| Miniproposals | ||||||||||
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| Operators | |
| Session leader(s): | Jim Terry |
| Physics operator(s): | Joseph Snipes |
| Engineering operator(s): | Unknown |
| Engineering Operator Run Comment |
| MP#369 and MP#372 Session Leader: J. Terry, Physics Operator: J. Snipes |
| Session Leader Plans |
| Physics Operators Plans |
| Session Leader Summaries |
| Entered: Jul 7 2004 03:49:02:290PM |
| Author: Jim Terry |
| MP #372 Further Studies of the Quasi-coherent Mode in EDA H-mode Plasmas with piggyback MP #369 Experimental Measurement of Neutral Penetration in H-Mode Plasmas", by J.W. Hughes. Session Leader: J. Terry Physics Operator: J. Snipes The goal of these experiments was to characterize and understand the Quasi-coherent edge fluctuation (QCM) that is believed responsible for the enhanced particle and impurity transport in EDA H-mode discharges. Specifically we will attempt to: 1) Look for the high-frequency (> 1 MHz) companions of the ~100 kHz QCM predicted by the BOUT simulation. 2) Measure the radial extent of the QCM and its scaling with q_95 and height of the density pedestal. 3) Repeat measurements of the scaling of the QCM amplitude with the steady state particle flux into the SOL. 4) Check the effect of flux expansion on the poloidal wavenumber of the QCM by measuring k_pol at various poloidal locations. 5) Measure the relative phase of the QCM as a function of radial position at the outboard midplane. 6) Use the ECE system to look for coherent T_e fluctuations at the location of the QCM. 7) Use innerwall gas puff and innerwall-viewing-fast-diode array to look for the QC mode on the inboard midplane. This was a successful run, accomplishing most of the above goals. A summary of preliminary results with reference to how we did on the above issues follows: 1) The high-frequency (> 1 MHz) companions of the ~100 kHz QCM were NOT found. PCI did observe broadband high frequency fluctuations (1-3 MHz) with a spectrum that changed between EDA and L-mode. (See shot 027) 2) We saw the QCM with radial resolution with both the probe and the fast diode array (FDA). Our attempts to vary the (density) pedestal width by changing q and n_ped were not successful. Edge TS showed that within error there was very little variation in the pedestal width. 3) We were able to change the character and magnitude of the QCM. We have the measurements necessary to calculate the dependence of radial flux with QCM amplitude. Use (Shots 002, 003, 005, 007-009, 014-015, 017, 021, 022, 024-027, and 029.) 4) We have the measurements necessary to determine k_pol for the QCM at the poloidal measurement locations of BES (outboard midplane), the ASP (outboard significantly above the midplane), and the PCI (at the top of the plasma). 5) Using the FDA we can measure the relative phase of the QCM as a function of radial position at the outboard midplane. 6) GPC was set up to look for any Te perturbations associated with the QCM. Although further analysis is required, it is unlikely that we will be able to see the expected perturbation given the signal to noise. (Shots 024-027, and 029 are best for looking.) 7) We looked for the QCM on the inboard side using the fast diode views of the inboard edge. We saw nothing above the noise. We also moved the upper (secondary x-point) far out of the plasma. (Z of the upper x-point was > 59 cm on shots 027 and 029.) It was possible that moving the upper x-point this far away from the primary separatrix might allow the the SOL turbulence (and the QCM) to be larger on the inboard side. However this effect was not seen. No QCM or blobs were seen on the inboard side Shot by shot summary (not completely filled in at the moment): Shot # Ip (MA) QCM timings (s) QCM seen by PCI QCM seen by QCM seen by QCM seen QCM seen Good Da profile outboard FDA Inboard FDA by BES by ASP (Xybion) 001 0.76 0.62-1.22 Not on Ch 14 (no gas puff) No ? No plunge No 002 0.76 0.66-0.82, 0.87-1.22 Yes Ch 13-14 No ? No plunge Yes 003 0.76 0.62-1.22 Yes Ch 13-14 - dithering No ? No plunge Yes 004 0.76 0.66-0.95, 1.04-1.22(weak) Yes Ch 13-14 No ? Yes No 005 0.76 0.64-0.95, 1.04-1.22(weak) Yes No No ? ? Yes 006 0.76 No-power test - 007 0.76 0.63-0.8, 0.83-1.22 Yes Ch 12-14 No ? No Yes 008 0.76 0.64-1.21 No data Ch 11-14 Yes Yes 009 0.76 0.63-0.99 Yes Yes 010 0.76 No EDA No 011 0.76 No EDA, L-mode near n_G No 012 0.76 No EDA No 013 0.76 No EDA Yes 014 0.46 0.62-0.85 Yes(freq width 100-200 kHz)Weak Ch 11-14 Yes, but weak 015 0.46 0.62-0.92, 1.10-1.21 Yes(freq width 100-200 kHz) Yes, but weak 016 0.46 0.66-0.81, 0.99-1.21 Yes(freq width(100-200 kHz)No EDA in window No No No 017 0.46 Yes 018 0.46 No 019 0.46 Fizzle - 020 0.46 No EDA - 021 0.46 Yes 022 0.46 Yes 023 0.46 No EDA - 024 0.98 Yes 025 0.98 Yes 026 0.98 Yes 027 0.98 0.73-0.87, 0.91-1.21 Yes Ch 11-14 No Yes Yes (best) Yes 028 0.98 No EDA - 029 0.98 No laser Ch 11-14 No Yes Yes (best) Yes 030 0.98 No EDA - Proposed Run Plan: We investigate EDA H-modes produced by ICRF heating. To achieve the specific goals listed above we will attempt to: 1) Run plasmas at three different q_{95} values - 3.8 (I_p=1.05 MA, B_T=5.6); 5.0 (I_p=0.75 MA, B_T=5.6); 8.6 (I_p=0.48 MA, B_T=5.6). 