Alcator C-Mod Run 950512 Information

Miniproposals

Miniproposal: 113

Date Filed: 4/13/1995

Title: Impurity Puffing to Induce the Detached Divertor Condition in

First Author: Steve Golovato

Session Leader: John Goetz (shots 1-33)

Operators
Session leader(s):	John Goetz
Physics operator(s):	Joseph Snipes
Engineering operator(s):	Vinny Bertolino

Engineering Operator Run Comment
silva set up

Session Leader Plans

Physics Operators Plans

Session Leader Summaries

Physics Operator Summaries

Entered: Jul 7 2004 04:36:54:207PM

Author: To Be Determined

MP 113 RF detachment run with impurity puffing
Engineer in Charge: Vince Bertolino
Physics Operator: Joseph Snipes
Session Leader: John Goetz

The plan is to try to induce detachment by puffing Ne or CH4 into
an RF heated plasma. Standard conditions, 5.3 T, 0.8 MA, nel set to 1.2 x
10^20 m^-2. Copied shot 950509013 except for higher density. Prefill set
to 2.0 x 10^-5 Torr.

Overall, it was quite a good run. There were 30 shots, 28 plasmas,
1 fizzle, and one no TF shot. A number of the earlier shots went into
H-mode with the RF with H factors of 1.4 or so. Detachment occurred on a
number of shots with and without methane with RF. Two shots were lost due
to some strange data acquisition problems, shot 6 lost some crucial
magnetic coils so that EFIT could not run and shot 30 lost most of the
data. There were no shots with H-mode and detachment at the same time.

Shot 1: Fizzle!
2: Prefill set to 1.7 x 10^-5 Torr. Good shot.
3: Changed to FSP controller. Good shot.
4: Increased gain at 0.506 sec on FSP controller to 8. ICRF
H-modes from 0.64 - 0.7, 0.75 - 0.8, 0.92 - 0.99 sec. with 1.5 MW
5: 20 ms Ne puff at 0.9 s. Good shot. ELM-free H-modes 0.63 - 0.7,
0.73 - 0.78, and ELMy 0.8 - 1.0 sec.
6: 40 ms Ne puff at 0.85 s. Good shot.ICRF H-modes from 0.65 -
0.76 and 0.83 - 0.89 sec. EFIT problems.
7: Repeat. Good shot.RF H-modes from 0.64 - 0.7 and 0.78 - 0.91 sec.
8: 60 ms Ne puff at 0.825 s. Good shot. H-mode 0.63 - 0.9,
ELM-free until 0.7, then ELMy.
9: Neon puffs at 0.7, 0.8, and 0.9 s each for 20 ms. Good shot.
Short ELM-free H-modes 0.63 - 0.7, then ELMy from 0.7 - 1.0
with a short L phase around 0.85 s.
10: nel set to 1.5 x 10^20 m^-2. No TF.
11: Repeat. Disrupted at 0.46 sec. Large Moly injection.
12: Good shot. ELM-free and ELMy H-modes in and out throughout the
RF pulse from 0.63 to 1.05 sec.
13: Increased outer gap. Good shot. In and out of ELMy and
ELM-free H-mode form 0.63 to 1.05 sec.
14: Good shot. RF down to 1 MW. No H-mode, but some dithering.
15: Neon puffs at 0.7, 0.8, 0.9 for 20 ms each. Disrupted at 1.13 s.
16: Turned off neon puff at 0.9 s and made puffs at 0.7 and 0.8 40
msec each. Disrupted at 0.9 sec. Too much neon.
17: Turned off neon. Good shot.Disrupted in rampdown at 1.29 sec.
Not enough RF power to sustain the sharkfin (only 1 MW).
18: Methane puff from 0.7 to 0.9 sec at 100 V and 3 psi. Good shot.
19: Raised pressure of methane to 5 psi. Good shot.
20: Methane puff 0.8 - 1 sec. Good shot.
21: Deuterium pressure to 22.4 psi, methane from 0.65 - 0.85 sec.
FSP set to -1.75 cm during flattop. Disrupted at 0.64 sec.
22: FSP set to -1.25 cm during the flattop. Good shot.
23: Increase RF power. Good shot. ELMy RF H-mode 0.72 - 0.82 s.
24: Methane at 7 psi. Good shot. Dithering from 0.73 - 1.03 sec.
25: Methane at 9 psi from 0.65 - 0.95 s. Dithering from 0.73 -
0.87 sec.
26: Repeat. Good shot.
27: Repeat. Good shot.
28: Enabled the NINJA gas system with 21 psi of deuterium. NINJA
puff from 0.5 for 80 ms, expecting a 70 ms delay before the gas
gets into the plasma. Raising the density to 1.8 x 10^20 m^-3.
Good shot. NINJA did not inject.
29: NINJA puff for 80 ms from 0.5 s and methane puff 0.65 - 0.85 s.
Good shot. Disrupted at 1.0 sec.
30: Reduce methane pressure to 5 psi. Disrupted at 0.63 sec.
Computer errors.

