Miniproposals

Miniproposal: Date Filed: Title: First Author: Session Leader: Bruce Lipschultz (shots 1-25)

Engineering Operator Run Comment

Divertor Blip/Marmer, Gwinn/Daigle

Session Leader Plans

Physics Operators Plans

Session Leader Summaries

Entered: Jul 7 2004 03:49:11:210PM

Author: To Be Determined

Run of 940617 Physics Operator - Steve Wolfe Session Leader - B. Lipschultz Engineering - F. Silva This run is based on Mini Proposal 37: Effect of Divertor Geometry on Divertor Detachment Goals: (1) Repeat 10/93 cases of detachment to determine if anything has (changed (baseline measurement). (2) Obtain a much better 'shapshot' of detachment with new diagnostics. (3) Try to obtain 'steady-state' local detachment over the outer divertor face. (4) Start process of moving the strike point and detailing effect on detachment threshold, extent and characteristics. This run will be a continuation of 940609. During that run we started the effort to reproduce detached divertor discharges. At the time we did obtain some characteristics of detachment but had trouble with the upper x-point and the inner and outer gaps. We accomplished two things during this run: (1) The divertor control was improved - upper x-point further out of the machine, and lower x-point further down (trying for z~-40 -> -41cm). The lower x-point was held fairly constant in position for the period when the plasma is diverted (> 600 ms). (2) As a sideline we looked at the Mo and C levels in the plasma in limited vs. diverted configurations We found that when the plasma diverted, the Mo and C levels dropped very quickly (< 100 ms) by ~ factor of 2. The Zeff fell much more slowly (a puzzle). We had data at a number of densities so it will be interesting to see any variation with nebar. Unfortunately, I would have to regard this run as primarily a discharge development run. We were not able to achieve a long period during the pulse over a number of shots in order to vary the density, identify the detachment threshold and examine detachment characteristics. A number of shots had fairly good equilibria which would be useful for further divertor development. For example shots 13 and 18 were good for general equilibria. Shot 24 was particularly good for diverting early but the upper x-point came in earlier than shot 18. The best shots are 5-9, 13-15, 18-20, 22, 25. The specific description of shots follow: shots 1-3: disruptive with too high a density. shot 4: disrupted, moly injections starting at .73 sec. density is lower but maybe too low. X-point at the top is too close. Steve will change EF1U to compensate. shot 5: pretty good, the upper x-point is outside the machine from 640 ms untile ~ 850 ms when it starts to creep back in. More twiddling will be tried to compensate. Also, the density dropped on this shot even though the gas was increased. Things must be cleaning up, The gas will be increased again. Mike Graf reports that when we divert (640 ms) that both CVI and Mo drop . shot 6: also good. The upper x-point position is slightly further out. shot 7: This one disrupts a litle earlier. However, the density is more constant and the lower x-point position is more constant and slightly lower. The next shot will have the first try for density feedback control by shifting segments in the control PCS at .9 seconds or so and then used to ramp down the current at 1 seconds. shot 8: The density increased to nebar~7 e 19 m^-3. The PCS test was successfull. The plasma is very dirty (Z=4) before it diverts. But afterwards, the Z decays to 1.5 evn though nebar is not varying much. The Mo levels in the plasma decay accordingly. shot 9: The lower x-point was lowered farther on this shot (z~-41 cm) to a level consistent with last fall. Its position is held very constant. The strike point on the outer divertor plate initially is low but creeps up during the shot. The density is creeping up during the shot as well. shot 10: disruption a little after 700 ms. Steve claims he got too carried away with changing the x-point R controller. He will change his changes back! shot 11: disruption again. Will reload shot 9 because we are not sure what the problem is. Modify just the gas pulse in order to flatten the density vs. time. shot 12: disruption later in time. elongation high (1.71) and density low. shot 13: reasonable length shot. Density steadily increasing through the shot. Possible divertor detachment @ 1.1 sec. shot 14: lower density for some reason. The plasma current has a hiccup at 250 ms after which things go realtively well.. Disruption at 1.1 sec. shot 15: Data acquisition problems which seem to have been overcome. Otherwise the shot looks ok with steadily increasing density up to nebar=8e19 at .97 seconds. At that point we get what looks like divertor detachment. Oddly enough, on this shot and shot 13 when we get the 'divertor detachment' the density in the main plasma decreases. The pulsed gas is steady through to 1.1 seconds indicating that whatever we see in the divertor may be correlated with the density drop in the main pl shot 16: disrupts at 1.1 sec. Otherwise nebar increasing from 5 to 7.5 e19 shot 17: disruption at .6 seconds. Divertor gas puff fired on that shot at .7 seconds to reach the plasma at .8 seconds. shot 18: Divertor gas reaches the plasma at .77 seconds. Nebar takes off and increases from 5 to 12 e19. The divertor density increases. The biggest increases in the divertor are at the separatrix and below (guessing at where the separatrix is). At those locations the density increases very quickly and then drops. Further up the divertor face the density increases like nebar and stays constant. At the time of gas puff the UV bolos drop quickly (channels 4-8) while other channels are less affected. Channels 4-8 look through the outer divertor separatrix leg. We will try to raise the initial density. shot 19: nebar screams up from 5 to 13 e 19 with divertor gas puff. There is no obvious detachment. We did not schieve the level of initial density we asked for so will try to use the divertor gas puff to raise the density before diversion. shot 20: disrupted at 1.0 seconds. nebar screams up to 2.e20. It looks like we raised nebar too much before the plasma diverted. It turns out that 2 valves were being triggered on this shot (inner wall and divertor). For the next shot we will try to reduce the gas (1 valve) and egt the density better under control. In addition we will try to shift the x-point outward in major radius to better balance the 2 divertors. shot 21: dud shot 22: shot went full length. Nebar reaches 1.3e20 but the equilibrium However we are now having a recurring problem with the upper x-point. It does not go away until 800 ms (towards the OH stack) and then continues to be not far away on the top for the rest of the shot. We don't know how much this has affected the divertor operation. shot 24: ragged. will reload shot 18 for the next shot. shot 25: Mo injection at 1. seconds. Disruption at 1.17 seconds. Hard x-rays at the beginning of the shot. Nebar ges to 1.e20.

