Structure of the XUV emitting regions in a laser produced plasma

The XUV spectra emitted by plasma produced by focusing a ruby laser on plane targets of carbon and beryllium have been observed with a novel stigmatic spectrograph fitted with a toroidal mirror. The observations have been made both side-on on the expanding plasma and end-on looking inside the crater. In the latter case the intensity emitted is very large and the lines broadened indication electron densities approacing the critical density at 2.2×10²¹ cm^-3. The relative intensity of resonance lines, free-bound and free-free continua and He-like and Li-like satellites has been determined. In particular the latter satellites appear to arise only from the region inside the crater.