2) These different current shots will have differing densities and different RF powers. We expect a range of QCM amplitudes. The key diagnostics are PCI with 10 MHz digitization rate on all channels ASP Gas puff imaging fast diodes - outboard array Gas puff imaging Xybion camera for ``steady-state'' D_alpha radial profiles BES possibly ECE with low pass filter removed reflectometer Edge TS for edge Te and ne Dalsa system The desired shot sequence is as follows: Fill the NINJA plenum with 9 PSI of D2. Puff NINJA from A-B limiter and from inboard midplane. Load shot 1031218016 and modify B_t from 5.4 to 5.6 T, Ip from 0.87 MA to 0.75 MA flattop, the pre-RF target NL-04 from 1.2e20 m^-2 to 0.7e20 m^-2, and hold outer gap at 1.6 cm. The inner gap is 1.0 cm. 1) take 3 shots at B_T=5.6 T, I_p=.75 MA, NL-04 target=7e19, outer gap=1.6 cm, P_RF=2 MW. 2) take 3 shots at B_T=5.6 T, I_p=.75 MA, NL-04 target=1.2e20, outer gap=1.6 cm, P_RF=2.5 MW. 3) take 4 shots at B_T=5.6 T, I_p=.45 MA, NL-04 target=5e19, sweep outer gap from 1.6 to 0.8 cm in 0.1 s after the probe plunge, P_RF=1 MW - insert ASP. These shots are for determinaton of the flux expansion effect on the k_pol and to measure the radial width of the QCM with the probe. 4) take 6 shots at B_T=5.6 T, I_p=.45 MA, NL-04 target=1.0e20, outer gap=1.6 cm, P_RF=2.5 MW. On a shot-by-shot basis move the upper (secondary) x-point as far up and out as possible by controlling RXU and ZXU. Referring to shot 1031219011 it is clear that RXU=-2 cm,ZXU=+4 cm is possible. 5) take 3 shots at B_T=5.6 T, I_p=1.05 MA, NL-04 target=8e19, outer gap=1.6 cm, P_RF=1 MW or minimum for EDA. 6) take 3 shots at B_T=5.6 T, I_p=1.05 MA, NL-04 target=1.5e20, outer gap=1.6 cm, P_RF=2.5 MW. 3 contingency shots for shots that are interesting or are needed repeats. |
| Physics Operator Summaries |
| Entered: Jul 7 2004 04:36:48:660PM |
| Author: Joseph Snipes |
| MP #372 Further Studies of the Quasi-coherent Mode in EDA H-mode Plasmas with piggyback MP #369 Experimental Measurement of Neutral Penetration in H-Mode Plasmas", by J.W. Hughes. Session Leader: J. Terry Physics Operator: J. Snipes Engineering Setup: ECDC overnight in D2 at 2e-4 Torr, stopping by 07:00. Bake at 60 C overnight as well. Run begins at 09:00 and ends at 17:00. Power systems the same as 1031218016 with B_t changed from 5.4 to 5.6 T, Ip from 0.87 MA to 0.75 MA flattop A-coils should be hooked up as on 1031204037 (+Dtop -Dbot -Jtop +Jbot), and the power supply should be enabled. Gas setup: fill B-Top with 6 psi D2 Hybrid enabled (PG4) fill B-side lower with 1 psi Ar Hybrid enabled (PG1) leave B-side upper as is Hybrid DISABLED (PG2) fill C-side with 30 psi D2 Hybrid enabled (PG3) **fill NINJA plenum with 9 psi D2 Enable the following gate valves, assuming no vacuum problems: ECE, VUV, DNB The goal of these experiments is to characterize and understand the Quasi-coherent edge fluctuation (QCM) that is believed responsible for the enhanced particle and impurity transport in EDA H-mode discharges. Specifically we will attempt to: 1) Look for the high-frequency (> 1 MHz) companions of the ~100 kHz QCM predicted by the BOUT simulation. 2) Measure the radial extent of the QCM and its scaling with q_95 and height of the density pedestal. 3) Repeat measurements of the scaling of the QCM amplitude with the steady state particle flux into the SOL. 4) Check the effect of flux expansion on the poloidal wavenumber of the QCM by measuring k_pol at various poloidal locations. 5) Measure the relative phase of the QCM as a function of radial position at the outboard midplane. 6) Use the edge ECE channels to look for coherent T_e fluctuations at the location of the QCM. 7) Use innerwall gas puff and innerwall-viewing-fast-diode array to look for the QC mode on the inboard midplane. We will investigate EDA H-modes produced by ICRF heating. To achieve the specific goals listed above we will: 1) Run plasmas at three different q_{95} values - 3.8 (I_p=1.05 MA, B_T=5.6); 5.0 (I_p=0.75 MA, B_T=5.6); 8.6 (I_p=0.48 MA, B_T=5.6). 