Eur. Phys. J. A (2016) 52: 32
https://doi.org/10.1140/epja/i2016-16032-3

Regular Article - Theoretical Physics

Alpha decay in electron environments of increasing density: From the bare nucleus to compressed matter

European Commission, Joint Research Centre, Institute for Transuranium Elements, Postfach 2340, D-76125, Karlsruhe, Germany

^* e-mail: fabio.belloni@ec.europa.eu

Received: 24 July 2015
Accepted: 13 January 2016
Published online: 22 February 2016

Abstract

The influence of the electron environment on the decay is elucidated. Within the frame of a simple model based on the generalized Thomas-Fermi theory of the atom, it is shown that the increase of the electron density around the parent nucleus drives a mechanism which shortens the lifetime. Numerical results are provided for ¹⁴⁴Nd , ¹⁵⁴Yb and ²¹⁰Po . Depending on the nuclide, fractional lifetime reduction relative to the bare nucleus is of the order of 0.1-1% in free ions, neutral atoms and ordinary matter, but may reach up to 10% at matter densities as high as 10⁴g/cm^3, in a high-Z matrix. The effect induced by means of state-of-the-art compression techniques, although much smaller than previously found, would however be measurable. The extent of the effect in ultra-high-density stellar environments might become significant and would deserve further investigation.