e_ioniz_2_janev Function

  1. atomic_tables.f90
  2. atomic_tables
  3. e_ioniz_2_janev

public function e_ioniz_2_janev(eb) result(sigma)

Calculates cross section for a electron-Hydrogen impact ionization from the state at energy eb

Equation

References

Arguments

Type IntentOptional AttributesName
real(kind=Float64), intent(in) :: eb

Collision energy [keV]

Return Value real(kind=Float64)

Cross Section []


Called by

proc~~e_ioniz_2_janev~~CalledByGraph proc~e_ioniz_2_janev e_ioniz_2_janev proc~e_ioniz_n e_ioniz_n proc~e_ioniz_n->proc~e_ioniz_2_janev proc~e_ioniz e_ioniz proc~e_ioniz->proc~e_ioniz_n proc~write_bb_h_e write_bb_H_e proc~write_bb_h_e->proc~e_ioniz program~generate_tables generate_tables program~generate_tables->proc~write_bb_h_e

Contents

Source Code

e_ioniz_2_janev

Source Code

function e_ioniz_2_janev(eb) result(sigma)
    !+Calculates cross section for a electron-Hydrogen impact ionization from
    !+the \(n=2\) state at energy `eb`
    !+
    !+###Equation
    !+$$ e + H(2) \rightarrow e + H^+ + e$$
    !+
    !+###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 = 2
        !+ Initial atomic energy level/state
    real(Float64), dimension(6), parameter :: A = [ 0.14784d0, 0.0080871d0, &
                                                   -0.062270d0, 1.9414d0,   &
                                                   -2.1980d0, 0.95894d0 ]
        !+ 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

    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)
    sigma = max(sigma, 0.d0)

end function e_ioniz_2_janev