| Miniproposals | ||||||||||
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| Operators | |
| Session leader(s): | Greg Wallace |
| Physics operator(s): | Ron Parker |
| Engineering operator(s): | Bill Parkin,Andy Pfeiffer,Gary Dekow |
| Engineering Operator Run Comment |
| MP: 605 LH2 Lower Hybrid Launcher Checkout and Conditioning |
| Session Leader Plans |
| Entered: Jan 18 2012 04:22:49:413PM |
| Author: Melanie Preynas |
| SL run plan for 19 Jan 2012
MP666 "Assessment of new limiter design and effects on LH wave coupling" Objective: The purpose of this experiment is to perform a systematic study how the new limiter configuration affects the coupling performance of the LH2 antenna. The first few shots will be devoted to reproducing the experimental results of the 2010-2011 campaign. Then the launcher will be pushed beyond the ICRF limiters and the new parameter space will be explored. Dependency of reflection coefficient with injected LH phase is an important marker for density depletion in front of the launcher. Power dependency as a function of launcher radial position with respect to ICRF limiters is used to investigate the effects of different temperature and density connection lengths on non-linear coupling. To allow direct comparison with previous experiments, measurements with LH limiters located flush to ICRF limiters should always be performed. Gas request: D2 majority fueling Diagnostic request: LH directional couplers LH microwave probes LH Langmuir Probes (swept mode) LH visible camera X-mode reflectometer Core & edge Thomson scattering Reciprocating Langmuir probes HXR camera GPC/2 set to 5.4T XTOMO arrays Ionization Run plan: Four kinds of experimental scans are proposed acting on the LH2's edge density, RF phasing and power. Each of these scan must be made at different launcher positions. In order to guaranty the same launcher positions for each scan (for reliable comparisons) and to optimize the number of pulse of the experimental day, it is proposed to make all the four scans for a given launcher position, then to move the launcher to the next position. Moreover, it is proposed to start with the best coupling conditions (e.g. +2.0mm), and then move the launcher to positions where the coupling is expected to be degraded. The launcher positions to be tested are: . 2.0 mm in front of ICRF limiters (2mm behind GH limiter); . flush to ICRF limiters (4mm behind GH limiter, same as 2011 campaign); . 5.0 mm behind the ICRF limiters (9mm behind GH limiter). I. Density scan at low power [6-9 shots] -1st launcher position : 5.0 mm behind the ICRF limiters (9mm behind GH limiter) 1.a Density scan: [1-2 shots] Repeat of shot 1100818004, adjusting gas puffing to cover a broad range of densities at the grill (ideally below cutoff to ~10 times cutoff density). Low power LH (200 kW), 90° degrees phasing. 1.b Repeat 1.a with 70° degrees phasing [1-2 shots]. -2nd launcher position: 2.0 mm in front of ICRF limiters (2mm behind GH limiter); 2.a Density scan: [1-2 shots] Repeat 1.a. 2.b Repeat 2.a with 70° degrees phasing [1-2 shots]if possible... (enough time for the end of the mp: increase the LH power by doing different steps?) -3rd launcher position: flush to ICRF limiters (4mm behind GH limiter, same as 2011 campaign); 3.a Density scan: [1-2 shots] Repeat 1.a. 3.b Repeat 3.a with 70° degrees phasing [1-2 shots]if possible... (enough time?) II. LH Power steps [3-6 shots]: For 90 degrees phasing and measured LH probe of 1 to 3x1018m-3 (in absence of LH power ), perform power ladder in 4 steps of 50ms of LH power: [200kW ; 300kW ; 400kW ; 450-500kW(?)] (if these levels of power are possible...)and 50% duty cycle each. 90° degrees phasings -1st launcher position: 5.0 mm behind the ICRF limiters (9mm behind GH limiter) -2nd launcher position: 2.0 mm in front of ICRF limiters (2mm behind GH limiter); -3rd launcher position: flush to ICRF limiters (4mm behind GH limiter, same as 2011 campaign); Reference shot : 1100818004 (LSN 5.4T, 700kA, Ne04 scan from 0.4 to 0.8e20, 1120117014 may be used as recent LSN. |
| Entered: Jan 18 2012 04:34:52:707PM |
| Author: Greg Wallace |
| Session leader plan for 1120119
