Muons, Inc. was incorporated in 2002 with the specific intent to foster research into a muon collider as a future energy-frontier facility for high energy physics. The new insight was that putting high-pressure gas inside an RF accelerating cavity can supress arcing and breakdown better than vacuum. This puts material into the beam, so it is suitable only for muons, for which it acts as the absorber required for muon cooling. Between 2002 and 2018 Muons, Inc. performed dozens of projects investigating many aspects of muon cooling, muon acceleration, and related topics.
Muons, Inc. was instrumental in galvanizing the HEP accelerator community to re-investigate a muon collider (it had been found wanting in the 1990s). In 2006 Pier Oddone, then Director of Fermilab, created the Fermilab Muon Collider Task Force (MCTF); the first external announcement was in a meeting with Muons, Inc. about one of our proposals to Fermilab. In 2011 the MCTF morphed into the Muon Accelerator Program (MAP), a nationwide program hosted at Fermilab dedicated to research on applications of muon accelerators, specifically a Neutrino Factory and a Muon Collider.
In 2014 the Particle Physics Project Prioritization Panel (P5) determined that muon accelerators were too far in the future to justify current funding, and MAP was terminated soon thereafter. A small remnant remains today for the completion of the MICE experiment at the Rutherford-Appleton Laboratory in the UK.
There has recently been a revival of interest at CERN in a muon collider. We will be happy to discuss this with interested parties; email us at mailto:email@example.com.