Session Leader Comments

May 12 1995 08:13:35:050AM John Goetz Run Plan for 950512 - MP#113 (Impurity Puffing to Induce
the Dectached Divertor Condition in High Power RF Discharges)

Startup:
Run with Bt=5.3T
ECDC in deuterium
A_SIDE with 20PSIA of deuterium; B_SIDE_LOWER with 3PSIA of neon
Load shot 950509013 (keep 950405022 in reserve for FSP control)
try to hold RXL constant @ 0.56 throughout the diverted phase
NL04 = 1.2e20

(1) Obtain a plasma acceptable to both the EDGE and RF groups; gaps
approximately 2cm and DSEP,SSEP > 1.5cm
Begin with STRKPSI-RXL control just to obtain a plasma but
switch to FSP-RXL control (see 950405022) as soon as possible
Check strike points - lower FSP as necessary
Tune RF for approx. 1MW injected power - pulse length from 0.6 to 1.0sec
Make sure the plasma is attached - verified with FSP

May 12 1995 08:14:11:340AM John Goetz (2) Puff neon through B_SIDE_LOWER (forgoes argon-based measurements for
the day) or through capillary tube B30-007
If necessary, use multiple puffs per shot in order to conserve shots
Monitor the neon in the divertor with the Chromex; neon in the
core plasma with the McPherson (Li-like Ne @ 750A)
Monitor the power flowing in the SOL (core radiated power) and the radiation
pattern in the divertor region
Fire FSP (if target acceptable)
Increase the amount of neon puffed until detachment occurs - verified
by the FSP profiles if possible - at the threshold, look for H-mode
conditions

(3) Tune RF for approx. 2MW injected power - pulse length from 0.6 to 1.0sec
Make sure plasma is attached - verified with FSP
Repeat step 2.

(4) Tune RF for maximum power this day (hopefully near 3MW) - pulse length
from 0.6 to 1.0sec
Make sure plasma is attached - verified with FSP
Repeat step 2.

May 12 1995 08:18:01:920AM John Goetz (5) Repeat steps (2) - (4) with methane puffing
Replace neon with carbon in the preceeding instructions
McPherson looking at H-like and He-like carbon

(Contingency) If time, repeat conditions for which H-modes seemed most
favorable and fiddle around a bit.

Goals:
(1) Determine the amount and type of puffed impurities required for
divertor detachment at high RF powers.

(2) Survey the conditions under which H-modes and divertor detachment
exist to see if they can be made compatible.

May 12 1995 05:39:41:440PM John Goetz Did methane puffs after the run thru "b side lower" to calibrate
the valve (used 3, 5, 7, and 9 PSI)

May 12 1995 08:38:53:390AM 950512001 John Goetz Shot 950512001
Fizzle

May 12 1995 09:01:03:780AM 950512002 John Goetz Shot 950512002
Plasma - gaps o.k. - SSEP o.k.
Prf = 1.0 -> 0.8MW
Looks something like a divertor detachment @ 0.9sec

May 12 1995 09:22:16:220AM 950512003 John Goetz Shot 950512003
Using FSP controller to get a good target
plasma - target o.k. from 0.7 to 1.0
Prf = 1.2->1.0MW
DR @ 0.9sec - o.strike between 5 & 6 - i.strike @ 3
divertor appears to be attached

May 12 1995 09:43:29:100AM 950512004 John Goetz Shot 950512004
plasma - 3 H-mode transitions
Prf=1.4MW - Psol up to 1.5MW (but jumping around)
o.strike = probe 5; i.strike = probe 3
divertor is attached

May 12 1995 10:02:47:990AM 950512005 John Goetz Shot 950512005
(.02sec x 100V) puff of neon at 0.9sec
plasma - 3 H-modes - ELMy H-mode from 0.8 to 1.0
o.strike = probe 5; i.strike @ probe 3
FSP target only good after 0.7sec
divertor attached

May 12 1995 10:23:23:100AM 950512006 John Goetz Shot 950512006
(.04sec x 100V) puff of neon at 0.85sec
plasma - 2 H-modes - neon terminates the dithering at the end
no EFIT, so we're flying blind

May 12 1995 10:59:57:510AM 950512007 John Goetz Shot 950512007
(.04s x 100V) neon puff @ 0.85
plasma - no signs of divertor detachment
2 H-modes (second one ELMy); neon stops the H-mode
Prf = 1.4MW; Psol = 1.5MW

May 12 1995 11:00:58:650AM 950512008 John Goetz Shot 950512008:
(.06s x 100V) neon puff @ 0.85
plasma - low temperature @ probe 5 (the strike point) when
the neon gets in
1 H-mode (ELM free and ELMy); neon stops the H-mode
Prf = 1.5MW; Psol = 1.5MW

May 12 1995 11:18:43:540AM 950512009 John Goetz Shot 950512009:
(.02s x 100V) neon puff @ 0.7, 0.8, and 0.9sec
plasma -
Prf=1.6MW; Psol=1.0 -> 1.5MW
no signs of detachment - there is neon in the main plasma
and Zeff is rising with the puffs

May 12 1995 11:23:28:480AM 950512010 John Goetz Shot 950512010:
dud - no TF

May 12 1995 11:23:44:190AM 950512010 John Goetz Shot 950512010:
dud - no TF

May 12 1995 11:52:32:040AM 950512011 John Goetz Shot 950512011:
NL04 = 1.5e20; no neon puff
plasma - disrupts @ 0.46 due to large Mo injection @ 0.44

May 12 1995 12:01:49:280PM 950512012 John Goetz Shot 950512012:
NL04 = 1.5e20; no neon puff
plasma - many H->L->H transitions
Prf = 1.5MW; Psol=0.8MW

May 12 1995 12:13:46:920PM 950512013 John Goetz Shot 950512013:
plasma - many H->L->H transitions
Prf = 1.3 -> 1.4MW; Psol = 0.7Mw

May 12 1995 01:01:41:220PM 950512014 John Goetz Shot 950512014:
plasma - some dithering - no H-mode
Prf = 1.0MW; Psol = 1.3 -> 1.0MW
detachment is difficult to diagnose as the strike point is
moving late in the shot

May 12 1995 01:03:53:680PM 950512015 John Goetz Shot 950512015:
(.02s x 100V) neon @ 0.7, 0.8, 0.9sec
plasma - no H-mode
Prf = 1.0MW -> 0.4MW; Psol = 1.2 -> 1.0MW
divertor detaches near the end of the discharge

May 12 1995 01:05:46:100PM 950512016 John Goetz Shot 950512016:
(.04s x 100V) neon @ 0.7, 0.8sec
plasma - no H-mode
disrupts due to neon accumulation
divertor detaches before the disruption

May 12 1995 01:10:16:590PM 950512017 John Goetz Shot 950512017:
no impurities
plasma - o.k. shot

May 12 1995 05:22:53:800PM 950512019 John Goetz Shot 950512019:
plasma - (.2s x 100V) 5 PSIA methane @ 0.7 - 0.9 sec
CVI peaks at .85 sec - sig 11.x10^14 ph/s/cm^2/st) - plasma detached
at on probes 6 and 7.

