DataSet D107520

\[\mathrm{e}^- + \mathrm{Na} \; 4p \rightarrow \mathrm{Na}^{+} + 2\mathrm{e}^-\]

Process EIN: Ionization
Data type cross section | uploaded on 2022-11-11
Comment Fit based on equation (2). The cross-section was attribited 10% reltive error based on experience featured in Schweinzer et al. ADNDT 72 239 1999.
MethodCCC: Convergent close-coupling
Columns
  1. E /eV
  2. sigma /cm2
Threshold1.386 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		 \[\sigma_{e}^{ion, Na}(E) = \frac{10^{-13}A_7}{I_{nl}E}\Bigg[A_5 \ln\bigg( \frac{E}{I_{nl}} \bigg) + A_6 e^{-\frac{E}{I_{nl}}}+ \sum_{j=1}^{4}A_j\bigg(1-\frac{I_{nl}}{E}\bigg)^{j-1} \Bigg]\]
Python 
def na_ein(E, A1, A2, A3, A4, A5, A6, A7, I):
    """
    This function calculates electron impact ionization cross sections (in cm2) of 
    Na 3s to 5s.
    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 =  A7*1e-13/(E*I) * (A5*np.log(E/I) + A6 * np.exp(-E/I) + A1*(1 - I/E)**0 + 
                               A2*(1 - I/E)**1 + A3*(1 - I/E)**2 + A4*(1 - I/E)**3)
    return sigma
Fit Coefficients 
A1
-2.890e+01
A2
-6.495e+00
A3
 1.302e+02
A4
-9.229e+01
A5
 1.925e-01
A6
 9.113e+01
A7
 1.763e-01
I
 1.386e+00
x-range 1.9 –