorecard (including the first 3 shots):

plasmas 21
fizzle 1
dud 1
power supply dud 1

total cycles 24




Session Leader Comments
Mar 29 2006 01:50:35:860PM1060329005Jim IrbyDiborane puff from 0.75 to 1.0 s
Diborane regulator set to 10 psi
VUV gatevalve open
Z-Bolo shutter open
A-Port shutter open
NINJA is puffing into plasma by 1.1 s; D2 at 12 psi
DNB firing at 1.0 s
GV1 closed with bypass at 180 clicks
GV2 will be left open

plasma into rampdown but no Diborane --- no J-Port power

suspect interlock problem with z-bolo, VUV, or DNB --- all disabled for next shot
Mar 29 2006 02:10:17:820PM1060329006Jim IrbyDiborane puff from 0.75 to 1.0 s
Diborane regulator set to 10 psi
VUV gatevalve open
Z-Bolo shutter open
A-Port shutter open
NINJA is puffing into plasma by 1.1 s; D2 at 12 psi
DNB firing at 1.0 s
GV1 closed with bypass at 180 clicks
GV2 will be left open

Z-bolo and vuv enables for this shot. Joe also thinks he has fixed the problem with the VUV interlock

plasma to 1.67 s --- boron puff was enough to shorten discharge

see mass 32 on RGA following discharge


Mar 29 2006 02:26:14:857PM1060329007Jim Irbydiborane from 0.75 to 0.95 s

plasma for 1.75 s

Mar 29 2006 02:32:59:220PM1060329008Jim Irbydiborane from 0.75 to 0.95 s

plasma for 1.75 s


Mar 29 2006 02:56:56:950PM1060329009Jim Irbydiborane:
0.20 to 0.30 s
0.75 to 0.95 s

plasma for 1.74 s


Mar 29 2006 03:09:46:277PM1060329010Jim Irbydiborane:
0.20 to 0.30 s
1.00 to 1.5 s

plasma for 1.59 s


Mar 29 2006 03:17:20:307PM1060329011Jim Irbydiborane:
0.15 to 0.25 s
1.00 to 1.50 s

plasma for 1.67 s

ICRF has looked very good for the last couple of shots

Mar 29 2006 03:38:19:720PM1060329012Jim Irbydiborane:
0.10 to 0.25 s
1.00 to 1.50 s

put in some diborane before we divert

plasma to 1.65 s

early ciii signal down for the first time today

very little D2 left --- mostly He


Mar 29 2006 03:50:08:023PM1060329013Jim Irbydiborane:
0.10 to 0.25 s
1.00 to 1.50 s

repeat of shot 12

plasma for 1.66 s

ciii signal back up and starting a little later


Mar 29 2006 04:01:51:497PM1060329014Jim Irbyno diborane puff

plasma for 1.94 s

rf looks good

prad up, stored energy up


Mar 29 2006 04:06:38:030PM1060329015Jim Irbyno diborane puff

plasma for 1.94 s

j-port rf trips out at 1.14 s --- getting worse?


Mar 29 2006 04:53:01:610PM1060329016Jim Irbydiborane puff:
0.100 to 0.350 s
1.000 to 1.300 s

plasma for 0.386 s --- pulled PF breaker, will have to go in power room

all clear in power room
Mar 29 2006 05:00:02:970PM1060329018Jim Irbydiborane puff:
0.100 to 0.250 s
0.600 to 1.000 s

plasma for 1.67 s

j-port happy, but not e-port


Mar 29 2006 05:14:50:757PM1060329019Jim Irbydiborane puff:
0.100 to 0.250 s
1.200 to 1.500 s

plasma for 1.67 s

e-port power much better but only 1 MW
j-port looks very good again



Mar 29 2006 05:24:24:650PM1060329020Jim Irbydiborane puff:
0.100 to 0.250 s
1.200 to 1.500 s

