Four-frame holographic probing system for plasma density measurement (invited)

Abstract

An important upgrade of UV holographic interferometry is now in use. Many hundreds of laser fusion-type target plasmas have been probed at KMS Fusion, Inc. using the holographic technique. The data obtained with this diagnostic include high-resolution images and plasma electron density distributions at various probe times. The diagnostic system now produces a sequence of four interferograms of an evolving plasma. The times of the 20-ps pulses in the sequence are fully adjustable and known within 10 ps. The experiments to which this diagnostic has been adapted will be described along with details of problems and their solutions. Selected sets of recent interferograms of plasmas produced by irradiation of thin foils will be presented along with their inversions.