CollisionDB: DataSet D123982

$e^{-} + {Be}^{+} 2 s^{2} S \to {Be}^{2 +} + 2 e^{-}$

Process	EIN: Ionization
Data type	cross section \| uploaded on 2024-01-18
Comment	Analytic fits for electron-impact ionization cross sections for Be+. The cross sections calculations take into account of ioinzation of valence electron as well as core 1s electrons. The uncertainty in the original cross sections is 10 %, while the fitted ones have a total uncertainty of 15 %.
Recommended	Yes

Method	CCC: Convergent close-coupling
Columns	E /eV sigma /cm²
Ref	B227: Dipti, I. Bray, D. Fursa, H. Umer, C. Hill, Y. Ralchenko, "Recommended electron-impact excitation and ionization cross sections for Be II", Atomic Data and Nuclear Data Tables, 101634 (2024). [10.1016/j.adt.2023.101634]
Data	Download

Fitted Data

Fit Function
Details

σ (x) = (\frac{10^{- 13}}{x I}) (A_{1}^{2} \ln (\frac{x}{I}) + \sum_{i = 2}^{6} A_{i} {(1 - \frac{I}{x})}^{i - 1})

Python

def Ion_fit_Be1(x  A1, A2, A3, A4, A5, A6, I):
    """
    This function calculates electron impact ionization cross sections (in cm2) of 
    Be II.
    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**2 * 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

Data Type

cross section

Fit Coefficients

A1	4.258e-01
A2	2.715e-02
A3	-4.927e-02
A4	2.756e+00
A5	-6.168e+00
A6	3.923e+00

x-range

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DataSet D123982

e−+Be+2s2S→Be2++2e−

Fitted Data

$e^{-} + {Be}^{+} 2 s^{2} S \to {Be}^{2 +} + 2 e^{-}$