Comparison between experiment and computer modelling for simple MILO configurations

Summary form only given, as follows. A detailed comparison of experimental results and computer simulation has been made for a number of simple axisymmetric MILO structures. The study has included conditions of stable oscillations, unsteady oscillations (due to mode competition), secular change due to generator characteristics, and spurious surface effects. Good quantitative agreement has been shown between simulation and experiment except in the case of surface effects, where electron emission from the slow-wave structure becomes important. The presence of electron emission has been tested experimentally by changing the material of the vanes in the structure and computationally by adding space-charge-limited emissions from the vanes. Turning on anode emission in the simulations showed qualitatively the same features as observed in breakdown in experiments.