| Miniproposals | ||||||||||
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| Operators | |
| Session leader(s): | John Liptac |
| Physics operator(s): | Steve Wolfe,Ron Parker,Steve Wolfe,Ron Parker |
| Engineering operator(s): | Bill Cochran,Gary Dekow |
| Engineering Operator Run Comment |
| MP#418 LH Coupling studies SL: Liptac/Parker PO: Parker (with fill-in by |
| Session Leader Plans |
| Entered: Apr 5 2006 01:05:00:817PM |
| Author: John Liptac |
| Run Plan 1060406 LH Protection System Testing and Conditioning
Goals: 1. Test new protection scheme. 2. Evaluate 3rd harmonic arc detection. 4. If protection is working increase power and condition system. Plasma Conditions: Same type of plasmas 1060310. Low density L-mode, lower single null, nl_04~0.6, B0=5.4 T, and Ip~ 700kA. No ICRF during LH pulses. Load shot 1060310024. LH setup: Begin with the launcher at 1615 counts ~3mm behind limiter. Set mechanical phase shifters to 90 degree CD phasing. Shot 1: one segment, 90 CD phasing. LH power at 0.695 s. 20kW/klystron. Setpoint generator settings: Shot Length=5 ms, Duty Cycle=100%, Pulse Period=5 ms. Shot 2: two segments, 90 CD phasing. LH power at 0.695 s. 20kW/klystron. Setpoint generator settings: Shot Length=110 ms, Duty Cycle=9.1%, Pulse Period=55 ms. Increase power in 5kW/klystron increments until arc is observed. If system recovers for second pulse, then contract time between pulses to measure the needed recovery time. If system seems to be working increase power and try to build upon results from run 1060310. |
| Physics Operators Plans |
| Entered: Apr 5 2006 06:27:41:110PM |
| Author: Steve Wolfe |
| Physop Plan and engineering setup for Thursday, April 6
* Submitted by smw on behalf of Ron Parker MP#418 LH Coupling studies SL: Liptac/Parker PO: Parker (with fill-in by Wolfe) ECDC overnight in D2 at 2.e-4 Torr Power systems as on 1060310024 A-coil configuration: normal [+Dtop -Dbot -Jtop +Jbot] and enabled. C-coil Start=0.3sec, Invert=2.0sec ICRF transmitters #3 and 4 in STANDBY Gas Setup: ---------- fill B-top 6psi D2 Hybrid enabled (PG4) fill B-side lower 1 psi Argon Hybrid Disabled (PG1) fill B-side Upper as is, Hybrid Disabled (PG2) fill B-main 40psi D2 Hybrid Enabled (PG3) NINJA: 12psi D2 Enable ECE, VUV, Z-bolo shutter assuming no vacuum problems Physop plan (Wolfe to start): ----------------------- Parker will probably be in after 9:15 or so. If the LH group and co-session leader are ready to go at 9:00, start with seg1 from a good shot from Wednesday, with PG4 puff at 18ms or longer. Seg2 should be as on 1060310024 (nl_04~0.6, B0=5.4 T, and Ip~ 700kA). SL_Plan calls for essentially constant plasma programming all day. ************************************************************** As of this writing, OVERNIGHT BORONIZATION is scheduled for Thursday night. There will be limited access following the run, following which the cell, power room and labs will be locked out until Friday morning. ************************************************************** |
| Session Leader Summaries |
| Entered: Apr 6 2006 08:23:57:260PM |
| Author: John Liptac |
| Protection system was tested raising issues that need to be addressed. In general this approach for the protection seems promising, but needs a bit more time to iron out some bugs.
