Carbon-Burning Nucleosynthesis at Constant Temperature

Synthesis of elements during thermonuclear burning of carbon is examined at a series of temperatures (T9 = 0.6, 0.8, 1.0, 1.2, and 1.4) and for several initial compositions. Recent experimental results for the (`2C + `2C)-reaction are used. A general method for numerical solution of nuclear-reaction networks is described. At the higher temperatures in the range now thought to to be appropriate for carbon burning in stars, T9 > 1, the Na/Mg ratio is similar to that of the Sun. At all temperatures considerable produc- tion of 20Ne occurs. By using the results of the reaction-network calculations, a simple analytic expression for energy generation during carbon burning is constructed. Neutron exposures during carbon burning are presented for investigation of the s-process