$\beta$β-delayed particle emission from 21Mg

The \(\beta\)-delayed particle emission from 21Mg was studied at the Radioactive Ion Beam Line in Lanzhou (RIBLL1). Silicon array and high-purity germanium (HPGe) detectors were used to detect the charged particles and \(\gamma\)-rays emitted from the decay. Half-life time of 21Mg was determined to be 121.9(6) ms. New levels (5.639(26) MeV and 6.644(34) MeV) in the nucleus 21Na were observed. An improved proton spectrum coincident with \(\gamma\)-rays at 1.633 MeV was obtained. A new partial decay scheme was constructed based on the present measurement.