arXiv subjects

S. M. H. Mirhoseini

Publications and source records attributed to S. M. H. Mirhoseini.

3 recordsLinked to original sources

arXiv2017

Passive and active electromagnetic stabilization of free-surface liquid metal flows

Free-surface liquid metal flows tend to be uneven due to instabilities and other effects. Some applications, however, require constant, uniform liquid metal thickness. This is for example the case of liquid walls in nuclear fusion reactors. With this motivation, here we present experimental results on the stabilization of a free-surface flow of Galinstan. The flow was sustained by an electromagnetic induction pump featuring rotating permanent magnets. Evidence is reported of the flowing Galinstan layer becoming flatter in the presence of a sufficiently strong magnetic field, either alone (passive stabilization) or in combination with an electrical current passing through the liquid metal (active stabilization). The results are interpreted in terms of an effective viscosity and effective gravity, respectively.

physics.plasm-ph↗

arXiv2016

Resistive sensor and electromagnetic actuator for feedback stabilization of liquid metal walls in fusion reactors

Liquid metal walls in fusion reactors will be subject to instabilities, turbulence, induced currents, error fields and temperature gradients that will make them locally bulge, thus entering in contact with the plasma, or deplete, hence exposing the underlying solid substrate. To prevent this, research has begun to actively stabilize static or flowing liquid metal layers by locally applying forces in feedback with thickness measurements. Here we present resistive sensors of liquid metal thickness and demonstrate jxB actuators, to locally control it.

physics.ins-det↗

arXiv2016

Space- and Time-resolved Resistive Measurement of Liquid Metal Wall Thickness

In a fusion reactor internally coated with liquid metal, it will be important to diagnose the thickness of the liquid at various locations in the vessel, as a function of time, and possibly respond to counteract undesired bulging or depletion. The electrical conductance between electrodes immersed in the liquid metal can be used as a simple proxy for the local thickness. Here a matrix of electrodes is shown to provide spatially resolved measurements of liquid metal thickness in the absence of plasma. First a theory is developed for mxn electrodes, and then it is experimentally demonstrated for 3x1 electrodes. The experiments were carried out with Galinstan, but are easily extended to Lithium or other liquid metals.

physics.plasm-ph↗