### Fit Function: JBORN2

 Fit Function $\sigma = pcf(3) \left(\frac{pcf(1)}{pe}\right) ^{pcf(3)pcf(4)}\ln\left(\frac{pe}{pcf(1)}\right)$ Comments

#### Fortran

Arguments
namedescriptionunitstype(s)
pe requested energy eV real, dimension(:)
pcf coefficient data array real, dimension(11)
kncf number of coefficients in the data array integer
pfit cross section cm2 real, dimension(:)
kermsg error message character
Return values
namedescriptionunitstype(s)
pfit cross section cm2 real, dimension(:)
Code
c
c###################################################################
c
subroutine jborn2(pe, pcf, kncf, pfit, kermsg)
c
c     this is a subroutine to calculate cross sections (cm[2])
c     versus energy (ev) using a formula based on a semiempirical
c     modification of the bethe-born formula.
c     (this expression is identical to that used in jborn1, however,
c      to be able to uniquely identify the different choices of
c      weighting seperate routines have been kept, see
c      doc=h-he-plasma)
c
c     pcf is the coefficient data array, where
c
c     pcf(1) =   the threshold energy for the reaction (ev)
c
c     pcf(2) =    the minimum energy for the application of the
c                 semiempirical formulae.
c
c     pcf(3)  =   coefficient a
c
c     pcf(4)  =   coefficient n
c
c     pe = collision energy in ev
c
c     kermsg = blank if no errors
c
c     pfit = cross section in cm[2]
c
c     written by j. j. smith , iaea atomic and molecular data unit
c
c------------------------------------------------------------------------
c
double precision pe, pcf, pfit
dimension pcf(11)
character*(*) kermsg

eth=pcf(1)
emin = pcf(2)
a=pcf(3)
n=pcf(4)
an=n
if(pe .ge. eth) then
kermsg = ' '
else
kermsg = 'energy is below threshold for reaction in jborn2'
return
endif
c
pfit = a*((eth/pe)**an) *dlog(pe/eth)
100 return
c
end

#### Python

Arguments
namedescriptionunitstype(s)
pe requested energy eV float, np.ndarray
pcf coefficient data array float, np.ndarray
kncf number of coefficients in the data array int
pfit cross section cm2 float, np.ndarray
kermsg error message str
Return values
namedescriptionunitstype(s)
pfit cross section cm2 float, np.ndarray
Code