May 12 1995 05:27:57:970PM 950512020 John Goetz Shot 950512020:
plasma - (.2s x 100V) 5 PSIA methane @ 0.7 - 0.9 sec
CVI peaks at .85 sec - sig 11.x10^14 ph/s/cm^2/st) - plasma detached
at on probes 6 and 7.

May 12 1995 05:28:48:940PM 950512021 John Goetz Shot 950512021:
plasma disrupted at 0.64 sec -
programming was (.2s x 100V) 5 PSIA methane @ 0.65 - 1.0 sec

May 12 1995 05:33:23:700PM 950512022 John Goetz Shot 950512022:
plasma - (.2s x 100V) 5 PSIA methane @ 0.65 - 0.85 sec
CVI peaks at .8 sec - sig 12. (x10^14 ph/s/cm^2/st) - plasma detached
before the RF, the RF (1MW) then attaches it, but the CH4 then
detaches it again.

May 12 1995 05:34:08:610PM 950512023 John Goetz Shot 950512023:
plasma - (.2s x 100V) 5 PSIA methane @ 0.65 - 0.85 sec
got 2 MW from 0.7 to .85 s
CVI peaks at .85 sec with sig - 12. (x10^14 ph/s/cm^2/st) -
plasma detached before the RF, the RF attaches it; it does not
detach during the 2 MW of RF.

May 12 1995 05:34:32:330PM 950512024 John Goetz Shot 950512024:
plasma - (.2s x 100V) 7 PSIA methane @ 0.65 - 0.85 sec
got 2 MW from 0.7 to 1.0 s
CVI peaks at .85 sec with sig 16. (x10^14 ph/s/cm^2/st) -
plasma detached before the RF, the RF attaches it;
possible detachment on probe 5 late in the RF pulse.

May 12 1995 05:34:54:640PM 950512025 John Goetz Shot 950512025:
plasma - (.3s x 100V) 9 PSIA methane @ 0.65 - 0.95 sec
got 2 MW from 0.7 to 0.92 s
CVI peaks at .9 sec with sig 22. (x10^14 ph/s/cm^2/st) -
plasma detached before the RF, the RF attaches it;
definite detachment thru probe 7 late in the 2 MW RF pulse.

May 12 1995 05:35:23:100PM 950512026 John Goetz Shot 950512026:
plasma - (.3s x 100V) 9 PSIA methane @ 0.65 - 0.95 sec
got 2 MW from 0.7 to 0.90 s
CVI peaks at .85 sec - with sig 21 (x10^14 ph/s/cm^2/st) -
plasma detached before the RF, the RF attaches it; then
definite detachment thru probe 7 late in the 2 MW RF pulse.

May 12 1995 05:35:55:160PM 950512027 John Goetz Shot 950512027:
plasma - (.3s x 100V) 9 PSIA methane @ 0.65 - 0.95 sec
got 2 MW from 0.7 to 0.95 s
Trophy shot for detachment at 2 MW.
CVI peaks at .85 sec - with sig 21 (x10^14 ph/s/cm^2/st) -
plasma detached before the RF, the RF attaches it; then
definite detachment thru probe 7 later in the 2 MW RF pulse.
Radiated power outside the LCFS just before @ MW detachment
is 1.1 MW; it then falls at detachment with the radiation
moving inside the LCFS

May 12 1995 05:36:21:010PM 950512028 John Goetz Shot 950512028:
plasma - disrupted at 1.0
puffed gas (.3s x 100V) 8.9 PSIA methane @ 0.65 - 0.95 sec
got 2 MW from 0.7 to 0.83 s.
Plasma detached before RF and never really attaches.
CVI brightness = 16 (x10^14 ph/s/cm^2/st)

May 12 1995 05:37:33:320PM 950512029 John Goetz Shot 950512029:
plasma - disrupted at 1.0
puffed gas (.3s x 100V) 8.9 PSIA methane @ 0.65 - 0.95 sec
got 2 MW from 0.7 to 0.83 s.
Plasma detached before RF and never really attaches.
CVI brightness = 16 (x10^14 ph/s/cm^2/st)

May 12 1995 05:37:53:270PM 950512030 John Goetz Shot 950512030:
plasma - disrupted at 1.63 - many data system problems
we had lowered the methane plenum press. in an attempt
to find detachment threshold at nl04=1.8x10^20.

Physics Operator Comments

May 12 1995 08:31:02:440AM Joseph Snipes MP 113 RF detachment run with impurity puffing
Engineer in Charge: Vince Bertolino
Physics Operator: Joseph Snipes
Session Leader: John Goetz

The plan is to try to induce detachment by puffing Ne or CH4 into an RF heated
plasma. Standard conditions, 5.3 T, 0.8 MA, nel set to 1.2 x 10^20 m^-2.
Copied shot 950509013 except for higher density. Prefill set to 2.0 x 10^-5
Torr.

May 12 1995 08:42:36:680AM 950512001 Joseph Snipes Shot 1
Fizzle!

May 12 1995 08:59:56:630AM 950512002 Joseph Snipes Shot 2
Prefill set to 1.7 x 10^-5 Torr. Good shot.

May 12 1995 09:16:23:950AM 950512003 Joseph Snipes Shot 3
Copied wire 9 FSP controller into wire 9 from shot 950405022 segment 2. Then,
copied RXL and ZXL gains and waveforms from the same shot and turned off
STRKPSI controller. Good shot.