Physics Operator Summaries

Entered: Jul 7 2004 04:36:51:927PM

Author: To Be Determined

Physics Operator Summary for 940617 SL: BLIP PO: wolfe EO: Silva,Bertolino,Daigle Divertor run, nominally MP039 but we'll start by trying to improve the equilibrium. Piggyback was MP061, the PCS segment usage and density feedback experiment. The goals were to get a reproducible, non-disruptive, diverted equilibrium, and evaluate the detachment behavior in comparison with last year's data, and in preparation for looking at slot and shelf divertor geometries. Some progress was made, but this aspect of the run was not an unqualified success (to put it mildly). The goal of the piggyback was to get the segment copying and switching to work in a live situation. Since the density feedback signal was not available, only the PCS aspects of the experiment were attempted. This aspect of the run was successful, although some of the software will not be available in the public versions of the code until next week. We got off to an early, but not particularly auspicious start, taking the fiducial shot (Loaded from 940603015) at 8:15am. The fiducial shot disrupted at 0.87 sec. The first shot of the day's experimental program was a reload of 940615010, a good 700ka diverted shot from Wednesday; this shot also disrupted, apparently from too high a gas puff, although it had run successfully on Wednesday. The fact that there was a short time after the completion of ECDC until the start of the run may have been responsible for some of the problems. After several iterations of reducing the gas, and a change to the IC_EF1U programming and to the early RXL waveform, shot 5 ran to 1.4 sec. Note: the change in the RXL, made to reduce the error at the time the control turned on, was too large for the value of factor; this was not noticed at the time (either the acknowledge widget didn't pop up or I forgot about seeing it). Nevertheless, it seemed to do the right thing, i.e. produced a good shot. A subsequent attempt to fix it by reducing the vale of factor led to a disruptive shot, and the "bad" value was put back and left till the end of the run. Shots 6 and 7 involved some changes to ZCUR and ZXL waveform programming, the addition of the EF2's to the slow ZCUR controller (a good thing), and a change in the IC_EF4 to stay at +1000A until the end of the flattop, in order to help push the upper x-point out of the machine. The segment switching was tested on shot 8: Segment 1 was copied to Segment 2, using JAS private version of the code. The IP waveform in Seg 2 was then redrawn to begin rampdown at 1.0 sec instead of 1.3, and the segment was switched on at 0.9sec. This operation was successful, the current did begin rampdown at 1.0 sec, and the transition at 0.9 seconds was invisible on all traces. On shot 9, the switch time was moved earlier, to 0.3 sec, and the wire containing the IP waveform was copied using LOAD_WIRE (in the public version of PCS) from Segment 1 to Segment 2, thus putting the IP waveform back as it had been. The second segment was left active for the remainder of the run. NOTE THAT ALL CHANGES AFTER 0.3 SEC NOW MUST BE MADE TO SEGMENT 2, NOT SEGMENT 1. This took some getting used to, but was basically ok. Later in the run, we created a new fast ZCUR wire on WIRE 7 (used as BR_0 in SEGMENT 1). The nominal place for the density feedback, when it is available, is wire 9, used for IC_OH1 in Segment 1. The segment feature is now in a useful state, and I recommend it continue to be used in all future runs. Shot 9 also tested running the EF4 current even more positive, up to 2000A by the EOF, to continue pushing the upper x-point away. This seemed to work. Shot had an elongation of about 1.7, fairly constant over the main part of the flattop, and the ZXU moved from .37 to .39. Shot 10 and 11 had several changes, the combination of which resulted in early (<0.7 sec) disruptions. Shot 12 was a reload of shot 9, with the gas puff changed to try to lower the density after 0.64 sec. This disrupted at 0.85 sec. Shot 13 the IC_EF1U was raised to +2000A. The shot lasted into the rampdown phase. Elongation reduced to 1.65:1.7, and ZXU raised to 0.40 at 1 sec. After shot 13, it was noted that the ZXL Pgain was set to 10.00; this had been previously noted to cause the actual gain to go to -10.00, so I reduced it to 9. Shot 14 had runaways, and lasted until 1.1 sec. Shot 15 had increased fill pressure of 1.2e-5, and a tweak to the ZXL programming. This ran ok. There was a long delay do to a computer hang after shot 15 until the data was available. SHot 16 had a significant change to the RXL controller. The upper OH2 and EF2 were removed, leaving only