Alcator C-Mod Run 1040108 Information

Miniproposals

Miniproposal: 376

Date Filed: 11/25/2003

Title: Study of the Efficiency of ICRF Minority Heating and Investigation of the Cause of Low H-mode Plasma

First Author: Yijun Lin

Session Leader: Yijun Lin (shots 1-25)

Operators
Session leader(s):	Yijun Lin
Physics operator(s):	Earl Marmar
Engineering operator(s):	Unknown

Engineering Operator Run Comment
MP# 376 Performance/Efficiency

Session Leader Plans

Physics Operators Plans

Session Leader Summaries

Entered: Jul 7 2004 03:49:02:040PM

Author: Yijun Lin

MP376. plasma performance evaluation.
SL: Yijun Lin
PO: E. Marmar

Summary:

Compared shot 1 with shot 1040107031 after ECDC in D overnight.
They are very similar.

Outer gap scan: shot 1-5. The dependence is insignicant, the same
result as in 1031209.

Density scan: 5, 6, 7. insensitive. (neutral pressure was higher
in these several shots than the earlier shots).

Pellet: 8, 9, 10, 11, 12. (9 and 12 no pellet, but low density
nl04 ~ 0.6e20)
The stored energy is similar with/without the pellet.
The performance is much better at this low density, and the
H-mode is more ELM-free like.

100% radiated power shots: 13-24
with/without rf, check the efficiency of rf heating.

Comparison of 18 and 15 shows the rf efficiency is
be about 85%. (Argon puff)
Comparison of 21 and 22 and 23 shows the rf efficiency
must exceed 70%. (Neon puff)
Due to computer problems near the end of the run, no good
shot with rf and neon was obtained.

Best performance was obtained in shots 9 and 12 (Low density
shots), in which Wmhd > 160 kJ at 3.5 MW power, with delta(W)/Prf
at >35 kJ/MW.

Probably, the performance was degraded later in the day after
a series programed disruptions; unfortunately, we did not
have time to explore this.

Physics Operator Summaries

Entered: Jul 7 2004 04:36:48:380PM

Author: Earl Marmar

physop run summary 1040108

mp 376 performance evaluation

Session Leader Yijun Lin
physop: Marmar

2'nd day after boronization
Overnight ECDC in D_2, P_guage = 2e-4 torr
Temp was at 35 degrees C (PLC trip, intended 60 degrees)

Engineering setup

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

Power systems the same as on 1040107004

A-coils should be hooked up as on 1040107004 (+Dtop -Dbot -Jtop +Jbot), and the power supply should be enabled.

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)
fill Ninja plenum with 150 Torr NEON

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

________________________

The run got a significant way through the plan.

The performance evaluation was at 1 MA, starting with nl_04 target
1.0e20.

A gap scan was completed, showing no strong dependence of confinement
on gap. The early shots had good performance, with H-factors above
1.5, and steady EDA plasmas. D port was not available today; rf power
was around 3.5 MW.

We tried several PEP shots, with decent (transient) performance, not
too different from some of the better PEP shots from 1995 (950609013
and 950120016, for example).

100% radiated power was tried with both argon (shots 13-18) and neon
(shots 21-24). It looks like we may have gotten close with the argon
to the desired conditions, both ohmic and with rf. For neon, we didn't
get it quite right (either too little or too much), and ran out of
shots.

Getting just the right amount of impurity is tricky, both with ninja
(neon) and one of the regular gas valves (argon). Too much, and the
plasma disrupts quickly, without a phase of moderately increasing
radiation over several confinement times. Too little, and 100%
radiation is not reached.

There were a few engineering problems today. The first 3 hours of the
run were hampered by camac errors (loss of bus signals) and there were
only 5 shots by noontime, as the problem was chased between shots. The
last shot was a no-power cycle due to a computer hang in init.

The machine ran well, with 2 fizzles out of 25 plasma attempts.

Session Leader Comments

Jan 8 2004 08:40:18:187AM Yijun Lin 1040108: MP 376 (2nd try)

0: Check whether ECDC in D overnight enhances performance.
1. Run outer gap scan again.
2. PEP mode confinement. Compare confinement.
3. 100% radiated plasma.
4. impurity screening
5. high performance ELM free H-modes, check coupling resistance.

Jan 8 2004 11:33:40:533AM 1040108001 Yijun Lin shot 1: (load shot 1040107031, check whether ECDC in D overnight helps).
1 MA, 5.4 T, nl04 = 1e20 m^-2
right gap 0.95cm
RF request: E 1.15 MW, J 1.95 MW, 0.6-1.3 sec
Result: plasma.

Wmhd_max= 152 kJ @ Prf = 3.6 MW
dW = Wmhd_max - Wmhd_oh = 112 kJ.
dW/Prf = 31 kJ/MW.
Neutral pressure: ~0.15
(H-mode is getting better with time!)