2) These different current shots will have differing densities and different RF powers. We expect a range of QCM amplitudes. The key diagnostics are PCI with 10 MHz digitization rate on all channels ASP Gas puff imaging fast diodes - outboard array Gas puff imaging Xybion camera for ``steady-state'' D_alpha radial profiles BES possibly ECE with low pass filter removed reflectometer Edge TS for edge Te and ne Dalsa system The desired shot sequence is as follows: Fill the NINJA plenum with 9 PSI of D2. Puff NINJA from A-B limiter and from inboard midplane. Load shot 1031218016 and modify B_t from 5.4 to 5.6 T, Ip from 0.87 MA to 0.75 MA flattop, the pre-RF target NL-04 from 1.2e20 m^-2 to 0.7e20 m^-2, and hold outer gap at 1.6 cm. The inner gap is 1.0 cm. 1) take 3 shots at B_T=5.6 T, I_p=.75 MA, NL-04 target=7e19, outer gap=1.6 cm, P_RF=2 MW. 2) take 3 shots at B_T=5.6 T, I_p=.75 MA, NL-04 target=1.2e20, outer gap=1.6 cm, P_RF=2.5 MW. 3) take 4 shots at B_T=5.6 T, I_p=.45 MA, NL-04 target=5e19, sweep outer gap from 1.6 to 0.8 cm in 0.1 s after the probe plunge, P_{RF}=1 MW - insert ASP. These shots are for determinaton of the flux expansion effect on the k_pol and to measure the radial width of the QCM with the probe. 4) take 6 shots at B_T=5.6 T, I_p=.45 MA, NL-04 target=1.0e20, outer gap=1.6 cm, P_RF=2.5 MW. On a shot-by-shot basis move the upper (secondary) x-point as far up and out as possible by controlling RXU and ZXU. Referring to shot 1031219011 it is clear that RXU=-2 cm,ZXU=+4 cm is possible. 5) take 3 shots at B_T=5.6 T, I_p=1.05 MA, NL-04 target=8e19, outer gap=1.6 cm, P_RF=1 MW or minimum for EDA. 6) take 3 shots at B_T=5.6 T, I_p=1.05 MA, NL-04 target=1.5e20, outer gap=1.6 cm, P_RF=2.5 MW. 3 contingency shots for shots that are interesting or are needed repeats. Summary: The machine ran very well today. There were 30 shots and 28 full length plasmas. Density feedback failed on one shot causing a high density disruption and the TCI laser failed on two other shots leaving no TCI density data. There were some CAMAC problems on shot 6 so that it was a no power shot. There was one fizzle on shot 19 after which I reduced the Br offset by 0.5 mT to 0 mT and all other shots ran well. Most shots had EDA H-modes and a most of the miniproposal was completed with good QC mode data on a number of fluctuation diagnostics. Shot 1: Copied shot 1031218016 and changed TF current to 156 kA to go to 5.6 T. Reloaded segment 1 from shot 1040115005 to get the startup. Also changed RCUR and CLEARIN to attempt to get a 1.6 cm outer gap and maintain the inner gap constant. Changed nl04 to 7 x 10^19 m^-2. Good shot. Shot 2: Changed RCUR and CLEARIN to attempt to get a constant 1 cm inner gap and 1.6 cm outer gap. Good shot. TF was incorrect in segment 1. Shot 3: Changed TF in segment 1 to 156 kA. Tweaked CLEARIN and RCUR some more to attempt to get constant inner and outer gaps of 1 cm and 1.6 cm, respectively. Good shot. Shot 4: Tweaked CLEARIN and RCUR again to attempt to get the desired gaps. Good shot. Shot 5: Tweaked CLEARIN and RCUR again to attempt to get the desired gaps. Good shot. Shot 6: No power test due to CAMAC problems. Shot 7: Tweaked CLEARIN and RCUR again to attempt to get the desired gaps. Good shot. Shot 8: Increased RCUR by 2.5 mm to reduce the outer gap. Good shot. Shot 9: Repeat. Good shot. RF tripped short H-mode. Shot 10: Increased nl04 to 1.2 x 10^20 m^-2. Good shot. D port failed. No H-mode. Shot 11: Repeat to get more RF. Added 5 ms more Ar for a total of 40 ms duration. Density feedback failed raising nl04 to almost 3 x 10^20 m^-2 before it disrupted at 1.35 s. No RF. Shot 12: Repeat with density feedback and RF. Good shot but RF failed so there was no H-mode. Shot 13: Repeat with RF. Still did not get the RF otherwise a good L-mode. Shot 14: Changed to 0.45 MA, 5 x 10^19 m^-2 and put in a ramp in RCUR from 0.8 to 0.9 s increasing by 4 mm. Good shot. Shot 15: Repeat. Good shot. Shot 16: Repeat. Good shot. Shot 17: Corrected Ip in segment 1 that had been going up toward 0.8 MA to set it back to 0.45 MA as in segment 2. Good shot. Shot 18: Increased nl04 to 1 x 10^20 m^-2 and took out the outer gap scan in RCUR to keep a constant outer gap. Very high density for this current. RF at 2 MW but no H-mode. Shot 19: Reduced nl04 to 8 x 10^19 m^-2. Fizzle! Shot 20: Reduced Br0 by 0.5 mT to 0 mT. Good shot still with a MARFE though. No H-mode. Shot 21: Repeat with more RF to try to get H-mode. Good shot. Got a weak H-mode. Shot 22: Changed RCUR to make