| Miniproposals | ||||||||||
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| Operators | |
| Session leader(s): | John Goetz |
| Physics operator(s): | Joseph Snipes |
| Engineering operator(s): | Vinny Bertolino |
| Engineering Operator Run Comment |
| mp 163 |
| Session Leader Plans |
| Physics Operators Plans |
| Session Leader Summaries |
| Entered: Jul 7 2004 03:49:17:757PM |
| Author: To Be Determined |
| MP #163 High q_parallel Dissipative Divertor This proposal is an attempt to achieve simultaneously a good confinement H-mode with low Zeff and a detached divertor. The goal is to determine the threshold amount of impurity gas necessary to detach the divertor. Also, operation just above and just below the detachment threshold will be investigated. The plan is to: 1. Start with a good shot from 980106, e.g. 980106025, and try to get acceptable H-mode (preferably enhanced D-alpha). Then get the max out of the RF with Ip=1MA, nl04=1.2e20, steady strike points, ... 2. Begin puffing N2 into the H-mode phase to try to detach. Start with 100msec puff of nitrogen from J-bottom, beginning 100msec after the RF. 3. If successful in detaching with high q||, then try setting up feedback on the J-Bottom valve using the divertor bolo signals. 4. Operate just above and just below the detachment threshold and compare the confinement and cleanliness at these levels. 5. Try neon, argon, and krypton Physics Summary: The run was successful in producing enhanced Dalpha (EDA) H-modes. These H-modes were 'steady-state' with H-factors reaching 1.6. The RF boys were able to couple up to 3MW of power. With the radiation levels being low, these plasmas were indeed high q-parallel (greater than 400 GW per square meter). However, when nitrogen was puffed at these plasmas, they objected mightily. The H-modes became ELMfree and impurity accumulation led to the demise of the H-mode. Nitrogen was puffed through a piezo valve located in the divertor and through capillaries in the private flux region. Puffing through a capillary was more benign but still resulted in loss of H-mode, probably because the nitrogen gets to the plasma more slowly. In comparing this run with that of 960227 (the first time detached H-mode was achieved) it is noted that the radiation in the divertor and core plasmas is similar although the H-factor is not as high (1.6 vs. 2.0). The increase in divertor radiation was only about 150kW compared to 500kW (with bad effects on the plasma). It was also noted that the edge pedestals were not very high for a 'good' EDA H-mode. There were some indications of divertor detachment, specifically the temperature at the plate decreases. But, the density at the plate increases leaving constant pressure. Late in the run, attempts were made with nitrogen puffing to detach the Ohmic phase of the discharge. Eventually, the divertor was detached but not without disrupting the plasma. The run ended before a satisfactory puff level could be determined. Thus, the attempt to try and detach an ohmic plasma, reattach it with RF power, and then detach with impurity puffing was not successful (this was an attempt to touch base with previous detachment runs). It is not at all clear as to why these H-mode plasmas would not tolerate any impurity puffing. This awaits further analysis. No attempts to do feedback were tried. However, it is noted that a duty cycle board will be necessary for the J-Bottom piezo valve. It's voltage offset is quite large, ~40V, which