| Miniproposals | ||||||||||||
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| Operators | |
| Session leader(s): | Yijun Lin,Steve Wukitch |
| Physics operator(s): | Dmitri Mossessian |
| Engineering operator(s): | Bill Parkin,Bill Cochran |
| Engineering Operator Run Comment |
| RF Conditioning, S.Wukitch/Y.Lin/Mossessian/Cochran/Parkin. |
| Session Leader Plans |
| Physics Operators Plans |
| Session Leader Summaries |
| Entered: Jul 7 2004 03:49:29:757PM |
| Author: To Be Determined |
| Engineering setup for Tuesday 13 Aug 2002 Session leader: S. Wukitch, Y. Lin Physics operator: D. Mossessian ECDC in the morning, if possible, stopping by 07:00. Set up for possible ECDC in D2 between shots. Run begins at 09:00 and ends at 17:00. For the beginning of plasma operation, set up power systems as on 1020808025, which was a limited plasma (for the RF...no H-modes) Gas setup: fill B-Top with 6 psi D2 Hybrid enabled (PG4) fill B-side lower with 1 psi Ar Hybrid enabled (PG1) fill B-side upper with 10 psi D2 Hybrid DISABLED (PG2) (for ECDC) fill C-side with 30 psi D2 Hybrid enabled (PG3) leave J-Bottom as is Hybrid DISABLED (PG5) Enable the following gate valves, assuming no vacuum problems: ECE, VUV, DNB ------------------------------------------------------------------------------- RF Setup: FMIT#2,3&4 transmitters in Run On by 07:00. ------------------------------------------------------------------------------- Run Plan: Work on E and J systems into plasma. Start by loading segment 2 from 1020808022 (limiter plasma)and let the RF go at it. We may switch to a diverted shot later in the day. ------------------------------------------------------------------------------- 001 request: inner wall limited Ip~0.8 MA, BT~4.6 T, nl_04~1x10^20 m^-2 D: off E: 1.0 MW ramp @[1.0,1.5]sec J: 1.0 MW ramp @[0.6-1.5]sec result: plasma E: 1.0 MW good J: 1.0 MW with a couple of faults (DC1 arc detect mostly) action: retune J a bit and raise power on E 002 request: inner wall limited Ip~0.8 MA, BT~4.6 T, nl_04~1x10^20 m^-2 D: off E: 1.1 MW ramp @[1.0,1.5]sec J: 1.0 MW ramp @[0.6-1.5]sec result: fizzle OH2U commutation delay action: 003 request: inner wall limited Ip~0.8 MA, BT~4.6 T, nl_04~1x10^20 m^-2 D: off E: 1.1 MW ramp @[1.0,1.5]sec J: 1.0 MW ramp @[0.6-1.5]sec result: plasma E: 1.1 MW clean J: 1.0 MW two faults action: raise both to 1.2 MW 004 request: inner wall limited Ip~0.8 MA, BT~4.6 T, nl_04~1x10^20 m^-2 D: off E: 1.2 MW ramp @[1.0,1.5]sec J: 1.2 MW ramp @[0.6-1.5]sec result: plasma - early disruption 005 request: power system test 006 request: inner wall limited Ip~0.8 MA, BT~4.6 T, nl_04~1x10^20 m^-2 D: off E: 1.2 MW ramp @[1.0,1.5]sec J: 1.2 MW ramp @[0.6-1.5]sec result: fizzle 007 request: inner wall limited Ip~0.8 MA, BT~4.6 T, nl_04~1x10^20 m^-2 D: off E: 1.2 MW ramp @[1.0,1.5]sec J: 1.2 MW ramp @[0.6-1.5]sec result: E: 1.2 MW clean J: 1.2 MW max faults Arc in the pulse forming network for OH2U commutation occurred during the discharge. Repairs are required; thus, the run is over. Summary: Before operations, the J-port phase control was investigated and the problem with the control was traced to the feedback signal's limiter amplifier. This amplifier produced a -8 dbm noise signal when there was no feedback signal resulting in the VCO starting with a frequency 30 kHz off the 30 MHz free-running frequency and out of the capture range of the PLL. The limiter was by-passed resulting in ~3 msec locking time. This time was further reduced by trimming the phase of the feedback signal to approximately the phase of the carrier leak signal. The resulting locking time was reduced < 1 msec. Vacuum conditioning tests showed the setup was fine and J was conditioned up to 37 kV. During operation, we noticed that J-port often failed to restart when run simultaneously with E-port after a fault. The coupled power from E-port caused a similar problem as the amplifier (the 80 MHz signal caused the VCO starting frequency to