$^8$He nuclei stopped in nuclear track emulsion

TL;DR

This study investigates the decay properties of stopped $^{8}$He nuclei in nuclear track emulsion, revealing a tail in the alpha-decay energy distribution that may shed light on nuclear structure and decay mechanisms.

Contribution

It provides experimental data on $^{8}$He decay in emulsion, including alpha-spectrometry and the observation of a tail in the alpha-decay energy distribution, which is not yet fully understood.

Findings

Detection of a 'tail' in the alpha-decay energy distribution Q$_{2 ext{α}}$

Observation of thermal drift of $^{8}$He atoms in matter

Potential to verify nuclear structure models through decay analysis

Abstract

The fragment separator ACCULINNA in the G. N. Flerov Laboratory of Nuclear Reactions of JINR was used to expose a nuclear track emulsion to a beam of radioactive $^{8}$He nuclei of energy of 60 MeV and enrichment of about 80%. Measurements of decays of $^{8}$He nuclei stopped in the emulsion allow one to evaluate possibilities of $\alpha$-spectrometry and to observe a thermal drift of $^{8}$He atoms in matter. Knowledge of the energy and emission angles of $\alpha$-particles allows one to derive the energy distribution of $\alpha$-decays Q$_{2\alpha}$. The presence of a "tail" of large values Q$_{2\alpha}$ is established. The physical reason for the appearance of this "tail" in the distribution Q$_{2\alpha}$ is not clear. Its shape could allow one to verify calculations of spatial structure of nucleon ensembles emerging as $\alpha$-pairs of decays via the state $^8$Be$_{2+}$.