Alcator C-Mod Run 1051031 Information

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Miniproposals

Operators
Session leader(s):
Physics operator(s):Robert Granetz
Engineering operator(s):Bill Cochran

Engineering Operator Run Comment
Power System Tests

Session Leader Plans

Physics Operators Plans
Entered: Oct 31 2005 08:53:38:480AM
Author: Robert Granetz
Most of the day, if not all of it, will be occupied with power systems test.
If these are successful and go quickly enough, we will try for plasma towards the
end of the day. I suggest starting with 1050825027, which is a standard 1 MA, 5.4 T
fiducial shot (most recent gas jet shot).
Entered: Oct 31 2005 09:59:12:450AM
Author: Robert Granetz
Engineering setup for Monday 31 Oct 2005

Plasma startup

Session leader: none
Physics operator: R. Granetz

Overnight ECDC in D2, and bake at 60 C.

Run begins whenever the power supply testing is completed successfully.
This will not be until late in the day, if at all.

Power systems as on 1050825027 (1.0 MA fiducial, 5.4 T, lower single null)

A-coil configuration: normal [+Dtop -Dbot -Jtop +Jbot] and enabled.

Gas Setup:
   fill B-Top            with  6 psi D2  Hybrid enabled  (PG4)
   fill B-side lower     with  1 psi Ar + 2 psi Ne  Hybrid DISABLED (PG1)
  leave B-side upper     as is           Hybrid DISABLED (PG2)
   fill B-main (C-side)  with 40 psi D2  Hybrid enabled  (PG3)
  leave NINJA            as is           Leave DISABLED

Enable the following gate valves and shutters, assuming no vacuum problems:
  ECE, VUV, Z-bolo shutters

Torvac setup: Gate valves open

No between-shot boronization.

Important Diagnostics: magnetics, standard impurity spectroscopy

-------------------------------------------------------------------------------
ICRF Setup: No RF required today, although it can be used at will.

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Run plan: Get plasma after 2 months of manned access, during which the
          J-antenna Faraday screen was removed and the D-antenna was
          cleaned of titanium dust.

Session Leader Summaries

Physics Operator Summaries
Entered: Oct 31 2005 05:13:15:330PM
Author: Robert Granetz
Most of the day was spent doing power supply tests, which went very smoothly.

Shot 27 was our first plasma attempt, which actually worked. Shot 33 also
had a plasma that lasted until 0.36 s and got up to 0.75 MA. The carbon signal
at breakdown was quite high. All other shots after 27 were either fizzles or
no-power test shots.

The no-power test shots late in the day were an attempt to find the source of
a low-frequency rumble that we hear in the control when the alternator excitation
is on. This issue has not been resolved as of the end of the run.

Session Leader Comments

Physics Operator Comments
Oct 31 2005 10:16:16:213AM1051031007Robert GranetzTest of A-coil. I loaded A-coil pre-programmed voltage trace from segment 1 of 1050204005.
Only segment 1 is turned on, so there is no feedback (which is in segment 2, wire 9)
Oct 31 2005 10:27:59:137AM1051031007Robert GranetzThis A-coil test shot was successful. After the shot, I re-loaded shot 1050825027 (1 MA
fiducial), all segments, into DPCS.
Oct 31 2005 11:02:51:183AM1051031011Robert GranetzEF4 double swing test. I loaded the IC_EF4U wire in segment 1 with the corresponding
one from 1050204004 and turned on only segment 1.
Oct 31 2005 11:06:01:963AM1051031011Robert GranetzEF4 double swing test was successful. After the shot I reloaded 1050825027 into DPCS.
Oct 31 2005 02:46:46:550PM1051031025Robert GranetzThis is the last power test shot (TF at 150 kA). After this we will start
with plasma attempts.
Oct 31 2005 01:34:12:010PM1051031026Robert GranetzLoad shot 1050825027 (1 MA fiducial, 5.4 T, 1.0e20 m-2, SNL).

