Emission properties of a fast capillary discharge soft X-ray source

The capillary discharge is of great interest as a high brightness, short pulse XUV and soft X-ray source. Intense light emission from the visible to the soft X-ray region can be produced with very high brightness due to the high aspect ratio. Both broadband continuum and narrow band line radiation can be produced. Lasing gain in long capillary discharges have been demonstrated in a number of experiments. To increase the plasma temperature the pressure has to be decreased. The difficulties at low pressure are the tendency for the discharge to be formed on the surface of the wall and long build-up time of the discharge. This introduces significant materials from the wall discharge which is not directly under external control. To overcome these problems we have developed a device for intense XUV production which combines the features of a transient hollow cathode discharge with the characteristics of the capillary discharge. In this paper, some of the pulsed power aspects of this pulsed hollow cathode capillary discharge are presented together with some of the results obtained. The potential underlying the understanding, as well as the control, of the operating regime of a high temperature capillary discharge open up several areas of innovative research. The implication of the successful realization of a table-top X-ray laser in both research and application could not be over emphasized