| Miniproposals | ||||||||||
|
| Operators | |
| Session leader(s): | Spencer Pitcher |
| Physics operator(s): | Ian Hutchinson |
| Engineering operator(s): | Frank Silva |
| Engineering Operator Run Comment |
| MP230 Flappers/Hutch/Silva |
| Session Leader Plans |
| Physics Operators Plans |
| Session Leader Summaries |
| Entered: Jul 7 2004 03:49:19:743PM |
| Author: To Be Determined |
| Run Summary for 990302 MP 230 Effect of Divertor Baffling on Confinement, Thresholds and the ELM-free/EDA Boundary Session Leader: S Pitcher Phys Op : I Hutchinson Purpose: The purpose of this experiment was to investigate the effect of divertor baffling on confinement, H-mode thresholds and the ELM-free/EDA boundary. Conditions in the pedestal/edge region were carefully monitored. Summary: The machine did not run well today. The machine showed signs of 'running out of boronization', ie unreliable EDA's at 1.5 MW and moly in the plasma. No steady-state EDA's were achieved. Nevertheless, some crude comparisons could be made between discharges with flappers closed for the whole shot vs others open for the whole shot. Comparing shots 12 (closed) and 13 (open) for example, the divertor neutral pressure is approx a factor of 2 lower with flappers open. In contrast, within error the following are not affected by the flapper, fside midplane pressure, Wmhd and Halpha. Later we tried to do threshold studies using an RF power ramp (shots >=17). Unfortunately, the flapper power supply started to act up and we got no threshold comparisons re flapper closed/open. Conclusions: The indications are that the flapper influences the divertor neutral pressure in Ohmic and H-mode, reducing it by ~ 2 when open. Main chamber neutrals are not strongly affected, nor is confinement. These results are preliminary, as better comparison discharges are still needed. Can't say much about thresholds at this point. A new boronization is needed (tonight). |
| Physics Operator Summaries |
| Entered: Jul 7 2004 04:37:00:350PM |
| Author: To Be Determined |
| MP 230 Flappers and H-mode Summary _______ The object today was originally to get steady EDA H-modes and then see the effects of the flappers open or closed on confinement. This was not accomplished because of technical problems. Some information about the power threshold (non)influence of the flappers was obtained. The first couple of hours were lost to a disk corruption affecting the models disk and clobbering MDSplus. EF1L was misbehaving with a ~100V offset relative to its hybrid demand. Engineers worked on it and it fixed itself after a while but without strong confidence that it will stay fixed. RF transmitter one did not run reliably today; so power was limited to 1.5 MW max from the other. This was insufficient to obtain H-modes that avoided impurity accumulation, though there was some degree of D-alpha enhancement. Radiation was rising rapidly during the H-mode and led to a reversion to L-mode. The last 3 shots 17-19 were devoted to a power ramp for threshold. This seemed to indicate that the flappers had no discernible effect on the threshold power at nl04=1.e20. Scorecard _________ Shot,Duration(s),Ipmax(MA) Shot,Duration(s),Ipmax No Ip 1 2 0.000 0.005 3 0.000 0.021 4 0.000 0.027 5 1.673 0.782 6 1.693 0.786 7 1.686 0.787 8 0.000 0.034 9 1.703 0.792 10 1.700 0.797 11 1.701 0.802 12 1.656 0.802 13 1.684 0.807 14 1.682 0.807 15 1.672 0.802 16 1.678 0.812 17 1.661 0.792 18 1.672 0.792 19 1.654 0.792 Finished summary for 990302 Total of 19 shots. 19 shots. 14 plasmas. 2 fizzles. 