Insight on the cryogenic suspension and alignment of the 8T superconducting solenoid with iron yoke

Abstract

An 8 T superconducting solenoid was commissioned at the Australian National University to make precision measurements of fusion cross-sections. During operation at high field, forces between the solenoid and the iron yoke that houses it must always be maintained within safe limits and precision location of the solenoid coil with tight tolerances is necessary to achieve this. Thermal contraction of components can impact the locating structure of the solenoid coil, leading to unsafe forces. For effective operation, the solenoid’s magnetic field axis must be aligned with the optical axis of the beam. After overcoming fundamental flaws in the original design, the solenoid was properly mechanically suspended and aligned with an offset of x= 0.3 ± 0.5 mm, y= 0.8 ± 0.3 mm, as measured using an α source. The improvements to this structure allowed successful completion of the first fusion measurements with the 8T solenoidal separator, and demonstrated that it is now ready for a program of fusion measurements.