May 12 1995 09:33:22:390AM 950512004 Joseph Snipes Shot 4
Increased gain on FSP controller from 0.506 sec to 8. Good shot. ICRF H-modes
from 0.64 - 0.7, 0.75 - 0.8, 0.92 - 0.99 sec.

May 12 1995 09:59:37:740AM 950512005 Joseph Snipes Shot 5
Put RXU to zero during the flattop to try to save power on EF2 at Horne's
suggestion. Enabled pulse gas 1, neon, with a 20 ms, 100 V pulse starting at
0.9 sec. Good shot. ICRF H-modes from 0.6 to 1 sec. ELMy from 0.8 - 1.0 sec.

May 12 1995 10:24:06:550AM 950512006 Joseph Snipes Shot 6
Made RXU -1.5 cm opposite to previous shot, again at Horne's suggestion.
Neon puff at 0.85 sec for 40 ms. Good shot. ICRF H-modes from 0.65 - 0.76 and
0.83 - 0.89 sec.

May 12 1995 10:31:18:700AM 950512007 Joseph Snipes Shot 7
Repeat. Good shot. RF H-modes from 0.64 - 0.7 and 0.78 - 0.91 sec.

May 12 1995 10:58:46:630AM 950512008 Joseph Snipes Shot 8
Added step in FSP controller signal up by 5 mm from 0.5 to 0.75 sec. Neon
puff starting at 0.825 sec for 60 msec. Good shot. H-mode 0.63 - 0.9, ELM-free
until 0.7, then ELMy.

May 12 1995 11:19:02:370AM 950512009 Joseph Snipes Shot 9
Neon puffs at 0.7, 0.8, and 0.9 s each for 20 ms. Good shot. Short ELM-free
H-modes 0.63 - 0.7, then ELMy from 0.7 - 1.0 with a short L phase around 0.85 s.

May 12 1995 11:24:13:440AM 950512010 Joseph Snipes Shot 10
Density raised to nel = 1.5 x 10^20 m^-2. No TF.

May 12 1995 11:38:46:500AM 950512011 Joseph Snipes Shot 11
Density raised to nel = 1.5 x 10^20 m^-2. Disrupted at 0.46 sec. Large Moly
injection.

May 12 1995 11:57:18:820AM 950512012 Joseph Snipes Shot 12
Try again. Good shot. ELM-free and ELMy H-modes in and out throughout the
RF pulse from 0.63 to 1.05 sec.

May 12 1995 12:23:45:150PM 950512013 Joseph Snipes Shot 13
RCUR moved in by 2 mm from 0.6 sec to 1.0 sec to increase the outer gap.
Good shot. In and out of ELMy and ELM-free H-mode form 0.63 to 1.05 sec.

May 12 1995 12:24:54:430PM 950512014 Joseph Snipes Shot 14
Good shot. RF down to 1 MW. No H-mode, but some dithering.

May 12 1995 12:44:30:520PM 950512015 Joseph Snipes Shot 15
Took out step in FSP controller. Increased density ramp rate between 0.5 and
0.6 sec. Turned on neon puffs at 0.7, 0.8, and 0.9 for 20 msec each.
Disrupted at 1.13 sec. Apparently too much neon.

May 12 1995 01:01:03:750PM 950512016 Joseph Snipes Shot 16
Turned off neon puff at 0.9 s and made puffs at 0.7 and 0.8 40 msec each.
Disrupted at 0.9 sec. Still too much neon.

May 12 1995 01:29:50:900PM 950512017 Joseph Snipes Shot 17
Turned off neon. Good shot. Disrupted in rampdown at 1.29 sec.
Not enough RF power to sustain the sharkfin (only 1 MW).

May 12 1995 01:27:50:210PM 950512018 Joseph Snipes Shot 18
Methane puff from 0.7 to 0.9 sec at 100 V and 3 psi. Good shot.

May 12 1995 01:41:38:580PM 950512019 Joseph Snipes Shot 19
Raised pressure of methane to 5 psi. Good shot.

May 12 1995 01:52:35:120PM 950512020 Joseph Snipes Shot 20
Methane puff shifted to start at 0.8 sec and end at 1 sec. Good shot.

May 12 1995 02:17:19:930PM 950512021 Joseph Snipes Shot 21
Raised pressure on A side deuterium plenum to 22 psi. Moved methane puff to
start at 0.65 sec and end at 0.85 sec. FSP set to -1.75 cm during
flattop. Disrupted at 0.64 sec. EF2 railed. It seems that the elongation
increased too much because of the drop in the FSP controller.

May 12 1995 02:20:34:480PM 950512022 Joseph Snipes Shot 22
FSP set to -1.25 cm during the flattop. Good shot.

May 12 1995 02:47:40:900PM 950512023 Joseph Snipes Shot 23
Increase RF power. Good shot. ELMy RF H-mode from 0.72 - 0.82 sec.

May 12 1995 03:05:13:010PM 950512024 Joseph Snipes Shot 24
Increase methane plenum pressure to 7 psi. Good shot. No H-mode. Dithering
from 0.73 - 1.03 sec.

May 12 1995 03:34:27:290PM 950512025 Joseph Snipes Shot 25
Increase methane plenum pressure to 9 psi and puff from 0.65 - 0.95 s.
Good shot. No H-mode. Dithering from 0.73 - 0.87 sec.

May 12 1995 03:47:34:880PM 950512026 Joseph Snipes Shot 26
Repeat. Good shot.

May 12 1995 04:27:04:150PM 950512028 Joseph Snipes Shot 28
Enabled the NINJA gas system with 21 psi of deuterium. NINJA puff from 0.5
for 80 ms, expecting a 70 ms delay before the gas gets into the plasma. Raising
the density to 1.8 x 10^20 m^-3. Good shot. NINJA did not inject.

