CollisionDB: DataSet D108117

$H^{+} + H n = 3 \to H + H^{+}$

Process	HCX: Charge Transfer
Data type	cross section \| uploaded on 2023-02-08
Comment	Fit function taken from p80. Error: E< 0.1/n^2 keV/u -> 40%, 0.1/n^2 keV/u < E < 40/n^2 keV/u -> 30%, 40, E< 40/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_{C X}^{n > 1} (E) = \frac{A_{7}^{4} 10^{- 16} A_{1} \ln (\frac{A_{2}}{\tilde{E}} + A_{6})}{1 + A_{3} \tilde{E} + (A_{4} \tilde{E})^{3.5} + (A_{5} \tilde{E})^{5.4}}, \tilde{E} = E A_{7}^{2}

Python

def h_hcx_janev_scaled(E, A1, A2, A3, A4, A5, A6, A7):
    """
    This function calculates proton impact charge exchange cross sections (in cm2) of 
    H n>1.
    param E: requested electron-impact energy in keV
    type E: float, np.ndarray
    param Ai: fit coefficient 
    type Ai: float
    """
    e = E*A7**2
    sigma = A7**4 * 1e-16 * A1 * np.log(A2/e + A6) / 
    (1 + A3*e +(A4*e)**3.5 + (A5*e)**5.4)
    return sigma

Fit Coefficients

A1	3.727e-01
A2	2.764e+06
A3	1.572e-03
A4	2.664e-02
A5	1.451e-02
A6	1.486e+03
A7	3.000e+00

x-range

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DataSet D108117

H++Hn=3→H+H+

Fitted Data

$H^{+} + H n = 3 \to H + H^{+}$