Miniproposals

Miniproposal: Date Filed: Title: First Author: Session Leader: Chris Rost (shots 1-9) Session Leader: John Reardon (shots 1-9)

Engineering Operator Run Comment

snipe

Session Leader Plans

Physics Operators Plans

Session Leader Summaries

Physics Operator Summaries

Entered: Jul 7 2004 04:36:56:147PM

Author: To Be Determined

Physics operator's summary for run 960220: MP #141, RF edge physics. SL: Rost/Reardon PO: Granetz (last minute swap with Joe Snipes) EO: V. Bertolino Today's run will study the parametric decay of RF waves at the edge of the plasma. This is most easily studied at low fields in L-mode. About four shots at each of three fields (2.75, 3.40, and 3.00 T) will be required. The plasma current will be 0.55 MA. The plasma composition will be 7.5% H and 92.5% D. RF power will be varied in steps from 0.1 to 0.8 MW. Summary: The start of this run was delayed until 11:30, due to problems with the circuit boards controlling the piezoelectric gas puffing valves. The temporary replacement board may have had something to do with initial difficulty in establishing the current rise. After only one successful plasma shot, the EF1's blew SCR's and circuit breakers and could not be fixed in time to continue the run. It was a complete washout as far as MP #141 is concerned. Neither repairs to the main fueling valve chopper board, nor repairs to the PF supplies had been effected by the end of today. Scorecard: 1 plasmas 4 fizzles 1 tests 3 duds (due to power supply problems) ---------- 9 total Run plan: (1) OH test (2) Fiducial shot (from 960201001), except plasma has 7.5% hydrogen component (3) Start MP. Load from a low-field shot (960118032), except set hybrid control of toroidal field at 2.75 tesla (I_tf = -2.75 x 27.95 kA - 3 kA). Engineering setup for Tuesday 20 Feb 1996: Boronization overnight prior to this run Discharge clean in helium for a couple of hours before the run. NOTE: this was not done, due to problems with the control of the gas valves. A-side (actually K-side) plenum: 1.5 psi of H2 and 18.5 psi of D2 B-top plenum: 5 psi of deuterium. B-side-lower plenum: 4 psi of argon. NINJA plenum: make sure this is pumped out. Enable hybrid control of A-side, B-top, and B-side-lower valves for start of run. Enable the ECE, VUV, Moly monitor, PCX, and TCX valves, assuming status of each is okay. Use engineering settings from shot 960201001 (a fiducial shot). After the fiducial, we will ask for the engineering settings from shot 960118032 (a 2.6 tesla, 550 kA shot), and hybrid control of the TF. Detailed shot log: Shot 01 -- OH test (first shot of the week), and gas valve test. Because of problems with the usual circuit board that controls the main gas valve (the chopped control), we've had to reinstall the older proportional control. This has changed the valve response in the early breakdown and current rise phase, necessitating some tweaks to the early gas voltage programming. Shot 02 -- Fizzle (supposed to be a fiducial). Gas looks okay. Maybe a bit too much Br. Next shot: reduce Br offset by 0.5 mT. Shot 03 -- No TF. (Magnet resistance fault.) Shot 04 -- Fizzle. Next shot: tiny tweaks to Br offset and early gas puff. Shot 05 -- Fizzle. Next shot: reduce Br offset by 1 mT. Shot 06 -- Fizzle. Br finally looks better. Gas pressure at t=0 is about a factor 2 lower than at the end of last Friday. Next shot: increase pre-pulse puff from 10 to 12 ms, and tweak up the early gas puff some more. Shot 07 -- Plasma (fiducial). H-mode. Next shot: load in segment 2 from 960118032 (a 2.6 T, 550 kA shot). Adjust I_tf to get 2.75 T. I did this, rather than loading in the entire shot, because of the problems we've been having with the breakdown today. Shot 08 -- Dud. PF breaker pulled out at -1 s. Fuses blown. Shot 09 -- Dud. PF breaker pulled out at -1 s. Fuses blown, SCR's blown. End of run.

