 Solution

For a comparison appropriate to this 2012 examination, use the reference-design and conceptual-design targets rather than later revised starting stages:The ILC reference programme included scanning approximately $200$–$500$ GeV and a possible $1$ TeV upgrade. The CLIC 2012 studies included lower-energy construction stages as well as the ultimate multi-TeV machine. These are design goals, not achieved operating luminosities.

Collider luminosity sets the event rate for a process of cross-section $\sigma$ through $dN/dt=\mathcal{L}\sigma$; it is not radiated optical power. ^{[ref] [ref]}