| Miniproposals | ||||||||||
|
| Operators | |
| Session leader(s): | Jim Irby |
| Physics operator(s): | Steve Wolfe |
| Engineering operator(s): | Sam Pierson |
| Engineering Operator Run Comment |
| MP# 298a EO Pierson PO Wolfe SL Irby |
| Session Leader Plans |
| Entered: May 19 2005 08:06:07:303AM |
| Author: Jim Irby |
| We will start from the last successful shot from Friday, 5/6. If we get a couple
of good shots we will go to the ICRF 1 MA fiducial and start bringing up the rf. We will carefully monitor Ti lines, pressures, density control, etc. |
| Physics Operators Plans |
| Entered: May 18 2005 11:57:24:210AM |
| Author: Steve Wolfe |
Engineering setup for Thursday, 19 May 2005 Recovery from Vacuum Opening Nominal MP#298a "C-Mod Startup" Session leader: J. Irby Physics operator: S. Wolfe ECDC overnight in D2, 2e-4 Torr; bake at 60 C. Run begins at 09:00 and ends at 17:00. Power systems as on 1050506032 A-coil configuration: normal [+Dtop -Dbot -Jtop +Jbot] and enabled. Gas Setup: fill B-Top with 6 psi D2 Hybrid enabled (PG4) fill B-side lower with 1 psi Ar Hybrid DISabled (PG1) leave B-side upper with whatever Hybrid disabled fill B-main (B-side Main) with 40 psi D2 Hybrid enabled (PG3) Gate valves open on first shot, possibly closed at some point during the run. Enable the following gate valves, assuming no vacuum problems: ECE, VUV, Z-bolo shutters Necessary diagnostics: Titanium monitoring ------------------------------------------------------------------------------- ICRF Setup: All transmitters in run on at 8:30 ------------------------------------------------------------------------------ Run plan: --------- The plan is to contimue the operation that had been terminated on 1050506 in order to remove the LH grill. Of interest will be the level of Ti and the level of D2/H2 fueling from the wall. The first shot loaded will be copied from 1050506032. When and if the discharge approaches a "normal"state, a fidicial shot will be run, e.g. 1050429001. ICRF will attempt to re-condition the antennas. If we get reproducible shots, J. Terry will scan the VUV. |
| Session Leader Summaries |
| Entered: May 19 2005 05:28:21:787PM |
| Author: Jim Irby |
| The h/(h+d) was very good today considering the up-to-argon. Very low radiated power on the last two plasmas and h/(h+d) 10% or less. Cleanup is going well. |
| Physics Operator Summaries |
| Entered: May 19 2005 05:32:35:227PM |
| Author: Steve Wolfe |
A difficult but ultimately fairly successful day of vent recovery. We ended up with five plasmas, but the last two were full length and in succession, after a day of one plasma followed by of order 10 fizzles and duds. Plasmas were #2 : 600kA, .29sec #11: 700kA, .45sec #20: 700kA, 1.4sec #32: 800kA, 2.0sec #33: 900kA, 1.8sec (with up to 1.7MW of RF and a short H-mode) The H/D on the successful plasmas was remarkably low, down to 6% on 20, and around 8-10% on the later shots. Shot #32 had very little fueling, and the density was actually falling after 1sec. Shot #33 had some fueling, but I think it may have been coming from the RF. For most of the day the wall/dust pumping was extremely fast. We tried ECDC between shots 7 and 8, and the base pressure dropped back to 1e-6 by the time we could get the next shot set up. Most of the day the base pressure was below 5e-7. I spent a lot of time chasing the pressure around to get out of dudland and fizzledom, with no real success. I also made very small tweaks to the fields, ending up with Br0=-.0005 (started at -.0007, at one point was as high as -.0002) and IC_EF4U at -1340 (started at -1325). There were some late breakdowns which may have been helped by the field tweaks. Or not. Data system ran fine all day (no hangs). Cameras got off to a bad start, but Jim managed to get them sort of working. Wide1 and JANT views had a trigger timing problem almost all day, so the plasmas seem to start around 0.4sec. LH view, once it started working, had the correct timing. This is especially mysterious since they are all on the same trigger. |
| Session Leader Comments | |||
| May 19 2005 09:44:27:310AM | 1050519002 | Jim Irby | H/(H+D) at 14%
lots of UFOs on wide 1. |
| May 19 2005 10:03:59:440AM | 1050519004 | Jim Irby | fizzle
some problems with cameras |
| Physics Operator Comments | |||
| May 19 2005 07:43:40:137AM | Steve Wolfe |
Load from 1050506032
Note that active segment is 3.
