!------------------------------------------------------------------------------
!
real(fp) FUNCTION SVTHE_Z(TEMP)
!	3/8/77
!============
! idecl:  explicitize implicit INTEGER declarations:
  use iso_c_binding, only: fp => c_double
  use sigtabl_mod, only :A,B,CON,EPS,ITER,IW
  IMPLICIT NONE
  INTEGER j
!============
! idecl:  explicitize implicit REAL declarations:
 real(fp) temp,emin,emax,fsvth_z,ans
 EXTERNAL FSVTH_Z
!	THIS FUNCTION WAS WRITTEN BY HARRY H. TOWNER OF THE PRINCETON
!	PLASMA PHYSICS LAB.  THIS ROUTINE WILL INTEGRATE FUNCTION
!	FSVTH AND CALCULATE <SIGMA*V> FOR THERMAL REACTIONS.  NOTE
!	THAT THIS ROUTINE ASSUMES THAT FUNCTION SVTH WAS PREVIOUSLY
!	CALLED IN ORDER TO INITIALIZE PARAMETERS.
!	PARAMETERS:
!	TEMP - THE TEMPERATRUE AT WHICH YOU WANT <SIGMA*V>.  (KEV)
!	PARAMETER LIST FOR COMMON BLOCK CSVTH.
!	A - =RMASS/TMASS.  (SEE SVTH)
!	B - = A/TEMP
!	CON1 - =CON*A**1.5/SQRT(TMASS).  (SEE SVTH)
!	EPS - THE DESIRED RELATIVE ERROR IN THE REACTIVITY
!	ITER - THE MAXIMUM NUMBER OF ITERATIONS TO BE TAKEN IN ORDER
!	IW - THE LOGICAL UNIT USED FOR PRINTING.
 SVTHE_Z=0.0_fp
 IF(TEMP.LT.0.1_fp) return
!	I NOW CALCULATE B.
 B=A/TEMP
 EMIN=0.0_fp
 EMAX=180.0_fp/B
!	I NOW INTEGRATE FSVTH IN ORDER TO FIND <SIGMA*V>.
 CALL GAUS32_Z(EMIN,EMAX,FSVTH_Z,ANS,EPS,ITER,J,IW)
!  J is output from gaus32_z
!	I NOW COMPUTE <SIGMA*V> (M**3/SEC).
 SVTHE_Z=CON*ANS/TEMP**1.5_fp
 RETURN
END FUNCTION SVTHE_Z
!
!------------------------------------------------------------------------------
! 30Jun2000 fgtok -s r8_precision.sub "r8con.csh conversion"
