e_excit_1_4_janev Function

  1. atomic_tables.f90
  2. atomic_tables
  3. e_excit_1_4_janev

public function e_excit_1_4_janev(eb) result(sigma)

Calculates cross section for a electron-Hydrogen impact excitation transition from the state to 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_excit_1_4_janev~~CalledByGraph proc~e_excit_1_4_janev e_excit_1_4_janev proc~e_excit_1_janev e_excit_1_janev proc~e_excit_1_janev->proc~e_excit_1_4_janev proc~e_excit_n e_excit_n proc~e_excit_n->proc~e_excit_1_janev proc~e_excit_n_m e_excit_n_m proc~e_excit_n_m->proc~e_excit_n proc~e_excit e_excit proc~e_excit->proc~e_excit_n proc~write_bb_h_e write_bb_H_e proc~write_bb_h_e->proc~e_excit program~generate_tables generate_tables program~generate_tables->proc~write_bb_h_e

Contents

Source Code

e_excit_1_4_janev

Source Code

function e_excit_1_4_janev(eb) result(sigma)
    !+Calculates cross section for a electron-Hydrogen impact excitation transition from
    !+the \(n=1\) state to the \(m=4\) state at energy `eb`
    !+
    !+###Equation
    !+$$ e + H(1) \rightarrow e + H(4) $$
    !+
    !+###References
    !+* Eq. 5 and Table 2 in Ref. 2 [[atomic_tables(module)]]
    !+
    real(Float64), intent(in) :: eb
        !+ Collision energy [keV]
    real(Float64)             :: sigma
        !+ Cross Section [\(cm^2\)]

    real(Float64), parameter :: sigma0 = 5.984d0
    real(Float64), parameter :: deltaE = 12.75d0
        !+ Fitting parameter from Table 2 in Ref. 2
    real(Float64), parameter :: alpha = 0.41844d0
        !+ Fitting parameter from Table 2 in Ref. 2
    real(Float64), dimension(5), parameter :: A = [ 0.24300d0, 0.24846d0, &
                                                    0.19701d0, 0.d0,      &
                                                    0.d0 ]
        !+ Fitting parameters from Table 2 in Ref. 2

    real(Float64) :: ecoll, x, s

    ecoll = eb*1.d3
    x=ecoll/deltaE
    s = A(2) + A(3)/x + A(4)/x**2.0 + A(5)/x**3.0

    sigma = 1.d-16 * sigma0/(deltaE*x) * (1.0 - 1.0/x)**alpha * (A(1)*log(x) + s)

    if(x.le.1.0) sigma = 0.d0

end function e_excit_1_4_janev