Bulk effects in the coherent inelastic scattering of ultracold neutrons

With the use of a theory developed earlier, bulk effects in ultracold neutron coherent inelastic scattering are considered both for solid and liquid target samples related to energy and momentum exchange with phonon and diffusion-like modes. For the neutron in a material trap, differential and integral probabilities for the energy transfer per bounce are presented in a simple analytic form which exhibits parameter dependence. As an example, the theoretical values for the ultracold-neutron loss rate from a storage bottle with Fomblin-coated walls and stainless-steel walls are evaluated. A possible contribution from incoherent inelastic scattering is discussed.