CollisionDB: DataSet D824

$e^{-} + Be 2 s 3 p^{1} P \to Be 2 s 4 f^{3} F + e^{-}$

Process	EEX: Excitation
Data type	cross section \| uploaded on 2022-05-26
Comment	Analytic fits for electron-impact excitation collision strengths for BeI as a function of energy in terms of threshold
Recommended	Yes

Method	Theory
Columns	E /eV sigma /cm²
Threshold	0.99852 eV
Uncertainty	15 %
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]
Data	Download (data from fit)

Fitted Data

Fit Function
Details

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

Python

def SF_fit_Be(x, A1, A2, A3, A4, A5, A6):
    """
    This function calculates the dimensionless collision strengths for electron 
    impact excitation of BeI.
    param x: requested electron-impact energy in threshold units
    type x: float, np.ndarray
    param Ai: fit coefficients
    type Ai: float
    """
    Omega = ((x - 1)/(x**A1 + A2))*(A3 + A4/x + A5/x**2 + A6/x**3)
    return Omega

Data Type

collision strength

Fit Coefficients

A1	3.944e+00
A2	4.069e+05
A3	2.086e+03
A4	-9.609e+04
A5	2.073e+06
A6	5.517e+06

x-range

–

DataSet D824

e−+Be2s3p1P→Be2s4f3F+e−

Fitted Data

$e^{-} + Be 2 s 3 p^{1} P \to Be 2 s 4 f^{3} F + e^{-}$