| Miniproposals | ||||||||||
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| Operators | |
| Session leader(s): | Jim Terry |
| Physics operator(s): | Joseph Snipes |
| Engineering operator(s): | Unknown |
| Engineering Operator Run Comment |
| MP 015; Edge Density Scan |
| Session Leader Plans |
| Physics Operators Plans |
| Session Leader Summaries |
| Physics Operator Summaries |
| Entered: Jul 7 2004 04:36:50:300PM |
| Author: To Be Determined |
From: LEADER::SNIPES Date: 12-AUG-1993 16:36:20 Description: Physics operator run summary 930812 The run was supposed to start at 8:00 am and finish at 4:00 pm for the BBQ. Due to problems with the TORVAC PLC, we were delayed about an hour in the morning. In the end, we managed 23 shots, all with more than 100 kA of plasma, a few disruptions, but mostly good discharges. Most of the time was spent trying to keep constant plasma current and density with success toward the end of the run keeping the current constant at about 400 ka from 100 to 400 ms and the density reasonably constant at 4 x 10**19 /m**2 line average from 200 to 400 ms. Attempts to vary the density were rather unsuccessful in that the density varied from about 3.9 to 4.7 x 10**19 /m**2. Increasing the gas led to disruptions, while decreasing the gas did not reduce the density substantially due to gas evolving from the walls or limiter. After some limiter conditioning with plasmas, we ran successfully with the RF limiter at 93 cm. The second to last shot of the day was perhaps the best 930812021 having the flattest current and density, though 22 and 23 were also quite good. Gas puffing with short 6 ms puffs every 11 ms or so led to very nice constant densities, though the H alpha tends to see each puff. These plasmas will also be good for gas fueling studies. One other thing learned about the operation today was the very sensitive nature of the initial gas puff. If there is too much gas, the line density rises to 4 z 10**19/m**2 by 100 ms and the plasma becomes very disruptive. Puffing somewhat less gas such that the density rose to 3 x 10**19/m**2 by 100 ms led to much more stable plasmas. However, reducing the gas puff any further led to high signals on the hard x ray monitor. So, it appears that the way to run is with an optimum first gas puff on B side upper (Pulse Gas 2), then use A side (Pulse Gas 3) with varying puffs to raise or lower the density. However, the "optimum" first gas puff may change during the day due to changes in wall conditioning. Nonetheless, the changes in the optimum are small. Overall it was quite a good run with some useful physics data and with good control of the plasma position, current, and density. |
| Session Leader Comments | |||
| Aug 12 1993 08:54:10:610AM | Jim Terry | Run delayed due to PLC problems with TORVAC. The slave PLC in the cell needed to be
switched off and on again to allow the system to communicate with the control room. So, cooling had to be switched off and the cell had to be opened and ventilated to allow someone to enter to switch the bloody thing off and on. | |
| Aug 12 1993 04:18:39:420PM | Jim Terry | In this run we will attempt to execute Mini-proposal No. 015. The purpose of the run is
to measure changes in the edge parameters, n_e, T_e, the scrape-off length, the impurity content, Z_eff, and the radiated power as a function of main plasma density. Thus, we will attempt to scan the plasma density while keeping the input power constant. | |
| Aug 12 1993 09:04:42:050AM | 930812001 | Jim Terry | This run will attempt to execute Mini-proposal No. 015. The purpose of the run is
to measure changes in the edge parameters, n_e, T_e, the scrape-off length, the impurity content, Z_eff, and the radiated power as a function of main plasma density. Thus, we will attempt to sscan the plasma density while keeping the input power constant. |
| Aug 12 1993 09:15:35:930AM | 930812001 | Jim Terry | This shot used the loaded settings from shot 930811017. The RF limiter has been
moved in from yesterday's position to R=90.0 cm. The pre-fill pressure was 1.2e-5 torr. The shot disrupted at about 200 ms at a current of about 200 kA. The current was not smooth from about 100 ms 'til the disruption. The magnetics show that the plasma was diverted from 150ms to 190 ms. |
