Formation of thin superconducting films by means of ultra-high vacuum arc

In order to study the vacuum are technique for obtaining high quality superconducting Nb films an UHV experimental set-up with planar are source was designed and constructed at the ``Tor Vergata'' University of Rome under an INFN research grant and within the framework of a collaboration between the University of Rome ``Tor Vergata'' and the A.Soltan Institute for Nuclear Studies at Swierk. The paper describes the UHV arc.apparatus and discusses the main parameters of are discharges as well as the first results of measurements of the superconducting film samples quality.