Calculates total cross section for proton-Hydrogen charge exchange interactions from the state at energy Erel
Type | Intent | Optional | Attributes | Name | ||
---|---|---|---|---|---|---|
real(kind=Float64), | intent(in) | :: | Erel | Relative collision energy [keV/amu] |
Cross Section []
function p_cx_3_janev(Erel) result(sigma)
!+Calculates total cross section for proton-Hydrogen charge exchange interactions from the \(n=3\) state at energy `Erel`
!+
!+###Equation
!+ $$H^+ + H(3) \rightarrow H(\forall m) + H^+$$
!+###References
!+* Eq. 44 and Table 9 in Ref. 2 [[atomic_tables(module)]]
real(Float64), intent(in) :: Erel
!+ Relative collision energy [keV/amu]
real(Float64) :: sigma
!+ Cross Section [\(cm^2\)]
real(Float64), dimension(6), parameter :: a = [3.7271d-1, 2.7645d6, 1.4857d3, &
1.5720d-3, 3.0842d-6, 1.1832d-10 ]
!+ Fitting Parameters from Table 9 in Ref. 2
real(Float64), parameter :: n = 3.d0
real(Float64) :: Ehat
Ehat = Erel * n**2.0
sigma = (1.d-16*a(1)*(n**4))*log(a(2)/Ehat + a(3)) / &
(1.d0+a(4)*Ehat + a(5)*Ehat**(3.5) + a(6)*Ehat**(5.4))
end function p_cx_3_janev