Alcator C-Mod Run 930730 Information

Miniproposals

Miniproposal: 010

Date Filed: 7/13/1993

Title: Transport in Ohmic Plasmas

First Author: Martin Greenwald

Session Leader: Martin Greenwald (shots 1-25)

Operators
Session leader(s):	Martin Greenwald
Physics operator(s):	Joseph Snipes
Engineering operator(s):	Unknown

Engineering Operator Run Comment
ohmic transport - Snipes

Session Leader Plans

Physics Operators Plans

Session Leader Summaries

Entered: Jul 7 2004 03:49:08:273PM

Author: To Be Determined

Run Summary for July 7, 1993

The intention was continue the parameter scans begun yesterday in
pursuit of data suitable for confinement studies. In particular, we
attempted to push density at the highest currents available. Only a few
shots will be useful because: 1. Only 1 of the first 12 shots had
substantial plasma current - and it disrupted at .15 sec,; 2. We still
have trouble raising the density, even when operating near .5 MA. 3. On
shot 18 and after 19, the ECE instrument ran into problems and took no
data. Of 25 shots we had 7 duds, 7 fizzles, 11 plasmas. Of the 11
plasmas, 6 were (more or less) disruption free.

->Shots 930730013, 014, 015, and 019 deserve a closer look.

->Note that Record (thermal) Plasma Currents were reached successively on
->shots 18 and 19. Ip = .515 MA on 19.

Line averaged densities on these shots were approximately 1 x 10^20.
The calculated density limit should be on the order 4 x 10^20. It is
far from clear why we have so much trouble in this regard. By shot 24
we had only reached 1.5 x 10^20. Zeff was ~ 1 for much of this shot.

Note that for reasons too embarrassing to Bob Granetz to mention here,
the time base for xray diagnostics for shots 1-14 are partially
corrupted.

Physics Operator Summaries

Session Leader Comments

Jul 30 1993 09:46:45:710AM Joseph Snipes Ohmic Transport Run

Scaling of density at fixed current around 400 to 450 kA starting with
930729025, which was a good shot from yesterday. Argon will be added to get
ion temperatures from HIREX. Otherwise, attempting stable reproducible plasmas.

Jul 30 1993 10:04:32:040AM 930730001 Martin Greenwald Start by trying to repeat 930729025

Fizzle

Jul 30 1993 10:30:22:720AM 930730001 Joseph Snipes Shot 1
Starting with 930729025 except moving Ar puff from 0 to -100 ms. Reduced H gas
around 200 ms to attempt to flatten the density after 200 ms.
Flash, but no current rise

Jul 30 1993 10:30:40:880AM 930730001 Joseph Snipes Shot 2
Starting with 930729025 except moving Ar puff from 0 to -100 ms. Reduced H gas
around 200 ms to attempt to flatten the density after 200 ms.
Flash, but no current rise

Jul 30 1993 10:31:08:270AM 930730002 Joseph Snipes Shot 2
Repeat. Same.

Jul 30 1993 10:37:47:960AM 930730002 Joseph Snipes Shot 3
Moved Ar puff to -50 ms and reduced it a bit after the initial puff. Moved
start of Bay A side gas puff to 18 ms. Reduced prefill to 1.2 x 10**-5 Torr.
Wimper!

Jul 30 1993 10:44:21:880AM 930730002 Martin Greenwald Fizzle

Jul 30 1993 10:41:38:050AM 930730003 Joseph Snipes Shot 3
Moved Ar puff to -50 ms and reduced it a bit after the initial puff. Moved
start of Bay A side gas puff to 18 ms. Reduced prefill to 1.2 x 10**-5 Torr.
Wimper!

Jul 30 1993 10:44:31:650AM 930730003 Martin Greenwald Fizzle

Jul 30 1993 10:55:46:050AM 930730004 Martin Greenwald Good startup, disrupts at .175 sec, .3 MA

Jul 30 1993 11:04:38:110AM 930730005 Joseph Snipes Shot 5
EF2U current program copied into EF2L program to balance those coils. Also
notch removed from the gain on ZCUR wire 2 that was put is several days ago
by Horne for the EFC.
Dud!

