The fluctuation-dissipation theorem is used to evaluate the screening factor of nuclear reactions due to the electromagnetic fluctuations in a plasma. We show that the commonly used Saltpeter factor is obtained if only fluctuations near the plasma eigenfrequency are assumed to be important (\omega \sim \omega_{ pe}\ll T (\hbar=k_{ B}=1)). By taking into account all the fluctuations, the highly damped ones, with \omega >\omega_{ pe}, as well as those with \omega\leq\omega_{ pe}, we find that nuclear reaction rates are higher than those obtained using the Saltpeter factor, for many interesting plasmas.
Categories: astro-ph physics.plasm-ph
