A nearly real-time high temperature laser–plasma diagnostic using photonuclear reactions in tantalum

Abstract

A method of measuring the temperature of the fast electrons produced in ultraintense laser–plasma interactions is described by inducing photonuclear reactions, in particular (γ,n) and (γ,3n) reactions in tantalum. Analysis of the γ rays emitted by the daughter nuclei of these reactions using a germanium counter enables a relatively straightforward near real-time temperature measurement to be made. This is especially important for high temperature plasmas where alternative diagnostic techniques are usually difficult and time consuming. This technique can be used while other experiments are being conducted.