  Proton beam dumps are prolific sources of charged and neutral pions, enabling
a powerful technique to search for dark matter, axions, sterile neutrinos,
tests of short baseline anomalies, and precision measurements of coherent
nucleus scattering neutrinos (CEvNS). The Lujan neutron elastic scattering
center at the Los Alamos Neutron Science Center (LANSCE) consists of an
800-MeV, short-pulse, 100-kW proton and spallation neutron source where such
searches are ongoing with the Coherent CAPTAIN Mills (CCM) 10-ton, liquid argon
detector. The employment of fast timing coincidence of the beam with the
detector is used to identify signals and reject background. The current beam
time width is 300 ns with an intensity of $3.1 \times 10^{13}$ protons per
pulse at 20 Hz. With upgrades to the Proton Storage Ring (PSR), the beam time
width may be compressed to 30 ns with minimal intensity loss, allowing an
increase in the signal to background (S/B) of more than 100 and an increase in
the sensitivity for dark matter and sterile neutrino searches of an order of
magnitude. This can be achieved with PSR accelerator upgrades on a time scale
of a few years and at a modest cost.
