| Miniproposals | ||||||||||||
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| Operators | |
| Session leader(s): | Yuichi Takase,Steve Horne |
| Physics operator(s): | Robert Granetz |
| Engineering operator(s): | Vinny Bertolino |
| Engineering Operator Run Comment |
| Session Leader Plans |
| Physics Operators Plans |
| Session Leader Summaries |
| Physics Operator Summaries |
| Entered: Jul 7 2004 04:36:52:817PM |
| Author: To Be Determined |
| Physics operator's run summary for 950106 SL: Yuichi Takase PO: R. Granetz EL: V. Bertolino GOAL: condition E-port antenna PIGGYBACK: Increase plasma elongation to test the (hopefully) faster EFC response. (Steve Horne). RESULTS: The RF had severe arcing problems, probably somewhere in the tuners. The problems were bad enough to lead to an early cessation of the run in order to allow for debugging and repairs. The piggyback goal was carried out successfully, with the final shot having an elongation of 1.73 and a centroid on the midplane. MISCELLANEOUS: EF1L is having a difficult time following its demand, and this resulted in two duds early in the run. We managed to work around this, but the problem needs some looking into. There was another dud due to a fault in EF4. There were 4 fizzles (probably due to Ip rising too fast) and a lot of shots had early hard x-rays. Both of these are thought to be indications of a very clean machine, although the base pressure did not go below 1.6e-6 torr. TALLY: 13 Plasmas 4 Fizzles 3 Duds (power supply problems) SPECIAL NOTE: There were no disruptions in this run. Detailed shot-by-shot account follows: Plan: start with shot 950104009 and repeat it over and over again. This shot is a typical diverted plasma, with Ip=0.6 MA and nl_04=0.8e20 m-2. There were a couple of hours of ECDC prior to this run. Base pressure at 10 minutes prior to start of run is 9e-7 torr. Set pre-fill at 1.4e-5 torr. Shot 001: Plasma. Nice shot. Density control is excellent. Plasma position is at -1.3 cm (x-ray centroid). Antenna E had multiple pulses up to 0.8 MW. This is a very satisfactory target plasma for the RF conditioning goals. For next shot, tweak chopper pre-programmed bias voltage after t=0 from V=0 to V=+200 volts (requested by Steve Horne.) Shot 002: Dud. EF1L had overshooting problem. Next shot: increase nl from 0.8 to 1.0e20 m-2. Also change EF1L voltage programming from -60 to -50 volts prior to t=0. Shot 003: Dud. EF1L is having some problems getting to the demand current prior to t=0. Next shot, tweak EF1L current programming (in segment 01). Shot 004: Plasma. Nice shot. EF1L is still not following demand. RF was only at a few kW. Next shot: push back EF1U & L start and close times by 0.1 s, and adjust voltage and current programming demands accordingly. Shot 005: Fizzle. (50 kA) Next shot: decrease fast ZCUR derivative gain (requested by Steve Horne). Otherwise, just do a repeat. Shot 006: Plasma. This higher density (nl=1.0e20 m-2) is resulting in detachment during the current ramp. There are also some hard x-rays early in the shot. Prf up to 0.6 MW. Next shot: program density to come down faster (but still starting at 0.8 s, as before), and raise the pre-fill from 1.4 to 1.5e-5 torr. Shot 007: Plasma. Still had detachment during rampdown (after 1.2 s) and hard x-rays early. RF got to 0.3-0.4 MW. Next shot: raise pre-fill again (1.5 to 1.6e-5 torr), and start density rampdown 50 ms earlier. Shot 008: Plasma. Still had detachment, perhaps a touch later (1.23 s), and there were still (a lower) level of hard x-rays. Next shot: tweak up the pulse gas voltage early in the shot, and (for Steve Horne) turn on the fast ZCUR on wire 10 and turn off the fast ZCUR on wire 03. We also increased the derivative gain and decreased the proportional gain. Shot 009: Dud. Caused by EF4 faulting at -0.7 s. Next shot: no changes. Shot 010: Plasma. No hard x-rays (finally). Still had detachment late in the rampdown. RF had many, many faults and restrikes. Next shot: increase fast ZCUR derivative gain again from 1.2 to 1.5. Steve Horne thinks the zcentroid is more stable on shot 10 than on shot 9. Shot 011: Plasma. Same as previous shot. RF is having problems. Next shot: decrease density from nl=1.0e20 to 0.8e20 m-2. Shot 012: Fizzle. Next shot: repeat with no changes. Shot 013: Plasma. Hard x-rays early in the shot. RF is having problems. Next shot: increase density from nl=0.8e20 to nl=1.2e20 m-2, and tweak the pulse gas voltage up a little early in the shot, and increase fast ZCUR derivative gain and decrease fast ZCUR proportional