| Miniproposals | ||||||||||
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| Operators | |
| Session leader(s): | Steve Wukitch |
| Physics operator(s): | Steve Wolfe |
| Engineering operator(s): | Ed Fitzgerald,Bill Cochran |
| Engineering Operator Run Comment |
| MP#355: Make the RF work at 50MHz; MP#370: Large Volume ITB at 2.8 T; Sl |
| Session Leader Plans |
| Physics Operators Plans |
| Session Leader Summaries |
| Entered: Jul 7 2004 03:49:03:257PM |
| Author: Steve Wukitch |
| Run Plan and Engineering Setup for Tues. 2-Mar-2004 MP#355: Make the RF work at 50MHz SL: Wukitch FOLLOWED AS QUICKLY AS POSSIBLE BY MP#370: Large Volume ITB at 2.8 T SL: Rice PO: wolfe Engineering setup: ------------------ ECDC overnight in D2, stopping by 07:00 Run begins at 09:00, ends at 17:00 Power supplies as on 1040301018 Gas System 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 with 15 psi He3 Hybrid DISABLED (PG2) fill C-side with 30 psi D2 Hybrid enabled (PG3) fill NINJA (lower cap) with 5 psi D2 Run Plan: --------- Spend as much time as required getting the RF working at 50MHz, using central H minority at B=3.5 T, as on 1040301. Pick a shot based on whether Irby has the TCI working again, then tweak as requested by SL (Wukitch); most likely we'll continue with inner wall limiter discharges. Once we get up to a reliable 2MW, change over to the ITB experiment. For MP#370, change to LSN equilibrium at 2.8T, 500kA, nl04=0.9e20 and try for an EDA H-mode and subsequent ITB. RF should program for 0.5sec, 2MW pulse from J during TF flattop (probably starting at t~1sec ). If we get an ITB, take 5 shots to get good density profiles, and an additional 5-10 shots to investigate on-axis heating with D&E (2nd harmonic at 80MHz). If no ITB at first, try adjusting the density to improve the EDA character, and perhaps scan the field. ********************************************************************** 001 cycle test 002 early disruption 003 BT~3.3 T, Ip~0.8 MA, nl_04~0.8, no He, IW limited J3: 0.3-0.5 MW [1.25,1.5]sec J4: 0.3-0.5 MW [1.,1.25]sec result: plasma - early disruption J3: max faults J4: ran both the glow paddles and the MHD antenna have been disconnected and shielded during the overnight interference is still present 004 BT~3.3 T, Ip~0.8 MA, nl_04~0.8, no He, IW limited J3: 0.3-0.5 MW [1.,1.25]sec J4: 0.3-0.5 MW [1.25,1.5]sec result: plasma - early disruption J3: J4: ran J3 forward calibration appears to be incorrect J3 reflected appears to be too small by ~ a factor of 2 END of RUN Run Summary The RF interference is the highest since the incident where the coax was left open, so the run was terminated to investigate. Using the Kalmus source (<500 W), the DC breaks were found to be radiating quite severely. |
| Physics Operator Summaries |
| Entered: Jul 7 2004 04:36:49:067PM |
| Author: Steve Wolfe |
| Physics Operator Summary for Tuesday, Mar 2, 2004 MP#355 RF commissionin (50 MHz) SL: Wukitch FOLLOWED AS QUICKLY AS POSSIBLE BY MP#370: Large Volume ITB at 2.8 T SL: Rice PO: wolfe EO: Cochran, Fitzgerald Engineering setup: ------------------ ECDC overnight in D2, stopping by 07:00 Run begins at 09:00, ends at 17:00 Power supplies as on 1040301018 Gas System 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 with 15 psi He3 Hybrid DISABLED (PG2) fill C-side with 30 psi D2 Hybrid enabled (PG3) fill NINJA (lower cap) with 5 psi D2 Run Plan: --------- Spend as much time as required getting the RF working at 50MHz, using central H minority at B=3.5 T, as on 1040301. Pick a shot based on whether Irby has the TCI working again, then tweak as requested by SL (Wukitch); most likely we'll continue with inner wall limiter discharges. Once we get up to a reliable 2MW, change over to the ITB experiment. For MP#370, change to LSN equilibrium at 2.8T, 500kA, nl04=0.9e20 and try for an EDA H-mode and subsequent ITB. RF should program for 0.5sec, 2MW pulse from J during TF flattop (probably starting at t~1sec ). If we get an ITB, take 5 shots to get good density profiles, and an additional 5-10 shots to investigate on-axis heating with D&E (2nd harmonic at 80MHz). If no ITB at first, try adjusting the density to improve the EDA character, and perhaps scan the field. Results ------- Not a good day. Only 3 plasma shots and 1 data system test (successful). After the second plasma it was apparent that yesterday's pickup problems were still present with FMIT#4. The next shot demonstrated that #3 was still not putting power into plasma, although the oscillation problem seems to have been fixed; it was still faulting for unexplained reasons. We took a long delay to allow RF vacuum experiments to address both issues. These only succeeded in confusing the situation