OH2L and EF2L. This was successful. elongation remained nearly flat at 1.68 to 1.65, and the upper null was well out of the way. The gas was also extended to keep the density up at the end of the flattop. Shot 17 was intended as the first NINJA gas puff, at 0.7sec. Two other significant (?) changes were made: the gain of the EF2's in the slow ZCUR controller was doubled; unfortunately this was done in Segment 1, instead of in 2 as intended. Also, the new fast ZCUR wire to provide more gain for the chopper was added to Wire 7, with a P gain of 4. The shot disrupted at 0.6 sec. These changes were undone in shot 18, which turned out to be the best shot of the day. This shot made it all the way down in the rampdown phase, even longer than shot 5. The upper null was well out of the machine, the elongation was nearly flat at 1.65: 1.7, and the lower x-point height was around -.4m. The RXL was about 1cm inside of optimum. NINJA fired at 0.7sec, with the A-side puff off from 0.8sec. Shots 19 and 20 were the same programming, except for adjustments to the gas. Shot 20 had the current flattop extended to 1.3 sec, along with all the other relevant P waveforms, and the IP controllers. However, it disrupted at around 1second. This was a hard, downward disruption that apparently killed the H divertor shunt, although this was not discovered until later. Shot 21 was a dud. It was noted that the RF assist had tripped on shot 20, so the RF was off for 20 and 21. Shot 22 was a repeat, with RF assist at breakdown. The ZXL gain (actually, the EF1L controller, as the gain was essentially maxxed out) was increased, and RXL was moved out to +.01. This was a long shot, making it into though not through rampdown. However, the upper x-point was closer in and the elongation was back up to the 1.75:1.8 range. There were definite signs of vertical oscillations through much of the flattop. Shot 23-25 all had significant non-thermals, although nothing in the startup segment (SEGMENT 1) had been touched. It is possible that the plenum pressure had dropped and the early gas puff was affected. Shot 24 was an attempt to change the early EF1L current to better correspond to the behavior last October. IN particular, the current at .5sec changed from near zero to -2000Amps, and ramped up to zero at 1 sec. The shape around the lower x-point was better for this shot, but the elongation was constantly increasing, and the upper x-point was too close late in the shot. However, the evolution from limited to diverted was much nicer, eliminating the sweep of the x-point across the inner nose. This programming, at least between .3 sec and .6 sec, should be pursued, I think. Shot 25 was a reload of shot 18, with current flattop extended to 1.3sec. It disrupted before rampdown and had significant runaways. However, the elongation was flat at 1.65:1.7, and the upper null was reasonably far away. Summary: -------- From the operations standpoint, significant progress was made in getting the upper null pushed up and reducing the elongation while maintaining reasonable gaps. Two successful rampdowns were obtained, but the late flattop and rampdown are still prone to disruptions. There was a tendency noted for the current to start to sag at about 1 sec, for unknown reasons. The ZXL position was lowered to where BLIP wanted it, but never seemed well-controlled. RXL control with just the OH2L and EF2L works well. The EF2's were added to the slow ZCUR control, and this seemed to help. Recommendations: --------------- It is clear we need to move away from coil current control, and toward shape control. This was not accomplished today. A good starting point might be shot 18. Control of the elongation, or of ZXU, using the EF1U,EF2U and possibly EF4 would be a natural step. In terms of the divertor formation stage (0.4 to 0.6 sec), it seems that programming of EF1L along the lines of shot 24 could be a big win. The segment switching is working, and should be kept on; just try to remember to make changes in the appropriate segment. The startup (Segment 1) can be largely left alone. It is possible that an earlier switch time, say around .2sec instead of .30, should be tried. The nice thing is, if it doesn't work you just have to change one number back. The density feedback hardware should be available on Tuesday, and should be tried ASAP. A lot of time was wasted because the density wouldn't stay put from shot to shot. This is especially important as the response to the gas changes so dramatically in this type of experiment, at the limited-diverted transition, at the divertor detachment, etc. Scorecard: ---------- Duds 1 Fizzles 0 Plasmas 24 (non-disruptive: 2) -------- -- Total 25