Jul 30 1993 11:05:17:030AM 930730005 Martin Greenwald Fizzle

Jul 30 1993 11:23:33:160AM 930730006 Joseph Snipes Shot 6
Increased prefill to 1.2 x 10**-5 Torr.
Dud!

Jul 30 1993 11:30:51:580AM 930730006 Martin Greenwald Dud

Jul 30 1993 11:30:59:670AM 930730007 Martin Greenwald Dud

Jul 30 1993 11:45:25:450AM 930730007 Joseph Snipes Shot 7
Decreased prefill to 9 x 10**-6 Torr. Took out imbalance that had been
programmed in EF2 by reducing EF2L by 40 A to 1710 A at commutation.

Jul 30 1993 11:47:34:780AM 930730008 Martin Greenwald Fizzle

Jul 30 1993 11:49:50:500AM 930730008 Joseph Snipes Shot 8
Increased prefill to 1.3 x 10**-5 Torr.
Fizzle!

Jul 30 1993 11:58:09:150AM 930730008 Joseph Snipes Shot 8
Commutation failure in EF1 supply.

Jul 30 1993 12:12:48:010PM 930730009 Martin Greenwald Dud

Jul 30 1993 12:27:04:010PM 930730009 Joseph Snipes Shot 9
Reduced EF2L by 10 A to 1700 A to balance with EF2U.
Dud!

Jul 30 1993 12:41:00:460PM 930730010 Joseph Snipes Shot 10
Increased prefill to 1.4 x 10**-5 Torr.
Fizzle!

Jul 30 1993 05:05:35:090PM 930730010 Martin Greenwald Fizzle

Jul 30 1993 12:48:56:790PM 930730011 Joseph Snipes Shot 11
Increased gas puff from Bay A side early at -10 ms.
Fizzle.

Jul 30 1993 05:05:43:260PM 930730011 Martin Greenwald Fizzle

Jul 30 1993 12:59:27:510PM 930730012 Joseph Snipes Shot 12
Decreased prefill to 1 x 10**-5 Torr.
fizzle

Jul 30 1993 05:05:56:600PM 930730012 Martin Greenwald Fizzle

Jul 30 1993 01:29:49:540PM 930730013 Martin Greenwald Good Shot
Ip = .46
nel = .5^20
Very Interesting MHD effect seen on soft xrays at .22 to .23 sec

Jul 30 1993 01:33:24:430PM 930730013 Joseph Snipes Shot 13
O.K. shot

Jul 30 1993 01:42:04:080PM 930730014 Joseph Snipes Shot 14
Increasing proportional gain on ZCUR from 0.4 to 0.6. Increased RCUR prop. gain
from 2 to 3 starting at 100 ms.
Decent shot.

Jul 30 1993 01:59:12:290PM 930730014 Martin Greenwald Good Shot
Ip = .47 MA
Never mind on the MHD; This is a result of Granetz's batch job, which changed the
digitization rate.

Jul 30 1993 02:01:49:540PM 930730014 Joseph Snipes Shot 14
Increasing proportional gain on ZCUR from 0.4 to 0.6. Increased RCUR prop. gain
from 2 to 3 starting at 100 ms.
Decent shot.

Jul 30 1993 02:04:27:100PM 930730015 Joseph Snipes Shot 15
Increasing gain on RCUR from 0.1 s on for EF3.
Decent shot.

Jul 30 1993 02:35:33:260PM 930730015 Martin Greenwald Good Shot again
Fringe lost on at least one density channel

Jul 30 1993 02:35:46:160PM 930730016 Martin Greenwald Good Shot again

Jul 30 1993 02:37:43:800PM 930730016 Joseph Snipes Shot 16
Increasing gas from A side at 150 msec to raise the density and also increased
Ar slightly to increase HIREX signals.
Decent shot.

