Ultrafast electron diffraction. Velocity mismatch and temporal resolution in crossed-beam experiments

The time resolution of crossed-beam experiments is explicitly related to velocity mismatch and other beam parameters. Application of this general treatment to ultrafast electron diffraction reveals that a time resolution of approximately 1.4 picoseconds can be achieved under conventional conditions. It is possible to reduce this value by increasing the electron energy, varying the angle between the electron and laser pulses, and reducing the focal width of the laser and the size of the molecular beam.