Session Leader Comments
Jun 17 1994 08:42:16:980AM	940617002	Bruce Lipschultz	shot 2: disrupted, looks like full poloidal detachment leading to disruption. lower gas for next shot.
Jun 17 1994 08:43:24:830AM	940617002	Bruce Lipschultz	shot 2: disrupted, looks like full poloidal detachment leading to disruption. lower gas for next shot.
Jun 17 1994 09:08:58:590AM	940617002	Bruce Lipschultz	shot3: disrupted, moly injection at .46 sec. Looks like the gas is still high.
Jun 17 1994 09:36:13:340AM	940617004	Bruce Lipschultz	shot 4: disrupted, moly injections starting at .73 sec. density is lower but maybe too low. X-point at the top is too close. Steve will change EF1U to compensate.
Jun 17 1994 09:56:04:250AM	940617005	Bruce Lipschultz	shot 5: pretty good, the upper x-point is outside the machine from 640 ms until ~ 850 ms when it starts to creep back in. More twiddling will be tried to compensate. Also, the density dropped on this shot even though the gas was increased. Things must be cleaning up, The gas will be increased again. Mike Graf reports that when we divert (640 ms) that both CVI and Mo drop .
Jun 17 1994 10:16:53:680AM	940617006	Bruce Lipschultz	shot 6: also good. The upper x-point position is slightly further out. This shot seems cleaner. The density is still low but will compensate again on the next shot.
Jun 17 1994 10:45:55:880AM	940617007	Bruce Lipschultz	shot 7: This one disrupts a litle earlier. However, the density is more constant and the lower x-point position is more constant and slightly lower. The next shot will have the first try for density feedback control by shifting segments in the control PCS at .9 seconds or so and then used to ramp down the current at 1 seconds.
Jun 17 1994 11:15:30:350AM	940617008	Bruce Lipschultz	shot 8: The density increased to nebar~7 e 19 m^-3. The PCS test was successful The plasma is very dirty (Z=4) before it diverts. But afterwards, the Z decays to 1.5 evn though nebar is not varying much. The Mo levels in the plasma decay accordingly. Brian will insert the scanning probe on the next shot.
Jun 17 1994 11:43:38:740AM	940617009	Bruce Lipschultz	shot 9: The lower x-point was lowered farther on this shot (z~-41 cm) to a level consistent with last fall. Its position is held very constant. The strike point on the outer divertor plate initially is low but creeps up during the shot. The density is creeping up during the shot as well.
Jun 17 1994 11:59:37:280AM	940617010	Bruce Lipschultz	shot 10: disruption a little after 700 ms. Steve claims he got too carried away with changing the x-point R controller. He will change his changes back!
Jun 17 1994 12:09:43:430PM	940617011	Bruce Lipschultz	shot 11: disruption again. Will reload shot 9 because we are not sure what the problem is. Modify just the gas pulse in order to flatten the density vs. time.
Jun 17 1994 12:29:38:430PM	940617012	Bruce Lipschultz	shot 12: disruption later in time. elongation high (1.71) and density low.
Jun 17 1994 01:00:07:440PM	940617013	Bruce Lipschultz	shot 13: reasonable length shot. Density steadily increasing through the shot. Possible divertor detachment @ 1.1 sec.
Jun 17 1994 01:17:01:830PM	940617014	Bruce Lipschultz	shot 14: lower density for some reason. The plasma current has a hiccup at 250 ms after which things go realtively well.. Disruption at 1.1 sec.