3 power tests/duds. No disruptions today. Details _______ 990302xxx HUTCH PHYSICS_OPERATOR Mar 2 1999 8:41:28:793AM . . . . . . . . . . . . . . . . . . . . MP 230 Flappers! Pitcher/Hutch Cold Start. Engineering settings from 990225001. Load from 990225003. This is a 0.8 kA shot with a TF twiddle at .58-.65s. It has 30 ms Ar puff. Also a zxl ramp apparently to compensate something else. Flappers are reported ready. -------------------------------------------------------------------------------- 990302001 HUTCH PHYSICS_OPERATOR Mar 2 1999 9:06:42:123AM . . . . . . . . . . . . . . . . . . . . Apparently all the plcs needed to be rebooted. Tuesday OH test. Many CAMAC errors. But we won't bother to do it again. Tom working on fixing the errors. Load the shot into model. -------------------------------------------------------------------------------- 990302001 HUTCH PHYSICS_OPERATOR Mar 2 1999 9:31:33:280AM . . . . . . . . . . . . . . . . . . . . cmod$models disk is reported corrupted and needing to be rebuilt from backup. TWF indicates at least a one hour delay. -------------------------------------------------------------------------------- 990302002 HUTCH PHYSICS_OPERATOR Mar 2 1999 10:50:49:030AM . . . . . . . . . . . . . . . . . . . . Wolfe filling in for Ian. Before shot #2, restarted PCS with PCS/NOCOPY and loaded into model. This should put the model file Ian was working on into the live area. According to TWF, no coldstart is required. -------------------------------------------------------------------------------- 990302002 HUTCH PHYSICS_OPERATOR Mar 2 1999 11:05:22:686AM . . . . . . . . . . . . . . . . . . . . Chopper test. It worked. Camac seems to have worked as well. Set up for plasma. -------------------------------------------------------------------------------- 990302003 HUTCH PHYSICS_OPERATOR Mar 2 1999 11:11:16:483AM . . . . . . . . . . . . . . . . . . . . Dud NO EF2. Engineering operator error. -------------------------------------------------------------------------------- 990302003 HUTCH PHYSICS_OPERATOR Mar 2 1999 11:24:47:140AM . . . . . . . . . . . . . . . . . . . . Wolfe points out that EF1L is not following its demand. This is the usual problem -------------------------------------------------------------------------------- 990302004 HUTCH PHYSICS_OPERATOR Mar 2 1999 11:43:32:356AM . . . . . . . . . . . . . . . . . . . . Fizzle. EF1L is over 100A more negative than on the corresponding shot I loaded from. It seems highly likely that this problem with the power supply is the cause of this fizzle. Therefore we ask for engineering to fix this PS. Engineering goes out and probes the board but the problem has gone. They say this has happened before and that probing it like this makes it go away possibly for weeks. -------------------------------------------------------------------------------- 990302005 HUTCH PHYSICS_OPERATOR Mar 2 1999 12:05:42:200PM . . . . . . . . . . . . . . . . . . . . Plasma. The EF1L problem is not fixed but is smaller. Got only 1 MW RF, not 2. Late ELM-free H-mode. -------------------------------------------------------------------------------- 990302006 HUTCH PHYSICS_OPERATOR Mar 2 1999 12:25:50:623PM . . . . . . . . . . . . . . . . . . . . Plasma. Similar shot. CAmac failure on some of the magnetics. Zxl is riding about +1cm despite the request for a ramp from zero to -1cm. I suspect this is caused by the voltage offset in EF1L that is still present. The programmed voltage is about zero. zxl phys A out has about +8000 during the later part of the ramp. gain is 8. Mout is +100V. But