Note that the HIREX gas is only argon, as there is no neon available to mix.
Oct 31 2005 03:32:35:173PM1051031027Robert GranetzPlasma...on first attempt. Short; disrupted at t=0.15 s.

Next shot: no changes.
Oct 31 2005 03:40:57:673PM1051031028Robert GranetzFizzle. H-alpha signal is very noisy.

Next shot: reduce pre-fill by 3 ms.
Oct 31 2005 03:49:31:030PM1051031029Robert GranetzFizzle. Plenty of carbon signal.

Next shot: reduce prefill pulse by another 3 ms.
Oct 31 2005 04:06:33:110PM1051031030Robert GranetzFizzle. We have been noticing a low-frequency noise that turn on during check state and turns
off after pulse state. It has been determined that it's due to the air compressor, which
apparently has to work very hard during the shot for some reason. We suspect that an air hose
is lose somewhere.

Next shot: no power test shot to see if we can find where the compressed air leak is in
the cell. Several of us will be in the cell for the test shot.

Next shot after the test shot: reduce prefill another 3 ms (to 18 ms).
Oct 31 2005 04:42:26:983PM1051031031Robert GranetzUnable to find anything wrong with the compressed air systems. In fact, the
compressor didn't make any unusual noises. (We were in the cell with the big
door closed, and didn't hear anything unusual in there.)
Oct 31 2005 04:47:47:580PM1051031033Robert GranetzPlasma. Disrupted at t=0.36 s. Current made it to 0.75 MA.

Next shot: reduce nl_04 demand to 0.6e20 m-2 and reduce Ip demand
to 0.8 MA. The pre-programmed gas was already zero
throughout segment 2.
Oct 31 2005 04:55:17:030PM1051031034Robert GranetzFizzle.

Next shot: no changes. This will be the last one for today.
Oct 31 2005 05:09:10:830PM1051031035Robert GranetzFizzle.

End of run.

Engineering Operator Comments
ShotTimeTypeStatusComment
108:57:00:090AMTestOkShot Cycle Test
209:11:42:167AMTestOkEF2U PLC Test
309:20:49:340AMTestOkEF2L PLC Test
409:30:01:667AMTestOkEFC Chopper Test
509:40:12:137AMTestOkEFC Chopper Test
609:52:50:963AMTestOkEFC Chopper Test
710:16:35:060AMTestOkC_Coil Test
810:33:51:357AMTestOkEF3 PLC Test
910:42:52:260AMTestOkEF4 Forward Bridge PLC Test
1010:53:46:323AMTestOkEF4 Reverse Bridge PLC Test
1111:02:27:963AMTestOkEF4 Double Swing Test
1211:14:42:417AMTestOkEF1U Forward PLC Test
1311:24:35:200AMTestOkEF1U Reverse Bridge PLC Test
1511:43:17:543AMTestOkEF1L Reverse Bridge PLC Test
1611:52:42:073AMTestOkEF1 Commutation Test
1712:00:39:900PMTestOkOH1 Forward Bridge Test
1812:13:06:700PMTestOkOH1 Reverse Bridge PLC Test
1912:19:14:510PMTestOkOH2U Forward Bridge PLC Test
2012:26:45:400PMTestOkOH2U Reverse Bridge PLC Test
2112:37:14:997PMTestOkOH2L Forward Bridge PLC Test
2212:44:01:150PMTestOkOH2L Reverse Bridge PLC Test
2312:51:01:213PMTestOkOH Commutation Test
2401:08:09:450PMTestOkTF 50kA PLC test
2501:20:27:200PMTestOkTF 100kA PLC Test
2601:33:10:637PMTestOkTF 150kA PLC Test
2703:21:19:733PMPlasmaOk
2803:34:11:080PMPlasmaOk
2903:46:41:267PMPlasmaOk
3003:59:10:157PMPlasmaOk
3104:14:23:953PMTestOkNo Power Test Shot
3204:27:31:047PMTestOkNo Power Test Shot
3304:39:03:970PMPlasmaOk
3404:51:26:453PMPlasmaOk
3505:05:25:657PMPlasmaOk