Photoelectron trajectory analyses of streak tubes

A streak tube is a precision high voltage vacuum photonic device capable of registering the temporal variation of multiple signal channels with subnanosecond resolution. The streak tube has become the vital component of the current time-resolved prompt diagnostics instrumentation system for the Nuclear Test Program. The performance of the streak tube is predominately governed by the trajectory behavior of all the photoelectrons traveling from the photocathode through the deflection region to the phosphor anode. The trajectory analyses require a finite-element-method based on computer program to solve Poisson's equation for potential distribution and to calculate the trajectories. Two codes (GUNSLAC and EBQ) in the CDC-7600 computer were used for the designing of a prototype large-format streak tube, and the evaluation of two existing tubes, RCA-C73435 and ITT-2XIC16. Analyses were performed by varying the electrode's configuration, voltage, photoelectron's energy, emitting orientation and current. Both the computer generated trajectory plots and the numerical data summaries are presented.