Jul 30 1993 03:01:13:050PM 930730017 Joseph Snipes Shot 17
Decreasing gas from A side at 150 msec but, then increasing it at 170 ms with a
short puff followed by another puff at 230 ms to raise the density.
Decent shot.

Jul 30 1993 03:02:55:080PM 930730017 Joseph Snipes Shot 18
Changed gas from A side to 4 short gas puffs and zeroed gas from B side upper
after 27 ms.
Decent shot.

Jul 30 1993 05:12:38:260PM 930730017 Martin Greenwald Good Startup
Disrupts halfway through

Jul 30 1993 03:03:14:670PM 930730018 Joseph Snipes Shot 18
Changed gas from A side to 4 short gas puffs and zeroed gas from B side upper
after 27 ms.
Decent shot.

Jul 30 1993 03:14:15:890PM 930730018 Martin Greenwald Good Shot again
Record Ip - .503 MA

Jul 30 1993 03:37:26:850PM 930730019 Joseph Snipes Shot 19
Changed gas from A side to 4 short gas puffs and zeroed gas from B side upper
after 27 ms.
Decent shot.

Jul 30 1993 05:13:15:770PM 930730019 Martin Greenwald Good Shot
No ECE

Jul 30 1993 03:53:40:330PM 930730020 Joseph Snipes Shot 20
Changed gas puffs a bit.
Decent shot, but radiated power high toward the end.
Disrupted.

Jul 30 1993 05:13:48:750PM 930730020 Martin Greenwald Good Startup - disrupts half way
No ECE

Jul 30 1993 04:00:35:140PM 930730021 Joseph Snipes Shot 21
Reduced Ar puff a bit. Increased H puffs at 60 and 85 ms.
Dud after the previous disruption.

Jul 30 1993 05:14:24:410PM 930730021 Martin Greenwald Dud

Jul 30 1993 04:05:59:290PM 930730022 Joseph Snipes Shot 22
Try again. Dud again.

Jul 30 1993 05:14:39:170PM 930730022 Martin Greenwald Dud

Jul 30 1993 04:16:51:290PM 930730023 Joseph Snipes Shot 23
Increasing prefill to 1.2 x 10**-5 Torr.
Decent shot.

Jul 30 1993 04:28:27:770PM 930730023 Martin Greenwald Good Shot - After several duds

Jul 30 1993 04:33:28:340PM 930730024 Joseph Snipes Shot 24
Decreasing prefill to 1.0 x 10**-5 Torr.
Decent shot.

Jul 30 1993 04:43:15:920PM 930730024 Martin Greenwald Good Shot
No ECE

Jul 30 1993 04:58:58:220PM 930730025 Martin Greenwald Dud

Jul 30 1993 04:59:08:180PM 930730025 Joseph Snipes Shot 25
Increased proportional gain on RCUR from 3 to 5 after 100 ms.
Also increased H gas puffs a bit.
Dud.

Physics Operator Comments

Engineering Operator Comments

Shot Time Type Status Comment

1 09:47:34:890AM Plasma Ok no faults -- no plasma

2 10:18:46:260AM Plasma Ok no faults -- no plasma

3 10:31:54:710AM Plasma Ok no faults -- no plasma

4 10:44:53:090AM Plasma Ok no faults -- first plasma

5 11:00:10:030AM Plasma Ok no faults -- fizzle

6 11:15:54:150AM Plasma Ok no faults -- no plasma

7 11:27:32:000AM Plasma Ok no faults -- no plasma

8 11:44:58:490AM Plasma Bad ef1 u+l comm fail -- supply voltage does not hold in inversion

9 12:04:55:140PM Plasma Ok no faults -- no plasma

10 12:28:03:170PM Plasma Ok no faults

11 12:42:40:900PM Plasma Ok no faults

12 12:54:33:450PM Plasma Ok no faults

13 01:15:33:510PM Plasma Ok no faults 450ka, almost 0.5sec plasma!!!!

