The intermediate structure of fission resonances of 240Pu was observed with an experimental energy resolution of 7 keV in the excitation energy region of E* = 3.8-5.6 MeV using the 239Pu(d, pf)240Pu reaction. Two-vibrational resonance groups centered at E* = 4.6 MeV and 5.1 MeV, and attributed to the excitation of three and four β-phonons, were resolved into individual substates, which could be assigned to the low-spin members of Kπ = 0+ superdeformed (SD) rotational bands. In the region of the lower E* = 4.6 MeV resonance individual moments of inertia of six well separated bands could be extracted for the first time with values of Θ/ℏ2 around 157 MeV-1, close to that of the ground state band in the second well. From the level density of these Kπ = 0+ band heads the excitation energy of the SD ground state was determined to (2.25 ± 0.20) MeV, in agreement with earlier estimates from excitation functions.
|Number of pages||9|
|Journal||Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics|
|Publication status||Published - Apr 26 2001|
ASJC Scopus subject areas
- Nuclear and High Energy Physics