  The photon spectrum in macrocoherent atomic de-excitation via radiative
emission of neutrino pairs (RENP) has been proposed as a sensitive probe of the
neutrino mass spectrum, capable of competing with conventional neutrino
experiments. In this paper we revisit this intriguing possibility, presenting
an alternative method for inducing large coherence in a target based on
adiabatic techniques. More concretely, we propose the use of a modified version
of Coherent Population Return (CPR), namely double CPR, that turns out to be
extremely robust with respect to the experimental parameters, and capable of
inducing a coherence close to 100% in the target.
