DataSet D775

\[\mathrm{e}^- + \mathrm{Be} \; 2s^{2} \; {}^{1}\mathrm{S} \rightarrow \mathrm{Be} \; 2s3d \; {}^{1}\mathrm{D} + \mathrm{e}^-\]

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
RecommendedYes
MethodTheory
Columns
  1. E /eV
  2. sigma /cm2
Threshold7.9881 eV
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		 \[\Omega (x) = \left( \frac{x (x - 1)}{x^2 + A_1} \right) \left(A_2 + \frac{A_3}{x} + \frac{A_4}{x^2} + \frac{A_5}{x^3} + \frac{A_6}{x^4}\right)\]
Python 
def DF_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*(x-1)/(x**2 + A1))*(A2 + A3/x + A4/x**2 + A5/x**3 + A6/x**4)
    return Omega
Data Typecollision strength
Fit Coefficients 
A1
-9.979e-01
A2
 6.209e-02
A3
 1.875e+00
A4
-3.485e+00
A5
 8.006e-01
A6
 8.741e-01
x-range –