it flatter and increase the gap by a couple of mm. Good shot. Shot 23: Reloaded shot 12 to go back to 0.8 MA and 1.2 x 10^20 m^-2. Good shot. No H-mode. Shot 24: Changed Ip to 1 MA, nl04 to 8 x 10^19 m^-2. Good shot. Nice long EDA H-mode from 0.6 - 1.2 s. Shot 25: Reduced RCUR by 1 mm and flattened it to try to reduce the outer gap by 2 mm. Good shot. Two EDA H-modes. Shot 26: Repeat. Good shot. Shot 27: Set RXU to -0.02 and ZXU to +0.04 during the flattop to pull the upper X point up. Good shot. Shot 28: Set ZXU to +0.06 during the flattop to pull the upper X point further up. Good shot but no RF. Shot 29: Repeat with RF. Good shot. Two H-modes. Shot 30: Raise nl04 to 1.3 x 10^20 m^-2. Good shot. TCI laser failed no density data. |
| Session Leader Comments | |||
| Jan 22 2004 09:09:05:113AM | Jim Terry | MP #372 Further Studies of the Quasi-coherent Mode in EDA H-mode Plasmas with piggyback MP #369 Experimental Measurement of Neutral Penetration in H-Mode Plasmas", by J.W. Hughes. Session Leader: J. Terry Physics Operator: J. Snipes The goal of these experiments is to characterize and understand the Quasi-coherent edge fluctuation (QCM) that is believed responsible for the enhanced particle and impurity transport in EDA H-mode discharges. Specifically we will attempt to: 1) Look for the high-frequency (> 1 MHz) companions of the ~100 kHz QCM predicted by the BOUT simulation. 2) Measure the radial extent of the QCM and its scaling with q_95 and height of the density pedestal. 3) Repeat measurements of the scaling of the QCM amplitude with the steady state particle flux into the SOL. 4) Check the effect of flux expansion on the poloidal wavenumber of the QCM by measuring k_pol at various poloidal locations. 5) Measure the relative phase of the QCM as a function of radial position at the outboard midplane. 6) Use the ECE system to look for coherent T_e fluctuations at the location of the QCM. 7) Use innerwall gas puff and innerwall-viewing-fast-diode array to look for the QC mode on the inboard midplane. We will investigate EDA H-modes produced by ICRF heating. To achieve the specific goals listed above we will: 1) Run plasmas at three different q_95 values - 3.8 (I_p=1.05 MA, B_T=5.6); 5.0 (I_p=0.75 MA, B_T=5.6); 8.6 (I_p=0.48 MA, B_T=5.6). 2) These different current shots will have differing densities and different RF powers. We expect a range of QCM amplitudes. The key diagnostics are PCI with 10 MHz digitization rate on all channels ASP Gas puff imaging fast diodes - outboard array Gas puff imaging Xybion camera for ``steady-state'' D_alpha radial profiles BES possibly ECE with low pass filter removed reflectometer Edge TS for edge Te and ne Dalsa system The desired shot sequence is as follows: Fill the NINJA plenum with 9 PSI of D2. Puff NINJA from A-B limiter and from inboard midplane. Load shot 1031218016 and modify B_t from 5.4 to 5.6 T, Ip from 0.87 MA to 0.75 MA flattop, the pre-RF target NL-04 from 1.2e20 m^-2 to 0.7e20 m^-2, and hold outer gap at 1.6 cm. The inner gap is 1.0 cm. Part 1) take 3 shots at B_T=5.6 T, I_p=.75 MA, NL-04 target=7e19, outer gap=1.6 cm, P_RF=2 MW. Part 2) take 3 shots at B_T=5.6 T, I_p=.75 MA, NL-04 target=1.2e20, outer gap=1.6 cm, P_RF=2.5 MW. Part 3) take 4 shots at B_T=5.6 T, I_p=.45 MA, NL-04 target=5e19, sweep outer gap from 1.6 to 0.8 cm in 0.1 s after the probe plunge, P_RF=1 MW - insert ASP. These shots are for determinaton of the flux expansion effect on the k_pol and to measure the radial width of the QCM with the probe. Part 4) take 6 shots at B_T=5.6 T, I_p=.45 MA, NL-04 target=1.0e20, outer gap=1.6 cm, P_RF=2.5 MW. On a shot-by-shot basis move the upper (secondary) x-point as far up and out as possible by controlling RXU and ZXU. Referring to shot 1031219011 it is clear that RXU=-2 cm,ZXU=+4 cm is possible. Part 5) take 3 shots at B_T=5.6 T, I_p=1.05 MA, NL-04 target=8e19, outer gap=1.6 cm, P_RF=1 MW or minimum for EDA. Part 6) take 3 shots at B_T=5.6 T, I_p=1.05 MA, NL-04 target=1.5e20, outer gap=1.6 cm, P_RF=2.5 MW. 3 contingency shots for shots that are interesting or are needed repeats. | |
| Jan 22 2004 10:11:47:050AM | 1040122001 | Jim Terry | Start with Part 1 discharges Good shot - EDA - RF at 2 MW from .6 to 1.2 s, some trips, but stayed in EDA Gaps not quite what we want, Otherwise as desired. Diodes on from 0.935s to 1.066 s NINJA set to puff D2 (437 Torr) at A-B lim and B16-001, but it didn't go for unknown reasons |
| Jan 22 2004 10:10:46:687AM | 1040122002 | Jim Terry | Good shot - EDA, PCI sees QCM for short times, but not during diodes data window Diodes on from 0.935s to 1.066 s NINJA puffed D2 (437 Torr) at A-B lim and B16-001 Innerwall diodes saturate during puff. Outerwall diodes mostly OK |
