Miniproposals

Miniproposal: 222 Date Filed: 1/13/1999 Title: Impurity Compression and Enrichment Studies First Author: John Goetz Session Leader: John Goetz (shots 1-27)

Engineering Operator Run Comment

MP#241/Wolfe/Silva

Session Leader Plans

Physics Operators Plans

Session Leader Summaries

Entered: Jul 7 2004 03:49:20:350PM

Author: To Be Determined

Run 990429 -- MP #222 Impurity Compression and Enrichment This proposal is an attempt to extend the compression and enrichment database to gases other than argon and investigate the effect of the divertor bypass on impurity behavior. It was also hoped that that argon compression scaling with density in Ohmic plasmas from the 1997-98 run campaign could be reproduced. This part of the run is a continuation of the 1/2 run from 990305. The physics plan is to: 1. Fill in the density scan that was begun on 990305 with puffed argon and krypton in Ohmic plasmas. Start with a density that was already done and fill in some missing points with the divertor bypass closed. 2. Open the divertor bypass and perform the same density scan. 3. Perform dynamic bypass operation, e.g. closed->open, at various densities. Physics Summary: The run was successful in covering the above points. Argon and krypton were puffed into Ohmic plasmas with nl04 ranging from 0.67 x 10^20 to 1.48 x 10^20 with Ip=0.8MA. The detachment threshold for these plasmas was determined to be ~1.25 x 10^20. The scaling of argon compression with density is similar to that obtained in the 990305B run. These compression values are reduced by a factor of ~2 from the previous run campaign. The krypton data are yet to be analyzed. The core krypton levels are awaiting some modelling. The deuterium compression also scales with density in a way similar to that observed in the previous run campaign. The value of the deuterium compression is reduced by ~25%. Taken together with the argon compression results, this seems to indicate that the divertor is not as "closed" as in the previous run campaign. The divertor bypass does indeed have an effect on the impurity behavior. The difference on the argon compression with the bypass open and bypass closed is a factor of about two. The compression is higher with the bypass closed. This is due to less argon in the core and more argon in the divertor. The deuterium compression is also about two times lower with the bypass open. Detachment reduces the impurity compression greater than a factor of two. After detachment occurs, the deuterium compression remains constant at the pre-detachment level. Both of these observations are similar to those seen in the 1998 run campaign. The bypass was opened during a discharge at varying densities (see shots 023, 024, 025, and 027). At very low density, nl04=0.67 x 10^20 the bypass does not appear to have any effect on the impurity levels in the core and the divertor, and thus the impurity compression remains constant. At medium density, nl04=0.84 x 10^20, opening the bypass during the shot decreases the impurity compression by ~2.5x. This is due both to an increase in the core concentration and a reduction in the divertor impurity concentration. At high density, nl04=1.1 x 10^20, opening the bypass causes the divertor plasma to detach. The combination of open bypass and detachment results in the argon compression being reduced by a factor of ~6. Some other observations made today: (a) The "pump-out" effect on the core impurity levels is still present. This would seem to indicate that these gases are not fully recycling. The magnitude of the "pump-out" effect seems to depend on density. (b) An attempt was made to look for the krypton source on the midplane using KrII lines - none were observed. These observations along with modelling of the krypton data are still under investigation. This was a good finish to the Ohmic portion of MP222. The detailed shot log follows: Shot Result ---- ------ 001 no power supplies 002 fizzle 003 plasma - no Ar puff; no Kr puff; strike points in the slot 004 plasma - Ar and Kr puffs; bypass closed; strike points in the slot; nl04=1.07e20 005 fizzle 006 plasma - Ar and Kr puffs; HIREX problems; nl04=1.08e20; bypass closed 007 fizzle 008 fizzle 009 plasma - Ar and Kr puffs; nl04=1.1e20; bypass open; 010 plasma - Ar and Kr puffs; nl04=1.48e20; bypass open; detached @ 0.5s 011 plasma - Ar and Kr puffs; nl04=1.43e20; bypass closed; detached @ 0.53s 012 plasma - Ar and Kr puffs; nl04=1.20->1.35e20; bypass closed; detaches @ 1.05s 013 plasma - Ar and Kr puffs; nl04=1.16->1.32e20; bypass closed; detaches @ 1.14s 014 plasma - Ar and Kr puffs; nl04=1.21e20; bypass closed; very slight and slow detachment 015 fizzle 016 plasma - Ar and Kr puffs; nl04=1.23e20; bypass open; detaches after 1.1s 017 plasma - Ar and Kr puffs; nl04=1.08e20; bypass open; 018 plasma - Ar and Kr puffs; nl04=0.94e20; bypass open; no EFIT or McP 019 plasma - Ar and Kr puffs; nl04=0.96e20; bypass open; 020 plasma - Ar and Kr puffs; nl04=0.78e20; bypass open; 021 plasma - Ar and Kr puffs; nl04=0.71e20; bypass open; 022 plasma - Ar and Kr puffs; nl04=0.74e20; bypass closed; 023 plasma - Ar and Kr puffs; nl04=0.67->0.76e20; bypass closed->open at 0.9s 024 plasma - Ar and Kr puffs; nl04=1.1->1.48e20; bypass closed->open @ 0.9s detaches right after bypass opens 025 plasma - Ar and Kr puffs; nl04=1.0->1.25e20; bypass closed->open @ 0.9s detaches after bypass opens 026 plasma - Ar and Kr puffs; nl04=0.85e20; bypass closed 027 plasma - Ar and Kr puffs; nl04=0.84->0.89; bypass closed->open @ 0.9s