| Aug 12 1993 09:26:29:890AM | 930812001 | Jim Terry | We also note from the magnetics that the plasma was touching the RF limiter from
about 60 ms until it diverted at about 150 ms. |
| Aug 12 1993 09:23:55:120AM | 930812002 | Jim Terry | Moved the RF limiter was moved back out for this shot to R=95.0 cm. Prefill was
programmed for 1.2e-5 torr again, but the torus pressure drifted enough before PULSE that TORVAC did not allow the shot to go through. Thus, shot classified as 'bad'. |
| Aug 12 1993 09:39:43:270AM | 930812003 | Jim Terry | Plasma disrupted at 260 ms with a current of 0.40 MA. Things were not so good even
at about 90 ms. |
| Aug 12 1993 09:53:07:800AM | 930812004 | Jim Terry | Backed off the pulsed gas early in the shot. Programming voltages on both
valve 2 and 3 were reduced. Good shot - peak current is 0.55 MA, discharge length is 750 ms. CII shows that the plasma diverted from about 190 to about 460 ms. The magnetics show the same. Plasma TV shows a good upper X pt. |
| Aug 12 1993 10:27:08:590AM | 930812005 | Jim Terry | Good shot, peak current was 0.55 MA, plasma lasts about 750 ms. CII shows that
the plasma is diverted from about 190 until about 450 ms. |
| Aug 12 1993 10:30:45:770AM | 930812005 | Jim Terry | Good shot, peak current was 0.55 MA, plasma lasts about 750 ms. CII shows that
the plasma is diverted from about 190 until about 450 ms. Strike pt seen on inner divertor. |
| Aug 12 1993 10:51:21:630AM | 930812006 | Jim Terry | Good shot, very similar to the 005, peak current was 0.55 MA, plasma lasts
about 750 ms. CII again shows that the plasma is diverted from about 190 until about 450 ms. |
| Aug 12 1993 11:03:43:800AM | 930812007 | Jim Terry | Good shot, similar to 004, 005 006, peak current was 0.55 MA, plasma lasts
about 750 ms. |
| Aug 12 1993 11:05:55:350AM | 930812007 | Jim Terry | Highest temperature measured on the RF limiter was 79 degrees C. (Limiter at
R=95.0 cm) |
| Aug 12 1993 11:48:04:970AM | 930812008 | Jim Terry | For this shot , moved the RF limiter from R=95.0 cm in to R=93.0 cm.
Highest temperature measured on the RF limiter was about 85 degrees C. Plasma disrupted at about 250 ms. Limiter was being struck by slide-aways (glowing on TV). |
| Aug 12 1993 12:07:14:680PM | 930812009 | Jim Terry | For this shot , moved the RF limiter back from R=93.0 cm in to R=95.0 cm.
Good shot, plasma current max. was 0.46 MA. |
| Aug 12 1993 12:09:15:580PM | 930812010 | Jim Terry | For this shot, the RF limiter was moved into R=90.0 (from R=95.0 cm).
Plasma disrupted at 250 ms. |
| Aug 12 1993 12:26:38:390PM | 930812011 | Jim Terry | For this shot, the RF limiter was moved back out from R=90.0 to R=95.0 cm.
Good shot, current max at 0.44 MA and flatter. Very low hard x-rays. Diverted after about 300 ms 'til about 500 ms (from CII sig.). |
| Aug 12 1993 12:39:35:740PM | 930812012 | Jim Terry | For this shot, the RF limiter was moved back from R=95.0 to R=93.0 cm.
Shot disrupted at 390 ms; current max was 0.30 MA. Diverted after about 230 ms 'til the disruption (from CII sig.). |
| Aug 12 1993 01:02:11:650PM | 930812013 | Jim Terry | For this shot, the RF limiter was still at R=93.0 cm.
Good shot, current max was 0.42 MA and pretty well flat-topped. Diverted after about 350 ms 'til 500 ms (from CII sig.). |
| Aug 12 1993 01:35:14:610PM | 930812014 | Jim Terry | For this shot, the RF limiter was still at R=93.0 cm.
Good shot, current max was 0.42 MA and pretty well flat-topped. Strange increase in N_e, P_rad, etc at about 350 ms. Not obviously diverted on CII sig. Some magnetic reconstructions show diversion. |
| Aug 12 1993 01:48:56:180PM | 930812015 | Jim Terry | For this shot, the RF limiter was still at R=93.0 cm.
Shot began disrupting at 200 ms, finally died at 300 ms. |
| Aug 12 1993 02:04:44:390PM | 930812016 | Jim Terry | For this shot, the RF limiter was still at R=93.0 cm.
Shot disrupted at 270 ms. |
| Aug 12 1993 02:44:10:450PM | 930812018 | Jim Terry | Good shot. Current max was 0.41 MA.
Limiter still at 93.0 cm |
| Aug 12 1993 03:00:32:620PM | 930812019 | Jim Terry | Good shot. Current max was 0.41 MA.
