  The antineutrinos of the neutron rich 8Li isotope is characterized by hard
and good defined spectrum - averaged energy is 6.5 MeV and maximal - up to 13
MeV. An intensive antineutrino source with such parameters can be unique
instrument for neutrino investigations and especially for search of sterile
neutrinos. The 8Li can be produced by (n,gamma)-activation of 7Li isotope. The
proposed scheme of the antineutrino source is based on the lithium blanket
around the accelerator neutron producting target. We propose to use heavy water
solution of the lithium hydroxide instead of lithium in metallic state. Such
solution for lithium blanket substance ensure the large perspectives in real
steps for creation of this installation. An analyses of neutron fields in the
blanket and distribution of 8Li creation allows to propose the next principal
steps in the construction of the lithium blanket. We propose to enclose the
blanket volume isolating it's central part with more high 8Li production. This
solution allows to decrease the necessary mass of very pure 7Li isotope (with
admixture of 6Li - 0.0001) up to 120-130 kg (i.e., to decrease in ~ 150 times
compare to variant of lithium blanket in metallic state). The source become
more compact - the linear dimension is decreased in 2.5 times (up to 1.3 m) and
this is very essential for sterile neutrino search taking in mind the
indication on difference ~1 eV2 between squared mass of sterile and active
neutrinos.