Physics Operator Summaries

Entered: Jul 7 2004 04:37:01:147PM

Author: To Be Determined

Physop Summary for Thursday, 29 April, 1999 Physop: R. Parker Session Leader: J. Goetz The run was restricted to ohmic shots since the RF was not available. The machine ran well without any glitches. Two observations. It is important to run Coldstart at the beginning of the run. Due to lack of air conditioning in the control room, there were computer problems before this run. Although Coldstart was not run by the Physop it was caught before the first shot (but after INIT) by an alert R. Granetz. The second is to use segment one startup from a recent previous shot, rather than from an old shot that the Session Leader might request. The reason is that startup conditions vary slowly over time and in a way in which they are automatically tracked by small day-to-day changes. Scorecard: 21 useful discharges, 5 fizzles and 1 no plasma due to operator error.

Session Leader Comments
Apr 29 1999 09:30:32:327AM		John Goetz	Run 990429 This run is in support of MiniProposal 222 - Impurity Compression and Enrichment Measurements This run will gather some more argon and krypton concentration data. The core density will be varied and the bypass position (open vs. closed) will be changed while monitoring impurity levels in the core and the divertor. The holes in the data obtained 990305 will be filled in.
Apr 29 1999 09:50:19:983AM	990429002	John Goetz	Shot 990429002: Reload 990305023 Results: Fizzle
Apr 29 1999 10:19:57:000AM	990429003	John Goetz	Shot 990429003: Reload 990305023 Results: Plasma no Ar and no Kr puffed for a baseline shot nl04 = 1.1 e20 slot divertor until about 0.95s
Apr 29 1999 10:40:34:403AM	990429004	John Goetz	Shot 990429004: enable the Ar and Kr puffs Results: Plasma Ar (0.3s) and Kr (0.37s) puffed nl04 = 1.1 e20 slot divertor until about 0.57s
Apr 29 1999 10:55:50:750AM	990429005	John Goetz	Shot 990429005: open the bypass for the whole shot Results: fizzle
Apr 29 1999 11:12:30:387AM	990429006	John Goetz	Shot 990429006: open the bypass for the whole shot Results: plasma Ar and Kr puffed bypass opened for the whole shot 2x krypton in the core compared to 004 no argon data obtained - HIREX 1 had trouble
Apr 29 1999 11:34:37:420AM	990429007	John Goetz	Shot 990429007: try a repeat of 006 to get core argon data Results: fizzle
Apr 29 1999 11:49:25:233AM	990429008	John Goetz	Shot 990429008: try a repeat of 006 to get core argon data Results: fizzle
Apr 29 1999 12:01:03:827PM	990429009	John Goetz	Shot 990429009: try a repeat of 006 to get core argon data Results: plasma bypass open nl04 = 1.1e20 Kr and Ar puffed - all measurements made
Apr 29 1999 12:21:22:983PM	990429010	John Goetz	Shot 990429010: raise the density and try to achieve detachment Results: plasma bypass open nl04 = 1.5e20 Kr and Ar puffed - all measurements made detachment occurs @ 0.5s
Apr 29 1999 12:36:10:373PM	990429011	John Goetz	Shot 990429011: detachment with bypass closed Results: plasma bypass closed nl04 = 1.5e20 Kr and Ar puffed - all measurements made detachment occurs @ 0.53s
