Elytt design and manufacturing superconducting magnet for ILL
SuperSUN is a new instrument project proposed by the ILL’s Group for Nuclear and Particle Physics (NPP). It consists in the construction and installation of a high-density source for ultra-cold neutrons (UCNs). UCN production is based on the well-established conversion of cold to ultra-cold neutrons via inelastic scattering in isotopically purified superfluid helium held at a temperature below 0.6 K.
The superconducting magnetic trap provides a magnetic multipole reflector around the superfluid-helium converter with the purpose to repel low field seeking UCNs from the material walls of the converter vessel. This leads to a strong reduction of UCN losses due to UCN collisions with these walls and results in a high density of UCNs in the converter.
The magnetic trap cryostat contains a superconducting multipole magnet and the electrical feedthroughs for injecting the current into the coils. The magnet will be immersed in a bath of liquid helium equipped with a cold head for re-condensation. The 3-m long converter vessel will be situated in the cold bore of the magnet. The inner surface of the cold bore will be coated with neutron absorbing material to shield the magnet against neutrons scattered out of the converter. The cold bore will also act as the inner thermal screen with very low heat load to the converter tube due to the bore being close to liquid-helium temperature.