Superconducting magnetic systems with forced circulation of subcooled helium for synchrotrons

The superconducting magnetic systems (SMS) of an accelerator-storage complex (ASC) for 2000 GeV and the accelerator complex Nuklotron are described. Presented are the results of calculation and mockup testing of SMS on the basis of dipole and quadrupole electromagnets, whose windings are cooled by forces circulation of helium refrigerated to 4.3 K. SMS of ASC consists of two stages of a ring magnet of 12 km long, which makes it possible to form colliding beams of protons with the energy of 800 GeV x (800-2000) GeV. The total refrigerating capacity for MSM of ASC is 45 kW at 4.2 K. The Nuklotron SMS consists of 48 dipole and 64 quadrupole magnets. The principal difference between the Nuklotron SMS and the ASC SMS consists in the absence of a void with reverse two-phase helium. The total thermal loads on the cryogenic system of Nuklotron with due regard for the circulation pump losses, are 1.8 kW at 4.2 K