ADAS Subroutine rqinew

       FUNCTION RQINEW(Z,N,ZIMP,AMSIMP,TP,VDISP)
C
       IMPLICIT REAL*8(A-H,O-Z)
C
C-----------------------------------------------------------------------
C
C  ****************** FORTRAN77 FUNCTION: RQINEW ***********************
C
C-----------------------------------------------------------------------
C  PURPOSE: EVALUATES ION IMPACT IONISATION RATE COEFFICIENTS FOLLOWING
C           THE EXPRESSIONS OF PERCIVAL AND RICHARDS.
C
C  (ALTERNATIVE TO RQIONPR WITH BETTER MAXWELL AVERAGING BUT SLOWER)
C
C  A CONSTANT SPEED SHIFT MAY BE GIVEN TO THE COLLISION OVER AND ABOVE
C  THE THERMAL SPEEDS
C
C
C  INPUT
C      Z      = TARGET ION CHARGE+1
C      N      = PRINCIPAL QUANTUM  NUMBER OF INITIAL  TARGET LEVEL
C      ZIMP     = PROJECTILE CHARGE
C      AMSIMP = PROJECTILE MASS (PROTON UNITS)
C      TP     = ION TEMPERATURE (K)    (EITHER TARGET OR PROJECTILE)
C      VDISP  = CONSTANT MEAN SPEED SHIFT FOR THE COLLISION
C                     (DESCRIBES BEAM PLASMA SITUATIONS)
C
C  OUTPUT
C      RQINEW  = RATE COEFFICIENT  (CM**3 SEC-1)
C
C
C  ********* H.P. SUMMERS, JET               3  JULY  1991   ***********
C
C NOTES: THIS ROUTINE IS NOT YET PROPERLY ANNOTATED
C
C UNIX-IDL PORT:
C
C VERSION: 1.1                          DATE: 16-1-96
C MODIFIED: TIM HAMMOND (TESSELLA SUPPORT SERVICES PLC)
C               - FIRST VERSION
C
C VERSION: 1.2                          DATE: 08-02-96
C MODIFIED: TIM HAMMOND (TESSELLA SUPPORT SERVICES PLC)
C               - REMOVED SUPERFLUOUS VARIABLES
C
C VERSION: 1.3                          DATE: 16-05-07
C MODIFIED: Allan Whiteford
C             - Updated comments as part of subroutine documentation
C               procedure.
C
C-----------------------------------------------------------------------
C
      INTEGER             N
      REAL*8              AMSIMP,      TP,          VDISP,       Z
      REAL*8              ZIMP