| Miniproposals | ||||||||||
|
| Operators | |
| Session leader(s): | Chuck Kessel |
| Physics operator(s): | Steve Wolfe |
| Engineering operator(s): | Bill Parkin,Bill Byford |
| Engineering Operator Run Comment |
| MP #466 SL Kessel PO Wolfe EO Pierson |
| Session Leader Plans |
| Entered: Apr 11 2007 08:06:37:200AM |
| Author: Chuck Kessel |
| MP#466
AIM: Establish discharges with slower Ip ramp rates to a flattop Ip of 600 kA, ranging from 250 ms (typical) to 500, 750, and 1000 ms. The experiments will determine how low an Ip value (or how early in time) the plasma current feedback and/or PF coil pre-programming can change the Ip trajectory emerging from the breakdown/startup phase. In addition, attempts will be made to divert the plasma as early as possible in order to take advantage of lower impurity concentrations and provide for very early H-mode transitions in future heated discharges. 1) start with discharge 1050708019, which reached 320 kA at 100 ms. Adjust the 2nd segment of Ip ramp to reach 600 kA by 500 ms. (1-5 shots) 2) try to reduce the early Ip value by adjusting the crowbar timing of the OH comm resistors, OH and PF voltage pre-programming, and 1st segment of Ip ramp feedback gains. Rough target is Ip = 200 kA by 75 ms. (5-10 shots) 3) attempt early diverting by adjusting the EF1 crowbar timing and shape programming to obtain diverted plasmas by 75-150 ms. (5-10 shots) 4) using the discharge with the lowest Ip value in the early ramp, establish other Ip ramp cases at 250 ms, 750 ms, and 1000 ms. Combine this with the earliest diverting plasma if possible, or best combination of low Ip and early diverted plasma. (5 shots) |
| Physics Operators Plans |
| Entered: Apr 11 2007 03:25:53:230PM |
| Author: Steve Wolfe |
PO_PLAN for Thursday, April 12, 2007
SL: Kessel
PO: Wolfe
MP#466 "Slower Ip ramp development"
Target shot for today is 5.4T, 600kA flattop, NL04=5e19, LSN.
Argon puffing (small) permitted upon request.
RF and LH piggybacking allowed after 0.7sec.
Engineering Setup:
==================
Overnight ECDC in D2, P=2e-4 Torr, sweep: Rmin=44, Rdwell=45, Rmax=103
Run begins at 09:00 and ends at 17:00
Power Systems as on 1050708019 (*** NOTE: Non-standard Crowbar timing ***)
A-coil: +Dtop -Dbot -Jtop +Jbot
** HYBRID CONTROL ** enabled (this is different from source shot).
Note to Eng Op: We may be changing commutation resistor taps during the day.
Please have meters and wrenches close to hand.
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 as is Hybrid DISABLED (PG2)
fill B-main (C-side) with 40 psi D2 Hybrid enabled (PG3)
leave NINJA as is, disabled
Enable the following gate valves and shutters, assuming no vacuum problems:
ECE, VUV, Z-bolo shutters
Torvac setup: Pumpstack gatevalves OPEN
ICRF: Not required, allowed if ICRF Group wants. Check with ICRF for
turn on instructions.
LH: Not required, allowed if LH Group wants
Physop Plan:
------------
The run plan calls for first reproducing the relatively low early current
obtained on 1050708019, then reducing that current futther, and finally trying
for earlier diversion.
Since the experiment is based on use of the techniques applied for 1050708019,
it will not be possible to use a recent startup. Therefore, I will need to
reload the target shot and, after recalculating predictors to account for the
changed magnetics (F11 and one BP coil), probably some tuning of breakdown
fields will be needed to get a plasma. PCS_compare gives over 250 lines of
differences between this shot and a recent startup:
Initial Setup:
--------------
RCUR offset is different (was 1500, now 1800); could be part of slower ramp.
BR0 is 1mT higher (.0003 vs -.0007): probably want to change
EF2 current traces have 1ms shift at -1.518 sec, import seg touch: ignore
EF4 current was -1310, now -1335: Change
All _VOLT controller times different by order 1msec: KEEP OLD?
IP control: KEEP
KEEP all original _VOLT waveforms
Acoil: change it to B21_PROJ like modern shot (wire 9, Integrator time, V
waveform)
PG4: set to 20msec ?
