Superallowed α Decay to Doubly Magic Sn100

Abstract

We report the first observation of the 108 Xe → 104 Te → 100 Sn α-decay chain. The α emitters, 108 Xe [Eα = 4.4(2) MeV, T1 /2 = 58 +106 −23 µs] and 104 Te [Eα = 4.9(2) MeV, T1 /2 <18 ns], decaying into doubly magic 100 Sn were produced using a fusion-evaporation reaction 54 Fe(58 Ni,4n) 108 Xe, and identified with a recoil mass separator and an implantation-decay correlation technique. This is the first time α radioactivity has been observed to a heavy self-conjugate nucleus. A previous benchmark for study of this fundamental decay mode has been the decay of 212 Po into doubly magic 208 Pb. Enhanced proton-neutron interactions in the N = Z parent nuclei may result in superallowed α decays with reduced α-decay widths significantly greater than that for 212 Po. From the decay chain, we deduce that the α-reduced width for 108 Xe or 104 Te is more than a factor of 5 larger than that for 212 Po.

α-Cluster structure above double-shell closures and α-decay of 104Te

“…By varying only the parameter R, it is verified that the energy range 5. 13 MeV < E(0 + ) < 5.3 MeV provides T 1/2,α values compatible with the experimental measure, and simultaneously, is compatible with the experimental measure of Q α . The production of such results with P α = 1 corroborates the indication of the superallowed α-decay of 104 Te by Auranen et al [13].…”

“…13 MeV < E(0 + ) < 5.3 MeV provides T 1/2,α values compatible with the experimental measure, and simultaneously, is compatible with the experimental measure of Q α . The production of such results with P α = 1 corroborates the indication of the superallowed α-decay of 104 Te by Auranen et al [13]. In addition, it should be noted that the correspondence with the experimental data is obtained with an α + core potential which showed to be successful in nuclei of other mass regions with the same fixed parameters and without L-dependent parameters.…”

“…The ratios γ 2 α ( 104 Te)/γ 2 α ( 212 Po) indicate a much higher degree of α-clustering for 104 Te than for 212 Po. Auranen et al [13] make a similar comparison of 104 Te and 212 Po using the definition of reduced α-decay width (identified as δ 2 ) from Ref. [25].…”

Resonant and scattering states in the α+α system from the nonlocalized cluster model

“…A combination of our formalism with an imaginary optical potential may also allow microscopic studies of these processes [85]. Extending the analysis to the up-right corner of the nuclide chart could be another working direction, where the medium-mass and heavy nuclei such as 104 Te and 212 Po are known to have rich cluster structures [86][87][88][89][90]. Recently, inspired by the non-localized cluster model, the quartetting wave function approach and the quartet model [91][92][93][94][95][96][97] are proposed to study α clustering in heavy nuclei such as 212 Po.…”

Post-formation in alpha emission from nuclei

“…The isotopic dependence on the cross sections reflects the predicted isotopic dependence of the number of alpha particles in tin isotopes [4,6]. The extreme case of this phenomenon appears at the doubly magic self-conjugate tin nucleus 100 Sn as a super-allowed α decay [7].…”