A search for the heaviest isotopes of fluorine, neon, and sodium was conducted by fragmentation of an intense Ca48 beam at 345 MeV/nucleon with a 20-mm-thick beryllium target and identification of isotopes in the large-acceptance separator BigRIPS at the RIKEN Radioactive Isotope Beam Factory. No events were observed for F32,33, Ne35,36, and Na38 and only one event for Na39 after extensive running. Comparison with predicted yields excludes the existence of bound states of these unobserved isotopes with high confidence levels. The present work indicates that F31 and Ne34 are the heaviest bound isotopes of fluorine and neon, respectively. The neutron dripline has thus been experimentally confirmed up to neon for the first time since O24 was confirmed to be the dripline nucleus nearly 20 years ago. These data provide new keys to understanding the nuclear stability at extremely neutron-rich conditions.
ASJC Scopus subject areas
- Physics and Astronomy(all)