Angular anisotropy of charged particles evaporated from deformed nuclei

Abstract

A semiclassical technique is developed for calculating the angular and energy distributions of charged particles evaporated from deformed nuclei. It includes an analytical expression for particle momentum at infinity via its momentum at the emission point, which reasonably reproduces exact calculations, and a triangular weighting function for averaging over the cascade temperature. Essential reduction in computational effort is achieved due to a compact expression for emission widths and a phenomenological treatment of penetration through an aspherical barrier. The application of this technique to alpha -emission from strongly excited Yb isotopes with aligned spin has produced values of the deformation parameter which are in good agreement with liquid drop model calculations.

α-nucleus potential for α-decay and sub-barrier fusion

“…Note that t(q, θ = 0 • , ℓ) > t(q, θ = 90 • , ℓ) in prolate nuclei. Therefore if we propose the independence of αcluster formation probability on the angle θ, then the α-particles should be emitted mainly at angle θ = 0 • (see also [23,25,30,31,32,33]). A similar effect is wellknown in the case of sub-barrier fusion reactions between spherical and deformed nuclei [34,37].…”

“…Therefore α-nucleus potential should depend on the angle θ between the direction of α-emission and the axial-symmetry axis of the deformed nucleus. Both the α-decay width and the transmission coefficient for tunnelling through the barrier are strongly dependent on θ [20,22,23,24,25,26,30,31,32,33]. This effect is considered in detail in microscopic models [23,24,25,26].…”

Dynamic and quasistatic trajectories in quasifission reactions and particle emission

“…The explicit expressions for R ν , ū, j 2 are summarized in the Appendix. They were obtained in the framework of the classical statistical model of particle emission from non-spherical nuclei [32,33,34]. As shown in Ref.…”

Alpha-particle emission as a probe of nuclear shapes and structure effects in proton evaporation spectra

“…The level scheme for S2Sr was constructed from a 3'-7 matrix obtained by requiring that at least one proton was detected and that k 7 exceeded 10. The matrix thus constructed was BAND: 2 3 4 (26) 2Z-l-----1 . .…”