Miniproposals

Miniproposal: Date Filed: Title: First Author: Session Leader: Unknown (shots 1-15)

Miniproposal: 196a Date Filed: 12/16/1997 Title: High SOL Density Shots for the Calibration First Author: Yijun Lin Session Leader: Yijun Lin (shots 29-34)

Miniproposal: 197 Date Filed: 11/5/1997 Title: Helium Probe Comparison with Fast Scanning Probe First Author: Spencer Pitcher Session Leader: Spencer Pitcher (shots 13-28)

Engineering Operator Run Comment

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Session Leader Plans

Physics Operators Plans

Session Leader Summaries

Entered: Jul 7 2004 03:49:17:727PM

Author: To Be Determined

MP196A High SOL Density Shots for the Calibration of Reflectometer Profiles ------ -------------------------------------------------------------------- The point of this MP was to drive the density up at the edge so high we could feel confident that all the reflectometer channels were reflecting from nearly the same location -- the limiter. The run sequence plan was completed very successfully: 1) produce a linear ramp in density with as high a density as possible ( up to 4 X 10^20 m-3) with standard outer gap -- shots 29-30 2) repeat but with 0.5 cm gap -- shot 31 3) scan outer gap during shot from approx 2 cm to < .5 cm -- shot 32 4) repeat -- shot 33 5) try for a plasma limited on the outer limiter -- shot 34 The most obvious effects were seen in step (5) where all the channels responded to some degree as the plasma moved out onto the limiter. This shot was also the only one during which the 110 GHz channel really seemed to be well outside and within range of the other channels. A problem with the fluctuation measurements was discovered during this run. A 150 kHz oscillation is present on the fast channels that has nothing to do with the plasma. We are trying to fix this problem now.

Entered: Jul 7 2004 03:49:17:740PM

Author: To Be Determined

Session Leader's summary of run 980106 MP 197 Helium Beam Check-Out SL: CSP (Pitcher) PO: Granetz ----------------------------------------------------------- Basic Plan: Today we will be comparing the helium beam with the fast-scanning probe (FSP). The helium beam has only sparse spatial coverage, ie delta_r ~ 7 mm, and thus to obtain high resolution profiles we will be 'scanning the plasma' by changing the outer gap slowly over 700 ms approx. The FSP will scan at three times, first to ensure the SOL is not evolving during the gap scan, and second, to compare with the helium beam results. The experiment will be performed in Ohmic discharges first and then in RF discharges, a few densities will be used. We also have a piggy-back experiment....Jim Weaver will be trying to make helium II and Halpha drift measurements in the divertor. Contrasting these will shed light on the question of plasma pressure loss in the divertor due to plasma-neutral friction. In the first part of the day we will be running several fiducials to re-establish operation after the holidays. ----------------------------------------------------------- shot 02 - Lower divertor capillary plenum filled to 7 psi of helium (Bob is wrong.) shot 07 - density rises at .35 s, also fside ratiomatic, Halpha looks like entering dithering Ohmic H-mode. Loop voltage, ie Ohmic power high 1.6 MW. Dithering Ohmic H-mode??? maybe? *****************NOW START MP197***************************** shot 12 - next shot - first helium puff thru AB limiter shot 13 - helium puff thru AB limiter delta_t = 0.1 s starting at 0.15 s @ 7 psia - FSP moving in silo only - Weaver on HeII, Chromex on helium red lines * Weaver computer glitch ... no data * Chromex satruated on 600 line grating shot 14 - helium puff increased to dt = 0.2 @ 0.15 s - chromex changed to 1200 line grating * plasma disrupts at 0.35 s shot 15 - ninja plenum changed to 3 psia helium t = .15 s, dt = 0.2 - chromex on 600 line grating * fizzle shot 16 - ninja t = 0.15 s, dt = .1 s - chromex NOT saturated, although Halpha interference? shot 17 - FSP to go on this shot - tweak chromex to reduce Halpha interference * good shot, nl4 = 1.0e20, FSP and chromex data both good shot 18 - drop density, keep all else the same * density not quite flat * fsp and chromex good shot 19 - repeat from last shot * density behaviour no better....abandon shot 20 - go back to nl4 = 1.0e20 - shift ninja gas to inner wall (B16-001) for background check * good fsp and chromex data shot 21 - go to nl4 = 1.5e20 - shift ninja gas to AB limiter again - fsp stays out * upper marfe seen on TV * valves wide open but only got nl4 ~ 1.3e20 * chromex data good shot 22 - repeat shot 21 - fsp will go * good chromex and fsp data shot 23 - repeat shot 22 + 1.5 MW ICRH from t = 0.4 to 1.2 s - fsp off * weird shot...starts off ELM-free H-mode with typical signatures. Following a single giant ELM we go into a steady-state ELM-free LOW D-alpha H-mode? or is it enhanced D-alpha H-mode? shot 24 - repeat of shot 23 - fsp will go - ninja gas shifted to inner wall for background check * good fsp and chromex data * again a new beastie....no large elm this time shot 25 - repeat of shot 24 - fsp will go - ninja moved to AB limiter * good fsp and chromex data * new beastie again * Halpha rises towards end of shot, no large elm shot 26 - attempt at lowering density * very messy shot, series of elm-free periods shot 27 - go back to shot 23, nl4 = 1.5e20, Ohmic, ninja gas to inner wall for background check * chromex and fsp ok shot 28 - go back to shot 19, nl4 ~ 0.7e20, Ohmic, ninja gas to inner wall for background check * chromex and fsp ok * LAST SHOT OF THIS MINI-PROPOSAL ----------------------------------------------------------- WHAT WAS ACTUALLY ACCOMPLISHED: Start-up was slow after the holiday break. (MP197 didn't start until shot 13.) The machine had symptoms of being dirty, and this might have been exacerbated by the presence of argon. By shot 13, the machine was running better and we starting mp 197. By this point the argon didn't seem to affect things. Shots 14,15 were bad, but all the rest, ie 16 thru 28 were good discharges. We compared the helium beam and FSP at low, medium and high density in Ohmic discharges. For each of these densities, a 'background discharge' was taken, where the AB limiter gas puff was turned off and the same quantity of helium was gas puffed at the inner wall. This provided a background helium recycling level, which is possibly important for some of the helium beam spatial channels. Both the chromex data from the helium beam and the FSP data look very good, with nice robust, noise-free signals. The detailed comparison between the two remains to be done. Unfortunately, the piggy-back experiment, ie He II drift measurements in the divertor, could not be properly carried out, as the helium level required by Jim Weaver was far too high for the chromex spectrometer, ie it saturated the chromex. Instead, Jim focussed on Halpha measurements and in a few cases B II. In shots 23 - 26 we injected 1.7 MW ICRH and found what appeared to be a new type of H-mode (albeit with poor confinement, ie H_iter89 ~ 1.3 to 1.5). These plasmas (eg shot 24) achieved steady-state conditions, but were significantly different than standard EDA H-modes. For example, comparing shot 24 with 971216031 (-- a reasonable EDA shot), the neutral density in the divertor and at the midplane were similar, but the H-alpha was radically different, ~ 0.7 in shot 24 and ~ 5 in EDA, ie shot 24 was more like an elm-free H-mode, BUT STEADY-STATE! Further, the radiated power and Mo impurity level were much higher in shot 24, ie 60% and 3e15, respectively, compared with 30% and 0.5e15 in EDA. It appears that these new discharges accumulate Mo impurities only up to a point, where an elevated equilibrium level is reached. Further study is probably warranted. Spencer Pitcher

