Long self-magnetically insulated power transport experiments

Abstract

Energy and power transport in a self‐magnetically insulated triplate transmission line are examined. The experiments are done on the MITE accelerator (2 MV, 0.4 MA, 40 ns), which is one module of the electron beam fusion accelerator, EBFA I. The transport efficiency is very sensitive to the injection geometry. An abrupt transition at the beginning of the line causes ∼40% power losses through an apparent instability. The growth length of the instability is ∼53 cm in a line with a vacuum wave impedance Z₀=7.6 Ω. A second loss mechanism is associated with an azimuthal asymmetry in the self‐magnetic field near the injection region. Both loss mechanisms were avoided by properly shaping the input to the transmission line and 90% energy transport and ∼100% power transport were achieved.