(Very similar to shot 1040107031).

Next: try outer gap 1.5 cm

Jan 8 2004 09:28:51:143AM 1040108002 Yijun Lin shot 2:
1 MA, 5.4 T, nl04 = 1e20 m^-2
right gap 1.5 cm
RF request: E 1.15 MW, J 1.95 MW, 0.6-1.3 sec
Result: plasma.

Wmhd_max= 153 kJ @ Prf = 3.6 MW
dW = Wmhd_max - Wmhd_oh = 100 kJ. (ohmic Wmhd is higher)
dW/Prf = 28 kJ/MW.
Neutral pressure: ~0.2
EFIT was run with fewer data.

Jan 8 2004 11:08:13:400AM 1040108003 Yijun Lin shot 3: Delayed because of engineering CAMAC problems.
1 MA, 5.4 T, nl04 = 1e20 m^-2
right gap 2 cm
RF request: E 1.15 MW, J 1.95 MW, 0.6-1.3 sec
Result: plasma.

Wmhd_max= 147 kJ @ Prf = 3.4 MW
dW = Wmhd_max - Wmhd_oh = 92 kJ.
dW/Prf = 27 kJ/MW.
(H-mode is getting better with time! similar to shot 1.)
EFIT was run with fewer data.

Jan 8 2004 11:40:02:583AM 1040108004 Yijun Lin shot 4: Delayed because of engineering CAMAC problems.
1 MA, 5.4 T, nl04 = 1e20 m^-2
right gap .5 cm
RF request: E 1.15 MW, J 1.95 MW, 0.6-1.3 sec
Result: plasma.

Wmhd_max= 130 kJ @ Prf = 3.4 MW
dW = Wmhd_max - Wmhd_oh = 86 kJ.
dW/Prf = 25 kJ/MW.
Note: neutral pressure has increased significantly since shot 03.
Next: back to gap as shot 1. See if it is repeatable.

Jan 8 2004 12:16:44:490PM 1040108005 Yijun Lin shot 5: Delayed because of engineering CAMAC problems.
1 MA, 5.4 T, nl04 = 1e20 m^-2
right gap 1. cm
RF request: E 1.15 MW, J 1.95 MW, 0.6-1.3 sec
Result: plasma.

Wmhd_max= 138 kJ @ Prf = 3.5 MW
dW = Wmhd_max - Wmhd_oh = 95 kJ.
dW/Prf = 27.1 kJ/MW.
Note: neutral pressure has increased significantly since shot 03.

Next: nl04 = 0.8e20m^-2, see whether we get better performance.

Jan 8 2004 12:30:46:450PM 1040108006 Yijun Lin shot 6:
1 MA, 5.4 T, nl04 = .85e20 m^-2
right gap 1. cm
RF request: E 1.15 MW, J 1.95 MW, 0.6-1.3 sec
Result: plasma.

Wmhd_max= 142 kJ @ Prf = 3.5 MW
dW = Wmhd_max - Wmhd_oh = 100 kJ.
dW/Prf = 28.6 kJ/MW.

Next: Lower density again.

Jan 8 2004 12:44:37:237PM 1040108007 Yijun Lin shot 7:
1 MA, 5.4 T, nl04 = .75e20 m^-2
right gap 1. cm
RF request: E 1.15 MW, J 1.95 MW, 0.6-1.3 sec
Result: plasma.

Wmhd_max= 142 kJ @ Prf = 3.5 MW
dW = Wmhd_max - Wmhd_oh = 100 kJ.
dW/Prf = 28.6 kJ/MW.

Same as shot 6.

Next: try PEP mode, to check whether the rf can heat ultra-density, and
also whether the confinement is better or worse.

Jan 8 2004 01:05:49:743PM 1040108008 Yijun Lin shot 8:
1 MA, 5.4 T, nl04 = .6e20 m^-2
right gap 1. cm
RF request: E 1.15 MW, J 1.95 MW, 0.7-1.3 sec
Pellet at 0.65 sec.
Result: plasma. FMIT 3 FPA screen current overload at 0.8 sec.
(mistakenly programmed J the same power as E)

Wmhd_max= 147 kJ @ Prf = 3.6 MW
dW = Wmhd_max - Wmhd_oh = 101 kJ.
dW/Prf = 28 kJ/MW.

Next: try one more. Lower J power. Raise E power. Shorten rf pulse.

Jan 8 2004 01:25:56:250PM 1040108010 Yijun Lin shot 10:
1 MA, 5.4 T, nl04 = .65e20 m^-2
RF request: E 1.15 MW, J 1.95 MW, 0.7-1. sec
Pellet at 0.65 sec.
Result: plasma. pellet was at 0.63 sec. too early.

