The curiosity of researchers to find novel characteristics and properties of matter constantly pushes for the development of instrumentation based on X-radiation. I present in this thesis techniques for electron spectroscopy based on developments of X-ray sources both in time structure and energy. One part describes a laser driven High-Harmonic Generation source and the application of an off-plane grating monochromator with additional beamlines and spectrometers. In initial experiments, the source is capable of producing harmonics between the 13th and 23rd of the fundamental laser 800 nm wavelength. The intensity in the 19th harmonic, after monochromatization, was measured to be above 1.2·10¹⁰ photons/second with a repetition rate of 5 kHz. 

The development of a chopper system synchronized to the bunch clock of an electron storage ring is also presented. The system can be used to adjust the repetition rate of a synchrotron radiation beam to values between 10 and 120 kHz, or for the modulation of continuous sources. The application of the system to both time of flight spectroscopy and laser pump X-ray probe spectroscopy is shown. It was possible to measure triple ionization of Kr and in applied studies the valence band of a laser excited dye-sensitized solar cell interface. The combination of the latter technique with transient absorption measurements is proposed.

The organic molecule maleic anhydride (MA) and its binding configuration to the three anatase TiO₂ crystals (101), (100), (001) has been investigated by means of Xray Photoelectron Spectroscopy (XPS) and Near Edge X-ray Absorption Fine structure Spectroscopy (NEXAFS). The results provide information on the binding configuration to the 101 crystal. High Kinetic Energy Photoelectron Spectroscopy was used to investigate multilayers of complexes of iron, ruthenium and osmium. The benefit of hard X-rays for ex-situ prepared samples is demonstrated together with the application of resonant valence band measurements to these molecules.

This thesis presents HELIOS, an in-house laboratory for time-resolved pump-probe spectroscopy with extreme-ultraviolet (XUV) probe radiation. A wide span of pump wavelengths can be generated using commercial laser equipment while XUV probe radiation is generated via a high harmonic generation process in a noble gas delivering probe photons with energies between 20 eV and 72 eV. The XUV beam path features a time-preserving monochromator and was constructed and built in-house. HELIOS features an overall time resolution of about 50 fs when using 800 nm pump and 41 eV probe photons. An energy resolution of 110 meV at 41 eV photon energy can be achieved. HELIOS features two beamlines. One µ-focus beamline with an XUV focal size of about 20 µm can be used with experiments that require such a small XUV focal size as well as with different end stations. The other beamline features a semi-permanently mounted end station for angle-resolved photoelectron spectroscopy under ultra-high vacuum conditions.

Experiments demonstrating the usability of HELIOS and the two beamlines are presented. A pump-probe measurement on graphene demonstrates the capability of determining a large part of the k-space in only one measurement due to the use of an ARTOF angle-resolved time-of-flight electron spectrometer. A non-angle-resolved pump-probe measurement on the conducting polymer PCPDTBT demonstrates the high signal-to-noise ratio achievable at this beamline in non-angle-resolved photoelectron-spectroscopy pump-probe measurements. The usability of the µ-focus beamline is demonstrated with time-resolved measurements on magnetic samples employing an in-house-designed spectrometer. These experiments allow the retrieval of element-specific information on the magnetization within a sample employing the transversal magneto-optical Kerr effect (T-MOKE).

Additionally, a Fourier transform spectrometer for the XUV is presented, the concept was tested at a synchrotron and it was used to determine the longitudinal coherence of the XUV radiation at HELIOS.