| Miniproposals | ||||||||||
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| Operators | |
| Session leader(s): | Kirill Zhurovich |
| Physics operator(s): | Jim Irby |
| Engineering operator(s): | Bill Cochran,Sam Pierson,Bill Parkin |
| Engineering Operator Run Comment |
| MP#422 |
| Session Leader Plans |
| Entered: Jul 6 2005 01:36:56:893PM |
| Author: Kirill Zhurovich |
| MP#422 -- "ITB formation -- Ti critical gradient dependence"
The purpose of this experiment is to understand triggering mechanism for producing off-axis ICRF internal transport barriers. The question of whether ITB formation can be explained in the framework of suppressing ITG turbulence via increasing ion temperature scale length to the critical scale length is the target. This idea will be tested by varying Bt and thus shifting the RF resonance location on shot-to-shot basis. Required diagnostics: all standard core diagnostics, especially TS, ECE, HIREX, PCI +CHERS (if available) Set up GPC for 5.4T (or higher) and GPC2 for 6.2T operation. ICRF - 80MHz, 3MW (or less, but fault-free and constant for all discharges). ICRF power will be adjusted during first plasma shots. Proposed Bt, Ip scan: Bt Ip 5.4 0.9 5.5 0.917 5.6 0.933 5.7 0.95 5.8 0.967 5.9 0.983 6.0 1.0 6.1 1.017 6.2 1.033 6.3 1.05 6.4 1.067 6.45 1.075 First, establish an ITB at higher field. 1040310012 is a good candidate (just change a current a bit). Then start Bt scan with 0.2T increment, filling the gaps later in the day as time allows. Last time we did this experiment we were struggling with the radiation. This time we might want between shots boronization. - |
| Physics Operators Plans |
| Entered: Jul 7 2005 07:25:12:210AM |
| Author: Jim Irby |
| Run Plan for Thursday, July 7, 2005
MP#422 ITB Formation SL: Kirill Zhurovic PO: Jim Irby Run BEGINS @ 09:00 and ENDS @ 17:00 One hour of ECDC in D2 at 2e-4 Torr before the run Power systems as on 1050701034 --- be ready for 6.5 T operation A-coil in standard configuration (+Dtop -Dbot -Jtop +Jbot) C-coil Start=0.3sec, Invert=2.0sec ICRF in Run-on condition by 8:30 AM Gas setup: fill B-top 6psi D2 Hybrid Enabled (PG4) fill B-side lower 1psi Argon Hybrid DISABLED (PG1) leave B-side Upper alone Hybrid DISABLED (PG2) fill B-main 40psi D2 Hybrid Enabled (PG3) Enable: ECE, VUV, Z-bolo shutter |
| Session Leader Summaries |
| Entered: Jul 7 2005 05:35:39:913PM |
| Author: Kirill Zhurovich |
| In the beginning we tried to reproduce ITBs from 1040310, which were obtained at Bt=6.45T. We were struggling with the machine operation first half of the day. Got some weak ITBs on shots 5,6.
