| Process | EEX: Excitation |
| Data type | cross section | uploaded on 2023-02-08 |
| Comment | Fit function and data were taken from Janev et al. p6. Error: E< 100 eV -> 15%, E>= 100 eV -> 10%. |
| Method | experimental |
| Columns |
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| Threshold | 10.200 eV |
| Ref |
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| Data | Download (data from fit) |
| Fit Function Details |
\[\sigma_{ex}^{n=1 \rightarrow 2} =\begin{cases} \frac{5.984 \times 10^{-16}}{IX} \Bigg[ \sum_{j=1}^5 \frac{A_j}{X^{j-1}} + A_6 \ln X\Bigg]; X=\frac{E}{I}; \; (E > 12.23) \\ A_7; \; (E > 11.56, E < 12.23) \\ 10^{-16} \big[A_8 + A_9(E - I) \big]; \; (E < 11.56). \end{cases}\] | ||||||||||||||||||||
| Python | def h_eex_janev_12(E, A1, A2, A3, A4, A5, A6, A7, A8, A9, I):
"""
This function calculates electron impact excitation cross sections (in cm2) of
H n=1 to n=2
param E: requested electron-impact energy in eV
type E: np.ndarray
param Ai: fit coefficient
type Ai: float
param I: threshold energy in eV
type I: float
"""
sigma = (5.984e-16/E)*(A1/(E/I)**0 + A2/(E/I)**1 + A3/(E/I)**2 +
A4/(E/I)**3 + A5/(E/I)**4 + A6*np.log(E/I))
ind_below = np.where(E < 12.23)
for ind in ind_below[0]:
if E[ind] < 11.56:
sigma[ind] = 1e-16*(A8 + A9*(E[ind]-I))
else:
sigma[ind] = A7
return sigma |
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| Fit Precision | 1.3 % | ||||||||||||||||||||
| Fit Coefficients |
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| x-range | 10.2 – |