ADAS Subroutine d4ibal

      SUBROUTINE D4IBAL ( MAXT  , IZ1   , IZ2  ,
     &                    NDZ   , NDTIN ,
     &                    ACDL  , SCDL
     &                  )
C-----------------------------------------------------------------------
C
C  ****************** FORTRAN77 SUBROUTINE: D4IBAL *********************
C
C  PURPOSE: TO CALCULATE IONISATION BALANCES AT FIXED DENSITY
C
C  CALLING PROGRAM: ADAS404
C
C  SUBROUTINE:
C
C  INPUT : (I*4)  MAXT    = NUMBER OF USER ENTERED TEMPERATURES <= NDTIN
C  INPUT : (I*4)  IZ1     = MINIMUM ALLOWED IONIC CHARGE + 1
C                                       (ACCORDING TO AVAILABLE 'NSET')
C  INPUT : (I*4)  IZ2     = MAXIMUM ALLOWED IONIC CHARGE + 1
C
C  INPUT : (I*4)  NDZ     = NUMBER OF CHARGE STATES
C  INPUT : (I*4)  NDTIN   = MAXIMUM NUMBER OF INPUT TEMPERATURES
C
C  I/O   : (R*8)  ACDL(,) = INPUT : LOG10(RECOMB. COLL-DIEL COEFF)
C                           OUTPUT: LOG10(IONISATION-BALANCE)
C                           NOTE:   THESE VALUES ARE FOR A FIXED DENSITY
C                              1ST ARRAY DIMENSION = ION CHARGE/STAGE
C                              2ND ARRAY DIMENSION = TEMPERATURE
C  I/O   : (R*8)  SCDL(,) = INPUT : LOG10(IONIS. COLL-DIEL COEFF)
C                           OUTPUT: IONISATION-BALANCE
C                           NOTE:   THESE VALUES ARE FOR A FIXED DENSITY
C                              1ST ARRAY DIMENSION = ION CHARGE/STAGE
C                              2ND ARRAY DIMENSION = TEMPERATURE
C
C          (I*4)  MAX     = MAXIMUM NUMBER OF CHARGES FOR COLL-DIEL COEF
C          (I*4)  MAX1    = MAXIMUM NUMBER OF CHARGES FOR ION.-BALANCE
C                           ('MAX' + 1)
C          (I*4)  IZ      = ARRAY SUBSCRIPT USED FOR ION CHARGE VALUES
C          (I*4)  IT      = ARRAY SUBSCRIPT USED FOR TEMPERATURE VALUES
C          (I*4)  IREF    = REFERENCE POINT IN COLL-DIEL COEFF ARRAY,
C                           REPRESENTING THE CHARGE BELOW WHICH THE ION.
C                           COLL-DIEL COEFF IS GREATER THAN RECOMB COLL-
C                           DIEL. COEFF..
C
C          (R*8)  S       = USED FOR SUMMING COEFFICIENTS
C          (R*8)  SLOG    = LOG10( 'S' )
C
C
C ROUTINES: NONE
C
C AUTHOR:   PAUL E. BRIDEN (TESSELLA SUPPORT SERVICES PLC)
C           K1/0/81
C           JET EXT. 4569
C
C DATE:     08/10/90
C
C UNIX-IDL PORT:
C
C VERSION: 1.1				DATE: 11-11-96
C MODIFIED: WILLIAM OSBORN (TESSELLA SUPPORT SERVICES PLC)
C		- FIRST CONVERTED
C
C-----------------------------------------------------------------------
C-----------------------------------------------------------------------
      INTEGER             IZ1,         IZ2,         MAXT,        NDTIN
      INTEGER             NDZ
      REAL*8              ACDL(NDZ,NDTIN),          SCDL(NDZ,NDTIN)