Physics Operator Summaries

Entered: Jul 7 2004 04:36:58:380PM

Author: To Be Determined

Physics operator summary for run 980106. MP 197 -- Helium Probe Edge Measurements & Comparison with Scanning Probe MP 196A -- Reflectometer Calibration SL: Pitcher for MP 197, Lin for MP 196A PO: Granetz Summary: Despite a troublesome morning, we ended up with a very successful run, accomplishing two separate mini-proposals. Physop things learned today: (1) Reducing the slow ZCUR P and D gains from 1.5 to 1.0 after t=0.1 s, or even to 0.7 after t=0.25 s, greatly increases vertical stability in the time range from 0.3 to 0.5 s. A further (but smaller) improvement is achieved by reducing the Ip gain by 20%, although the current feedback control is mildly worsened as well. Thanks goes to Ian for working on this problem. (2) High densities (80% of density limit, and maybe even higher) can be achieved with gas puffing by filling both the J-bottom and K-side plena with 0.2 MPa (30 psi) of D2 and programming both valves (PG 3 and 5) fully open (in addition to nl_04 programming). Shots 2-15 were spent cleaning up the machine after the two week holiday break, and improving early vertical stability (see first comment above). Shots 13-28 were devoted to MP 197. These were very successful shots, with big ramps in the outer gap, at several densities, with and without RF. Weird H-modes were seen on shots 23-26. They had some characteristics of ELM-free and some characteristics of EDA, but with lousy H-factors. Shots 29-34 were devoted to MP 196A. These were also very successful shots, with density ramps up to nebar=4.3e20 m-3 (80% of Greenwald density limit)!! Shot 34 just barely became limited on the outboard limiters for 50 ms (on purpose). ** Warning ** Most of the shots today had large ramps in outer gap and/or density, and therefore are not suitable as starting points for future runs (at least not segment 2). Scorecard: 29 plasmas (7 disrupted early) 4 fizzles 0 duds 1 test ---------- 34 total ------------------------------------------------------------------------------ Run Plan and Engineering Setup for Tuesday, 980106 MP 197 -- Helium Probe Edge Measurements & Comparison with Scanning Probe MP 196A -- Reflectometer Calibration Standard ECDC in deuterium for a couple of hours before run. Engineering setup as on 971218006, with TF under hybrid control This will be 0.8 MA, 5.3 T, nl_04=1e20 m-2, flattop to 1.2 s. Gas setup - fill K-side with 30 PSI of D2, hybrid enable fill B-top with 6 PSI of D2, hybrid enable fill B-side-lower with 1.5 PSI of Ar, hybrid enable Ninja system setup: Fill lower divertor capillary plenum to 5 PSI of helium, and enable the valve. The following gate valves should be enabled for the start of the run, assuming no vacuum problems: ECE (no others until we verify the status of each system) ------ In addition to the two MP's scheduled for today, it has also been requested that we begin with a number of fiducial shots in order to evaluate wall conditions. The setup shot specified above is both a standard 1997 fiducial, as well as the starting point for MP 197. Although MP 197 will begin with ohmic plasmas, later in the morning we will want to have very long 1 MW RF pulses, starting at t=0.4 s and ending at t=1.2 s (RF pulse duration of 0.8 s). The FSP should be setup to scan at t=0.60, 0.85, and 1.10 s on every shot of this MP. Helium will be puffed from the A-B (outboard) limiter midplane during the shots, and the outer gap will be scanned slowly from 15 to 5 mm during each shot. Several densities will be run, with and without RF. MP 196A will be run after MP 197. It requires similar plasma magnetic configurations, but at high density (nebar=4e20 m-3), with no RF. ------------------------------------------------------------------------------- Detailed shot log: Note: BAROLO is dead (hardware problem). Steve W has re-assigned EFIT to run on RHONE, but processes that depend on it will fail. I've sent mail to Tom and Josh, requesting them to re-assign the logical queue name MHDQ. Note: 2 hours of ECDC in deuterium was done prior to today's run. Hybrid coldstart done; no errors found ($set default cmod$models:[hybrid.tcl] $@hybinit_dispatch $@show_bitbus_log Use editor search to verify no occurrences of "error" nor "not respond") Reload fiducial plasma shot 971218006 (0.8 MA, 5.3 T, 1.0e20 m-2) RF on for the initial fiducial shots. RF feedback on RCUR is turned off (RF_LOAD_E = 0.0) Shot 01 -- Standard Tuesday OH test. 10 kA. Coax resistances are good and low. Next shot: try for fiducial plasma. Shot 02 -- Fizzle. Good null. CII level was at 0.01 W/cm2/st. Got the pre-fill gas puff. Next shot: re-try, no changes. Shot 03 -- Fizzle. Good null. CII is lower, but still not down to normal levels. Next shot: gas-head tweak (increase pre-pulse puff from 15 to 18 ms) Shot 04 -- Plasma. Disrupted at 0.43 s. Ip=0.8 MA. VDE. Loop voltage was 2.3 volts! I think it's just dirty. Next shot: repeat, trying to cleanup. Shot 05 -- Fizzle. Next shot: reduce pre-pulse puff from 18 to 14 ms. Shot 06 -- Plasma. Another early VDE disruption. Spencer has noticed that the F-side ratiomatic pressure is 3 times higher than during December, even though the divertor pressure is the same. Next shot: no changes Shot 07 -- Plasma. Another early VDE disruption. Density takes off at 0.34 s, even though the feedback turns off the gas. Spencer is speculating that the plasma is toggling between ohmic H and L modes. Next shot: lower the density from nl04=1.0 to 0.8e20 m-2. Shot 08 -- Plasma. Disrupted even earlier (0.34 s.). There was a large moly brick at 0.26 s. Next shot: repeat, no changes. Shot 09 -- Plasma. Disrupted at 0.46 s. N/Ncrit is reaching 1.2, but the elongation and gaps are not excessive. Next shot: turn off argon Shot 10 -- Plasma. Good shot. Full length. Density was high initially, but got back down to nl04=0.8e20 m-2 after 0.4 s. H-alpha shows continuous dithering for the entire shot. Only difference from the previous shot was turning off the argon. Next shot: reduce early gas valve voltage, and increase nl04 back to 1.0e20 m-2 (from 0.8). Still no argon. Shot 11 -- Plasma, but