Performance and Properties of Ultra-Thin Silicon Nitride X-ray Windows

The spectral transmittance of a new generation of SiN based X-ray windows is characterized. The windows are strengthened by low aspect-ratio support grid. As expected for this unprecedented thin window material, the transmittance in the soft X-ray spectral region outperforms the present technologies. A detailed study of the various performance properties of the fabricated SiN X-ray windows is presented. Besides their high transmittance, the windows also have high uniformity, high mechanical strength and good leak tightness. The windows can withstand temperatures from cryogenic range to approximately 250°C. SiN foils are the first real nanotechnology-based choice for the practical realization of X-ray windows and bring the performance to a level that only nanotechnology can offer.