Investigating the Borromean nucleus 29F at the neutron drip-line

Abstract

A nuclear halo is a nucleus which has a large extended surface region of either one or two pro-tons or neutrons surrounding a compact core nucleus. A Borromean nucleus is a special case consisting of a core surrounded by a two-nucleon halo. This creates a bound system where removing any one of these three major components causes it to break. [superscript 29]F is a Borromean nucleus, located at Z=9, N=20 on the map of nuclei. In neutron-rich nuclei such as this one, nuclear shell structure may change, and there is evidence to suggest that the magic number N=20 breaks down. Such breakdown has been observed in Mg and Na isotopes. This region is referred to as the N=20 island of inversion. [superscript 29]F is the most neutron-rich nucleus with N=20. It is therefore important to investigate if the N=20 shell gap breaks down at [superscript 29]F and whether this Borromean nucleus forms a 2s halo. To investigate [superscript 29]F, which has a half-life of only ~ 2.4ms, it has to be produced in a laboratory. To do this, a beam of a stable nucleus must collide with a target, creating many different fragments including [superscript 29]F. From this, [superscript 29]F needs to be identifed and separated from the other nuclei. Simulation results of how this will be done using the BigRIPS fragment separator and particle detectors at the RIKEN RI Beam Factory in Japan will be discussed in this thesis.