Neutronless -accompanied ternary fission of

Abstract

: A new type of decay corresponding to the neutronless 10 Beaccompanied fragmentation of 252 Cf is studied. We employ a cluster model similar to the model used for the description of cluster radioactivity. No preformation factors were considered. The ternary relative isotopic yields were calculated as the ratio of the penetrability of a given ternary fragmentation over the sum of penetrabilities of all possible ternary neutronless fragmentations. The corresponding barriers between the light and heavy fragment and between the 10 Be cluster and the two heavier fragments were computed with the help of a double folding potential generated by M3Y-NN effective interaction and realistic fragment ground state deformations. Also, we studied the influence of the fragment excitation energies on the yields, by including the level densities and the β-stretching of the fragments. The new phenomenon could be experimentally observed by the triple gamma coincidence technique between the fragments and 10 Be.PACS number : 25.85.Ca,27.90.+b

Ternary-fission mass distribution ofCf252: A level-density approach

“…Rubchenya et al [6] employed a new dynamic model by assuming that light particles are formed as a result of two random neck ruptures. Sǎndulescu et al [7,8], with the help of a coplanar three-body cluster model, investigated ternary fission by calculating the relative isotopic yield and by finding the existence of long-life tri-nuclear molecules. Poenaru et al calculated [9] the complete energy systematics of the ternary fission of nuclides with Z = 90-116 for various third fragments.…”

α decay as a probe of nuclear incompressibility

“…v D and v ex are the direct and exchange parts of the effective NN interaction. Fortunately, the barrier between the fragments in this model could be calculated quite accurately where the touching configurations are situated inside the barriers and the shapes of the fragments are constant at every stage of the decay [51]. The density-dependent M3Y interaction based on the G-matrix elements of the Reid NN potential has the form [50,52] v(s,…”

“…A slight modification to this density-dependent form will be introduced to account for the expected shallow pocket in the α-daughter potential. The existence of the shallow pocket in the ion-ion potential is related to such evidence as the resonant structures in the collisions of light [57] and heavy [58,59] nuclei, cluster radioactivity [60], and binary and ternary cold fragmentations of heavy nuclei [51]. Furthermore, the existence of pockets in the entrance channel potentials is crucial for the fusion reactions [61][62][63] and the observed fusion windows for superheavy elements synthesis [64,65].…”

“…In a recent work [6], a potential with a thick barrier and shallow pocket, produced with M3Y-Reid effective NN forces supplemented with a repulsive core, is used to explain the steep falloff of fusion cross sections at energies far below the Coulomb barrier. For α decay, and other tunneling reactions, the thickness of the barrier is very crucial because it affects the penetrability, and the existence of the repulsive core prevents the reabsorption of the outgoing particle by the daughter nucleus [51]. The reduction in the nuclear potential caused by using the density dependence of the effective interaction is not enough in cases when it produces deeper pockets and thinner barriers, below a certain energy, than required [6].…”

Quantum Mechanical Fragmentation Theory for Cold Distribution of Masses and Charges in Fissipning Nuclei and Nuclei Formed in Heavy Ion Reactions

“…[16]. More recently, an a-particle-and heavy cluster-(like 10 jBe, U C and 33 > 34 > 35 gi) accompanied ternary cold fission is also observed [17][18][19][20], which is treated as binary cluster decay of the daughter nucleus [21,22]. Interesting enough, the QMFT had predicted the fission phenomenon to be a cold pro cess, as early as in 1974/75, and prior to experiments.…”