Self-magnetic insulation in vacuum for coaxial geometry

Abstract

Magnetic insulation obtained by employing the magnetic field of the line current in coaxial vacuum-transmission lines is studied in experiments on two different relativistic electron-beam accelerators, spanning the voltage range 0.4–10 MV. Effective magnetic insulation at fields up to 1.3 MV/cm is demonstrated. The self-limiting impedance is measured and compared to a number of theories for magnetic insulation and it is found that none of the ’’standard’’ theories successfully describes the data. However, computer simulations using a self-consistent two-dimensional particle code give good agreement with the experimental data, as does a proposed modification of the parapotential flow model.