  Supernova neutrinos can easily be detected by a spherical gaseous TPC
detector measuring very low energy nuclear recoils. The expected rates are
quite large for a neutron rich target since the neutrino nucleus neutral
current interaction yields a coherent contribution of all neutrons. As a matter
of fact for a typical supernova at 10 kpc, about 1000 events are expected using
a spherical detector of radius 4 m with Xe gas at a pressure of 10 Atm. A world
wide network of several such simple, stable and low cost supernova detectors
with a running time of a few centuries is quite feasible.
