  New particle acceleration schemes open up exciting opportunities, potentially
providing more compact or higher-energy accelerators. The AWAKE experiment at
CERN is currently taking data to establish the method of proton-driven plasma
wakefield acceleration. A second phase aims to demonstrate that bunches of
about $10^9$ electrons can be accelerated to high energy, preserving emittance
and that the process is scalable with length. With this, an electron beam of
$O$(50 GeV) could be available for new fixed-target or beam-dump experiments
searching for the hidden sector, like dark photons. The rate of electrons on
target could be increased by a factor of more than 1000 compared to currently
available, leading to a corresponding increase in sensitivity to new physics.
Such a beam could also be brought into collision with a high-power laser and
thereby probe the completely unmeasured region of strong fields at values of
the Schwinger critical field. An ultimate goal is to produce an electron beam
of $O$(3 TeV) and collide with an LHC proton beam. This very high energy
electron-proton collider would probe a new regime in which the structure of
matter is completely unknown.
