A high-energy, long-pulse, large-volume, electron-beam driven KrF laser was constructed in order to carry out laser–matter interaction experiments with metals, ceramics and polymers in the ultraviolet spectral range at 248 nm. This laser delivers up to 200 J in 400 ns. In the framework of applications such as machining or shock-hardening, the knowledge of mechanical phenomena is very important in order to understand and maximize laser parameters. An experimental investigation was carried out into the mechanical effects (specific impulse and pressure) in direct ablation and in confined ablation mode.