High Radiation Environment Nuclear Fragment Separator Magnet

Magnets in the fragment separator region of the Facility for Rare Isotope Beams (FRIB) facility would be subjected to extremely high radiation and heat load. Critical elements of FRIB are the dipole magnets which select the desired isotopes. Since conventional NiTi and Nb3Sn superconductors must operate at ~4.5 K, the removal of the high heat load generated in these magnets will be difficult. Moreover, the dipole coils are required to have a large curvature which has never been accomplished in magnets made with brittle superconductor. This dipole must be removable remotely because of the extremely high radiation environment.High Temperature Superconductor (HTS) can withstand high radiation and heat loads that will be encountered. HTS is shown to be radiation resistant and can operate in the 30-50 K temperature range where heat removal is an order of magnitude more efficient than at 4.5 K. The large curvature will be obtained using one of two novel methods described in the narrative. The dipole will be designed so that coils can be replaced by robotic handling.In phase I we will develop a magnetic and conceptual design of an HTS 25bend magnet with curved coils for use in the FRIB fragment separator. We will wind and test at least one curved coil at 77 K. We will also simulate particle tracking in the vicinity of this magnet to determine the radiation and heat load environment which will be used in the thermal analysis of the magnet design. We will perform a magnetic, thermal and structural analysis for this magnet.Commercial Applications and Other Benefits: High temperature superconducting magnets will have an immediate use as an essential part of the FRIB facility. The expertise gained from this project will enable the design of magnets for accelerator applications in high radiation and high heat load environments such as near the targeting stations for a muon collider or neutrino factory