High-brightness water-window electron-impact liquid-jet microfocus source

We demonstrate stable high-brightness operation of an electron-impact water-jet-anode soft x-ray source. A 30 kV, 7.8 W electron beam is focused onto a 20 μm diameter jet resulting in water-window oxygen line emission at 525 eV/2.36 nm with a brightness of 3.0x109 ph/(sxμm2xsrxline). Monte Carlo-based modeling shows good quantitative agreement with the experiments. The source has potential to increase the x-ray power and brightness by another 1-2 orders of magnitude and fluid-dynamical jet instabilities is determined to be the most important limiting factor. The source properties make it an attractive alternative for table-top x-ray microscopy.