  An advanced technique for a two-dimensional real time visualization of
cluster beams in vacuum as well as of the overlap volume of cluster beams with
particle accelerator beams is presented. The detection system consists of an
array of microchannel plates (MCP) in combination with a phosphor screen which
is read out by a CCD camera. This setup together with the ionization of a
cluster beam by an electron or ion beam allows for spatial resolved
investigations of the cluster beam position, size, and intensity. Moreover,
since electrically uncharged clusters remain undetected, the operation in an
internal beam experiment opens the way to monitor the overlap region and thus
the position and size of an accelerator beam crossing an originally
electrically neutral cluster jet. The observed intensity distribution of the
recorded image is directly proportional to the convolution of the spatial ion
beam and cluster beam intensities and is by this a direct measure of the
two-dimensional luminosity distribution. This information can directly be used
for the reconstruction of vertex positions as well as for an input for
numerical simulations of the reaction zone. The spatial resolution of the
images are dominated by the granularity of the complete MCP device and was
found to be in the order of \sigma~100 \mu m.
