The mass and energy distributions of fragments formed in Np-237 fission ind
uced by 1- and 5-MeV neutrons have been measured with the aid of a double i
onization chamber featuring Frisch grids. The spectra for the cold fragment
ation of neptunium have been determined for light fragments of energies up
to 117-122 MeV. It has been shown that dominant mass peaks are split. The e
nergy balance of the fission process has been analyzed in the region of col
d fragmentation.