| Miniproposals | ||||||||||||
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| Operators | |
| Session leader(s): | Basil Duval,Alex Ince-Cushman,Alex Ince-Cushman |
| Physics operator(s): | Jim Irby |
| Engineering operator(s): | Bill Parkin,Bill Cochran |
| Engineering Operator Run Comment |
| am: MP535a Rotation inversion in improved L-mode pm: MP550 Momentum tran |
| Session Leader Plans |
| Entered: May 1 2008 01:04:05:947PM |
| Author: Yijun Lin |
| SL-plan: 1080502, 17:00 pm - 18:00 pm
MP 378, MC flow study with J-antenna at 50 MHz. shots 1. Reload shot 1080422026, USN, 800 kA shot. 5.1 Tesla. No He3-puff. Need Argon puff. Run J 2 MW flat, then D+E steps to 2.5 MW. Check rotation and impurity temperature. 2. Run J, 4 steps to 3 MW, 50 ms He3 puff starting at 0.2 sec, counter-cd phase. 3. Run J, 4 steps to 3 MW, 150 ms He3 puff. counter-cd phase. 4. To be determined. (May repeat 3, with co-cd phase, or with 200 ms He3 puff). 5. To be determined. |
| Physics Operators Plans |
| Entered: May 2 2008 08:34:48:600AM |
| Author: Jim Irby |
| -----------------
Engineering Setup ----------------- Run begins at 09:00 and ends at 18:00 (one extra hour) Power systems as on: am: MP535a Rotation inversion in improved L-mode load shot 1080215001 --- locked mode fiducial shot pm: MP550 Momentum transport w/A-coil locking load shots 1080215001 and 1080130025 17:00-18:00: Y. Lin load shot 1080422026 He3 injection from B-side upper Acoil: +Dtop -Dbot -Jtop +Jbot (standard) Hybrid Enabled Gas setup: Fill B-Top with 6 psi D2 Hybrid enabled (PG4) fill B-side lower with 1 psi Ar Hybrid DISABLED (PG1) leave B-side upper as is Hybrid DISABLED (PG2) fill B-main (C-side) with 40 psi D2 Hybrid enabled (PG3) fill NINJA with 10 psi D2 DISABLED Special gas: Helium-3, B-upper, 15 PSI --- at end of run Enable gatevalves and shutters: ECE, VUV, DNB, Z-bolo Torvac gatevalve toggle (yes/no): no Boronization(yes/no): no Overnight ECDC (yes/no): yes ICRF(yes/no): yes LH(yes/no): no DNB(yes/no): yes Cryopump (yes/no): no Overnight vessel temperature: 60/60/60 ------------------------------ ECDC Parameters ------------------------------ gas and pressure: D2 at 2e-4 Torr sweep: 44/45/103 cm scan: 20/120 s |
| Session Leader Summaries |
| Entered: May 2 2008 05:34:02:230PM |
| Author: John Rice |
| Session Leader Run Summary for 1080502 MP535a Rotation Inversion vs Density and Current, in Limited and Diverted L-mode Plasmas
The first 2 shots were devoted to obtaining locked modes, for wavelength calibrations for HIREX-Sr. Shots 4-9 were spent performing a density scan in LSN discharges with current around 0.65 MA, magnetic field of 3.0 T and q95 of 3. For a range of average densities between .35 and 0.7 10^20/m^3, and no rotation inversion was found. For shots 10-16, limited discharges were run, and good rotation inversions were found on 14 and 15, where the average density was around .7. For higher and lower densities, no inversion was seen. For shots 14 and 15, the rotation inversion occured inside of R=0.82 m only, and seem qualitatively similar to the TCV results. After 12:30, there were no further shots, due to a variety of problems. |
| Physics Operator Summaries |
| Entered: May 2 2008 06:40:38:093PM |
| Author: Jim Irby |
| Until we had a problem with the OH2U commutation system and then the
data system we were doing extremely well today. We began with 1080215001, the locked mode fiducial for calibration of the rotation diagnostics. Then we started mp53a to study rotation reversal in l-mode plasmas by loading 1080430002, adjusted for 3 rather than 3.3T. After several shots with variations of Ip and density, we went limited on shot 1080502010, to stay out of h-mode. SL generally got what he wanted except for a density ramp shot that fizzled because of the OH2U commutation problem. Unfortunately we were unable to get any data for Alex and Yijun today. After about 13:00 things went south with data and power system problem. Even the PEI air switch did us in on shot 25, after which we gave up. ----------------------------------------------- problems: Oh2u did not commutate on shot 017. PFN current only 20 kA. Blown fuses were found and replaced. Oh2s misbehaved on shot 023 producing a fizzle. Currents go awry from -1.1 s on both oh2u and oh2l. On shot 024 we had a forced invert because of a type II fault generated by an I^2t from ef1u. Still had same oh problem we had on 023. On shot 025 PEI air would not open. shot 19 does not exist ------------------------------------------------ Score: power system troubles 017,023,024,25 no power 018,020,21,22 plasma 01,02,03,04,05,06,07,08,09,10 11,12,13,14,15,16 |
