Calculates the generic total ionization cross section for a Neutral Hydrogen atom
in the n
state colliding with a ion with charge q
at energy eb
Type | Intent | Optional | Attributes | Name | ||
---|---|---|---|---|---|---|
real(kind=Float64), | intent(in) | :: | eb | Relative collision energy [keV/amu] |
||
integer, | intent(in) | :: | q | Ion charge |
||
integer, | intent(in) | :: | n | Initial atomic energy level/state |
Cross Section []
function Aq_ioniz_n_janev(eb, q, n) result(sigma)
!+ Calculates the generic total ionization cross section for a Neutral Hydrogen atom
!+in the `n` state colliding with a ion with charge `q` at energy `eb`
!+
!+###Equation
!+$$ A^{q+} + H(n) \rightarrow A^{q+} + H^+ + e, n \gt 1, q \gt 3 $$
!+
!+###References
!+* Page 160 in Ref. 5 [[atomic_tables(module)]]
real(Float64), intent(in) :: eb
!+ Relative collision energy [keV/amu]
integer, intent(in) :: q
!+ Ion charge
integer, intent(in) :: n
!+ Initial atomic energy level/state
real(Float64) :: sigma
!+ Cross Section [\(cm^2\)]
real(Float64), parameter :: M = 0.283d0
real(Float64), parameter :: B = 4.04d0
real(Float64), parameter :: c = 137.d0
real(Float64), parameter :: g = 0.662d0
real(Float64), parameter :: lambda = 0.76d0
real(Float64) :: nf, qf, u, v, sigma_b
nf = real(n)
qf = real(q)
v = sqrt(eb/25.)
u = nf*v
sigma_b = 3.52d-16 * (nf**4) * (qf**2)/(u**2) * &
(M * (log((u**2)/(c**2 - u**2)) - (u**2)/(c**2)) + B - g/u**2)
sigma_b = max(sigma_b,0.d0)
sigma = exp(-lambda*qf/u**2)*sigma_b
end function Aq_ioniz_n_janev