Generation and Applications of Short-Pulse X-ray Radiation

Abstract

This thesis summarizes work using hard X-ray radiation on nanosecond and picosecond timescales. The focus is on the experimental part including detailed descriptions of setups for laser pumped - X-ray probe experiments. X-ray diffraction is sensitive to structural properties on the length scale of chemical bonds. The greatest success of X-ray diffraction lies in the determination of crystal structures, but many other application of X-ray diffraction exist. In this work, this structural probe was used to detect changes in the crystal structure in the form of lattice perturbations and phase transitions. The field of time-resolved X-ray diffraction employs subpicosecond temporal resolution to study ultra-fast processes such as non-thermal melting and coherent optical phonons. This requires rather specialized equipment and setups. An introduction to this and to the time-resolved X-ray diffraction method is provided together with a description of the synchrotron radiation facility beam-line D611 at MAX-lab in Lund, which is dedicated to such experiments. This thesis also describes studies on laser produced plasma at the Lund High-Power Laser Facility. Work with this source started at the High-Power Laser Facility already in 1992. The source was developed as a potential X-ray source for medical applications. This thesis focuses on the laser produced plasma source as a femtosecond source and its characterization. The thesis also contains theory on the phenomena encountered. The theoretical description are intended to provide a basic understanding and guidelines for further reading if the reader is interested in expanding his or her knowledge on the subject