Cryogenic Design and Thermal Analysis of EIC Central Detector (ePIC) Solenoid Magnet (MARCO)

Abstract

The electron ion collider physics program utilizes a 2.0-T superconducting magnet at the heart of its electron-proton/ion collider detector system. This approximately 3.5-m-long and 2.84-m-diameter warm bore magnet has a 20-ton cold mass, which is conduction cooled using liquid helium at 4.5 K. A closed-loop active thermosiphon system is chosen to facilitate cooling and to maintain a minimum of 2-K temperature margin on the peak operating temperature (4.7 K) of the superconductor. This article presents the cryogenic design of the cooling system and the thermal analysis of the solenoid. A computational fluid dynamics model was developed to quantify the performance of the two-phase closed thermosiphon system and predict the temperature gradient on the cold mass.