A new type of X-ray sources was invented in Sweden and is commercially available from company Excillum. In these sources the anode hit by the electrons is a very fast (about 50 m/s) jet of liquid metal e.g. tin or gallium or nitrogen or methanol. The jet is produced by pressing the liquid under high pressure through a nozzle. The diameter of the jet is in the range of only 200 µm and the source point has a size of about 20 µm x 80 µm (vertical x horizontal). When the jet is hit by the accelerated electrons, it partially evaporates. So the power per square centimetre can be much higher (about 1 MW/cm2) compared to X-ray tubes with standing or rotating anodes.