disrupted early. I think it was due to a moly injection. Early density does not overshoot. Next shot: repeat, no changes. Still no argon. Shot 12 -- Plasma. Good shot. nl04=1.0e20 m-2. Only one RF transmitter worked. Next shot: program RCUR to ramp the outer gap linearly from 15 to 5 mm over the time range of 0.5 to 1.2 s respectively. Also, enable NINJA helium puffing. Shot 13 -- Plasma. Good shot. Outer gap ramped from 15 to 6 mm over the requested time range. No RF. Helium went in. Chromex saturated. FSP needs positioning adjustments. Next shot: increase outer gap ramp by 1 more mm (to get 5 mm instead of 6 mm at end of ramp). Still no argon. Shot 14 -- Plasma, but disrupted early again. Next shot: reduce NINJA plenum pressure from 5 to 3 psi of helium (purge and re-fill). On a suggestion from Ian, reduce slow ZCUR P and D gains from 1.5 to 1.0 (for nearly the entire shot). The claim is that this should help the unstable period around 0.3 s. Also, re-enable argon. Shot 15 -- Fizzle. Null has degraded, but should still be good enough. Next shot: try again, no changes. Shot 16 -- Plasma. Good shot. Outer gap scan is exactly as requested. nl04=1.0e20 m-2. JR saw argon. RF is "practicing" after 1.15 s. Chromex helium data looks pretty good. Vertical instability at t=0.3 s is gone. Next shot: repeat. Turn on fast scanning probe. Shot 17 -- Plasma. Good shot. Good spectrometer data and good scanning probe data. Next shot: reduce density to nl04=0.7e20 m-2 (from 1.0). Also, at Ian's request, further reduce slow ZCUR P and D gains from 1.0 to 0.7 after t=0.25 s. Shot 18 -- Plasma. Good shot. Density only dropped to nl04=0.8e20 m-2 (we wanted 0.7). Also, at Ian's request, reduce RCUR P and D gains from 6 to 5 after t=0.25 s. Next shot: repeat. Increase argon pulse from 12 to 17 ms. Shot 19 -- Plasma. Good shot. Density was still >= 0.8e20 m-2. Next shot: increase density back to nl04=1.0e20 m-2. (Also, change title of segment 2 to "Spencer's outer gap ramp" Shot 20 -- Plasma. Good shot. Got the desired density. Next shot: raise nl04 to 1.5e20 m-2. Still ohmic. Also, at Ian's request, reduce CLEARIN gain by about 20% after t=0.36 s. Shot 21 -- Plasma. Good shot. Density got to nl04=1.3e20 m-2 (wanted 1.5). Scanning probe was turned off. There was a big marfe until 0.5 s. Next shot: same density, ohmic. Undo the CLEARIN gain tweak. The scanning probe will be enabled. Shot 22 -- Plasma. Good shot. nl04=1.3e20 m-2 again. Another big marfe on the upper inboard wall early in the shot. Next shot: repeat, with 1.5 MW of ICRF from t=0.4 to 1.2 s. Also, at Ian's request, reduce Ip gain from 6 to 5 after t=0.41 s. No scanning probe for the next shot. Shot 23 -- Plasma. Good shot. Prf=1.6-1.8 MW for 0.8 s. Plasma is in ELM-free H-mode for the entire RF pulse, with a single ELM at 0.66 s. Density was much higher, nl04=1.8-1.9e20 m-2. Outer gap is now ramping from 13 to 3 mm. 2pi bolo had almost 1 MW of radiation, but it reaches a steady state for 0.5 s, even though it's an ELM-free H-mode. An 0.5 s steady-state ELM-free H-mode! I think that's a new phenomenon. However, the stored energy is only 100 kJ (H factor of 1.2). Next shot: repeat with no changes. Shot 24 -- Plasma. Good shot. Prf=1.6-1.75 MW for 0.8 s. nl04 reaches 2.1e20 m-2. Prad=0.9 MW on 2pi bolo. It looks like an ELM-free H-mode with lousy energy and particle confinement. Next shot: repeat with no changes, except at Ian's request, reduce CLEARIN P gain by 20% after t=1.2 s. Shot 25 -- Plasma. Good shot. Prad was lower. H-alpha was rising slightly as time went by. It's really tough to classify this type of H-mode. Next shot: try for low density (nl04=0.6e20 m-2). Turn down the pre-programmed valve voltage also. Shot 26 -- Plasma. Good shot. Very different looking H-modes. Target density was indeed lower. There are two ELM-free H-modes, followed by two EDA-like H-modes, except that the H-factor is still low. Next shot: repeat one of the earlier high-density shots, but without RF. Re-load 980106023 and turn off RF. Shot 27 -- Plasma. Good shot. nl04=1.3-1.4e20 m-2. Ohmic. No H-modes. Next shot: repeat one of the earlier low-density ohmic shots. Re-load 980106019 (and rename the segment as done for shot 20). Shot 28 -- Plasma. Good shot. nl04=0.8e20 m-2. Good background shot. End of MP 197 (Spencer's run) Start MP 196A (Lin & Irby). Next shot: fill pulse gas 5 plenum (J-bottom) with 30 psi of D2. Reset RCUR demand to give a steady outer gap of about 10 mm. Program in pulse gas 5 voltage to be fully open from t=0.5 to 1.0 s. Program density ramp from nl04=0.6 to 2.4e20 m-2 during the time span of t=0.3 to 1.0 s. Shot 29 -- Plasma. Good shot. Density ramped up to nl04=2.0e20 m-2 at t=1.0 s. Next shot: increase pre-programmed voltage on pulse gas valve 3 to 100 volts from t=0.5 to 1.0 s. Also, turn off argon. Shot 30 -- Plasma. Good shot. Density ramped up to nl04=2.6e20 at t=1.0 s !! All the the shots for this MP will undoubtedly have density-limit disruptions during the rampdown. Outer gap is 12-15 mm. TCI gate valve closes after t=1.2 s, which is why the density looks like it falls quickly. Next shot: reduce outer gap to 5 mm. (Increase RCUR by 4 mm.) Shot 31 -- Plasma. Good shot. Good density ramp. Outer gap is 5-8 mm. Next shot: ramp density to nl04=1.8e20 m-2 at t=0.75 s, then hold density at that value until t=1.0 s. Program the outer gap to scan from 20 to 5 mm during the time span from t=0.75 to 1.0 s. Reduce pre-programmed valve voltages to 50 volts after t=0.75 s. Shot 32 -- Plasma. Good shot. Density flattopped at nl04=1.9e20 m-2 at t=0.75 s. Outer gap ramped from 16 to 7 mm during the time span of t=0.75 to 1.0 s. Next shot: repeat with no changes. Shot 33 -- Plasma. Good shot. Good repeat of the previous shot. Next shot: extend outer gap ramp so that the plasma actually becomes limited on the outboard limiters for 50 ms. Also, extend the density ramp to get a flattop value of nl04=2.1e20 m-2. Shot 34 -- Plasma. Good shot. Density got to nl04=2.3e20 m-2. Plasma just barely became outboard-limited for 50 ms at t=1.0 s. Exactly as requested! All reflectometer channels responded on this shot. End of MP 196A End of run

