As simple as it seems, the multi-TeV LHC beams will allow for the most
energetic fixed-target experiment ever performed. Such an experiment,
tentatively named AFTER for “A Fixed-Target ExperRiment”, gives access
to new domains of particle and nuclear physics, complementing that of
collider experiments, in particular that of Brookhaven's Relativistic
Heavy Ion Collider (RHIC) and the projects of Electron-ion colliders
(EIC). The instantaneous luminosity achievable with AFTER using typical
targets would surpass that of RHIC by more than 3 orders of magnitude.
This provides a novel testing ground for QCD at unprecedented laboratory
energies and momentum transfers. I will report on the recent progresses
on the project AFTER@LHC, in particular on the physics case and on the
possibilities for the beam extraction.