could make feedback rather difficult. Shot Result ---- ------ 001 plasma - disrupts @ 0.5 002 plasma - ELMfree H-modes 003 plasma - EDA - strike on the floor 004 plasma - EDA - good shot for 0.8MA 005 plasma - EDA - 1MA - strike point on the floor - corrupted EFIT 006 plasma - EDA - Psol=1.5 007 plasma - EDA - Psol=2MW - H=1.6 008 plasma - EDA - Psol=1.9MW - H=1.6 009 plasma - EDA - one antenna off early - H=1.6 - Psol=2.0MW - 25msec N2 010 plasma - EDA - event @.93 - Psol=1.9MW - H=1.5 - 50msec of N2 @ 0.85sec 011 plasma - EDA - Psol=1.5MW - H=1.4 - 0.7Torr-l of N2 012 plasma - EDA - detachment @ .87?? - H->L @ 0.98 013 plasma - EDA - detachment @ .88?? - H->L @ 1.08 014 plasma - EDA - no detachment - H=1.5 - Psol=2->1.7MW - 0.6 Torr-l of N2 015 plasma - EDA - no detachment - H=1.4 - Psol=1.6MW - 0.7Torr-l of N2 016 plasma - EDA - detachment @ 0.91?? - H=1.4->1.0 - 1.0Torr-l of N2 - Psol=1.9->1.5MW 017 plasma - EDA - detachment @ 0.98?? - H=1.6->1.0 - 1.5torr-l of N2 Psol=1.9->1.2MW 018 plasma - EDA - detachment @ 0.92?? - H=1.5->1.0 - 1.2Torr-l of N2 Psol=1.7->1.0MW - injection @ 0.7sec 019 magnet resistance fault 020 plasma - EDA - no detachment - H=1.5 - 1.2Torr-l of N2 - Prf=2.5MW 021 plasma - no EDA - only one transmitter 022 plasma - no EDA - only one transmitter 023 plasma - EDA from 0.61 to 1.15 - puff through 2 divertor caps 024 plasma - EDA from 0.61 to 0.93 - puff thru 3 divertor caps - H=1.6->1.2 - Psol=2.4->1.6MW 025 plasma - EDA - H=1.6 - Psol=2.2MW 026 plasma - EDA - EFIT troubles 027 magnet resistance fault 028 plasma - EDA until 0.79 - only one transmitter 029 plasma - EDA from 0.93 to 1.2 - delay RF until 0.9sec - 1 capillary of N2 - death ray before RF on 030 plasma - EDA from .93 to 1.14 - 2 caps of N2 - almost detached before RF 031 plasma - 3 caps of N2 - still not detached in the Ohmic phase - the MARFE is back (until 0.5sec) 032 plasma - disrupts @ 0.75 - detachment @ 0.72 033 plasma - disrupts @ 0.74 - detachment @ 0.70 |
| Physics Operator Summaries |
| Entered: Jul 7 2004 04:36:58:410PM |
| Author: To Be Determined |
| MP #163 High q_parallel Dissipative Divertor Session Leader: John Goetz Physics Operator: Joseph Snipes Engineer in Charge: Vincenzo Bertolino Standard ECDC in deuterium for a couple of hours before run. Engineering setup as on 980106025, with TF under hybrid control This will be 0.8 MA, 5.4 T, nl_04=1.5e20 m-2, flattop to 1.2 s. This proposal is an attempt to achieve simultaneously a good confinement H-mode with low Zeff and a detached divertor. The goal is to determine the threshold amount of impurity gas necessary to detach the divertor. Also, operation just above and just below the detachment threshold will be investigated. Short delay in the morning due to an apparent leak in the J-Bottom valve that will be used for nitrogen puffing. Steve Wolfe noted that the shot we copied 980106025 did not have the correct predictors. They are indeed two generations old from a shot before 950112. Overall, it was a very successful run. The machine ran almost perfectly with one early disruption on shot 1, then good shots throughout the day except for two magnet resistance faults. Then, the last two shots disrupted because of excessive nitrogen puffing. On the physics side, EDA H-modes were seen on just about every shot, but it did not require large amounts of nitrogen puffing to make them ELM-free, well before divertor detachment. Clearly, the EDA is very sensitive to impurities. Confinement