Soft X-Ray Emission of Continua from Laser Produced Plasmas

Plasmas produced irradiating plane targets of low Z elements with moderate energy (3–10 J) lasers emit considerable amounts of free-free and free-bound continua in the soft X-ray region (10–100 Å) of the spectrum. With intensity calibrated grazing incidence spectrographs an intensity of the order of 108 W sr–1 Å–1 cm–2 emitted by the densest portion of the plasma inside the crater formed at the interaction was determined. This is in good agreement with theoretical predictions for a plasma of predetermined parameters. In case of high Z elements the continuum emitted has a very smooth wavelength dependence