Possibility of on-line analysis of very short-lived nuclei with the aid of a spectrograph equipped with a laser ion source

The delay time of a few hundred ms for ions to diffuse out of most ion sources can be circumvented by ionising, with a laser beam, the atoms that have been deposited on a surface. For material deposited by a He-jet, nuclei with t 1 2 ≈ 0.1 s can be studied. Using a spectrograph equipped with such a laser ion source, we determined approximately the ionisation and transmission efficiencies. This was measured from the percentage of vaporised gold, as determined by a neutron activation method, transferred through the mass spectrograph. The overall efficiency was found to be greater than 10 −4.