Note that in seg3, nl04=5e19, goes negative after 1sec
pg3has a 60V puff between .7 and 1sec
** Eliminate this puff **
Import seg3 (fiducial) from 1050429001 into seg2; leave off
Note in seg1: Br0=-0.0007 T
IC_EF4U=-1325 A
RCUR offset=2500 A-m
pg4=33 msec
Load at 19-May-2005 07:43:14.00
Open tree /home/wolfe/pcs_scratch -1
Open tree done
| |
| May 19 2005 09:18:12:333AM | 1050519001 | Steve Wolfe | Shot#1: p0 in INIT 1.4e-7 fizzle. CIII signal looks high, probably too much gas. pressure is over .045mTorr EF1L current waveform is delayed rise, gets there in the end. We've seen that before; Gary says the fix is to reset a pot in the control cabinet hardly any current rise. Next shot: reduce pg4 to 25ms |
| May 19 2005 09:40:27:043AM | 1050519002 | Steve Wolfe | Shot#2: reduce pg4 to 25ms short plasma to .285sec, current turns around earlier H/D is .14, zave is 3-4. Injection at .216sec next shot: repeat |
| May 19 2005 09:45:15:823AM | 1050519003 | Steve Wolfe | Shot#3:repeat dud? gas may now be low? Br0 is low. next shot: pg4 to 28ms, br0 to -.0005 |
| May 19 2005 10:00:53:113AM | 1050519004 | Steve Wolfe | Shot#4: pg4 from 25->28ms, br0 from -.0007 to -.0005 fizzle, late breakdown 10ms, no CIII signal at all next shot: pg4 to 30ms, ef4 to -1335 |
| May 19 2005 10:16:58:373AM | 1050519005 | Steve Wolfe | Shot#5:pg4 to 30ms, ef4 to -1335 dud. Pressure is up to .045, Br and Bz look good Nothing obvious on the rga. Base is down to 2.8e-7Torr next shot: raise fill again? |
| May 19 2005 10:43:35:690AM | 1050519006 | Steve Wolfe | Shot#6:pg4 back to 33ms; if this is a dud, reload shot 2 Dud. Reload shot 2. If that's a dud, ecdc |
| May 19 2005 11:00:32:823AM | 1050519007 | Steve Wolfe | Shot#7: Reload shot 2. If that's a dud, ecdc Dud. Try 15 minutes of ecdc in D2, 2e-4Torr |
| May 19 2005 11:32:56:917AM | 1050519008 | Steve Wolfe | Shot#8: Repeat shot 2 after 15minutes ecdc Base pressure drops to below 2e-6 almost immediately after turning off ecdc. Down to 1.0e-6 in check! fizzle. Breakdown time and levels look ok, except the CIII signal is non-existent. No current takeoff at all. p0 starts around .04mTorr and rises to .055. Br0 still looks too negative to me, around -1mT. RGA shows a lot of diborane residue pumping away (on the 10^-9 scale). Next shot: repeat and see how the gas situation evolves, even though I expect another dud. |
| May 19 2005 11:39:51:963AM | 1050519009 | Steve Wolfe | Shot#9: repeat and see how the gas situation evolves, even though I expect another dud. base pressure is now down to 4e-7 again. fizzle. Late breakdown (10ms), CIII signal is back Still no current rise. next shot: raise br0 by .5mT |
| May 19 2005 11:53:04:760AM | 1050519010 | Steve Wolfe | Shot#10: raise br0 from -.0007 to -.0002 Fizzle. Still a late breakdown, around 8.5msec More CIII, a little bit of gas current. next shot: ef4 to -1340 |
