ADAS Subroutine bornp1

       SUBROUTINE BORNP1(NMIN,NMAX,NLOW,LLOW,NUP,LUP,LAM,ANS,QA,IOPT,
     &IMAX1)
       IMPLICIT REAL*8(A-H,O-Z)
C-----------------------------------------------------------------------
C  PURPOSE: FIRST STAGE OF BORN X-SECT CALCULATION WITH DIRECTIONAL
C  BEAMS CAUSING TRANSITIONS BETWEEN HYDROGEN STARK/ZEEMAN STATES.
C
C  RADIAL INTEGRALS OF FORM P(N1,L1)*P(N2,L2)*J(LAM,Q*R) ARE EVALUATED
C  FOR ALL HYDROGENIC ORBITALS WITH NMIN<=NMAX AND N1<N2 FOR A SET
C  OF Q'S SPANNING THE EXTENT OF THE GENERALISED OSCILLATOR STRENGTH
C
C  CALLING ROUTINE WITH IOPT=1 PREPARES LOOKUP TABLES. CALL WITH IOPT=2
C  RETURNS VALUES.
C
C  MATRIX ELEMENT EVALUATION USES POWER SERIES ROUTINES.
C
C  STACK INTEGRALS OVER A GRID OF MOMENTUM CHANGE FROM 10**-2 TO 10**2
C  EQUALLY SPACED IN THE LOGARITHM (IMAX INTERVALS, IMAX+1 VALUES)
C
C  EVALUATE MULTIPOLES UP TO LAMMX=2
C
C  USE POINTER VECTORS FOR RAPID LOOKUP.
C
C  THE MAIN CALLING ROUTINE MUST HAVE THE LINE
C      CALL GAMAF(200)
C  BEFORE CALL TO BORNP1
C
C  ******** H.P. SUMMERS, JET          17 OCT 1988   *************
C  INPUT
C      NMIN=LOWEST N-SHELL
C      NMAX=HIGHEST N-SHELL
C      NLOW=LOWER N FOR SELECTED TRANSITION
C      LLOW=LOWER L FOR SELECTED TRANSITION
C      NUP=UPPER N FOR SELECTED TRANSITION
C      LUP=UPPER L FOR SELECTED TRANSITION
C      LAM=REQUIRED MULTIPOLE (0<=LAM<=LAMMX)
C      IOPT=1  PREPARE LOOKUP STACKS (ONLY NMIN,NMAX PARAMETERS USED)
C          =2  SUPPLY ANSWERS FOR SPECIFIED NLOW,LLOW,NUP,LUP,LAM CASE
C  OUTPUT
C      ANS(I)=BORN APPROXIMATION RESULT FOR I=1,IMAX+1
C      QA(I)=TRANSFERED MOMENTUM VECTOR
C      IMAX1=IMAX+1
C
C-----------------------------------------------------------------------
C
C ADAS305 version. Developed from JETSHP.STARK.FORT (H P Summers).
C
C VERSION  : 1.1
C DATE     : 24-02-2005
C MODIFIED : Martin O'Mullane
C             - First version.
C             - Change dimensions from 200 to 500.
C
C VERSION  : 1.2
C DATE     : 16-05-2007
C MODIFIED : Allan Whiteford
C             - Updated comments as part of subroutine documentation
C               procedure.
C
C----------------------------------------------------------------------
      INTEGER             IMAX1,       IOPT,        LAM,         LLOW
      INTEGER             LUP,         NLOW,        NMAX,        NMIN
      INTEGER             NUP
      REAL*8              ANS(41),     QA(41)