出版社：SISSA, Scuola Internazionale Superiore di Studi Avanzati
摘要：Much progress has been made in the study of the production and destruction mechanisms of 19F.
Recent model simulations indicate that the 19F(n, g)20F reaction could be the primary destruction
channel for fluorine during the thermal pulses of AGB stars, therefore an accurate determination
of the neutron capture cross section is of great importance. An activation measurement of the
neutron capture cross section of 19F has been performed at a stellar temperature of kT = 25 keV
using the Karlsruhe 3.7 MV Van de Graaff accelerator. The short half life of 20F (t1/2 = 11 s)
required the employment of the fast cyclic activation technique. A preliminary analysis indicates
a significantly lower neutron capture cross section at kT = 25 keV than is suggested in the current
literature. The new mesurement also greatly reduces the quoted uncerainty of 20%.
