Cross sections for 3H(7Li,n0)9Be and 3H(7Li,ntot).

Abstract

The $^{3}\mathrm{H}$${(}^{7}$Li,${\mathit{n}}_{0}$${)}^{9}$Be cross section was measured for 0.15${\mathit{E}}_{\mathrm{c}.\mathrm{m}.}$1.24 MeV at ${\mathrm{\ensuremath{\theta}}}_{\mathrm{lab}}$=0\ifmmode^\circ\else\textdegree\fi{}, 45\ifmmode^\circ\else\textdegree\fi{}, 90\ifmmode^\circ\else\textdegree\fi{}, and 135\ifmmode^\circ\else\textdegree\fi{} using Si(Li) diodes as neutron spectrometers. The $^{3}\mathrm{H}$${(}^{7}$Li,${\mathit{n}}_{\mathrm{tot}}$) cross section was measured for 0.05${\mathit{E}}_{\mathrm{c}.\mathrm{m}.}$1.5 MeV using a 4\ensuremath{\pi} neutron detector. The cross section for $^{3}\mathrm{H}$${(}^{7}$Li,${\mathit{n}}_{0}$${)}^{9}$Be was used to calculate the thermonuclear reaction rate for the temperature range 0.3--10 GK. The results support predictions that $^{9}\mathrm{Be}$ may be produced in quantities near spectroscopic limits of observation according to some models of inhomogeneous primordial nucleosynthesis.