Alcator C-Mod Run 1031114 Information

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Miniproposals
Miniproposal:335
Date Filed: 5/2/2003
Title:Edge plasma flows in upper verus lower x-point discharges
First Author:Brian Labombard
Session Leader:Brian Labombard (shots 1-28)

Operators
Session leader(s):Brian Labombard
Physics operator(s):Ron Parker
Engineering operator(s): Unknown

Engineering Operator Run Comment
MP #335-Edge plasma flows in upper vs lower x-point discharges PO:Parker

Session Leader Plans

Physics Operators Plans

Session Leader Summaries
Entered: Jul 7 2004 03:49:34:867PM
Author: Brian Labombard
Run Summary for 103114, MP#335: "Edge plasma flows in upper versus lower x-point discharges"

Physics Operator: R. Parker
Session Leader: B. LaBombard
________________________________________________________________________________
1031114 Run Plan

Purpose:
The primary purpose of these experiments is to investigate
the sensitivity of the magnitude and direction of the parallel plasma
flows (routinely observed in the edge plasma) to the magnetic
geometry, in particular upper, lower and double-null configurations.

This MP has been attempted 2 times before: 1030619 - only got 5
data-quality discharges (see run_summary_1030619), 1030630b (1/2 day) - got
11 good shots but the FSP probe was dead - no flow information there
(see run_summary_1030630b). The goal today is to execute the shot plan
called out in the MP with all diagnostics working.

Shot Plan:

Shot#1-3 (SNL)
Reload shot#1030630031, importing recent segment 1. Turn segment 2 on (lower
single null).
Program NL04 = 0.8x10^20 m^-2
Increase right gap by 6 mm. Decrease left gap by 1 mm.
Check probe targeting and strike-point locations.

Shot#4-6 (SNU)
Turn off segment 2, turn on segment 3 (upper single null)
Program NL04 = 0.8x10^20 m^-2
Increase right gap by 5 mm. Decrease left gap by 4 mm.
Check probe targeting.

Begin density scan with four shots at each density, 2 in SNU and 2 in SNL.

Shot#7,8 - NL04 = 0.6, SNU

Switch to SNL
9,10 - NL04 = 0.6, SNL
11,12 - NL04 = 1.0, SNL

Switch to SNU
13,14 - NL04 = 1.0, SNU
15,16 - NL04 = 1.2, SNU

Switch to SNL
17,18 - NL04 = 1.2, SNL

Begin density scan in DN configuration.

Shot#19,20 (DN)
Turn on segment 4
Program NL04 = 0.8x10^20 m^-2
Can proportional gain on SSEP be decreased to remove x-pt oscillations?
Increase right gap by 3 mm. Decrease left gap by 3 mm.
Check probe targeting.

21,22 - NL04 = 0.6, DN
23,24 - NL04 = 1.0, DN
25,26 - NL04 = 1.2, DN
________________________________________________________________________________
Result:
A variety of bugs bit us today. But, we got a solid 1/2 day's worth
of data out of a full day's run. All three probes (ASP, FSP, ISP) worked
reasonably well. However, the ISP seems to be developing an intermittent short
between the central electrode and vacuum vessel ground. Its life may be
limited so we need to use it carefully in the future. Strong flows were recorded
on the ISP again today, favoring the usual flow picture - strong flows
from the low to high-field SOL along field lines connecting these regions.
An important new element today was the use of the FSP probe
(its external wiring problem was fixed during the break).
Flows were recorded by the FSP but they appeared to be weaker than expected
We also were extra careful to get all three probes as far in as possible
(nominally at the separatrix), particularly in upper null discharges where
that data was lacking. This required us to be patient, not rushing to
get to the double null discharges. We will need another 1/2 day to complete
the MP.
John Rice reported core rotation to switch from 10 km/s to 45 km/s
counter-current in changing from lower null to upper null at NL04 = 0.6.
The chromex spectrometer succesfully recorded He+1 lines from the toroidal
fiber views.


