CollisionDB: DataSet D108172

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

Process	HIN: Ionization
Data type	cross section \| uploaded on 2023-02-08
Comment	Fit function taken from p110. Error: E<2keV/u -> 100%, 2keV/u<E<10keV/u -> 40%, 10keV/u<E<100keV/u -> 30%, E<100keV/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) = 10^{- 16} A_{1} [\frac{e^{- \frac{A_{2}}{E}} \ln (1 + A_{3} E)}{E} + \frac{A_{4} e^{- A_{5} E}}{E^{A_{6}} + A_{7} E^{A_{8}}}]

Python

def h_hin_javen_he(E, A1, A2, A3, A4, A5, A6, A7, A8):
    """
    This function calculates He+2 impact ionzation cross sections (in cm2) of 
    H n=1,2 and 3.
    param E: requested impact energy in keV/u
    type E: float, np.ndarray
    param Ai: fit coefficient 
    type Ai: float
    """
    sigma = 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

3.8 %

Fit Coefficients

A1	1.090e+02
A2	2.647e+01
A3	1.022e+06
A4	5.729e-03
A5	4.015e-02
A6	-2.409e+00
A7	1.490e-02
A8	-2.379e-01

x-range

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DataSet D108172

He2++Hn=2→He2++H++e−

Fitted Data

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