CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
C									C
C  SUBROUTINE    F I E L D _ C O N S T					C
C 									C
C  PURPOSE:  	CONSTANT MAGNETIC FIELD VALUES FOR PARTICLE TRACKING	C
C									C
C  WRITTEN BY:  B.A.M.							C
C									C
C  DATE:  	24-AUG-91						C
C									C
C     CHANGES: 		WHAT				WHO  WHEN       C
C               Unix Compatible Version			BAM  05/11/00   C
C									C
C									C
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
C        1         2         3         4         5         6         7         8
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C
        SUBROUTINE FIELD_CONST(X,B,RI,CHAR,P,FAC,IOUT,ICONT)
ckm              FIELD(XA,BVEK,RI,1.,1.,1.,0,    1)
        SAVE
	DIMENSION B(3),X(3),RI(3)
C
C  X		COORDINATE
C  B		MAGNETIC FIELD IN TESLA
C  RI		INVERSE RADIUS IN M**(-1)
C  CHAR  	CHARGE IN UNITS OF E
C  P		MOMENTUM IN GEV/C
C  FAC  	COMMON FACTOR FOR THE MAGNETIC FIELD
C  ICONT	CONTROLLING THE FUNCTION OF THE SUBROUTINE
C  icount=1   : initialization


        print *, ' starting field_const' 
        GOTO(100,200,300),ICONT
100     CONTINUE

	PI=P
C  PARAMETERS OF THE FAST DIPOLE FOR THE CLAS++ CENTRAL DETECTOR
c     update with values for Hall D solenoid 
c     ES 10/01/06
c
	XMIN=0.0 
c        XMAX=0.5
        XMAX=0.95
c
c       B field used in simulation
c
c	B0=2.0
	B0=1.74
        RETURN
C
200     CONTINUE
C
	IF((X(3).GE.XMIN).AND.(X(3).LE.XMAX)) THEN
		BB=B0
	ELSE
		BB=0.
	ENDIF 
	B(1)=0.
	B(2)=0.
	B(3)=BB
C
        DO 1 I=1,3
        RI(I)=B(I)*CHAR*.2997925/PI	    ! 1/R IN 1/METER
1       CONTINUE
C
        print *, ' at write field_const'
        print 1001,  (X(II),II=1,3),(B(II),II=1,3)
	WRITE(3,1001) (X(II),II=1,3),(B(II),II=1,3)
1001	FORMAT(' X,B ',6F10.4)	
        RETURN
300     CONTINUE
        RETURN
        END