An Analysis of the coherent synchrotron radiation effect in an energy-recovery linac by first-order transfer matrix

Hajima, Ryoichi

We propose a novel approach to the analysis of the coherent synchrotron radiation (CSR) effect on beam dynamics in energy-recovery linacs (ERL). Since an ERL return-arc consists of a large number of dipole and quadrupole magnets, it is not a practical way to search an optimum design by time-consuming particle simulations. We show that a first-order transfer matrix can be applied to calculate the emittance growth due to the CSR in the linear regime, weak CSR limit. The optimum design of ERL arcs such as triple-bend achromat lattice is easily obtained by matrix calculation. As an example, optimization of a 3GeV ERL arc is presented.