Shot Summary
[values in () are probe rest positions for future reference]

1 - no power shot
.... long delay to fix computer problems
2 - SNL, NL04 = 0.8, probes too far out.
3 - fizzle
4 - SNL, NL04 = 0.8 - ISP current drop out near sep
5 - dud
6 - SNL, NL04 = 0.8 - ISP current drop out near sep
7 - SNL, NL04 = 0.8 - ASP(+7),FSP(-7), ISP - best data
8 - SNU, NL04 = 0.8 - ASP(+2), FSP(0), ISP
9 - SNU, NL04 = 0.8 - ASP(+6), FSP(+3), ISP
10 - SNU, NL04 = 0.8 - ASP(+7), FSP(+6), ISP - best data
11 - SNU, NL04 = 0.6 - ASP(+7.5), FSP(+7), ISP - good data
12 - SNU, NL04 = 0.6 - ASP(+7.5), FSP(+7), ISP - good data
13 - SNL, NL04 = 0.6 - ASP(+8.5),FSP(-5), ISP - outer gap too large!(?)
14 - fizzle
15 - SNL, NL04 = 0.8 - ASP(+8.5),FSP(-4), ISP - good data, wrong NL04 program!
data system problems - no magnetics data
16 - no power shot
17 - fizzle
18 - SNL, NL04 = 0.6 - ASP(+8.5),FSP(-4), ISP - good data
19 - SNL, NL04 = 1.0 - ASP(+7.5),FSP(-5), ISP - good data
20 - SNU, NL04 = 1.0 - ASP(+7.5), FSP(+7), ISP - ok data, probes could be deeper
21 - fizzle
22 - fizzle
23 - SNU, NL04 = 1.0 - ASP(+8.5), FSP(+8.5), ISP - good data
24 - fizzle
25 - fizzle
26 - fizzle
27 - SNU, NL04 = 1.0 - ASP(+8.5), FSP(+8.5), ISP - good data - oops, wrong NL04 program
28 - fizzle


Physics Operator Summaries
Entered: Jul 7 2004 04:37:19:723PM
Author: Ron Parker
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Engineering Setup and Run Plan for 11/14/03

Purpose: MP #335-Edge plasma flows in upper vs lower x-point discharges

Session Leader: LaBombard

Physics operator: Parker

ECDC overnight in D2 at 2e-4 Torr, stopping by 07:00.
Bake at 60 C overnight as well.

Run begins at 09:00 and ends at 17:00.

Power systems the same as on 1031106001

A-coils should be hooked up as on 1030507012 (+Dtop -Dbot -Jtop +Jbot), but
the power supply should NOT be enabled.


Gas setup:
fill B-Top with 6 psi D2 Hybrid enabled (PG4)
fill B-side lower with 1 psi Ar Hybrid enabled (PG1)
leave B-side upper as is Hybrid DISABLED (PG2)
fill C-side with 30 psi D2 Hybrid enabled (PG3)

Enable the following gate valves, assuming no vacuum problems:
ECE, VUV, DNB

-------------------------------------------------------------------------------
RF Setup:Transmitters 1,3 & 4 in Run On by 08:00.

Run Plan:
Start with a reload from shot# 1030630031, overwrite segment 1
with that from most recent successful discharge and turn on segment 2
(lower single null). Note that shot# 1030630031 has three different topologies
programmed into its segments which will be used today:

Segment 2 - Lower null discharge, 5.4 tesla, 0.78 MA,
NL04 = 0.6 (actual), Left gap = 13 mm (@ 1s),
Right gap = 9 mm (@ 1s)

Segment 3 - Upper null discharge, 5.4 tesla, 0.77 MA,
NL04 = 1.3 (actual), Left gap = 16 mm (@ 1s),
Right gap = 9.5 mm (@ 1s)

Segment 4 - Double null discharge, 5.4 tesla, 0.78 MA,
NL04 = 0.6 (actual), Left gap = 14 to 16 mm (@ 1s),
Right gap = 12 - 16 mm (@ 1s)
with slight oscillation between SNU/SNL topology
This shot has feedback on SSEP. See Wolfe for details.

For all shots, we want left gap to be 12 mm and right gap to be 15 mm
This will allow the ISP to reach the separatrix and provide a reasonable
SOL width at the outer midplane to look at flows. Gas set-up for the
NINJA plenum will be handled by diagnosticians. All shots are nominally
0.8 MA, 5.3 tesla discharges with no RF heating or conditioning.

