DataSet D108004

\[\mathrm{He}^{2+} + \mathrm{H} \; n=10 \rightarrow \mathrm{He}^{+} + \mathrm{H}^{+}\]


Process HCX: Charge Transfer
Data type cross section | uploaded on 2023-02-08
Comment Fit function taken from p120. Error: E< 1/(n^2) keV/u -> 60%, 1/(n^2) keV/u<E< 25/(n^2) keV/u -> 40%, 25/(n^2) keV/u<E< 200/(n^2) keV/u -> 30%, E>200/(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
\[\sigma_{CX}^{n>2}(E) = A_5^4 \frac{7.04 \times 10^{-16} A_1 \bigg[1 - e^{-\frac{4}{3A_1}\big(1 + \tilde E^{A_2} + A_3 \tilde E^{3.5} + A_4 \tilde E^{5.4}\big) } \bigg]}{1 + \tilde E^{A_2} + A_3 \tilde E^{3.5} + A_4 \tilde E^{5.4}}, \tilde E = EA_5^2\]
Python
def h_hcx_javen_he_scaled(E, A1, A2, A3, A4, A5):
    """
    This function calculates He+2 impact charge exchange cross sections (in cm2) of 
    H n > 2
    param E: requested impact energy in keV/u
    type E: float, np.ndarray
    param Ai: fit coefficient 
    type Ai: float
    """
    E = E/A[4]**2

    sigma = 7.04e-16*A5**4*A1*(1-np.exp(-4/(3*A1)* 
                   1+E**A2+A3*E**3.5+A4*E**5.4)))/(1+E**A2+A3*E**3.5+A4*E**5.4)
    return sigma
Fit Precision2.4 %
Fit Coefficients
A1
 2.003e+02
A2
 1.459e+00
A3
 2.038e-04
A4
 2.000e-09
A5
 1.000e+01
x-range –