Calculates cross section for a proton-Hydrogen impact excitation transition from
the state to the state at energy eb
Type | Intent | Optional | Attributes | Name | ||
---|---|---|---|---|---|---|
real(kind=Float64), | intent(in) | :: | eb | Relative collision energy [keV/amu] |
Cross Section []
function p_excit_1_2_janev(eb) result(sigma)
!+Calculates cross section for a proton-Hydrogen impact excitation transition from
!+the \(n=1\) state to the \(m=2\) state at energy `eb`
!+
!+###Equation
!+$$ H^+ + H(1) \rightarrow H^+ + H(2) $$
!+
!+###References
!+* Eq. 29.b and Table 4 in Ref. 2 [[atomic_tables(module)]]
!+
real(Float64), intent(in) :: eb
!+ Relative collision energy [keV/amu]
real(Float64) :: sigma
!+ Cross Section [\(cm^2\)]
real(Float64), dimension(10), parameter :: a = [34.433d0, 8.5476d0, &
7.8501d0, -9.2217d0, &
1.8020d-2, 1.6931d0, &
1.9422d-3, 2.9068d0, &
44.507d0, 0.56870d0 ]
!+ Fitting parameters from Table 4 in Ref. 2
sigma = 1.d-16 * a(1) * ( a(2)*exp(-a(3)*eb)/(eb**a(4)) + &
a(5)*exp(-a(6)/eb)/(1.+a(7)*eb**a(8)) + &
exp(-a(9)/eb)*log(1.+a(10)*eb)/eb )
end function p_excit_1_2_janev