Final implementation of ionization process by electron impact.

Possibility to input initial species distributions (density, velocity
    and temperature) via an input file for each species.

New moduleRandom includes function to generate random numbers in
different ways (still uses) the implicit RANDOM_NUMBER().

src/modules/mesh/1DRad/moduleMesh1DRad.f90

@@ -75,7 +75,7 @@ MODULE moduleMesh1DRad
       PROCEDURE(dPsi_interface), DEFERRED, NOPASS:: dPsi
       PROCEDURE(partialDer_interface), DEFERRED, PASS:: partialDer
   
-  END TYPE meshVol1Drad
+  END TYPE meshVol1DRad
 
   ABSTRACT INTERFACE
     PURE FUNCTION fPsi_interface(xi) RESULT(fPsi)
@@ -111,6 +111,7 @@ MODULE moduleMesh1DRad
     REAL(8):: arNodes(1:2)
     CONTAINS
       PROCEDURE, PASS::   init        => initVol1DRadSegm
+      PROCEDURE, PASS::   randPos     => randPos1DRadSeg
       PROCEDURE, PASS::   area        => areaRad
       PROCEDURE, NOPASS:: fPsi        => fPsiRad
       PROCEDURE, NOPASS:: dPsi        => dPsiRad
@@ -266,6 +267,24 @@ MODULE moduleMesh1DRad
 
     END SUBROUTINE initVol1DRadSegm
 
+    !Calculates a random position in 1D volume
+    FUNCTION randPos1DRadSeg(self) RESULT(r)
+      USE moduleRandom
+      IMPLICIT NONE
+
+      CLASS(meshVol1DRadSegm), INTENT(in):: self
+      REAL(8):: r(1:3)
+      REAL(8):: xii(1:3)
+      REAL(8), ALLOCATABLE:: fPsi(:)
+
+      xii(1)   = random(-1.D0, 1.D0)
+      xii(2:3) = 0.D0
+
+      fPsi = self%fPsi(xii)
+      r(1) = DOT_PRODUCT(fPsi, self%r)
+
+    END FUNCTION randPos1DRadSeg
+
     !Computes element area
     PURE SUBROUTINE areaRad(self)
       IMPLICIT NONE