| Miniproposals | ||||||||||
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| Operators | |
| Session leader(s): | Steve Wolfe |
| Physics operator(s): | Steve Scott |
| Engineering operator(s): | Bill Cochran |
| Engineering Operator Run Comment |
| Power tests for Reverse field startup |
| Session Leader Plans |
| Entered: Feb 11 2011 10:30:49:970AM |
| Author: Steve Wolfe |
Session Leader plan for Monday, 2/14/2011 MP#298a (sort of): Reverse field startup SL: wolfe PO: Scott ECDC in D2 (2e-4 Torr) requested over the weekend. Run starts at 10:00AM (est) with power system tests Plasma attempts should start around 13:00 and end by 17:00 or preferably earlier. The beginning of the day will be spent testing the power systems and verifying the reconfiguration to reverse field/current operation. SL will monitor magnetics signals and dpcs inputs for consistency. Physop may be required to program waveforms for some coils. Preferably EO will have reference shots from 2007 for this purpose. We'll start tests with coils using TMX supplies, proceed to PF coils using alternator, and end with TF tests under PLC control. Assuming all tests are successful we will then proceed to plasma tests. The goal of the plasma tests is to develop a reasonably reliable startup in the reverse field configuration for the next couple of weeks of experiments. The target shot should be suitable as a starting point for Tuesday's run on MP#654 "I-mode with LSN and unfavorable grad-B topology". Engineering setup should be as for 1110128003 except A-coil setup should be -Dtop +Dbot +Jtop -Jbot (reverse the signs) No cryopump. They will need it on Tuesday, but that's just a pg4 change on the startup and not worth the time or expense of cooling it down for a few shots. No RF is required. Physop should start with segment #1 from 1110128003 and make all changes required for reverse field (see email and/or logbook entry under HYBRID for 1110208). Suggest starting with RCUR offset=-3500, BR_0=0. Also, change PG4 puff from 50msec to 25msec, since we won't be using cryopump. Change Seg1 title to something like "2011 reverse field non-cryopump startup". For segment#2, Physop should import seg#2 from 1070726018 (+800kA, +5.4T), as called for in tomorrow's MP. This is already set for reversed field, but the magnetics predictors (wires 1-8 and 12) need to be recalculated. Note that this was the run on which we lost f19; hopefully that won't happen again! Since 1070726018 already had B21_proj set for reverse field, it isn't necessary to recalculate this predictor, but there has been a minor change in the error field correction algorithm since then, so it wouldn't hurt. Note that if this is being done ahead of time, setting the keyword arg to ACOIL_CONF="-Dtop +Dbot +Jtop -Jbot" is required to force the correct calculation to be done; after the CALL the text in the Alg.Version window should indicate phi=18.67 degrees and the ACOIL setting as shown. Segments#3 and 4 should be zeroed, unless the physop wants to go through the flip and fold exercise for these for conversion to reverse field as well. Since we won't be doing tests with these, it's probably better to zero them out than to leave untested, possibly incomplete, modifications lying around. The dpcs_fizzle (ASYNC_PROS) setup needs to have the SOURCE_SHOT changed from 1090731017 to 1060517007 for reverse field. Shot plan: 1. Try for plasma using the setup specified above. (1 shot) 2. Tweak startup fields and offsets, and/or gas puffs, based on results. Expect first field tweak to be RCUR offset or IC_EF4U current; gas tweaks to PG4 or seg1 PG3 maintenance level. Aim is non-bouncy reliable startup without runaways, but we may settle for less if it's getting late. (0-5 shots) 3. Once successful startup is obtained, verify programming in seg#2 and try for full length plasma. (0-3 shots) 4. Declare success based on between 1 and 3 successful plasmas (sustained into rampdown) in a row. |
| Physics Operators Plans |
| Entered: Feb 11 2011 03:04:04:823PM |
| Author: Steve Scott |
| -----------------
