Analytical Formulae for the Loss Factors and Wakefields of a Rectangular Accelerating Structure

Wakefields in a rectangular accelerating structure can be calculated in time domain by directly solving Maxwell's equations by a 3D code. In this paper, we will give analytical formulae to calculate the synchronous modes' loss factors. From these analytical formulae on can get the delta function wakefields. The relations between the loss factors (wakefields) and the structure geometrical dimensions are well established. These analytical expressions of loss factors can be used also in a single rectangular resonant cavity. It is shown that the potential application of a rectangular accelerating structure is to accelerate a flat beam in a linear collider.