Derived Parameter: Electron-Neutral Collision Frequency

Electron-Neutral Collision Frequency

The electron-neutral collision frequency, case A from De Pontieu et al. (2001) following Osterbrock's treatment.

$\nu_{eH}=\nu_{ei} +\nu_{en}$

where

$\nu_{ei}=3.759\times10^{-6}n_eT^{-3/2}\ln{\Lambda}$
$\nu_{en}=5.2\times10^{-11}\nu_{ei}\frac{n_n}{n_e}\frac{T^2}{\ln{\Lambda}}$
$\ln \Lambda=23.5 - \ln \left (1.2046 \times 10^5 \frac{\sqrt{n_e} }{T^{1.25}} \right ) - \sqrt{10^{-5} + \frac{\left ( \ln(T) - 11.35926 \right )^2}{16}$

where n_n is the number density of neutrals.

eH collision frequency values for quiet Sun (model 1001; blue), facula (1005; red), and umbra (1006; green).

Model 1001 Values (quiet Sun)

Model 1005 Values (facula)

Model 1006 Values (umbra)

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