出版社：SISSA, Scuola Internazionale Superiore di Studi Avanzati
摘要：The time of flight (TOF) method is an important tool for the experimental determination of neutron
capture cross sections which are needed for s-process nucleosynthesis in general, and for
analyses of branchings in the s-process reaction path in particular. So far, sample masses of at
least several milligrams are required to compensate limitations in the currently available neutron
fluxes. This constraint leads to unacceptable backgrounds for most of the relevant unstable branch
point nuclei, due to the decay activity of the sample. A possible solution has been proposed by
the NCAP project at the University of Frankfurt. A first step in this direction is reported here,
which aims at enhancing the sensitivity of the Karlsruhe TOF array by reducing the neutron flight
path to only a few centimeters. Though sample masses in the microgram regime can be used by
this approach, the increase in neutron flux has to be paid by a higher background from the prompt
flash related to neutron production. Test measurements with Au samples are reported.