Session Leader Comments
Jan 6 1998 08:59:37:280AM		Spencer Pitcher	MP 197 Helium Beam Check-Out --------------------------------------- Today we will be comparing the helium beam with the fast-scanning probe (FSP). The helium beam has only sparse spatial coverage, ie 7 mm, and thus to obtain high resolution profiles we will be 'scanning the plasma' by changing the outer gap slowly over 700 ms approx. The FSP will scan at three times, first to ensure the SOL is not evolving during the gap scan, and second, to compare with the helium beam results. The experiment will be performed in Ohmic discharges first and then in RF discharges, a few densities will be used. We also have a piggy-back experiment....Jim Weaver will be trying to make helium II and Halpha drift measurements in the divertor. Contrasting these will shed light on the question of plasma pressure loss in the divertor due to plasma-neutral friction.
Jan 6 1998 05:29:33:100PM		Yijun Lin	MP196a--reflectometer calibration The MP is to produce high density shots to get the calibration of the reflectometer. The main idea is to compare the reflectometer responses to different density ramp and different outer gap. If the phase measurements from all channels are limited at some constants during the varying of the density and the outer gap, it is reasonable to introduce some offsets to calibration the reflectometer. There are four channels of reflectometer working, i.e. 50GHz, 60GHz, 75GHz, and 110GHz channel.
Jan 6 1998 09:48:18:160AM	980106002	Spencer Pitcher	shot 02 - Lower divertor capillary plenum filled to 7 psi of helium (Bob is wrong.)
Jan 6 1998 10:52:55:390AM	980106007	Spencer Pitcher	shot 07 - density rises at .35 s, also fside ratiomatic, Halpha looks like entering dithering Ohmic H-mode. Loop voltage, ie Ohmic power high 1.6 MW. Dithering Ohmic H-mode??? maybe?
Jan 6 1998 11:55:22:840AM	980106012	Spencer Pitcher	next shot - first helium puff thru AB limiter
Jan 6 1998 12:15:18:460PM	980106013	Spencer Pitcher	shot 13 - helium puff thru AB limiter delta_t = 0.1 s starting at 0.15 s @ 7 psia - FSP moving in silo only - Weaver on HeII, Chromex on helium red lines * Weaver computer glitch ... no data * Chromex satruated on 600 line grating
Jan 6 1998 12:24:00:960PM	980106014	Spencer Pitcher	shot 14 - helium puff increased to dt = 0.2 @ 0.15 s - chromex changed to 1200 line grating * plasma disrupts at 0.35 s
Jan 6 1998 12:38:04:290PM	980106015	Spencer Pitcher	shot 15 - ninja plenum changed to 3 psia helium t = .15 s, dt = 0.2 - chromex on 600 line grating * fizzle
Jan 6 1998 12:51:24:780PM	980106016	Spencer Pitcher	shot 16 - ninja t = 0.15 s, dt = .1 s - chromex NOT saturated, although Halpha interference?
Jan 6 1998 01:02:33:920PM	980106017	Spencer Pitcher	shot 17 - FSP to go on this shot - tweak chromex to reduce Halpha interference * good shot, nl4 = 1.0e20, FSP and chromex data both good
Jan 6 1998 01:15:33:560PM	980106018	Spencer Pitcher	shot 18 - drop density, keep all else the same * density not quite flat * fsp and chromex good
Jan 6 1998 01:33:53:420PM	980106019	Spencer Pitcher	shot 19 - repeat from last shot * density behaviour no better....abandon
Jan 6 1998 01:49:17:760PM	980106020	Spencer Pitcher	shot 20 - go back to nl4 = 1.0e20 - shift ninja gas to inner wall (B16-001) for background check * good fsp and chromex data
Jan 6 1998 01:59:07:900PM	980106021	Spencer Pitcher	shot 21 - go to nl4 = 1.5e20 - shift ninja gas to AB limiter again - fsp stays out * upper marfe seen on TV * valves wide open but only got nl4 ~ 1.3e20 * chromex data good
Jan 6 1998 02:14:07:140PM	980106022	Spencer Pitcher	shot 22 - repeat shot 21 - fsp will go * good chromex and fsp data
Jan 6 1998 02:35:01:210PM	980106023	Spencer Pitcher	shot 23 - repeat shot 22 + 1.5 MW ICRH from t = 0.4 to 1.2 s - fsp off * weird shot...starts off ELM-free H-mode with typical signatures. Following a single giant ELM we go into a steady-state ELM-free LOW D-alpha H-mode? or is it enhanced D-alpha H-mode?
Jan 6 1998 02:48:43:440PM	980106024	Spencer Pitcher	shot 24 - repeat of shot 23 - fsp will go - ninja gas shifted to inner wall for background check * good fsp and chromex data * again a new beastie....no large elm this time
Jan 6 1998 03:00:34:340PM	980106025	Spencer Pitcher	shot 25 - repeat of shot 24 - fsp will go - ninja moved to AB limiter * good fsp and chromex data * new beastie again * Halpha rises towards end of shot, no large elm
Jan 6 1998 03:16:50:230PM	980106026	Spencer Pitcher	shot 26 - attempt at lowering density * very messy shot, series of elm-free periods
Jan 6 1998 03:30:12:040PM	980106027	Spencer Pitcher	shot 27 - go back to shot 23, nl4 = 1.5e20, Ohmic, ninja gas to inner wall for background check * chromex and fsp ok
Jan 6 1998 03:39:37:310PM	980106028	Spencer Pitcher	shot 28 - go back to shot 19, nl4 ~ 0.7e20, Ohmic, ninja gas to inner wall for background check * chromex and fsp ok * LAST SHOT OF THIS MINI-PROPOSAL
Jan 6 1998 05:17:04:800PM	980106029	Yijun Lin	shot 29--Density is not as high as expected. Some limitings in the phases are observed. Try higher density next shot.
Jan 6 1998 05:19:42:830PM	980106030	Yijun Lin	shot 30--Density is as high as expected. A good shot to provide refrence data for the following shots.
Jan 6 1998 05:22:34:480PM	980106031	Yijun Lin	shot 31--The outer gap is reduced; however, the preliminary results show there is little variation of the phases in the low frequency channels ( 50 and 60 GHz Channels ) compared with shot 30.
Jan 6 1998 05:24:38:020PM	980106032	Yijun Lin	shot 32--During the ramping of the outer gap, preliminary results show little variation in the phase measure measurement of 50Ghz, 60GHz, and 75 GHz Channels.
Jan 6 1998 05:25:17:360PM	980106033	Yijun Lin	shot 33--Similiar result as last shot.
Jan 6 1998 05:27:59:110PM	980106034	Yijun Lin	shot 34--Similiar preliminary results as last shot even though the ramping of the outer gap is much larger.

