The plasma X-ray source (PXS) is developed for the purpose of generating ultra-short X-ray pulses with a duration of less than 100 femtoseconds. For this purpose, a high-energy laser system with a suitable wavelength is used to generate a plasma on the target material by focusing laser pulses with a duration of 10-100 femtoseconds onto a moving copper strip. The intensity can reach more than 10¹⁷ Wcm^-2 in the spot and creates a plasma of the target material. In this plasma, “hot electrons” are accelerated onto the target material by the electric field of the laser. In the case of a copper strip, this causes K-band ionization. These X-ray pulses can be used for time-resolved experiments in the femtosecond and picosecond range, in particular for pump-probe experiments.