Vibrational resonances below 5 MeV in the fission of 240Pu

Abstract Using the 239 Pu(d, pf) reaction, the next lower K π = 0 + vibrational resonance below 5 MeV in the deformed potential of 240 Pu was located at 4.55 MeV. The resultant spacing of fission vibrations near 5 MeV in the second minimum is 500 keV. A resonance at 4.70 MeV is interpreted as the K π = 0 − vibration coupled to the 4.55 MeV K π = 0 + state, which yields E ( K π = 0 − ) = 150 keV relative to the ground state of the second minimum.