`pkGetReverseCoef`

## Name

`pkGetReverseCoef`

-- Get the values of reverse reactions properties

## Description

The subroutine `pkGetReverseCoef`

returns a list of values of
a given property for reverse reactions. Two properties are available:

The ratio, in the forward reaction, between the product of the
degeneracy for the `products`

species and the product of the
degeneracy for the `reactants`

species: `'g_ratio'`

;

The energy difference between the products and the reactants in
the forward reaction: `'dE'`

.

## Syntax

pkGetReverseCoef( Property, Value, KReacN[, STAT] )

## Results

The values returned are the values of the property inquired about from among
consecutive `SIZE(``Value`

)

reverse reactions, starting at
species `KReacN`

.

`STAT`

= `0`: no errors;
`STAT`

= `n`: error number.

## Examples

**Example E-7. **`pkGetReverseCoef`

:
Evaluating the electron superelastic cross sections from the corresponding
forward process cross section.

INTEGER :: NfKea, & ! N of forward e-atom reactions
NEbin, & ! N of energy bins
idE, & ! Index for the energy diff. between levels
jmax ! Maximum index for superelastic CS
REAL(double) :: Ebin ! Energy bin
REAL(double), &
ALLOCATABLE :: g2_g1(:), & ! Ratio between degeneracy values
dE(:), & ! Energy difference between levels
CrossSec(:,:) ! Electron collision cross sections
...
NfKea = NKea - NSKea
ALLOCATE( CrossSec(NEbin,NKea) )
IF( NSKea > 0 ) THEN
! - Gets g_ratio and dE for superelastic processes
CALL pkGetReverseCoef( 'g_ratio', g2_g1, NfKea+1 )
CALL pkGetReverseCoef( 'dE', dE, NjKea+1 )
! - Computes superelastic cross sections
DO i = NfKea + 1, NKea
idE = NINT(dE(i)/Ebin); jmax = NEbin-idE
FORALL( j = 1:jmax ) &
CrossSec(j,i) = (1.d0+dE(i)/E(j)) / g2_g1(i) &
* CrossSec(j+idE,Nindex(i))
END DO
END IF