PG3: KEEP
Recalculate all the magnetics predictors.
In seg2, modify Ip program to reach 600kA at 500ms.
1. Establish discharge with Ip(0.1sec)~300kA, Ip(0.5s)=600kA. [1-5 shots]
1a If problems getting breakdown or current rise, revert to recent startup and then re-do
variations applied on 1050708 and/or 1050602. [3-8 shots]
2. Try to reduce early Ip to Ip(0.075s)~200kA. Tools will be earlier OH
crowbar, adjustment of voltages (OH's, EF3), Ip feedback. Maybe try to get
a head start on step 3 (early divertor) but back off if we start getting
disruptions that might increase the fizzle rate.
If desperate, reduce OH commutation resistors. Current values are (per Cryo
screen): OH1:.033, OH2:.005 +/- .001, EF1: .07 Ohms
[5-10 shots] SL should decide when to quit on this step and go on to step 3.
3. At some point, take what we've got for early current and try to bring
divertor time earlier, aiming for 75-150msec. Tools are EF1 crowbar time,
CLEARIN, RXL, ZXL program (maybe ZCUR). If necessary, move Seg2 start
earlier than 0.1 sec. [~5 shots] (we're probably going to run out of shots
before we finish this, maybe before we start)
4. If things have gone amazingly well and there's time left, use the discharge
with the best early Ip (and divertor time if possible) and change ramp rate
to get to 600kA at [250, 750, 1000] msec.
|
| Session Leader Summaries |
| Entered: Apr 12 2007 10:09:35:903PM |
| Author: Chuck Kessel |
| Run 1070412, shots 001-022: MP #466
This run was targeting slower Ip ramp rates and early diverted plasmas to provide reference discharges for hybrid and AT scenario development. An older shot 1050708019 was used as the basis since something similar had been done there. This was obtained by breaking the early Ip ramp that emerges from breakdown at t â?? 75 ms at an Ip â?? 200 kA, and proceeding with a slower Ip ramp rate (the actual breakpoint appears to be at t â?? 40-50 ms and Ip â?? 170 kA). This was largely accomplished by shifting the OH comm crowbar timing and adjusting the Ip feedback gains and their timing, and quickly yielded the desired effect by shots 003-004. The flattop Ip was 600 kA for all shots, and for most of the shots 001-016 the Ip flattop began at 500 ms. By shot 005 the EF1 crowbar was already being adjusted to earlier times to help smooth the Ip ramp and begin the earlier divert. Runaways were present on virtually all shots, in nearly all cases at an early time of 50 ms, and on many cases a long lived phase stretching from 0.1 to 0.4 s. Work continued with earlier EF1 crowbar times, CLEARMIN request and its timing, ZXU/RXU/ZXL/RXL requests and their timing, and ZCUR request and timing. The high li values obtained, 2.0-2.5, in these ohmic heated slow Ip ramp discharges were aggravating the shaping and diverting control. Ultimately, the divert time was moved back from 500 ms to 220 ms, with Ip = 315 kA and li = 2.1 (016). Then a lower Ip ramp rate was examined (017-022), making Ip start its flattop at 1000 ms. Against our intuition, these discharges had early diverting ( at 180 ms) right away, but had runaways and high densities. This was removed by using a tri-linear Ip ramp; Ip to 170 kA at 50 ms, Ip to 400 kA at 250 ms, and then Ip to 600 kA at 1000 ms. Further adjustments of CLEARMIN, ZCUR, ZXL, and RXL feedback parameters got very good inboard gap sustainment with a divert time of 180 ms. It was noticed (near the end of the run day) that the X-pt is close to the outboard shelf when the plasma goes diverted, and may provide a useful knob in future discharge to divert even earlier by making RXL smaller with earlier feedback control. Overall the run day was successful, 2 slower Ip ramp cases were established, and the divert time was made about 200 ms at low current and high li. The fact that the slower Ip ramp case diverted early right away indicates that the crowbar timing and feedback settings are robust for other Ip ramp rates. The runaways were a persistent problem, probably influencing the current profile and other discharge features, but the discharges were successful in spite of them. These discharges will be combined with early heating and current drive experiments planned in the Advanced Tokamak scenario development later this year. |
| Physics Operator Summaries |
