DataSet D108069

\[\mathrm{e}^- + \mathrm{H} \; n=2 \rightarrow \mathrm{H} \; n=3 + \mathrm{e}^-\]


Process EEX: Excitation
Data type cross section | uploaded on 2023-02-08
Comment Fit function and data were taken from Janev et al. p22. Errors: E<30eV -> 40%, 30eV<E<80eV -> 20%, E>80eV -> 10%.

Methodsemi-empirical
Columns
  1. E /eV
  2. sigma /cm2
Threshold1.889 eV
Ref
DataDownload (data from fit)

Fitted Data

Fit Function
Details
\[\sigma_{ex}^{n=1 \rightarrow 3,4,5} = \frac{5.984 \times 10^{-16}}{I X} \Bigg[ \frac{E - I}{E}\Bigg]^{A_6} \Bigg[ \sum_{j=1}^4 \frac{A_j}{X^{j-1}} + A_5\ln X \Bigg], X = \frac{E}{I}\]
Python
def h_eex_janev_15(E, A1, A2, A3, A4, A5, A6, I):
    """
    This function calculates electron impact excitation cross sections (in cm2) of 
    H n=1 to n=3, 4, 5 and n=2 to n=3
    param E: requested electron-impact energy in eV
    type E: float, np.ndarray
    param Ai: fit coefficient 
    type Ai: float
    param I: threshold energy in eV
    type I: float
    """
sigma =  5.984e-16/E*((E-I)/E)**A6*(A1/(E/I)**0+A2/(E/I)**1+A3/(E/I)**2 +
                                         A4/(E/I)**3+A5*np.log(E/I))
return sigma
Fit Precision2.4 %
Fit Coefficients
A1
 5.237e+00
A2
 1.192e+02
A3
-5.954e+02
A4
 8.167e+02
A5
 3.891e+01
A6
 1.320e+00
I
 1.889e+00
x-range 1.889 –