May 12 1995 04:44:24:630PM 950512029 Joseph Snipes Shot 29
Try NINJA puff again for 80 ms from 0.5 s and methane puff 0.65 - 0.85 s.
Good shot. Disrupted at 1.0 sec.

May 12 1995 05:09:44:410PM 950512030 Joseph Snipes Shot 30
Reduced methane pressure to 5 psi. Disrupted at 0.63 sec. Computer errors.

Engineering Operator Comments

Shot Time Type Status Comment

1 05:54:49:710AM Plasma Ok

2 08:41:33:570AM Plasma Ok

3 09:01:03:930AM Plasma Ok

4 09:18:54:550AM Plasma Ok No Faults.

5 09:43:11:830AM Plasma Ok comm fault oh2l after fizzle detector

6 10:02:25:310AM Plasma Ok

7 10:23:18:100AM Plasma Ok

8 10:41:46:010AM Plasma Ok

9 11:00:35:680AM Plasma Ok

10 11:18:24:760AM Plasma Bad no tf

11 11:29:46:010AM Plasma Ok

12 11:41:46:700AM Plasma Ok comm faults after the fizzle detector

13 11:57:57:680AM Plasma Ok comm fault after disruption

14 12:11:41:750PM Plasma Ok

15 12:26:43:800PM Plasma Ok

16 12:46:07:110PM Plasma Ok

17 12:59:48:810PM Plasma Ok No Faults.

18 01:16:04:500PM Plasma Ok No Faults.

19 01:31:36:020PM Plasma Ok No Faults.

20 01:48:21:570PM Plasma Ok No Faults.

21 02:01:40:920PM Plasma Ok No Faults.

22 02:16:51:990PM Plasma Ok comm fault OH1, OH2L, & EF1U

23 02:35:46:650PM Plasma Ok No Faults.

24 02:56:17:890PM Plasma Ok No Faults.

25 03:22:43:470PM Plasma Ok No Faults.

26 03:33:35:100PM Plasma Ok Comm fault OH1, OH2L,&ef1U

27 03:51:58:950PM Plasma Ok No Faults.

28 04:22:03:620PM Plasma Ok Comm Fault OH2L,OH1, EF1U

29 04:35:52:070PM Plasma Ok NO Faults.

30 05:04:13:240PM Plasma Ok No Faults.