Wmhd_max= 129 kJ @ Prf = 3.4 MW
Several short H-modes.

Next: Try again to get the pellet time right.

Jan 8 2004 01:53:06:417PM 1040108012 Yijun Lin shot 12:
1 MA, 5.4 T, nl04 = .65e20 m^-2
RF request: E 1.15 MW, J 1.95 MW, 0.7-1. sec
Pellet at 0.65 sec.
Result: plasma. No pellet.

Wmhd_max= 162 kJ @ Prf = 3.4 MW
dW = Wmhd_max - Wmhd_oh = 120 kJ.
dW/Prf = 35 kJ/MW
Neutral pressure is 0.03 at Max Wmhd.

Almost identical as shot 11 where a pellet was fired at 0.65 sec.

Next: do impurity screening and 100% radiated power discharges.

Jan 8 2004 02:23:23:663PM 1040108013 Yijun Lin shot 13:
.8 MA, 5.4 T, nl04 = 1.e20 m^-2
RF request: off. Ohmic shot. Argon puff.
Result: plasma. disrupted at 1.2 sec.

Argon was puffed too hard too late.

Jan 8 2004 02:32:56:150PM 1040108014 Yijun Lin hot 14:
.8 MA, 5.4 T, nl04 = 1.e20 m^-2
RF request: off. Ohmic shot. Argon puff.
Result: plasma.

Argon was not enough to let the plasma 'die'.

Jan 8 2004 02:49:11:813PM 1040108015 Yijun Lin shot 15:
.8 MA, 5.4 T, nl04 = 1.e20 m^-2
RF request: off. Ohmic shot. Argon puff.
Result: plasma. disrupted 0.95 sec.

Could be a good shot to calibrate 2pi.
Next: with rf to see how much 2pi signal is needed to
get 100% radiatied power.

Jan 8 2004 03:17:29:573PM 1040108017 Yijun Lin shot 17:
.8 MA, 5.4 T, nl04 = 1.e20 m^-2
RF request: E 1.15 MW, J 1.95 MW, 0.7-1.3 sec
Argon puff.
Result: plasma. disrupted 1.35 sec.

Next: more argon. Longer rf.

Jan 8 2004 03:40:33:240PM 1040108019 Yijun Lin fizzle

Jan 8 2004 03:59:12:153PM 1040108020 Yijun Lin shot 20:
.8 MA, 5.4 T, nl04 = 1.e20 m^-2
RF request: E 1.15 MW, J 1.95 MW, 0.6-1.5 sec
No argon puff.
Result: plasma.
The performance is very bad. H factor barely above 1.

Next: neon puff into ohmic plasma.

Jan 8 2004 04:08:39:327PM 1040108021 Yijun Lin shot 21:
.8 MA, 5.4 T, nl04 = 1.e20 m^-2
RF request: off
Neon puff.
Result: plasma.

Disrupted at a similar Prad level as shot 15.
Next: with RF and compare with shot 18

Jan 8 2004 04:23:11:850PM 1040108022 Yijun Lin shot 22:
.8 MA, 5.4 T, nl04 = 1.e20 m^-2
RF request: E 1.15 MW, J 1.95 MW, 0.7-1.3 sec
Neon puff.
Result: plasma.

Disrupted right after rf pulse.
If assume Prad is close to 100% near the end of rf anyway,
we got 71% effiency compared with shot 21.

Next more neon.

Jan 8 2004 04:32:54:353PM 1040108023 Yijun Lin shot 23:
.8 MA, 5.4 T, nl04 = 1.e20 m^-2
RF request: E 1.15 MW, J 1.95 MW, 0.7-1.3 sec
Neon puff.
Result: plasma.
Almost the same as shot 22. disrupted the same time and the same Prad
before the disruption.

Next: more neon.

Jan 8 2004 04:43:45:390PM 1040108024 Yijun Lin shot 24:
.8 MA, 5.4 T, nl04 = 1.e20 m^-2
RF request: E 1.15 MW, J 1.95 MW, 0.7-1.3 sec
Neon puff.
Result: plasma.
Disrupted too early, 50 ms into rf pulse.

Next: move Neon puff later.

Jan 8 2004 04:47:14:093PM 1040108024 Yijun Lin shot 24:
.8 MA, 5.4 T, nl04 = 1.e20 m^-2
RF request: E 1.15 MW, J 1.95 MW, 0.7-1.3 sec
Neon puff.
Result: plasma.
Disrupted too early, 50 ms into rf pulse.

Next: move Neon puff later.

Jan 8 2004 05:12:51:790PM 1040108026 Yijun Lin no power shot.

