Generalizing the Method of Images for Complex Boundary Conditions : Application on the LHC Beam Screen

Abstract

This paper seeks to show that the beam screen of the LHC has an important effect on the electric field of the LHC beam, a few tens of sigmas away from its center. To do so, we develop two new methods for finding the effect of a complex conducting boundary for boundary value problems in electrostatics. Both methods are based on a generalization of the method of images and require low computing power. The result is an exact solution to the problem of a discretized conducting boundary, which we take to be an approximation of the real solution. As an application, we compute the total electric field inside the LHC beam screen and show that neglecting the effect of the conducting boundary is only accurate to 1% for locations closer than 10$\sigma$ from the center of the beam, and only accurate to 10% for locations closer than 30$\sigma$.