CollisionDB: DataSet D124005

$e^{-} + {Be}^{+} 3 d^{2} D \to {Be}^{+} 4 f^{2} F + e^{-}$

Process	EEX: Excitation
Data type	cross section \| uploaded on 2024-01-18
Comment	Analytic fits to CCC calculations for electron-impact excitation collision strengths for Be+ as a function of energy in terms of threshold. 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
Threshold	2.6522 eV
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

Ω (x) = A_{1}^{2} \ln (x) + A_{2} + \frac{A_{3}}{x} + \frac{A_{4}}{x^{2}} + \frac{A_{5}}{x^{3}} + \frac{A_{6}}{x^{4}}

Python

def DA_fit_Be1(x, A1, A2, A3, A4, A5, A6):
    """
    This function calculates the dimensionless collision strengths for electron 
    impact excitation of BeII.
    param x: requested electron-impact energy in threshold units
    type x: float, np.ndarray
    param Ai: fit coefficients
    type Ai: float
    """
    Omega = A1**2 * np.log(x) + A2 + A3/x + A4/x**2 + A5/x**3 + A6/x**4
    return Omega

Data Type

collision strength

Fit Coefficients

A1	1.831e+01
A2	-5.672e+02
A3	1.256e+03
A4	-1.448e+03
A5	1.444e+03
A6	-6.459e+02

x-range

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DataSet D124005

e−+Be+3d2D→Be+4f2F+e−

Fitted Data

$e^{-} + {Be}^{+} 3 d^{2} D \to {Be}^{+} 4 f^{2} F + e^{-}$