Cold Multinucleon Transfer and Synthesis of New Elements

Pairing correlations of nucleons and multi-nucleon transfer between heavy nuclei

“…This case can be realized in a weak coupling situation, where the probability for the individual step is much smaller than 0.5, and the multiple (enhanced) transfer is manifested in a particular exponential slope of the cross section for pair transfer as a function of pair number. Such cases have actually been observed [97,118,125] and some cases have been discussed in the previous section (see figures 22 and 23). Additional evidence will be presented in section 5.…”

“…Basic information on nucleon transfer between nuclei, in particular of single-and two-nucleon transfer between heavy ions, are discussed in detail in [3,26,72,157]. A survey of cold transfer reactions leading to large changes of mass asymmetry (up to fusion) has been published recently [125]. Actually we can define reactions which show distinct features of pairing in nuclei as cold reactions, and this will also be one of the guidelines in the present review.…”

“…For this representation an elaborate formula with parameters adjusted to known nuclear radii has to be used. We prefer the simpler definition of d 0 , which allows the comparison of a large body of data, see [123,125] and section 5.…”

“…Here we will discuss the enhancement within the semi-classical approach. Based on the experience with light projectiles an enhancement factor (EF), due to pairing for two-nucleon transfer between heavy nuclei, can be defined [118][119][120]125], which is particularly simple if the single-nucleon transfer probability P 1n is used as the appropriate measure: P 2n = EF (P 1n ) 2 . In the independent particle picture without correlations this factor would be just unity.…”

“…In this paper the enhancement of the pair transfer is predicted; in our definition of the JE this would correspond to the dc case, a direct current between two superfluid nuclear systems. In some related work by Gaudin [65] the enhanced transfer of nucleon pairs in the fission process is also discussed; indeed, the systematics of the odd-even effect in the transfer of protons is strongly related to the charge odd-even effect observed in the element yields of cold fission [33,69,125].…”