| May 19 2005 12:12:34:757PM | 1050519011 | Steve Wolfe | Shot#11: ef4 to -1340; base pressure down to 2.5e-7 short plasma to .44sec. Rising density after .3sec, then a shark fin(?) or Marfe. breakdown is back at ~5msec. OH1 crowbarred after the disruption H/D under 0.1. Lots of dust on JANT and LH views. Note that Wide1 and JANT still have a trigger timing issue next shot: I should adjust the gas, but since I'm not sure which way to go, I'll leave it alone. |
| May 19 2005 12:28:40:737PM | 1050519012 | Steve Wolfe | Shot#12: repeat. dud. Base pressure was 4e-7 or so, I think. Just repeat one more time, then do something |
| May 19 2005 12:39:47:223PM | 1050519013 | Steve Wolfe | Shot#13: repeat. Another dud. Next shot: drop the gas a little (?!) |
| May 19 2005 12:51:26:757PM | 1050519014 | Steve Wolfe | Shot#14: pg4 from 25 to 23msec (I know, normally would go the other way; try this anyhow). Base pressure is now 2.7e-7 Another dud. Ok, try raising the gas. |
| May 19 2005 01:04:52:630PM | 1050519015 | Steve Wolfe | Shot#15: pg4 to 30ms 2.2e-7 in check. dud. Try even more gas |
| May 19 2005 01:22:03:030PM | 1050519016 | Steve Wolfe | Shot#16: pg4 to 35ms fizzle. Breakdown slightly late, around 7ms pressure at bd ~.055mTorr; hardly any current, again no CIII light, but plenty of Zmeter and Dalpha. This may be trying to tell me something about where the breakdown is happening. Br0 seems to be drifting up a little. Resist the urge to lower it again. next shot: repeat |
| May 19 2005 01:31:01:573PM | 1050519017 | Steve Wolfe | Shot#17: repeat, see if it gets better or worse left to itself. fizzle. Almost identical. next shot: Still more gas, since it seemed to help? |
| May 19 2005 01:45:24:277PM | 1050519018 | Steve Wolfe | Shot#18: Pg4 to 38msec. I thinks that's the highest I've ever run it. Fizzle. Looks the same. Bd around 6msec. Next shot: Back to 30msec on pg4, see if it takes off or duds out. |
| May 19 2005 01:58:30:933PM | 1050519019 | Steve Wolfe | Shot#19: Pg4 to 30msec, as if it matters what I do. Fizzle, got a little gas current this time. More CIII light too. Shot 15 was a dud with this gas puff. OK, drop the gas some more. |
| May 19 2005 02:11:31:480PM | 1050519020 | Steve Wolfe | Shot#20: Pg4 to 27msec Plasma to 1.4sec, almost made it to rampdown. I claim it's because Yijun lost faith and shut off the RF! Density still rising throughout the shot, reaches 1.36e20 before the final fin. breakdown was earlier, around 5ms again. next shot: Raise Ip to 800kA in seg3 (why not?) |
| May 19 2005 02:21:58:060PM | 1050519021 | Steve Wolfe | Shot#21: Ip to 800kA, leave startup alone It'll probably take another 9 shots to get another one to go anyway. fizzle. At least it wasn't a dud. Got a little current too. Next shot: repeat. |
| May 19 2005 02:36:59:803PM | 1050519022 | Steve Wolfe | Shot#22: repeat That one was a dud though. Oh well! Just run them off, it will go when it's ready. |
| May 19 2005 02:47:51:977PM | 1050519023 | Steve Wolfe | Shot#23: repeat And a repeat dud! Why did 21 flash? Why ask why? Let's get crazy: puff some argon |
| May 19 2005 03:00:59:990PM | 1050519024 | Steve Wolfe | Shot#24: put in 50ms of argon at -0.5sec Still a dud, it didn't help; can't see the difference on the ratiomatic either. Next shot: raise the fill again |