Jun 17 1994 01:54:48:690PM	940617015	Bruce Lipschultz	shot 15: Data acquisition problems which seem to have been overcome. Otherwise the shot looks ok with steadily increasing density up to nebar=8e19 at .97 seconds. At that point we get what looks like divertor detachment. Oddly enough, on this shot and shot 13 when we get the 'divertor detachment' the density in the main plasma decreases. The pulsed gas is steady through to 1.1 seconds indicating that whatever we see in the divertor may be correlated with the density drop in the main plasma.
Jun 17 1994 02:18:43:310PM	940617016	Bruce Lipschultz	shot 16: disrupts at 1.1 sec. Otherwise nebar increasing from 5 to 7.5 e19
Jun 17 1994 02:44:49:720PM	940617017	Bruce Lipschultz	shot 17: disruption at .6 seconds. Divertor gas puff fired on that shot at .7 seconds to reach the plasma at .8 seconds.
Jun 17 1994 03:05:47:810PM	940617018	Bruce Lipschultz	shot 18: Divertor gas reaches the plasma at .77 seconds. Nebar takes off and increases from 5 to 12 e19. The divertor density increases. The biggest increases in the divertor are at the separatrix and below (guessing at where the separatrix is). At those locations the density increases very quickly and then drops. Further up the divertor face the density increases like nebar and stays constant. At the time of gas puff the UV bolos drop quickly (channels 4-8) while other channels are less affected. Channels 4-8 look through the outer divertor separatrix leg. We will try to raise the initial density
Jun 17 1994 03:21:59:290PM	940617019	Bruce Lipschultz	shot 19: nebar screams up from 5 to 13 e 19 with divertor gas puff. There is no obvious detachment. We did not schieve the level of initial density we asked for so will try to use the divertor gas puff to raise the density before diversion.
Jun 17 1994 03:42:21:640PM	940617020	Bruce Lipschultz	shot 20: disrupted at 1.0 seconds. nebar screams up to 2.e20. It looks like we raised nebar too much before the plasma diverted. It turns out that 2 valves were being triggered on this shot (inner wall and divertor). For the next shot we will try to reduce the gas (1 valve) and egt the density better under control. In addition we will try to shift the x-point outward in major radius to better balance the 2 divertors.
Jun 17 1994 03:49:07:020PM	940617020	Bruce Lipschultz	shot 20: disrupted at 1.0 seconds. nebar screams up to 2.e20. It looks like we raised nebar too much before the plasma diverted. It turns out that 2 valves were being triggered on this shot (inner wall and divertor). For the next shot we will try to reduce the gas (1 valve) and egt the density better under control. In addition we will try to shift the x-point outward in major radius to better balance the 2 divertors.
Jun 17 1994 03:51:44:140PM	940617021	Bruce Lipschultz	shot 21: dud, maybe because the rf-assist tripped out after shot 19?
Jun 17 1994 04:15:36:070PM	940617022	Bruce Lipschultz	shot 22: shot went full length. Nebar reaches 1.3e20 but the equilibrium However we are now having a recurring problem with the upper x-point. It does not go away until 800 ms (towards the OH stack) and then continues to be not far away on the top for the rest of the shot. We don't know how much this has affected the divertor operation.
Jun 17 1994 05:02:44:940PM	940617024	Bruce Lipschultz	shot 24: ragged. will reload shot 18 for the next shot.
Jun 17 1994 05:06:55:710PM	940617025	Bruce Lipschultz	shot 25: Mo injection at 1. seconds. Disruption at 1.17 seconds. Hard x-rays at the beginning of the shot. Nebar ges to 1.e20.

