Design of a New Horizontal Test Cryostat for Scrfcavities at the Uppsala University

At Uppsala University, the FREIA facility for researchand development of new accelerators and associatedinstrumentation, is presently in construction. Associatedto a new Helium Liquefier, a Horizontal Test Cryostat willbe used for high power RF tests of completely equippedSC cavities. This paper presents the main characteristicsof the cryostat. Two types of cavities have beenconsidered for test purpose: SC elliptical cavities forfuture free electron lasers and SC cavities for highintensity proton accelerators. A special valve boxincluding a subcooling stage and power coupler coolingwith supercritical Helium supply have been designed, fortemperature operation ranging from 2 K to 4.2 K. Thisfacility will play an essential role in the development andtest of cavities, couplers and cryomodules for the ESSproject. High power RF sources will be installed in orderto allow unique and complete tests of spoke cavities andcryomodules at high nominal peak power