Apr 29 1999 12:58:24:997PM	990429012	John Goetz	Shot 990429012: just below detachment with bypass closed Results: plasma bypass closed nl04 = 1.2 -> 1.35e20 Kr and Ar puffed - all measurements made begins to detach @ 1.05s
Apr 29 1999 01:09:21:000PM	990429013	John Goetz	Shot 990429013: just below detachment with bypass closed Results: plasma bypass closed nl04 = 1.17 -> 1.32e20 Kr and Ar puffed - all measurements made begins to detach @ 1.05s
Apr 29 1999 01:30:16:217PM	990429014	John Goetz	Shot 990429014: ramp the density down just below detachment with bypass closed Results: plasma bypass closed nl04 = 1.21e20 Kr and Ar puffed - all measurements made very slow detachment begins @ 1.1s
Apr 29 1999 01:38:05:200PM	990429015	John Goetz	Shot 990429015: just below detachment with bypass open Results: fizzle
Apr 29 1999 02:06:54:653PM	990429016	John Goetz	Shot 990429016: just below detachment with bypass open Results: plasma Ar and Kr puffs bypass open nl04 = 1.19e20 some unknown injection @ 0.63s
Apr 29 1999 02:21:27:217PM	990429017	John Goetz	Shot 990429017: density scan with bypass open Results: plasma Ar and Kr puffs bypass open nl04 = 1.08e20
Apr 29 1999 02:36:51:000PM	990429018	John Goetz	Shot 990429018: density scan with bypass open Results: plasma Ar and Kr puffs bypass open nl04 = 0.94e20
Apr 29 1999 02:53:49:000PM	990429019	John Goetz	Shot 990429019: density scan with bypass open repeat 018 because of missing EFIT and McPherson data Results: plasma Ar and Kr puffs bypass open nl04 = 0.96e20
Apr 29 1999 03:09:37:450PM	990429020	John Goetz	Shot 990429020: density scan with bypass open Results: plasma Ar and Kr puffs bypass open nl04 = 0.78e20
Apr 29 1999 03:28:10:687PM	990429021	John Goetz	Shot 990429021: density scan with bypass open Results: plasma Ar and Kr puffs bypass open nl04 = 0.71e20
Apr 29 1999 04:08:51:390PM	990429022	John Goetz	Shot 990429022: density scan with bypass closed Results: plasma Ar and Kr puffs bypass closed nl04 = 0.74e20
Apr 29 1999 04:07:32:950PM	990429023	John Goetz	Shot 990429023: bypass closed -> open at low density Results: plasma Ar and Kr puffs bypass closed->open at 0.9s nl04 = 0.67->0.76e20
Apr 29 1999 04:29:00:000PM	990429024	John Goetz	Shot 990429024: bypass closed->open at "high" density Results: plasma Ar and Kr puffs bypass closed->open at 0.9s nl04 = 1.1->1.48e20 detaches right after the bypass opens
Apr 29 1999 04:46:28:030PM	990429025	John Goetz	Shot 990429025: bypass closed->open at "high" density Results: plasma Ar and Kr puffs bypass closed->open at 0.9s nl04 = 1.0->1.25e20 detaches right after the bypass opens??
Apr 29 1999 04:59:45:780PM	990429026	John Goetz	Shot 990429026: density scan with bypass closed Results: plasma Ar and Kr puffs bypass closed nl04 = 0.85e20
Apr 29 1999 05:14:51:607PM	990429027	John Goetz	Shot 990429027: bypass closed->open at "medium" density Results: plasma Ar and Kr puffs bypass closed->open at 0.9s nl04 = 0.84->0.89e20

