High power laser interaction with clusters

Response of clusters to laser radiation depends on the laser parameters lik e wavelength, pulse duration, field, and so forth. At moderate laser intens ities, I similar to 10(12) W/cm(2), using a laser beam of wavelength 1.06 m um and 10-ns pulse duration, we have studied X-ray emission spectra from al uminum clusters of diameter 0.4 mum and gold clusters of 1.25 mum. Aluminum clusters show a different spectra compared to bulk material whereas gold c lusters evolve towards bulk gold. Results are analyzed on the basis of clus ter dimension, laser wavelength, and pulse duration. At higher laser intens ities greater than or equal to 10(18) W/cm(2), clusters undergo Coulomb exp losion, giving rise to energetic electrons and ions. Here we discuss the po ssibility of harnessing these energetic particles for heating a small volum e of the precompressed DT fuel to ignition condition relevant to fast ignit ion. Preliminary results are discussed.