DataSet D108178

\[\mathrm{He}^{2+} + \mathrm{H} \; n=8 \rightarrow \mathrm{He}^{2+} + \mathrm{H}^{+} + \mathrm{e}^-\]


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%

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

Fitted Data

Fit Function
Details
\[\sigma_{ion}^{1,2,3}(E) =\Bigg( \frac{A_9}{3}\Bigg)^410^{-16}A_1 \Bigg[\frac{e^{-\frac{A_2}{E_n}}\ln(1+A_3E_n)}{E_n} + \frac{A_4e^{-A_5E_n}}{E_n^{A_6} + A_7E_n^{A_8}}\Bigg]; E_n = \Bigg( \frac{3}{n}\Bigg)^2E\]
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 Precision2.1 %
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
 8.000e+00
x-range –