Strong x-ray emission from high-temperature plasmas produced by intense irradiation of clusters

The interaction of an intense laser pulse with large ({similar_to}100 A) clusters present in pulsed gas jets is shown to produce novel plasmas with electron temperatures far in excess of that predicted by above-threshold ionization theory. The enhanced absorption of the laser light by the dense clusters results in the production of high ion charge states via collisional ionization resulting in strong x-ray emission from the hot plasma. {copyright} {ital 1995} {ital The} {ital American} {ital Physical} {ital Society}.