Delayd fission rates for nuclei of
cosmochronological interest
studied at IRIS facility.
Nuclide | Half-life (s) | Q ( MeV ) | Radiation | Intens. (%) | Rate of del. fiss. |
226 Fr | 48 | 3.7 (1) | beta,gamma | - | - |
228 Fr | 39 | 4.2 | gamma 474 | 20 | < 2*10 {-7} |
230 Fr | 19 | - | gamma 129 | 100 | < 3*10 {-6} |
232 Fr | 5 (1) | - | gamma, beta, X | 100 | < 2*10 {-6} |
232 Ac | 35 | 3.4 (1) | gamma 665, X | 15 | < 10 {-6} |
233 Ra | 30 (5) | - | beta | 100 | - |
234 Ra | 30 (10) | - | beta | 100 | - |
234 Ac | 44 | 4.6 (15) | gamma 688+693 | 100 | < 10 {-4} |
References:
- "Search for delayed fission in neutron-rich nuclei",
Z.Phys. 337, 109 (1990).
- "The production of neutron-rich heavy nuclei of Astrophysical interest
at IRIS -facility",
Nucl.Instr.Meth. B70, 69 (1992).
- "Experimental approach to Nuclear Cosmochronology",
Proceedings of the 6-th Int. Conf. on Nuclei Far From Stability
and the 9-th Int. conf. on AMCO, held at Bernkastel-Kues, Germany,
p.875 (1992).