CollisionDB: DataSet D108175

${He}^{2 +} + H n = 5 \to {He}^{2 +} + H^{+} + e^{-}$

Process	HIN: Ionization
Data type	cross section \| uploaded on 2023-02-08
Comment	Fit function taken from p112. Error: E< 10/n^2keV/u -> 100%, 10/n^2 keV/u<E< 100/n^2keV/u -> 40%, 100/n^2 keV/u<E<1000/n^2 keV/u -> 30%, E<1000/n^2 keV/u -> 20%

Method	semi-empirical
Frame	Target
Columns	E /eV u^-1 sigma /cm²
Ref	B37: R. K. Janev, J. J. Smith, "Cross sections for collision processes of hydrogen atoms with electrons, protons, and multiply charged ions", IAEA- Atomic and Plasma–Material Interaction Data for Fusion, Vienna 4 (1993). [https://www.iaea.org/publications/1839/atomic-and-plasma-material-interaction-data-for-fusion]
Data	Download (data from fit)

Fitted Data

Fit Function
Details

σ_{i o n}^{1, 2, 3} (E) = (\frac{A_{9}}{3})^{4} 10^{- 16} A_{1} [\frac{e^{- \frac{A_{2}}{E_{n}}} \ln (1 + A_{3} E_{n})}{E_{n}} + \frac{A_{4} e^{- A_{5} E_{n}}}{E_{n}^{A_{6}} + A_{7} E_{n}^{A_{8}}}]; E_{n} = (\frac{3}{n})^{2} E

Python

def h_hin_javen_he_scaled(E, A1, A2, A3, A4, A5, A6, A7, A8, A9):
    """
    This function calculates He+2 impact ionzation cross sections (in cm2) of 
    H n > 3.
    param E: requested impact energy in keV/u
    type E: float, np.ndarray
    param Ai: fit coefficient 
    type Ai: float
    """
    E = (A9/3)**2*E
    sigma = (A9/3)**4*1e-16 * A1 * (np.exp(-A2/E) * np.log(1 + A3*E) / E + 
                    A4*np.exp(-A5*E)/ (E**A6 + A7*E**A8))
    return sigma

Fit Precision

2.1 %

Fit Coefficients

A1	2.501e+02
A2	7.902e+00
A3	2.145e+06
A4	3.304e-01
A5	9.301e-02
A6	-4.945e-01
A7	6.336e-01
A8	-2.762e+00
A9	5.000e+00

x-range

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DataSet D108175

He2++Hn=5→He2++H++e−

Fitted Data

${He}^{2 +} + H n = 5 \to {He}^{2 +} + H^{+} + e^{-}$