Code |
c
c###################################################################
c
subroutine hexc2(pe, pcf, kncf, pxs, kermsg)
c
c this is a subroutine to calculate cross sections (cm[2])
c versus projectile energy (ev) for heavy particle collisions.
c
c pe = collision energy in kev/amu
c
c pcf(1-10) = parameters for fit to the cross section
c
c kermsg = blank if no errors
c
c pxs = cross section in 10e-16 cm[2]
c------------------------------------------------------------------------
c
double precision pe, pcf, pxs
double precision e, a1, a2, a3, a4, a5, a6, arg1, arg2, arg3
double precision a7, a8, a9, a10, c1, c2, c3, dexpr, zero, one
c
dimension pcf(10)
character*(*) kermsg
data dexpr/7.00d+02/
data zero/0.00d+00/
data one/1.00d+00/
c
c generate e, the energy in kev
c
e = pe
a1= pcf(1)
a2= pcf(2)
a3= pcf(3)
a4= pcf(4)
a5= pcf(5)
a6= pcf(6)
a7= pcf(7)
a8= pcf(8)
a9= pcf(9)
a10= pcf(10)
arg1=-a2/e
c1=zero
if (dabs(arg1) .lt. dexpr) c1=dexp(arg1) * dlog(one+(a3*e))/e
c
arg2=-a5*e
c2=zero
if (dabs(arg2) .lt. dexpr) c2=a4*dexp(arg2)/(e**a6)
c
arg3=-a8/e
c3=zero
if (dabs(arg3) .lt. dexpr) c3= a7*dexp(arg3)/
1 (one + a9*(e**a10))
c
pxs=a1*(c1 + c2 + c3)
return
end |