| Session Leader Comments | |||
| May 2 2008 12:45:29:793PM | 1080502004 | Basil Duval | Pre: Locked mode reference for Vphi=0
Post: OK |
| May 2 2008 12:47:35:937PM | 1080502005 | Basil Duval | Pre: Lower Ne-
Post: OK, qe ~3.2 small H-mode later (apparently normal at lower Bphi and Ip) Note: Since breakdown is at 5T, it takes until ~0.55s until the target 3T field is attained- This is the fastest that the power supplies allow- Could a breakdown at lower Bphi be designed ? |
| May 2 2008 12:48:49:623PM | 1080502006 | Basil Duval | Pre: Lower Ne- 0.4 -> 0.3 (this is a diverted lower null config)
Post: OK- Vphi still positive- little change here- |
| May 2 2008 12:49:50:483PM | 1080502007 | Basil Duval | Pre: Lower Ne- 0.3 -> 0.2
Post: OK- Significant Hard X- This is as low as we can go in this config- time to start to play with Ip- |
| May 2 2008 12:51:48:250PM | 1080502008 | Basil Duval | Pre: Ne back to 0.3 (same as for 006) Ip raised from 600-650kA (lower q)
Post: OK- Disrupt at 1.5s- Odd ? qe reconstructed as 2.9 -> 3.3 at disruption although the Ip does not seem to change much- Are we looking at minor shape changes or is there a current profile change or ??? |
| May 2 2008 12:54:02:677PM | 1080502009 | Basil Duval | Pre: Ne ramp to higher Ne- Try to cover the whole Ne range in one discharge
Post: OK- Disrupt again, but nothing to get excited about with Vphi- Looks like we're not in a good range of parameters for this diverted configuration, so it is time to look at a limited equivalent to see if there is any change in rotation direction (as would be expected from the TCV observations) |
| May 2 2008 12:26:46:547PM | 1080502010 | Basil Duval | Pre: Keep shape and Ip- go for LIMITED config
Post: Worryingly little change- density kind of high-> look towards lower Ne ? |
| May 2 2008 12:25:28:607PM | 1080502011 | Basil Duval | Pre: Repeat: Looking for lower Ne (0.8 and 0.4 to cover same range as for diverted config)
Post: Still rather high... (Vtor boring and still zero or co-current) |
| May 2 2008 12:24:13:683PM | 1080502012 | Basil Duval | Pre: Go for 0.8 (John units this time)
Post: Still rather high... (Vtor still boringly similar...) |
| May 2 2008 12:22:26:230PM | 1080502013 | Basil Duval | Pre: Go for 0.8 (John units) again
Post: Still only got down to ~1.1- Perhaps we could reduce the gas feed in the early discharge formation (during the Bphi ramp) |
| May 2 2008 12:17:18:320PM | 1080502014 | Basil Duval | Pre: Lower density (aiming for average 0.8e20)
Post: Got a "step" in the toroidal velocity response at ~0.8sec i.e. after the Bphi was established- This could be what we are looking for if there is Hysterisis in that the rotation did not decrease again when the density went up |
| May 2 2008 12:20:22:010PM | 1080502015 | Basil Duval | Pre: Lower density further
Post: Looking INTERESTING ! density slightly lower gave a "transition" a little later in discharge- Still not occurring in stationary conditions- Aim to reduce density further and when stabilised, attempt a programmed density ramp to manually take the plasma across the threshold that seems to be ~0.8 on C-MOD for this shape (Must not forget that this is LIMITED) |
| May 2 2008 12:35:49:537PM | 1080502016 | Basil Duval | Pre: Go for still lower Ne, rest of config similar
Post: OK ! now the whole duration is at the higher rotation speed (Ne is lower) Assuming this means that we are now "below" threshold, then we may now program a density ramp from ~1s until the end of the discharge to get a transition. |
| May 2 2008 01:11:37:143PM | 1080502017 | Basil Duval | Pre: Density ramp from 1s from ~0.75 to 1.0- Look for a change during this period
