We have observed plasma jets from laser-irradiated gold disk targets. The structures originate from low-intensity regions of the incident laser beam but propagate much faster than similar density surfaces from higher-intensity regions. The material is both cold and dense, as evidenced by its emission of soft x rays and absorption of hard x rays.

• Received 21 June 1989

DOI:https://doi.org/10.1103/PhysRevLett.63.2737