Shot#1-3 (SNL)
Reload shot#1030630031, importing recent segment 1. Turn segment 2 on (lower
single null).
Program NL04 = 0.8x10^20 m^-2
Increase right gap by 6 mm. Decrease left gap by 1 mm.
Check probe targeting and strike-point locations.

Shot#4-6 (SNU)
Turn off segment 2, turn on segment 3 (upper single null)
Program NL04 = 0.8x10^20 m^-2
Increase right gap by 5 mm. Decrease left gap by 4 mm.
Check probe targeting.

Begin density scan with four shots at each density, 2 in SNU and 2 in SNL.

Shot#7,8 - NL04 = 0.6, SNU

Switch to SNL
9,10 - NL04 = 0.6, SNL
11,12 - NL04 = 1.0, SNL

Switch to SNU
13,14 - NL04 = 1.0, SNU
15,16 - NL04 = 1.2, SNU

Switch to SNL
17,18 - NL04 = 1.2, SNL

Begin density scan in DN configuration.
----------------------------------------
Shot#19,20 (DN)
Turn on segment 4
Program NL04 = 0.8x10^20 m^-2
Can proportional gain on SSEP be decreased to remove x-pt oscillations?
Increase right gap by 3 mm. Decrease left gap by 3 mm.
Check probe targeting.

21,22 - NL04 = 0.6, DN
23,24 - NL04 = 1.0, DN
25,26 - NL04 = 1.2, DN
---------------------------------------

Run Summary

The run got off to a slow start with computer problems.After a delay of about
an hour the first plasma shot was run (Shot 2, Shot 1 was a no power shot.)
Then there were a few fizzles intermixed with plasma shots, but then things
settled down and a string of good shots, useful for the miniproposal were
obtained. At shot 14, things became erratic with shots lost due to data
acquisition problems. At this point the machine seemed to settle into an
every-other-shot mode with plasmas interspersed with fizzles. This continued
and actually got worse as the fizzles got more persistent.Three shots in
a row fizzled, 24-26. Unfortunately,with this intermittancy,only about
half of the run plan could be accomplished.

Scorecard: 16 full plasma shots, 2 no power shots, 9 fizzles, 1 dud.


Session Leader Comments
Nov 14 2003 08:40:28:490AMBrian Labombard1031114 Run Plan

MP#335 - Edge plasma flows in upper versus lower x-point discharges

Purpose:
The primary purpose of these experiments is to investigate
the sensitivity of the magnitude and direction of the parallel plasma
flows (routinely observed in the edge plasma) to the magnetic
geometry, in particular upper, lower and double-null configurations.

This MP has been attempted 2 times before: 1030619 - only got 5
data-quality discharges (see run_summary_1030619), 1030630b (1/2 day) - got
11 good shots but the FSP probe was dead - no flow information there
(see run_summary_1030630b). The goal today is to execute the shot plan
called out in the MP with all diagnostics working.

Approach:
We will run a series of matched plain 'vanilla' 0.8 MA, 5.3 tesla ohmic
L-mode discharges, in upper and lower single-null and balanced double-null
configurations. A simple density scan will be performed, allowing contact
to be made with data from previous runs in SNL discharges which show that
the flow speed depends on plasma density. Mach flow will be recorded with
the ASP, FSP, and ISP probes operated in a 'mach' mode. The ISP probe will be
scanned 180 degrees to record 'upstream' and 'downstream' conditions', allowing
us to infer the flow near the inner wall. The Chromex spectrometer will look
at toroidal fiber telescope views of the inner and outer SOL, recording He+1
emission resulting from local helium puffs. Core rotation of Argon
impurities will be monitored with the HIREX spectrometers.

Shot Plan:
Start with a reload from shot# 1030630031, overwrite segment 1
with that from most recent successful discharge and turn on segment 2
(lower single null). Note that shot# 1030630031 has three different topologies
programmed into its segments which will be used today:

Segment 2 - Lower null discharge, 5.4 tesla, 0.78 MA,
NL04 = 0.6 (actual), Left gap = 13 mm (@ 1s),
Right gap = 9 mm (@ 1s)

Segment 3 - Upper null discharge, 5.4 tesla, 0.77 MA,
NL04 = 1.3 (actual), Left gap = 16 mm (@ 1s),
Right gap = 9.5 mm (@ 1s)

Segment 4 - Double null discharge, 5.4 tesla, 0.78 MA,
NL04 = 0.6 (actual), Left gap = 14 to 16 mm (@ 1s),
Right gap = 12 - 16 mm (@ 1s)
with slight oscillation between SNU/SNL topology
This shot has feedback on SSEP. See Wolfe for details.