Later Amanda and Steve Wolfe figured out that at this high field RF resonance touched J antenna. We lowered the field to shift the resonance away from the antenna a bit and starting from that point we had a successful run. Useful shots: 19,20-29 Resultant Bt, Ip scan (numbers as requested by PO): Bt Ip 6.27 1.0 6.2 0.989 6.1 0.973 6.0 0.957 5.9 0.941 5.8 0.925 5.7 0.909 5.6 0.893 5.5 0.877 5.4 0.861 Both GPC and GPC2 were working covering almost the whole profile for the entire scan. Later in the day RF was quite reliable. Overall, successful run, scan is completed. First results show sharp ITB threshold for the field, which is consistent with the data in the past. Today we had nice ITB at 6.3T, weaker for 6.2T, marginal for 6.1T, and no ITB for 6.0T. Analysis of the temperature gradient will follow. |
| Physics Operator Summaries |
| Entered: Jul 7 2005 05:54:42:617PM |
| Author: Jim Irby |
| The object of this run, from the PO point of view, was to get ITBs and
then scan the toroidal field and plasma current at constant q. We started from a good ITB shot from last year, 1040310012. During this run D- and E-Port antennas were used to supply about 3 MW of power. Because of our problem with D-Port, we used E- and J-Port for today's run. However, running at the same field of 6.45 T used last year put the 78 MHz ICRF resonance inside of the J-Port antenna (top and bottom). This error resulted in injections and certainly no ITBs (problem pointed out to PO by Amanda and Steve Wolfe on shot 18). Reducing the field produced a nice ITB on shot 19. From shot 19 onward, some very nice h-mode plasmas were produced, and the field and current scan proceeded well. We had one of the mystery h-alpha glitches at startup which resulted in a fizzle, but otherwise the machine ran very well. We did 20 minutes of boronization before shot 9, but the resonance location problem caused disruptions that probably quickly negated any positive effects. Shot 1 was a TF test at 50 kA since several fuses had been replaced. Very little tuning of the fields or pressure was required today. For shot 30 a 15 A change in ef4 brought Bz0 back in line and improved the late breakdown. |
| Session Leader Comments | |||
| Jul 7 2005 09:23:40:583AM | 1050707002 | Kirill Zhurovich | Multiple H-modes, one long one, which did not look like EDA
(though there is some indicaion of Qc mode: broad and around 250KHz) RF trips a lot No peaking |
| Jul 7 2005 09:44:08:757AM | 1050707003 | Kirill Zhurovich | 2 H-modes, second long one.
RF trip a lot during second H-mode Radiation is reasonable. No peaking |
| Jul 7 2005 10:04:01:170AM | 1050707004 | Kirill Zhurovich | 2 H-modes, second long one.
RF is 2.5MW, no trips Looks like weak ITB for ~ 1.35-1.5s |
| Jul 7 2005 10:17:42:210AM | 1050707005 | Kirill Zhurovich | multiple H-modes, last one is longer (more ELM-free)
RF trips a lot during last H-mode Looks like no peaking |
| Jul 7 2005 10:29:42:540AM | 1050707006 | Kirill Zhurovich | 2 H-modes, last one is long.
RF trips a lot during last H-mode But there is an ITB starting at ~ 1.15s |
| Jul 7 2005 10:56:24:227AM | 1050707007 | Kirill Zhurovich | Disruption at ~0.75 s (H-mode phase) |
| Jul 7 2005 11:16:36:947AM | 1050707008 | Kirill Zhurovich | Multiple H-modes
RF is relatively clean at 2.5MW Radiation killed all H-modes Next: boronize for 20min |
| Jul 7 2005 11:58:17:587AM | 1050707009 | Kirill Zhurovich | No plasma as expected |
| Jul 7 2005 12:10:46:150PM | 1050707010 | Kirill Zhurovich | Disruption at ~0.77s |