The day began with the trip level set to 10% of the RINT/FINT value at the intermediate coupler. Power demand was set at 20kW/klystron to begin with using 5 ms pulses. The trip level was set at too low a level as there was a nuisance trip on the first shot. A long cell access was needed to change the trip level to 30%. There were then issues with a bad cable on a FINT, this was replaced and testing continued. The power level was increased incrementally until an arc or high reflection coefficient was produced. Shot 7 had an arc at 50kW/klystron, which the protection failed to detect. Another long cell access was needed to investigate the failure. All boards except 9 and 10 seemed to be working properly. Shot 7 had an arc on 10. The problem seems to be related to CPCI backplane wire routing. It was determined that more time would be needed to fix this issue so the last three shots of the day were used to gather more coupling data. Brambilla analysis of previous data indicates the presence of a vacuum gap. The launcher was moved in further, to 1596, which is ~1mm behind the LH limiter. Phase scans using six segments with 60,90,120,150,180,90 CD phasing were used to match results obtained from run 1060307. Moving the launcher in reduced the reflection coefficient as was expected. Shot 8 only made it through 4/6 phase segments due to the high reflection from 180 degree phasing. The protection system was bypassed for the last two shots. Shot 9 matched conditions from 1060307, while shot 10 had double the density to try and decrease the reflection coefficient even further, which it did. |
| Physics Operator Summaries |
| Entered: Apr 6 2006 05:26:08:727PM |
| Author: Ron Parker |
| The run was devoted to commisioning the coupler protection system for the LH experiment. Two channels (out of 12) did not function properly and this prevented raising the power higher than in the last run. RF breakdown was observed at the ~50 kW per klystron level (measured at the intermediate couplers.) The pulses were kept short (5 ms) in order to avoid large energy dissipation in the event of an arc. Although a large fraction of the run was devoted to trouble shouting the CPS, it was not possible to fix it. Late in the day (~ 4:00) the SL's decided to forego further trouble shouting and finish the run by filling in more points on the reflection coeficient vs. density.
The machine ran without trouble. 11 shots were fired off, 10 were full length plasmas and 1 was a power test. There were no fizzles, no duds and no disruptions except in one shot during rampdown when a pellet was injected late in the discharge. |
| Session Leader Comments | |||
| Apr 6 2006 09:25:46:390AM | 1060406001 | John Liptac | Test of LH protection system using the ratio of RINT/FINT signals. Threshold is set for about 10%, which may be too low (wanted ~20%). Try it at this level and if it trips out, then the level will have to be adjusted, which would mean an extended cell access.
Trips. Try another shot with cps bypassed to see if we can make it through the shot. |
| Apr 6 2006 09:31:54:220AM | 1060406002 | John Liptac | CPS bypassed shot went through. Need cell access to adjust trip level.
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| Apr 6 2006 12:18:00:993PM | 1060406003 | John Liptac | Trip level increased to 30%. The gate was also changed on the protection system to disregard the noise present on startup.
No power shot. Data system problem. Shot count didn't increment. So shot 3 no trip, signals look ok. RINT/FINT values not calibrated to power. FINT6 ans FINT12 look pretty low now. RINT levels are only slightly reduced on these two channels. |
| Apr 6 2006 12:27:27:977PM | 1060406004 | John Liptac | Go to two pulses 5ms 50 ms apart at 30 kw/klystron. No trips. FINT12 doesn't look good reading ~1kW.
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| Apr 6 2006 12:47:27:603PM | 1060406005 | John Liptac | Two pulses 5ms 50 ms apart at 40 kw/klystron. No protection on 12 since FINT isn't working properly, turn it off and continue.
No trips, but the noise on FINT12 is close to tripping out given the signal on RINT12. |
| Apr 6 2006 01:30:24:743PM | 1060406006 | John Liptac | Cell access to check board connection on FINT12. Bad cable fixed should work. FINT6 might work better as well.
LH into dummy loads. 5ms at 50 kw/klystron. 12 and 6 look good now. |
| Apr 6 2006 04:25:51:337PM | 1060406007 | John Liptac | Two pulses 5ms 50 ms apart at 50 kw/klystron. Pulse one should have tripped the system and did not. RINT/FINT ratio ~50% on klystron 10. Second pulse looked fine.