Physics Operator Comments

Jan 8 2004 08:48:22:503AM Earl Marmar mp 376 performance evaluation

Session Leader Yijun Lin

2'nd day after boronization
Overnight ECDC in D_2, P_guage = 2e-4 torr
Temp was at 35 degrees C

Engineering setup

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

Power systems the same as on 1040107004

A-coils should be hooked up as on 1040107004 (+Dtop -Dbot -Jtop +Jbot), and the power supply should be enabled.

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)
fill Ninja plenum with 150 Torr NEON

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

Jan 8 2004 09:12:54:467AM 1040108001 Earl Marmar start from 1040107031 LSN 1MA

load segment 1 from 1040107006

plasma

good shot; 3.5 MW, 150 kJ (increasing with time during RF pulse, even though radiated power increasing slowly)
outer gap 1.0 cm

Jan 8 2004 09:30:50:863AM 1040108002 Earl Marmar increase outer gap by 5 mm (decrease rcur 2.5 mm)

plasma

good shot; Wmax 150 kJ and very flat, 3.5 MW
outer gap 14 to 15 mm

lost a lot of bus data - CAMAC problem(s)

Jan 8 2004 11:01:50:773AM 1040108003 Earl Marmar long delay before shot 3: camac problem(s)

increase outer gap another 5 mm (decrease RCUR another 2.5 mm)

plasma

good shot; still have missing bus data (camac problems).

outer gap 18 to 20 mm

Prf 3.3 MW (1 early trip) ; Wmax 145 kJ (rising through RF pulse)

Jan 8 2004 11:42:36:820AM 1040108004 Earl Marmar delay before shot 4 to check more camac hardware

reduce outer gap to 5 mm (increase rcur to 0.6635)

plasma; good shot
outer gap 4 - 6 mm

Prf 3.4 MW, Wmax 133 kJ

still have camac errors, missing bus data

Jan 8 2004 12:19:31:973PM 1040108005 Earl Marmar back to outer gap from shot 1 (10 mm), rcur to 0.6610

delay for camac debugging

plasma; good shot

Prf = 3.5 MW, Wmax = 143 kJ
right gap 8 to 10 mm

Jan 8 2004 12:31:31:840PM 1040108006 Earl Marmar reduce target density, nl_04 program to 0.8e20

plasma;

Jan 8 2004 12:45:47:047PM 1040108007 Earl Marmar lower nl_04 target to 0.7e20
plasma

Jan 8 2004 01:16:58:810PM 1040108008 Earl Marmar now switch to PEP mode

pellet at 0.65, RF on at 0.7
nl_04 program to 0.5e19

plasma
PEP mode, Wmax =150 kJ, Prf =3.5 MW

Jan 8 2004 01:18:15:170PM 1040108009 Earl Marmar repeat with shorter RF pulse

plasma
no pellet
nl_04 target = 5 e19
Wmax = 166 kJ, Prf = 3.4 MW

Jan 8 2004 01:32:52:737PM 1040108010 Earl Marmar repeat
plasma
got the pellet, PEP mode
Wmax = 129 kJ

Jan 8 2004 01:52:48:277PM 1040108011 Earl Marmar move pellet 20 msec later (now ~50 ms before RF)

plasma, pep mode

Jan 8 2004 01:53:09:120PM 1040108012 Earl Marmar repeat attempt
plasma
no pellet

Jan 8 2004 02:19:12:160PM 1040108013 Earl Marmar mpve to 100% radiated power part of the run
start with ohmic, argon
increase pressure in Argon plenum to 10 psi (from 1)
program rising puff from .3 to 1.3 s
nl_04 to 1e20, Ip to 0.8 MA

plasma
argon disrupts plasma, but doesn't get in until near the end

Jan 8 2004 03:36:06:457PM 1040108014 Earl Marmar 1 psi on argon plenum
program series of increasing length pulses of Ar at 100 on valve
plasma

Jan 8 2004 03:44:35:647PM 1040108015 Earl Marmar more argon
plasma

Jan 8 2004 03:44:57:540PM 1040108016 Earl Marmar turn rf back on
plasma

RF tripping

Jan 8 2004 03:40:36:600PM 1040108017 Earl Marmar increase argon puffs
plasma

Jan 8 2004 03:40:13:723PM 1040108018 Earl Marmar double argon plenum pressure to 2 psi

plasma; disrupts earlier

Jan 8 2004 03:39:16:520PM 1040108019 Earl Marmar argon off

fizzle; fill pressure about 20% higher than on previous shots

Jan 8 2004 04:02:31:187PM 1040108020 Earl Marmar reduce prepuff by 2 msec to 17 msec
plasma
no argon (but John reports levels are still high during rf)

Jan 8 2004 04:14:54:707PM 1040108021 Earl Marmar puff neon through ninja, no rf
open at .45 for .4 seconds
plasma
disrupt at 0.995

