Title: AWAKE readiness for the study of the seeded self-modulation of a 400\,GeV proton bunch,
Abstract: AWAKE is a proton-driven plasma wakefield acceleration experiment. % We show
that the experimental setup briefly described here is ready for systematic
study of the seeded self-modulation of the 400\,GeV proton bunch in the
10\,m-long rubidium plasma with density adjustable from 1 to
10$\times10^{14}$\,cm$^{-3}$. % We show that the short laser pulse used for
ionization of the rubidium vapor propagates all the way along the column,
suggesting full ionization of the vapor. % We show that ionization occurs along
the proton bunch, at the laser time and that the plasma that follows affects
the proton bunch. %