Selective sequential 2n decay of /sup 14/C states populated by /sup 13/C+n

In the double-differential time-of-flight spectrum of emerging neutrons from neutrons incident on /sup 13/C, a sharp substantital peak was observed whose energy remained constant as the incident neutron energy varied over at least 1.2 MeV. The results show that this peak is almost surely the secondary neutron group in the sequential 2n decay of levels in /sup 14/C/sup */ where the primary neutron decay (inelastic scattering) is to the (5/2)- (7.547 MeV) level in /sup 13/C/sup */ which then decays via a 3-MeV secondary neutron to the ground state of /sup 12/C. This reaction appears to be very selective in that from 15.8 MeV to 18.4 MeV the states of /sup 14/C/sup */ do have substantial overlap with /sup 13/C/sup */ ((5/2)-, 7.547 MeV) coupled to a neutron, whereas from 8 to 18.4 MeV they appear to have small or negligible overlap with the positive parity states of /sup 13/C/sup */ in this region