Spiral 2 cryogenic system overview: Design, construction and performance test

Abstract

International audienceThe new particle accelerator project Spiral 2 at GANIL (“Grand Accélérateur d’Ions Lourds, i.e. NationalLarge Heavy Ion Accelerator) in Caen (France) is a very large installation, intended to serve fundamental research innuclear physics. The heart of the future machine features a superconductor linear accelerator, delivering a beam until20Mev/A, which are then used to bombard a matter target. The resulting reactions, such as fission, transfer, fusion, etc.will generate billions of exotic nuclei. To achieve acceleration of the beam, 26 cavities which are placed insidecryomodules at helium cryogenic temperature will be used. AL-AT (Air Liquide Advanced Technologies) takes part tothe project by supplying cryogenic plant. The plant includes the liquefier associated to its compressor station, a largedewar, a storage tank for helium gas and transfer lines. In addition, a helium recovery system composed of recoverycompressor, high pressure storage and external purifier has been supplied. Customized HELIAL LF has been designed,manufactured and tested by AL-AT to match the refrigeration power need for the Spiral 2 project which is around 1300W equivalent at 4.5 K

Improvement of Magnet and Cavities cooling at Heavy Ion or Rare Isotopes Accelerators due to Application of sub-cooled Superfluid Helium

“…At FRIB and present designs, these components are actively cooled at two temperature levels, i.e. 5-8K and 40-80K [2][3][4][5][6][7][8][9][10]. In some cases, this significantly complicates the overall cryogenic process scheme [15].…”

“…Accelerators with superconducting (sc) cavities find wide applications as "user" machines, for example, proton linacs (SNS, ESS), heavy ion linacs (FRIB, ISAC-II, Spiral-2, ISOLDE upgrade, ATLAS), linac-based Free Electron Lasers or Energy Recovery Linacs (FLASH, XFEL, Jlab-FEL/ERL, DIAMOND, SOLEIL, Taiwan Light Source, Beijing Light Source) and also several ones are considered for the future or are under constructions, e.g. Lighthouse accelerator, Netherlands, Pohang Accelerator Laboratory, Korea, Shanghai High Repetition Rate XFEL, China, as well as for High Energy one, like LHC [1][2][3][4][5][6][7][8][9][10][11][12]. Though all accelerators are operated at quite different operational conditions, the acceleration gradient has been permanently increased in order to accelerate beams to higher energies.…”