Total cross section of the 3H(p,n)3He reaction from threshold to 4.5 MeV -: art. no. 015801

We report new measurements of the total cross section for the H-3(p,n)He-3 reaction from threshold (E-p = 1.02 MeV) to E-p=4.5 MeV. The experiment utilized specially prepared Ti-H-3 targets, and neutrons were detected using a 4 pi detector. A weak resonant structure due to an excited state in He-4 is observed which was not seen in previous cross section measurements. A new expression for the He-3(n,p)H-3 thermonuclear reaction rate for temperatures below 10 GK is presented which will allow for more accurate calculations of the yields of light elements produced by big-bang nucleosynthesis. [S0556-2813(99)03307-5].