| Miniproposals | ||||||||||
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| Operators | |
| Session leader(s): | Yuichi Takase |
| Physics operator(s): | Steve Horne |
| Engineering operator(s): | Vinny Bertolino,Joe Daigle |
| Engineering Operator Run Comment |
| horne/takasi |
| Session Leader Plans |
| Physics Operators Plans |
| Session Leader Summaries |
| Entered: Jul 7 2004 03:49:13:820PM |
| Author: To Be Determined |
| MP117 He3 Heating @ 8T SL: Takase PO: Horne EO: Bertolino/Daigle Run objectives: 1. He3 concentration scan @ nel=1.0e20 2. density scan @ best He3 concentration Objective #1 was achieved. As expected, no He3 is not good and too much He3 is not good for heating. The observed heating was fairly insensitive to He3 concentration in the intermediate range of He3 concentration (estimated to be n_He3/n_e < 10%). The bottom TCI window cracked on shot 11, and Objective #2 was not achieved. Plenum #1 18.8 psi He3 Run delayed because of burning G-10 smell in the cell (F-side reentrant) shot 01 test OH test He3 concentration scan 02 pla 6.9T, 0.8MA, disrupt @ 0.43s (chopper IOC) He3 test pulse 90V X 50ms @ 0.8s 03 pla 8T, 1MA (like 950530018), He3 wasn't enabled He3(McPh)=1 unit, nel=1.05->0.9, P_rf=1.8MW, 1.1e13 neuts/s, Ti0=1.6->3.0keV, Te0=2.5->3.2keV, 65->75kJ 04 pla He3 on (90V X 50ms @ 0.8s, nel increment 0.2), Ar on, longer flattop He3(McPh)=3, nel=1.2->1.0, P_rf=2.1MW, 0.75e13 neuts/s, Te0=2.2->3.2keV, 65->80kJ N2 leak during RECOOL 05 pla He3 (90V X 15ms @ 0.8s + 20V till 1s) He3(McPh)=1, nel=1.05->0.9, P_rf=2.0MW, 1.3e13 neuts/s, Ti0=1.8->3.6keV, Te0=2.6->3.6keV, 66->76kJ N2 leak during RECOOL delay due to TF crowbar 06 pla He3 (90V X 15ms @ 0.8s + 40V till 1s) runaway shot, disrupted @ 0.53s 07 pla He3 (90V X 15ms @ 0.8s + 40V till 1s) He3(McPh)=2, nel=1.05->0.9, P_rf=2.1MW, 0.8e13 neuts/s, Ti0=1.8->3.2keV, Te0=2.4->3.1keV, 65->83kJ 08 pla He3 (90V X 15ms @ 0.8s + 60V till 1s), heating not as good He3(McPh)=6(saturated), nel=1.1->1.2->1.1, P_rf=2.1MW, 0.2e13 neuts/s, Ti0=1.6->2.0keV, Te0=2.5->2.7keV, 66->68kJ TF didn't flattop leak again, long delay to fix the leak E-port blower was not on 09 pla He3 (90V X 15ms @ 0.8s + 50V till 1.1s) He3(McPh)=6, nel=1.05->1.1, P_rf=1.8MW, 0.3e13 neuts/s, Ti0=1.5->2.2keV, Te0=2.4->3.1keV, 65->80kJ leak again 10 pla He3 (90V X 15ms @ 0.8s + 30V till 1.1s) He3(McPh)=2.5, nel=1.0->1.0, P_rf=2.0MW, 0.8e13 neuts/s, Ti0=1.6->2.8keV, Te0=2.5->3.1keV, 63->77kJ start density scan 11 pla He3 (90V X 15ms @ 0.8s + 30V till 1.1s) nel program 1.4e20 disrupt @ 0.66s TCI window cracked end of 8T part of run |
| Physics Operator Summaries |
| Entered: Jul 7 2004 04:36:54:583PM |
| Author: To Be Determined |
Run 950531 -- 7.9 T operation: Takase (SL) Horne (PO) Bertolino & Daigle (EO) Setup: Set up as for last shot yesterday (950530018) There is a smell in the cell. Mark Iverson votes for burned G-10. Andy Pfeiffer votes for phenolic. I think G-10. (Smelles like burned neutral beam insulator.) Turned out to be a small widget on the F-Side periscope belonging to Jim Terry. It was G-10. Do an OH test shot -- paranoia, mostly. Coldstart complete at 8:06 Starting fill -- 2.e-5, D2. If we start the TF before -2.0 sec, need to change integrator times on bus rog and on magnetics. Granetz timing.exe (Fortran!) to do the latter. Summary -- Basically a good run for physics but not good for the machine. Shots 3-5 had IP=1 MA, TF = 8. T. Shots 7-10 were IP=1.MA, TF = 7.9 T. 6 runaway electrons; shot 11 knocked a tile loose which fell on the TCI window and cracked it. Machine went up to several millitorr before the gate valve closed. We set up for tomorrows run using nl_zmeter; TF back to 5.3 T. Shots 12-14 were fizzles. Plan to discharge clean tonight. The machine ran remarkably well at 8 T and 1 MA as far as plasma was concerned. Adjustments to the TF supply to keep us on high tap for longer seem to have worked; compare TF traces for shots 8 (almost no flattop) and 9 (400 msec flattop.) Increasing the TF voltage -- either rectification or inversion -- will reduce coil heating. Unplugging or disabling some blowers around E and F port before the run caused an ice buildup on E port and an intermittent leak. OH joint resistance remained nominal all day. Shot log: 1 oh test -- didn't work. Alternator problem. 