Physics Operator Comments
Jan 5 1998 01:11:18:010PM		Robert Granetz	Run Plan for Tuesday, 980106 (con't): In addition to the two MP's scheduled for today, it has also been requested that we begin with a number of fiducial shots in order to evaluate wall conditions. The setup shot specified above is both a standard 1997 fiducial, as well as the starting point for MP 197. Although MP 197 will begin with ohmic plasmas, later in the morning we will want to have very long 1 MW RF pulses, starting at t=0.4 s and ending at t=1.2 s (RF pulse duration of 0.8 s). The FSP should be setup to scan at t=0.60, 0.85, and 1.10 s on every shot of this MP. Helium will be puffed from the A-B (outboard) limiter midplane during the shots, and the outer gap will be scanned slowly from 15 to 5 mm during each shot. Several densities will be run, with and without RF. MP 196A will be run after MP 197. It requires similar plasma magnetic configurations, but at high density (nebar=4e20 m-3), with no RF.
Jan 6 1998 09:03:54:910AM		Robert Granetz	Note: BAROLO is dead (hardware problem). Steve W has re-assigned EFIT to run on RHONE, but processes that depend on it will fail. I've sent mail to Tom and Josh, requesting them to re-assign the logical queue name MHDQ. Note: 2 hours of ECDC in deuterium was done prior to today's run. Hybrid coldstart done; no errors found ($set default cmod$models:[hybrid.tcl] $@hybinit_dispatch $@show_bitbus_log Use editor search to verify no occurrences of "error" nor "not respond") Reload fiducial plasma shot 971218006 (0.8 MA, 5.3 T, 1.0e20 m-2) RF on for the initial fiducial shots. RF feedback on RCUR is turned off (RF_LOAD_E = 0.0)
Jan 6 1998 11:20:17:010AM		Robert Granetz	Run Plan and Engineering Setup for Tuesday, 980106 MP 197 -- Helium Probe Edge Measurements & Comparison with Scanning Probe MP 196A -- Reflectometer Calibration Standard ECDC in deuterium for a couple of hours before run. Engineering setup as on 971218006, with TF under hybrid control This will be 0.8 MA, 5.3 T, nl_04=1e20 m-2, flattop to 1.2 s. Gas setup - fill K-side with 30 PSI of D2, hybrid enable fill B-top with 6 PSI of D2, hybrid enable fill B-side-lower with 1.5 PSI of Ar, hybrid enable Ninja system setup: Fill lower divertor capillary plenum to 5 PSI of helium, and enable the valve. The following gate valves should be enabled for the start of the run, assuming no vacuum problems: ECE (no others until we verify the status of each system)
Jan 6 1998 09:00:09:890AM	980106001	Robert Granetz	Shot 01 -- Standard Tuesday OH test. 10 kA. Coax resistances are good and low. Next shot: try for fiducial plasma.
Jan 6 1998 09:20:59:100AM	980106002	Robert Granetz	Shot 02 -- Fizzle. Good null. CII level was at 0.01 W/cm2/st. Got the pre-fill gas puff. Next shot: re-try, no changes.
Jan 6 1998 09:50:45:410AM	980106003	Robert Granetz	Shot 03 -- Fizzle. Good null. CII is lower, but still not down to normal levels. Next shot: gas-head tweak (increase pre-pulse puff from 15 to 18 ms)
Jan 6 1998 10:01:24:090AM	980106004	Robert Granetz	Shot 04 -- Plasma. Disrupted at 0.43 s. Ip=0.8 MA. VDE. Loop voltage was 2.3 volts! I think it's just dirty. Next shot: repeat, trying to cleanup.
Jan 6 1998 10:09:11:220AM	980106005	Robert Granetz	Shot 05 -- Fizzle. Next shot: reduce pre-pulse puff from 18 to 14 ms.
Jan 6 1998 10:29:52:760AM	980106006	Robert Granetz	Shot 06 -- Plasma. Another early VDE disruption. Spencer has noticed that the F-side ratiomatic pressure is 3 times higher than during December, even though the divertor pressure is the same. Next shot: no changes
Jan 6 1998 10:56:01:690AM	980106007	Robert Granetz	Shot 07 -- Plasma. Another early VDE disruption. Density takes off at 0.34 s, even though the feedback turns off the gas. Spencer is speculating that the plasma is toggling between ohmic H and L modes. Next shot: lower the density from nl04=1.0 to 0.8e20 m-2.
Jan 6 1998 11:00:12:490AM	980106008	Robert Granetz	Shot 08 -- Plasma. Disrupted even earlier (0.34 s.). There was a large moly brick at 0.26 s. Next shot: repeat, no changes.