was not particularly good with H factors around 1.4 to 1.5 but there was nonetheless a large daily dose of neutrons. Shot,Duration(s),Ipmax(MA) Shot,Duration(s),Ipmax 1 0.501 0.823 2 1.583 0.854 3 1.599 0.843 4 1.599 0.843 5 1.570 1.035 6 1.578 1.040 7 1.584 1.029 8 1.576 1.029 9 1.572 1.035 10 1.572 1.029 11 1.574 1.029 12 1.567 1.029 13 1.567 1.035 14 1.566 1.035 15 1.571 1.035 16 1.560 1.029 17 1.571 1.029 18 1.580 1.035 19 0.000 0.005 20 1.569 1.029 21 1.556 1.029 22 1.552 1.029 23 1.477 1.029 24 1.484 1.029 25 1.576 1.029 26 1.502 1.029 27 0.000 0.005 28 1.509 1.029 29 1.480 1.019 30 1.470 1.014 31 1.498 1.014 32 0.755 1.066 33 0.740 1.055 Finished summary for 980107 Total of 33 shots. 33 shots. 31 plasmas. 0 fizzles. 2 faults Shot 1: Copied shot 980106025 but replaced several waveforms from 960227019 to try to get the divertor geometry as in the old shot. Disrupted at 0.5s Shot 2: Tried lowering ZCUR by another cm to reduce the elongation a bit and to get ZMAGX = - 1 cm as desired. Decent shot but with many short ELM-free H-modes. 1.5 MW of RF. ZCUR still higher than what we wanted. Shot 3: Raised ZXL from -0.01 to -0.008 m. Good shot. Fairly long EDA H-mode. Shot 4: Raised ZXL to -0.006 m. Excellent shot. Constant EDA H-mode for more than 0.6 sec. Shot 5: Raised Ip to 1 MA. Good shot. Magnetics TRAQ_1 data corrupted! EFIT not valid after about 0.5 sec. Wolfe will rerun EFIT, but others will have to rerun their automatic routines that depend on EFIT to get correct data. Shot 6: Moved RXL out by 1 cm. Good shot. Shot 7: Moved RXL in by 0.5 cm. Delayed RF until 0.6 sec. Good EDA H-mode. H factors up to 1.6, probably too much Moly. We need to boronize. Shot 8: Repeat. Good shot. Shot 9: Repeat but with short 25 msec N puff from J bottom starting at 0.7 sec. Also disabled Ar puff for a background shot. RF extended to 1.4 sec by mistake. EDA lasts from 0.67 to 1.42 sec. Shot 10: Ar puff re-enabled. N puff set to 50 msec duration. Good shot. Shot 11: N puff moved to 0.85 sec again for 50 msec duration. Ar puff increased from 18 msec to 30 msec duration. Good shot. Shot 12: N puff increased to 100 msec duration. Good shot. EDA goes ELM-free at about 0.9 sec, followed by an H-L transition then a return to EDA H-mode after the N leaves the plasma. Shot 13: ZXL ramp from 0.9 to 1.2 sec from -0.005 to -0.01 m. N puff set to 100 V for 50 msec, then 50 V for 50 msec starting at 0.85 sec. Good shot. Still lost EDA went ELM-free at 0.9 until 1.1 sec, then returned to EDA until 1.2 sec. Shot 14: Reduced N puff to 25 V from 0.9 to 1.0 sec. N valve did not open at 25 V. Good EDA H-mode from 0.67 to 1.22 sec. Shot 15: Increased N puff to 35 V from 0.9 to 1.0 sec. Nice EDA H-mode. Shot 16: Increased N puff to 45 V from 0.9 to 1.0 sec. DAQA crashed causing a short delay. Good shot. EDA goes ELM-free at 0.9 sec then goes in and out of H-mode. Shot 17: Modulated N gas puff 25 msec on and 25 msec off for 4 pulses from 0.85 sec to 1.025 sec. Moved RCUR out 1 mm to 0.667 m to improve RF coupling. EDA drops into ELM-free just before 1 sec then has an H-L transition at 1.1. Shot 18: Modulated N gas puff 20 msec on and 25 msec off for 4 pulses from 0.85 to 1.02 sec. Lowered nl04 from 1.2 x 10^20 to 1 x 10^20 m^-2. Good shot. EDA becomes ELM-free at 0.91 sec, then goes in and out of H-mode. Shot 19: nl04 increased to 1.4 x 10^20 m^-2. Magnet resistance fault. No power supplies fired. Shot 20: Repeat. Good shot. Remained in EDA H-mode from 