The magnetic field distribution in acceleration gap of magneticaly insulated ion diode

High power nanosecond MIDs with radial magnetic field [1, 2] are effectively used for modification of material surface layer, pulsed deposition of thin metal and semi-conductor films, synthesis of nanoparticles from ablation plasma [3, 4]. To create plasma on the anode, basically, two approaches are used. The first one is pulsed gas introduction in area of the anode with its subsequent ionization [1, 5]. The second one is plasma formation on the surface of dielectric filling on the anode [6, 7]. MID with radial magnetic field (MID with B_r field) and dielectric fillings on the anode is more simple in realization. Its drawback consists in the destruction of fillings during operation. This problem can be solved by the matching of output impedance of high-power pulsed generator and impedance of MID. In work [7] this solution was reached by the use of matching autotransformer set between a double forming line (DFL) of nanosecond generator and MID. The problem of matching as well as durability of dielectric fillings on the anode significantly depends on the magnetic field configuration. Generally the value of magnetic field induction should be more than the value of critical magnetic field (B_cr), which provides larmor radius which is less then anode-cathode (A-C) gap.