actual voltage is about +30V. RF just over 1MW. The second transmitter is not working. -------------------------------------------------------------------------------- 990302007 HUTCH PHYSICS_OPERATOR Mar 2 1999 12:44:51:750PM . . . . . . . . . . . . . . . . . . . . Plasma. Still only about 1MW RF. This is what is holding us up. Put +70V in EF1L Vs in segment 2 to try to compensate for the power supply offset and hence get zxl substantially closer to what we are asking for. -------------------------------------------------------------------------------- 990302008 HUTCH PHYSICS_OPERATOR Mar 2 1999 1:20:25:700PM . . . . . . . . . . . . . . . . . . . . Fizzle. EF1l a bit more negative. Cell access for Boivin, Fiore, and RF attenuator switch. Removed the EF1L voltage tweak because engineering thinks the PS is fixed. -------------------------------------------------------------------------------- 990302009 HUTCH PHYSICS_OPERATOR Mar 2 1999 1:39:56:576PM . . . . . . . . . . . . . . . . . . . . Plasma. EF1L is not fixed. RF about 1.2 MW plus ratty behaviour. H-modes are essentially ELM-free. Load from 990302008 to get back my EF1L voltage offset correction. Open the flappers next shot. Added a second TF twiddle from .9 to 1.05s. -------------------------------------------------------------------------------- 990302010 HUTCH PHYSICS_OPERATOR Mar 2 1999 2:02:30:543PM . . . . . . . . . . . . . . . . . . . . Plasma. EF1L works correctly to spite me. Flappers opened. Install offset correction of -0.01 in zxl. It seems that not all of the offset is caused by the power supply. Flappers closed next shot. -------------------------------------------------------------------------------- 990302011 HUTCH PHYSICS_OPERATOR Mar 2 1999 2:29:02:640PM . . . . . . . . . . . . . . . . . . . . Plasma. Got 1.5MW from transmitter 2. Giving up on transmitter 1 except for tuning. Zxl offset does not seem to have done anything. That is because its units are Amp Meters. Put zxl offset to +8000. Disable argon. -------------------------------------------------------------------------------- 990302012 HUTCH PHYSICS_OPERATOR Mar 2 1999 2:47:14:686PM . . . . . . . . . . . . . . . . . . . . Plasma. 1.5MW. Still has radiation accumulation. zxl finally responds. Reduce Rcur by about 3mm to increase the outer gap. zxl offset ot 6000. It was a little high. -------------------------------------------------------------------------------- 990302013 HUTCH PHYSICS_OPERATOR Mar 2 1999 3:09:33:216PM . . . . . . . . . . . . . . . . . . . . Plasma. Radiation seems slightly better controlled but still reverts to L-mode. -------------------------------------------------------------------------------- 990302014 HUTCH PHYSICS_OPERATOR Mar 2 1999 3:18:40:623PM . . . . . . . . . . . . . . . . . . . . Plasma. Flappers open at 0.8s. H-mode somewhat stabilizes but still not a very good EDA. PG3 V to 50 volts during 40-80ms. Target density to 1.2e20 nl04. Reenable argon. -------------------------------------------------------------------------------- 990302015 HUTCH PHYSICS_OPERATOR Mar 2 1999 3:52:16:826PM . . . . . . . . . . . . . . . . . . . . Plasma. H-modes become clearly ELM-free. Probably raising the density was the wrong direction to go. Lower nl04 demand to 0.7. Disable argon. -------------------------------------------------------------------------------- 990302016 HUTCH PHYSICS_OPERATOR Mar 2 1999 4:19:13:763PM . . . . . . . . . . . . . . . . . . . . Plasma. Still not a long-pulse EDA. Back to 1.e20 nl04. Install an RF ramp for threshold