| Jul 7 2005 12:28:44:727PM | 1050707011 | Kirill Zhurovich | 3 H-modes, again killed by big injections
RF trips |
| Jul 7 2005 12:43:58:257PM | 1050707012 | Kirill Zhurovich | Fizzle |
| Jul 7 2005 12:59:43:100PM | 1050707013 | Kirill Zhurovich | Disruption at ~0.77s |
| Jul 7 2005 01:11:47:867PM | 1050707014 | Kirill Zhurovich | 4 H-modes
RF is relatively clean at 2.6MW Radiation is back - injections up to 2MW |
| Jul 7 2005 01:39:32:353PM | 1050707015 | Kirill Zhurovich | L-mode
we raised the target density for this shot and apparantly reached H-mode threshold RF was relatively clean at 2.5MW until ~1.28s Next: decrease the target desnity a bit |
| Jul 7 2005 01:54:51:883PM | 1050707016 | Kirill Zhurovich | 2 brief H-modes
RF is relatively clean, but it seems that we are right on the H-mode threshold: 2.5MW --> no H-mode, 2.7MW --> L-H transition Next: 1)decrease the target density a bit more to get H-mode, 2) decrease Ip to 1MA to make H-mode more EDAish |
| Jul 7 2005 01:57:55:240PM | 1050707017 | Kirill Zhurovich | No plasma |
| Jul 7 2005 02:20:16:510PM | 1050707018 | Kirill Zhurovich | L-mode
It turns out that the RF resonance is inside J antenna right now. Next: decrease Bt to shift the resonance inside the plasma |
| Jul 7 2005 02:36:17:477PM | 1050707019 | Kirill Zhurovich | Nice ITB starting at ~1.15s
RF is clean at 2.8MW Bt=6.28T, Ip=1MA q95=4.6 Next: decrease Bt by 0.2T and current proportionally |
| Jul 7 2005 02:54:30:570PM | 1050707020 | Kirill Zhurovich | No plasma
Next: Bt=6.1T and Ip=0.973MA |
| Jul 7 2005 03:14:19:790PM | 1050707021 | Kirill Zhurovich | Nice steady H-mode, possibly with weak ITB
RF is steady at 2.8MW Bt=6.13T, Ip=0.973MA, q95=4.6 Next: Bt=5.9T and Ip=0.941MA |
| Jul 7 2005 03:37:12:913PM | 1050707022 | Kirill Zhurovich | 2 H-modes, first one is longer
1 RF trip Bt=5.93T, Ip=0.943MA, q95=4.5 Next: Bt=5.7T and Ip=0.909MA |
| Jul 7 2005 03:37:00:460PM | 1050707023 | Kirill Zhurovich | nice long H-mode
2 RF trips at the beginning of H-mode Bt=5.74T, Ip=0.91MA, q95=4.5 Next: Bt=5.5T and Ip=0.877MA |
| Jul 7 2005 03:47:14:570PM | 1050707024 | Kirill Zhurovich | nice long H-mode
1 RF trip, 2.75MW Bt=5.55T, Ip=0.88MA, q95=4.5 Next: Bt=6.2T, Ip=0.989MA |
| Jul 7 2005 04:03:46:227PM | 1050707025 | Kirill Zhurovich | definitely an ITB, starting at around 1.12s
RF is clean at 2.75MW Bt=6.22T, Ip=0.984MA, q95=4.55 Next: Bt=6.0T, Ip=0.957MA |
| Jul 7 2005 04:16:02:727PM | 1050707026 | Kirill Zhurovich | nice long H-mode
RF is clean at 2.8MW Bt=6.02T, Ip=0.955MA, q95=4.5 Next: Bt=5.8T, Ip=0.925MA |
| Jul 7 2005 04:32:11:477PM | 1050707027 | Kirill Zhurovich | nice long H-mode
RF is clean at 2.75MW Bt=5.83T, Ip=0.927MA, q95=4.5 Next: Bt=5.6T, Ip=0.893MA |
| Jul 7 2005 04:43:47:100PM | 1050707028 | Kirill Zhurovich | nice long H-mode
RF is clean at 2.8MW Bt=5.64T, Ip=0.894MA, q95=4.5 Next: Bt=5.4T, Ip=0.861MA |
| Jul 7 2005 04:58:23:290PM | 1050707029 | Kirill Zhurovich | nice long H-mode
RF is clean at 2.8MW Bt=5.45T, Ip=0.862MA, q95=4.5 We completed the scan! Next: Bt=6.24T, Ip=0.995MA - ITB attempt |
| Jul 7 2005 05:08:57:353PM | 1050707030 | Kirill Zhurovich | L-mode
end of run |
| Physics Operator Comments | |||
| Jul 7 2005 09:07:48:540AM | 1050707001 | Jim Irby | loaded shot from 1040310012 --- a good ITB shot
