Experimental evidence of the rapidly increasing neutron yields in proton-induced reaction on heavy target across 0.6-1 GeV

The independent yield distribution of the Hg isotopes, measured for the reaction of 600MeV O-18 projectile with a Pb-nat. target, is converted to O-18+Pb-208 system and is compared with an Hg-isotope distribution from the spallation reaction of 1 A GeV Pb-208 on proton. The comparison shows the differences between the two distributions on the production cross sections, isotope-distribution widths as well as their shapes. A great increase of the neutron-deficient Hg isotope yield with increase of bombarding energies of protons from 600MeV to 1 GeV is derived. This fact results in an experimental evidence for rapid increasing neutron yields with rising proton bombarding energy from 0.6 GeV to 1GeV.