Limit2.for

      SUBROUTINE LIMIT2
      INCLUDE 'Soldiv.fi'
      PARAMETER (IINT = 4)

C		CALCULATES DENSITY LIMIT OF EQ.(16)


C	EFFECTIVE CIRCULAR RADIUS
      SE = SQRT((1.+ELONG**2)/2.)
C	RADIAL HEAT DIFFUSIVITIES FOR USE IN DISRUPTION ANALYSIS
C		INPUT CHIRC
      CHIRCORE(1) = CHIRC
      CHIRCORE(1) = 1.0
C		CONSISTENT HEAT REMOVAL CHIR USING EXP LT^-1 IN PEDESTAL
      CHIRCORE(2) = FCOND*FLUXHEAT/(XNPED*XK*TPED*GRADTBAR(3))
      CHIRCORE(2) = 0.5
C		CONSISTENT HEAT REMOVAL CHIR USING EXP LT^-1 IN TRANS BARRIER
      CHIRCORE(3) = FCOND*FLUXHEAT/(XNBAR*XK*TBAR*GRADTBAR(4))

      CHIRCORE(3) =0.25
C		CONSISTENT HEAT REMOVAL CHIR USING CORE NET HEAT REMOVAL


      CHIRCORE(4) = FCOND*FLUXHEAT*AMINOR/
     2(XNAV*(T0-TPED)*XK)
      CHIRCORE(4) = 0.1
      DO 60 J=1,4
        CHIR = CHIRCORE(J)
        DRCORE = CHIR
C	SOLVE QUADRATIC EQUATIONS
        BB = CHIR*((5.5/(SE*AMINOR))**2)
        X = 4.*(-1.*HEAT)*(-1.*RAD)/(BB**2)
        IF(X.LE.-1.) GOTO 25
        Y = SQRT(1. + X)
        DEN1(J) = -1.0*BB*(1 + Y)/(2.*RAD)
C		EVALUATE N-T INSTABILITY DENSITY LIMIT
C		EQS. 39 & 40
 25     A = 3.*TJ0*(SN - DRCORE*((5.5/(SE*AMINOR))**2)) + 2.*RADN
        B=3.*XNJ0*(SN-DRCORE*((5.5/(SE*AMINOR))**2))+3.*TJ0*ST-HEAT+RADN2
        C = 3.*XNJ0*ST
        YP = -1.*B*(1. + SQRT(1.-4.*A*C/(B**2)))/(2.*A)
        YM = -1.*B*(1. - SQRT(1.-4.*A*C/(B**2)))/(2.*A)
C		EQ. 44
C	XN0	= (1.+ALPHAN)*XNAV - ALPHAN*XNPED
        G = XNJ0/XN0
        FF = 1. + ALPHAN -ALPHAN*XNPED/XNAV
        AAP = (CHIR*((5.5/(SE*AMINOR))**2)*G + 2.*YP*RADN/XN0)/
     2         (-2.*RADN2/(XN0**2))
        AAM = (CHIR*((5.5/(SE*AMINOR))**2)*G + 2.*YM*RADN/XN0)/
     2         (-2.*RADN2/(XN0**2))
        BBP = (4.*HEAT*RADN2/(XN0**2))/((CHIR*((5.5/(SE*AMINOR))**2)*G
     2  +   2.*YP*RADN/XN0)**2)
        BBM = (4.*HEAT*RADN2/(XN0**2))/((CHIR*((5.5/(SE*AMINOR))**2)*G
     2  +  2.*YM*RADN/XN0)**2)

        IF(BBP.LE.-1.) GOTO 50
        DEN2PP(J) = AAP*(1. + SQRT(1. + BBP))/FF
        DEN2PM(J) = AAP*(1. - SQRT(1. + BBP))/FF
 50     IF(BBM.LE.-1.) GOTO 60
        DEN2MP(J) = AAM*(1. + SQRT(1. + BBM))/FF
        DEN2MM(J) = AAM*(1. - SQRT(1. + BBM))/FF
 60   CONTINUE
 100  FORMAT (4E12.4)
      RETURN
      END