| Jan 22 2004 10:14:22:097AM | 1040122003 | Jim Terry | Good shot - EDA, PCI sees QCM, but not during diodes data window Diodes on from 0.935s to 1.066 s NINJA puffed D2 (437 Torr) at A-B lim. Outerwall diodes OK. |
| Jan 22 2004 10:15:52:830AM | 1040122004 | Jim Terry | Good shot - EDA, PCI sees QCM, but RF trip drops plasma out of EDA during diodes data window Diodes on from 0.935s to 1.066 s NINJA puffed D2 (437 Torr) at A-B lim. Outerwall diodes OK. |
| Jan 22 2004 10:30:54:307AM | 1040122005 | Jim Terry | Good shot - EDA, PCI sees only a short interval of QCM early, but again an RF trip drops plasma out of EDA during diode data window Diodes on from 0.95s to 1.066 s NINJA puffed D2 (437 Torr) at A-B lim. Outerwall diodes OK. |
| Jan 22 2004 11:18:36:730AM | 1040122007 | Jim Terry | Good shot - EDA - PCI sees QCM, it drops out at 0.8, but returns before the end of the diodes' data window. The drop is due to the ISP insertion. move BES, GPC, and diode data window earlier Diodes moved earlier from 0.8s to 0.916 s NINJA puffed D2 (424 Torr) at A-B lim and innerwall. Outerwall diodes OK. Innerwall 2 and 3 are saturated. |
| Jan 22 2004 11:15:20:057AM | 1040122008 | Jim Terry | Good shot - EDA, PCI, probe, BES, and diodes see QCM Diodes on from 0.8s to 0.916 s NINJA puffed D2 (424 Torr) at A-B lim and innerwall. Outerwall diodes OK. Innerwall 2 and 3 are saturated. |
| Jan 22 2004 11:34:25:457AM | 1040122009 | Jim Terry | Good shot - EDA, PCI, probe, and diodes see QCM No BES Diodes on from 0.8s to 0.916 s NINJA puffed D2 (424 Torr) at A-B lim and innerwall. Outerwall diodes OK. Innerwall 2 and 3 are saturated some of the time, but shoudl see QCM if present. |
| Jan 22 2004 11:41:00:707AM | 1040122010 | Jim Terry | Now move to Part 2), same q_95, but higher density (NL_04-->1.2e20) L-mdoe comparison shot, NO EDA not enough RF power to get H-mode, only 1 MW with many trips Diodes on from 0.8s to 0.916 s NINJA puffed D2 (410 Torr) at A-B lim and innerwall. Outerwall diodes OK. Innerwall 3 is saturated. |
| Jan 22 2004 12:53:23:923PM | 1040122014 | Jim Terry | Move on the Part 3), q_95 to ~9, I_p to 0.45 MA, NL_04 to 0.5e20. with an out gap sweep from 0.8 to 0.9 s RF is better (2MW) - poor EDA until 0.856 s However PCI, probe, and diodes see broad frequency QCM (fo~160 kHz). There is an injection at 0.8 s Diodes on from 0.8s to 0.916 s NINJA puffed D2 (410 Torr) at A-B lim and innerwall. All outer diodes are OK. Innerwall diodes 1,2,3 are saturated some of the time. |
| Jan 22 2004 01:12:31:503PM | 1040122015 | Jim Terry | Repeat the last shot RF is better (2MW) - better EDA lasts until 0.923 s PCI and diodes see broad frequency QCM (f_o~160 kHz). Probe didn't scan, nothing on BES Diodes on from 0.8s to 0.916 s NINJA puffed D2 (390 Torr) at A-B lim and innerwall. All outer diodes are OK. Innerwall diode 2 is saturated most of the time. |
| Jan 22 2004 01:27:32:357PM | 1040122016 | Jim Terry | Repeat the last shot RF is OK (2MW) - a still weak EDA lasts until 0.807 s PCI sees broad frequency QCM (f_o~160 kHz). Because the EDA was lost at 0.807s we got only 7 ms of QCM during diode, BES, diode data window. Diodes on from 0.8s to 0.916 s NINJA puffed D2 (390 Torr) at A-B lim and innerwall. All diodes (inner and outer) are OK. |
| Jan 22 2004 01:41:18:803PM | 1040122017 | Jim Terry | Repeat the last shot RF is OK (2MW) - a still weak EDA lasts until 0.916 s PCI sees broad frequency QCM (f_o~160 kHz). also on diodes and probe. No QCM on BES - outer gap wrong perhaps. Diodes on from 0.8s to 0.931 s NINJA puffed D2 (390 Torr) at A-B lim and innerwall. All diodes (inner and outer) are OK. |
| Jan 22 2004 02:12:21:857PM | 1040122018 | Jim Terry | Now go to Part 4), raise the density (NL_04-->1.0e20), otherwise the same. Because the QCM is so weak, we will not raise the upper X-point scan. RF is OK (2MW) - but no EDA or QCM Diodes on from 0.8s to 0.931 s NINJA puffed D2 (370 Torr) at A-B lim and innerwall. All diodes (inner and outer) are OK. |
| Jan 22 2004 02:12:33:510PM | 1040122019 | Jim Terry | fizzle |
| Jan 22 2004 02:42:07:873PM | 1040122020 | Jim Terry | RF is OK (2MW) - but no EDA or QCM Diodes on from 0.8s to 0.931 s NINJA puffed D2 (370 Torr) at A-B lim and innerwall. All diodes (inner and outer) are OK. |
| Jan 22 2004 02:46:08:700PM | 1040122021 | Jim Terry | Increase the RF power in order to get into EDA. RF is OK (2.5 MW) - weak EDA - QCM seen on PCI and diodes QC frequency width is broad Diodes on from 0.8s to 0.931 s NINJA puffed D2 (419 Torr) at A-B lim and innerwall. All diodes except CSP 14 (saturated some of the time) are OK. |