Engineering Setup ----------------- *** REVERSE FIELD OPERATION *** Run begins at 10:00 and ends at 17:00 Power systems as on: Acoil: -Dtop +Dbot +Jtop -Jbot (for reverse field) 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 Enable gate-valves and shutters: ECE, VUV, HiREX Sr, Xeus Leave z-bolo shutter as is (should be open) Torvac gatevalve toggle (yes/no): no Boronization(yes/no): no Overnight ECDC (yes/no): yes ICRF(yes/no): no LH(yes/no): no Cryopump (yes/no): no DNB (yes/no): no Vessel temperature: 35/35/35 ------------------------------ ECDC Parameters (if requested) ------------------------------ gas and pressure: D2 at 2e-4 Torr over the weekend sweep: 44/45/103 cm scan: 20/120 s Today's objective is to confirm that all power supplies and PCS configuration parameters are properly set for reverse-field operation, and to make at least one plasma suitable for the start of the I-mode experiment (MP654) scheduled for Tuesday. We will start at 10 AM with power-tests of PF and TF coils. Presumably, these will be similar to the tests on 1070717001 thru 1070717013. We will then move on to try to make a plasma. Probably the transition from power supply test shots to plasma attempts will occur at about 1 PM. A PCS configuration has been prepared and saved according to the following prescription: segment 1 loaded from a recent shot = 1110128003 (which was a forward-field shot) and segment 2 was loaded from an old reverse-field shot 1070726018. Then all necessary changes to make the control system ready for reverse-field operation were implemented, as per Steve Wolfe's emailed instructions a few days ago. These changes include: In segment #1, 'flip' IC_OH1, IC_OH2U, IC_EF1U, IC_EF1L, IC_EF2U, IC_EF2L, IC_EF4U and IP In segment #1, 'flip' OH1_VOLT, CHOPPER, OH2U_VOLT, OH2L_VOLT, EF1U_VOLT, EF1L_VOLT, EF2U_VOLT, EF2L_VOLT, EF4_VOLT, EF3_VOLT, TF_CURRENT In Segment #2, recalculated all of the predictors. When recalculating the predictor for B21_PROJ, the argument was set to ACOIL_CONFIG="-DTOP +DBOT +JTOP -JBOT". Verified that the field showed phi=18.67 degrees ... changed the source shot for the fizzle detector to 1060517007. verified that the dpcs_xjump threshold is set to 1.0e15. verified that the dpcs_piezo_chopper OUTPUTS was "pulse_gas1", "pulse_gas3", "H-Bot" Changed the offset for RCUR in segment 1 from +3500 to -3500. verified that the offset for BR_0 in segment 1 is set to zero. shortened the prepuff from 50 to 25 ms. |
| Session Leader Summaries |
| Entered: Feb 14 2011 03:52:22:813PM |
| Author: Steve Wolfe |
Session Leader summary for Monday, Feb 14 Reverse field power tests and plasma startup (MP#298a) SL: wolfe PO: Scott EO: Dekow, Cochran Power testing began on schedule, around 10:00AM, with testing of the TMX supplies. These all checked out. There was a two and a half hour delay before the alternator came up to speed, and we resumed testing at 13:00 with the EF3. All the power tests ran successfully and without incident. Commutation tests of EF1 and OH's were performed because of a change in the CAMAC crate that drives the triggers. This was completed at about 15:00. We took advantage of the last few power tests to exercise the gas valve; B-main needed an extra pulse. First plasma attempt was #16, and it ran full length with a good startup. It looks like reversing the sign on the RCUR offset to -3500 is appropriate. The density was above the program as the walls were loaded, but otherwise the shot was just like the reference from Dennis' MP. A repeat for #17 had a small bounce in startup, density came down, and the shot disrupted at 1.3sec with a possible locked mode. For shot#18 we tweaked up the gas to fix the bounce, and got a good startup again, but the disruption was still there, and I think this is a locked mode. The Acoil was on with B21_PROJ, reaching 1500A. Probably some tweaking on the density program will be needed tomorrow, but this should be done with the cryopump on and the RF pulse as requested. |
| Physics Operator Summaries |
| Entered: Feb 14 2011 03:41:04:577PM |
| Author: Steve Scott |
| This was a highly successful startup in reversed field.