1 again -- worked. oh2l is .62 micro-ohms -- same as last shot yesterday. 2 ip = 800, tf setting 200. Should flattop at around 6.7 T perhaps 30 msec after breakdown. He 3 (pulse_gas2) 90 v for 50 msec starting at .8 sec. Disrupted at 800 KA. Chopper ioc. The plasma survived the 4 KA efc kick from the chopper, and disrupted vertically when the EF2 U railed at 4 KA. TF flattop at -192. Went up, only 65 KA on Granetz' halo scope. Plan for success. IP to 1 MA, request 234 on tf (to get 224 or 8.0 T) Slow clearin ramp, reduce zxu gain -- both to keep ef2U off rail. 3 Plasma. No He3. EF2L still on rail. Enable HE 3. Hold IP flattop till 1.1 sec Adjust all other gains appropriately Drop rxu P gain from 2.4 to 2 Set tf start time to -1.8 msec 4 Disruption at about 1.2 TF Crowbar. No real change in TF flattop; we loose too much voltage resistively. A leak (Nitrogen up on RGA) during cooling. Put tf back to -1.7 Many small tweaks to rampdown, NL_04, and He3 voltage. 5 TF crowbar but plasma survives till 300 KA. Reduce margin angle on inversion of TF. Tweak a side gas programming to help the density feedback The leak is back & worse. Shut down cooling; it went away. Drop TF setting from 234 to 230. Should give flattop at 7.9 T at around .8 sec. 6 Nasty runaway shot. TF flat-top looked better. Fill to 2.3e-5 TF Fizzle delay at 100 msec 7 Good Shot. Raise He3 step to 60 8 Good shot, but TF flattop not till after 1 sec. Ask for a little extra cooling time & see if that helps. Big density rise presumably due to He3 pulse. Back to 50 V on He3 & hold till 1.1 The leak is back. Go in to cell to a) purge in He and b) put a blower on E port. Also tweak the tf supply to stay on high taps a little longer. Turns out some of the heating had been inadvertently been disconnected from E port. Turn it back on. 9 Nice shot. Breakers pulled; apparently there is an alternator limit on integral I * t which we're on the hairy edge of. Tweak it. TF tweak to stay on high taps longer worked. Flat-top starts at .7 sec (compared to 1.0 sec last shot). Set He3 voltage to 30 v. 10 Nice shot. Adjust nel to 1.4e20. 11 Bad news. Disruption at .65 sec; machine went to several millitor, then pumped back down. All gate valves closed. TV shows an object fell into the plasma around H port somewhere. Theory is there's a broken window in the TCI. Rick just confirmed a crack in the window, with a melted gusset tile sitting on it. === Ian takes over as session leader to prepare for run tomorrow. ===== Load segment 2 from 950509023 Bless the V's Load wire 14 (nl_zmeter) from 950519005 wire 14 on top of nl_04. Verify preprogrammed gas valve voltage 12 Fizzle. Try dropping B_r offset from 7.5e-3 to 7.e-3 13 Fizzle. Drop fill to 1.8e-5 14 Fizzle. Discharge clean overnight & try again tomorrow. |
| Session Leader Comments |
| Physics Operator Comments |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 08:43:31:820AM | Test | Ok | coax test |
| 2 | 09:20:58:660AM | Plasma | Bad | chopper IOC |
| 3 | 09:42:18:480AM | Plasma | Ok | |
| 4 | 10:05:33:320AM | Plasma | Ok | tf cbar after fizzle detector |
| 5 | 10:47:13:660AM | Plasma | Ok | tf cbar -- plasma ok |
| 6 | 11:45:44:420AM | Plasma | Ok | |
| 7 | 12:10:24:460PM | Plasma | Ok | |
| 8 | 12:30:14:770PM | Plasma | Ok | |
| 9 | 01:44:37:290PM | Plasma | Ok | |
| 10 | 02:05:47:420PM | Plasma | Ok | |
| 11 | 02:33:21:420PM | Plasma | Ok | |
| 12 | 03:48:10:760PM | Plasma | Ok | low field |
| 13 | 03:59:45:760PM | Plasma | Ok | |
| 14 | 04:09:27:000PM | Plasma | Ok | |