14 01:37:52:980PM Plasma Ok no faults good plasma again

15 01:59:36:600PM Plasma Ok no faults -- plasma >0.5sec

16 02:17:43:990PM Plasma Ok no faults -- plasma

17 02:39:25:390PM Plasma Ok no faults

18 03:00:14:180PM Plasma Ok no faults

19 03:22:29:080PM Plasma Ok no faults

20 03:37:57:250PM Plasma Ok no faults

21 03:54:25:720PM Plasma Ok no faults

22 04:03:45:860PM Plasma Ok no faults

23 04:14:43:500PM Plasma Ok no faults

24 04:30:23:020PM Plasma Ok no faults

25 04:54:16:830PM Plasma Ok no faults

Session Leader Comments
Jul 30 1993 09:46:45:710AM		Joseph Snipes	Ohmic Transport Run Scaling of density at fixed current around 400 to 450 kA starting with 930729025, which was a good shot from yesterday. Argon will be added to get ion temperatures from HIREX. Otherwise, attempting stable reproducible plasmas.
Jul 30 1993 10:04:32:040AM	930730001	Martin Greenwald	Start by trying to repeat 930729025 Fizzle
Jul 30 1993 10:30:22:720AM	930730001	Joseph Snipes	Shot 1 Starting with 930729025 except moving Ar puff from 0 to -100 ms. Reduced H gas around 200 ms to attempt to flatten the density after 200 ms. Flash, but no current rise
Jul 30 1993 10:30:40:880AM	930730001	Joseph Snipes	Shot 2 Starting with 930729025 except moving Ar puff from 0 to -100 ms. Reduced H gas around 200 ms to attempt to flatten the density after 200 ms. Flash, but no current rise
Jul 30 1993 10:31:08:270AM	930730002	Joseph Snipes	Shot 2 Repeat. Same.
Jul 30 1993 10:37:47:960AM	930730002	Joseph Snipes	Shot 3 Moved Ar puff to -50 ms and reduced it a bit after the initial puff. Moved start of Bay A side gas puff to 18 ms. Reduced prefill to 1.2 x 10**-5 Torr. Wimper!
Jul 30 1993 10:44:21:880AM	930730002	Martin Greenwald	Fizzle
Jul 30 1993 10:41:38:050AM	930730003	Joseph Snipes	Shot 3 Moved Ar puff to -50 ms and reduced it a bit after the initial puff. Moved start of Bay A side gas puff to 18 ms. Reduced prefill to 1.2 x 10**-5 Torr. Wimper!
Jul 30 1993 10:44:31:650AM	930730003	Martin Greenwald	Fizzle
Jul 30 1993 10:55:46:050AM	930730004	Martin Greenwald	Good startup, disrupts at .175 sec, .3 MA
Jul 30 1993 11:04:38:110AM	930730005	Joseph Snipes	Shot 5 EF2U current program copied into EF2L program to balance those coils. Also notch removed from the gain on ZCUR wire 2 that was put is several days ago by Horne for the EFC. Dud!
Jul 30 1993 11:05:17:030AM	930730005	Martin Greenwald	Fizzle
Jul 30 1993 11:23:33:160AM	930730006	Joseph Snipes	Shot 6 Increased prefill to 1.2 x 10**-5 Torr. Dud!
Jul 30 1993 11:30:51:580AM	930730006	Martin Greenwald	Dud
Jul 30 1993 11:30:59:670AM	930730007	Martin Greenwald	Dud
Jul 30 1993 11:45:25:450AM	930730007	Joseph Snipes	Shot 7 Decreased prefill to 9 x 10**-6 Torr. Took out imbalance that had been programmed in EF2 by reducing EF2L by 40 A to 1710 A at commutation.
Jul 30 1993 11:47:34:780AM	930730008	Martin Greenwald	Fizzle
Jul 30 1993 11:49:50:500AM	930730008	Joseph Snipes	Shot 8 Increased prefill to 1.3 x 10**-5 Torr. Fizzle!
Jul 30 1993 11:58:09:150AM	930730008	Joseph Snipes	Shot 8 Commutation failure in EF1 supply.
Jul 30 1993 12:12:48:010PM	930730009	Martin Greenwald	Dud
Jul 30 1993 12:27:04:010PM	930730009	Joseph Snipes	Shot 9 Reduced EF2L by 10 A to 1700 A to balance with EF2U. Dud!
Jul 30 1993 12:41:00:460PM	930730010	Joseph Snipes	Shot 10 Increased prefill to 1.4 x 10**-5 Torr. Fizzle!
Jul 30 1993 05:05:35:090PM	930730010	Martin Greenwald	Fizzle
Jul 30 1993 12:48:56:790PM	930730011	Joseph Snipes	Shot 11 Increased gas puff from Bay A side early at -10 ms. Fizzle.
Jul 30 1993 05:05:43:260PM	930730011	Martin Greenwald	Fizzle
