The General Appearance of the Superconducting Magnet System for the Gas-Dynamic Multimirror Trap

The paper presents the evaluation of basic parameters and general appearance of the superconducting magnetic system of the Gas-Dynamic Multimirror Trap - the next-generation magnetic mirror research facility developed by the Budker Institute of Nuclear physics. The major requirements are that the magnetic field would be ramped up from 0.3 to 3 T within 5 seconds, which implies that a special low AC-loss superconducting cable must be chosen for this part of the magnet system. The mirror coils should have the field ~12 T with an aperture exceeding typical of large-bore NMR magnets. In accordance with these requirements the optimized magnet system has been evaluated. The system can have modular design and consists of a set of 12 coils with NbTi superconductors and 4 coils made of Nb
₃
Sn superconductor. Preliminary choice of superconducting cables and basic superconductors for the windings has been substantiated. The estimation of stability margins for all coils demonstrated that both NbTi and Nb
₃
Sn coils have enough stability margins, including the operation of NbTi coils at fast changing current. The study demonstrated the feasibility of the optimized superconducting magnet system for the Gas-Dynamic Multimirror Trap with the use of modern low T
_c
superconductors and state-of-the-art superconducting magnet technologies.