Jan 8 2004 04:23:02:490PM 1040108022 Earl Marmar same ninja neon puff
add rf

plasma
disrupt at 1.55 s

Jan 8 2004 04:24:29:130PM 1040108023 Earl Marmar increase neon (ninja on at 0.3 for .6)

Jan 8 2004 04:46:03:437PM 1040108024 Earl Marmar increase ninja neon plenum pressure from 165 torr to 267 torr

plasma
disrupt early in rf pulse (.654 s)

Jan 8 2004 04:53:16:347PM 1040108025 Earl Marmar delay ninja: trigger at 0.5, 0.4 second duration
fizzle; nothing obviously wrong

Jan 8 2004 06:10:37:440PM 1040108026 Earl Marmar no pcs changes
ninja delayed (from shot 24): trigger at 0.5, duration 0.4
computer hang during init; no power shot

Engineering Operator Comments

Shot Time Type Status Comment

1 08:57:43:523AM Plasma Ok

2 09:11:28:403AM Plasma Ok

3 10:46:23:127AM Plasma Ok

4 11:29:17:423AM Plasma Ok

5 12:10:55:940PM Plasma Ok

6 12:23:36:650PM Plasma Ok

7 12:36:23:887PM Plasma Ok

8 12:50:17:300PM Plasma Ok

9 01:04:22:820PM Plasma Ok

10 01:17:05:683PM Plasma Ok

11 01:30:59:253PM Plasma Ok

12 01:43:29:040PM Plasma Ok

13 02:01:16:420PM Plasma Ok

14 02:18:52:910PM Plasma Ok

15 02:33:53:370PM Plasma Ok

16 02:49:01:750PM Plasma Ok

17 03:06:15:350PM Plasma Ok

18 03:20:04:293PM Plasma Ok

19 03:32:35:783PM Plasma Ok

20 03:46:30:650PM Plasma Ok

21 03:59:32:230PM Plasma Ok

22 04:12:29:737PM Plasma Ok

23 04:24:55:380PM Plasma Ok

24 04:37:25:823PM Plasma Ok

25 04:49:56:860PM Plasma Ok

Session Leader Comments
Jan 8 2004 08:40:18:187AM		Yijun Lin	1040108: MP 376 (2nd try) 0: Check whether ECDC in D overnight enhances performance. 1. Run outer gap scan again. 2. PEP mode confinement. Compare confinement. 3. 100% radiated plasma. 4. impurity screening 5. high performance ELM free H-modes, check coupling resistance.
Jan 8 2004 11:33:40:533AM	1040108001	Yijun Lin	shot 1: (load shot 1040107031, check whether ECDC in D overnight helps). 1 MA, 5.4 T, nl04 = 1e20 m^-2 right gap 0.95cm RF request: E 1.15 MW, J 1.95 MW, 0.6-1.3 sec Result: plasma. Wmhd_max= 152 kJ @ Prf = 3.6 MW dW = Wmhd_max - Wmhd_oh = 112 kJ. dW/Prf = 31 kJ/MW. Neutral pressure: ~0.15 (H-mode is getting better with time!) (Very similar to shot 1040107031). Next: try outer gap 1.5 cm
Jan 8 2004 09:28:51:143AM	1040108002	Yijun Lin	shot 2: 1 MA, 5.4 T, nl04 = 1e20 m^-2 right gap 1.5 cm RF request: E 1.15 MW, J 1.95 MW, 0.6-1.3 sec Result: plasma. Wmhd_max= 153 kJ @ Prf = 3.6 MW dW = Wmhd_max - Wmhd_oh = 100 kJ. (ohmic Wmhd is higher) dW/Prf = 28 kJ/MW. Neutral pressure: ~0.2 EFIT was run with fewer data.
Jan 8 2004 11:08:13:400AM	1040108003	Yijun Lin	shot 3: Delayed because of engineering CAMAC problems. 1 MA, 5.4 T, nl04 = 1e20 m^-2 right gap 2 cm RF request: E 1.15 MW, J 1.95 MW, 0.6-1.3 sec Result: plasma. Wmhd_max= 147 kJ @ Prf = 3.4 MW dW = Wmhd_max - Wmhd_oh = 92 kJ. dW/Prf = 27 kJ/MW. (H-mode is getting better with time! similar to shot 1.) EFIT was run with fewer data.
Jan 8 2004 11:40:02:583AM	1040108004	Yijun Lin	shot 4: Delayed because of engineering CAMAC problems. 1 MA, 5.4 T, nl04 = 1e20 m^-2 right gap .5 cm RF request: E 1.15 MW, J 1.95 MW, 0.6-1.3 sec Result: plasma. Wmhd_max= 130 kJ @ Prf = 3.4 MW dW = Wmhd_max - Wmhd_oh = 86 kJ. dW/Prf = 25 kJ/MW. Note: neutral pressure has increased significantly since shot 03. Next: back to gap as shot 1. See if it is repeatable.
Jan 8 2004 12:16:44:490PM	1040108005	Yijun Lin	shot 5: Delayed because of engineering CAMAC problems. 1 MA, 5.4 T, nl04 = 1e20 m^-2 right gap 1. cm RF request: E 1.15 MW, J 1.95 MW, 0.6-1.3 sec Result: plasma. Wmhd_max= 138 kJ @ Prf = 3.5 MW dW = Wmhd_max - Wmhd_oh = 95 kJ. dW/Prf = 27.1 kJ/MW. Note: neutral pressure has increased significantly since shot 03. Next: nl04 = 0.8e20m^-2, see whether we get better performance.
Jan 8 2004 12:30:46:450PM	1040108006	Yijun Lin	shot 6: 1 MA, 5.4 T, nl04 = .85e20 m^-2 right gap 1. cm RF request: E 1.15 MW, J 1.95 MW, 0.6-1.3 sec Result: plasma. Wmhd_max= 142 kJ @ Prf = 3.5 MW dW = Wmhd_max - Wmhd_oh = 100 kJ. dW/Prf = 28.6 kJ/MW. Next: Lower density again.