For all shots, we want left gap to be 12 mm and right gap to be 15 mm
This will allow the ISP to reach the separatrix and provide a reasonable
SOL width at the outer midplane to look at flows. Gas set-up for the
NINJA plenum will be handled by diagnosticians. All shots are nominally
0.8 MA, 5.3 tesla discharges with no RF heating or conditioning.

Shot#1-3 (SNL)
Reload shot#1030630031, importing recent segment 1. Turn segment 2 on (lower
single null).
Program NL04 = 0.8x10^20 m^-2
Increase right gap by 6 mm. Decrease left gap by 1 mm.
Check probe targeting and strike-point locations.

Shot#4-6 (SNU)
Turn off segment 2, turn on segment 3 (upper single null)
Program NL04 = 0.8x10^20 m^-2
Increase right gap by 5 mm. Decrease left gap by 4 mm.
Check probe targeting.

Begin density scan with four shots at each density, 2 in SNU and 2 in SNL.

Shot#7,8 - NL04 = 0.6, SNU

Switch to SNL
9,10 - NL04 = 0.6, SNL
11,12 - NL04 = 1.0, SNL

Switch to SNU
13,14 - NL04 = 1.0, SNU
15,16 - NL04 = 1.2, SNU

Switch to SNL
17,18 - NL04 = 1.2, SNL

Begin density scan in DN configuration.

Shot#19,20 (DN)
Turn on segment 4
Program NL04 = 0.8x10^20 m^-2
Can proportional gain on SSEP be decreased to remove x-pt oscillations?
Increase right gap by 3 mm. Decrease left gap by 3 mm.
Check probe targeting.

21,22 - NL04 = 0.6, DN
23,24 - NL04 = 1.0, DN
25,26 - NL04 = 1.2, DN
Nov 14 2003 10:19:00:087AM1031114002Brian LabombardShot - 2 Lower null, NL04 = 0.8
ASP, FSP, ISP scanning at 0.75, 0.95, 1.15 s
ASP, FSP far out
ISP scanning near sep.

Next shot: reduce outer and inner gaps, deeper probes
Nov 14 2003 11:56:05:177AM1031114004Brian LabombardShot - 4 Lower null, NL04 = 0.8
ASP, FSP, ISP scanning at 0.75, 0.95, 1.15 s
ASP not in far enough
FSP looks ok
ISP a bit over-inserted
Nov 14 2003 11:57:09:723AM1031114006Brian LabombardShot - 6 Lower null, NL04 = 0.8
ASP, FSP, ISP scanning at 0.75, 0.95, 1.15 s
ASP looks ok
FSP looks ok
ISP a bit over-inserted
Nov 14 2003 12:01:57:010PM1031114007Brian LabombardShot - 7 Lower null, NL04 = 0.8
ASP, FSP, ISP scanning at 0.75, 0.95, 1.15 s
ASP looks ok
FSP looks ok
ISP nice data (reduced bias voltage)
Nov 14 2003 12:27:25:567PM1031114008Brian LabombardShot - 8 Upper null, NL04 = 0.8
ASP, FSP, ISP scanning at 0.75, 0.95, 1.15 s
ASP looks ok
FSP too far out
ISP nice data

Next shot: increase outer gap
Nov 14 2003 12:31:57:960PM1031114009Brian LabombardShot - 9 Upper null, NL04 = 0.8
ASP, FSP, ISP scanning at 0.75, 0.95, 1.15 s
ASP looks ok
FSP too far out
ISP nice data

Next shot: repeat with probes deeper
Nov 14 2003 12:50:07:333PM1031114010Brian LabombardShot - 10 Upper null, NL04 = 0.8
ASP, FSP, ISP scanning at 0.75, 0.95, 1.15 s
ASP looks ok
FSP looks ok
ISP nice data

Next shot: goto NL04 = 0.6
Nov 14 2003 01:16:19:043PM1031114011Brian LabombardShot - 11 Upper null, NL04 = 0.6
ASP, FSP, ISP scanning at 0.75, 0.95, 1.15 s
ASP looks ok
FSP looks ok
ISP nice data

