Design of a twin-aperture 4 T curved dipole based on high current hollow superconducting cables for the NICA collider at JINR

NICA (Nuclotron-based Ion Collider fAcility) is the new accelerator complex currently under construction at JINR. The facility is aimed to provide collider experiments with heavy ions up to uranium with a centre of mass energy up to 9 GeV/u and an average luminosity up to 1027 cm-2s-1. The collisions of polarized deuterons are foreseen too. The accelerator complex includes two injector linacs, a superconducting booster synchrotron, a 6 GeV/u superconducting synchrotron (Nuclotron) and a collider consisting of two storage rings. Curved superconducting 4 T Cosine(θ)-style dipoles based on a hollow Nuclotron-type cable are chosen for the collider ring lattice. The twin-aperture dipole consists of two vertically assembled cold masses operating at T = 4.5 K placed inside a common thermal shield and a common cryostat. The dipole good field aperture is fixed to 60 mm. The maximum cable operating current is about 17 kA. The field ramp is set to 1 T/s.