Speaker
Dr
Adrien Matta
(University Of Surrey)
Description
The "Island of Inversion" refers to a group of very neutron rich nuclei centred on $^{30}$Ne and $^{32}$Mg, in which the gap in energy at N=20 between the $1s0d$ and $0f1p$ shells has become sufficiently small to allow the latter configurations to dominate the ground states, effectively favouring particle-hole configurations. One of the keys to understanding the "Island of Inversion" lies in the evolution of the orbital energies as we move from stable nuclei into this region.
The $^{28}$Mg($d$,$p$)$^{29}$Mg reaction offers detailed probing of the neutron orbitals and interactions that determine the properties of the more neutron-rich isotopes where the "Island of Inversion" becomes fully developed. The details that are hidden in the properties of $^{32,34}$Mg are exposed and quantified in the structure of $^{29}$Mg.
The changes in the relative energies of shell model orbits, depending on the neutron/proton balance in the nucleus, cause level energies to evolve and therefore change the shell gaps and their corresponding magic numbers, effectively replacing N=20 by N=16. This can be studied most effectively by means of single nucleon transfer reactions.
The ($d$,$p$) reaction is an ideal tool to probe this behaviour, as it allows the transfer of a neutron into the $0d3/2$, $0f7/2$, $1p3/2$ and higher lying orbitals, and the energies of the observed states relate directly to the spacing between the $sd$ and $fp$ orbitals at $N$=20.
We will present results obtained recently at TRIUMF in inverse kinematic, using a $^{28}$Mg beam produced and reaccelerated by the ISAC-II facility. The $^{29}$Mg spectroscopy was studied via the missing mass method and particle-gamma coincidences obtained from the combination of SHARC and TIGRESS arrays.
Recently obtained results on $^{29}$Mg spectroscopy studied via ($d$,$p$) using the SHARC and TIGRESS arrays will be presented. The $^{28}$Mg($d$,$p$)$^{29}$Mg reaction offers detailed probing of the neutron orbitals and interactions that determine the properties of the more neutron-rich isotopes where the "Island of Inversion" becomes fully developed. The details that are hidden in the properties of $^{32,34}$Mg are exposed and quantified in the structure of $^{29}$Mg.
Primary authors
Dr
Adrien Matta
(University Of Surrey)
Dr
Nigel Orr
(LPC Caen)
Prof.
Wilton Catford
(University of Surrey)
Co-authors
Dr
Adam Garnsworthy
(TRIUMF)
Dr
Christian Diget
(University of York)
Dr
Christopher Pearson
(TRIUMF)
Dr
Franck Delaunay
(LPC Caen)
Dr
Gavin Lotay
(University Of Surrey)
Dr
Greg Hackman
(TRIUMF)
Dr
Jack Henderson
(TRIUMF)
Dr
Jenna Smith
(TRIUMF)
Mr
Knapton Andrew
(University Of Surrey)
Dr
Mohamad Moukaddam
(TRIUMF)
Dr
Panu Ruotsalainen
(TRIUMF)
Mr
Ryan Wilkinson
(University Of Surrey)
Mr
Sam Hallam
(University of Surrey - TRIUMF)
Mr
Steffen Cruz
(UBC & TRIUMF)