(Note: edge seems little affected (like TCV) and profile is changing inside q ~1.5 which is again in agreement with TCV- Interesting, however, if +ve velocity is co-current, we are obtaining a transition Co to Counter with increasing density- This is the opposite to the TCV observation which has this behaviour for DIVERTED discharges- How limited are these C-mod discharges ? (UK spelling on purpose !) Post: BLIP- try again... PostPost: Fuse replacements etc. require over an hour- End of this part of the session- Get the ramp performed during Alex's part of the programme- Suggest: 1) the density ramp that we had hoped for this discharge 2) Repeat the SAME density ramp with 15-20% higher current (800kA) If we see anything, we will immediately have to look into the following 1) Complete profiles reconstructed from all diagnostics 2) Behaviour of the edge D-rotation (HFS gas jet) 3) Mode changes near to or across the Vphi change (resolved by the magnetic structure as a radius (i.e. inside and outside the Vphi affected region)) 4) Double the Argon input for these low densities to exclude any parametric effect- 5) take Bphi up in a couple of steps to see if this can all be performed at full field (TCV results have only good things to say about increasing the toroidal field but this has really not been extensively investigated) If you have contingency time in C-Mod's planning, can we request more shots ? A big thanks to everyone for the help ! _basil |
| Physics Operator Comments | |||
| May 2 2008 09:43:17:607AM | 1080502001 | Jim Irby | load from 1080215001 --- locked mode standard shot
rcur=1000, prefill -0.525 to 0.500 s, 200 ms of argon, 800 kA, 5.45 T loaded RGA filament failed early this morning. Now back to rga head on ps1. GV1 closed as it cleans up. BP 4.8e-7 Torr in torus. 08:00 --- having issues with pcdaqcamac. Reboot does not seem to help. Josh will be in by 08:40 08:02 --- we can ping pcdaqcamac 08:10 --- test shots run okay now 08:30 --- no cycle test okay |
| May 2 2008 09:12:47:863AM | 1080502002 | Jim Irby | plasma into rampdown but I forgot to enable argon |
| May 2 2008 09:31:42:630AM | 1080502003 | Jim Irby | argon enabled --- 200 ms starting at 0.3 s
Hirex gatevalve enabled cell entry: reboot TS computer, start up a transmitter or two cell access done by recool+10:04 plasma --- some runaways --- got locked mode density risetime slower than on shot 02 |
| May 2 2008 09:59:21:713AM | 1080502004 | Jim Irby | load from 1080430002 --- rcur 1000, bt 3.3 T
seg01 and seg03 active loaded TF to 3.0 T --- 82.27kA loaded checked prefill after I had pushed the button ---- 26 ms plasma into rampdown ---- |
| May 2 2008 10:03:58:640AM | 1080502005 | Jim Irby | Ip from 600 to 650 kA
TF current from 82.27kA to 78.5kA loaded plasma into rampdown --- Bt 3.008T --- ohmic h-mode around 1.2 s some hard early --- current rolled over but recovered at 0.12 s |
| May 2 2008 10:19:59:307AM | 1080502006 | Jim Irby | nl_04 request from 0.4e20 to 0.3e20/m^2
loaded plasma into rampdown --- density about right |
| May 2 2008 10:28:41:173AM | 1080502007 | Jim Irby | nl_04 request to 0.2e20/m^2
loaded plasma into rampdown --- lots of snow |
| May 2 2008 10:40:06:293AM | 1080502008 | Jim Irby | Ip to 700 kA
nl_04 request back to 0.3e20/m^2 loaded plasma to 1.56 s --- pushing q |
| May 2 2008 10:59:45:463AM | 1080502009 | Jim Irby | prefill from 26 to 24 ms --- disruption black magic
nl_04 request now ramping from 0.5 to 1.8 s from 0.3e19/m^2 to 0.8e19/m^2 plasma for 1.44 s --- h-mode and then.. |
| May 2 2008 11:06:12:763AM | 1080502010 | Jim Irby | go limited --- CLEARIN from -0.0005 to -0.0115 m --- inner gap was 0.011 m last shot
Ip from 700 to 650 kA loaded plasma for 1.8 s --- inner gap still non-zero |
| May 2 2008 11:19:53:383AM | 1080502011 | Jim Irby | ramped CLEARIN more negative to keep it on the wall
nl_04 ramp now reversed: 0.5 to 1.8 s, 0.8e19/m^2 to 0.3e19/m^2 loaded plasma for 1.36 s --- may have ramped CLEARIN too hard --- stayed limited though density overshot and then didn't rampdown |
| May 2 2008 11:33:50:457AM | 1080502012 | Jim Irby | nl_04 now flat at 0.8e20/m^2
CLEARIN ramped to -0.018 at 1.6 s instead of -0.020 m loaded plasma into rampdown --- inner gap okay |
| May 2 2008 11:48:35:377AM | 1080502013 | Jim Irby | nl_04 request from 0.8e19/m^2 to 0.6e19/m^2
CLEARIN at 1.6s from -0.018 to -0.0185 m loaded argon from 0.30 to 0.45 s (150 ms from 100 ms) plasma for 1.717 s --- clearin better |
| May 2 2008 11:58:54:603AM | 1080502014 | Jim Irby | nl_04 request to 0.5e19/m^2 --- reduced ramp up also
CLEARIN back to -0.02 m at 1.6 s loaded plasma into rampdown --- density okay CLEARIN good |
| May 2 2008 12:16:59:803PM | 1080502015 | Jim Irby | nl_04 request to 3e19/m^2
loaded plasma into rampdown --- density lower, but not 3e19/m^2 |
| May 2 2008 12:27:27:390PM | 1080502016 | Jim Irby | nl_04 request to 2e19/m^2 --- also ramped down before 0.5 s to reduce early gas puff.
