Simulating dark current effects in linear collider structures

With the requirement for particle accelerators getting higher and higher in energy and accelerating gradients many phenomena become more and more dominant. One of them is the dark current, resulted from collective movement of electrons which by quantum effects leave cavity walls and cause additional thermal heatup as well as many undesired effects in the linac. In this paper we present the simulation of two multicell cavities for the DESY/THD S‐band collider and the TESLA collider project. The electrons are emitted at different phases of the accelerating fields. The trajectories are calculated for several accelerating gradients with no space charge effects taken into account. From this the deposited thermal energy inside the cavity walls as well as the dark current rate are determined.