| May 19 2005 03:12:14:020PM | 1050519025 | Steve Wolfe | Shot#25:pg4 back to 30ms, argon off in seg1 fizzle. We've been here before. breakdown at 5.9ms, no current rise to speak of. next: repeat, see if it gets better. When it doesn't, drop the gas back down |
| May 19 2005 03:23:38:280PM | 1050519026 | Steve Wolfe | Shot#26:repeat another dud. Ok, raise it some more, then come down. |
| May 19 2005 03:37:02:353PM | 1050519027 | Steve Wolfe | Shot#27: pg4 to 33msec fizzle, maybe a little gas current. one more like this, then drop the fill |
| May 19 2005 03:49:00:653PM | 1050519028 | Steve Wolfe | Shot#28:repeat fizzle. A little better next: drop pg4 1ms |
| May 19 2005 04:03:03:223PM | 1050519029 | Steve Wolfe | Shot#29: pg4 to 32msec fizzle, late breakdown~9msec but more current pg4 to 31msec |
| May 19 2005 04:14:41:913PM | 1050519030 | Steve Wolfe | Shot#30: pg4 to 31msec fizzle. Breakdown has definitely gotten later br0 to -.0005 |
| May 19 2005 04:27:31:140PM | 1050519031 | Steve Wolfe | Shot#31: br0 to -.0005 from -.0002 fizzle. Stronger, almost made it; bd earlier too. next shot: drop pg4 back to 30ms |
| May 19 2005 04:46:53:613PM | 1050519032 | Steve Wolfe | Shot#32: drop pg4 back to 30ms from 31 plasma full length at 800kA density actually falls, from a max value of .66e20 H/D ~0.08; not bad for this density. next shot: raise Ip to 900kA |
| May 19 2005 04:56:26:773PM | 1050519033 | Steve Wolfe | Shot#33:raise Ip to 900kA plasma to 1.8sec. Density rises some that time. Rf from E and J quick h-mode at 0.87sec next shot: go for 1MA (why not?) |
| May 19 2005 05:05:22:763PM | 1050519034 | Steve Wolfe | Shot#34:raise Ip to 1MA fizzle. That's all for today. |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 09:09:32:730AM | Plasma | Ok | |
| 2 | 09:28:36:377AM | Plasma | Ok | |
| 3 | 09:42:02:370AM | Plasma | Ok | |
| 4 | 09:55:06:430AM | Plasma | Ok | |
| 5 | 10:08:05:253AM | Plasma | Ok | |
| 6 | 10:42:05:833AM | Plasma | Ok | |
| 7 | 10:57:52:540AM | Plasma | Ok | |
| 8 | 11:24:14:990AM | Plasma | Ok | |
| 9 | 11:36:46:387AM | Plasma | Ok | |
| 10 | 11:49:24:407AM | Plasma | Ok | |
| 11 | 12:02:13:537PM | Plasma | Ok | |
| 12 | 12:24:06:053PM | Plasma | Ok | |
| 13 | 12:36:41:447PM | Plasma | Ok | |
| 14 | 12:49:23:260PM | Plasma | Ok | |
| 15 | 01:02:05:900PM | Plasma | Ok | |
| 16 | 01:15:34:270PM | Plasma | Ok | |
| 17 | 01:28:25:790PM | Plasma | Ok | |
| 18 | 01:40:59:773PM | Plasma | Ok | |
| 19 | 01:53:39:833PM | Plasma | Ok | |
| 20 | 02:06:19:177PM | Plasma | Ok | |
| 21 | 02:19:04:157PM | Plasma | Ok | |
| 22 | 02:31:32:913PM | Plasma | Ok | |
| 23 | 02:44:03:773PM | Plasma | Ok | |
| 24 | 02:56:39:553PM | Plasma | Ok | |
| 25 | 03:09:12:070PM | Plasma | Ok | |
| 26 | 03:21:54:540PM | Plasma | Ok | |
| 27 | 03:34:24:413PM | Plasma | Ok | |
| 28 | 03:46:59:827PM | Plasma | Ok | |
| 29 | 03:59:38:550PM | Plasma | Ok | |
| 30 | 04:12:10:727PM | Plasma | Ok | |
| 31 | 04:24:53:590PM | Plasma | Ok | |
| 32 | 04:38:07:313PM | Plasma | Ok | |
| 33 | 04:50:38:680PM | Plasma | Ok | |
| 34 | 05:03:42:260PM | Plasma | Ok | |