Session Leader: G. Wallace Physics Operator: R. Parker MP: 605 LH2 Lower Hybrid Launcher Checkout and Conditioning LH Setup: Launcher 5 mm behind GH limiter (1306 counts on PLC); 60, 90, 120 degree current-drive phasing; 100-200 kW net power (~40 kW/klystron); LH on from 0.7 to 1.2s. Reference shot: 1120117014. Change nl_04 to ~ 5e19, Ip to 700 kA. Shot Plan: Pulse LH system into dummy loads until full length plasmas become available. 1) Begin with co-current 90 degree ideal phasing; disable CPS; set LH2 launcher to 5 mm behind GH limiters. Establish operations at ~40 kW/klystron, 6x20 ms picket fence pulses with bypassed CPS. Adjust launcher position if necessary to get reasonable reflection coefficients (REFCO<0.3). (3 shots) 2) Enable CPS. Vary plasma density during pulse (ramp nl04 from ~3-8e19) to test operating range. Reset CPS trip points as necessary (should not require cell access unless new trip level is above 50% reflected power). RINT10 trip level will probably need to be reset since magic-T on klystron 10 was removed. Repeat shots to verify new trip points. (3-5 shots) 4) Take shots at 60, 90, 120 current drive phasing to verify operation at a range of n|| (3 shots) 5) Increase pulse length at low power (40-50 kW/klystron) to 0.5 s; verify proper operation of CPS. (3 shots) |
| Physics Operators Plans |
| Entered: Jan 18 2012 04:40:41:473PM |
| Author: Ron Parker |
| ====================================
Physop Plan for Thursday, 19-Jan-2012 ==================================== MP 605 LH2 Lower hybrid Launcher and Conditioning MP 666 Assessment of new limiter design and effects of LH wave coupling SL: Wallace (MP 605) Meneghini/Preynas (MP 666) PO: Parker ----------------- Engineering Setup ----------------- Run begins at 9:00 and ends at 17:00 Power systems as on: 1120117014 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 H-bot with 15psi D2 Hybrid DISABLED (PG5) DO NOT fill B-div, Hybrid DISABLED (PG6) DO NOT fill H-div, Hybrid DISABLED (PG7) fill NINJA with 10 psi Ne DISABLED Gate-valves and shutters: Enable ECE, HiREX Sr, B spectrometer (Xeus and LoWEUS) Z-bolo shutter should be closed unless requested by physop Check with the physop before opening other diagnostic gate-valves or shutters. Torvac gatevalve toggle (yes/no): no Boronization(yes/no): no Overnight ECDC (yes/no): YES ICRF(yes/no): no LH(yes/no): yes Cryopump (yes/no): no DNB (yes/no): no Vessel temperature: 35/35/35 ------------------------------ ECDC Parameters ------------------------------ gas and pressure: D2 at 2e-4 Torr sweep: 44/45/103 cm scan: 20/120 s ==================================== Physics Operator Plans: The first, hopefully few, shots of the run will be used for checkout of the new TPS by running LH power into dummy loads. We'll begin plasma operations with a vanilla shot from 1120117, namely shot 014 -- 800 kA, 5.4 T, LSN -- and use this shot as a target for LH launcher conditioning, MP 605. When reasonably good low power LH shots are achieved, e.g., ~ 200 kW with 0.5 s pulse width, we'll move on to MP 666. ==================================== |
| Session Leader Summaries |
| Entered: Jan 19 2012 05:34:28:517PM |
| Author: Greg Wallace |
| Session leader summary for 1120119
Session leaders: G. Wallace and M. Preynas LH Engineering Summary: Today was the first plasma run day of the 2012 campaign for the LH system. This was also the first day of operations for the TPS upgrade. Overall the run was very successful despite a long delay to fix a vacuum leak. The new LH limiter seems to have somewhat reduced reflection coefficients, particularly on the extremes, which resulted in nearly fault free operation. There were no TPS faults during the run today and very few CPS faults, mostly when the launcher was in its most retracted position. Moving the launcher in helped reduce the number of faults. Power was limited to about 300 kW due to lack of klystron calibration at higher beam voltage and also lack of time to push power higher. |
| Entered: Jan 19 2012 05:49:02:527PM |
| Author: Melanie Preynas |
| Good day of LH experiment! Thank you everybody!
8 good shots, we have increased the LH power up to ~300kW! 3 kind of shots: - power ladder at constant power: 1120119003,8,9 - power ladder at different level of power: 12,16,17 - longer shots with constant power and three different phasings (60°, 90° and 120°): 13,14 We have moved the launcher closer to the plasma, from 5mm to 1mm behind the main limiter. Low RC achieved, around 20% for few shots at high density: 9,12 |
| Physics Operator Summaries |
| Entered: Jan 19 2012 05:08:30:947PM |
| Author: Ron Parker |
| From the Physop point of view, this was a straightforward run with essentially the same shot run throughout the day.
