Steps toward MTOR Experimental Investigations for ALIST Project Where we stand? This Step: Investigation of Conducting Wall Effects on MHD Film Flow:in a magnetic field region resembling a combined NSTX toroidal and surface normal fields as seen by an outboard divertor lithium film. Stronger MHD effect derived from surface normal field Preliminary data show some increases (up to a factor of 3) in film height as results of MHD opposing forces Need further effort on film height quantification

Is the remaining 3rd component of axial field critical? Toroidal current from surface normal field interact with B axial produces a force normal to liquid surface (pull Ga off the surface?) Adding an axial field component to the 2D-setup and study MHD film flow characteristics critical?

Impact of Conducting Wall Test Article Width MTOR conducting test article size limited by the available gap required for producing prototypical field strength Current test article size of 5 cm wide is narrower than NSTX LSM size of 40 cm wide conductance ratio  Stronger boundary layer effect from gradient toroidal field? The wall is less electrically resistive than the Hartmann layer.  Less MHD drag from surface normal field Correspondingly, a relevant question concerns whether a mid-wall divider needed in NSTX LSM in order to cut down surface normal field induced toroidal current and the resultant flowing opposing MHD drag. Effects of simultaneous area expansion with uphill flow C 5 cm > C 40 cm

Time-varying magnetic field on MHD film behavior The ramp up time for the NSTX magnet is about 0.6 second required to increase TF current through the 36 TF turns to its 71.2 kA maximum design value, which provides the full 0.6 Tesla Toroidal Field at major radius R=0.854 m. Also, at the full current, the maximum "Equivalent Square Wave" time is only 1.3 seconds; any more than 1.3 seconds at 71.2 kA might damage the TF coil due to overheating.- Woolley Need to optimize MTOR film test article layout to minimize the effect (and thus provide useful data to NSTX LSM design) Time (second) B

MTOR Near Term Plan for ALIST May - September 03  Continue to acquire quantitative data such as film height map  Begin to assess Time-varying magnetic field effect Study of the effects of prototypical field ramp up/down on MHD film flow coupled with flow area expansion September 03 and forward  Begin to assess a half (or full) LSM evaluation study