Reinventing the
Accelerator for
the High-Energy
Frontier
The history of discovery
in high-energy physics has been intimately connected with progress in methods of
accelerating particles for the past 75 years. This remains true today, as the
post-LHC era in particle physics will require significant innovation and
investment in a superconducting linear collider. The choice of the linear
collider as the next-generation discovery machine, and the selection of
superconducting technology has rather suddenly thrown promising competing
techniques -- such as very large hadron colliders, muon colliders, and
high-field, high frequency linear colliders -- into the background. We
discuss the state of such conventional options, and the likelihood of their
eventual success. We then follow with a much longer view: a survey of a new,
burgeoning frontier in high energy accelerators, where intense lasers, charged
particle beams, and plasmas are all combined in a cross-disciplinary effort to
reinvent the accelerator from its fundamental principles on up.