Calculates cross section for a electron-Hydrogen impact ionization from
the state at energy eb
Type | Intent | Optional | Attributes | Name | ||
---|---|---|---|---|---|---|
real(kind=Float64), | intent(in) | :: | eb | Collision energy [keV] |
Cross Section []
function e_ioniz_3_janev(eb) result(sigma)
!+Calculates cross section for a electron-Hydrogen impact ionization from
!+the \(n=3\) state at energy `eb`
!+
!+###Equation
!+$$ e + H(3) \rightarrow e + H^+ + e$$
!+
!+###References
!+* Eq. 14 and Table 3 in Ref. 2 [[atomic_tables(module)]]
!+
real(Float64), intent(in) :: eb
!+ Collision energy [keV]
real(Float64) :: sigma
!+ Cross Section [\(cm^2\)]
integer, parameter :: n = 3
!+ Initial atomic energy level/state
real(Float64), dimension(6), parameter :: A = [0.058463d0, -0.051272d0, &
0.85310d0, -0.57014d0, &
0.76684d0, 0.00d0 ]
!+ Fitting parameters from Table 3 in Ref. 2
real(Float64) :: Edn2
real(Float64) :: e, x
real(Float64) :: s
Edn2 = 13.6/real(n)**2
e = eb * 1.d3 !keV to eV
if(e.ge.1.5) then
x = (1.0 - Edn2/e)
s = A(2)*x + A(3)*(x**2.0) + A(4)*(x**3.0) + A(5)*(x**4.0) + A(6)*(x**5.0)
sigma = ((1.d-13)/(Edn2*e))*(A(1)*log(e/Edn2) + s)
else
sigma = 0.d0
endif
end function e_ioniz_3_janev