Home.News.Activity.Publications.Contact us.

© 2010-2014 SarFTI NRNU MEPhI

Русская версия

High-power Pulsed Electrophysics

Phase metal-insulator transition under effect of pulsed currents and its use in current opening switches and current limiters

 

Theory of high-power solid-state opening switches

(The work has been carried out in the frameworks of the Project №829 of International Scientific and Technical Center under support of Los Alamos National Laboratory, USA.)

 

Joule heating of a substance takes place at a magnetic field penetration into a conductor. A non-linear current wave, propagating into the condutor,  could form if the phase transition metal-insulator of the first order takes place at temperature increase in this substance. Solid solutions (V1-XCrX)2O3 are examples of such substance. This phenomenon could be used for development of high-power solid-state opening switches. Stability of a metal-insulator phase interface, which moves with medium heating, is an key issue.

 

Current lines on the perturbed interface metal-insulator (the metal phase is on the right, the interface moves from left to right, and the perturbation grows).

Results of a numerical simulation of imetal-insulator nterface propagation in non-uniform medium (lines show isotherms; figure to the right is a moment of the current breaking)

 

Experimental study of the phase metal-insulator transition kinetics at high-power pulsed currents flow

(The work has been carried out in the frameworks of the Project № 1109 of International Scientific and Technical Center under support of Los Alamos National Laboratory, USA.)

 

A bench for investigation of the phase transition and nonlinear magnetic field penetration in (V1-XCrX)2O3 has been developed. In the lower picture: 1 is the source current, 2 is the current in the load, the dotted line is the current in an active element (V1-XCrX)2O3.