0.6 to 1.2 sec. Shot 21: Repeat to get higher RF power. Good shot. RF tripped. Shot 22: Repeat to get higher RF power. Good shot. RF tripped. Shot 23: Repeat to get higher RF power. Good shot. RF up to 2.8 MW. NINJA puffing in the divertor starting at 0.62 sec arrives in the plasma around 0.8 sec. Shot 24: Repeat to get higher RF power. Good shot. NINJA puffing at 0.62 sec on this and the previous shot with N. EDA becomes ELM-free around 0.85 sec. Shot 25: No NINJA puff for a baseline. Good shot. RF power up to 3 MW. Steady EDA H-mode from 0.69 to 1.2 sec. Shot 26: NINJA puff at 0.62 sec again. Good shot. Computer problems with EFIT. Shot 27: Repeat due to computer problems with EFIT data on shot 26. Magnet resistance fault. No power supplies. Shot 28: Repeat. Good shot. ELM-free H-modes. D port antenna tripped leaving about 1.5 MW of RF. Shot 29: Delay RF until 0.9 sec to attempt ohmic detachment with N NINJA puff. Good shot. Short H-mode from 0.935 to 1.2 sec. Shot 30: Repeat with 2 NINJA valves open for 100 msec. Good shot. Shot 31: Repeat with 3 NINJA valves. Good shot. Shot 32: Repeat with 3 NINJA valves open for 200 msec. Disrupted at 0.75 sec due to too large a nitrogen puff. Shot 33: Repeat with 150 msec duration on 3 NINJA valves. Disrupted at 0.74 sec. again due to too much nitrogen. |
| Session Leader Comments | |||
| Jan 7 1998 08:28:17:180AM | John Goetz | MP #163 High q_parallel Dissipative Divertor This proposal is an attempt to achieve simultaneously a good confinement H-mode with low Zeff and a detached divertor. The goal is to determine the threshold amount of impurity gas necessary to detach the divertor. Also, operation just above and just below the detachment threshold will be investigated. The plan is to: 1. Start with a good shot from 980106, e.g. 980106025, and try to get acceptable H-mode (preferably enhanced D-alpha). Then get the max out of the RF with Ip=1MA, nl04=1.2e20, steady strike points, ... 2. Begin puffing N2 into the H-mode phase to try to detach. Start with 100msec puff of nitrogen from J-bottom, beginning 100msec after the RF. 3. If successful in detaching with high q||, then try setting up feedback on the J-Bottom valve using the divertor bolo signals. 4. Operate just above and just below the detachment threshold and compare the confinement and cleanliness at these ese levels. 5. Try neon, argon, and krypton | |
| Jan 7 1998 09:15:42:000AM | 980107001 | John Goetz | Shot 980107001 Plasma Disrupts @ 0.5sec due to vertical instability |
| Jan 7 1998 09:36:46:420AM | 980107002 | John Goetz | Shot 980107002 Plasma ELMfree H-modes |
| Jan 7 1998 09:46:56:490AM | 980107003 | John Goetz | Shot 980107003 Plasma EDA H-mode from 0.5 to 1.0sec, but the strike points are on the floor during this time |
| Jan 7 1998 10:01:06:560AM | 980107004 | John Goetz | Shot 980107004 Plasma EDA H-mode from 0.5 to 1.2sec, but the strike points are on the floor until 1.0sec Prf=2.3MW and Psol>2MW |
| Jan 7 1998 10:16:33:400AM | 980107005 | John Goetz | Shot 980107005 Plasma - 1MA EDA H-mode from 0.5 to 1.2sec EFIT convergence troubles so all data reliant on EFIT are suspect |
| Jan 7 1998 10:36:16:420AM | 980107006 | John Goetz | Shot 980107006 Plasma - 1MA EDA H-mode from 0.58 to 1.2sec strike point near probe 5 on the outer plate Prf=2.3MW; Prad=2.3MW; Psol=1.5MW H factor down to 1.3 at the end of the shot |