31 05:38:40:480PM Test Ok

32 05:53:16:780PM Test Ok

33 06:03:48:100PM Test Ok punt

Session Leader Comments
May 12 1995 08:13:35:050AM		John Goetz	Run Plan for 950512 - MP#113 (Impurity Puffing to Induce the Dectached Divertor Condition in High Power RF Discharges) Startup: Run with Bt=5.3T ECDC in deuterium A_SIDE with 20PSIA of deuterium; B_SIDE_LOWER with 3PSIA of neon Load shot 950509013 (keep 950405022 in reserve for FSP control) try to hold RXL constant @ 0.56 throughout the diverted phase NL04 = 1.2e20 (1) Obtain a plasma acceptable to both the EDGE and RF groups; gaps approximately 2cm and DSEP,SSEP > 1.5cm Begin with STRKPSI-RXL control just to obtain a plasma but switch to FSP-RXL control (see 950405022) as soon as possible Check strike points - lower FSP as necessary Tune RF for approx. 1MW injected power - pulse length from 0.6 to 1.0sec Make sure the plasma is attached - verified with FSP
May 12 1995 08:14:11:340AM		John Goetz	(2) Puff neon through B_SIDE_LOWER (forgoes argon-based measurements for the day) or through capillary tube B30-007 If necessary, use multiple puffs per shot in order to conserve shots Monitor the neon in the divertor with the Chromex; neon in the core plasma with the McPherson (Li-like Ne @ 750A) Monitor the power flowing in the SOL (core radiated power) and the radiation pattern in the divertor region Fire FSP (if target acceptable) Increase the amount of neon puffed until detachment occurs - verified by the FSP profiles if possible - at the threshold, look for H-mode conditions (3) Tune RF for approx. 2MW injected power - pulse length from 0.6 to 1.0sec Make sure plasma is attached - verified with FSP Repeat step 2. (4) Tune RF for maximum power this day (hopefully near 3MW) - pulse length from 0.6 to 1.0sec Make sure plasma is attached - verified with FSP Repeat step 2.
May 12 1995 08:18:01:920AM		John Goetz	(5) Repeat steps (2) - (4) with methane puffing Replace neon with carbon in the preceeding instructions McPherson looking at H-like and He-like carbon (Contingency) If time, repeat conditions for which H-modes seemed most favorable and fiddle around a bit. Goals: (1) Determine the amount and type of puffed impurities required for divertor detachment at high RF powers. (2) Survey the conditions under which H-modes and divertor detachment exist to see if they can be made compatible.
May 12 1995 05:39:41:440PM		John Goetz	Did methane puffs after the run thru "b side lower" to calibrate the valve (used 3, 5, 7, and 9 PSI)
May 12 1995 08:38:53:390AM	950512001	John Goetz	Shot 950512001 Fizzle
May 12 1995 09:01:03:780AM	950512002	John Goetz	Shot 950512002 Plasma - gaps o.k. - SSEP o.k. Prf = 1.0 -> 0.8MW Looks something like a divertor detachment @ 0.9sec
May 12 1995 09:22:16:220AM	950512003	John Goetz	Shot 950512003 Using FSP controller to get a good target plasma - target o.k. from 0.7 to 1.0 Prf = 1.2->1.0MW DR @ 0.9sec - o.strike between 5 & 6 - i.strike @ 3 divertor appears to be attached
May 12 1995 09:43:29:100AM	950512004	John Goetz	Shot 950512004 plasma - 3 H-mode transitions Prf=1.4MW - Psol up to 1.5MW (but jumping around) o.strike = probe 5; i.strike = probe 3 divertor is attached
May 12 1995 10:02:47:990AM	950512005	John Goetz	Shot 950512005 (.02sec x 100V) puff of neon at 0.9sec plasma - 3 H-modes - ELMy H-mode from 0.8 to 1.0 o.strike = probe 5; i.strike @ probe 3 FSP target only good after 0.7sec divertor attached
May 12 1995 10:23:23:100AM	950512006	John Goetz	Shot 950512006 (.04sec x 100V) puff of neon at 0.85sec plasma - 2 H-modes - neon terminates the dithering at the end no EFIT, so we're flying blind
May 12 1995 10:59:57:510AM	950512007	John Goetz	Shot 950512007 (.04s x 100V) neon puff @ 0.85 plasma - no signs of divertor detachment 2 H-modes (second one ELMy); neon stops the H-mode Prf = 1.4MW; Psol = 1.5MW
May 12 1995 11:00:58:650AM	950512008	John Goetz	Shot 950512008: (.06s x 100V) neon puff @ 0.85 plasma - low temperature @ probe 5 (the strike point) when the neon gets in 1 H-mode (ELM free and ELMy); neon stops the H-mode Prf = 1.5MW; Psol = 1.5MW
May 12 1995 11:18:43:540AM	950512009	John Goetz	Shot 950512009: (.02s x 100V) neon puff @ 0.7, 0.8, and 0.9sec plasma - Prf=1.6MW; Psol=1.0 -> 1.5MW no signs of detachment - there is neon in the main plasma and Zeff is rising with the puffs
May 12 1995 11:23:28:480AM	950512010	John Goetz	Shot 950512010: dud - no TF
May 12 1995 11:23:44:190AM	950512010	John Goetz	Shot 950512010: dud - no TF
May 12 1995 11:52:32:040AM	950512011	John Goetz	Shot 950512011: NL04 = 1.5e20; no neon puff plasma - disrupts @ 0.46 due to large Mo injection @ 0.44
May 12 1995 12:01:49:280PM	950512012	John Goetz	Shot 950512012: NL04 = 1.5e20; no neon puff plasma - many H->L->H transitions Prf = 1.5MW; Psol=0.8MW
May 12 1995 12:13:46:920PM	950512013	John Goetz	Shot 950512013: plasma - many H->L->H transitions Prf = 1.3 -> 1.4MW; Psol = 0.7Mw
May 12 1995 01:01:41:220PM	950512014	John Goetz	Shot 950512014: plasma - some dithering - no H-mode Prf = 1.0MW; Psol = 1.3 -> 1.0MW detachment is difficult to diagnose as the strike point is moving late in the shot
May 12 1995 01:03:53:680PM	950512015	John Goetz	Shot 950512015: (.02s x 100V) neon @ 0.7, 0.8, 0.9sec plasma - no H-mode Prf = 1.0MW -> 0.4MW; Psol = 1.2 -> 1.0MW divertor detaches near the end of the discharge
May 12 1995 01:05:46:100PM	950512016	John Goetz	Shot 950512016: (.04s x 100V) neon @ 0.7, 0.8sec plasma - no H-mode disrupts due to neon accumulation divertor detaches before the disruption
May 12 1995 01:10:16:590PM	950512017	John Goetz	Shot 950512017: no impurities plasma - o.k. shot
May 12 1995 05:22:53:800PM	950512019	John Goetz	Shot 950512019: plasma - (.2s x 100V) 5 PSIA methane @ 0.7 - 0.9 sec CVI peaks at .85 sec - sig 11.x10^14 ph/s/cm^2/st) - plasma detached at on probes 6 and 7.
May 12 1995 05:27:57:970PM	950512020	John Goetz	Shot 950512020: plasma - (.2s x 100V) 5 PSIA methane @ 0.7 - 0.9 sec CVI peaks at .85 sec - sig 11.x10^14 ph/s/cm^2/st) - plasma detached at on probes 6 and 7.
May 12 1995 05:28:48:940PM	950512021	John Goetz	Shot 950512021: plasma disrupted at 0.64 sec - programming was (.2s x 100V) 5 PSIA methane @ 0.65 - 1.0 sec
May 12 1995 05:33:23:700PM	950512022	John Goetz	Shot 950512022: plasma - (.2s x 100V) 5 PSIA methane @ 0.65 - 0.85 sec CVI peaks at .8 sec - sig 12. (x10^14 ph/s/cm^2/st) - plasma detached before the RF, the RF (1MW) then attaches it, but the CH4 then detaches it again.
May 12 1995 05:34:08:610PM	950512023	John Goetz	Shot 950512023: plasma - (.2s x 100V) 5 PSIA methane @ 0.65 - 0.85 sec got 2 MW from 0.7 to .85 s CVI peaks at .85 sec with sig - 12. (x10^14 ph/s/cm^2/st) - plasma detached before the RF, the RF attaches it; it does not detach during the 2 MW of RF.
May 12 1995 05:34:32:330PM	950512024	John Goetz	Shot 950512024: plasma - (.2s x 100V) 7 PSIA methane @ 0.65 - 0.85 sec got 2 MW from 0.7 to 1.0 s CVI peaks at .85 sec with sig 16. (x10^14 ph/s/cm^2/st) - plasma detached before the RF, the RF attaches it; possible detachment on probe 5 late in the RF pulse.
May 12 1995 05:34:54:640PM	950512025	John Goetz	Shot 950512025: plasma - (.3s x 100V) 9 PSIA methane @ 0.65 - 0.95 sec got 2 MW from 0.7 to 0.92 s CVI peaks at .9 sec with sig 22. (x10^14 ph/s/cm^2/st) - plasma detached before the RF, the RF attaches it; definite detachment thru probe 7 late in the 2 MW RF pulse.
May 12 1995 05:35:23:100PM	950512026	John Goetz	Shot 950512026: plasma - (.3s x 100V) 9 PSIA methane @ 0.65 - 0.95 sec got 2 MW from 0.7 to 0.90 s CVI peaks at .85 sec - with sig 21 (x10^14 ph/s/cm^2/st) - plasma detached before the RF, the RF attaches it; then definite detachment thru probe 7 late in the 2 MW RF pulse.
May 12 1995 05:35:55:160PM	950512027	John Goetz	Shot 950512027: plasma - (.3s x 100V) 9 PSIA methane @ 0.65 - 0.95 sec got 2 MW from 0.7 to 0.95 s Trophy shot for detachment at 2 MW. CVI peaks at .85 sec - with sig 21 (x10^14 ph/s/cm^2/st) - plasma detached before the RF, the RF attaches it; then definite detachment thru probe 7 later in the 2 MW RF pulse. Radiated power outside the LCFS just before @ MW detachment is 1.1 MW; it then falls at detachment with the radiation moving inside the LCFS
May 12 1995 05:36:21:010PM	950512028	John Goetz	Shot 950512028: plasma - disrupted at 1.0 puffed gas (.3s x 100V) 8.9 PSIA methane @ 0.65 - 0.95 sec got 2 MW from 0.7 to 0.83 s. Plasma detached before RF and never really attaches. CVI brightness = 16 (x10^14 ph/s/cm^2/st)
May 12 1995 05:37:33:320PM	950512029	John Goetz	Shot 950512029: plasma - disrupted at 1.0 puffed gas (.3s x 100V) 8.9 PSIA methane @ 0.65 - 0.95 sec got 2 MW from 0.7 to 0.83 s. Plasma detached before RF and never really attaches. CVI brightness = 16 (x10^14 ph/s/cm^2/st)
May 12 1995 05:37:53:270PM	950512030	John Goetz	Shot 950512030: plasma - disrupted at 1.63 - many data system problems we had lowered the methane plenum press. in an attempt to find detachment threshold at nl04=1.8x10^20.