| Jan 22 2004 02:55:33:387PM | 1040122022 | Jim Terry | Increase the RF power a little more. RF is OK (2.66 MW) - weak EDA - QCM seen on PCI, BES, and outer diodes QC frequency width is broad Diodes on from 0.8s to 0.931 s NINJA puffed D2 (419 Torr) at A-B lim and innerwall. All diodes except CSP 14 (saturated some of the time) are OK. |
| Jan 22 2004 03:13:11:973PM | 1040122023 | Jim Terry | Go back to try and complete Part 2 successfully, since the RF seems to be more reliable. So load shot 1040122012. RF is poor, as in shot 012 - no EDA Diodes on from 0.8s to 0.931 s NINJA puffed D2 (419 Torr) at A-B lim and innerwall. All diodes except CSP 14 and 12 (saturated all of the time) are OK. |
| Jan 22 2004 03:48:09:770PM | 1040122024 | Jim Terry | Move to Part 5 - lower q_95 (=4.2), Ip to 1.0 MA, NL_04 to 8e19. RF is good (1.8 MW) - robust EDA with robust EDA EDA seen on PCI, outer diodes 11-14, BES. Frequency width is narrow, typical of the QCM Diodes on from 0.8s to 0.931 s NINJA puffed D2 (419 Torr) at A-B lim and innerwall. All diodes except IW2 and 3 (saturated most of the time) are OK. |
| Jan 22 2004 03:50:34:130PM | 1040122025 | Jim Terry | RF is good (1.9 MW) - robust EDA with robust EDA EDA seen on PCI, outer diodes 11-14, BES. Frequency width is narrow, typical of the QCM Diodes on from 0.8s to 0.931 s NINJA puffed D2 (400 Torr) at A-B lim and innerwall. All diodes are OK. |
| Jan 22 2004 04:32:28:803PM | 1040122026 | Jim Terry | Repeat RF is good (1.9 MW) - robust EDA with robust EDA EDA seen on PCI, outer diodes 11-14, BES. Frequency width is narrow, typical of the QCM Z_XU is 45 cm R_XU is 51 cm Diodes on from 0.8s to 0.931 s NINJA puffed D2 (400 Torr) at A-B lim and innerwall. All diodes are OK. |
| Jan 22 2004 04:33:45:880PM | 1040122027 | Jim Terry | Repeat, but move upper x-point further up. RF is good (1.9 MW) - robust EDA with robust EDA EDA seen on PCI, outer diodes 11-14, BES. Frequency width is narrow, typical of the QCM Z_XU is 49 cm R_XU is 52 cm Diodes on from 0.8s to 0.931 s NINJA puffed D2 (390 Torr) at A-B lim and innerwall. All diodes are OK. |
| Jan 22 2004 04:49:11:903PM | 1040122028 | Jim Terry | Repeat, but move upper x-point further up. no RF - Da shows some sort of dithering Z_XU is 59 cm R_XU is 50 cm Diodes on from 0.8s to 0.931 s NINJA puffed D2 (390 Torr) at A-B lim and innerwall. All diodes are OK. |
| Jan 22 2004 05:03:28:807PM | 1040122029 | Jim Terry | Repeat Good RF (2.0 MW) - good EDA and QCM Seen on probe and diodes, PCI laser was off. Z_XU big (out of the plasma) Diodes on from 0.8s to 0.931 s NINJA puffed D2 (390 Torr) at A-B lim and innerwall. All diodes are OK. |
| Jan 23 2004 12:44:37:523PM | 1040122030 | Jim Terry | Now move to Part 6), increase the density (NL_04-->1.3e20) keeping everything else the same. Only 1.0 M. This appears to be too low for the transition to EDA. Thus L-mode only, and no QCM Z_XU was big (upper x-point was out of the vessel) Diodes on from 0.8s to 0.931 s NINJA puffed D2 (390 Torr) at A-B lim and innerwall. All diodes are OK. |
| Physics Operator Comments | |||
| Jan 22 2004 08:39:28:290AM | Joseph Snipes | MP #372 Further Studies of the Quasi-coherent Mode in EDA H-mode Plasmas with piggyback MP #369 Experimental Measurement of Neutral Penetration in H-Mode Plasmas", by J.W. Hughes. Session Leader: J. Terry Physics Operator: J. Snipes Engineering Setup: ECDC overnight in D2 at 2e-4 Torr, stopping by 07:00. Bake at 60 C overnight as well. Run begins at 09:00 and ends at 17:00. Power systems the same as 1031218016 with B_t changed from 5.4 to 5.6 T, Ip from 0.87 MA to 0.75 MA flattop A-coils should be hooked up as on 1031204037 (+Dtop -Dbot -Jtop +Jbot), and the power supply should be enabled. Gas setup: fill B-Top with 6 psi D2 Hybrid enabled (PG4) fill B-side lower with 1 psi Ar Hybrid enabled (PG1) leave B-side upper as is Hybrid DISABLED (PG2) fill C-side with 30 psi D2 Hybrid enabled (PG3) **fill NINJA plenum with 9 psi D2 Enable the following gate valves, assuming no vacuum problems: ECE, VUV, DNB The goal of these experiments is to characterize and understand the Quasi-coherent edge fluctuation (QCM) that is believed responsible for the enhanced particle and impurity transport in EDA H-mode discharges. Specifically we will attempt to: 1) Look for the high-frequency (> 1 MHz) companions of the ~100 kHz QCM predicted by the BOUT simulation. 2) Measure the radial extent of the QCM and its scaling with q_95 and height of the density pedestal. 