gas is off by 0.5 s, so what we do early will matter --- walls should unload a little too as we go. loaded plasma into rampdown --- nl 0.44e19/m^2 |
| May 2 2008 01:06:58:920PM | 1080502017 | Jim Irby | nl_04 ramping from 1.0 to 1.5 s from 2e19/m^2 to 6e19/m^2
loaded fizzle even w/o oh2u commutation oh2u PFN current only about 20kA 13:05 **** down about 1 hour to investigate blown fuses ***** |
| May 2 2008 02:47:46:837PM | 1080502018 | Jim Irby | 14:25 This shot will be a PLC controlled test of the commutation banks
data system issues ---- no Rogowski data data back commutation looks good |
| May 2 2008 02:56:54:487PM | 1080502019 | Jim Irby | Try for plasma --- try to get shot for Basil with the density ramp
no power shot instead ---- data system problems again Josh needs access to power room |
| May 2 2008 04:10:43:137PM | 1080502020 | Jim Irby | One more no power test
looks okay --- got gas |
| May 2 2008 04:24:38:757PM | 1080502021 | Jim Irby | Another no power shot --- oh2 com didn't charge ---
power room entry --- switches had been left in off position following fuse check |
| May 2 2008 04:34:04:870PM | 1080502022 | Jim Irby | no power shot
|
| May 2 2008 05:00:31:440PM | 1080502023 | Jim Irby | try for plasma
fizzle --- oh2s misbehave from startup at -1.1 s |
| May 2 2008 05:14:14:903PM | 1080502024 | Jim Irby | try again
all supplies invert at -0.07 s??????????? type II fault ef1u I^2t |
| May 2 2008 06:34:55:357PM | 1080502025 | Jim Irby | Br0 gain from -0.3 to 0.0 s changed from 5 to 10: drive supplies a little harder during time they have been drifting off
no power shot -------- PEI air switch problem ******************************************* *******************stop******************** ***********work to do next week************ ******************************************* |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 08:22:50:280AM | Test | Ok | cycle test |
| 2 | 09:04:19:733AM | Plasma | Ok | |
| 3 | 09:24:04:343AM | Plasma | Ok | |
| 4 | 09:42:29:683AM | Plasma | Ok | |
| 5 | 09:57:13:163AM | Plasma | Ok | |
| 6 | 10:09:46:080AM | Plasma | Ok | |
| 7 | 10:22:26:107AM | Plasma | Ok | |
| 8 | 10:34:56:960AM | Plasma | Ok | |
| 9 | 10:48:00:923AM | Plasma | Ok | |
| 10 | 11:01:35:777AM | Plasma | Ok | |
| 11 | 11:14:18:100AM | Plasma | Ok | |
| 12 | 11:27:15:967AM | Plasma | Ok | |
| 13 | 11:39:55:557AM | Plasma | Ok | |
| 14 | 11:53:03:987AM | Plasma | Ok | |
| 15 | 12:08:57:267PM | Plasma | Ok | |
| 16 | 12:24:16:510PM | Plasma | Ok | |
| 17 | 12:38:24:837PM | Plasma | Bad | OH2U did not commutate |
| 18 | 02:30:58:083PM | Test | Ok | OH1, OH2U and OH2L commutation test |
| 20 | 03:13:54:763PM | Plasma | Bad | No Power Shot |
| 21 | 04:16:31:390PM | Plasma | Bad | OH2 did not charge, needs to be reset |
| 22 | 04:32:00:510PM | Plasma | Bad | OH2 failed to charge. Spellman power supplies were not turned on. |
| 23 | 04:45:40:943PM | Plasma | Bad | The OH2s did not follow their commands |
| 24 | 05:05:15:803PM | Plasma | Bad | OH2s did not follow command |
| 25 | 06:28:36:663PM | Plasma | Bad | No power shot |
| System Availability | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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