Coherent synchrotron radiation analysis for the photoinjected energy recoverylinac and uvfel projects at the NSLS

摘要

When an electron bunch is compressed either in a chicane or a bending arc, theCSR will induce an energy redistribution along the bunch. Such energy redistribution will affect the longitudinal emittance as a direct consequence. It will also excite betatron oscillation due to the chromatic transfer functions, and hence a transverse emittance change. For the proposed Photoinjected Energy Recovery Linac (PERL) at the NSLS, bending arcs will be used for bunch compression, while for the UV Free Electron Laser (UVFEL), chicane compressors are used. Since it is normally thought to be deleterious, the CSR effects are analyzed carefully for both projects. It turns out that the CSR effect could be serious, hence schemes to reduce the effect are investigated. Such schemes are incorporated into the PERL arc design. For the UVFEL, chicane parameters are carefully chosen to minimize the CSR effects.