from the conferences organized by TANGER Ltd. provisional website
Sub-nanosecond electrical breakdown in dielectric liquids is of vital interest for applications, e.g. in high-voltage insulation, high-current switching and electric field-cell interactions. Liquid dielectrics in strong nonuniform electric fields are under influence of electrostrictive force that tends to move the fluid into the regions with higher electric field. If the voltage rise is fast enough(nanoseconds), the liquid does not have enough time to be set into motion in order to reduce the internal stress. In this case the electrostrictive force induces significant stress in the bulk of the liquid which is manifested as a negative pressure. At certain threshold, the negative pressure causes cavitation ruptures of the fluid. Subsequently, free electrons can be produced by emission from the surface inside the cavity and accelerated to energies exceeding the energy for ionization of water and thus, contribute to electrical breakdown of water.We present numerical model, which gives us basic ingredients necessary to study interaction of accelerated electrons with liquid water during sub-nanosecond electrical breakdown. We aim to determine geometrical conditions in electrode vicinity needed for electron multiplication and subsequent build up of space charge, for which we propose to use Monte Carlo software Geant4-DNA. Using of proper simulation techniques could enable us to explain some experimentally observed properties of sub-nanosecond electrical breakdown in liquid water.Keywords: Liquid water, sub-nanosecond electrical breakdown, cavitation, negative pressure, Geant4-DNA
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