plasma for 1.71 s

couple of e-port trips
j-port looks good

Mar 29 2006 05:39:39:410PM1060329021Jim Irbydiborane puff off

plasma for 1.94 s --- lots of h-modes

clean 3 MW of RF


Mar 29 2006 05:46:25:317PM1060329022Jim Irbydiborane puff off

plasma for 1.94 s

j-port tripped but recovered


Mar 29 2006 05:56:11:807PM1060329023Jim Irbydiborane puff off

fizzle

Mar 29 2006 06:07:04:217PM1060329024Jim Irbydiborane puff off


dud

EOT

Physics Operator Comments
Mar 29 2006 07:53:00:307AMJim Irby Rui reports:

George, Shyri and I moved the launcher position as follows:

Encoder,
Initial read out --> 1612
Final read out --> 1903
(the launcher is approx. 1.4375 inches radially out from the stop)
The recommended total compression travel is 1.5 inches.

There was no change in vessel pressure during this process,
Mar 29 2006 07:57:22:557AMJim IrbyWe are attempting to diagnose problems with ICRF transmission lines and transmitters and/or control before the run today.
Mar 29 2006 08:38:49:980AMJim IrbyCurrent ICRF status:

. arc found on #1 stubtuner/phaseshifter in the same location as found during previous fault

. j-port being conditioned but still not clear why we had trouble with retrys

. e-port should be okay


Mar 29 2006 11:37:53:543AM1060329001Jim IrbyWill start from 1060328034 --- same as 1060321011 in seg 2

Will use static fill --- 1.7e-5 request on IGT

plasma --- 3 MW of rf
Mar 29 2006 11:56:02:597AM1060329002Jim Irbynl04 request to 1.0e20/m^2 from 0.9e20/m^2

rcur from 0.6610 to 0.6580 m

plasma ---- but I increased rcur too much


Mar 29 2006 01:09:07:890PM1060329004Earl MarmarMarmar taking over as physop, Irby becomes session leader

MP 446, Intra-Shot diborane injection

Using beta version of PCS (to be able to puff diborane)

load from 1060329003

program 100 volt diborane puff from 0.75 to 1.00 seconds (segment 2, voltage output 19)

The DNB will be opening for this shot
increase prefill to 1.9e-5 (torus ion gauge)


data system problem during init
only got the chopper, no other power supplies went
PS dud
Mar 29 2006 01:20:18:677PM1060329004Jim IrbySetting up for intra-shot diborane puff

Diborane puff from 0.75 to 1.0 s
Using 20% Diborane, 80% helium bottle
Diborane regulator set to 10 psi

VUV gatevalve open
Z-Bolo shutter open
A-Port shutter open

NINJA is puffing into plasma by 1.1 s; D2 at 12 psi
DNB firing at 1.0 s

GV1 closed with bypass at 180 clicks
GV2 will be left open

Long delay was required to fix interlock on IGT that prevented it being on during the diborane puff

touble with DPCS --- only chopper supply ran
Mar 29 2006 01:49:41:017PM1060329005Earl Marmartry again. no pcs changes

plasma

no diborane puff; it appears that some interlock is disabling the system
Mar 29 2006 02:05:21:367PM1060329006Earl Marmarno pcs changes

disable vuv and DNB gate valves
close z-bolo shutter

prefill to 1.7e-5 (IGT)

plasma

got diborane this time
disrupt during rampdown
Mar 31 2006 04:56:45:830PM1060329007Earl Marmarre-enable z-bolo shutter, DNB and VUV gate valves

prefill to 1.9e-5
reduce diborane puff by 50 msec (now 100 v from .75 to .95 seconds)

plasma


Mar 29 2006 02:28:35:093PM1060329008Earl Marmarno pcs changes

plasma
disrupt in rampdown (~.5 MA)
Mar 29 2006 02:47:51:553PM1060329009Earl Marmaradd diborane puff (100 v, .2 to .3 seconds)