Physics Operator Comments
Apr 29 1999 10:41:54:827AM	990429001	Ron Parker	Shot 1 was aborted since Coldstart had not been run before shot had entered INIT.
Apr 29 1999 10:43:17:640AM	990429002	Ron Parker	Shot 2 failed because BR was too negative, less than 3.5 mT.
Apr 29 1999 10:45:01:983AM	990429003	Ron Parker	Shot 3 went as planned, but disrupted early in rampdown. The elongation here is a little high.
Apr 29 1999 10:46:11:547AM	990429004	Ron Parker	X-point raised 5 mm. Shot went, but current rise was delayed.
Apr 29 1999 10:55:24:217AM	990429005	Ron Parker	Shot 5 was a fizzle. Fill pressure was raised to improve current rise. Suspect BR still too negative.
Apr 29 1999 12:05:52:653PM	990429006	Robert Granetz	Shot 06 -- Plasma. 0.8 MA, ohmic, disrupted at 1.28 s. Kappa=1.71, inner gap=1.5 cm, outer gap=1.7-1.8 cm. Next shot: increase RCUR by 1.5 mm, which should decrease outer gap to 1.4-1.5 cm and reduce elongation. Also increase Br offset by another 0.5 mT There is a delay between this shot and the next shot because John Goetz needs cell access. Also some work on the diborane alarm system.
Apr 29 1999 11:37:48:623AM	990429007	Robert Granetz	Shot 07 -- Fizzle. Next shot: load segment 1 from last shot on Tuesday, (Ron had loaded the entire shot from last March), except set the Br offset to +0.001 T (arbitrary guess).
Apr 29 1999 11:43:10:280AM	990429008	Robert Granetz	Shot 08 -- Fizzle. Br way too negative. Next shot: increase Br offset by 0.0025 T (to 0.0035 T)
Apr 29 1999 12:06:16:763PM	990429009	Robert Granetz	Shot 09 -- Plasma. 0.8 MA, ohmic, good shot. NL_04=1.1e20 m-2. Next shot: increase density to NL_04=1.35e20 m-2.
Apr 29 1999 12:12:27:297PM	990429010	Robert Granetz	Shot 10 -- Plasma. 0.8 MA, ohmic, NL_04=1.45-1.35e20 m-2 Next shot: no PCS changes. Increase He4 pressure in the Ninja plenum from 2 psi to 4 psi.
Apr 29 1999 12:34:08:200PM	990429011	Ron Parker	Good shot. Next shot ne = 1.2x10**20.
Apr 29 1999 12:52:55:733PM	990429012	Ron Parker	Shot ran as planned, with density lowered to ~1.2x10^14. Next shot: lower density to 1.15x10^14, no other changes.
Apr 29 1999 01:14:02:840PM	990429013	Ron Parker	Shot ran, but still a slight rise in density as plasma trries to detach. Next shot: lower density to 1.1x10^14.
Apr 29 1999 01:37:07:967PM	990429014	Ron Parker	Shot ran as planned. Density stayed lower than detachment threshhold. Next shot: lower ZCUR by 3 mm
Apr 29 1999 01:45:42:500PM	990429015	Ron Parker	Fizzle. Next shot: Drop BR by 0.5 mT
Apr 29 1999 02:18:13:827PM	990429015	Ron Parker	Shot ran as programmed. Next shot: density lowered to 0.9x10^14.
Apr 29 1999 02:59:20:340PM	990429016	Ron Parker	Shot ran as planned. Lowering BR .5 mT seemed to help. Next shot: Initial fill lowered about 10%, density set to 1.0x10^14 and RX moved out 3 mm ~linearly during shot.
Apr 29 1999 02:59:59:750PM	990429017	Ron Parker	Shot ran as planned. Next shot: n=0.8x10^14.
Apr 29 1999 02:45:28:437PM	990429018	Ron Parker	Changed plan, since no magnetics on last shot. Repeat n=0.9x10^14.
Apr 29 1999 02:50:42:153PM	990429019	Ron Parker	Shot ran as planned, density a little higher than 0.9x10^14. Next: n=0.75x10^14.
Apr 29 1999 03:12:26:590PM	990429020	Ron Parker	Shot 20 ran as planned. Next shot is set for n=6.2x10^13.
Apr 29 1999 03:28:53:873PM	990429021	Ron Parker	Shot ran as planned, density a little higher than programmed. Next shot, same settings as in 21, but flapper closed.
Apr 29 1999 03:45:24:403PM	990429022	Steve Wolfe	shot 22: Wolfe taking over for Parker - shot is repeat of 21 with flappers closed. No pcs changes. plasma ok. Next shot: No pcs changes.
Apr 29 1999 04:03:59:700PM	990429023	Steve Wolfe	shot 23: No pcs changes. csp will flap in the middle of the shot. plasma ok. Next shot: 1.1e20
Apr 29 1999 04:25:58:310PM	990429024	Steve Wolfe	shot 24: nl04->1.1e20, raise pg3 maint level from 20-30V. plasma ok; nl4=1.1 until flap time, then rises to 1.5 next shot, nl04 ->1.0e20
Apr 29 1999 04:39:57:060PM	990429025	Steve Wolfe	shot 25: nl04->1.0e20 plasma ok, gets 1.0, then rises to 1.25 at the flap. next shot: 8.2e19
Apr 29 1999 04:54:10:687PM	990429026	Steve Wolfe	shot 26: nl04->8.2e19, PG3 maint back to 20V. plasma, ok. Parker back in the chair for last shot.