studies. -------------------------------------------------------------------------------- 990302017 HUTCH PHYSICS_OPERATOR Mar 2 1999 4:42:46:060PM . . . . . . . . . . . . . . . . . . . . Plasma. H threshold about 0.9MW. Flappers closed. Cooling is very slow today. -------------------------------------------------------------------------------- 990302018 HUTCH PHYSICS_OPERATOR Mar 2 1999 4:52:50:513PM . . . . . . . . . . . . . . . . . . . . Plasma. Flappers open but CSP is not quite certain. Threshold about 0.96MW, essentially just the same as with them closed. Last shot: repeat. -------------------------------------------------------------------------------- 990302018 HUTCH PHYSICS_OPERATOR Mar 2 1999 5:02:44:560PM . . . . . . . . . . . . . . . . . . . . Plasma. Threshold 0.96MW. Flappers open? |
| Session Leader Comments | |||
| Mar 2 1999 09:04:03:357AM | Spencer Pitcher | MP 230 Effect of Divertor Baffling on Confinement, Thresholds and the ELM-free/EDA Boundary The purpose of this experiment is to investigate the effect of divertor baffling on confinement, H-mode thresholds and the ELM-free/EDA boundary. Conditions in the pedestal/edge region will be carefully monitored. We will perform two distinct types of discharges in this mini-proposal, although not necessarily in the following order. The first, essentially a shot by shot target density scan at fixed RF power, will (potentially) map out the effect on ELM-free, EDA and L-mode discharges, and in the process determine ELM-free - EDA - L-mode boundaries. (We presume that the effect of the flapper on Ohmic confinement will already be known from an earlier use of the flapper.) We will run alternate discharges, i.e. first with flaps closed for the entire discharge and then a comparison discharge with all flaps open. At a later point, if steady state conditions are obtained, e.g. in EDA or L-mode discharges, then we will open the flaps during the discharge. The second experiment, consisting of an RF (step-wise) power ramp at different target densities will investigate the effect of mid-plane pressure on H-mode threshold. Again, we will run alternate discharges, flapper closed and then flapper open. | |
| Mar 2 1999 11:55:21:577AM | 990302005 | Spencer Pitcher | flapper closed RF power only 1 MW, poor H-mode |
| Mar 2 1999 12:20:50:123PM | 990302006 | Spencer Pitcher | flapper closed RF power only 1 MW, poor H-mode |
| Mar 2 1999 01:56:55:717PM | 990302010 | Spencer Pitcher | flappers open at t = -0.2 s, close at t = 1.5 s shot 10 has roughly half the divertor neutral pressure of shot 9 |
| Mar 2 1999 02:11:11:013PM | 990302011 | Spencer Pitcher | flappers closed |
| Mar 2 1999 02:36:11:483PM | 990302012 | Spencer Pitcher | flappers closed |
| Mar 2 1999 03:01:53:763PM | 990302013 | Spencer Pitcher | flappers open t = -.2 s, closed t = 1.5 s compare shots 12,13........shot 13 div press approx factor 2 lower |
| Mar 2 1999 03:25:34:717PM | 990302014 | Spencer Pitcher | flappers open t = 0.8 s, closed t = 1.5 s divertor neutral density pumps out at t = 0.8 |
| Mar 2 1999 06:32:02:013PM | 990302015 | Spencer Pitcher | flappers open t = 0.8 s, closed t = 1.5 s problem with flapper power supply, however, flaps open as requested improve? EDA by using higher target density |
| Mar 2 1999 03:44:37:153PM | 990302016 | Spencer Pitcher | flappers closed improve? EDA by using lower target density |
| Mar 2 1999 04:18:26:200PM | 990302017 | Spencer Pitcher | flappers closed RF power ramp, 0.5 MW @ 0.5 s to 1.5 MW @ 1.2 s jumps to H-mode at 0.95 MW, nl04 = 1.0 |