Jan 8 2004 12:44:37:237PM	1040108007	Yijun Lin	shot 7: 1 MA, 5.4 T, nl04 = .75e20 m^-2 right gap 1. cm RF request: E 1.15 MW, J 1.95 MW, 0.6-1.3 sec Result: plasma. Wmhd_max= 142 kJ @ Prf = 3.5 MW dW = Wmhd_max - Wmhd_oh = 100 kJ. dW/Prf = 28.6 kJ/MW. Same as shot 6. Next: try PEP mode, to check whether the rf can heat ultra-density, and also whether the confinement is better or worse.
Jan 8 2004 01:05:49:743PM	1040108008	Yijun Lin	shot 8: 1 MA, 5.4 T, nl04 = .6e20 m^-2 right gap 1. cm RF request: E 1.15 MW, J 1.95 MW, 0.7-1.3 sec Pellet at 0.65 sec. Result: plasma. FMIT 3 FPA screen current overload at 0.8 sec. (mistakenly programmed J the same power as E) Wmhd_max= 147 kJ @ Prf = 3.6 MW dW = Wmhd_max - Wmhd_oh = 101 kJ. dW/Prf = 28 kJ/MW. Next: try one more. Lower J power. Raise E power. Shorten rf pulse.
Jan 8 2004 01:25:56:250PM	1040108010	Yijun Lin	shot 10: 1 MA, 5.4 T, nl04 = .65e20 m^-2 RF request: E 1.15 MW, J 1.95 MW, 0.7-1. sec Pellet at 0.65 sec. Result: plasma. pellet was at 0.63 sec. too early. Wmhd_max= 129 kJ @ Prf = 3.4 MW Several short H-modes. Next: Try again to get the pellet time right.
Jan 8 2004 01:53:06:417PM	1040108012	Yijun Lin	shot 12: 1 MA, 5.4 T, nl04 = .65e20 m^-2 RF request: E 1.15 MW, J 1.95 MW, 0.7-1. sec Pellet at 0.65 sec. Result: plasma. No pellet. Wmhd_max= 162 kJ @ Prf = 3.4 MW dW = Wmhd_max - Wmhd_oh = 120 kJ. dW/Prf = 35 kJ/MW Neutral pressure is 0.03 at Max Wmhd. Almost identical as shot 11 where a pellet was fired at 0.65 sec. Next: do impurity screening and 100% radiated power discharges.
Jan 8 2004 02:23:23:663PM	1040108013	Yijun Lin	shot 13: .8 MA, 5.4 T, nl04 = 1.e20 m^-2 RF request: off. Ohmic shot. Argon puff. Result: plasma. disrupted at 1.2 sec. Argon was puffed too hard too late.
Jan 8 2004 02:32:56:150PM	1040108014	Yijun Lin	hot 14: .8 MA, 5.4 T, nl04 = 1.e20 m^-2 RF request: off. Ohmic shot. Argon puff. Result: plasma. Argon was not enough to let the plasma 'die'.
Jan 8 2004 02:49:11:813PM	1040108015	Yijun Lin	shot 15: .8 MA, 5.4 T, nl04 = 1.e20 m^-2 RF request: off. Ohmic shot. Argon puff. Result: plasma. disrupted 0.95 sec. Could be a good shot to calibrate 2pi. Next: with rf to see how much 2pi signal is needed to get 100% radiatied power.
Jan 8 2004 03:17:29:573PM	1040108017	Yijun Lin	shot 17: .8 MA, 5.4 T, nl04 = 1.e20 m^-2 RF request: E 1.15 MW, J 1.95 MW, 0.7-1.3 sec Argon puff. Result: plasma. disrupted 1.35 sec. Next: more argon. Longer rf.
Jan 8 2004 03:40:33:240PM	1040108019	Yijun Lin	fizzle
Jan 8 2004 03:59:12:153PM	1040108020	Yijun Lin	shot 20: .8 MA, 5.4 T, nl04 = 1.e20 m^-2 RF request: E 1.15 MW, J 1.95 MW, 0.6-1.5 sec No argon puff. Result: plasma. The performance is very bad. H factor barely above 1. Next: neon puff into ohmic plasma.
Jan 8 2004 04:08:39:327PM	1040108021	Yijun Lin	shot 21: .8 MA, 5.4 T, nl04 = 1.e20 m^-2 RF request: off Neon puff. Result: plasma. Disrupted at a similar Prad level as shot 15. Next: with RF and compare with shot 18
Jan 8 2004 04:23:11:850PM	1040108022	Yijun Lin	shot 22: .8 MA, 5.4 T, nl04 = 1.e20 m^-2 RF request: E 1.15 MW, J 1.95 MW, 0.7-1.3 sec Neon puff. Result: plasma. Disrupted right after rf pulse. If assume Prad is close to 100% near the end of rf anyway, we got 71% effiency compared with shot 21. Next more neon.
Jan 8 2004 04:32:54:353PM	1040108023	Yijun Lin	shot 23: .8 MA, 5.4 T, nl04 = 1.e20 m^-2 RF request: E 1.15 MW, J 1.95 MW, 0.7-1.3 sec Neon puff. Result: plasma. Almost the same as shot 22. disrupted the same time and the same Prad before the disruption. Next: more neon.
Jan 8 2004 04:43:45:390PM	1040108024	Yijun Lin	shot 24: .8 MA, 5.4 T, nl04 = 1.e20 m^-2 RF request: E 1.15 MW, J 1.95 MW, 0.7-1.3 sec Neon puff. Result: plasma. Disrupted too early, 50 ms into rf pulse. Next: move Neon puff later.
Jan 8 2004 04:47:14:093PM	1040108024	Yijun Lin	shot 24: .8 MA, 5.4 T, nl04 = 1.e20 m^-2 RF request: E 1.15 MW, J 1.95 MW, 0.7-1.3 sec Neon puff. Result: plasma. Disrupted too early, 50 ms into rf pulse. Next: move Neon puff later.
Jan 8 2004 05:12:51:790PM	1040108026	Yijun Lin	no power shot.