plasma

short h-modes, then sustained l-mode, 3 MW RF
Mar 29 2006 03:05:31:560PM1060329010Earl Marmarmove second diborane puff, now 1.0 to 1.5 seconds; first puff unchanged

plasma
steady 3 MW rf
barely in and out of h-mode
disrupted earlier in rampdown (800 kA)
Mar 29 2006 03:17:52:540PM1060329011Earl Marmarmove first diborane puff earlier (now .15 to .25 seconds)

reduce second puff by 100 msec (now 1.0 to 1.4 seconds)

plasma
3 MW steady rf; tiny, dithery h-modes
Mar 29 2006 03:30:58:107PM1060329012Earl Marmarstart first diborane puff earlier (now .1 to .25 seconds); second puff unchanged

plasma
3 MW steady rf
Mar 29 2006 03:45:25:567PM1060329013Earl Marmarno pcs changes

plasma
similar to 12

Zeff ~ 2 straight across the shot
Mar 31 2006 04:57:24:783PM1060329014Earl Marmardisable diborane puffs (at the PLC)

plasma

Mar 29 2006 04:09:22:560PM1060329015Earl Marmarno changes

plasma

similar to 14, but J-port tripped late
Mar 29 2006 04:22:29:130PM1060329016Earl Marmardiborane back on
2 puffs: 0.1 to 0.35 seconds, 1.0 to 1.3 seconds

early disruption (0.4 seconds); will have to back off on the early puff.

lost an oh breaker on the disruption; power room access required to reset the power supply
Mar 29 2006 04:41:24:400PM1060329017Earl Marmarreduce early diborane puff

puffs are now: 0.1 to 0.25 seconds, and 1.0 to 1.3 seconds

plasma
similar to earlier shots with diborane; very short h-modes
3 MW steady rf power
Mar 29 2006 04:53:52:470PM1060329018Earl Marmarmove second diborane puff, and lengthen.

Puffs at: 0.1 to 0.25 seconds, and 0.6 to 1.0 seconds

plasma
no obvious h-mode at all
Mar 29 2006 05:28:06:217PM1060329019Earl Marmarmove second diborane puff.
Puffs are: 0.1 to 0.25 seconds, and 1.2 to 1.5 seconds

plasma
Mar 29 2006 05:27:21:123PM1060329020Earl Marmarrepeat

plasma
similar results
Mar 29 2006 05:28:27:187PM1060329021Earl Marmardiborane puffs off

plasma
Mar 29 2006 05:42:52:690PM1060329022Earl Marmarrepeat; diborane puffs still off

plasma
Mar 29 2006 05:55:22:493PM1060329023Earl Marmarno changes

fizzle
Mar 29 2006 06:07:02:980PM1060329024Earl Marmarno changes

dud

last attempt of the day

Engineering Operator Comments
ShotTimeTypeStatusComment
111:27:15:633AMPlasmaOk
211:47:14:907AMPlasmaOk
312:01:54:833PMPlasmaOk
401:01:49:513PMPlasmaBadTop Hybrid Hardware Init Act Fault
501:41:49:763PMPlasmaOk
601:54:40:707PMPlasmaOk
702:09:02:743PMPlasmaOk
802:22:39:170PMPlasmaOk
902:37:06:753PMPlasmaOk
1002:53:05:870PMPlasmaOk
1103:06:32:577PMPlasmaOk
1203:20:00:590PMPlasmaOk
1303:33:12:610PMPlasmaOk
1403:46:40:210PMPlasmaOk
1503:59:36:040PMPlasmaOk
1604:13:00:843PMPlasmaOk
1704:28:56:303PMPlasmaOk
1804:42:23:700PMPlasmaOk
1905:00:00:690PMPlasmaOk
2005:13:12:617PMPlasmaOk
2105:25:54:513PMPlasmaOk
2205:38:21:610PMPlasmaOk
2305:50:59:427PMPlasmaOk
2406:03:50:527PMPlasmaOk