Next shot: repeat
Nov 14 2003 01:17:03:150PM1031114012Brian LabombardShot - 12 Upper null, NL04 = 0.6
ASP, FSP, ISP scanning at 0.75, 0.95, 1.15 s
ASP looks ok
FSP looks ok
ISP nice data

Next shot: go back to lower null at same NL04 = 0.6
Nov 14 2003 01:40:15:920PM1031114013Brian LabombardShot - 13 Lower null, NL04 = 0.6
ASP, FSP, ISP scanning at 0.75, 0.95, 1.15 s
ASP too far out - large outer gap
FSP looks ok, could be deeper
ISP nice data

Next shot: repeat with desired gaps
Nov 14 2003 02:23:15:437PM1031114015Brian LabombardShot - 15 Lower null, NL04 = 0.8 (intended to be 0.6)
ASP, FSP, ISP scanning at 0.75, 0.95, 1.15 s
ASP looks good
FSP looks good
ISP nice data

But no magnetics data
Nov 14 2003 02:44:52:737PM1031114018Brian LabombardShot - 18 Lower null, NL04 = 0.6+
ASP, FSP, ISP scanning at 0.75, 0.95, 1.15 s
ASP looks good
FSP looks good
ISP nice data


Next shot: NL04 = 1.0
Nov 14 2003 03:14:33:273PM1031114019Brian LabombardShot - 19 Lower null, NL04 = 1.0
ASP, FSP, ISP scanning at 0.75, 0.95, 1.15 s
ASP looks good
FSP looks good
ISP nice data


Next shot: goto upper null, same density
Nov 14 2003 04:00:37:950PM1031114020Brian LabombardShot - 20 Upper null, NL04 = 1.0
ASP, FSP, ISP scanning at 0.75, 0.95, 1.15 s
ASP could be deeper
FSP could be deeper
ISP nice data

Next shot: repeat
Nov 14 2003 04:57:49:197PM1031114023Brian LabombardShot - 23 Upper null, NL04 = 1.0
ASP, FSP, ISP scanning at 0.75, 0.95, 1.15 s
ASP looks good
FSP looks good
ISP nice data

Next shot: go to NL04 = 1.2
Nov 14 2003 04:58:25:493PM1031114027Brian LabombardShot - 27 Upper null, NL04 = 1.0
ASP, FSP, ISP scanning at 0.75, 0.95, 1.15 s
ASP looks good
FSP looks good
ISP nice data

Physics Operator Comments
Nov 14 2003 09:35:34:953AM1031114001Ron ParkerShot 1 will start with segment 1 from 1031106001, segment 2 from 1030630031.
It turned out to be a no-power shot due to hybrid problems. Shot 002 should be
a plasma shot.

More delays due to data system -- Josh is working on the problem.
Nov 14 2003 10:18:07:803AM1031114002Ron ParkerShot 2 ran well. Next shot: inner gap reduced by 1mm, outer gap reduced by 4 mm.
Nov 14 2003 10:31:36:703AM1031114003Ron ParkerShot 3 was a fizzle. Initial fill might have been too high.
No magnetics data. We are again on hold due to data system problems.
Meanwhile, the initial fill has been reduced by 2 ms.
Nov 14 2003 11:03:05:917AM1031114004Ron ParkerShot 004 ran well with gaps that were close to required.


Nov 14 2003 11:08:48:390AM1031114005Ron ParkerShot 5 was a dud. Fill pressure still seems high, 0.083 mT.

Gas will be reduced by 2 ms.
Nov 14 2003 11:24:55:340AM1031114006Ron ParkerShot 6 ran well. For a few shots, no RF, no gate valve closure. We're trying
to get out of the every other shot mode.
Nov 14 2003 11:43:19:400AM1031114007Ron ParkerAgainst all odds, the shot went off well.

Now we'll move to upper null discharge as outlined in the run plan.
Nov 14 2003 12:15:03:510PM1031114008Ron ParkerShot 8 ran well, some tuning of the right gap will be done for next shot.
Nov 14 2003 12:29:14:053PM1031114009Ron ParkerShot 9 ran well. We lost interferometer at ~1.3 s.
Sump pump problem will cause a short delay.

