There is always a generic value on the development of understanding about SHEs,
in particular when “new” elements are discovered, because these provide a
fertile ground for testing the borderlines of nuclear existence.
In fact, these elements exhibit an atomic nucleus with so many protons that they
“classically” would not exist at all, due to strong Coulomb repulsion forces
between the protons. However, nuclear shell models do not predict only the SHEs
that we can produce in nuclear fusion-evaporation reactions but also a fabled “island” of nuclear
stability of SHEs at extremely large proton and neutron numbers (north east of the
nuclear map), which is out of reach of current SHE production technologies.
Those elements we know are short-lived and vanish within seconds of their production. If,
however, neutron-rich SHEs from this island can exist and are being produced in
the universe by, e.g., the rapid neutron capture (r-) process, their evidence may
be present in spectra of potential astrophysical sites, like in neutron star mergers.
But then, how to detect them if not by telltale photons from such distant sources,
because they are not primordial?
Hence, established spectral lines from pioneering spectroscopy experiments may serve like fingerprints for multi-messenger
astronomy searching for SHEs from r-process events, which may push
the limits of nuclear stability far beyond the nowadays-achievable.
Moreover, the experimental exploration of atomic emission spectra is essential to
advance our understanding of the atom’s structure.
This is because relativistic, many-body, and quantum-electrodynamic effects become
increasingly important with proton number.
The investigations are also driven by the need for mapping single particle
and collective properties of atomic nuclei, which owe their existence to nuclear
shell effects, in a region of the map where very little or no nuclear spectroscopic
information is known. Given the atomic physics is well understood, measurements of
hyperfine structure and isotope shifts of spectral lines will enable these nuclear
properties (such as spins and moments) to be extracted independent of nuclear model
assumptions and thus will help to improve predictions for next spherical
nuclear-shell closures around the “island of stability”.