Central line density was flat-topped at 4.75e19 from 160 ms to 300 ms. Limiter still at 93.0 cm |
| Aug 12 1993 03:14:45:940PM | 930812020 | Jim Terry | Disruptive shot. Current max was 0.33 MA.
Finally died at 286 ms. Limiter still at 93.0 cm |
| Aug 12 1993 03:32:08:500PM | 930812021 | Jim Terry | Good shot. Current max was 0.43 MA and flat. Central line density was 4.3e19 and flat.
Discharge length 750 ms. Limiter still at 93.0 cm |
| Aug 12 1993 03:34:42:280PM | 930812021 | Jim Terry | Best shot of the day - so far.
|
| Aug 12 1993 03:49:27:130PM | 930812022 | Jim Terry | Good shot - curent max. is 0.42 MA; central line density is unchanged from the
last shot at 4.3e19. Hard x-rays present early in the shot. |
| Aug 12 1993 04:13:06:320PM | 930812023 | Jim Terry | Good shot - curent max. is 0.42 MA; central line density is 3.9e19 and flat-topped.
|
| Physics Operator Comments | |||
| Aug 12 1993 10:11:37:280AM | 930812005 | Jim Terry | For this shot, we reduced the programming current on EF1 upper and lower
over the time interval t=150 ms to 425 ms from 3300 A to 2700 A. Chopper on from 650 to 700 ms. |
| Aug 12 1993 10:34:25:540AM | 930812006 | Jim Terry | For this changed OH programming voltages as follows:
OH1 at 120 ms from -400 to -350 OH2L at 120 ms from -45 to -35 OH2U at 120 ms from -60 to -50. |
| Aug 12 1993 10:57:47:170AM | 930812007 | Jim Terry | For this shot, changed OH programming voltages as follows:
OH1 added pt at 150 ms at -200 OH2L added pt at 150 ms at -20 OH2U added pt at 150 ms at -20 Turned the feedback on KAPPA off. Increased the pulsed gas programming voltage on both 2 and 3 (2nd puff). |
| Aug 12 1993 11:20:33:770AM | 930812008 | Jim Terry | For this shot, changed the M matrix coef. for OH1 from 1e-2 to 5e-3.
Increased the prefill pressure from 1.2e-5 to 1.3e-5 torr. |
| Aug 12 1993 11:44:45:500AM | 930812009 | Jim Terry | For this shot, extended the R and Z_CURR feedback from 0.6 s to 1.0 s.
We changed the OH1 programming voltage at 80 ms to -100 V and after 150 ms changed it from -200 to -150 V. Increased the pulsed gas 2 programming voltage. Increased prefill pressure from 1.3e-5 to 1.4e-5 torr. |
| Aug 12 1993 12:03:08:020PM | 930812010 | Jim Terry | For this shot, changed the Z_CURR derivative gain from 1 to 0.5 and increased the
prop. gain from 7. to 8. We changed the OH1 programming voltage from 80 ms to 120 ms from -100 V to 0. Decreased prefill pressure from 1.4e-5 to 1.2e-5 torr. |
| Aug 12 1993 12:19:37:990PM | 930812011 | Jim Terry | For this shot, decreased the gas puffs from valve 3 at 250 and 300 ms.
Turned the Ar gas puff on for the 1st time today. RF limiter back to 95.0 cm Good shot. |
| Aug 12 1993 12:37:32:070PM | 930812012 | Jim Terry | For this shot, removed the gas puffs from valve 3 at 200 and 250 ms.
Changed OH1 programming voltage so that it is now 0 V from 70 ms to 150 ms. RF limiter in to 93.0 cm Disrupted at 390 ms. |
| Aug 12 1993 12:50:55:720PM | 930812013 | Jim Terry | For this shot, raise the prefill from 1.2e-5 to 1.3e-5 torr.
RF limiter still at 93.0 cm. Good shot. |
| Aug 12 1993 01:32:23:780PM | 930812014 | Jim Terry | For this shot, reduced the prefill from 1.3e-5 to 1.2e-5 torr.
RF limiter still at 93.0 cm. Move the gas puff at 150 ms back to 140 ms and add 8 more gas puffs every 11 ms from 170 ms to 300 ms. Antenna moved into 95.0 cm Good shot. |
| Aug 12 1993 01:45:52:940PM | 930812015 | Jim Terry | For this shot, added gas puffs every 11 ms from 300 ms to 400 ms.
