Observation of Coulomb excitation of unstable nuclei utilization of a secondary beam

Abstract

An experimental technique to detect γ-rays from secondary-beam Coulomb excitation was developed. A secondary beam of 76Kr produced by the inverse reaction 9Be( 70Ge, 3n) was Coulomb excited by a 208Pb target. Weak γ-rays from the secondary-beam Coulomb excitation were discriminated from those of a primary beam by measuring triple coincidences of primary γ-rays, scattered particles and emitted γ-rays from the second target. Coulomb excitation of the unstable nucleus was observed for the first time in the medium heavy mass region. The observed yield of the 2 + → 0 + transition in 76Kr is consistent with that which is estimated from the known B(E2: 0 + → 2 +) for this nucleus.