| Jan 7 1998 10:48:40:850AM | 980107007 | John Goetz | Shot 980107007 Plasma RF turn-on @ 0.6sec to allow for higher initial density EDA H-mode from 0.68 to 1.24sec strike point near probe 4 on the outer plate; very good target plasma Prf=2.3MW; Prad=1.4MW; Psol=2.0MW; H factor = 1.6 |
| Jan 7 1998 10:58:19:530AM | 980107008 | John Goetz | Shot 980107008 Plasma EDA H-mode from 0.66 to 1.24sec strike point between probe 3 and 4 on the outer plate; very good target plasma Prf=2.3MW; Prad=1.4MW; Psol=1.9MW; H factor = 1.6 |
| Jan 7 1998 11:16:31:670AM | 980107009 | John Goetz | Shot 980107009 Plasma EDA H-mode from 0.66 to 1.24sec; but one antenna off @ 0.95 strike point between probe 3 and 4 on the outer plate; very good target plasma Prf=2.2MW; Prad=1.3MW; Psol=2.0MW; H factor = 1.6 25msec of N2 puffed |
| Jan 7 1998 11:31:16:100AM | 980107010 | John Goetz | Shot 980107010 Plasma EDA H-mode from 0.66 to 1.24sec event at 0.93sec; density up, Prad up; W down Prf=2.2MW; Prad=1.4MW; Psol=1.9MW; H factor = 1.5 50msec of N2 puffed @ 0.7sec |
| Jan 7 1998 12:14:19:920PM | 980107012 | John Goetz | Shot 980107012 Plasma EDA H-mode from 0.68 to 0.98sec H -> L transition detachment @ 0.87 Prf=2.2MW; Prad=1.6->2.4MW; Psol=1.9->1.3MW; H factor = 1.5->1.3 100msec of N2 puffed @ 0.85sec [1.6 Torr-l] |
| Jan 7 1998 12:20:52:690PM | 980107013 | John Goetz | Shot 980107013 Plasma EDA H-mode from 0.68 to 1.08sec followed by an H -> L transition detachment @ 0.88?? Prf=2.15MW; Prad=1.5->2.5MW; Psol=2.0->1.4MW; H factor = 1.5->1.35 0.9 Torr-l of N2 puffed @ 0.85sec |
| Jan 7 1998 12:31:04:370PM | 980107014 | John Goetz | Shot 980107014 Plasma EDA H-mode from 0.68 to 1.2 no signs of detachment Prf=2.4MW; Prad=1.9MW; Psol=2.0->1.7MW; H factor = 1.5 0.6 Torr-l of N2 puffed @ 0.85sec |
| Jan 7 1998 12:45:03:020PM | 980107015 | John Goetz | Shot 980107015 Plasma EDA H-mode from 0.67 to 1.24 no signs of detachment Prf=2.4MW; Prad=2.0MW; Psol=1.6MW; H factor = 1.4 0.7 Torr-l of N2 puffed @ 0.85sec |
| Jan 7 1998 01:30:34:020PM | 980107016 | John Goetz | Shot 980107016 Plasma EDA H-mode from 0.67 to 0.95; H->L transition detachment @ 0.91?? divertor temperature drops but density goes up Prf=2.2MW; Prad=1.8->2.3MW; Psol=1.9->1.5MW; H factor = 1.4 -> 1.0 1.0 Torr-l of N2 puffed @ 0.85sec |
| Jan 7 1998 01:36:26:490PM | 980107017 | John Goetz | Shot 980107017 Plasma EDA H-mode from 0.67 to 1.08; H->L transition detachment @ 0.97?? divertor temperature drops but density goes up deuterium light decreases more slowly, somewhat like 960227019 Prf=2.4MW; Prad=1.5->2.5MW; Psol=1.9->1.2MW; H factor = 1.6 -> 1.0 1.5 Torr-l of N2 puffed @ 0.85sec |
| Jan 7 1998 01:52:25:950PM | 980107018 | John Goetz | Shot 980107018 Plasma - lower target density than 017 EDA H-mode from 0.63 to 0.93; H->L transition detachment @ 0.92?? very quick to L-mode after this some injection @ 0.7sec Prf=2.2MW; Prad=2.3MW; Psol=1.7->1.0MW; H factor = 1.5 -> 1.0 1.2 Torr-l of N2 puffed @ 0.85sec |
| Jan 7 1998 02:13:44:120PM | 980107020 | John Goetz | Shot 980107020 Plasma - higher target density than 018 EDA H-mode from 0.62 to 1.23 no detachment Prf=2.5MW; Prad=1.5->1.9->1.6MW; Psol=2.3->1.7MW; H factor = 1.5 |-this is due to nitrogen puff 1.2 Torr-l of N2 puffed @ 0.85sec |
| Jan 7 1998 02:24:30:760PM | 980107021 | John Goetz | Shot 980107021 Plasma no EDA H-mode - only one RF transmitter was operating |
| Jan 7 1998 02:40:57:510PM | 980107022 | John Goetz | Shot 980107022 Plasma no EDA H-mode - only one RF transmitter was operating |