Physics Operator Comments
May 12 1995 08:31:02:440AM		Joseph Snipes	MP 113 RF detachment run with impurity puffing Engineer in Charge: Vince Bertolino Physics Operator: Joseph Snipes Session Leader: John Goetz The plan is to try to induce detachment by puffing Ne or CH4 into an RF heated plasma. Standard conditions, 5.3 T, 0.8 MA, nel set to 1.2 x 10^20 m^-2. Copied shot 950509013 except for higher density. Prefill set to 2.0 x 10^-5 Torr.
May 12 1995 08:42:36:680AM	950512001	Joseph Snipes	Shot 1 Fizzle!
May 12 1995 08:59:56:630AM	950512002	Joseph Snipes	Shot 2 Prefill set to 1.7 x 10^-5 Torr. Good shot.
May 12 1995 09:16:23:950AM	950512003	Joseph Snipes	Shot 3 Copied wire 9 FSP controller into wire 9 from shot 950405022 segment 2. Then, copied RXL and ZXL gains and waveforms from the same shot and turned off STRKPSI controller. Good shot.
May 12 1995 09:33:22:390AM	950512004	Joseph Snipes	Shot 4 Increased gain on FSP controller from 0.506 sec to 8. Good shot. ICRF H-modes from 0.64 - 0.7, 0.75 - 0.8, 0.92 - 0.99 sec.
May 12 1995 09:59:37:740AM	950512005	Joseph Snipes	Shot 5 Put RXU to zero during the flattop to try to save power on EF2 at Horne's suggestion. Enabled pulse gas 1, neon, with a 20 ms, 100 V pulse starting at 0.9 sec. Good shot. ICRF H-modes from 0.6 to 1 sec. ELMy from 0.8 - 1.0 sec.
May 12 1995 10:24:06:550AM	950512006	Joseph Snipes	Shot 6 Made RXU -1.5 cm opposite to previous shot, again at Horne's suggestion. Neon puff at 0.85 sec for 40 ms. Good shot. ICRF H-modes from 0.65 - 0.76 and 0.83 - 0.89 sec.
May 12 1995 10:31:18:700AM	950512007	Joseph Snipes	Shot 7 Repeat. Good shot. RF H-modes from 0.64 - 0.7 and 0.78 - 0.91 sec.
May 12 1995 10:58:46:630AM	950512008	Joseph Snipes	Shot 8 Added step in FSP controller signal up by 5 mm from 0.5 to 0.75 sec. Neon puff starting at 0.825 sec for 60 msec. Good shot. H-mode 0.63 - 0.9, ELM-free until 0.7, then ELMy.
May 12 1995 11:19:02:370AM	950512009	Joseph Snipes	Shot 9 Neon puffs at 0.7, 0.8, and 0.9 s each for 20 ms. Good shot. Short ELM-free H-modes 0.63 - 0.7, then ELMy from 0.7 - 1.0 with a short L phase around 0.85 s.
May 12 1995 11:24:13:440AM	950512010	Joseph Snipes	Shot 10 Density raised to nel = 1.5 x 10^20 m^-2. No TF.
May 12 1995 11:38:46:500AM	950512011	Joseph Snipes	Shot 11 Density raised to nel = 1.5 x 10^20 m^-2. Disrupted at 0.46 sec. Large Moly injection.
May 12 1995 11:57:18:820AM	950512012	Joseph Snipes	Shot 12 Try again. Good shot. ELM-free and ELMy H-modes in and out throughout the RF pulse from 0.63 to 1.05 sec.
May 12 1995 12:23:45:150PM	950512013	Joseph Snipes	Shot 13 RCUR moved in by 2 mm from 0.6 sec to 1.0 sec to increase the outer gap. Good shot. In and out of ELMy and ELM-free H-mode form 0.63 to 1.05 sec.
May 12 1995 12:24:54:430PM	950512014	Joseph Snipes	Shot 14 Good shot. RF down to 1 MW. No H-mode, but some dithering.
May 12 1995 12:44:30:520PM	950512015	Joseph Snipes	Shot 15 Took out step in FSP controller. Increased density ramp rate between 0.5 and 0.6 sec. Turned on neon puffs at 0.7, 0.8, and 0.9 for 20 msec each. Disrupted at 1.13 sec. Apparently too much neon.
May 12 1995 01:01:03:750PM	950512016	Joseph Snipes	Shot 16 Turned off neon puff at 0.9 s and made puffs at 0.7 and 0.8 40 msec each. Disrupted at 0.9 sec. Still too much neon.
May 12 1995 01:29:50:900PM	950512017	Joseph Snipes	Shot 17 Turned off neon. Good shot. Disrupted in rampdown at 1.29 sec. Not enough RF power to sustain the sharkfin (only 1 MW).
May 12 1995 01:27:50:210PM	950512018	Joseph Snipes	Shot 18 Methane puff from 0.7 to 0.9 sec at 100 V and 3 psi. Good shot.
May 12 1995 01:41:38:580PM	950512019	Joseph Snipes	Shot 19 Raised pressure of methane to 5 psi. Good shot.
May 12 1995 01:52:35:120PM	950512020	Joseph Snipes	Shot 20 Methane puff shifted to start at 0.8 sec and end at 1 sec. Good shot.
May 12 1995 02:17:19:930PM	950512021	Joseph Snipes	Shot 21 Raised pressure on A side deuterium plenum to 22 psi. Moved methane puff to start at 0.65 sec and end at 0.85 sec. FSP set to -1.75 cm during flattop. Disrupted at 0.64 sec. EF2 railed. It seems that the elongation increased too much because of the drop in the FSP controller.
May 12 1995 02:20:34:480PM	950512022	Joseph Snipes	Shot 22 FSP set to -1.25 cm during the flattop. Good shot.
May 12 1995 02:47:40:900PM	950512023	Joseph Snipes	Shot 23 Increase RF power. Good shot. ELMy RF H-mode from 0.72 - 0.82 sec.
May 12 1995 03:05:13:010PM	950512024	Joseph Snipes	Shot 24 Increase methane plenum pressure to 7 psi. Good shot. No H-mode. Dithering from 0.73 - 1.03 sec.
May 12 1995 03:34:27:290PM	950512025	Joseph Snipes	Shot 25 Increase methane plenum pressure to 9 psi and puff from 0.65 - 0.95 s. Good shot. No H-mode. Dithering from 0.73 - 0.87 sec.
May 12 1995 03:47:34:880PM	950512026	Joseph Snipes	Shot 26 Repeat. Good shot.
May 12 1995 04:27:04:150PM	950512028	Joseph Snipes	Shot 28 Enabled the NINJA gas system with 21 psi of deuterium. NINJA puff from 0.5 for 80 ms, expecting a 70 ms delay before the gas gets into the plasma. Raising the density to 1.8 x 10^20 m^-3. Good shot. NINJA did not inject.
May 12 1995 04:44:24:630PM	950512029	Joseph Snipes	Shot 29 Try NINJA puff again for 80 ms from 0.5 s and methane puff 0.65 - 0.85 s. Good shot. Disrupted at 1.0 sec.
May 12 1995 05:09:44:410PM	950512030	Joseph Snipes	Shot 30 Reduced methane pressure to 5 psi. Disrupted at 0.63 sec. Computer errors.