However one major problem developed, namely two fizzles occurred after shot 3, which prompted a look at the RGA. The latter revealed a sizable leak, with prominant lines at 14, 16, 28, 32 and 40 The base pressure hung up in the 6e-6 T range, which also confirmed the presence of the leak. The vacuum shop team first used He while monitoring the mass 4 line in the RGA to leak detect, but switched to Ar because the mass 4 backgound was too high. Two issues were found, namely a throughput leak in a new gas valve used the day before for Ne injection and, more seriously, an air leak in the polarimeter shutter. Once these were fixed, the leak stopped and operations resummed. However, about 3 hours of run time were lost. The rest of the run proceeded without incident , except for shots 10 and 11 which suffered early disruption. No obvious cause was found and the remainder of the shots ran full length. Scorecard: 17 plasma attempts, 3 fizzles (due to leak), 3 disruptions and 11 full length plasmas |
| Session Leader Comments | |||
| Jan 19 2012 09:21:29:520AM | 1120119001 | Greg Wallace | First plasma. LH into dummy loads. 6x25ms picket fence pulses. Disruption at 1.0s. LH pulses as requested.
Density on LH probes ~5e17. Will probably need to push launcher in carefully. Next shot: Set switches to launcher position! |
| Jan 19 2012 09:20:29:950AM | 1120119002 | Greg Wallace | Fizzle.
Next shot: Try again for picket fence into plasma with CPS disabled. |
| Jan 19 2012 10:09:45:540AM | 1120119003 | Greg Wallace | Good shot. LH into plasma for the first time with new TPS. CPS is bypassed. 6x20ms picket fence. JGDC reflected cable on col 2 disconnected.
Next shot: Repeat. Reconnect col 2 JGDC cable. |
| Jan 19 2012 10:08:13:760AM | 1120119004 | Greg Wallace | Fizzle.
Next shot: Repeat. |
| Jan 19 2012 10:13:04:190AM | 1120119005 | Greg Wallace | Fizzle.
Next shot: Try, try again. |
| Jan 19 2012 02:57:26:750PM | 1120119007 | Greg Wallace | CPS enabled. Several trips due to high reflection coefficient. Reflections highest on col 3, 7, 8, and 11. Can see some non-thermals on ECE!
Next shot: Move launcher in to 1292 counts (~2.5 mm behind GH limiter) to reduce reflections. |
| Jan 19 2012 03:06:36:070PM | 1120119008 | Greg Wallace | Good shot! No trips. Reflection coefficient is a little lower but still too high.
Next shot: Decrease outer gap by 5mm during flattop. |
| Jan 19 2012 03:16:06:037PM | 1120119009 | Greg Wallace | Good shot! No trips. Reflection coefficient decreases during the pulse from ~30% to ~20%
Next shot: Step power up from 20kW/klystron to 70kW/klystron during the shot. |
| Jan 19 2012 03:26:52:703PM | 1120119010 | Greg Wallace | Early disruption (30 ms).
Next shot: Step power up from 20kW/klystron to 70kW/klystron during the shot. |
| Jan 19 2012 03:41:08:770PM | 1120119011 | Greg Wallace | Disruption at 0.35 s. LH launcher looks OK.
Next shot: Try again. |
| Jan 19 2012 04:25:39:297PM | 1120119012 | Greg Wallace | Good shot. No trips. Up to 300 kW net power in final pulse.
Next shot: Switch to phase scan at constant power of ~300 kW. |
| Jan 19 2012 04:17:24:883PM | 1120119013 | Greg Wallace | Good shot! All 3 phasings with no trips. Reflection coefficient of 10-15 % with 90 deg phasing. (3.5 mm behind launcher.)
Next shot: Next shot will move launcher in to 1274 counts. |
| Jan 19 2012 04:26:22:970PM | 1120119014 | Greg Wallace | Another great shot with no trips. Refco higher at 60 deg with new position, 90 and 120 deg phasing less of a change.
Next shot: Go back to power scan from shot 12. |
| Jan 19 2012 04:40:38:760PM | 1120119015 | Greg Wallace | Power scan with simultaneous phase scan? No trips. Another good shot!
Next shot: Power scan with constant 90 deg phasing. |
| Jan 19 2012 04:53:27:147PM | 1120119016 | Greg Wallace | Another good shot with no trips. Constant 90 deg phasing for sure on this shot.