| Entered: Apr 12 2007 06:49:31:860PM |
| Author: Steve Wolfe |
Session Leader summary for Thursday, April 12 MP#466 Slower Ip ramp development SL: Kessel PO: wolfe EO: Pierson,Parkin,Byford The aim was to develop a (post breakdown) start-up sequence with low initial current, slow current rise capability, and early diversion. We pretty much accomplished all of these, although we didn't quite get it to divert as early as requested. The starting point was 1050708019, which had a seg2 transition current around 320kA, using oh crowbar at 0.06sec and reduced OH and EF voltages in seg1. This shot had a later current ramp to high current, which we replaced with a slow ramp to 600kA at .5sec, followed by flattop at 0.6. Program density was nl04=0.5e20 all day. This discharge was satisfactorily established in one shot, although shot#1 was slightly confused by the fact that the LH accidentally fired at 0.1 sec instead of 0.7sec, resulting in lots of runaways. Step 2 of the program, reduction of the early current to 200kA at 75ms, was accomplished fairly quickly, contrary to my expectations. The key was simply moving the OH crowbar time earlier, to .04sec, and adjusting the target Ip value at 0.1sec. Dropping the OH1_VOLT pre-program voltage and EF3_VOLT and EF1_VOLT values before 50ms was also helpful. By shot#4 we declared Step 2 complete, and moved on to step 2, getting the divertor to come in earlier. For these low current conditions, the nominal programming was giving a late divertor time, around 0.5sec. This was at least partially due to high li (~2 to 2.5) in these discharges. It should be noted that we were plagued with runaways on most shots all day long. There were a few purely thermal cases, but avoiding the runaways remains an unsolved problem with this scenario. Getting the plasma to divert earlier proved much harder than I expected, and we spent much of the day on this problem. There were no serious problems moving the EF1 crowbar time earlier than the nominal .2sec, first to 0.12 and finally to 0.09. However, despite increasing the CLEARIN target significantly, we were unable to get these high li discharges to divert much earlier with normal xpoint position. We eventually overcame this priblem by moving the xpoint up to meet the plasma, then letting it come back down. Some care was required to avoid railing the EF2L supply (at zero current), as on shot 10. It should also be noted that the EF1L recharged to near or above the pre-charge level (~-6kA) in these cases, consistent with higher ZXL. During this part of the run I also got rid of a lot of feedforward voltages in seg2, dropped IC_EF4, tweaked around with density and Ip program and gains. See logbook for details. Around shot#15 we were getting it to divert at about 0.22sec. Shot 16 had a TF crowbar before t=0, but the plasma continued more or less normally, diverting around 0.2sec. Both the initial clearin ramp and the drop in Zcur were pushed earlier for these cases. There was about a 90minute delay while the engineers checked out the TF power supply. It turns out there had been related unnoticed converter current sharing issues for about two weeks before this event. After a lot of examination and checking and reseating of connections, the problem did not recur. We decided to go on to the slowest Ip ramp case of Step4 to verify that we could maintain the earlier diversion with potentially even higher li in that case. This shot had the same early program, but the ramp was slowed to reach 600kA at 1.0sec instead of 0.5. These shots were successful, diverting around the same time (~.2sec), and we went back to pushing for earlier diversion. Some reprogramming of the density rise (slower) seemed to help eliminate a marfe event early in the second Ip ramp, and generally improved things. Shots 19 and 22 were very good cases. For the last several shots we moved the seg2 start to 0.08 sec, ehich necessitated turning some gains in seg2 on earlier. Shot 22, which diverted at 0.18sec, had increased clearin P gain of 10, staring at .08sec, and a weak integral gain (0.5) starting at .1sec. It also had RXL programmed at -.01 instead of 0. from the beginning. The initial xpoint was near the outer nose, so even more negative RXL might be helpful. This case diverted