Shots 1 thru 15 were standard power-supply / coil tests. These proceeded nominally. The only hiccup was a ~2 hour delay for the alternator, which started from a cold-start this morning. We achieved a full-length plasma on the first attempt, shot 16. Shot 17 had a little bump on the startup, and it disrupted at about 1.3 sec. On shot 18 we increased the prefill a little, and got a better startup. Shot 18 still disrupted, a little later than in shot 17. Recommend starting with shot 18 as the reference shot for tomorrow, and adjust the gas as needed for use with cryopumping and RF. |
| Session Leader Comments | |||
| Feb 14 2011 10:01:07:247AM | 1110214001 | Steve Wolfe | Shot#1: EFC test Got about 1kA, negative signal on efcl. BR_0 is negative. Timing is not consistent with 1070717001, but the connection looks ok. It looks like the chopper is still getting the demand from DPCS, which is still set for normal field. Should have requested a positive chopper demand signal. |
| Feb 14 2011 10:13:32:780AM | 1110214002 | Steve Wolfe | Shot#2: EF2U test under PLC control. positive current positive flux on inner wall, looks fine. EF3 induced current same as old shot |
| Feb 14 2011 10:21:39:277AM | 1110214003 | Steve Wolfe | Shot#3: EF2L test under PLC control. Looks correct. We are not getting data from ha2bright or the CII signal. Emailed Josh and JT. |
| Feb 14 2011 10:34:08:640AM | 1110214004 | Steve Wolfe | Shot#4: Acoil test under Hybrid control This is based on the shot from 1070717004 which was supposed to be hybrid but had actually been run as PLC control. Looks correct, follows drawn waveform less about 600A, polarity on LM loops matches old shot, flattop amplitude pretty close. |
| Feb 14 2011 01:12:10:617PM | 1110214005 | Steve Wolfe | Shot#5: EF3 test PLC control Got Ha2bright this time. EF3 negative pulse, negative flux, looks ok. |
| Feb 14 2011 01:22:19:773PM | 1110214006 | Steve Wolfe | Shot#6: EF4 forward bridge only PLC test 1Ka positive current, positive flux, Bz0 is positive .05 EF3 current induced |
| Feb 14 2011 01:29:09:453PM | 1110214007 | Steve Wolfe | Shot#7: EF1U forward bridge only PLC control Positive 2kA positive flux. OK Lab and cell access before next shot, which will be EF1L |
| Feb 14 2011 01:38:58:370PM | 1110214008 | Steve Wolfe | Shot#8: EF1L forward bridge test, PLC control Positive 2kA, positive flux, mflux looks normal test ok |
| Feb 14 2011 01:51:55:107PM | 1110214009 | Steve Wolfe | Shot#9: OH1 PLC test (forward bridge) Physop will load the plasma startup shot, so we can start looking at the error signals. positive ~2.8kA, positive flux, good mflux Initial RCUR offset before OH current is ~ -3000A-m, so the offset may be close. |
| Feb 14 2011 01:58:41:920PM | 1110214010 | Steve Wolfe | Shot#10: OH2U PLC test (forward bridge) +2.8kA, positive flux, mflux ok. |
| Feb 14 2011 02:05:29:200PM | 1110214011 | Steve Wolfe | Shot#11: OH2l PLC test (forward bridge) +2.7kA (no buzzer) positive flux, mflux ok for oh2l |
| Feb 14 2011 02:14:39:503PM | 1110214012 | Steve Wolfe | Shot#12:TF 50kA PLC test +50kA, positive flux, mflux shows an outboard null Bz0 around +1mT |