No change for next shot.
Nov 14 2003 03:03:49:937PM1031114010Ron ParkerShot 10 ran well. For next shot, we will lower the density to 0.6e20 m-2
Nov 14 2003 01:11:43:493PM1031114011Ron ParkerShot 11 ran well, one more at this density and configuration.
Nov 14 2003 01:10:58:820PM1031114012Ron ParkerShot 12 ran well. We will now shift back to lower null plasmas as in the first 7 shots.

The density will be the same as for these last upper null shots.
Nov 14 2003 01:39:29:873PM1031114013Ron ParkerShot 13 ran, but did not reproduce the desired gaps. Shot 7, segment 2 was
reloaded for next shot.
Nov 14 2003 01:44:49:470PM1031114014Ron ParkerShot 14 fizzled, probably due to effect of disruption on previous shot.


Try again next shot.
Nov 14 2003 02:34:42:087PM1031114015Ron ParkerShot 15 ran, but with programmed nel4=0.8, not 0.6. Next shot will have nel4=0.6.
Argon pulse increased from 40 to 50 ms. Magnetics and other data were lost for
Shot 15. Another delay due to problems with magnetics data. Shot 16 will be a
no power shot.
Nov 14 2003 02:36:56:183PM1031114016Ron ParkerShot 16 was a no power shot.
Nov 14 2003 02:36:24:557PM1031114017Ron ParkerShot 17 was a fizzle.
Nov 14 2003 03:06:38:563PM1031114018Ron ParkerShot 18 ran well, with nel4=0.6e20m-2. Next shot the density will be
increased to nel4=1.0 m-3.
Nov 14 2003 03:15:47:963PM1031114019Ron ParkerShot19 ran well, with nel4=1.0e20m-2.
Next shot, switch back to upper single null, as in shot 12.

Density will be increased to nel4=1.0e20 m-2.
Nov 14 2003 03:25:20:080PM1031114020Ron ParkerShot 20 ran well, achieving target parameters. Next shot will have the same settings.
Nov 14 2003 03:31:03:270PM1031114021Ron ParkerShot 21 fizzled. Try again next shot.
Nov 14 2003 03:53:09:773PM1031114022Ron ParkerShot 22 also was a fizzle. We'll increase the fill by 10%.
Nov 14 2003 04:01:04:577PM1031114023Ron ParkerShot 23 went off OK, despite glitch on current rise.

Next shot: nel4 will be programmed for 1.2e20 m-2.
Nov 14 2003 04:22:01:467PM1031114024Ron ParkerShot 24 fizzled.
Nov 14 2003 04:26:14:580PM1031114025Ron ParkerShot 25 fizzled. We'll increase the fill pressure again to .07 mT.
Nov 14 2003 04:44:36:030PM1031114026Ron ParkerShot 26 fizzled.
Nov 14 2003 04:45:35:560PM1031114027Ron ParkerShot 27 ran well.
Nov 14 2003 05:03:23:187PM1031114028Ron ParkerShot 28 fizzled.

Engineering Operator Comments
ShotTimeTypeStatusComment
108:55:57:890AMPlasmaBadShot cycle failure
209:58:02:147AMPlasmaOk
310:14:33:350AMPlasmaOk
410:42:12:353AMPlasmaOk
510:58:44:850AMPlasmaOk
611:11:16:440AMPlasmaOk
711:31:43:080AMPlasmaOk
811:56:44:553AMPlasmaOk
912:11:29:313PMPlasmaOk
1012:36:19:590PMPlasmaOk
1112:53:34:870PMPlasmaOk
1201:06:52:427PMPlasmaOk
1301:19:33:920PMPlasmaOk
1401:39:21:687PMPlasmaOk
1501:51:42:913PMPlasmaOk
1702:25:11:813PMPlasmaOk
1802:37:35:150PMPlasmaOk
1902:58:41:823PMPlasmaOk
2003:14:43:930PMPlasmaOk
2103:27:30:440PMPlasmaOk
2203:40:00:607PMPlasmaOk
2303:53:23:180PMPlasmaOk
2404:05:51:937PMPlasmaOk
2504:18:19:620PMPlasmaOk
2604:30:51:300PMPlasmaOk
2704:43:34:123PMPlasmaOk
2804:56:25:867PMPlasmaOk