Under the illustrative preceding σzf=20μm and kpσzf=1choices, E0≃25.6 GV m−1 and Lp≃390/ηm. TODO — a unique numerical length inherits the missing compression/density specification and additionally requires a usable wake amplitude/loading factor η or driver information.A driver energy per proton alone does not fix its bunchpopulation or accelerating gradient.