26Al MEASUREMENT WITH A CYCLOTRON.

The ALICE accelerator was used to count directly small quantities ( similar 5 multiplied by 10**9 atoms) of the isotope **2**6Al (half-life equals 7. 3 multiplied by 10**5 years). The possible use of this measurement of this nuclide. in marine sediments as an absolute dating technique in conjunction with similar measurements of **1**0Be (half life equals 1. 5 multiplied by 10**6 years) is discussed. The method used here to avoid interference form the isobar **2**6Mg is applicable to a number of other isobars of interesting long lived nuclides, thus expanding the potential application of the accelerator technique.