| Feb 14 2011 02:21:37:210PM | 1110214013 | Steve Wolfe | Shot#13:TF 100kA PLC test Enable B-top and B-main gas valves for this shot +100kA in TF ok Got gas from B-top, nothing from B-main. It needs exercising. Physop will program something more agressive for seg1 pg3 for next test |
| Feb 14 2011 02:42:30:343PM | 1110214014 | Steve Wolfe | Shot#14: EF1 commutation test, with gas The fizzle detector is set for 0.5sec, so just run segment 1 with a 100msec 90V pulse, seg 2 off so the nl04 feedback doesn't flood the machine. EF1 Commutation looks ok, got gas from B-main ok. Next: Physop will put back the normal seg1 pg3 puff. Engineers will run an oh1 comm test |
| Feb 14 2011 02:50:20:620PM | 1110214015 | Steve Wolfe | Shot#15: OH (all three) commutation test, with gas The fizzle detector is set for 0.5sec, so just run seg1 with normal seg1 pg3 puff. 10kA oh commutation looks ok. Gas looks ok pressure (with no EF4) ~.06mTorr Next: try for plasma. |
| Feb 14 2011 03:11:38:330PM | 1110214016 | Steve Wolfe | Shot#16: try for plasma. plasma full length. A few injections early, and a marfe before 0.4sec, but all in all, a good start. No gas puffing in segment 2, and the density is dropping down to 6e19, and the program calls for 6. Next: Just repeat, try for 2 in a row |
| Feb 14 2011 03:27:16:243PM | 1110214017 | Steve Wolfe | Shot#17: Just repeat, try for 2 in a row see if the density comes down. plasma to 1.3sec, little bounce and some runaways early. Looks like an injection, something coming in around 1.16sec The density is down to 6e19, with some puffing. Could be a locked mode, the ECE looks ratty. A-coil is on. Next: do one more, with some startup tweaks |
| Feb 14 2011 03:36:59:447PM | 1110214018 | Steve Wolfe | Shot#18: do one more, with some startup tweaks plasma to 1.35sec, no runaways, no bounce still has a possible locked mode. Density is around 5e19, puffing gas. Startup seems robust enough, the shot will need to be tweaked up with rf and the cryopump tomorrow. END OF REVERSE FIELD TESTs |
| Physics Operator Comments | |||
| Feb 14 2011 10:04:25:677AM | 1110214001 | Steve Scott | System will be under PLC control. This will be a test of EFC.
Compared to 1070717001, this shot got more EFC current early (t<0.077) but the EFC current waveform overlays 1070717001 exactly thereafter. Important note: see SL comments. When testing EFC "under PLC control" it appears that the hybrid is not entirely ignored. It also appears that we got a gas puff on this shot, which was missing from the reference shot 1070717001. Will turn off gas puff for next shot. |
| Feb 14 2011 10:16:54:783AM | 1110214002 | Steve Scott | Test of EF2U under PLC control.
EF2U current waveform overlays reference shot (1070717002) exactly -- iscope11 is a real help in comparing power shots that should be identical! Also the pickup on EF3, EF4, and EFC is exactly the same. The gas puff is gone, as requested. The toroidal field is about 0.002 Tesla higher than on 1070717002. |
| Feb 14 2011 10:18:58:360AM | 1110214003 | Steve Scott | Successful test of EF2L. Looks identical to 1070717003. |
| Feb 14 2011 10:32:15:290AM | 1110214004 | Steve Scott | Loaded from 1070717004 with no changes. This should be a test of the A-coil.
