DIRECT INJECTION SUPERSONIC CLUSTER BEAM SOURCE FOR FT-ICR STUDIES OF CLUSTERS

A miniaturized pulsed supersonic beam source has been developed using laser vaporization of a computer-controlled target disk, producing intense beams of cluster ions with excellent repeatability and control. Due to its small size and narrow pulse width, the entire source is adequately pumped by a single 170 l /s turbopump. The resultant vacuum quality permits this source to be attached to a Fourier transform ion cyclotron resonance apparatus (FT-ICR) such that the supersonic cluster ion beam is directly injected. The result is a powerful but simple FT-ICR instrument of wide applicability. The new source is suited as well for a variety of other uses such as molecular beam epitaxy.