Electron-Impact Liquid-Jet Water-Window X-ray Sources

Detta är en avhandling från Stockholm : Universitetsservice US AB

Sammanfattning: This Thesis describes the development and characterization of a soft x-ray liquidjet-anode electron-impact source. With a water-jet target the primary emission is the O K? line at 525 eV. This is close to the lower edge of the water-window, a spectral region lacking simple laboratory sources. In the hard x-ray regime electronimpact microfocus sources have matured and are simple, stable, reliable, and inexpensive. It would be beneficial if this source concept could be used also for soft x-ray generation.  Spectral measurements of a 120 W, 30 keV electron beam focused on a 20 ?m water jet show an x-ray intensity of up to 3.2 × 1012 ph/(s×sr×line). Combined with source size measurements up to 50 W a maximum brightness of 3.5 × 109 ph/(s×?m2×sr×line) is reported. This makes the brightness comparable to the compact discharge-plasma sources presently used for soft x-ray microscopy. The source appears to be scalable another order of magnitude which would make the brightness equal to that of the laser-plasma sources.