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A synchrotron is a stadium-sized structure costing hundreds of millions of euros, to which scientists from all over the world fly by plane and wait for months for a few days of measurement time. AGH in Krakow has just launched a laboratory that provides comparable quality of the X-ray beam - in a room with an area of 36 m2 at the Faculty of Physics and Applied Computer Science. The heart of the installation is a lamp that has never existed in Poland before: MetalJet with an anode made of liquid metal, capable of generating X-ray radiation with an intensity that ordinary X-ray machines cannot even approach.

Liquid metal instead of solid

Every X-ray machine works on the same principle: a stream of electrons hits the material (anode), and the material emits X-ray radiation. The more energy you provide to the electrons and the more densely you focus the beam on the anode, the brighter and more precise the radiation you will obtain.

The problem with regular X-ray machines is that the anode is made of a solid metal - usually copper, molybdenum or tungsten. The electron beam hits the solid material and heats it. If you supply too much power, the anode melts, damages and loses quality. This is a physical ceiling that cannot be overcome: the brightness of a conventional X-ray source is limited by how much heat a piece of solid metal can withstand.

Instead of a solid anode, the MetalJet lamp uses a stream of liquid metal (an alloy of gallium, indium and tin), which flows at a speed of up to 100 m/s. The metal is already molten, so there is nothing to melt. The stream continually regenerates, providing fresh anode material. A beam of electrons can bombard it with a force that would destroy any solid anode, and the liquid metal accepts this load without degradation, operating 24/7, with a break for maintenance once a year.

The beam generated by the MetalJet lamp reaches a brightness up to 100 times higher than conventional sources with the same focal size. In selected energy ranges, this parameter approaches the values characteristic of synchrotron beams - so far obtained only in large-scale storage rings with a circumference of hundreds of meters and requiring numerous maintenance.

36 square meters versus the pitch

So far, Polish scientists who needed an X-ray beam with synchrotron parameters had to apply for measurement time in large European centers: ESRF in Grenoble, DESY in Hamburg, SOLARIS in Krakow (a Polish synchrotron, which, however, specializes in ultraviolet and soft X-ray radiation, not in hard X-rays up to 160 keV). The application process takes months, measurement time is limited to a few days, sample transport requires logistics, and each change in experiment parameters means a new application and new waiting.

The laboratory at AGH is fundamentally changing the current model of conducting advanced X-ray research. Polish scientists gain access to infrastructure that allows for flexible planning of experiments, repeated measurements and testing of hypotheses without the time constraints typical of synchrotrons. Acquiring a complete data set that previously required an overnight measurement session now takes less than an hour, even for extremely small samples.