DataSet D107514

\[\mathrm{e}^- + \mathrm{Na} \; 2s \rightarrow \mathrm{Na}^{+} + 2\mathrm{e}^-\]

Process EIN: Ionization
Data type cross section | uploaded on 2022-11-11
Comment Fit based on equation (3) based on the Lotz formula
Methodsemi-empirical
Columns
  1. E /eV
  2. sigma /cm2
Threshold67.000 eV
Uncertainty10 %
Ref
  • B47: K. Igenbergs, J. Schweinzer, I. Bray, D. Bridi, F. Aumayr, "Database for inelastic collisions of sodium atoms with electrons, protons, and multiply charged ions ", Atomic Data and Nuclear Data Tables 94, 981-1014 (2008). [10.1016/j.adt.2008.06.001]
DataDownload (data from fit)

Fitted Data

Fit Function
Details		 \[\sigma_{e}^{ion, 2s,2p}(E) = A_1 A_2 10^{-14}\frac{\ln\big(\frac{E}{I}\big)}{EI} \Bigg[1 - A_3e^{-A_4\big(\frac{E}{I}-1\big)} \Bigg]\]
Python 
def na_ein_lotz(E, A1, A2, A3, A4, I):
    """
    This function calculates electron impact ionization cross sections (in cm2) of 
    Na 2s to 2p.
    param E: requested electron-impact energy in eV
    type E: float, np.ndarray
    param Ai: fit coefficient 
    type Ai: float
    param I: ionization energy in eV
    type I: float
    """
    sigma =  1e-14 * A1 * A2 * (np.log(E/I) / (E*I)) * (1 - A3*np.exp(-A4*((E/I)-1)))
    return sigma
Fit Coefficients 
A1
 2.000e+00
A2
 1.080e+01
A3
 4.600e-01
A4
 1.500e+00
I
 6.700e+01
x-range 67.0 –