zeroed offset in clearin --- also did an unnecessary call zeroed offset in IP --- did a call TF current limit at 180 kA so we can get our 6.45 T loaded seg 1 from 1050705022 into seg 1 prefill set to 16 ms did a load/clean both Bt and Ip came up faster in 1040310 than in last week's ITB attempt (1050701) In 1040310 ICRF was provided by D- and E-Port antennas not J-Port. Last week the ICRF was ramped up rather than banged on. There were also 1/2 cm or more differences in gaps. H/(H+D) was similar as was the radiated power. 1040310 was several run days after a boronization. Radiation was lower during yesterday's run than during the 1040310 run. Several fuses were replaced in the TF this morning. First shot will be a 50 kA test of the TF supply. Should have gas TF looks good to me Gas pretty low --- will up for next shot |
| Jul 7 2005 09:30:18:007AM | 1050707002 | Jim Irby | prefill from 16 to 18 ms for this shot
plasma into rampdown startup fields good, but gas looks very low --- almost lost it around 14 ms bunch of early injections Bt was low? Outer gap a little to small for RF guys radiated power high early |
| Jul 7 2005 09:48:35:490AM | 1050707003 | Jim Irby | rcur reduced from 0.664 to 0.662 m
TF current request to 178.385 kA prefill from 18 to 19 ms plasma into rampdown -- several h-modes startup a little better outer gap much better several early injections did us in again |
| Jul 7 2005 10:04:32:200AM | 1050707004 | Jim Irby | rcur from 0.662 to 0.661 m
plasma into rampdown --- multiple h-modes again injection at 0.77 s did in h-mode RF power very clean but also a little lower at 2.48 MW RF group happy with gaps stored energy is higher with less power than on 1040310012 |
| Jul 7 2005 10:27:30:133AM | 1050707005 | Jim Irby | TF current to 179 kA
Target density to 1.2 from 1.1e20 /m^2 plasma into rampdown --- multiple h-modes got higher target density still large injections |
| Jul 7 2005 10:49:19:820AM | 1050707006 | Jim Irby | repeat with a little less power (2.5 MW)
plasma into rampdown --- 2 h-modes, second one extended weak ITB seen large injection does in first h-mode |
| Jul 7 2005 11:01:58:367AM | 1050707007 | Jim Irby | delay to setup for between shot boronization --- but will take a couple of more shots before we do it
TF current from 179 to 181 kA disruption at .748 s, big injection Bt to 6.46 T, not bad |
| Jul 7 2005 11:16:29:400AM | 1050707008 | Jim Irby | prefill reduced from 19 to 18 ms
plasma into rampdown --- several h-modes 2Pi radiation/injections John sees moly up |
| Jul 7 2005 12:03:54:117PM | 1050707009 | Jim Irby | stopped to do 20 minues of boronization before this shot --- 50/52/103 cm
diborne request 56 mTorr for first 15 minutes then 66 mTorr for last 5 minutes prefill from 18 to 13 ms 3.5e-6 Torr entering INIT fizzle --- as expected CIII signal zeroed again |
| Jul 7 2005 12:23:19:273PM | 1050707010 | Jim Irby | prefill from 13 to 16 ms
disruption at 0.77 s: injection after rf moly way down at least early in the shot still see early injections on 2Pi prad very low early |
| Jul 7 2005 12:38:34:807PM | 1050707011 | Jim Irby | left prefill at 16 ms
plasma into rampdown --- 2 h-modes will add a-coils next shot --- may have had locked mode |
| Jul 7 2005 12:46:10:617PM | 1050707012 | Jim Irby | a-coils programmed to ramp up to 1000A from .3 to .45 s and then to 2500A from .45 to 1.5 s.
fizzle --- several bounces fields good --- pressure low |
| Jul 7 2005 01:03:04:040PM | 1050707013 | Jim Irby | prefill from 16 to 18 ms
disruption at 0.77 s again! next shot we move out of the slot |
| Jul 7 2005 01:18:27:227PM | 1050707014 | Jim Irby | RXL from -0.01 to 0.00