Jul 30 1993 12:59:27:510PM	930730012	Joseph Snipes	Shot 12 Decreased prefill to 1 x 10**-5 Torr. fizzle
Jul 30 1993 05:05:56:600PM	930730012	Martin Greenwald	Fizzle
Jul 30 1993 01:29:49:540PM	930730013	Martin Greenwald	Good Shot Ip = .46 nel = .5^20 Very Interesting MHD effect seen on soft xrays at .22 to .23 sec
Jul 30 1993 01:33:24:430PM	930730013	Joseph Snipes	Shot 13 O.K. shot
Jul 30 1993 01:42:04:080PM	930730014	Joseph Snipes	Shot 14 Increasing proportional gain on ZCUR from 0.4 to 0.6. Increased RCUR prop. gain from 2 to 3 starting at 100 ms. Decent shot.
Jul 30 1993 01:59:12:290PM	930730014	Martin Greenwald	Good Shot Ip = .47 MA Never mind on the MHD; This is a result of Granetz's batch job, which changed the digitization rate.
Jul 30 1993 02:01:49:540PM	930730014	Joseph Snipes	Shot 14 Increasing proportional gain on ZCUR from 0.4 to 0.6. Increased RCUR prop. gain from 2 to 3 starting at 100 ms. Decent shot.
Jul 30 1993 02:04:27:100PM	930730015	Joseph Snipes	Shot 15 Increasing gain on RCUR from 0.1 s on for EF3. Decent shot.
Jul 30 1993 02:35:33:260PM	930730015	Martin Greenwald	Good Shot again Fringe lost on at least one density channel
Jul 30 1993 02:35:46:160PM	930730016	Martin Greenwald	Good Shot again
Jul 30 1993 02:37:43:800PM	930730016	Joseph Snipes	Shot 16 Increasing gas from A side at 150 msec to raise the density and also increased Ar slightly to increase HIREX signals. Decent shot.
Jul 30 1993 03:01:13:050PM	930730017	Joseph Snipes	Shot 17 Decreasing gas from A side at 150 msec but, then increasing it at 170 ms with a short puff followed by another puff at 230 ms to raise the density. Decent shot.
Jul 30 1993 03:02:55:080PM	930730017	Joseph Snipes	Shot 18 Changed gas from A side to 4 short gas puffs and zeroed gas from B side upper after 27 ms. Decent shot.
Jul 30 1993 05:12:38:260PM	930730017	Martin Greenwald	Good Startup Disrupts halfway through
Jul 30 1993 03:03:14:670PM	930730018	Joseph Snipes	Shot 18 Changed gas from A side to 4 short gas puffs and zeroed gas from B side upper after 27 ms. Decent shot.
Jul 30 1993 03:14:15:890PM	930730018	Martin Greenwald	Good Shot again Record Ip - .503 MA
Jul 30 1993 03:37:26:850PM	930730019	Joseph Snipes	Shot 19 Changed gas from A side to 4 short gas puffs and zeroed gas from B side upper after 27 ms. Decent shot.
Jul 30 1993 05:13:15:770PM	930730019	Martin Greenwald	Good Shot No ECE
Jul 30 1993 03:53:40:330PM	930730020	Joseph Snipes	Shot 20 Changed gas puffs a bit. Decent shot, but radiated power high toward the end. Disrupted.
Jul 30 1993 05:13:48:750PM	930730020	Martin Greenwald	Good Startup - disrupts half way No ECE
Jul 30 1993 04:00:35:140PM	930730021	Joseph Snipes	Shot 21 Reduced Ar puff a bit. Increased H puffs at 60 and 85 ms. Dud after the previous disruption.
Jul 30 1993 05:14:24:410PM	930730021	Martin Greenwald	Dud
Jul 30 1993 04:05:59:290PM	930730022	Joseph Snipes	Shot 22 Try again. Dud again.
Jul 30 1993 05:14:39:170PM	930730022	Martin Greenwald	Dud
Jul 30 1993 04:16:51:290PM	930730023	Joseph Snipes	Shot 23 Increasing prefill to 1.2 x 10**-5 Torr. Decent shot.
Jul 30 1993 04:28:27:770PM	930730023	Martin Greenwald	Good Shot - After several duds
Jul 30 1993 04:33:28:340PM	930730024	Joseph Snipes	Shot 24 Decreasing prefill to 1.0 x 10**-5 Torr. Decent shot.
Jul 30 1993 04:43:15:920PM	930730024	Martin Greenwald	Good Shot No ECE
Jul 30 1993 04:58:58:220PM	930730025	Martin Greenwald	Dud
Jul 30 1993 04:59:08:180PM	930730025	Joseph Snipes	Shot 25 Increased proportional gain on RCUR from 3 to 5 after 100 ms. Also increased H gas puffs a bit. Dud.