Session Leader Comments

Physics Operator Comments
Feb 20 1996 09:52:41:200AM		Robert Granetz	MP #141, RF edge physics. SL: Rost/Reardon PO: Granetz (last minute swap with Joe Snipes) EO: V. Bertolino Today's run will study the parametric decay of RF waves at the edge of the plasma. This is most easily studied at low fields in L-mode. About four shots at each of three fields (2.75, 3.40, and 3.00 T) will be required. The plasma current will be 0.55 MA. The plasma composition will be 7.5% H and 92.5% D. RF power will be varied in steps from 0.1 to 0.8 MW.
Feb 20 1996 09:53:45:560AM		Robert Granetz	Engineering setup for Tuesday 20 Feb 1996: Boronization overnight prior to this run Discharge clean in deuterium for a couple of hours before the run A-side (actually K-side) plenum: 1.5 psi of H2 and 18.5 psi of D2 B-top plenum: 5 psi of deuterium. B-side-lower plenum: 4 psi of argon. NINJA plenum: make sure this is pumped out. Enable hybrid control of A-side, B-top, and B-side-lower valves for start of run. Enable the ECE, VUV, Moly monitor, PCX, and TCX valves, assuming status of each is okay. Use engineering settings from shot 960201001 (a fiducial shot). After the fiducial, we will ask for the engineering settings from shot 960118032 (a 2.6 tesla, 550 kA shot), and hybrid control of the TF.
Feb 20 1996 10:17:39:290AM		Robert Granetz	Run plan: (1) OH test (2) Fiducial shot (from 960201001), except plasma has 7.5% hydrogen component (3) Start MP. Load from a low-field shot (960118032), except set hybrid control of toroidal field at 2.75 tesla
Feb 20 1996 11:46:56:340AM	960220001	Robert Granetz	Shot 01 -- OH test (first shot of the week), and gas valve test. Because of problems with the usual circuit board that controls the main gas valve (the chopped control), we've had to reinstall the older proportional control. This has changed the valve response in the early breakdown and current rise phase, necessitating some tweaks to the early gas voltage programming.
Feb 20 1996 11:56:39:100AM	960220002	Robert Granetz	Shot 02 -- Fizzle. Gas looks okay. Maybe a bit too much Br. Next shot: reduce Br offset by 0.5 mT.
Feb 20 1996 12:03:31:260PM	960220003	Robert Granetz	Shot 03 -- No TF. (Magnet resistance fault.)
Feb 20 1996 12:14:59:800PM	960220004	Robert Granetz	Shot 04 -- Fizzle. Next shot: tiny tweaks to Br offset and early gas puff.
Feb 20 1996 12:29:38:460PM	960220005	Robert Granetz	Shot 05 -- Fizzle. Next shot: reduce Br offset by 1 mT.
Feb 20 1996 12:46:51:280PM	960220006	Robert Granetz	Shot 06 -- Fizzle. Br finally looks better. Gas pressure at t=0 is about a factor 2 lower than at the end of last Friday. Next shot: increase pre-pulse puff from 10 to 12 ms, and tweak up the early gas puff some more.
Feb 20 1996 01:01:31:690PM	960220007	Robert Granetz	Shot 07 -- Plasma (fiducial). H-mode. Next shot: load in segment 2 from 960118032 (a 2.6 T, 550 kA shot). Adjust I_tf to get 2.75 T. I did this, rather than loading in the entire shot, because of the problems we've been having with the breakdown today.
Feb 20 1996 01:07:58:680PM	960220008	Robert Granetz	Shot 08 -- Dud. PF breaker pulled out at -1 s.
Feb 20 1996 03:21:56:050PM	960220009	Robert Granetz	Shot 09 -- Dud. PF breaker pulled out at -1 s. Fuses blown, SCR's blown.

Engineering Operator Comments
Shot	Time	Type	Status	Comment
1	11:32:50:580AM	Test	Ok
2	11:49:58:290AM	Plasma	Ok
3	12:00:05:550PM	Plasma	Bad	mag resist fault in pulse
4	12:07:06:850PM	Plasma	Ok
5	12:20:59:810PM	Plasma	Ok
6	12:38:40:080PM	Plasma	Ok
7	12:47:50:240PM	Plasma	Ok
8	01:04:53:110PM	Plasma	Bad	ef1l
9	01:53:26:020PM	Plasma	Bad	ef1l