The observation of 84Mo

Abstract The 28 Si( 58 Ni, 2n) 84 Mo reaction has been studied at 195 MeV bombarding energy. The prompt gamma rays were detected in an array of twenty, escape-suppressed Ge detectors in coincidence with the recoiling nuclei, which were identified by A and Z with a recoil separator. A 443.8±0.3 keV gamma ray was observed from 84 Mo which is interpreted as the 2 + −0 + transition in this nucleus. This would indicate a quadrupole deformation e 2 ∼0.30. This result confirms that 76 Sr lie at the centre of the region of deformed nuclei with A ∼80.