Efficiency of magnetically insulated ion diodes

An expression for the ion production efficiency in magnetically insulated ion diodes is derived. The efficiency is shown to be equal to the ratio of Bsub(K) to Bsub(A) where Bsub(K) and Bsub(A) are magnitudes of the magnetic field components tangential to the electrodes at the power feed side of the diode cathode and anode, respectively. This efficiency is related to the diode geometry, current and voltage by simple pressure balance arguments. The application of this model to three generic ion diode types is discussed. Some comparison with numerical simulation is included. (author)