plasma into rampdown, but four h-modes |
| Jul 7 2005 01:45:48:320PM | 1050707016 | Jim Irby | density request from 1.2 to 1.35e20 /m^2
neon puff from bside-upper from 1.4 to 1.44 s (voltage setting was too low) plasma into rampdown, but no h-modes (density too high, pressure too high) |
| Jul 7 2005 01:52:23:040PM | 1050707016 | Jim Irby | density request to 1.2e20/m^2
plasma into rampdown --- very late h-mode |
| Jul 7 2005 02:09:58:350PM | 1050707017 | Jim Irby | density request to 1.1e20/m^2
Ip request to 1.0 MA fizzle --- doubling of h-alpha signal at 10 ms as seen yesterday |
| Jul 7 2005 02:21:45:493PM | 1050707018 | Jim Irby | no DCPS changes
l-mode plasma into rampdown Amanda and Steve Wolfe point out the resonance is at the top of the j-port antenna |
| Jul 7 2005 02:51:24:633PM | 1050707020 | Jim Irby | TF from 175.4 to 169.7 kA
Didn't drop Ip as asked for by SL dud --- |
| Jul 7 2005 03:13:00:163PM | 1050707021 | Jim Irby | argon enabled
Bt to 6.1T, 170.913 kA Ip to 0.973 MA prefill from 18 to 20 ms plasma into rampdown --- very nice extended h-mode |
| Jul 7 2005 03:24:10:867PM | 1050707022 | Jim Irby | Bt to 5.9 T at 165.3 kA
Ip to 0.941 MA prefill to 21 ms plasma into rampdown two h-modes |
| Jul 7 2005 03:38:25:383PM | 1050707023 | Jim Irby | Bt to 5.7 T
Ip to 0.909 MA plasma into rampdown nice h-mode |
| Jul 7 2005 03:47:32:523PM | 1050707024 | Jim Irby | Bt to 5.5 T
Ip to 0.877 MA plasma into rampdown nice long h-mode |
| Jul 7 2005 04:04:43:757PM | 1050707025 | Jim Irby | Bt 6.2 T
Ip 0.989 MA plasma into rampdown ITB looks good |
| Jul 7 2005 04:14:06:820PM | 1050707026 | Jim Irby | neon puff from 1.0 to 1.040 s (was at 1.4 s)
Bt to 6.0 T Ip to 0.957 MA plasma into rampdown |
| Jul 7 2005 04:33:41:180PM | 1050707027 | Jim Irby | Bt to 5.8 T
Ip to 0.925 MA neon at 0.3 s for 40 ms nice h-mode |
| Jul 7 2005 04:43:58:257PM | 1050707028 | Jim Irby | Bt to 5.6 T
Ip to 0.893 MA plasma into rampdown good extended h-mode |
| Jul 7 2005 04:59:36:587PM | 1050707029 | Jim Irby | Bt to 5.4 T
Ip to 0.861 MA Added 1 ms to prefill nice long h-mode |
| Jul 7 2005 05:21:08:727PM | 1050707030 | Jim Irby | ef4 to -1325 from -1310 A
Bt to 6.24 T Ip to 0.995 MA plasma into rampdown l-mode?? had rf, current, and field |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 09:02:33:350AM | Test | Ok | TF 50kA PLC test shot |
| 2 | 09:15:10:443AM | Plasma | Ok | |
| 3 | 09:36:30:507AM | Plasma | Ok | |
| 4 | 09:53:58:813AM | Plasma | Ok | |
| 5 | 10:08:48:947AM | Plasma | Ok | |
| 6 | 10:23:05:650AM | Plasma | Ok | |
| 7 | 10:53:38:680AM | Plasma | Ok | |
| 8 | 11:06:29:913AM | Plasma | Ok | |
| 9 | 11:55:47:523AM | Plasma | Ok | |
| 10 | 12:08:28:867PM | Plasma | Ok | |
| 11 | 12:22:03:100PM | Plasma | Ok | |
| 12 | 12:39:46:900PM | Plasma | Ok | |
| 13 | 12:52:15:570PM | Plasma | Ok | |
| 14 | 01:05:15:320PM | Plasma | Ok | |
| 15 | 01:27:39:947PM | Plasma | Ok | |
| 16 | 01:40:36:367PM | Plasma | Ok | |
| 17 | 01:55:03:210PM | Plasma | Ok | |
| 18 | 02:08:04:773PM | Plasma | Ok | |
| 19 | 02:23:05:383PM | Plasma | Ok | |
| 20 | 02:42:05:850PM | Plasma | Ok | |
| 21 | 02:58:31:913PM | Plasma | Ok | |
| 22 | 03:16:59:257PM | Plasma | Ok | |
| 23 | 03:29:34:447PM | Plasma | Ok | |
| 24 | 03:42:18:697PM | Plasma | Ok | |
| 25 | 03:54:49:180PM | Plasma | Ok | |
| 26 | 04:08:31:663PM | Plasma | Ok | |
| 27 | 04:27:04:150PM | Plasma | Ok | |
| 28 | 04:39:52:227PM | Plasma | Ok | |
| 29 | 04:52:13:523PM | Plasma | Ok | |
| 30 | 05:05:51:913PM | Plasma | Ok | |