gain. Shot 014: Plasma. Hard x-rays early. RF having problems. Next shot: increase pulse gas voltage early. Also change chopper voltage programming (requested by Steve Horne). Shot 015: Plasma. Hard x-rays early. These higher density shots have all detached late in the current rampdown. RF having problems. Next shot: move the entire pulse gas voltage programming earlier by 1 ms, and decrease the fast ZCUR derivative gain by a factor of 2. Shot 016: Fizzle. It's not an obvious "bouncer" on the polychromator...could be overgassed by the 1 ms shift in pulse gas programming. Next shot: repeat with no changes Shot 017: Plasma. Lots of hard x-rays early. RF having problems. Next shot: move entire pulse gas voltage programming earlier by another millisecond. Also lower ZXL by 1 cm. Shot 018: Fizzle. 50 kA. Protoplasma moved outwards. Next shot: increase pre-fill from 1.6 to 1.7e-5 torr and repeat. Shot 019: Plasma. No hard x-rays (finally). The elongation was slightly higher (1.62) since ZXL was lowered by 1 cm. Next shot: ramp the Z-centroid from -1.5 cm to 0.0, which will be a good test of the "supposedly" faster EFC capability. Shot 020: Plasma. Z-centroid moved from -1.5 cm to 0.0, without losing vertical position control, although EFC almost railed. The elongation reached 1.73, with the plasma centered at the midplane. Because of the problems with the RF, and given the successful completion of the piggyback goal of exercising the faster EFC response, and the fact the EF1L needs some looking into, we are going to stop the run now (at 14:10), so that repairs can be made. |
| Session Leader Comments |
| Physics Operator Comments | |||
| Jan 6 1995 02:15:03:060PM | Robert Granetz | SL: Yuichi Takase
PO: R. Granetz EL: V. Bertolino Goal: condition E-port antenna Piggyback goal (Steve Horne): increase plasma elongation to test the (hopefully) faster EFC response. Plan: start with shot 950104009 and repeat it over and over again. This shot is a typical diverted plasma, with Ip=0.6 MA and nl_04=0.8e20 m-2. There were a couple of hours of ECDC prior to this run. Base pressure at 10 minutes prior to start of run is 9e-7 torr. Set pre-fill at 1.4e-5 torr. | |
| Jan 6 1995 08:57:08:880AM | 950106001 | Robert Granetz | Plasma. Nice shot. Density control is excellent. Plasma position
is at -1.3 cm (x-ray centroid). Antenna E had multiple pulses up to 0.8 MW. This is a very satisfactory target plasma for the RF conditioning goals. For next shot, tweak chopper pre-programmed bias voltage after t=0 from V=0 to V=+200 volts (requested by Steve Horne.) |
| Jan 6 1995 09:13:41:850AM | 950106002 | Robert Granetz | Dud. EF1L had overshooting problem.
Next shot: increase nl from 0.8 to 1.0e20 m-2. Also change EF1L voltage programming from -60 to -50 volts prior to t=0. |
| Jan 6 1995 09:28:59:030AM | 950106003 | Robert Granetz | Dud. EF1L is having some problems getting to the demand current prior
to t=0. Next shot, tweak EF1L current programming (in segment 01). |
| Jan 6 1995 09:49:33:840AM | 950106004 | Robert Granetz | Plasma. Nice shot. EF1L is still not following demand. RF was only
at a few kW. Next shot: push back EF1U & L start and close times by 0.1 s, and adjust voltage and current programming demands accordingly. |
| Jan 6 1995 10:00:45:160AM | 950106005 | Robert Granetz | Fizzle. (50 kA)
Next shot: decrease fast ZCUR derivative gain (requested by Steve Horne). Otherwise, just do a repeat. |
| Jan 6 1995 10:11:52:130AM | 950106006 | Robert Granetz | Plasma. This higher density (nl=1.0e20 m-2) is resulting in detachment
during the current ramp. There are also some hard x-rays early in the shot. Prf up to 0.6 MW. Next shot: program density to come down faster (but still starting at 0.8 s, as before), and raise the pre-fill from 1.4 to 1.5e-5 torr. |
| Jan 6 1995 10:29:29:630AM | 950106007 | Robert Granetz | Plasma. Still had detachment during rampdown (after 1.2 s) and hard
x-rays early. RF got to 0.3-0.4 MW. Next shot: raise pre-fill again (1.5 to 1.6e-5 torr), and start density rampdown 50 ms earlier. |
| Jan 6 1995 10:52:19:900AM | 950106008 | Robert Granetz | Plasma. Still had detachment, perhaps a touch later (1.23 s), and there
were still (a lower) level of hard x-rays. Next shot: tweak up the pulse gas voltage early in the shot, and (for Steve Horne) turn on the fast ZCUR on wire 10 and turn off the fast ZCUR on wire 03. We also increased the derivative gain and decreased the proportional gain. |
| Jan 6 1995 11:08:16:630AM | 950106009 | Robert Granetz | Dud. Caused by EF4 faulting at -0.7 s.
