Two-dimensional nuclear inertia : analytical relationships

The components of the nuclear inertia tensor, functions of the separation distance R and of the radius of the light fragment R2, BRR(R,R2), BRR2(R,R2), and BR2R2(R,R2) are calculated within the Werner-Wheeler approximation, by using the parametrization of two intersected symmetric or asymmetric spheres. Analytical relationships are derived. When projected to a path R2=R2(R), the reduced mass is obtained at the touching point. The two one-dimensional parametrizations with R2=const, and the volume V2=const previously studied, are found to be particular cases of the present more general approach. Illustrations for the cold fission, cluster radioactivity, and α decay of 252Cf are given

New island of cluster emitters

A new region of proton-rich parent nuclei decaying by spontaneous cluster emission with a measurable branching ratio relative to alpha decay is predicted within the analytical superasymmetric fission model. After a brief presentation of the model and of the seven mass tables used to calculate the released energy, the obtained results are discussed. Measurable half-lives and branching ratios are estimated for 12C, 16O, 28Si, and other cluster radioactivities of some nuclides having proton and neutron numbers in the range Z=56–64 and N=58–72. Such nuclei far from stability could be produced in reactions induced by radioactive beams

Potential energy surfaces for cluster emitting nuclei

Potential energy surfaces are calculated by using the most advanced asymmetric two-center shell model allowing to obtain shell and pairing corrections which are added to the Yukawa-plus-exponential model deformation energy. Shell effects are of crucial importance for experimental observation of spontaneous disintegration by heavy ion emission. Results for 222Ra, 232U, 236Pu and 242Cm illustrate the main ideas and show for the first time for a cluster emitter a potential barrier obtained by using the macroscopic-microscopic method.Comment: 10 pages, 21 figures, revtex

Neočekivana svojstva blizinskog potencijala

The cold fission barriers of heavy and superheavy nuclei (Z=80-120) are computed using two macroscopic models, the Yukawa-plus-exponential and the proximity potential. No shell and pairing corrections have been added. Unexpectedly, the barriers are showing two maxima in a wide region of nuclei (Z=96-120, mostly neutron-deficient ones) and various mass and charge asymmetries, lower for lighter nuclei and larger for heavier ones. The rather shallow minimum separating the maxima can reach a depth of 37 keV in the Yukawa-plus-exponential model and 190 keV in the proximity potential model.Fisijski bedemi teških i superteških jezgri (Z = 80 − 120) određeni su u dva makroskopska modela (Yukawa + eksponencijalni potencijal i blizinski potencijal) ne izračunavajući korekcije ljuske i sparivanje. U širokom području jezgri (Z = 96−120, uglavnom s manjkom neutrona), različitih masa i asimetrija naboja, bedemi imaju dva maksimuma, koji su niži za lakše jezgre a viši za teže jezgre. Plitki minimum izmedu maksimuma doseže dubinu 37 keV u Yukawa + eksponencijalnom modelu i 190 keV u modelu blizinskog potencijala

Neočekivana svojstva blizinskog potencijala

The cold fission barriers of heavy and superheavy nuclei (Z=80-120) are computed using two macroscopic models, the Yukawa-plus-exponential and the proximity potential. No shell and pairing corrections have been added. Unexpectedly, the barriers are showing two maxima in a wide region of nuclei (Z=96-120, mostly neutron-deficient ones) and various mass and charge asymmetries, lower for lighter nuclei and larger for heavier ones. The rather shallow minimum separating the maxima can reach a depth of 37 keV in the Yukawa-plus-exponential model and 190 keV in the proximity potential model.Fisijski bedemi teških i superteških jezgri (Z = 80 − 120) određeni su u dva makroskopska modela (Yukawa + eksponencijalni potencijal i blizinski potencijal) ne izračunavajući korekcije ljuske i sparivanje. U širokom području jezgri (Z = 96−120, uglavnom s manjkom neutrona), različitih masa i asimetrija naboja, bedemi imaju dva maksimuma, koji su niži za lakše jezgre a viši za teže jezgre. Plitki minimum izmedu maksimuma doseže dubinu 37 keV u Yukawa + eksponencijalnom modelu i 190 keV u modelu blizinskog potencijala