High-statistics measurement of the beta-delayed alpha spectrum of 20Na

TL;DR

This study provides a high-precision measurement of the beta-delayed alpha spectrum of 20Na, revising the decay scheme, discovering new low-intensity transitions, and offering an improved theoretical description through R-matrix analysis.

Contribution

It introduces a high-granularity measurement setup that refines the decay scheme and identifies previously unobserved low-energy alpha transitions in 20Na.

Findings

Discovery of three new low-energy alpha transitions.

Revised decay scheme of 20Na with updated transition data.

Improved decay modeling using R-matrix fit showing feeding to a broad 2+ state.

Abstract

A measurement of the 20Na beta-delayed alpha spectrum with a high-granularity set-up has allowed the decay scheme to be revised on several points. Three new transitions of low intensity are found at low alpha-particle energy. An R-matrix fit of the complete spectrum gives an improved description of the decay and indicates feeding to the broad 2^+ alpha-cluster state close to 9 MeV.