Two New Alpha-Particle Emitting Isotopes of Element 105, 261Ha and 262Ha
Abstract
Two new α-emitting isotopes of element 105 with mass numbers 261 and 262 have been discovered. The 8.93-MeV 1.8-sec 261Ha was produced by the reactions 250Cf(15N,4n)261Ha and 249Bk(16O,4n)261Ha, and the 8.45-MeV 40-sec 262Ha by the reaction 249Bk(18O,5n)262Ha. The isotopic assignments are based on both α-recoil milking and mother-daughter time-correlation measurements. An upper limit of 50% for branching by spontaneous fission was set for 261Ha. A so far unassigned 25-sec spontaneous-fission activity was observed in the bombardment of 249Bk with 18O ions.
- Publication:
-
Physical Review C
- Pub Date:
- November 1971
- DOI:
- 10.1103/PhysRevC.4.1850
- Bibcode:
- 1971PhRvC...4.1850G