3) Repeat measurements of the scaling of the QCM amplitude with the steady state particle flux into the SOL. 4) Check the effect of flux expansion on the poloidal wavenumber of the QCM by measuring k_pol at various poloidal locations. 5) Measure the relative phase of the QCM as a function of radial position at the outboard midplane. 6) Use the edge ECE channels to look for coherent T_e fluctuations at the location of the QCM. 7) Use innerwall gas puff and innerwall-viewing-fast-diode array to look for the QC mode on the inboard midplane. We will investigate EDA H-modes produced by ICRF heating. To achieve the specific goals listed above we will: 1) Run plasmas at three different q_{95} values - 3.8 (I_p=1.05 MA, B_T=5.6); 5.0 (I_p=0.75 MA, B_T=5.6); 8.6 (I_p=0.48 MA, B_T=5.6). 2) These different current shots will have differing densities and different RF powers. We expect a range of QCM amplitudes. The key diagnostics are PCI with 10 MHz digitization rate on all channels ASP Gas puff imaging fast diodes - outboard array Gas puff imaging Xybion camera for ``steady-state'' D_alpha radial profiles BES possibly ECE with low pass filter removed reflectometer Edge TS for edge Te and ne Dalsa system The desired shot sequence is as follows: Fill the NINJA plenum with 9 PSI of D2. Puff NINJA from A-B limiter and from inboard midplane. Load shot 1031218016 and modify B_t from 5.4 to 5.6 T, Ip from 0.87 MA to 0.75 MA flattop, the pre-RF target NL-04 from 1.2e20 m^-2 to 0.7e20 m^-2, and hold outer gap at 1.6 cm. The inner gap is 1.0 cm. 1) take 3 shots at B_T=5.6 T, I_p=.75 MA, NL-04 target=7e19, outer gap=1.6 cm, P_RF=2 MW. 2) take 3 shots at B_T=5.6 T, I_p=.75 MA, NL-04 target=1.2e20, outer gap=1.6 cm, P_RF=2.5 MW. 3) take 4 shots at B_T=5.6 T, I_p=.45 MA, NL-04 target=5e19, sweep outer gap from 1.6 to 0.8 cm in 0.1 s after the probe plunge, P_{RF}=1 MW - insert ASP. These shots are for determinaton of the flux expansion effect on the k_pol and to measure the radial width of the QCM with the probe. 4) take 6 shots at B_T=5.6 T, I_p=.45 MA, NL-04 target=1.0e20, outer gap=1.6 cm, P_RF=2.5 MW. On a shot-by-shot basis move the upper (secondary) x-point as far up and out as possible by controlling RXU and ZXU. Referring to shot 1031219011 it is clear that RXU=-2 cm,ZXU=+4 cm is possible. 5) take 3 shots at B_T=5.6 T, I_p=1.05 MA, NL-04 target=8e19, outer gap=1.6 cm, P_RF=1 MW or minimum for EDA. 6) take 3 shots at B_T=5.6 T, I_p=1.05 MA, NL-04 target=1.5e20, outer gap=1.6 cm, P_RF=2.5 MW. 3 contingency shots for shots that are interesting or are needed repeats. | |
| Jan 22 2004 09:11:24:320AM | 1040122001 | Joseph Snipes | Shot 1: Copied shot 1031218016 and changed TF current to 156 kA to go to 5.6 T. Reloaded segment 1 from shot 1040115005 to get the startup. Also changed RCUR and CLEARIN to attempt to get a 1.6 cm outer gap and maintain the inner gap constant. Changed nl04 to 7 x 10^19 m^-2. Good shot. |
| Jan 22 2004 09:32:02:517AM | 1040122002 | Joseph Snipes | Shot 2: Changed RCUR and CLEARIN to attempt to get a constant 1 cm inner gap and 1.6 cm outer gap. Good shot. TF was incorrect in segment 1. |
| Jan 22 2004 09:46:55:023AM | 1040122003 | Joseph Snipes | Shot 3: Changed TF in segment 1 to 156 kA. Tweaked CLEARIN and RCUR some more to attempt to get constant inner and outer gaps of 1 cm and 1.6 cm, respectively. Good shot. |
| Jan 22 2004 10:00:29:823AM | 1040122004 | Joseph Snipes | Shot 4: Tweaked CLEARIN and RCUR again to attempt to get the desired gaps. Good shot. |
| Jan 22 2004 10:13:03:563AM | 1040122005 | Joseph Snipes | Shot 5: Tweaked CLEARIN and RCUR again to attempt to get the desired gaps. Good shot. |
| Jan 22 2004 10:51:04:267AM | 1040122006 | Joseph Snipes | Shot 6: Now power test due to CAMAC problems. |
| Jan 22 2004 10:51:37:110AM | 1040122007 | Joseph Snipes | Shot 7: Tweaked CLEARIN and RCUR to attempt to get the desired gaps. Good shot. |
| Jan 22 2004 11:19:26:530AM | 1040122008 | Joseph Snipes | Shot 8: Increased RCUR by 2.5 mm to reduce the outer gap. Good shot. |
| Jan 22 2004 11:24:52:967AM | 1040122009 | Joseph Snipes | Shot 9: Repeat. Good shot. RF tripped short H-mode. |
| Jan 22 2004 11:36:04:533AM | 1040122010 | Joseph Snipes | Shot 10: Increased nl04 to 1.2 x 10^20 m^-2. Good shot. D port failed. No H-mode. |
| Jan 22 2004 11:55:37:197AM | 1040122011 | Joseph Snipes | Shot 11: Repeat to get more RF. Added 5 ms more Ar for a total of 40 ms duration. Density feedback failed raising nl04 to almost 3 x 10^20 m^-2 before it disrupted at 1.35 s. No RF. |