Nothing visible on LH camera. Issue on boards for 9 and 10. |
| Apr 6 2006 04:54:13:413PM | 1060406008 | John Liptac | Protection system will require further investigation.
Revisit coupling studies. Brambilla analysis of previous data indicates the presence of a vacuum gap. Try moving couper in further to see if this gap may be reduced or eleminated. Coupler position set to 1596, grill approx 1mm behind LH limiter. Six segments 60, 90, 120, 150, 180, 90 degree CD phasing at 20kW/klystron. 180 shot length, 33% DC, 30ms pulse length. Start time 0.7 s. Fault on 180 degree pulse, where the reflection coef should be ~50% Bypass and repeat to get all pulses. |
| Apr 6 2006 04:55:40:307PM | 1060406009 | John Liptac | Coupler position set to 1596, grill approx 1mm behind LH limiter.
Six segments 60, 90, 120, 150, 180, 90 degree CD phasing at 20kW/klystron. 180 shot length, 33% DC, 30ms pulse length. Start time 0.7 s. Got all data this shot. Lowered refelction coefficient. Try and increase density by factor of 2 next shot. |
| Apr 6 2006 05:05:47:040PM | 1060406010 | John Liptac | Coupler position set to 1596, grill approx 1mm behind LH limiter.
Six segments 60, 90, 120, 150, 180, 90 degree CD phasing at 20kW/klystron. 180 shot length, 33% DC, 30ms pulse length. Start time 0.7 s. Got all data this shot. Increased density lowers reflection coef. |
| Physics Operator Comments | |||
| Apr 6 2006 07:49:34:047AM | Steve Wolfe | Setting up for Run 1060406. Parker will take over when he gets in after 9:00AM Start from 1060405029. Import Seg_02 from 1060310024 Ip=700kA, NL04=4e19, no pg3 maint level, no pg1 Just for cosmetics, remove sweeps from V_17 (AMHD FREQ) and negative puff waveform on V_19 (Diborane Piezo) In Seg_01: Change PG4 from 18ms to 20ms Change IC_EF4U from -1350 to -1340 Load/Clean Load at 6-Apr-2006 07:43:55.00 Open tree /home/wolfe/pcs_scratch -1 Open tree done Sign in as Physop and watch as the sign-in window blows away the previous entry of this posting before I have a chance to enter it in logbook. Retype it and Make Entry. | |
| Apr 6 2006 08:28:44:547AM | Steve Wolfe | Forgot I had a live PCS up and opened a new one from the cvswork code. Blew it away before changing anything, but I'll reload the live one before proceeding, just to be sure. Remember to unset pcs_scratch in my other session before bringing it up again. | |
| Apr 6 2006 09:08:20:297AM | 1060406001 | Steve Wolfe | Shot#1: Before shot, have Bill set TF invert time back to 1.6 instead of 3.8sec (old shot had a backporch; we're not doing that now). Parker's here. He'll sign in and take over. Still waiting for LH to be ready |
| Apr 6 2006 09:27:21:390AM | 1060406001 | Ron Parker | Shot 1 ran well, thanks to Steve.
Good breakdown (5 ms) and smooth current rise. Gas prefill ~ 0.045 T Density is low, n_el(4) ~ 0.3. LHRF tripped out, CPS set to trip on 10% reflection. One more shot with CPS bypassed to test system. Then we will have a cell access to set CPS to ~ 30% reflected. |
| Apr 6 2006 09:58:45:197AM | 1060406001 | Steve Wolfe | Shot#1: Before shot, have Bill set TF invert time back to 1.6 instead of 3.8sec (old shot had a backporch; we're not doing that now). Parker's here. He'll sign in and take over. Still waiting for LH to be ready |
| Apr 6 2006 09:40:17:877AM | 1060406002 | Ron Parker | Shot 2 looked good, RF ran for 5 ms with CPS bypassed.
