Question

A maths question in nuclear physics....

Answer 1

The thermonuclear rate at which protons are destroyed by the
proton-proton reaction at stellar temperatures is given approximately
by\[R_pp = 1.1x10^{15}\rho^2X^2T^{-2/3}\exp^{-3381(T^{-1/3})} m^{-3}s^{-1}\]where \rho is the density of stellar material and X is the mass fraction
of hydrogen. Estimate the lifetime (in years) of protons against
the proton-proton reaction in material where T = 1.5 × 10^7 K, rho =
105 kgm−3 and X = 0.5. Comment on your result.