Fast capillary discharge device for soft x-ray generation in the “carbon-window” and “water-window” spectral regions

Abstract

The paper presents a compact source of soft X-ray radiation based on a fast capillary discharge developed for “water window” microscopy methods. The central part of the source is the specially designed nanosecond voltage pulse generator capable of operating at a frequency of 600 Hz, with 100 ns pulse duration and energy per pulse 5 J. The discharge is created in a borosilicate capillary non-uniformly filled with gas. The plasma emission spectra obtained for the case of source operation in argon-helium mixture demonstrate well-pronounced lines in the “carbon window” range, in carbon dioxide-lines in the “water window” range. An analysis of the emission spectra in the range of 2–9 nm in cases of different inlet gas pressures made it possible to estimate the degree of ablation of the inner wall of the capillary and to determine the suitable operating pressure range.