| Jan 7 1998 03:03:26:970PM | 980107023 | John Goetz | Shot 980107023 Plasma EDA H-mode from 0.63 to 1.15 injection @ 1.05 - H->L transition at 1.16 two capillary valves puffed with 11psi nitrogen Prf=2.8MW - Prad=1.7MW - Psol=2.4->2.0MW with N2 injection H=1.6 |
| Jan 7 1998 03:12:01:200PM | 980107024 | John Goetz | Shot 980107024 Plasma EDA H-mode from 0.61 to 0.93 - RF trip three capillary valves puffed with 11psi nitrogen Prf=2.8MW - Prad=1.3->2.7MW - Psol=2.4->2.0MW with N2 injection H=1.6->1.2 |
| Jan 7 1998 03:28:10:240PM | 980107025 | John Goetz | Shot 980107025 Plasma EDA H-mode from .62 to 1.2 baseline - no nitrogen puffed Prf=3.0MW - Prad=1.7MW - Psol=2.2MW H=1.6; W=0.175MJ |
| Jan 7 1998 03:45:17:740PM | 980107026 | John Goetz | Shot 980107026 Plasma EDA H-mode from .62 to 1.0 three capillaries of nitrogen puffed EFIT troubles |
| Jan 7 1998 03:58:18:400PM | 980107028 | John Goetz | Shot 980107028 Plasma EDA from 0.63 to 0.79sec only one transmitter |
| Jan 7 1998 04:17:27:990PM | 980107029 | John Goetz | Shot 980107029 Plasma EDA from 0.9 to 1.2sec - RF delayed until 0.9sec puff 1 capillary of nitrogen check for detachment - probably a death ray before the RF turns on |
| Jan 7 1998 04:28:52:640PM | 980107030 | John Goetz | Shot 980107030 Plasma EDA from 0.93 to 1.14sec - RF trip - H->L transition puff 2 capillary of nitrogen closer to detachment than 029 - probably a death ray before the RF turns on |
| Jan 7 1998 04:44:11:710PM | 980107031 | John Goetz | Shot 980107031 Plasma EDA from 0.93 to 1.17sec puff 3 capillaries of nitrogen still not detached in the Ohmic phase |
| Jan 7 1998 04:58:46:000PM | 980107032 | John Goetz | Shot 980107032 Plasma disrupts @ 0.75 divertor detaches 0.72 - too much nitrogen |
| Jan 7 1998 05:10:46:000PM | 980107033 | John Goetz | Shot 980107033 Plasma disrupts @ 0.74 divertor detaches 0.7 - too much nitrogen |
| Physics Operator Comments | |||
| Jan 7 1998 09:16:09:280AM | 980107001 | Joseph Snipes | Session Leader: John Goetz Physics Operator: Joseph Snipes Engineer in Charge: Vincenzo Bertolino Standard ECDC in deuterium for a couple of hours before run. Engineering setup as on 980106025, with TF under hybrid control This will be 0.8 MA, 5.4 T, nl_04=1.5e20 m-2, flattop to 1.2 s. This proposal is an attempt to achieve simultaneously a good confinement H-mode with low Zeff and a detached divertor. The goal is to determine the threshold amount of impurity gas necessary to detach the divertor. Also, operation just above and just below the detachment threshold will be investigated. |
| Jan 7 1998 09:16:35:650AM | 980107001 | Joseph Snipes | Short delay in the morning due to an apparent leak in the J-Bottom valve that will be used for nitrogen puffing. Shot 1: Copied shot 980106025 but replaced several waveforms from 960227019 to try to get the divertor geometry as in the old shot. Disrupted at 0.5s |
| Jan 7 1998 09:36:35:400AM | 980107002 | Joseph Snipes | Shot 2: Tried lowering ZCUR by another cm to reduce the elongation a bit and to get ZMAGX = - 1 cm as desired. Decent shot but with many short ELM-free H-modes. 1.5 MW of RF. ZCUR still higher than what we wanted. |
| Jan 7 1998 09:40:01:870AM | 980107003 | Joseph Snipes | Shot 3: Raised ZXL from -0.01 to -0.008 m. Good shot. Fairly long EDA H-mode. |
| Jan 7 1998 10:02:34:650AM | 980107004 | Joseph Snipes | Shot 4: Raised ZXL to -0.006 m. Excellent shot. Constant EDA H-mode for more than 0.6 sec. |
| Jan 7 1998 10:08:28:780AM | 980107005 | Joseph Snipes | Shot 5: Raised Ip to 1 MA. Good shot. Magnetics TRAQ_1 data corrupted! |