Physics Operator Comments
Jan 8 2004 08:48:22:503AM		Earl Marmar	mp 376 performance evaluation Session Leader Yijun Lin 2'nd day after boronization Overnight ECDC in D_2, P_guage = 2e-4 torr Temp was at 35 degrees C Engineering setup Run begins at 09:00 and ends at 17:00. Power systems the same as on 1040107004 A-coils should be hooked up as on 1040107004 (+Dtop -Dbot -Jtop +Jbot), and the power supply should be enabled. 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) fill Ninja plenum with 150 Torr NEON Enable the following gate valves, assuming no vacuum problems: ECE, VUV, DNB
Jan 8 2004 09:12:54:467AM	1040108001	Earl Marmar	start from 1040107031 LSN 1MA load segment 1 from 1040107006 plasma good shot; 3.5 MW, 150 kJ (increasing with time during RF pulse, even though radiated power increasing slowly) outer gap 1.0 cm
Jan 8 2004 09:30:50:863AM	1040108002	Earl Marmar	increase outer gap by 5 mm (decrease rcur 2.5 mm) plasma good shot; Wmax 150 kJ and very flat, 3.5 MW outer gap 14 to 15 mm lost a lot of bus data - CAMAC problem(s)
Jan 8 2004 11:01:50:773AM	1040108003	Earl Marmar	long delay before shot 3: camac problem(s) increase outer gap another 5 mm (decrease RCUR another 2.5 mm) plasma good shot; still have missing bus data (camac problems). outer gap 18 to 20 mm Prf 3.3 MW (1 early trip) ; Wmax 145 kJ (rising through RF pulse)
Jan 8 2004 11:42:36:820AM	1040108004	Earl Marmar	delay before shot 4 to check more camac hardware reduce outer gap to 5 mm (increase rcur to 0.6635) plasma; good shot outer gap 4 - 6 mm Prf 3.4 MW, Wmax 133 kJ still have camac errors, missing bus data
Jan 8 2004 12:19:31:973PM	1040108005	Earl Marmar	back to outer gap from shot 1 (10 mm), rcur to 0.6610 delay for camac debugging plasma; good shot Prf = 3.5 MW, Wmax = 143 kJ right gap 8 to 10 mm
Jan 8 2004 12:31:31:840PM	1040108006	Earl Marmar	reduce target density, nl_04 program to 0.8e20 plasma;
Jan 8 2004 12:45:47:047PM	1040108007	Earl Marmar	lower nl_04 target to 0.7e20 plasma
Jan 8 2004 01:16:58:810PM	1040108008	Earl Marmar	now switch to PEP mode pellet at 0.65, RF on at 0.7 nl_04 program to 0.5e19 plasma PEP mode, Wmax =150 kJ, Prf =3.5 MW
Jan 8 2004 01:18:15:170PM	1040108009	Earl Marmar	repeat with shorter RF pulse plasma no pellet nl_04 target = 5 e19 Wmax = 166 kJ, Prf = 3.4 MW
Jan 8 2004 01:32:52:737PM	1040108010	Earl Marmar	repeat plasma got the pellet, PEP mode Wmax = 129 kJ
Jan 8 2004 01:52:48:277PM	1040108011	Earl Marmar	move pellet 20 msec later (now ~50 ms before RF) plasma, pep mode
Jan 8 2004 01:53:09:120PM	1040108012	Earl Marmar	repeat attempt plasma no pellet
Jan 8 2004 02:19:12:160PM	1040108013	Earl Marmar	mpve to 100% radiated power part of the run start with ohmic, argon increase pressure in Argon plenum to 10 psi (from 1) program rising puff from .3 to 1.3 s nl_04 to 1e20, Ip to 0.8 MA plasma argon disrupts plasma, but doesn't get in until near the end
Jan 8 2004 03:36:06:457PM	1040108014	Earl Marmar	1 psi on argon plenum program series of increasing length pulses of Ar at 100 on valve plasma
Jan 8 2004 03:44:35:647PM	1040108015	Earl Marmar	more argon plasma
Jan 8 2004 03:44:57:540PM	1040108016	Earl Marmar	turn rf back on plasma RF tripping
Jan 8 2004 03:40:36:600PM	1040108017	Earl Marmar	increase argon puffs plasma
Jan 8 2004 03:40:13:723PM	1040108018	Earl Marmar	double argon plenum pressure to 2 psi plasma; disrupts earlier
Jan 8 2004 03:39:16:520PM	1040108019	Earl Marmar	argon off fizzle; fill pressure about 20% higher than on previous shots
Jan 8 2004 04:02:31:187PM	1040108020	Earl Marmar	reduce prepuff by 2 msec to 17 msec plasma no argon (but John reports levels are still high during rf)
Jan 8 2004 04:14:54:707PM	1040108021	Earl Marmar	puff neon through ninja, no rf open at .45 for .4 seconds plasma disrupt at 0.995
Jan 8 2004 04:23:02:490PM	1040108022	Earl Marmar	same ninja neon puff add rf plasma disrupt at 1.55 s
Jan 8 2004 04:24:29:130PM	1040108023	Earl Marmar	increase neon (ninja on at 0.3 for .6)
Jan 8 2004 04:46:03:437PM	1040108024	Earl Marmar	increase ninja neon plenum pressure from 165 torr to 267 torr plasma disrupt early in rf pulse (.654 s)
Jan 8 2004 04:53:16:347PM	1040108025	Earl Marmar	delay ninja: trigger at 0.5, 0.4 second duration fizzle; nothing obviously wrong
Jan 8 2004 06:10:37:440PM	1040108026	Earl Marmar	no pcs changes ninja delayed (from shot 24): trigger at 0.5, duration 0.4 computer hang during init; no power shot

