Production of proton-rich nuclei around Z = 84-90 in fusion-evaporation reactions

Abstract

Within the framework of the dinuclear system model, production cross sections of proton-rich nuclei with charged numbers of Z=84-90 are investigated systematically. Ta are analyzed thoroughly. The optimal excitation energies and evaporation channels are proposed to produce the proton-rich nuclei. The systems are feasible to be constructed in experiments. It is found that the neutron shell closure of N=126 is of importance during the evaporation of neutrons. The experimental excitation functions in the 40 Ar induced reactions can be nicely reproduced. The charged particle evaporation is comparable with neutrons in cooling the excited proton-rich nuclei, in particular for the channels with α and proton evaporation. The production cross section increases with the mass asymmetry of colliding systems because of the decrease of the inner fusion barrier. The channels with pure neutron evaporation depend on the isotopic targets. But it is different for the channels with charged particles and more sensitive to the odd-even effect. PACS number(s): 25.70. Jj, 25.60.Pj,

Rare Isotope Formation in Complete Fusion and Multinucleon Transfer Reactions in Collisions of 48Ca +248Cm around Coulomb Barrier Energies

“…In heavy-ion collisions, overcoming Coulomb barrier, kinetic energy of relative motion transforms rapidly into internal excitation of dinuclear system at contact point. The interaction potential distribution to distance, interaction time to impact parameter and internal excitation energy to reaction time for the systems of 48 Ca + 248 Cm reactions at incident energy E lab = 5.5 MeV/nucleon are shown in Fig. 1.…”

“…Only the particles at the states within the valence space are actively for nucleon transfer. The transition probability is related to the local excitation energy and nucleon transfer, which is microscopically derived from the interaction potential in valence space as described in [48,49].…”

“…For producing unknown superheavy elements, fusion-evaporation reactions have been widely used in different laboratories all over the world. In reactions of actinides with a double magic 48 Ca beam at Flerov Laboratory of Nuclear Reactions (FLNR, Dubna) [1,2], the synthesis of SHEs with atomic number Z up to 118 has been claimed. In Gesellschaft für Schwerionenforschung (GSI), the production of superheavy elements with Z = 107-112,114-117 has been identified [3,4].…”

“…In the three laboratories, FLNR [40], GSI [41] and RIKEN [42] obtain cross-section excitation functions of 3n, 4n evaporation channels for production of superheavy element Z=116 in 48 Ca induced reactions with 248 Cm targets, early or late, respectively. In the experiments of synthesizing superheavy nuclei (Z=116) with 48 Ca + 248 Cm [43][44][45][46][47], the massive independent yields of targetlike fragments have been observed, especially new heavy isotopes involved. Production cross section of all formed products brings us an opportunity to investigate the interplay between equilibrium and dissipation for low energy heavy-ion collisions as well as decay properties of excited SHN.…”

“…In this work, the 48 Ca induced complete and incomplete fusion reactions with the combination of 248 Cm are calculated with the DNS model. The aim of this paper is to study the dynamics on the sythesis cross sections of nuclides in complete and incomplete fusion of 248 Cm with 48 Ca projectile. The article is organized as follows: In Sec.…”