ALUMINUM-26, BE-10, AND CL-36 DEPTH PROFILES IN THE CANYON-DIABLO IRON METEORITE

We have measured activities of the long-lived cosmogenic radionuclides Al-26, Be-10, and Cl-36 in 12 fragments of the iron meteorite Canyon Diablo and have constructed production rate-versus-depth profiles of t hose radionuclides. Profiles determined using differential particle fl uxes calculated with the LAHET code system are in good agreement with Al-26, Be-1O, and Cl-36 experimental data, but the agreement for Cl-36 was obtained only after neutron-induced cross sections were modified. Profiles calculated with lunar particle fluxes are much lower than ex perimental Canyon Diablo profiles. The cosmic ray exposure ages of mos t samples are near 540 m.y.