DataSet D124008

\[\mathrm{e}^- + \mathrm{Be}^{+} \; 4d \; {}^{2}\mathrm{D} \rightarrow \mathrm{Be}^{+} \; 4f \; {}^{2}\mathrm{F} + \mathrm{e}^-\]

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 %.
RecommendedYes
MethodCCC: Convergent close-coupling
Columns
  1. E /eV
  2. sigma /cm2
Threshold0.0031 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]
DataDownload

Fitted Data

Fit Function
Details		 \[\Omega (x) = A_1^2 \ln(x) + A_2 + \frac{A_3}{x} + \frac{A_4}{x^2} + \frac{A_5}{x^3} + \frac{A_6}{x^4}\]
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 Typecollision strength
Fit Coefficients 
A1
 2.772e+01
A2
 5.366e+02
A3
-4.345e+04
A4
 1.869e+06
A5
-1.996e+07
A6
 9.990e-01
x-range 22.0 –