The ${}^8$He($d,p$) reaction was studied in inverse kinematics at 15.4$A$ MeV using the MUST2 Si-CsI array in order to shed light on the level structure of ${}^9$He. The well known ${}^{16}$O($d,p$)${}^{17}$O reaction, performed here in reverse kinematics, was used as a test to validate the experimental methods. The ${}^9$He missing mass spectrum was deduced from the kinetic energies and emission angles of the recoiling protons. Several structures were observed above the neutron-emission threshold and the angular distributions were used to deduce the multipolarity of the transitions. This work confirms that the ground state of ${}^9$He is located very close to the neutron threshold of ${}^8$He and supports the occurrence of parity inversion in ${}^9$He.

• Received 29 April 2013

DOI:https://doi.org/10.1103/PhysRevC.88.034301