New Candidates for Cluster Decay Experiments

Abstract

Heavy particle radioactivity was predicted in 1980. Starting in 1984 with C-14 radioactivity of Ra-223, the following cluster emitters have been experimentally identified up to now: Fr-221, Ra-221-224,Ra-226 Ac-225 Th-228,Th-230 Pa-231, U-230,U-232-236, Pu-236,Pu-238, and Cm-242. The detected new kinds of radioactivities are: C-14, O-20, Ne-22,Ne-24-26, Mg-28,Mg-30, and Si-32,Si-34. Only upper limits were determined for O-18 radioactivity of Th-226, Ne-24,Ne-26 emission from Th-232, F-23 radioactivity of Pa-231, Mg-28 emission from U-233,U-235, Ne-24,Ne-26 emission from U-234, Mg-30 emission from Np-237, Si-34 radioactivity of Pu-240 and of Am-241. The measured halflives are in good agreement with predicted values within analytical superasymmetric fission model. The strong shell effects observed in the present systematics was not fully exploited; new candidates for successful experiments are suggested.