with 290kA and li=2.3. LH and ICRF were firing at 0.7 and 1.2sec most of the day. I think they tried overlapping at some point, but I was too busy with the early shot to pay much attention. Runaways were a problem all day. Most shots had both an early bounce and runaways building up over the first 200ms. Shots 19 and 22 were exceptions. There was also one bouncy fizzle (#20). I never found any way to get rid of these, and they probably were contributing to the high li and difficulty in early diverting. I made one attempt to increase the Bz ramp rate before 15msec by tweaking the early oh1 and ef3 voltage, but it did not help much. I didn't want to change RCUR offset because that might have screwed up the slow rise phase in seg1 after the early crowbar, but perhaps that should have been tried. Note that I kept the offset=1500 from 1050708019 rather than changing to 1800, as on more recent shots. All in all, this was a pretty good run from the physop perspective. A new startup/current ramp tool has been developed. Some additional improvements look possible, but overall the main goals were met. Scorecard: ----------- Tests 0 Duds 1 (No TF) Fizzles 1 Plasmas 20 (18 full length) ========= == Shots 22 Total plasma duration: 37.38 s |
| Session Leader Comments | |||
| Apr 12 2007 10:17:15:040AM | 1070412002 | Chuck Kessel | NICE, Ip ramp is good, top of early Ip rise at 250 kA, diverting at 0.54 s, good flattop, steady-ish density at 6.5x10^19 |
| Apr 12 2007 01:35:32:163PM | 1070412012 | Chuck Kessel | good shot, divert at 280 ms, got rid of 2nd long time runaway lobe ---> slight shift in Ip gain to earlier time, back off on ZXL request |
| Apr 12 2007 04:05:55:253PM | 1070412017 | Chuck Kessel | first test of Ip ramp to 600 kA at 1000ms, with same early ramp phase to 200 kA, looks OK, has early divert with a bounce, BUT big density rise and has the long time runaway phase 200-400 ms, |
| Apr 12 2007 04:38:54:233PM | 1070412019 | Chuck Kessel | GOOD shot, Ip up to 600 kA by 1000ms, tri-linear ramp with 400 kA at 250 ms, removed runaways, density is good, inner gap is very good, divert time about 180 ms |
| Apr 12 2007 05:23:21:047PM | 1070412022 | Chuck Kessel | great final shot, early divert 180 ms, slowest Ip ramp, X-rays mostly out of the picture, left gap comes on and stays on well, li appears to respond to diverting, Te higher at 1.5 keV. Found a promising knob for even earlier diverting time RXL to keep away from the outboard shelf (the nose). |
| Physics Operator Comments | |||
| Apr 11 2007 04:38:40:540PM | Steve Wolfe |
Start setting up tomorrow's shot.
Starting from 1050708019.
Recall mag predictors in seg1 and seg2.
Seg 1: Put Br0 offset to -.0007 (current value)
IC_EF4 from -1335 from -1310
Use RCUR offset=1500 instead of recent 1800
Seg 2: Change current flattop to 600kA.
Import seg3 and seg 4 from 1070411023 (last shot, unused)
I just don't want to have to re-call all those predictors,
and it gives me a place to copy the B21_PROJ wire from.
Back in seg2, copy wire 9 from seg3 B21_PROJ, change IntC gate to 0.2,
Zero ACOIL_CUR in Seg2 V#01-16.
Buildall; touch wire 5 (I've got to fix that timestamp bug!)
Buildall.
Save as /home/wolfe/pcs_scratch/*_1070412000
NUM LONG = 3
copying /home/wolfe/pcs_scratch/pcs_model.tree to /home/wolfe/pcs_scratch/pcs_1070412000.tree
copying /home/wolfe/pcs_scratch/pcs_model.characteristics to /home/wolfe/pcs_scratch/pcs_1070412000.characteristics
copying /home/wolfe/pcs_scratch/pcs_model.datafile to /home/wolfe/pcs_scratch/pcs_1070412000.datafile
looking for.../home/wolfe/pcs_scratch/dpcs_model
NUM LONG = 3
copying /home/wolfe/pcs_scratch/dpcs_model.tree to /home/wolfe/pcs_scratch/dpcs_1070412000.tree
copying /home/wolfe/pcs_scratch/dpcs_model.characteristics to /home/wolfe/pcs_scratch/dpcs_1070412000.characteristics
copying /home/wolfe/pcs_scratch/dpcs_model.datafile to /home/wolfe/pcs_scratch/dpcs_1070412000.datafile
Open tree /home/wolfe/pcs_scratch -1
Open tree done
| |
| Apr 12 2007 07:32:17:207AM | Steve Wolfe |
Continuing setup for slow Ipdot experiment MP#466
Load From scratch 1070412000
Seg1 pg4 from 19 to 23 ms
Seg2: Remove step in OH1_VOLT after .7sec (leftover from current ramp)
Hold at 50V. Should probably drop OH2_*_VOLT from 20 to 10,
but leave it for now.
