Isotope Distributions in the Reaction ofU238withU

Prospects of heavy and superheavy element production via inelastic nucleus-nucleus collisions – from238U+238U to18O+254Es

“…These reactions were already proposed between the mid-60s and mid-70s [10,11]. However, it was only after 238 U beams with sufficiently high energy and intensity became available at the Gesellschaft für Schwerionenforschung (GSI), Darmstadt, that the entire range of multi-nucleon transfer or deep-inelastic reactions up to 238 U on 238 U and 248 Cm were explored [12,13]. These reactions, their results on the synthesis of heavy actinide isotopes, the understanding of the processes leading to these products and the potential for the synthesis of new, neutron-rich isotopes will be discussed in this article.…”

“…These reactions, their results on the synthesis of heavy actinide isotopes, the understanding of the processes leading to these products and the potential for the synthesis of new, neutron-rich isotopes will be discussed in this article. To a large extent it includes information available in [12][13][14] and, more recently, summarized and expanded in [15].…”

“…This means that in the symmetric and binary 92 U + 92 U reaction also element 114 primary fragments are synthesized with the same high cross section of 0.1 mb [12,15]. As the search for SHE, however, remained unsuccessful [18], it became especially interesting to investigate and better understand the synthesis of highly fissile actinide products formed in multi-nucleon transfer reactions.…”

“…To obtain deeper and more quantitative insights into the reaction mechanism leading to surviving heavy actinides and to SHE, calculations were performed to reproduce measured isotope distributions of 98 Cf, 99 Es and 100 Fm in the reaction of ≤7.5 MeV/u 238 U on 38 U; for details see [12,15]. These calculations started with measured isotope distributions of the complementary light elements 86 Rn, 85 At and 84 Po, assuming that these distributions were not strongly altered by prompt fission.…”

Actinide Production in the Reaction of Heavy Ions withCurium-248

“…A s t h e collision becomes more central, t h e interaction time increases, t h e thermalization of energy and angular momentum a n d t h e equilibration of N/Z becomes more complete, followed by t h e partial relaxation of the mass difference. This results in product mass distributions peaked around t h e e n t r a n c e channel mass a n d c h a r g e values [Tho79,Bin77,Kra76,Kra74,0tt76,Sch78). At t h e fully damped extreme lies t h e completely equilibrated system, which can bc thought, nf a s a quasi-compound nucleus.…”