Theoretical approach of the photoinjector exit aperture influence on the wake field driven by an electron beam accelerated in an RF gun of free-electron laser “ELSA”

Development and Simulation Studies of a Novel Electromagnetics Code

“…Similar to the methods developed by Salah et al [25,26], we have developed analytical solutions to Maxwell's equations for the rf photoinjector in the presence of boundary conditions, such as the flat cathode and conducting cavity walls. The arbitrary longitudinal current densities of the beam are assumed to be in axially boundary conditions with an arbitrary cross-section.…”

“…There are several studies which analyzed the electromagnetic fields based on Green's function methods [25,26,21]. These references [25,26] In application for high-power microwave sources, an extended Green's function technique will be discussed in Chapter 5. This method will include the effect of transverse currents of bunched charged particle beams.…”

“…There have been analytical approaches to solve the electromagnetic fields in a rf photoinjector [25,26], which are based on the Green's function method. These approaches solve the Maxwell's equation in the presence of the boundary conditions, such as a cathode and the cavity walls, using two different gauge conditions.…”

“…There are a variety of methods which can be utilized for including the effects of irises. For example, in Ref [25,26],. the authors expanded the space-charge fields in each region of injector space, i.e., before and after the iris, using eigenfunctions which locally satisfy the correct boundary conditions.…”

Time dependent formulation of the energy loss by an accelerated intense electron beam just emitted by the cathode of RF-FEL photoinjector

“…It cannot be kept for the just emitted beam like those encountered in photoinjectors, where the photoemitted electrons experience an extremely quick acceleration from thermal to multipleMeV energy. Therefore, the density is far from being uniform [14][15][16][17]. A theoretical treatment of this situation, based on the normal mode analysis model in a pill-box cavity will be the aim of this paper.…”