An Abundance of Extremely Large Clusters as a Target for Intense Laser-Matter Interaction

Abstract

The advent of very intense, short-pulse lasers changed dramatically the field of laser-matter interaction. The interest in new forms of target brought clusters to the forefront as a very promising and unique medium. Here, extremely large Xe or CO2 clusters embedded in an abundance of smaller ones were formed and subsequently irradiated by intense laser pulses (less than or similar to 10(19) W/cm(2)) to demonstrate the specific character of such a medium and its suitability for intense laser-matter interaction. Emission of short-wavelength radiation quantified in the spectral range known as the "water window&apos;&apos; constituted the reference for the target performance. The clusters were formed in a double-stream gas-puff equipped with a gas reservoir cooled down to 245 K and backed by a low-to-moderate pressure of <= 12 bar. The obtained atomic/molecular compounds, mostly of an irregular shape and of an average diameter similar or equal to 2.4 +/- 0.5 mu m in the case of Xe and similar or equal to 2.0 +/- 0.4 mu m for CO2, have been imaged by optical microscopy while the size was determined by the standard scattering method. A scenario explaining the formation of such clusters has been proposed. The interaction results show that a photon/particle source can be copious when based on the developed target technology with an abundance of the extremely large clusters. These clusters enable also the experiments with a single-cluster target.