| Mar 2 1999 06:02:54:607PM | 990302018 | Spencer Pitcher | flappers from t = -0.2 s to 1.5 s, problem with flapper power supply, flaps open approx 15 deg (fully open = 70 deg, fully closed = 0 deg) RF power ramp, 0.5 MW @ 0.5 s to 1.5 MW @ 1.2 s jumps to H-mode at 1.0 MW, nl04 = 1.0 |
| Mar 2 1999 06:33:26:090PM | 990302019 | Spencer Pitcher | flappers from t = -0.2 s to 1.5 s, problem with flapper power supply, flaps open approx 30 deg (fully open = 70 deg, fully closed = 0 deg) (this problem was fixed after the run by turning off power supply and relay unit and switching back on again) RF power ramp, 0.5 MW @ 0.5 s to 1.5 MW @ 1.2 s jumps to H-mode at 1.0 MW, nl04 = 1.0 |
| Physics Operator Comments | |||
| Mar 2 1999 08:41:28:793AM | Ian Hutchinson | MP 230 Flappers! Pitcher/Hutch Cold Start. Engineering settings from 990225001. Load from 990225003. This is a 0.8 kA shot with a TF twiddle at .58-.65s. It has 30 ms Ar puff. Also a zxl ramp apparently to compensate something else. Flappers are reported ready. | |
| Mar 2 1999 09:06:42:123AM | 990302001 | Ian Hutchinson | Apparently all the plcs needed to be rebooted. Tuesday OH test. Many CAMAC errors. But we won't bother to do it again. Tom working on fixing the errors. Load the shot into model. |
| Mar 2 1999 09:31:33:280AM | 990302001 | Ian Hutchinson | cmod$models disk is reported corrupted and needing to be rebuilt from backup. TWF indicates at least a one hour delay. |
| Mar 2 1999 10:50:49:030AM | 990302002 | Ian Hutchinson | Wolfe filling in for Ian. Before shot #2, restarted PCS with PCS/NOCOPY and loaded into model. This should put the model file Ian was working on into the live area. According to TWF, no coldstart is required. |
| Mar 2 1999 11:05:22:687AM | 990302002 | Ian Hutchinson | Chopper test. It worked. Camac seems to have worked as well. Set up for plasma. |
| Mar 2 1999 11:11:16:483AM | 990302003 | Ian Hutchinson | Dud NO EF2. Engineering operator error. |
| Mar 2 1999 11:24:47:140AM | 990302003 | Ian Hutchinson | Wolfe points out that EF1L is not following its demand. This is the usual problem |
| Mar 2 1999 11:43:32:357AM | 990302004 | Ian Hutchinson | Fizzle. EF1L is over 100A more negative than on the corresponding shot I loaded from. It seems highly likely that this problem with the power supply is the cause of this fizzle. Therefore we ask for engineering to fix this PS. Engineering goes out and probes the board but the problem has gone. They say this has happened before and that probing it like this makes it go away possibly for weeks. |
| Mar 2 1999 12:05:42:200PM | 990302005 | Ian Hutchinson | Plasma. The EF1L problem is not fixed but is smaller. Got only 1 MW RF, not 2. Late ELM-free H-mode. |
| Mar 2 1999 12:25:50:623PM | 990302006 | Ian Hutchinson | Plasma. Similar shot. CAmac failure on some of the magnetics. Zxl is riding about +1cm despite the request for a ramp from zero to -1cm. I suspect this is caused by the voltage offset in EF1L that is still present. The programmed voltage is about zero. zxl phys A out has about +8000 during the later part of the ramp. gain is 8. Mout is +100V. But actual voltage is about +30V. RF just over 1MW. The second transmitter is not working. |
| Mar 2 1999 12:44:51:750PM | 990302007 | Ian Hutchinson | Plasma. Still only about 1MW RF. This is what is holding us up. Put +70V in EF1L Vs in segment 2 to try to compensate for the power supply offset and hence get zxl substantially closer to what we are asking for. |