There will now be some delay. CPS boards will be pulled to desensitize the trip level to 30% reflected power. Pulling the boards will not take long, but we will do a diborane leak check as well. When complete, we will resume shots. Total delay may last one hour. |
| Apr 6 2006 10:53:19:057AM | 1060406002 | Ron Parker | Still working on diborane problem and resetting trip levels on CPS boards.
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| Apr 6 2006 11:36:58:163AM | 1060406002 | Steve Wolfe | Shot#3: Parker at class. Wolfe back in again. LH claims they're ready. |
| Apr 6 2006 11:46:15:010AM | 1060406003 | Steve Wolfe | Shot#3: No PCS changes since last shot. Machine has been up to helium a couple of times and back down, during work on diborane piezo valve. Base pressure is 1.7e-7. No power shot- dispatcher hung up going to INIT |
| Apr 6 2006 12:04:17:867PM | 1060406003 | Steve Wolfe | Shot#3 second time: Increase pg4 from 20 to 22msec, since we've been sitting so long and both earlier shots bounced. Parker back, but I'll take responsibility for this one. plasma, still some runaways. Parker's problem now Note: The previous no-power cycle apparently did not increase the shot counter, so this was the OFFICIAL shot 3 |
| Apr 6 2006 12:08:37:133PM | 1060406003 | Ron Parker | Shot 3 (2nd try) ran and LHRF fired without faulting.
Power 20 kW/klystron at the FINT's. IC_EF4 increased by 10 kA for next shot, from -1340 to -1330 A. LHRF power will be increased to 30 kW at the FINTs, for two 5 ms pulses spaced 100 ms apart. |
| Apr 6 2006 12:46:59:210PM | 1060406004 | Ron Parker | Shot 4 ran well.
Next: increase power to 40 kW/klystron. Turn off 12 which is not reading correctly on the RINT and FINT. |
| Apr 6 2006 12:48:33:307PM | 1060406005 | Ron Parker | Shot 5 ran OK, LHRF set at 40, ran ~ 30 kW/klystron |
| Apr 6 2006 12:51:45:273PM | 1060406005 | Ron Parker | Cell access to jiggle card in channel 12 cps. |
| Apr 6 2006 01:25:25:900PM | 1060406006 | Ron Parker | Shot 6 ran OK. LHRF ran into dummy load to test RINTs and FINTS.
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| Apr 6 2006 02:07:11:023PM | 1060406007 | Ron Parker | Shot 7 ran OK. LHRF ~ 40 kW/klystron.
Problem in klystron 10, WGs 19 and 20. High reflected coefficient, ~ 50%, but RF pulse did not shut down. Cell acccess to trouble shout. |
| Apr 6 2006 04:49:15:383PM | 1060406008 | Ron Parker | Shot 8 finally ran after another long delay to trouble shout the LH CPS.
Problem found, but not enough time to fix. Shot actually triggered working LH CPS after 4 out of 6 pulses @ 20 kW/klystron. |
| Apr 6 2006 04:55:54:913PM | 1060406009 | Ron Parker | Shot ran well, no pellet, no disruption.
One last shot coming up with higher density, from ~.4 on last shot to .8 (n_el(4)). |
| Apr 6 2006 05:11:16:273PM | 1060406010 | Ron Parker | Shot 10 ran with the requested density.
The last few shots were useful to complement coupling data obtained in previous run. |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 09:13:28:830AM | Plasma | Ok | |
| 2 | 09:26:02:593AM | Plasma | Ok | |
| 3 | 11:57:35:883AM | Plasma | Ok | |
| 4 | 12:18:47:790PM | Plasma | Ok | |
| 5 | 12:33:47:510PM | Plasma | Ok | |
| 6 | 01:23:09:837PM | Plasma | Ok | |
| 7 | 01:45:01:117PM | Plasma | Ok | |
| 8 | 04:34:39:633PM | Plasma | Ok | |
| 9 | 04:47:49:227PM | Plasma | Ok | |
| 10 | 05:00:15:587PM | Plasma | Ok | |