Engineering Operator Comments
Shot	Time	Type	Status	Comment
1	08:57:43:523AM	Plasma	Ok
2	09:11:28:403AM	Plasma	Ok
3	10:46:23:127AM	Plasma	Ok
4	11:29:17:423AM	Plasma	Ok
5	12:10:55:940PM	Plasma	Ok
6	12:23:36:650PM	Plasma	Ok
7	12:36:23:887PM	Plasma	Ok
8	12:50:17:300PM	Plasma	Ok
9	01:04:22:820PM	Plasma	Ok
10	01:17:05:683PM	Plasma	Ok
11	01:30:59:253PM	Plasma	Ok
12	01:43:29:040PM	Plasma	Ok
13	02:01:16:420PM	Plasma	Ok
14	02:18:52:910PM	Plasma	Ok
15	02:33:53:370PM	Plasma	Ok
16	02:49:01:750PM	Plasma	Ok
17	03:06:15:350PM	Plasma	Ok
18	03:20:04:293PM	Plasma	Ok
19	03:32:35:783PM	Plasma	Ok
20	03:46:30:650PM	Plasma	Ok
21	03:59:32:230PM	Plasma	Ok
22	04:12:29:737PM	Plasma	Ok
23	04:24:55:380PM	Plasma	Ok
24	04:37:25:823PM	Plasma	Ok
25	04:49:56:860PM	Plasma	Ok