Diagnostic of electron temperature from bremsstrahlung in overdense targets

TL;DR

This paper introduces models for diagnosing electron temperature from bremsstrahlung in overdense targets, proposing an effective temperature functional that accurately reflects the electron energy distribution and distinguishes true hot electron effects from noise artifacts.

Contribution

It presents a novel effective temperature functional that overcomes limitations of traditional temperature measures in bremsstrahlung spectra, validated through simulations and experiments.

Findings

The effective temperature functional accurately identifies hot electron components.

Models agree well with Monte Carlo simulations and experimental data.

The approach exposes false heating effects caused by noise.

Abstract

Models for characterization of laser-accelerated electron via its produced bremsstrahlung are provided for both thin and thick targets. An effective temperature functional is proposed to overcome the so-called cold and hot "temperatures" in the emission spectra, which are shown not to describe the underlying electron energy distribution. In contrast, this functional allows for identifying the real effect of a hot electron component. A false "heating" effect due to added noise is also exposed. The models are shown to be in good agreement with Monte Carlo simulations, as well as in good agreement with other experimental methods when applied to experimental data.