  Neutrons from ($\alpha$,n) reactions through thorium and uranium decays are
important sources of background for direct dark matter detection. The neutron
yields and energy spectra from a range of materials that are used to build dark
matter detectors are calculated and tabulated. In addition to thorium and
uranium decays, we found that $\alpha$ particles from samarium, often the
dopant of the window materials of photomultiplier tubes (PMT), are also an
important source of neutron yield. The results in this paper can be used as the
input to Monte Carlo simulations for many materials that will be used for next
generation experiments.
