This volume captures the contents of the talks given at the Workshop on Applications of High Intensity Proton Accelerators held at Fermilab Oct 19ndash;21, 2009. This workshop brought together experts from a variety of disciplines to explore new and profound ways proton accelerators can be used in the future. The workshop explored uses of such a proton source for producing intense muon, kaon and neutrino beams as well as using the intense protons for new forms of nuclear reactors that go by the name Accelerator Driven Sub-critical systems that promise to increase our available nuclear fuel supply by orders of magnitude while at the same time solving the nuclear waste problem. Intense proton beams can also be used to produce short-lived nuclear isotopes that are important in the medical industry.

Low energy neutron beams are used to address many questions in nuclear physics, particle physics and astrophysics. The scientific issues include elucidating the nature of time reversal noninvariance; understanding the origin of the baryon asymmetry in the Universe; describing the weak interaction between quarks and between nucleons; understanding the origin of the elements in stellar and big bang nucleosynthesis.This book summarizes how spallation neutron sources work and discuss the advantages of pulsed beams in reducing systematic errors in precision measurements. It also describes recent breakthroughs in ultracold neutron production, together with the physics that will be addressed by the new generation of intense neutron sources.