Engineering Operator Comments
Shot	Time	Type	Status	Comment
1	05:54:49:710AM	Plasma	Ok
2	08:41:33:570AM	Plasma	Ok
3	09:01:03:930AM	Plasma	Ok
4	09:18:54:550AM	Plasma	Ok	No Faults.
5	09:43:11:830AM	Plasma	Ok	comm fault oh2l after fizzle detector
6	10:02:25:310AM	Plasma	Ok
7	10:23:18:100AM	Plasma	Ok
8	10:41:46:010AM	Plasma	Ok
9	11:00:35:680AM	Plasma	Ok
10	11:18:24:760AM	Plasma	Bad	no tf
11	11:29:46:010AM	Plasma	Ok
12	11:41:46:700AM	Plasma	Ok	comm faults after the fizzle detector
13	11:57:57:680AM	Plasma	Ok	comm fault after disruption
14	12:11:41:750PM	Plasma	Ok
15	12:26:43:800PM	Plasma	Ok
16	12:46:07:110PM	Plasma	Ok
17	12:59:48:810PM	Plasma	Ok	No Faults.
18	01:16:04:500PM	Plasma	Ok	No Faults.
19	01:31:36:020PM	Plasma	Ok	No Faults.
20	01:48:21:570PM	Plasma	Ok	No Faults.
21	02:01:40:920PM	Plasma	Ok	No Faults.
22	02:16:51:990PM	Plasma	Ok	comm fault OH1, OH2L, & EF1U
23	02:35:46:650PM	Plasma	Ok	No Faults.
24	02:56:17:890PM	Plasma	Ok	No Faults.
25	03:22:43:470PM	Plasma	Ok	No Faults.
26	03:33:35:100PM	Plasma	Ok	Comm fault OH1, OH2L,&ef1U
27	03:51:58:950PM	Plasma	Ok	No Faults.
28	04:22:03:620PM	Plasma	Ok	Comm Fault OH2L,OH1, EF1U
29	04:35:52:070PM	Plasma	Ok	NO Faults.
30	05:04:13:240PM	Plasma	Ok	No Faults.
31	05:38:40:480PM	Test	Ok
32	05:53:16:780PM	Test	Ok
33	06:03:48:100PM	Test	Ok	punt