Function `adas.r8giiiav`

def r8giiiav(u, gam2)

Evaluates the Maxwell averaged free-free Gaunt factor.

Parameters

u : float, array: h * c / ( lambda * 1.e-10 * te * e ), where h is the Planck constant (J s), c the speed of light (m/s), lambda wavelength in Angstrom, e the elementary charge (C) and te electron temperature (eV).
gam2 : float, array: iz**2 * IH / te, where IH is ionisation potential of hydrogen, te the electron temperature and iz is the charge state.

Returns

giiiav : float, array: free-free Gaunt factor (dimensionless)

Notes

IH=13.6eV for te in eV or 157894.0 for te in Kelvin.

Calls a fortran based shared object file - not pure python.

References

Evaluates equation 17 of: A. Burgess and H. P. Summers, 'Radiative Gaunt factors', Mon. Not. R. Astr. Soc., (1987) 226, 257-272

Version History

Martin O'Mullane, 22-09-2020
- First version

Example

For a wavelength of 3500A in a plasma with Zeff=2.5 at 450eV, the Maxwell averaged free-free Gaunt factor

>>> import adas as adas
>>> wave=3500.0
>>> te=450.0
>>> zeff=2.5
>>> energy = 6.6e-34 * 3e+08 / (wave * 1.0e-10 * 1.6e-19)
>>> gam2 = zeff**2 * 13.6 / te
>>> adas.r8giiiav(energy/te, gam2)
3.0266998400789156