Performance and Operational Upgrades of X-ray Streak Camera Photocathode Assemblies at NIF

摘要

X-ray streak cameras are used at the National Ignition Facility for time-resolved measurements of inertial confinement fusion metrics such as capsule implosion velocity, self-emission burn width, and x-ray bang time (time of brightest x-ray emission). Recently a design effort was undertaken to improve the performance and operation of the streak camera photocathode and related assemblies. The performance improvements include a new optical design for the input of UV timing fiducial pulses that increases collection efficiency of electrons off the photocathode, repeatability and precision of the photocathode pack assembly, and increase the input field of view for upcoming experiments. The operational improvements will provide the ability to replace photocathode packs between experiments in the field without removing the diagnostic from the Diagnostic Instrument Manipulator (DIM). The new design and preliminary results are presented.