Physics Operator Comments
Jun 17 1994 08:00:50:710AM		Steve Wolfe	Divertor run, nominally MP039 but we'll start by trying to improve the equilibrium. I'll be starting (after the fiducial) from 940615010. Horne and Stillerman will be trying out the segment copy and switching on shots 2-4. The density feedback isn't actually ready.
Jun 17 1994 08:24:40:490AM	940617001	Steve Wolfe	Shot #940617001 ---------------- Fiducial shot, loaded 940603015. Result: ------- Disrupted at .87 sec It seems to have diverted at 0.5sec ?
Jun 17 1994 08:36:16:590AM	940617002	Steve Wolfe	Shot #940617002 ---------------- Loaded from 940615010 Result: ------- Disrupted about the same time.
Jun 17 1994 08:43:14:400AM	940617002	Steve Wolfe	Shot #940617003 ---------------- Turn off second Argon pulse Reduce D2 gas puff. Horne and JAS will now copy seg1 to seg2 using their private copy of PCS Result: -------
Jun 17 1994 09:04:46:050AM	940617003	Steve Wolfe	shot 940617003: ----------------- NO segment switching was tried, but the segment 2 is loaded as a copy of segment 1. Gas changes as indicated. Result: --------- Disrupts at 0.64. Big injections at .48
Jun 17 1994 09:25:34:150AM	940617004	Steve Wolfe	shot 940617004: ----------------- Reduced gas a lot (from 45 to 25 over must of the shot) PCS load into model seemed to do a lot more stuff than usual. Result: --------- Disrupts at .92 sec. INjections at .72 and after. looks like moly.
Jun 17 1994 09:48:42:130AM	940617005	Steve Wolfe	shot 940617005: ----------------- Increase EF1U to 1100A Redraw RXL to match the initial error a little better. INcrease gas after 550msec Result: --------- Better. Makes it down to 200kA, at 1.4 sec Equilibrium looks pretty good.
Jun 17 1994 10:03:18:570AM	940617006	Steve Wolfe	shot 940617006: ----------------- Raise gas to 30 V again. (density was very low late.) Add EF2 U&L to slow ZCUR control (gain = +/- 2.5e-3, same as OH2's) Hold EF4 at +1000 A until 1.2sec. Result: --------- Disrupted earlier, around 1.14;got crowbars. Still low density after .5 sec.
Jun 17 1994 10:31:34:370AM	940617007	Steve Wolfe	shot 940617007: ----------------- Raise gas puff back to 40V Program ZXL lower by 1cm, and falling by another .5cm Start drop in ZCUR at .4 sec Result: --------- Disrupted late,(1.11) still not making it to ramp down. For next shot, leave everything the same, but let SFH and JAS do a segment switch, and start curretn rampdown at 1.0se.
Jun 17 1994 10:35:51:020AM	940617007	Steve Wolfe	for shot 940617008 - Copy seg1 to seg2, switch at .9 seconds. begin rampdown at 1.0
Jun 17 1994 10:52:56:410AM	940617008	Steve Wolfe	shot 940617008 - Segment switch at .9 worked. Rampdown started at 1.0 second as drawn in segment 2. Died at same time as 940617007 - we did not adjust the controller when we moved the ramp down.
Jun 17 1994 11:27:16:190AM	940617009	Steve Wolfe	shot 940617009 - Change switch to 0.3 All changes after that time must now be made to SEGMENT 2!!!!!! INcrease gas between .45 and .65 to 40V Put seg 1 IP waveform back by LOAD_WIRE (in SEG2) Ramp EF4 to 2000A between .3 sec and 1.2 sec Increase width of first Ar pulse by 2msec. Result: ------- Disrupts at 1.13. Need to fix that ramp down. Density is higher. Note RXL was saturating the gain in the wavegen.
Jun 17 1994 11:56:26:820AM	940617010	Steve Wolfe	shot 940617010 - MOve RXL 1cm further out. Chnage RXL factor from 4.e-5 to 2.5e-5 Drp ZCUR to -1.5cm at 0.65, flat thereafter. Take OH2's out of RXL control. Lower gas after .64 sec from 40 to 34 Result: ------- Died earlier. Disrupted down at 0.7 sec. Loss of vertical control. OH2's were too negative, especially OH2U. We get an x-point to the inner wall.
Jun 17 1994 12:05:28:100PM	940617011	Steve Wolfe	shot 940617011 - Put OH2's back into RXL at -1.e-4 Result: ------- Looks the same? A little shorter. SImilar behavior, that must not have been it?
Jun 17 1994 12:28:58:270PM	940617012	Steve Wolfe	shot 940617012 - Reload shot 9 CHange gas puff as on shot 10. Result: ------- Disrupted at .85 again