Jan 6 1998 11:32:15:940AM	980106009	Robert Granetz	Shot 09 -- Plasma. Disrupted at 0.46 s. N/Ncrit is reaching 1.2, but the elongation and gaps are not excessive. Next shot: turn off argon
Jan 6 1998 11:32:52:850AM	980106010	Robert Granetz	Shot 10 -- Plasma. Good shot. Full length. Density was high initially, but got back down to nl04=0.8e20 m-2 after 0.4 s. H-alpha shows continuous dithering for the entire shot. Only difference from the previous shot was turning off the argon. Next shot: reduce early gas valve voltage, and increase nl04 back to 1.0e20 m-2 (from 0.8). Still no argon.
Jan 6 1998 11:43:04:830AM	980106011	Robert Granetz	Shot 11 -- Plasma, but disrupted early. I think it was due to a moly injection. Early density does not overshoot. Next shot: repeat, no changes. Still no argon.
Jan 6 1998 11:58:13:150AM	980106012	Robert Granetz	Shot 12 -- Plasma. Good shot. nl04=1.0e20 m-2. Only one RF transmitter worked. Next shot: program RCUR to ramp the outer gap linearly from 15 to 5 mm over the time range of 0.5 to 1.2 s respectively. Also, enable NINJA helium puffing.
Jan 6 1998 12:13:51:260PM	980106013	Robert Granetz	Shot 13 -- Plasma. Good shot. Outer gap ramped from 15 to 6 mm over the requested time range. No RF. Helium went in. Chromex saturated. FSP needs positioning adjustments. Next shot: increase outer gap ramp by 1 more mm (to get 5 mm instead of 6 mm at end of ramp). Still no argon.
Jan 6 1998 12:23:15:500PM	980106014	Robert Granetz	Shot 14 -- Plasma, but disrupted early again. Next shot: reduce NINJA plenum pressure from 5 to 3 psi of helium (purge and re-fill). On a suggestion from Ian, reduce slow ZCUR P and D gains from 1.5 to 1.0 (for nearly the entire shot). The claim is that this should help the unstable period around 0.3 s. Also, re-enable argon.
Jan 6 1998 12:34:10:480PM	980106015	Robert Granetz	Shot 15 -- Fizzle. Null has degraded, but should still be good enough. Next shot: try again, no changes.
Jan 6 1998 12:50:23:100PM	980106016	Robert Granetz	Shot 16 -- Plasma. Good shot. Outer gap scan is exactly as requested. nl04=1.0e20 m-2. JR saw argon. RF is "practicing" after 1.15 s. Chromex helium data looks pretty good. Vertical instability at t=0.3 s is gone. Next shot: repeat. Turn on fast scanning probe.
Jan 6 1998 01:01:58:670PM	980106017	Robert Granetz	Shot 17 -- Plasma. Good shot. Good spectrometer data and good scanning probe data. Next shot: reduce density to nl04=0.7e20 m-2 (from 1.0). Also, at Ian's request, further reduce slow ZCUR P and D gains from 1.0 to 0.7 after t=0.25 s.
Jan 6 1998 01:15:23:980PM	980106018	Robert Granetz	Shot 18 -- Plasma. Good shot. Density only dropped to nl04=0.8e20 m-2 (we wanted 0.7). Also, at Ian's request, reduce RCUR P and D gains from 6 to 5 after t=0.25 s. Next shot: repeat. Increase argon pulse from 12 to 17 ms.
Jan 6 1998 01:33:16:990PM	980106019	Robert Granetz	Shot 19 -- Plasma. Good shot. Density was still >= 0.8e20 m-2. Next shot: increase density back to nl04=1.0e20 m-2. (Also, change title of segment 2 to "Spencer's outer gap ramp"
Jan 6 1998 01:43:35:860PM	980106020	Robert Granetz	Shot 20 -- Plasma. Good shot. Got the desired density. Next shot: raise nl04 to 1.5e20 m-2. Still ohmic. Also, at Ian's request, reduce CLEARIN gain by about 20% after t=0.36 s.
Jan 6 1998 01:58:55:760PM	980106021	Robert Granetz	Shot 21 -- Plasma. Good shot. Density got to nl04=1.3e20 m-2 (wanted 1.5). Scanning probe was turned off. There was a big marfe until 0.5 s. Next shot: same density, ohmic. Undo the CLEARIN gain tweak. The scanning probe will be enabled.
Jan 6 1998 02:13:30:240PM	980106022	Robert Granetz	Shot 22 -- Plasma. Good shot. nl04=1.3e20 m-2 again. Another big marfe on the upper inboard wall early in the shot. Next shot: repeat, with 1.5 MW of ICRF from t=0.4 to 1.2 s. Also, at Ian's request, reduce Ip gain from 6 to 5 after t=0.41 s. No scanning probe for the next shot.
