Electrofission of (sup 239) pu in the energy range 7-12 mev

Abstract

The electrofission cross section of ²³⁹Pu(e,f) is measured between 7 and 12 MeV. The data are analyzed by means of the virtual photon formalism, assuming that E1, E2 (T=0), and M1 transitions are involved. Using known estimates for the E1 and E2 (T=0) fission strengths, it is deduced an M1 fission strength of 19 ±4μ²N concentrated near the fission barrier (between 5.4 and 5.8 MeV). The levels of the ²³⁹Pu transition nucleus are theoretically obtained; a bunch of positive-parity levels shows up between 5.5 and 5.9 MeV, which might well be associated with the deduced M1 strength, since the E2 strength is negligible in this energy interval