DataSet D947

\[\mathrm{e}^- + \mathrm{Be} \; 2s4s \; {}^{3}\mathrm{S} \rightarrow \mathrm{Be}^{+} + 2\mathrm{e}^-\]

Process EIN: Ionization
Data type cross section | uploaded on 2022-05-26
Comment Analytic fits for electron-impact ionization cross sections for BeI
RecommendedYes
MethodTheory
Columns
  1. E /eV
  2. sigma /cm2
Uncertainty15 %
Ref
  • B7: Dipti, T. Das, K. Bartschat, I. Bray, D. Fursa, O. Zatsarinny, C. Ballance, H. Chung, Y. Ralchenko, "Recommended electron-impact excitation and ionization cross sections for Be I ", Atomic Data and Nuclear Data Tables 127-128, 1-21 (2019). [10.1016/j.adt.2018.11.001]
DataDownload (data from fit)

Fitted Data

Fit Function
Details		 \[\sigma (x) = \left( \frac{10^{-13}}{xI} \right) \left(A_1 \ln\left( \frac{x}{I} \right) + \displaystyle\sum_{i=2}^{6}A_i\left(1-\frac{I}{x}\right)^{i-1} \right)\]
Python 
def Ion_fit_Be(x  A1, A2, A3, A4, A5, A6, I):
    """
    This function calculates electron impact ionization cross sections (in cm2) of 
    Be I.
    param x: requested electron-impact energy in eV
    type x: float, np.ndarray
    param Ai: fit coefficient 
    type Ai: float
    param I: ionization energy in eV
    type I: float
    """
    sigma = ((1e-13/x/I)*(A1* np.log(x/I) + A2 * (1-(I/x)) + A3 * (1-(I/x))**2 + 
            A4 * (1-(I/x))**3 + A5 * (1-(I/x))**4 + A6 * (1-(I/x))**5)  
    return sigma
Fit Coefficients 
A1
 1.375e-01
A2
 7.384e-01
A3
-6.113e+00
A4
 1.903e+01
A5
-2.127e+01
A6
 7.946e+00
I
 1.325e+00
x-range –