Author/Authors :
Ruber، نويسنده , , R.J.M.Y and Blom، نويسنده , , H. Calen، نويسنده , , H and Fridén، نويسنده , , C.-J and Larsson، نويسنده , , A and Norman، نويسنده , , G and Yamamoto، نويسنده , , A and Yamaoka، نويسنده , , H and Makida، نويسنده , , Y and Kimura، نويسنده , , N and Tanaka، نويسنده , , K and Iida، نويسنده , , M and Ohhata، نويسنده , , H and Hirabayashi، نويسنده , , H and Takasu، نويسنده , , N and Nawrot، نويسنده , , A، نويسنده ,
Abstract :
An ultra-thin-walled superconducting warm bore solenoid has been developed for the WASA detector set-up at the CELSIUS accelerator of the The Svedberg Laboratory (TSL), Sweden. It gives a central magnetic field up to 1.3 T, and can be operated in persistent mode. The total thickness of the superconducting coil is 9 mm with an inner diameter of 554 mm and an energy-to-cold-mass ratio of 6 kJ/kg. The total wall thickness is a record low 0.18 in units of the radiation length (X0) including the material of the cryostat. The solenoid has been successfully operated in combination with the WASA detector set-up since 1998.
lenoid has a coil split in two parts with a central gap of 40 mm for a tube guiding small frozen hydrogen target pellets into the accelerator beam. The solenoid is fixed by glass-fibre supports. It has a vacuum vessel with 1 mm thick corrugated walls of aluminium and it has high-purity aluminium strips in axial direction to improve heat conduction. The solenoid is enclosed by an iron yoke which shields the detector readout electronics from the magnetic field. A diagnostics, control and safety system has been developed for the solenoid itself and for the associated cryogenics.
