  A continuous cryogenic hydrogen cluster-jet target has been developed for
laser-plasma interaction studies, in particular as a source for the
acceleration of protons. Major advantages of the cluster-jet target are the
compatibility with pulsed high repetition lasers and the absence of debris. The
cluster-jet target was characterized using the Mie-scattering technique
allowing to determine the cluster size and to compare it with an empirical
prediction. In addition, an estimation of the cluster beam density was
performed. The system was implemented at the high power laser system ARCTURUS
and first successful measurements show the acceleration of protons after
irradiation by high intensity laser pulses with a repetition rate of five
Hertz.