Next shot: Repeat same power staircase with constant 60 deg phasing. |
| Jan 19 2012 05:16:05:690PM | 1120119017 | Greg Wallace | Power scan at 60 deg with launcher at ~1.9mm behind GH limiter. CPS faults during lowest power sections of the pulse. Last shot of the day. |
| Physics Operator Comments | |||
| Jan 19 2012 09:04:19:047AM | 1120119001 | Ron Parker | Cold today, ~ 15 F
First shot coming up |
| Jan 19 2012 09:19:59:100AM | 1120119001 | Ron Parker | Shot 1 disrupted at 1 s |
| Jan 19 2012 09:20:13:120AM | 1120119002 | Ron Parker | Shot 2 fizzled |
| Jan 19 2012 09:46:54:853AM | 1120119003 | Ron Parker | Shot 3 ran full length, ~ 100 kW LH pulses |
| Jan 19 2012 09:51:59:080AM | 1120119003 | Ron Parker | Several delays:
Cell and power room access Alternator fault -- spun down to 1590 RPM Debugging problem in LH CTRL system |
| Jan 19 2012 10:00:42:507AM | 1120119004 | Ron Parker | Shot 4 fizzled. H_alpha is high at breakdown
Reduce prefill from 17 to 15 ms for next shot |
| Jan 19 2012 10:17:29:830AM | 1120119005 | Ron Parker | Another fizzle. RGA shows big 28 and 14 peaks. We'll check for leaks. |
| Jan 19 2012 10:48:53:927AM | 1120119005 | Ron Parker | Still leak checking. Base pressure is high, 6.8e-6 T, so this is a sizable leak.
We are continuing leak detection. |
| Jan 19 2012 02:22:50:427PM | 1120119006 | Ron Parker | Leak has been found -- polarimeter shutter -- and fixed.
Also, a new pulse valve used for injecting Ne for the 1120118 run appeared to have been leaking through the valve. But this was not an air leak. |
| Jan 19 2012 02:25:47:537PM | 1120119006 | Ron Parker | Shot 6 ran full length. LH was not pulsed, but will be on next shot. |
| Jan 19 2012 02:58:29:077PM | 1120119007 | Ron Parker | Shot 7 ran full length |
| Jan 19 2012 03:06:16:510PM | 1120119008 | Ron Parker | Shot 8 ran full length. LH didn't trip |
| Jan 19 2012 03:13:07:370PM | 1120119009 | Ron Parker | Shot 9 ran full length
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| Jan 19 2012 03:29:36:490PM | 1120119010 | Ron Parker | Shot 10 disrupted at 150 kA.More problems? |
| Jan 19 2012 03:40:39:397PM | 1120119011 | Ron Parker | Shot 11 also disrupted, this time around 350 ms. |
| Jan 19 2012 03:56:44:440PM | 1120119012 | Ron Parker | Shot came back and ran full length. |
| Jan 19 2012 04:14:51:137PM | 1120119013 | Ron Parker | Shot 13 ran full length, interesting LH shot with phase scan. |
| Jan 19 2012 04:27:11:567PM | 1120119014 | Ron Parker | Shot 14 ran full length |
| Jan 19 2012 04:32:20:187PM | 1120119015 | Ron Parker | Shot ran ful length |
| Jan 19 2012 05:10:30:270PM | 1120119016 | Ron Parker | Shot 16 ran full length |
| Jan 19 2012 05:07:15:127PM | 1120119017 | Ron Parker | Shot 17 ran full length |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 09:03:13:627AM | Plasma | Ok | |
| 2 | 09:17:41:693AM | Plasma | Ok | |
| 3 | 09:31:12:447AM | Plasma | Ok | |
| 4 | 09:54:56:470AM | Plasma | Ok | |
| 5 | 10:10:52:827AM | Plasma | Ok | |
| 6 | 02:21:56:787PM | Plasma | Ok | |
| 7 | 02:34:58:113PM | Plasma | Ok | |
| 8 | 02:56:11:650PM | Plasma | Ok | |
| 9 | 03:09:04:667PM | Plasma | Ok | |
| 10 | 03:23:22:007PM | Plasma | Ok | |
| 11 | 03:36:03:857PM | Plasma | Ok | |
| 12 | 03:49:14:827PM | Plasma | Ok | |
| 13 | 04:02:43:673PM | Plasma | Ok | |
| 14 | 04:17:13:407PM | Plasma | Ok | |
| 15 | 04:30:01:360PM | Plasma | Ok | |
| 16 | 04:46:37:593PM | Plasma | Ok | |
| 17 | 04:59:26:497PM | Plasma | Ok | |
| System Availability | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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| Jan 19 2012 02:21:44:287PM | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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