further. At about 2:00PM we abandoned the run, and RF began disassembling the FMIT#4 transmission line. Apparently there is a problem at the switch in the #4 line, although it is not clear how this could possibly be involved in any of the problems we are seeing. The pickup in vacuum was bad enough to turn off diagnostic pumps and set off I2t and oxygen alarms. As far as the plasma operation is concerned, the first shot (#2) was set up like 1040301024, except the TF was lowered to 3.3T at the request of the SL. This shot is a limiter equilibrium with pre-programmed gas. The first plasma shot of the day was a short (270msec) disruption which had significant runaways. This was fixed by increasing the gas puff in seg 1 and 2, as well as the pre-puff, and changing the current rise program in seg2. Shot#3 disrupted at 1.2sec, probably because RF interference on the magnetics caused loss of control; this shot had >.5MW of RF from FMIT#4. EFIT was unconverged for all times after the start of the RF pulse. Shot #4 ran full length; the RF had max faults with very short pulses, and there was no obvious pickup, but we might not have been able to see any for these pulses. Prior to the run, Tom and Josh swapped the names and functions of alcserv3 and alcserv4 to try to isolate the server hang problems which we've been experiencing. Since only four cycles were run, with no hangs, this test is so far inconclusive. Scorecard: ---------- Tests 1 Duds 0 Fizzles 0 Plasmas 3 (1 early disruption) ======= == Total 4 |
| Session Leader Comments | |||
| Mar 2 2004 09:45:13:460AM | 1040302001 | Steve Wukitch | 001 cycle test |
| Mar 2 2004 09:45:23:647AM | 1040302002 | Steve Wukitch | 002 early disruption |
| Mar 2 2004 10:06:44:453AM | 1040302003 | Steve Wukitch | 003 BT~3.3 T, Ip~0.8 MA, nl_04~0.8, no He, IW limited J3: 0.3-0.5 MW [1.25,1.5]sec J4: 0.3-0.5 MW [1.,1.25]sec result: plasma - early disruption J3: max faults J4: ran both the glow paddles and the MHD antenna have been disconnected and shielded during the overnight RF interference is still present |
| Physics Operator Comments | |||
| Mar 2 2004 08:13:00:977AM | Steve Wolfe | Getting a slightly late start setting up for today's run. Tom and Josh were in early and swapped name and functionality of alcserv3 and alcserv4. This is supposed to tell us if the server hangs are associated with the particular server hardware. The RF crew has been waiting around to get started on retuning FMIT#3 and finding the RF leak into the cell and/or power room; they need the computers up to do their testing. Therefore, the actual run will probably be somewhat delayed this morning. | |
| Mar 2 2004 08:29:57:223AM | Steve Wolfe | Setting up for today's run in PCS. Just load the last shot from yesterday (1040301024); note that this has pre-programmed gas puff and no nl04 feedback. I'll go back to feedback later if Irby gets tci working again. Get rid of the back porch on the TF waveform. Touch wire 12 in seg1 for timestamp. (it's ef1l so just over with wire 11) Load at 2-Mar-2004 08:29:37.00 Open tree /home/wolfe/pcs_scratch -1 Open tree done | |
| Mar 2 2004 09:13:40:093AM | Steve Wolfe | We are presently locking up. The run should start soon. Since they have been firing J into the machine, we may need to do some ecdc, but we'll give it a try without and see how it goes. | |
| Mar 2 2004 08:18:16:897AM | 1040302001 | Steve Wolfe | Shot#1: Test cycle with gas. |
| Mar 2 2004 09:48:28:250AM | 1040302002 | Steve Wolfe | Shot#2: Reduce field to 3.3T (-87200A) per request of session leader Early disruption. .27sec Looks like a big injection. Also, we were getting a lot of runaways. next shot: increase pg4 from 15ms->17ms increase seg1 pg3 from 40 to 80V increase early seg2 pg3 puff increase early current rise in seg2 |
| Mar 2 2004 10:06:27:327AM | 1040302003 | Steve Wolfe | Shot#3: increase pg4 from 15ms->17ms increase seg1 pg3 from 40 to 80V increase early seg2 pg3 puff increase early current rise in seg2 disrupts at 1.2sec, breakers pulled. Lots of pickup on the magnetics, just like yesterday. EFITs are unconverged after RF turn on. next shot: Try with J3 only |
| Mar 2 2004 10:41:38:860AM | 1040302004 | Steve Wolfe | Shot#4: Try with J3 only plasma full length. Hardly any RF, no obviois pickup. RF will do vacuum testing to try to figure out what's going on. We'll be down (no shots) for at least an hour. |
| Mar 2 2004 02:01:26:480PM | 1040302004 | Steve Wolfe | Run has been terminated to allow the RF to deassemble part of the coax. |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 08:17:36:770AM | Test | Ok | |
| 2 | 09:36:06:903AM | Plasma | Ok | |
| 3 | 09:55:33:157AM | Plasma | Ok | |
| 4 | 10:23:57:000AM | Plasma | Ok | |