Spiral 2 Cryogenic System for The Superconducting LINAC
Abstract
SPIRAL 2 is a rare isotope accelerator dedicated to the production of high
intensity beams (E = 40MeV , I = 5mA). The driver is a linear accelerator (LINAC) that
uses bulk Niobium made quarter wave RF cavities. 19 cryomodules inclose one or two cavities
respectively for the low and the high energy sections. To supply the 1300W at 4:2K required
to cool down the LINAC, a cryogenic system has been set up. The heart of the latter is a 3
turbines geared HELIAL®LF (ALAT) cold box that delivers both the liquid helium for the
cavities and the 60K Helium gaz for the thermal screens. 19 valve-boxes insure cryogenic
uid distribution and management. Key issues like cool down speed or cavity RF frequency stability
are closely linked to the cryogenic system management. To overcome these issues, modelling
and simulation efforts are being undertaken prior to the first cool down trials. In this paper, we
present a status update of the Spiral 2 cryogenic system and the cool down strategy considered
for its commissioning.