Load at 12-Apr-2007 07:23:01.00
Open tree /home/wolfe/pcs_scratch -1
Open tree done
Note that the seg1 rcur controller is hand-made, uses only
OH stack and EF3. Consider tuning it, or switching in contihh
at 50-70ms or so.
| |
| Apr 12 2007 09:30:41:070AM | 1070412001 | Steve Wolfe | Shot#1: First try at 300kA early Ip, ramp to 600kA at 0.5sec Lots of runaways but it ran. Start at 0.1sec. Move pg3 gas to 15ms in seg 1, delay nl04 a little in seg2. Increase pg4 to 24ms from 23ms Move oh comms to .05sec, smooth oh1_volt drop between 35 and 55ms Drop ip prog to 250 in seg 1 and 2, change seg2 Ip gain switch from 8@.356 to 6@.250 Turns out the LH was on at 0.1sec, that's where the runaways come from. Undo the pg3 move in seg1. |
| Apr 12 2007 10:10:20:397AM | 1070412002 | Steve Wolfe | Shot#2: Aim for 250kA delay nl04 a little in seg2. Increase pg4 to 24ms from 23ms Move oh comms to .05sec, smooth oh1_volt drop between 35 and 55ms Drop ip prog to 250 at 0.1sec in seg 1 and 2, change seg2 Ip gain switch from 8@.356 to 6@.250 plasma, 220kA at 50ms, 260 at .1sec, 600@0.5sec, smoother rise, can still see the gain switch. Also maybe want to back off EF1 current rise. Seems to be a runaway dump at ~50msec |
| Apr 12 2007 10:26:14:357AM | 1070412003 | Steve Wolfe | Shot#3: Aim for 200kA Ip target to 200ka @0.1sec (both segs) Drop OH1_VOLT to zero at 40msec (from 50V) EF3_VOLT from 2300 to 2200 at 46ms Plasma, still some early runaways. Current didn't come down much from #2, now 245 at 0.1sec. Next: Move oh crowbar from .05 to .04 |
| Apr 12 2007 10:43:40:457AM | 1070412004 | Steve Wolfe | Shot#4: Still aiming for 200kA Move oh crowbar from .05 to .04 Drop EF1_Volt demands from 145V to 0 at 50msec in seg 1 (IC_EF1 gains off at 0-, back on at 60msec) Next time remember to fill in the gas after 40msec Plasma, 190kA at 75msec, as we wanted. About 210 at 100msec Still an extra step in seg2 current rise, EF1's turn around after crowbar. Density rise very not smooth. Early bounce, runaway dump around 30msec. Plasma may move in a little 50-70ms? Next: start playing with EF1 crowbars. fill in density rise. |
| Apr 12 2007 10:59:27:413AM | 1070412005 | Steve Wolfe | Shot#5:EF1 crowbar from .2 to .12 sec, Change 150V EF1_VOLT step from .2 to .12sec,0 at .2sec Fill in seg1 pg3 pulse. Runaways worse, disruption at 1.6sec. Next: Up 2ms on pg4, move pg3 to 15ms (runaways) Try to move divertor earlier. |
| Apr 12 2007 11:27:35:660AM | 1070412006 | Steve Wolfe | Shot#6: Pg4 from 24 to 26ms, start pg3 at 15ms IC_EF4 from -1335 to -1325 CLEARIN from .002 to .01, RCUR out by 4mm, all starintg at .258 Also drop ZXU by 2cm (.06 to .04) Runaways still bad. Bounces worse. outer gap too small at .3 to .4 Next: still tuning divertor onset |
| Apr 12 2007 11:47:05:777AM | 1070412007 | Steve Wolfe | Shot#7: Move RCUR in 5mm before .5 sec, keep it off the limiter Get rid of EF1_VOLT in seg2, no compensation at crowbar. Move EF1 crowbar from .12 to .09sec Runaways still there, benign neglect didn't work. Crowbarring EF1's gave us more EF1 current early, but still doesn't get diverted any earlier. If the plasma won't come to the xpoint, let the xpoint come to the plasma: reprogram RXL, ZXL. |