| Mar 2 1999 01:20:25:700PM | 990302008 | Ian Hutchinson | Fizzle. EF1l a bit more negative. Cell access for Boivin, Fiore, and RF attenuator switch. Removed the EF1L voltage tweak because engineering thinks the PS is fixed. |
| Mar 2 1999 01:39:56:577PM | 990302009 | Ian Hutchinson | Plasma. EF1L is not fixed. RF about 1.2 MW plus ratty behaviour. H-modes are essentially ELM-free. Load from 990302008 to get back my EF1L voltage offset correction. Open the flappers next shot. Added a second TF twiddle from .9 to 1.05s. |
| Mar 2 1999 02:02:30:543PM | 990302010 | Ian Hutchinson | Plasma. EF1L works correctly to spite me. Flappers opened. Install offset correction of -0.01 in zxl. It seems that not all of the offset is caused by the power supply. Flappers closed next shot. |
| Mar 2 1999 02:29:02:640PM | 990302011 | Ian Hutchinson | Plasma. Got 1.5MW from transmitter 2. Giving up on transmitter 1 except for tuning. Zxl offset does not seem to have done anything. That is because its units are Amp Meters. Put zxl offset to +8000. Disable argon. |
| Mar 2 1999 02:47:14:687PM | 990302012 | Ian Hutchinson | Plasma. 1.5MW. Still has radiation accumulation. zxl finally responds. Reduce Rcur by about 3mm to increase the outer gap. zxl offset ot 6000. It was a little high. |
| Mar 2 1999 03:09:33:217PM | 990302013 | Ian Hutchinson | Plasma. Radiation seems slightly better controlled but still reverts to L-mode. |
| Mar 2 1999 03:18:40:623PM | 990302014 | Ian Hutchinson | Plasma. Flappers open at 0.8s. H-mode somewhat stabilizes but still not a very good EDA. PG3 V to 50 volts during 40-80ms. Target density to 1.2e20 nl04. Reenable argon. |
| Mar 2 1999 03:52:16:827PM | 990302015 | Ian Hutchinson | Plasma. H-modes become clearly ELM-free. Probably raising the density was the wrong direction to go. Lower nl04 demand to 0.7. Disable argon. |
| Mar 2 1999 04:19:13:763PM | 990302016 | Ian Hutchinson | Plasma. Still not a long-pulse EDA. Back to 1.e20 nl04. Install an RF ramp for threshold studies. |
| Mar 2 1999 04:42:46:060PM | 990302017 | Ian Hutchinson | Plasma. H threshold about 0.9MW. Flappers closed. Cooling is very slow today. |
| Mar 2 1999 04:52:50:513PM | 990302018 | Ian Hutchinson | Plasma. Flappers open but CSP is not quite certain. Threshold about 0.96MW, essentially just the same as with them closed. Last shot: repeat. |
| Mar 2 1999 05:02:44:560PM | 990302018 | Ian Hutchinson | Plasma. Threshold 0.96MW. Flappers open? |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 08:58:21:200AM | Test | Bad | oh supplies appear to be all right on the reat time scope/ CAMAC fail |
| 2 | 11:00:58:967AM | Test | Ok | efc chopper test |
| 3 | 11:08:32:357AM | Plasma | Bad | ef2 u,l plc current limit set to 0 |
| 4 | 11:22:16:030AM | Plasma | Ok | no faults/fizzel |
| 5 | 11:42:37:450AM | Plasma | Ok | No Faults / Plasma |
| 6 | 12:00:36:340PM | Plasma | Ok | no faults/plasma |
| 7 | 12:23:26:060PM | Plasma | Ok | No Faults / Plasma |
| 8 | 12:43:53:810PM | Plasma | Ok | No Faults |
| 9 | 01:23:04:170PM | Plasma | Ok | no faults plasma |
| 10 | 01:40:56:437PM | Plasma | Ok | No Faults / Plasma |
| 11 | 02:02:30:467PM | Plasma | Ok | no faults/plasma |
| 12 | 02:25:06:077PM | Plasma | Ok | no faults/plasma |
| 13 | 02:45:47:543PM | Plasma | Ok | No Faults / Plasma |
| 14 | 03:08:33:357PM | Plasma | Ok | No Faults / Plasma |
| 15 | 03:30:40:043PM | Plasma | Ok | no faults/plasma |
| 16 | 03:49:37:483PM | Plasma | Ok | No Faults / Plasma |
| 17 | 04:12:20:140PM | Plasma | Ok | No Faults / Plasma |
| 18 | 04:34:49:077PM | Plasma | Ok | No Faults / Plasma |
| 19 | 04:54:08:577PM | Plasma | Ok | No Faults / Plasma |