\label{fig:beamstrahlung} The beam-energy spectrum for TLEP (red) for $\sqrt{s} = 240$ GeV. For illustration, the beam-energy spectrum expected in presence of beamstrahlung is shown for the ILC (black) at the same centre-of-mass energy. The $L_{0.01}$ value is the fraction of the integrated luminosity produced within 1\% of the nominal centre-of-mass energy. The effect of initial state radiation (common to TLEP and ILC, but physics-process dependent) is not included in this plot.