Jan 6 1998 02:29:30:220PM	980106023	Robert Granetz	Shot 23 -- Plasma. Good shot. Prf=1.6-1.8 MW for 0.8 s. Plasma is in ELM-free H-mode for the entire RF pulse, with a single ELM at 0.66 s. Density was much higher, nl04=1.8-1.9e20 m-2. Outer gap is now ramping from 13 to 3 mm. 2pi bolo had almost 1 MW of radiation, but it reaches a steady state for 0.5 s, even though it's an ELM-free H-mode. An 0.5 s steady-state ELM-free H-mode! I think that's a new phenomenon. However, the stored energy is only 100 kJ (H factor of 1.2). Next shot: repeat with no changes.
Jan 6 1998 02:43:13:850PM	980106024	Robert Granetz	Shot 24 -- Plasma. Good shot. Prf=1.6-1.75 MW for 0.8 s. nl04 reaches 2.1e20 m-2. Prad=0.9 MW on 2pi bolo. It looks like an ELM-free H-mode with lousy energy and particle confinement. Next shot: repeat with no changes, except at Ian's request, reduce CLEARIN P gain by 20% after t=1.2 s.
Jan 6 1998 02:55:19:660PM	980106025	Robert Granetz	Shot 25 -- Plasma. Good shot. Prad was lower. H-alpha was rising slightly as time went by. It's really tough to classify this type of H-mode. Next shot: try for low density (nl04=0.6e20 m-2). Turn down the pre-programmed valve voltage also.
Jan 6 1998 03:13:47:870PM	980106026	Robert Granetz	Shot 26 -- Plasma. Good shot. Very different looking H-modes. Target density was indeed lower. There are two ELM-free H-modes, followed by two EDA-like H-modes, except that the H-factor is still low. Next shot: repeat one of the earlier high-density shots, but without RF. Re-load 980106023 and turn off RF.
Jan 6 1998 03:33:30:280PM	980106027	Robert Granetz	Shot 27 -- Plasma. Good shot. nl04=1.3-1.4e20 m-2. Ohmic. No H-modes. Next shot: repeat one of the earlier low-density ohmic shots. Re-load 980106019 (and rename the segment as done for shot 20).
Jan 6 1998 03:52:57:470PM	980106028	Robert Granetz	Shot 28 -- Plasma. Good shot. nl04=0.8e20 m-2. Good background shot. End of MP 197 (Spencer's run)
Jan 6 1998 03:53:44:430PM	980106029	Robert Granetz	Start MP 196A (Lin & Irby). Next shot: fill pulse gas 5 plenum (J-bottom) with 30 psi of D2. Reset RCUR demand to give a steady outer gap of about 10 mm. Program in pulse gas 5 voltage to be fully open from t=0.5 to 1.0 s. Program density ramp from nl04=0.6 to 2.4e20 m-2 during the time span of t=0.3 to 1.0 s.
Jan 6 1998 04:03:23:220PM	980106029	Robert Granetz	Shot 29 -- Plasma. Good shot. Density ramped up to nl04=2.0e20 m-2 at t=1.0 s. Next shot: increase pre-programmed voltage on pulse gas valve 3 to 100 volts from t=0.5 to 1.0 s. Also, turn off argon.
Jan 6 1998 04:24:48:320PM	980106030	Robert Granetz	Shot 30 -- Plasma. Good shot. Density ramped up to nl04=2.6e20 at t=1.0 s !! All the the shots for this MP will undoubtedly have density-limit disruptions during the rampdown. Outer gap is 12-15 mm. TCI gate valve closes after t=1.2 s, which is why the density looks like it falls quickly. Next shot: reduce outer gap to 5 mm. (Increase RCUR by 4 mm.)
Jan 6 1998 04:44:24:360PM	980106031	Robert Granetz	Shot 31 -- Plasma. Good shot. Good density ramp. Outer gap is 5-8 mm. Next shot: ramp density to nl04=1.8e20 m-2 at t=0.75 s, then hold density at that value until t=1.0 s. Program the outer gap to scan from 20 to 5 mm during the time span from t=0.75 to 1.0 s. Reduce pre-programmed valve voltages to 50 volts after t=0.75 s.
Jan 6 1998 04:48:16:440PM	980106032	Robert Granetz	Shot 32 -- Plasma. Good shot. Density flattopped at nl04=1.9e20 m-2 at t=0.75 s. Outer gap ramped from 16 to 7 mm during the time span of t=0.75 to 1.0 s. Next shot: repeat with no changes.
Jan 6 1998 05:12:56:860PM	980106033	Robert Granetz	Shot 33 -- Plasma. Good shot. Good repeat of the previous shot. Next shot: extend outer gap ramp so that the plasma actually becomes limited on the outboard limiters for 50 ms. Also, extend the density ramp to get a flattop value of nl04=2.1e20 m-2.
Jan 6 1998 05:13:14:850PM	980106034	Robert Granetz	Shot 34 -- Plasma. Good shot. Density got to nl04=2.3e20 m-2. Plasma just barely became outboard-limited for 50 ms at t=1.0 s. Exactly as requested! All reflectometer channels responded on this shot. End of MP 196A End of run