| Jan 7 1998 10:19:34:780AM | 980107005 | Joseph Snipes | Shot 5: Raised Ip to 1 MA. Good shot. Magnetics TRAQ_1 data corrupted! EFIT not valid after about 0.5 sec. |
| Jan 7 1998 10:25:54:150AM | 980107006 | Joseph Snipes | Shot 6: Moved RXL out by 1 cm. Good shot. |
| Jan 7 1998 10:43:22:790AM | 980107007 | Joseph Snipes | Shot 7: Moved RXL in by 0.5 cm. Delayed RF until 0.6 sec. Good EDA H-mode. |
| Jan 7 1998 10:56:24:260AM | 980107008 | Joseph Snipes | Shot 8: Repeat. Good shot. |
| Jan 7 1998 11:09:54:800AM | 980107009 | Joseph Snipes | Shot 9: Repeat but with short 25 msec N puff from J bottom starting at 0.7 sec. Also disabled Ar puff for a background shot. RF extended to 1.4 sec by mistake. EDA lasts from 0.67 to 1.42 sec. |
| Jan 7 1998 11:23:17:100AM | 980107010 | Joseph Snipes | Shot 10: Ar puff re-enabled. N puff set to 50 msec duration. Good shot. |
| Jan 7 1998 11:41:30:710AM | 980107011 | Joseph Snipes | Shot 11: N puff moved to 0.85 sec again for 50 msec duration. Ar puff increased from 18 msec to 30 msec duration. Good shot. |
| Jan 7 1998 11:50:19:800AM | 980107012 | Joseph Snipes | Shot 12: N puff increased to 100 msec duration. Good shot. EDA goes ELM-free at about 0.9 sec, followed by an H-L transition then a return to EDA H-mode. |
| Jan 7 1998 12:09:54:150PM | 980107013 | Joseph Snipes | Shot 13: ZXL ramp from 0.9 to 1.2 sec from -0.005 to -0.01 m. N puff set to 100 V for 50 msec, then 50 V for 50 msec starting at 0.85 sec. Good shot. |
| Jan 7 1998 12:27:18:940PM | 980107014 | Joseph Snipes | Shot 14: Reduced N puff to 25 V from 0.9 to 1.0 sec. N valve did not open at 25 V. Good EDA H-mode from 0.67 to 1.22 sec. |
| Jan 7 1998 12:39:01:690PM | 980107015 | Joseph Snipes | Shot 15: Increased N puff to 35 V from 0.9 to 1.0 sec. Nice EDA H-mode. |
| Jan 7 1998 01:22:18:760PM | 980107016 | Joseph Snipes | Shot 16: Increased N puff to 45 V from 0.9 to 1.0 sec. DAQA crashed causing a short delay. Good shot. EDA goes ELM-free at 0.9 sec then goes in and out of H-mode. |
| Jan 7 1998 01:34:26:300PM | 980107017 | Joseph Snipes | Shot 17: Modulated N gas puff 25 msec on and 25 msec off for 4 pulses from 0.85 sec to 1.025 sec. Moved RCUR out 1 mm to 0.667 m to improve RF coupling. EDA drops into ELM-free just before 1 sec then has an H-L transition at 1.1. |
| Jan 7 1998 01:55:23:650PM | 980107018 | Joseph Snipes | Shot 18: Modulated N gas puff 20 msec on and 25 msec off for 4 pulses from 0.85 to 1.02 sec. Lowered nl04 from 1.2 x 10^20 to 1 x 10^20 m^-2. Good shot. EDA becomes ELM-free at 0.91 sec, then goes in and out of H-mode. |
| Jan 7 1998 01:55:49:530PM | 980107019 | Joseph Snipes | Shot 19: nl04 increased to 1.4 x 10^20 m^-2. Magnet resistance fault. No power supplies fired. |
| Jan 7 1998 02:11:42:960PM | 980107020 | Joseph Snipes | Shot 20: Repeat. Good shot. Remained in EDA H-mode from 0.6 to 1.2 sec. |
| Jan 7 1998 02:30:10:790PM | 980107021 | Joseph Snipes | Shot 21: Repeat to get higher RF power. Good shot. RF tripped. |
| Jan 7 1998 03:02:42:770PM | 980107022 | Joseph Snipes | Shot 22: Repeat to get higher RF power. Good shot. RF tripped. |
| Jan 7 1998 03:03:03:770PM | 980107023 | Joseph Snipes | Shot 23: Repeat to get higher RF power. Good shot. RF up to 2.8 MW |
| Jan 7 1998 03:20:52:800PM | 980107024 | Joseph Snipes | Shot 24: Repeat to get higher RF power. Good shot. NINJA puffing at 0.62 sec on this and the previous shot with N. EDA becomes ELM-free around 0.85 sec. |