Engineering Operator Comments
Shot	Time	Type	Status	Comment
1	09:47:34:890AM	Plasma	Ok	no faults -- no plasma
2	10:18:46:260AM	Plasma	Ok	no faults -- no plasma
3	10:31:54:710AM	Plasma	Ok	no faults -- no plasma
4	10:44:53:090AM	Plasma	Ok	no faults -- first plasma
5	11:00:10:030AM	Plasma	Ok	no faults -- fizzle
6	11:15:54:150AM	Plasma	Ok	no faults -- no plasma
7	11:27:32:000AM	Plasma	Ok	no faults -- no plasma
8	11:44:58:490AM	Plasma	Bad	ef1 u+l comm fail -- supply voltage does not hold in inversion
9	12:04:55:140PM	Plasma	Ok	no faults -- no plasma
10	12:28:03:170PM	Plasma	Ok	no faults
11	12:42:40:900PM	Plasma	Ok	no faults
12	12:54:33:450PM	Plasma	Ok	no faults
13	01:15:33:510PM	Plasma	Ok	no faults 450ka, almost 0.5sec plasma!!!!
14	01:37:52:980PM	Plasma	Ok	no faults good plasma again
15	01:59:36:600PM	Plasma	Ok	no faults -- plasma >0.5sec
16	02:17:43:990PM	Plasma	Ok	no faults -- plasma
17	02:39:25:390PM	Plasma	Ok	no faults
18	03:00:14:180PM	Plasma	Ok	no faults
19	03:22:29:080PM	Plasma	Ok	no faults
20	03:37:57:250PM	Plasma	Ok	no faults
21	03:54:25:720PM	Plasma	Ok	no faults
22	04:03:45:860PM	Plasma	Ok	no faults
23	04:14:43:500PM	Plasma	Ok	no faults
24	04:30:23:020PM	Plasma	Ok	no faults
25	04:54:16:830PM	Plasma	Ok	no faults