could be used because of the very small primordial yields of other light isotopes ( 6 Li, 9 Be, and 10,11 B). Recently, however, it became possible to detect 6 Li in metal-poor halo stars [2]. For the in [...] thus leading to the synthesis of heavier nuclei. One possible reaction sequence is 7 Li(n,γ) 8 Li(α,n) 11 B(n,γ) 12 B(β-,n) 12 C [5,6]. Subsequent neutron captures on 12 C and 13 C will then produce 14 C,