Jun 17 1994 12:47:11:010PM	940617013	Steve Wolfe	shot 940617013 - Raise EF1U to +2000A No change in gas puff, despite Bruce's objection. Result: ------- Shot lasted longer. 1.29 sec, got into rampdown. Disruupted up for a change. Some injections, especially one at .87 (a familiar time). RXL is on target; ZXL is drifting up; CLEARIN is ok. ZXL has a P gain of 10.0000at .792 sec. This probably is a bad thing. lower it to 9.0 next shot.
Jun 17 1994 01:11:34:250PM	940617014	Steve Wolfe	shot 940617014 - Change gain point at .792 from 10.000 to 9.0 Result: ------- Xrays. LAsted until 1.1sec
Jun 17 1994 01:19:50:090PM	940617015	Steve Wolfe	shot 940617015 - Raise fill to 1.2e-5 Flatten ZXL at -2 cm Result: ------- For next shot, extend gas to 1.2 sec. (I Forgot this time). Shot ran ok, no xrays.
Jun 17 1994 01:33:50:470PM	940617015	Steve Wolfe	shot 940617015- ------- . Shot ran ok, no xrays. Data system hung up. It thinks it's still shot 14.
Jun 17 1994 02:08:34:360PM	940617016	Steve Wolfe	shot 940617016- ------- . extend gas to 1.2 sec. (I Forgot last time). Remove OH2U and EF2 U from RXL controller (OH2 was symmetric, EF2 was already down by factor of 4). Note :I had reloaded the shot with the large factor on RXL, so I got the acknowledge message again. This time I just ignored it Result: ------- Made it into ramp down (nearly). I need to extend the Fizzle detector time to 1.45.
Jun 17 1994 02:39:19:150PM	940617017	Steve Wolfe	shot 940617017- ------- . NINJA will puff this time at 0.7 (should get in at 0.8) Turn off A-side puff after 0.8sec MOved fizzle detector to 1.45 COPY wire 3 (fast ZCUR) to wire 7(was BR_0) and change gains: P=4, D=0. Raise gain of EF2's in slow ZCUR from 2.5e-3 to 5 e-3. Result: ------- Disrupted early, around 0.6sec. Note I had made the EF2 in ZCUR control change in seg1.
Jun 17 1994 02:54:48:550PM	940617018	Steve Wolfe	shot 940617018 ------- . UNdo change to seg 1 slow zcur, set ZCUR 7 gains to zero, essentially back to shot 16 except for gas Result: ------- Full length shot. Best shot of the day.
Jun 17 1994 03:08:00:710PM	940617019	Steve Wolfe	shot 940617019 ------- . Raise gas between .45 and .65 from 40 to 45V to rty to raise and flatten density Result: ------- Disrupted at 1.13. Signs of vertical instability this time. Bruce is complaining the strike point moves to much; the strike is as steady as I've ever seen it.
Jun 17 1994 03:26:56:430PM	940617020	Steve Wolfe	shot 940617020 ------- . Extend pulse length to 1.3 sec flattop Extend invert times on all supplies to 1.6,TF to 1.4 FIzzle detector to 1.55 NiNJA will pulse twice. Result: ------- Disrupted earlier, right at 1sec.
Jun 17 1994 03:51:28:040PM	940617021	Steve Wolfe	shot 940617021 ------- . Raise EF1L controller of ZXL from 2e-3 to 3.5e-3 Lower gas puff between .45 an .65 The NINJAs will adjust their puff. Move RXL out to +1cm. (Ithought we had done that, but must have undone it.) Result: ------ Dud!!! No RF on previous shot, was on on 19. Fields look fine (as fine as they have been.)
Jun 17 1994 04:12:30:520PM	940617022	Steve Wolfe	shot 940617022 ------- . Same as 21: Raise EF1L controller of ZXL from 2e-3 to 3.5e-3 Lower gas puff between .45 an .65 The NINJAs will adjust their puff. Move RXL out to +1cm. (Ithought we had done that, but must have undone it.) Result: ------ Long shot, upper x-point seems to be coming in again. Elongation was up to 1.75 at 0.8sec, at 1.2 sec to 1.79
Jun 17 1994 04:19:38:830PM	940617023	Steve Wolfe	shot 940617023 ------- . Put back gas puff between .45 an .65 The NINJAs will adjust their puff. Result: ------ xrays early. Long shot.
Jun 17 1994 04:42:51:890PM	940617024	Steve Wolfe	shot 940617024 ------- . Radical change to EF1L current programming. Hold at -2000A at .5 sec, then ramp linearly through 0 at 1 sec, to +1000 or so at 1.3. Result: ------ Disrupted at 0.95. ZXL was apparently high, but no worse than earlier. It still has runaways.
Jun 17 1994 05:11:29:050PM	940617025	Steve Wolfe	shot 940617025 ------- . reload shot 940617018, Extend shot to 1.3sec flattop. Result: ------ More xrays. Disrupted before rampdown. Needed more early gas puff.

