DataSet D782

\[\mathrm{e}^- + \mathrm{Be} \; 2s^{2} \; {}^{1}\mathrm{S} \rightarrow \mathrm{Be} \; 2s4f \; {}^{1}\mathrm{F} + \mathrm{e}^-\]

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
Threshold8.46084 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		 \[\Omega (x) = \left( \frac{x - 1}{x + A_1} \right) \left(A_2 \ln(x) + A_3 + \frac{A_4}{x} + \frac{A_5}{x^2} + \frac{A_6}{x^3} \right)\]
Python 
def DA_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 * np.log(x) + A3 + A4/x + A5/x**2 + A6/x**3)
    return Omega
Data Typecollision strength
Fit Coefficients 
A1
-9.995e-01
A2
 1.621e-05
A3
 1.498e-02
A4
 1.164e-01
A5
-3.429e-01
A6
 2.331e-01
x-range –