Effective stress of the SSC 80 K synchrotron radiation liner in a quenching dipole magnet

This paper describes the effective stress on a proposed SSC beam tube. The new issue for the Collider compared to earlier accelerators is the combination of synchrotron radiation with the 4.2-K bore tube of the superconducting magnets. One design option is to use a liner within a bore tube to remove the radiated power and the accompanying photodesorbed gas that impair the beam tube vacuum. Design of the SSC 80-K synchrotron radiation liner requires vacuum luminosity lifetime=150 hours and liner electrical conductivity, /spl sigma/*t>2E5 /spl Omega/-1. The bimetallic liner tube is subjected to cool down and eddy current loads. The liner tube is a two-shell laminate with Nitronic-40 steel for strength and a copper inner layer for low impedance to the image currents induced by the circulating protons. High electrical conductivity of the copper layer is essential for minimizing the power losses. Perforated holes are used to remove the photodesorbed gases for vacuum maintenance. The tube is cooled by 80-K lines. Structural design of the liner is not covered by the ASME code. The life of the liner involves structural integrity and keeping the copper laminate within yield stress limits to maintain the high surface finish for minimizing the power losses. The copper layer stress governs the structural design of the liner. The liner tube analysis is a three dimensional nonlinear stress problem. Thermal transient cool down stress is not considered in this analysis because of the floating support design of the liner. This analysis will address the axial thermal stress, nonaxisymmetrical eddy current loads, dynamic and nonlinear material effect on the liner that have not. Been considered in publications on beam tube structural analyses.<>