Engineering Operator Comments
Shot	Time	Type	Status	Comment
1	08:14:49:670AM	Plasma	Ok	fiducial shot disruption 875 ms time of shot 08:17
2	08:29:10:710AM	Plasma	Ok	disruption fiducial repeat
3	08:53:23:010AM	Plasma	Ok	disruption comm fault oh2l
4	09:14:29:060AM	Plasma	Ok	disruption
5	09:35:51:030AM	Plasma	Ok	better
6	09:56:32:900AM	Plasma	Ok	disruption comm fail oh1, oh2u
7	10:17:40:290AM	Plasma	Ok	comm fault oh1, oh2u disruption
8	10:47:14:040AM	Plasma	Ok	no faults disruption
9	11:18:35:530AM	Plasma	Ok	no faults disruption
10	11:44:08:980AM	Plasma	Ok	disruption - ef1l comm fault
11	12:00:43:410PM	Plasma	Ok	no faults
12	12:17:45:640PM	Plasma	Ok	no faults
13	12:35:06:830PM	Plasma	Ok	disruption and comm faults
14	12:53:28:700PM	Plasma	Ok	no faults
15	01:16:52:590PM	Plasma	Bad
16	01:58:43:730PM	Plasma	Ok	No faults
17	02:19:43:710PM	Plasma	Ok	No faults.
18	02:42:36:000PM	Plasma	Ok	No faults.
19	02:59:26:800PM	Plasma	Ok	No faults.
20	03:23:34:230PM	Plasma	Ok	No faults
21	03:42:50:100PM	Plasma	Ok	No faults.
22	03:56:14:010PM	Plasma	Ok	No faults
23	04:14:35:320PM	Plasma	Ok	comm faults late in inversion,no effect on shot.
24	04:34:12:050PM	Plasma	Ok	No faults.
25	04:55:49:380PM	Plasma	Ok	comm fault OH2l, EF1u, OH1.