Next shot: no changes. |
| Jan 6 1995 11:37:55:540AM | 950106010 | Robert Granetz | Plasma. No hard x-rays (finally). Still had detachment late in the
rampdown. RF had many, many faults and restrikes. Next shot: increase fast ZCUR derivative gain again from 1.2 to 1.5. Steve Horne thinks the zcentroid is more stable on shot 10 than on shot 9. |
| Jan 6 1995 11:46:06:550AM | 950106011 | Robert Granetz | Plasma. Same as previous shot.
Next shot: decrease density from nl=1.0e20 to 0.8e20 m-2. |
| Jan 6 1995 11:57:59:410AM | 950106012 | Robert Granetz | Fizzle.
Next shot: repeat with no changes. |
| Jan 6 1995 12:15:19:100PM | 950106013 | Robert Granetz | Plasma. Hard x-rays early in the shot.
Next shot: increase density from nl=0.8e20 to nl=1.2e20 m-2, and tweak the pulse gas voltage up a little early in the shot, and increase fast ZCUR derivative gain and decrease fast ZCUR proportional gain. |
| Jan 6 1995 12:24:37:440PM | 950106014 | Robert Granetz | Plasma. Hard x-rays early.
Next shot: increase pulse gas voltage early. Also change chopper voltage programming (requested by Steve Horne). |
| Jan 6 1995 12:42:42:420PM | 950106015 | Robert Granetz | Plasma. Hard x-rays early. These higher density shots have all
detached late in the current rampdown. Next shot: move the entire pulse gas voltage programming earlier by 1 ms, and decrease the fast ZCUR derivative gain by a factor of 2. |
| Jan 6 1995 01:02:03:990PM | 950106016 | Robert Granetz | Fizzle. It's not an obvious "bouncer" on the polychromator...could
be overgassed by the 1 ms shift in pulse gas programming. Next shot: repeat with no changes |
| Jan 6 1995 01:13:46:940PM | 950106017 | Robert Granetz | Plasma. Lots of hard x-rays early. RF having problems.
Next shot: move entire pulse gas voltage programming earlier by another millisecond. Also lower ZXL by 1 cm. |
| Jan 6 1995 01:27:06:270PM | 950106018 | Robert Granetz | Fizzle. 50 kA. Protoplasma moved outwards.
Next shot: increase pre-fill from 1.6 to 1.7e-5 torr and repeat. |
| Jan 6 1995 01:41:23:720PM | 950106019 | Robert Granetz | Plasma. No hard x-rays (finally). The elongation was slightly higher
(1.62) since ZXL was lowered by 1 cm. Next shot: ramp the Z-centroid from -1.5 cm to 0.0, which will be a good test of the "supposedly" faster EFC capability. |
| Jan 6 1995 02:10:35:330PM | 950106020 | Robert Granetz | Plasma. Z-centroid moved from -1.5 cm to 0.0, without losing vertical
position control, although EFC almost railed. The elongation reached 1.73, with the plasma centered at the midplane. Because of the problems with the RF, and given the successful completion of the piggyback goal of exercising the faster EFC response, and the fact the EF1L needs some looking into, we are going to stop the run now (at 14:10), so that repairs can be made. |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 08:43:25:880AM | Plasma | Ok | no faults |
| 2 | 08:57:49:740AM | Plasma | Ok | no faults |
| 3 | 09:15:05:180AM | Plasma | Ok | no faults |
| 4 | 09:30:01:360AM | Plasma | Ok | no faults |
| 5 | 09:51:17:060AM | Plasma | Ok | no faults |
| 6 | 10:02:16:130AM | Plasma | Ok | no faults |
| 7 | 10:19:14:210AM | Plasma | Ok | no faults |
| 8 | 10:37:36:790AM | Plasma | Ok | no faults |
| 9 | 11:04:15:520AM | Plasma | Bad | ef4a unsched. output |
| 10 | 11:24:45:710AM | Plasma | Ok | no faults |
| 11 | 11:39:27:950AM | Plasma | Ok | no faults |
| 12 | 11:52:05:400AM | Plasma | Ok | no faults |
| 13 | 12:02:24:940PM | Plasma | Ok | no faults |
| 14 | 12:17:19:020PM | Plasma | Ok | no faults |
| 15 | 12:31:43:890PM | Plasma | Ok | no faults |
| 16 | 12:52:30:680PM | Plasma | Ok | no faults |
| 17 | 01:04:53:690PM | Plasma | Ok | Plasma shot O.K. |
| 18 | 01:17:11:860PM | Plasma | Ok | No Faults. |
| 19 | 01:30:49:300PM | Plasma | Ok | No faults. |
| 20 | 01:50:23:990PM | Plasma | Ok | No faults. |