IBS effects in a wiggler-dominated light source

Intra-beam scattering (IBS) is often thought of as a fundamental limitation to achieving lower emittance and hence higher brightness in modern storage ring light sources. However, as we show in this paper analytically and by simulations using ZAP and SAD codes, this limitation may no longer be relevant in a wiggler- dominated 3rd generation light source. Instead, lowering the emittance by increasing the amount of wiggler radiation does not result in significant IBS-induced emittance blow-up, as higher beam density (and IBS rates) is compensated by faster radiation damping. We show that under some practical assumptions the relative ratio of the emittance including the IBS effect to the emittance at zero current is emittance-independent.