Generation and application of ultrafast X-ray sources

Pulses at soft X-ray wavelengths with a duration of less than 1.5 ps were produced by focusing high-intensity, ultrafast visible laser pulses onto a solid. Reflectivity measurements indicate that the laser pulses are absorbed by a plasma formed just inside the surface of the solid before expansion occurs. The observed emission spectrum is characteristic of a high-temperature, short-lived, high-density plasma. Applications of the ultrafast X-ray pulses, including an X-ray laser scheme, are discussed.<
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