HALF-LIFE OF THE ELECTRON-CAPTURE DECAYING ISOTOPE AM-236

The neutron deficient americium isotope Am-236 has been produced via t he U-235(Li-6, 5n) reaction. The reaction products were transported to an ion source of the on-line isotope separator (JAERI-ISOL) by a He/K Cl aerosol jet transport system, and americium atoms were successfully ionized and mass-separated. PuK x rays associated with the EC decay o f Am nuclei at the mass fraction of 236 were observed, indicating the definite identification of Am-236. The half-life of Am-236 is determin ed to be 4.4+/-0.8 min and the production cross section is estimated t o be about 70 mu b.