Concept of curved magnetically guided liquid lithium target without a back plate for IFMIF

Curved magnetically guided lithium target (MGLT) without a back plate was newly proposed in light of simplified structure, easy maintenance and enhanced availability and performance for international fusion materials irradiation facility (IFMIF). It can replace conventional lithium target with a curved material back plate under the most severe condition on neutron irradiation. Magnetic field suited for the curved MGLT is produced in combination of a couple of radiation-proof resistive coils and reduced activation ferritic/martensitic steel (F82H) parts (yokes, ducts/nozzles and high flux test module (HFTM)). Shape of the magnetic field becomes curved automatically in the target region by setting HFTM closely to MGLT. Characteristics of the lithium flow on MGLT was analyzed in detail by two dimensional equations of motion with the magnetic field calculated by the Poisson Superfish code. The necessary magnetic flux density at the target region was found to be about 0.5 T to fulfill the IFMIF target conditions, i.e., lithium flow speed of 15 m/s, curvature radius of 1–1.6 m and flow thickness of 0.025 m. A narrow gap (a few mm) between MGLT and HFTM could be controlled by adjusting the coil current. Future subjects for further development of this concept were identified.