spectral_density_lite
- plasmapy.diagnostics.thomson.spectral_density_lite(wavelengths, probe_wavelength: float, n: float, T_e: ndarray, T_i: ndarray, efract: ndarray, ifract: ndarray, ion_z: ndarray, ion_mass: ndarray, electron_vel: ndarray, ion_vel: ndarray, probe_vec: ndarray, scatter_vec: ndarray, instr_func_arr: ndarray | None = None, notch: ndarray | None = None) tuple[floating | ndarray, ndarray] [source]
The lite-function version of
spectral_density
. Performs the same thermal speed calculations asspectral_density
, but is intended for computational use and thus has data conditioning safeguards removed.- Parameters:
wavelengths ((Nλ,)
ndarray
) – The wavelengths in meters over which the spectral density function will be calculated.probe_wavelength (real number) – Wavelength of the probe laser in meters.
n (
ndarray
) – Total combined number density of all electron populations in m^{-3}.T_e ((Ne,)
ndarray
) – Temperature of each electron population in kelvin, where Ne is the number of electron populations.T_i ((Ni,)
ndarray
) – Temperature of each ion population in kelvin, where Ni is the number of ion populations.efract ((Ne,)
ndarray
) – Anndarray
where each element represents the fraction (or ratio) of the electron population number density to the total electron number density. Must sum to 1.0. Default is a single electron population.ifract ((Ni,)
ndarray
) – Anndarray
object where each element represents the fraction (or ratio) of the ion population number density to the total ion number density. Must sum to 1.0. Default is a single ion species.ion_z ((Ni,)
ndarray
) – Anndarray
of the charge number \(Z\) of each ion species.ion_mass ((Ni,)
ndarray
) – Anndarray
of the mass number of each ion species in kg.electron_vel ((Ne, 3)
ndarray
) – Velocity of each electron population in the rest frame (in m/s). If set, overrideselectron_vdir
andelectron_speed
. Defaults to a stationary plasma[0, 0, 0]
m/s.ion_vel ((Ni, 3)
ndarray
) – Velocity vectors for each electron population in the rest frame (in m/s). If set, overridesion_vdir
andion_speed
. Defaults to zero drift for all specified ion species.probe_vec ((3,) float
ndarray
) – Unit vector in the direction of the probe laser. Defaults to[1, 0, 0]
.scatter_vec ((3,) float
ndarray
) – Unit vector pointing from the scattering volume to the detector. Defaults to [0, 1, 0] which, along with the defaultprobe_vec
, corresponds to a 90 degree scattering angle geometry.instr_func_arr (
ndarray
, shape (Nwavelengths,) optional) –The instrument function evaluated at a linearly spaced range of wavelengths ranging from \(-W\) to \(W\), where
\[W = 0.5*(\max{λ} - \min{λ})\]Here \(λ\) is the
wavelengths
array. This array will be convolved with the spectral density function before it is returned.notch ((2,) or (N, 2)
ndarray
, keyword-only, optional) – A pair of wavelengths in meters which are the endpoints of a notch over which the output Skw is set to 0. Can also be input as a 2D array which contains many such pairs if multiple notches are needed. Defaults to no notch.
- Returns:
alpha (float) – Mean scattering parameter, where
alpha
> 1 corresponds to collective scattering andalpha
< 1 indicates non-collective scattering. The scattering parameter is calculated based on the total plasma density \(n\).Skw (
ndarray
) – Computed spectral density function over the inputwavelengths
array with units of s/rad.