Jim Fuller edited subsection_Joule_Damping_A_gravity__.tex  about 9 years ago

Commit id: 77408473bedd1f707a35cec3c0e6e6794a72c362

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where $\eta$ is the magnetic diffusivity.  The joule damping rate of equation \ref{joule} can be compared with the damping rate from radiative diffusion, $\Gamma_r = k_r^2 \kappa$, where $\kappa$ is the thermal diffusivity. The ratio of joule damping to thermal damping is  \begin{equation} \begin{align}  \label{eqn:jouleratio}  \frac{\Gamma_B}{\Gamma_r} = &=  \frac{\eta}{\kappa} \frac{B^2 k_r^2}{(4 \pi)^2 \rho \omega^2} \nonumber \\ = &=  \frac{\eta}{\kappa} \frac{l(l+1) B^2 N^2}{(4 \pi)^2 \rho r^2 \omega^4} \, . \end{equation} \end{align}