${}^8$He nuclei stopped in nuclear track emulsion

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 $\hat{I}\pm$-spectrometry and to observe a thermal drift of ${}^8$He atoms in matter. Knowledge of the energy and emission angles of $\hat{I}\pm$-particles allows one to derive the energy distribution of $\hat{I}\pm$-decays Q${}_{2\hat{I}\pm }$. The presence of a "tail" of large values Q${}_{2\hat{I}\pm }$ is established. The physical reason for the appearance of this "tail" in the distribution Q${}_{2\hat{I}\pm }$ is not clear. Its shape could allow one to verify calculations of spatial structure of nucleon ensembles emerging as $\hat{I}\pm$-pairs of decays via the state ${}^8$Be${}_{2+}$.

9 pages, 4 figures, conference: The 22nd European Conference on Few Body Problems in Physics, Krakow, Poland, 9 - 13 September