Magnetic Alignment and Mechanical Analysis of Superconducting Bending Section for Proton Therapy

Abstract

The last bending section of a proton therapy beam line may be mounted on a rotating gantry to target the cancerous cells of patients from all possible angles. To gain such capability, it is sensible to use superconducting magnets because of their high energy density providing a large reduction in weight. In the following work, a configuration of combined function magnets for rotating gantries is presented. It includes two conventional electromagnets and three superconducting magnets using Nb <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> Sn conduction-cooled at around 4.2 K. For such assembly, an alignment procedure is proposed to ensure that a large beam momentum acceptance can be achieved. Besides this proposal, additional 3D mechanical Finite Element analyses were conducted to check that the structural support of the most critical superconducting magnets made of Nb <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> Sn wires and their coil thermal shields could handle their weight as well as the momentum due to the rotation.