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The inverse triax diode is a low‐impedance, high‐power electron beam diode. A magnetically unbalanced electron flow in the outer gap, which results in an outward pinch, distinguishes this design. Particle code simulations show that this flow has two possible patterns, depending on the presence or absence of an anode plasma. A model for the beam dynamics based on anode plasma formation and incorporating the simulation results is developed. We compare the predictions of the model to experimental results, including time‐resolved x‐ray pinhole photographs obtained with a framing x‐ray pinhole camera, and find reasonable agreement.

Operation of a new type of high‐power electron diode, the bidirectional voltage‐dividing (BVD) diode, has been demonstrated on a 1‐MV, 2.5‐MA, 20‐ns accelerator. This diode consists of a forward‐ and an inverse‐triaxial diode in series. The diode impedance and electron flow pattern agreed reasonably well with particle‐in‐cell code calculations. The radiation spectrum was measured using two different diagnostics, a differential absorption spectrometer and the time‐projection Compton spectrometer. Operating at a voltage of 850–1000 kV, the BVD diode produced a bremsstrahlung spectrum similar to that produced by a standard diode operating at 350–500 kV.