Characteristics of capillary discharge Ne-like Ar soft X-ray laser

Soft X-ray laser has some convenient properties such as short wavelength, monochromaticity and coherency. Aiming at the development of a table-top size laser, we have designed, fabricated and tested a soft X-ray device, which uses a capillary discharge to achieve neon-like argon lasing (J = 0 - 1, /spl lambda/ = 46.9 nm). The pulsed power generator consists of a Marx generator, a pulse transformer, a pulse forming line, a gap switch and a capillary made of Al/sub 2/O/sub 3/ ceramics. Previously, spike output has been observed, when operating the device with a predischarge current of 5 to 15 A and a main discharge current of 9 to 35 kA with a rise time of 55 ns in an argon gas pressure range from 100 to 800 mTorr. When the distance between the end of capillary and the X-ray diode detector changed, the amplitude of spike signal does not change. This indicates that the spike signal shows directivity, which is a property of the laser. In the present study, spectroscopic measurement has been conducted using a grazing incidence spectrometer. The line at 46.9 nm has been observed. The X-ray diode measurement has also been conducted by varying the capillary length,. The result shows that the laser output exponentially increases with increasing the capillary length.