Simulations and measurements of bilamellar streak tubes

Abstract

Particle-in-cell simulations of a picosecond-resolution bilamellar streak tube are described, and the results are compared to measurements of key specifications. A novel laser diode setup with a small focal spot has been used to investigate the sensitive width of the photocathode, a previously unpublished parameter. Simulations have shown that the tubes, while performing at high spatiotemporal resolution, have electron efficiencies of just 1.6% due to the action of the temporal focusing electrode, contributing to an effective dynamic range of around 10. The virtual photocathode created by this electrode was predicted to be 144 µm, in excellent agreement with the measured width of 136 µm. A simple method to improve the tube’s dynamic range by narrowing the slit width is investigated and shown to have a modest simulated improvement.