Engineering Operator Comments
Shot	Time	Type	Status	Comment
1	08:48:56:390AM	Test	Ok
2	09:14:46:870AM	Plasma	Ok
3	09:39:23:670AM	Plasma	Bad	fizzle
4	09:52:31:940AM	Plasma	Ok
5	10:03:33:310AM	Plasma	Ok
6	10:15:48:250AM	Plasma	Ok
7	10:31:29:980AM	Plasma	Ok
8	10:52:03:460AM	Plasma	Ok
9	11:03:16:440AM	Plasma	Ok
10	11:17:17:760AM	Plasma	Ok
11	11:34:38:310AM	Plasma	Ok
12	11:44:45:940AM	Plasma	Ok
13	12:00:39:610PM	Plasma	Ok
14	12:14:53:730PM	Plasma	Ok
15	12:27:52:520PM	Plasma	Ok
16	12:37:23:600PM	Plasma	Ok
17	12:51:27:960PM	Plasma	Ok
18	01:04:19:120PM	Plasma	Ok
19	01:20:19:180PM	Plasma	Ok
20	01:36:44:200PM	Plasma	Ok
21	01:50:05:890PM	Plasma	Ok
22	02:04:31:170PM	Plasma	Ok
23	02:15:41:490PM	Plasma	Ok
24	02:32:17:450PM	Plasma	Ok
25	02:45:16:490PM	Plasma	Ok
26	03:03:55:300PM	Plasma	Ok
27	03:18:09:820PM	Plasma	Ok
28	03:33:15:800PM	Plasma	Ok
29	03:55:50:690PM	Plasma	Ok
30	04:10:33:370PM	Plasma	Ok
31	04:25:18:420PM	Plasma	Ok
32	04:40:12:440PM	Plasma	Ok
33	04:52:04:330PM	Plasma	Ok
34	05:02:56:060PM	Plasma	Ok