The Physics of Extremely Low Energy Nuclear Recoils for Dark Matter and Coherent Neutrino Scattering*

Direct detection of dark matter and detection of neutrinos via coherent scattering (CENNS) are venues in which we are interested in detecting extremely low energy nuclear recoils. While these nuclear recoils are difficult to detect, there has been much recent progress in this area. I survey some of the most recent work on the subject including the use of thermal neutron scattering to produce controlled nuclear recoil events at around 100 eV recoil energy. We also discuss how thermal neutrons can also pose background issues for dark matter and CENNS in the case where the flux is unknown.