William A. Fowler

Thermonuclear Reaction Rates, III

A revision and updating of charged particle reactions involving nuclei with A less than or approximately equal to 30, except for the

Relative Contributions of Uranium, Thorium, and Potassium to Heat Production in the Earth

sup 2

Tables of thermonuclear reaction rates for low-mass nuclei (1 ⩽ Z ⩽ 14)☆

H(d,

NUCLEOSYNTHESIS OF HEAVY ELEMENTS BY NEUTRON CAPTURE

gamma

Neutrino processes and pair formation in massive stars and supernovae.

)

Tables of thermonuclear-reaction-rate data for neutron-induced reactions on heavy nuclei☆

sup 4

Semiempirical thermonuclear reaction-rate data for intermediate-mass nuclei

He reaction whose reaction rate is very uncertain, is presented. Reactions involving neutrons are treated as neutron-producing reactions but factors for calculating the reverse reaction rate are provided for all reactions. The rates of the (n,

ON RELATIVISTIC ASTROPHYSICS

gamma

Neutron capture chains in heavy element synthesis

) reactions given previously have not been revised. The Maxwell-Boltzmann distribution is assumed to hold for the relative velocities of the interacting particles. (40 references) (BJG)

The Stability of Supermassive Stars

Data from a wide variety of igneous rock types show that the ratio of potassium to uranium is approximately 1 X 104. This suggests that the value of K/U ≈1 X 104 is characteristic of terrestrial materials and is distinct from the value of 8 X 104 found in chondrites. In a model earth with K/U ≈ 104, uranium and thorium are the dominant sources of radioactive heat at the present time. This will permit the average terrestrial concentrations of uranium and thorium to be 2 to 4.7 times higher than that observed in chondrites. The resulting models of the terrestrial heat production will be considerably different from those for chondritic heat production because of the longer half-life of U238 and Th238 compared with K40