Increased gas puff from valve 2, early. RF limiter still at 93.0 cm. Antenna still at 95.0 cm. Disrupted starting at 200 ms dying finally at 300 ms. |
| Aug 12 1993 02:03:30:240PM | 930812016 | Jim Terry | For this shot, decreased the gas puff at 120 ms from gas valve 3.
RF limiter still at 93.0 cm. Antenna still at 95.0 cm. Raised the gain on EF3 in R_CURR after 350 ms from 4e-2 to 5.17e-2. Disrupted at 270 ms. |
| Aug 12 1993 02:35:05:380PM | 930812018 | Jim Terry | For this shot, decreased the gas puff from gas valve 2.
Programmed EF4 voltage to go negative (to a negative limit of -400) between 200 and 250 ms. Good shot. Quite similar to Shot 940812014. |
| Aug 12 1993 02:57:24:250PM | 930812019 | Jim Terry | For this shot, maintained the OH1 programming at -150 V out to 400 ms (previously it
was raised to zero from -150 V after 350 ms). Added 11ms puffs on pulsed valve 3 out to 400 ms. Good shot. |
| Aug 12 1993 03:12:50:980PM | 930812020 | Jim Terry | For this shot, loaded the programming for pulsed gas valve 2 from shot
930812014. EF4 programming voltage at -1000 from 0 to 250 ms. Shot disruptive, finally died at 286 ms. |
| Aug 12 1993 03:30:36:850PM | 930812021 | Jim Terry | For this shot, reduced pulsed gas programming on valve 2.
Also reduced the valve 3 gas puffs at 75 and 130 ms. Good shot. |
| Aug 12 1993 03:45:25:620PM | 930812022 | Jim Terry | For this shot, removed the valve 3 gas puff at 130 ms.
Good shot. |
| Aug 12 1993 04:10:21:670PM | 930812023 | Jim Terry | For this shot, removed the valve 3 gas puff at 75 ms.
Increased gas puff from valve 2. Shot delayed by someone typing Good shot. |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 08:57:56:730AM | Plasma | Ok | 1 hour late. Disruptive plasma. Typed for 10 minutes in logbook; it bl |
| 2 | 09:16:42:790AM | Plasma | Bad | TORVAC drifted off setpoint while in pulse state and blocked pulse; THIS |
| 3 | 09:25:18:730AM | Plasma | Ok | 400 kA disruption |
| 4 | 09:42:17:930AM | Plasma | Ok | 500 kA shot; EFC chopper tests OK; hooked up to EFC magnets next shot |
| 5 | 10:05:54:290AM | Plasma | Ok | Good shot No faults, |
| 6 | 10:30:02:060AM | Plasma | Ok | Plasma shot no faults. |
| 7 | 10:55:12:050AM | Plasma | Ok | Plasma shot No faults. |
| 8 | 11:18:35:910AM | Plasma | Ok | Plasma shot No faults. |
| 9 | 11:42:47:020AM | Plasma | Ok | shot |
| 10 | 11:58:57:910AM | Plasma | Ok | shot coming |
| 11 | 12:13:04:730PM | Plasma | Ok | argon puff |
| 12 | 12:30:40:390PM | Plasma | Ok | slow torvac permissive. into check twice |
| 13 | 12:45:31:130PM | Plasma | Ok | CRYO PC/paragon died on going into init |
| 14 | 01:14:00:260PM | Plasma | Ok | 400 kA; CRYO PC problem involved schedule blocks inserted into strategy |
| 15 | 01:39:07:780PM | Plasma | Ok | 400 kA; changed gain in EF4 lockout regulator for next shot |
| 16 | 01:56:39:600PM | Plasma | Ok | Ratty plasma |
| 17 | 02:12:11:650PM | Plasma | Ok | OK |
| 18 | 02:26:37:350PM | Plasma | Ok | long 400 kA shot |
| 19 | 02:45:11:740PM | Plasma | Ok | First successful double-swing of EF4 supply with no single-phase |
| 20 | 03:04:04:850PM | Plasma | Ok | Plasma Disrupted as EF4 current went negative; double-swinging EF4 - Thr |
| 21 | 03:20:21:300PM | Plasma | Ok | Longer shot; EF4 lockout delay about 37 msec |
| 22 | 03:35:58:340PM | Plasma | Ok | Over 450 msec at 400 kA +/- 10% |
| 23 | 03:59:40:110PM | Plasma | Ok | Shot was held for 9 minutes in Z-meter analysis; this cost a shot. The |