Specifics of Pulsed Magnetic Field Penetration Into Electrodes of Rail-Type Accelerator With Application of the Variable Conductivity in the Surface Layers of Rails at Uniform Acceleration of Solid Armature up to 2.5 km/s (Numerical Investigation in 2-D Model)

The special numerical model of the rail-type accelerator has been used in this article with application of the variable conductivity in the surface layers of rails. In theoretical background of work, there is shown a possibility to compensate a great influence of the velocity of armature growth on the current distribution along the contact surface by gradual increase of magnetic field diffusion coefficient into the rail following with velocity increase. Assuming an armature at constant acceleration, it was possible to recalculate the local electrical conductivity of rail surface as a function of time. The numerical simulation of the nonstationary field induction penetration into electrodes of contact pair has been performed in 2-D approximation using the software Comsol v. 3.5 for velocity growth up to 2.5 km/s. The results of simulation are presented in the view of dynamic picture of induction distribution in the rails and body of armature as well as current density distribution along the contact surface. The work's main conclusion consists of demonstration of how distribution of magnetic induction and current density can be improved due to controlled velocity of the field penetration along the contact surface of rails.