be out of capture range). A filter was installed on the feedback lines that reduced the coupled power at 80 MHz and 80.5 MHz by 20 dB. In addition a 100 MHz low pass filter was installed and the phase of the feedback signal was re-trimmed. D-port antenna is out of service until further notice. The transmitter power supplies (Uptegraff 30 kV, 180 A transformer rectifiers) were tested recently as part of maintenance proceedures. The oil was tested for dissolved gases that could indicate possible arcing problems. D-port's supply indicated high levels of acetylene and H suggesting some arcing or severe overheating has occurred. Although the supply appeared to be working fine, the Uptegraff engineer felt it was prudent to do an inspection before continuing operation. The inspection begin on Wedensday and take until Friday. A straight replacement for this supply is ~200k. |
| Physics Operator Summaries |
| Session Leader Comments | |||
| Aug 13 2002 09:20:44:470AM | 1020813001 | Steve Wukitch | 001 request: inner wall limited Ip~0.8 MA, BT~4.6 T, nl_04~1x10^20 m^-2 D: off E: 1.0 MW ramp @[1.0,1.5]sec J: 1.0 MW ramp @[0.6-1.5]sec result: plasma E: 1.0 MW good J: 1.0 MW with a couple of faults (DC1 arc detect mostly) action: retune J a bit and raise power on E |
| Aug 13 2002 10:11:02:347AM | 1020813002 | Steve Wukitch | 002 request: inner wall limited Ip~0.8 MA, BT~4.6 T, nl_04~1x10^20 m^-2 D: off E: 1.1 MW ramp @[1.0,1.5]sec J: 1.0 MW ramp @[0.6-1.5]sec result: fizzle OH2U commutation problem |
| Aug 13 2002 10:12:31:377AM | 1020813003 | Steve Wukitch | 003 request: inner wall limited Ip~0.8 MA, BT~4.6 T, nl_04~1x10^20 m^-2 D: off E: 1.1 MW ramp @[1.0,1.5]sec J: 1.0 MW ramp @[0.6-1.5]sec result: plasma E: 1.1 MW clean J: 1.0 MW two faults action: raise both to 1.2 MW |
| Aug 13 2002 10:32:11:813AM | 1020813004 | Steve Wukitch | 004 request: inner wall limited Ip~0.8 MA, BT~4.6 T, nl_04~1x10^20 m^-2 D: off E: 1.2 MW ramp @[1.0,1.5]sec J: 1.2 MW ramp @[0.6-1.5]sec result: plasma - early disruption |
| Aug 13 2002 11:53:58:127AM | 1020813005 | Steve Wukitch | 005 request: power system test |
| Physics Operator Comments | |||
| Aug 13 2002 08:29:46:767AM | Dmitri Mossessian | Plan - RF conditionning Engineering setup for Thursday 08 Aug 2002 Session leader: S. Wukitch, Y. Lin Physics operator: D. Mossessian Gas setup: fill B-Top with 6 psi D2 Hybrid enabled (PG4) fill B-side lower with 1 psi Ar Hybrid enabled (PG1) fill B-side upper with 10 psi D2 Hybrid DISABLED (PG2) (for ECDC) fill C-side with 30 psi D2 Hybrid enabled (PG3) leave J-Bottom as is Hybrid DISABLED (PG5) Enable the following gate valves, assuming no vacuum problems: ECE, VUV, DNB Start with shot 1020808022 - 4.68 T, tweek Bt to get to 4.6 T. Load segment 2 from 1020808022 8:25 Coldstart OK | |
| Aug 13 2002 10:26:54:157AM | 1020813001 | Dmitri Mossessian | Plasma. Current rize is a little slow, but we will not change anything. Next shot - no changes |
| Aug 13 2002 10:27:08:360AM | 1020813002 | Dmitri Mossessian | Fizzle. OH2-upper problem |
| Aug 13 2002 10:27:24:360AM | 1020813003 | Dmitri Mossessian | Plasma. Current rise is too fast for Bz. For next shot - Bz up: IC_EF4 -1325 -> -1315 |
| Aug 13 2002 10:27:43:300AM | 1020813004 | Dmitri Mossessian | Plasma. Startup OK For next shot - no changes |
| Aug 13 2002 11:48:03:847AM | 1020813005 | Dmitri Mossessian | EF2_upper test |
| Aug 13 2002 01:54:33:453PM | 1020813006 | Dmitri Mossessian | Week fizzle - power supply problems |
| Aug 13 2002 01:55:14:297PM | 1020813007 | Dmitri Mossessian | Plasma. End of run. |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 09:11:20:737AM | Plasma | Ok | |
| 2 | 09:28:02:470AM | Plasma | Bad | OH2U Commutation Fault |
| 3 | 10:06:10:627AM | Plasma | Ok | |
| 4 | 10:19:20:953AM | Plasma | Ok | |
| 5 | 11:48:19:063AM | Test | Ok | EF2U Test |
| 6 | 12:07:00:190PM | Plasma | Bad | OH2U comm problem |
| 7 | 01:14:16:643PM | Plasma | Bad | OH2U comm fault failure |