A precursor of β—delayed fission：^230Ac

1 INTRODUCTIONNuclei far from stability are characterized by a IUimer of new phenomena. hi heavyneutron-rich region, one of these is P-delayed fission (PDF), i.e., fission from an exitedstate in which the nucleus tu-rns out to be after P decay. For the first time the existenceof an P-delayed fission island was pointed out by Berlovich and Novikov in 1969.1]PDF provides the possibility of investigating nuclei far from stability, which is im-possible with ordinary techniques. For exam…

A precursor of β-delayed fission:230Ac

The 230Ra has been produced via multinucleon transfer and dissipativefragmentation of heavy target in the 60 MeV/u 18O ion reaction with natural thorium.The radium was radiochemically separated from irradiated thorium targets. 230Acwas obtained by 230Ra β-→ 230Ac. Thin Ra sources were prepared for observing fissionfragments from β-delayed fission of 230Ac. The sources were exposed to the micafission track detectors and measured by a HPGe γ detector. The two fission eventswere obtained and could been assigned to theβ-delayed fission of 230Ac. The β-delayedfission probability of 230Ac was determined to be (1.19+0.85) × 10-8.