ADAS Subroutine pchx

       FUNCTION PCHX(V,L,L1,E)
       IMPLICIT REAL*8(A-H,O-Z)
C-----------------------------------------------------------------------
C
C  PURPOSE: EVALUATES PEACH PHASE X(V,L,E,L1) BY TABLE INTERPOLATION
C
C  TABLES ARE READ IN FROM DISC FILE 'JETSHP.PCHXTAB.DATA' ON FIRST
C  CALL TO PCHX AND STORED IN LABELLED COMMON /PCHXTB/.
C  THE INPUT IS ON STREAM 14.  IFIRST MUST BE SET TO 1 IN MAIN ROUTINE
C  INITIALLY. IT IS RESET TO 0 AFTER TABLES ARE READ IN.
C  ********** H.P. SUMMERS, JET     26 JUNE 1985  ********************
C_______________________________________________________________________
C  INPUT
C      N=EFFECTIVE PRINCIPAL QUANTUM NUMBER OF BOUND STATE
C      L=ORBITAL ANGULAR MOMENTUM OF ELECTRON IN BOUND STATE
C      L1=ORBITAL ANGULAR MOMENTUM OF ELECTRON IN FREE STATE
C      E=ELECTRON ENERGY IN FREE STATE (REDUCED RYDBERG UNITS)
C  OUTPUT
C      PCHX=PEACH INTERPOLATED PHASE
C_______________________________________________________________________
C-----------------------------------------------------------------------
C UNIX-IDL PORT:
C
C AUTHOR:  WILLIAM OSBORN (TESSELLA SUPPORT SERVICES PLC)
C
C DATE:    4TH JULY 1996
C
C VERSION: 1.1                          DATE: 04-07-96
C MODIFIED: WILLIAM OSBORN
C               - FIRST VERSION.
C
C VERSION: 1.2                          DATE: 19-12-01
C MODIFIED: Martin O'MULLANE
C               - Removed junk from > column 72.
C
C VERSION: 1.3                          DATE: 20-07-07
C MODIFIED: Allan Whiteford
C               - Small modification to comments to allow for
C                 automatic documentation preparation.
C
C-----------------------------------------------------------------------
      INTEGER             L,           L1
      REAL*8              E,           V