| Apr 12 2007 12:00:10:313PM | 1070412008 | Steve Wolfe | Shot#8: Leave RXL at 0 straiht across (was 5mm out early, probably s noop) Keep ZXL higher until 500msec Don't know what to do about the runaways, try dropping PG4 to 26 to 22msec Runaways are very reproducible. So is late divertor. Move ZXL up, ZCUR a little further down. |
| Apr 12 2007 12:17:01:307PM | 1070412009 | Steve Wolfe | Shot#9: ZXL up by 3cm from 0.1 to 0.4 ZCUR from -.009 to -.02; Rcur a bit in between .4 and .6sec Plasmas, runaways, xpoint came up, but still slow to divert. Next: EF2_VOLT to zero in seg2, Raise ZXL some more |
| Apr 12 2007 12:30:19:420PM | 1070412010 | Steve Wolfe | Shot#10: EF2_VOLT to zero in seg2, Raise ZXL some more plasma xpoint moved, EF2 still going positive. Diverts at same time (roughly) OH2 feedforward could be turned down, move both xpoints closer. |
| Apr 12 2007 01:00:05:337PM | 1070412011 | Steve Wolfe | Shot#11: OH2_VOLTs to zero in seg2 after .11 ZXL to .06, ZXU down to 0.02. Disruption at 0.56sec, actually diverted at 0.33 Something bad happened at 0.45, chopper floors, EF2L went to zero current at 0.37sec, EF1L is going more negative than pre-charge. Back off that zxl |
| Apr 12 2007 01:20:22:550PM | 1070412012 | Steve Wolfe | Shot#12: ZXL from .06 to .05, IC_EF4 from 2000 to 1000 RCUR in by 3mm before .55sec Start Ip gain 6@130msec instead of 250 go for a smoother Ip rise. plasma full length fwwer runaways. Diverted at btween .28 and .3, with li=2.05 Looks calm and comfy, outer gap is bigger. EF2L comes up to -500A, then back down. |
| Apr 12 2007 01:26:48:580PM | 1070412013 | Steve Wolfe | Shot#13: Add an Ip point at 230ms, 350kA Runaways are back, plasma endured. Still diverting around 280msec. Try bring CLEARIN up sooner, further |
| Apr 12 2007 01:44:03:433PM | 1070412014 | Steve Wolfe | Shot#14: Start CLEARIN ramp at .110 (from .150s) ramp to .015@0.2s (was .01@.258); Start CLEARIN P-gain at 7.5 (was 5) Increase initial Ip gain from 6 to 8 No TF. |
| Apr 12 2007 01:53:54:890PM | 1070412015 | Steve Wolfe | Shot#15: Start CLEARIN ramp at .110 (from .150s) ramp to .015@0.2s (was .01@.258); Start CLEARIN P-gain at 7.5 (was 5) Early Ip gainstep at 8 (was 6). Plasma, still has an early burst of runaways Marfe .17 to .4sec Diverts at .22sec Try to get div even earlier. |
| Apr 12 2007 02:21:25:710PM | 1070412016 | Steve Wolfe | Shot#16: Start CLEARIN ramp at .10 (from .110s) ramp to .015@0.15s (was .2). TF crowbar during plasma, tripped near t=0. Plasma to 1.3sec. Still have the marfe and the runaways. Diverted at 0.2sec. There will be a fairly long delay to check and replace TF fuses. Cell access when the N2 clears. We will probably have a TF test before going back to plasma. |
| Apr 12 2007 04:02:05:313PM | 1070412017 | Steve Wolfe | Shot#17: Leave divertor program alone, try long Ip ramp: 600kA at 1.0sec (was .5sec) Turn on dpcs_ftae2 Active MHD for Jason All fuses check out. There is a TF convertor problem that's been there for two weeks, at least, possibly a bad device or fuse. All busses check ok. Gwinn thinks ok to go for plasma, can try a hipot tomorrow or next week, if it doesn't get worse. Plasma, runaways look worse. Slower than linear Ip rise before .3sec Diverts at 0.2sec, then goes back limited briefly. Density has an early rise, entre deux marfes. Xrays are rising mostly avter 0.2sec, early bounce still there, but smaller. Next: Drop OH1_VOLT and raise EF3_VOLT before 15ms. Raise density to 5e19 faster. |
