  We propose a new scheme of producing intense neutron beam whose yields exceed
those of existing facilities by many orders of magnitude. This scheme uses the
recently proposed photon beam extracted from circulating quantum ions, which is
directed to a deuteron target for photo-disintegration. The calculated neutron
energy spectrum is nearly flat down to neV range, except a threshold rise and
its adjacent wide structure. Hence, there exists a possibility of directly
using sub-eV neutrons without a moderator. We shall have brief comments on
promising particle physics applications using this large yield of neutron.
