This proposal describes a program of research to be carried out by Prof. Karl Krushelnick of the University of Michigan during a 12 month visit to ENSTA-LOA in Paris. He will join the world-leading laser plasma acceleration group of Dr. Victor Malka at LOA. This research involves the use of the highest power, shortest pulse laser systems available for producing relativistic plasma waves capable of accelerating electron beams to GeV range energies. This is a rapidly growing field of research and Prof. Krushelnick has significant experience in diagnostic development and experimental design for short pulse laser interaction experiments. During this visit he will be involved in development of new techniques for increasing the energy and charge of the electron beams produced in the experiments as well as studying the plasma physics of the beam generation. This will involve the use of new diagnostic systems (such as XUV spectroscopy, particle probing, and spectrally resolved imaging techniques) developed at Michigan. In addition such compact relativistic beams are potentially excellent sources of high energy radiation for many applications, and during his visit he will be involved in the development of new techniques for enhancing the properties of these sources, including improvements in the flux and reduction of the pulse duration. Measurements to understand the physics of the radiation process by detailed measurement of the spectrum produced will also be undertaken.