Some FEL beamlines, especially those based on echo-enabled harmonic generation (EEHG), are sensitive to small, random jumps in energy generated by incoherent processes such as intra-beam scattering (IBS) and incoherent synchrotron radiation (ISR). Here, we examine the energy jumps caused by IBS when the local energy spread is a negligible factor compared to the transverse momentum spread, as is typical in accelerators. A simulation tool for modeling chicanes incorporating the effect of IBS is described.
