Measurement of heating depth of highly-ionized copper from relativistically-intense laser pulses

We will discuss our recent work performing high-resolution (E/ΔE > 5000) X-ray spectroscopy of copper K-shell emission from high-intensity (I ∼10 21 W/cm 2 ) laser experiments using the ALEPH 400 nm laser at Colorado State University. Through measurements of front- and rear-side K-shell fluorescence and hot electron emission, we examine the generation and propagation of energetic electrons in thin foil and layered targets to elucidate the physics of ultra high-intensity, laser-solid interactions and the existence of temperature gradients in heated materials.