| Jan 22 2004 12:06:45:297PM | 1040122012 | Joseph Snipes | Shot 12: Repeat with density feedback and RF. Good shot but RF failed so there was no H-mode. |
| Jan 22 2004 12:34:04:070PM | 1040122013 | Joseph Snipes | Shot 13: Repeat with RF. Still did not get the RF otherwise a good L-mode. |
| Jan 22 2004 12:36:31:933PM | 1040122014 | Joseph Snipes | Shot 14: Changed to 0.45 MA, 5 x 10^19 m^-2 and put in a ramp in RCUR from 0.8 to 0.9 s increasing by 4 mm. Good shot. |
| Jan 22 2004 12:58:10:503PM | 1040122015 | Joseph Snipes | Shot 15: Repeat. Good shot. |
| Jan 22 2004 01:14:13:317PM | 1040122016 | Joseph Snipes | Shot 16: Repeat. Good shot. |
| Jan 22 2004 01:29:24:827PM | 1040122017 | Joseph Snipes | Shot 17: Corrected Ip in segment 1 that had been going up toward 0.8 MA to set it back to 0.45 MA as in segment 2. Good shot. |
| Jan 22 2004 01:49:31:380PM | 1040122018 | Joseph Snipes | Shot 18: Increased nl04 to 1 x 10^20 m^-2 and took out the outer gap scan in RCUR to keep a constant outer gap. Very high density for this current. RF at 2 MW but no H-mode. |
| Jan 22 2004 01:59:53:313PM | 1040122019 | Joseph Snipes | Shot 19: Reduced nl04 to 8 x 10^19 m^-2. Fizzle! |
| Jan 22 2004 02:20:44:743PM | 1040122020 | Joseph Snipes | Shot 20: Reduced Br0 by 0.5 mT to 0 mT. Good shot still with a MARFE though. No H-mode. |
| Jan 22 2004 02:37:25:363PM | 1040122021 | Joseph Snipes | Shot 21: Repeat with more RF to try to get H-mode. Good shot. Got a weak H-mode. |
| Jan 22 2004 02:48:24:903PM | 1040122022 | Joseph Snipes | Shot 22: Changed RCUR to make it flatter and increase the gap by a couple of mm. Good shot. |
| Jan 22 2004 03:10:03:880PM | 1040122023 | Joseph Snipes | Shot 23: Reloaded shot 12 to go back to 0.8 MA and 1.2 x 10^20 m^-2. Good shot. No H-mode. |
| Jan 22 2004 03:19:41:173PM | 1040122024 | Joseph Snipes | Shot 24: Changed Ip to 1 MA, nl04 to 8 x 10^19 m^-2. Good shot. Nice long EDA H-mode from 0.6 - 1.2 s. |
| Jan 22 2004 03:43:15:540PM | 1040122025 | Joseph Snipes | Shot 25: Reduced RCUR by 1 mm and flattened it to try to reduce the outer gap by 2 mm. Good shot. Two EDA H-modes. |
| Jan 22 2004 04:05:44:530PM | 1040122026 | Joseph Snipes | Shot 26: Repeat. Good shot. |
| Jan 22 2004 04:20:47:557PM | 1040122027 | Joseph Snipes | Shot 27: Set RXU to -0.02 and ZXU to +0.04 during the flattop to pull the upper X point up. Good shot. |
| Jan 22 2004 04:38:36:770PM | 1040122028 | Joseph Snipes | Shot 28: Set ZXU to +0.06 during the flattop to pull the upper X point further up. Good shot but no RF. |
| Jan 22 2004 04:52:24:013PM | 1040122029 | Joseph Snipes | Shot 29: Repeat with RF. Good shot. Two H-modes. |
| Jan 22 2004 05:07:34:913PM | 1040122030 | Joseph Snipes | Shot 30: Raise nl04 to 1.3 x 10^20 m^-2. Good shot. TCI laser failed no density data. |
| Jan 22 2004 05:17:30:347PM | 1040122030 | Joseph Snipes | Summary: The machine ran very well today. There were 30 shots and 28 full length plasmas. Density feedback failed on one shot causing a high density disruption and the TCI laser failed on two other shots leaving no TCI density data. There were some CAMAC problems on shot 6 so that it was a no power shot. There was one fizzle on shot 19 after which I reduced the Br offset by 0.5 mT to 0 mT and all other shots ran well. Most shots had EDA H-modes and a most of the miniproposal was completed with good QC mode data on a number of fluctuation diagnostics. |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 09:08:11:520AM | Plasma | Ok | |
| 2 | 09:27:48:720AM | Plasma | Ok | |
| 3 | 09:44:56:977AM | Plasma | Ok | |
| 4 | 09:58:38:183AM | Plasma | Ok | |
| 5 | 10:11:14:813AM | Plasma | Ok | |
| 7 | 10:42:44:090AM | Plasma | Ok | |
| 8 | 10:59:31:943AM | Plasma | Ok | |
| 9 | 11:17:19:200AM | Plasma | Ok | |
| 10 | 11:32:42:347AM | Plasma | Ok | |
| 11 | 11:46:48:773AM | Plasma | Ok | |
| 12 | 12:02:54:373PM | Plasma | Ok | |
| 13 | 12:17:54:143PM | Plasma | Ok | |
| 14 | 12:34:06:680PM | Plasma | Ok | |
| 15 | 12:53:14:953PM | Plasma | Ok | |
| 16 | 01:12:27:877PM | Plasma | Ok | |
| 17 | 01:26:30:763PM | Plasma | Ok | |
| 18 | 01:42:02:680PM | Plasma | Ok | |
| 19 | 01:57:27:580PM | Plasma | Ok | |
| 20 | 02:13:39:903PM | Plasma | Ok | |
| 21 | 02:29:46:363PM | Plasma | Ok | |
| 22 | 02:45:02:750PM | Plasma | Ok | |
| 23 | 03:01:43:820PM | Plasma | Ok | |
| 24 | 03:16:18:580PM | Plasma | Ok | |
| 25 | 03:39:30:977PM | Plasma | Ok | |
| 26 | 03:53:59:533PM | Plasma | Ok | |
| 27 | 04:17:48:853PM | Plasma | Ok | |
| 28 | 04:32:31:630PM | Plasma | Ok | |
| 29 | 04:49:18:450PM | Plasma | Ok | |
| 30 | 05:02:33:650PM | Plasma | Ok | |