Mass and velocity distributions of low energy cluster beams

We have recently generated several low energy cluster beams by using a laser vaporization source and a pulsed He stream. This has been done both for covalent (silicon and carbon) and metallic (gold) materials. In this work we present a simple procedure to carefully measure the speed and speed distribution of the obtained clusters with the help of an orthogonal time of flight mass spectrometer. Results show average speed values in the range 700 - 1000 m/s with a mild variation by changing the gas backing pressure and the cluster mass inside each cluster train. Detailed speed distributions for each cluster's mass will be given. (c) 2005 Elsevier B.V. All rights reserved.