| Apr 12 2007 04:13:38:803PM | 1070412018 | Steve Wolfe | Shot#18: Early OH1_VOLT plateau from 150 to 125 EF3 from 2400 to 2550. Raise nl04 faster. Initial Clearin from .015 to .018 Diverted after 180ms, stays off the wall Early bounce is worse. Long Ip pause between .1 and .25sec Try to fix Ip rise early |
| Apr 12 2007 04:26:02:243PM | 1070412019 | Steve Wolfe | Shot#19: Ip gain at 8 after .1sec, add Ip point at .3s, 400ka Zcur drop to -.02 at .16 (was .20) Slow down nl04 rise (to .4sec) No runaways and we got what we asked for on the current rise. That's a beaut! Diverts at 0.2 and stays steady, density rise looks smooth. Next: try to move divertor even earlier. |
| Apr 12 2007 04:38:58:843PM | 1070412020 | Steve Wolfe | Shot#20: Seg 2 start to .08 Make sure gains start earlier. Clearin and zcur ramp to .12sec Fizzle. Bouncer didn't make it. |
| Apr 12 2007 04:55:43:270PM | 1070412021 | Steve Wolfe | Shot#21:PG4 to 25ms from 23 Seg 2 start to .08 Make sure gains start earlier. Clearin and zcur ramp to .12sec PLasma and runaways both back Bounce is back too. Divertor at same time, 0.2sec |
| Apr 12 2007 05:13:14:590PM | 1070412022 | Steve Wolfe | Shot#22: Clearin P from 7.5 to 10 early Turn on I gain of 0.5 at 0.1sec Initial RXL at -.01 Plasma full length, no runaways. Diverts at .18sec Density rise has a bit of a bump, couple of small injections. Nice shot. No bounce on startup. Initial xpoint is still near outer nose, could have stood even more negative RXL would have been better. ICRF makes an H-mode at 1.1sec End of run. Left a good one on the drum. |
| Apr 12 2007 06:08:54:030PM | 1070412022 | Steve Wolfe | Following the run, turn off dpcs_ftae2. It turns out that the output was saturated because the AE_order in the magnetics tree was set to 1 instead of 2 (?) and the resulting frequencies were above 1MHz for these low density shots. |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 09:06:38:060AM | Plasma | Ok | |
| 2 | 10:02:26:927AM | Plasma | Ok | |
| 3 | 10:18:09:260AM | Plasma | Ok | |
| 4 | 10:34:59:907AM | Test | Bad | |
| 5 | 10:52:44:053AM | Plasma | Ok | |
| 6 | 11:20:09:140AM | Plasma | Ok | |
| 7 | 11:39:36:057AM | Plasma | Ok | |
| 8 | 11:52:22:937AM | Plasma | Ok | |
| 9 | 12:06:56:207PM | Plasma | Ok | |
| 10 | 12:21:15:447PM | Plasma | Ok | |
| 11 | 12:36:30:470PM | Plasma | Ok | |
| 12 | 01:07:44:887PM | Plasma | Ok | |
| 13 | 01:22:27:250PM | Plasma | Ok | |
| 14 | 01:34:49:053PM | Plasma | Bad | No TF |
| 15 | 01:47:02:747PM | Plasma | Ok | |
| 16 | 02:00:22:080PM | Plasma | Bad | TF Comm fault |
| 17 | 03:52:44:577PM | Plasma | Ok | |
| 18 | 04:07:47:127PM | Plasma | Ok | |
| 19 | 04:20:19:227PM | Plasma | Ok | |
| 20 | 04:35:00:983PM | Plasma | Ok | |
| 21 | 04:47:34:080PM | Plasma | Ok | |
| 22 | 05:01:10:273PM | Plasma | Ok | |
| System Availability | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Apr 12 2007 09:06:12:780AM | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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| Apr 12 2007 01:07:25:760PM | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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| Apr 12 2007 03:52:21:887PM | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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| Apr 12 2007 04:20:04:070PM | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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