Engineering Operator Comments
Shot	Time	Type	Status	Comment
1	09:22:07:217AM	Test	Ok	no power cycle/oka
2	09:42:22:717AM	Plasma	Ok	No faults fizzle
3	10:01:27:090AM	Plasma	Ok	No Faults
4	10:26:56:170AM	Plasma	Ok	No faults
5	10:45:48:547AM	Plasma	Ok	No faults
6	10:59:12:857AM	Plasma	Ok	No faults
7	11:22:32:763AM	Plasma	Ok	No faults
8	11:37:24:623AM	Plasma	Ok	No faults
9	11:50:33:840AM	Plasma	Ok	No faults
10	12:03:59:200PM	Plasma	Ok	No faults
11	12:21:48:640PM	Plasma	Ok	No faults
12	12:45:47:717PM	Plasma	Ok	No faults
13	12:59:19:810PM	Plasma	Ok	No faults
14	01:17:19:780PM	Plasma	Ok	No Faults
15	01:33:44:437PM	Plasma	Ok	No Faults
16	01:49:46:763PM	Plasma	Bad	Faults in OH1 and EF1 supplies
17	02:09:35:687PM	Plasma	Ok	No Faults
18	02:24:14:403PM	Plasma	Ok	No Faults
19	02:45:28:140PM	Plasma	Ok	No Faults
20	03:01:01:637PM	Plasma	Ok	No Faults
21	03:21:11:013PM	Plasma	Ok	no faults
22	03:42:44:043PM	Plasma	Ok	no faults
23	03:58:55:107PM	Plasma	Ok	No Faults
24	04:16:32:933PM	Plasma	Ok	No Faults
25	04:36:11:077PM	Plasma	Ok	No Faults
26	04:52:28:140PM	Plasma	Ok	No Faults
27	05:10:26:547PM	Plasma	Ok	No Faults