Question

The total power produced by the sun is 4x10^26W. Estimate the rate of solar neutrinos striking the earth, assuming that the sun’s power comes entirely from the p-p cycle.

Answer 1

The total power produced by the sun =4x10^26W

If the sun shines through hydrogen fusion, it ought to emit two neutrinos per fusion chain. The total flux of neutrinos from the sun ought to be 200 billion per second, corresponding to a flux of about 6.5 × 10^10 neutrinos per square centimeter per second hitting the earth.

Calculations

(Atoms made / second) = (He atoms / Joule) x (Joules / second) =0.25x10^12 x4x10^26 = 10^38
Two neutrinos are made for each He atom made, so 2x10^38 neutrinos are made each second.