Diagnostic of electron temperature from bremsstrahlung in overdense targets

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.