| Jan 7 1998 03:21:14:020PM | 980107025 | Joseph Snipes | Shot 25: No NINJA puff for a baseline. Good shot. RF power up to 3 MW. Steady EDA H-mode from 0.69 to 1.2 sec. |
| Jan 7 1998 03:44:38:160PM | 980107026 | Joseph Snipes | Shot 26: NINJA puff at 0.62 sec again. Computer problems with EFIT. |
| Jan 7 1998 03:59:52:440PM | 980107027 | Joseph Snipes | Shot 27: Repeat due to computer problems with EFIT data on shot 26. Magnet resistance fault. No power supplies. |
| Jan 7 1998 04:00:17:920PM | 980107028 | Joseph Snipes | Shot 28: Repeat. Good shot. ELM-free H-modes. D port antenna tripped leaving about 1.5 MW of RF. |
| Jan 7 1998 04:30:39:090PM | 980107029 | Joseph Snipes | Shot 29: Delay RF until 0.9 sec to attempt ohmic detachment with N NINJA puff. Good shot. Short H-mode from 0.935 to 1.2 sec. |
| Jan 7 1998 04:36:43:980PM | 980107030 | Joseph Snipes | Shot 30: Repeat with 2 NINJA valves. Good shot. |
| Jan 7 1998 04:54:47:590PM | 980107031 | Joseph Snipes | Shot 31: Repeat with 3 NINJA valves. Good shot. |
| Jan 7 1998 05:02:41:850PM | 980107032 | Joseph Snipes | Shot 32: Repeat with 3 NINJA valves open for 200 msec. Disrupted at 0.75 sec. due to too large a nitrogen puff. |
| Jan 7 1998 05:04:15:210PM | 980107033 | Joseph Snipes | Shot 33: Repeat with 150 msec duration on 3 NINJA valves. Disrupted at 0.74 sec. again due to too much nitrogen. |
| Jan 7 1998 05:20:24:770PM | 980107033 | Joseph Snipes | Overall, it was a very successful run. The machine ran almost perfectly with one early disruption on shot 1, then good shots throughout the day except for two magnet resistance faults. Then, the last two shots disrupted because of excessive nitrogen puffing. On the physics side, EDA H-modes were seen on just about every shot, but it did not require large amounts of nitrogen puffing to make them ELM-free, well before divertor detachment. Clearly, the EDA is very sensitive to impurities. Confinement was not particularly good with H factors around 1.4 to 1.5 but there was nonetheless a large daily dose of neutrons. |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 08:58:06:210AM | Plasma | Ok | no faults plasma |
| 2 | 09:18:01:860AM | Plasma | Ok | |
| 3 | 09:33:30:090AM | Plasma | Ok | |
| 4 | 09:47:54:060AM | Plasma | Ok | |
| 5 | 10:00:45:020AM | Plasma | Ok | |
| 6 | 10:18:57:970AM | Plasma | Ok | |
| 7 | 10:34:42:860AM | Plasma | Ok | |
| 8 | 10:48:23:880AM | Plasma | Ok | |
| 9 | 11:03:01:490AM | Plasma | Ok | |
| 10 | 11:16:23:660AM | Plasma | Ok | |
| 11 | 11:29:36:730AM | Plasma | Ok | |
| 12 | 11:44:45:130AM | Plasma | Ok | |
| 13 | 12:01:54:100PM | Plasma | Ok | |
| 14 | 12:16:15:030PM | Plasma | Ok | |
| 15 | 12:30:51:600PM | Plasma | Ok | |
| 16 | 01:05:43:530PM | Plasma | Ok | |
| 17 | 01:24:26:130PM | Plasma | Ok | |
| 18 | 01:39:18:640PM | Plasma | Ok | |
| 19 | 01:51:58:480PM | Plasma | Bad | mag res. flt |
| 20 | 02:01:35:800PM | Plasma | Ok | |
| 21 | 02:19:04:690PM | Plasma | Ok | |
| 22 | 02:30:52:450PM | Plasma | Ok | |
| 23 | 02:44:07:600PM | Plasma | Ok | |
| 24 | 03:00:13:300PM | Plasma | Ok | |
| 25 | 03:13:22:840PM | Plasma | Ok | |
| 26 | 03:27:30:000PM | Plasma | Ok | |
| 27 | 03:44:44:160PM | Plasma | Bad | mag res flt |
| 28 | 03:53:56:900PM | Plasma | Ok | |
| 29 | 04:06:03:680PM | Plasma | Ok | |
| 30 | 04:18:54:080PM | Plasma | Ok | |
| 31 | 04:34:17:540PM | Plasma | Ok | |
| 32 | 04:47:49:280PM | Plasma | Ok | |
| 33 | 04:59:24:800PM | Plasma | Ok | |