Result: same sign as on reference shot 1070717004. Timing of the waveform is different, because the a-coil was put under PLC control for the reference shot (it was a flat-top waveform on 1070717004). |
| Feb 14 2011 01:11:03:783PM | 1110214005 | Steve Scott | EF3 test shot. Result: looks good. |
| Feb 14 2011 01:21:29:630PM | 1110214006 | Steve Scott | We seem to have gotten about 2% more current in EF4 on this shot compared to the reference shot, 1070717006. othrewise looks OK. |
| Feb 14 2011 01:39:08:053PM | 1110214008 | Steve Scott | Looks like a successful test of EF1-U |
| Feb 14 2011 01:49:14:130PM | 1110214009 | Steve Scott | Loaded from shot /home/sscott/pcs_scratch: 1110215000
This shot is configured as described in the PO plan. Not under DPCS control, so this should have no effect on the shot. result: good OH1 forward bridge test. reference shot = 1070717009. we got roughly 10% more current in OH1 than in the reference shot. |
| Feb 14 2011 02:12:54:420PM | 1110214012 | Steve Scott | TF test @ 50 kA. perfect repeat of 1070717012 |
| Feb 14 2011 02:16:21:983PM | 1110214013 | Steve Scott | re-enable B-top and B-main gas valves. This will act as a check on their performance, prior to our first plasma attempt in a few shots. |
| Feb 14 2011 02:29:53:790PM | 1110214014 | Steve Scott | Increase open loop PG3 demand in segment 3 to about 90 for 0.1 seconds.
Also, turn off segment 2. So segment #1 will control for the entire shot. |
| Feb 14 2011 02:43:00:880PM | 1110214015 | Steve Scott | Reloaded shot 13 from today (in order to get the original, smaller gas puff) and then turned off segment 2. |
| Feb 14 2011 03:09:45:087PM | 1110214016 | Steve Scott | At request of SL, moved the prepuff from [-0.55, -0.525] to [-0.525,-0.500].
also, turned segment 2 back on. We should be ready for the first reverse-field shot of 2011. Result: plasma on the first attempt (:)). Breakdown similar to reference shot 1070726018. |
| Feb 14 2011 03:11:56:470PM | 1110214017 | Steve Scott | Attempt: exact repeat of previous shot. No PO changes. Look to see if the early density drops a little. |
| Feb 14 2011 03:31:57:837PM | 1110214017 | Steve Scott | disrupted at circa 1.3 seconds. a little bump on the startup. |
| Feb 14 2011 03:36:42:020PM | 1110214018 | Steve Scott | Increased prepuff by ~10% and increased PG3 puff from level 35 to 40.
disruption delayed a little until 1.346 sec. NeL achieved (~0.6e20) is close to demand value. Startup is OK. recommend using this shot as the starting point for tomorrow's run. |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 09:49:45:397AM | Test | Ok | EFC |
| 2 | 10:07:11:077AM | Test | Ok | EF2U Test |
| 3 | 10:15:42:577AM | Test | Ok | EF2L Test |
| 4 | 10:28:28:787AM | Test | Ok | A_Coil Test |
| 5 | 01:08:29:120PM | Test | Ok | EF3 Test |
| 6 | 01:16:37:200PM | Test | Ok | EF4 Test |
| 7 | 01:25:00:317PM | Test | Ok | EF1U Test |
| 8 | 01:35:58:603PM | Test | Ok | EF1L |
| 9 | 01:45:23:987PM | Test | Ok | OH1 Test |
| 10 | 01:53:34:590PM | Test | Ok | OH2U Test |
| 11 | 02:01:14:830PM | Test | Ok | OH2L Test |
| 12 | 02:10:24:487PM | Test | Ok | TF 50kA Test |
| 13 | 02:17:47:807PM | Test | Ok | TF 100kA Test |
| 14 | 02:37:55:463PM | Test | Ok | EF1U&L Commutation Test |
| 15 | 02:45:44:313PM | Test | Ok | OH1,OH2U&L Comm. Test |
| 16 | 03:02:02:100PM | Plasma | Ok | All Power Sypplies Fired |
| 17 | 03:14:52:803PM | Plasma | Ok | |
| 18 | 03:30:32:980PM | Plasma | Ok | |
| System Availability | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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