| |
| subroutine interp (matl,dnt,temp,opacity) |
| c*********************************************************************** |
| c calculates material opacities as a function of temperature and |
| c density by interpolating in the llnl library. |
| c arguments: |
| c matl: material number |
| c temp: temperature (units?), |
| c dnt : density (units?) |
| c returns: 13 group opacity vector into array opacity. |
| c*********************************************************************** |
| implicit double precision (a-h,o-z) |
| |
| common /opactab/ x(14,32,13,4), t(32,2), d(14) |
| dimension opacity(13) |
| c scatter, shared opacity |
| |
| |
| ityp = 1 |
| if (matl .eq. 2 .or. matl .eq. 4) ityp = 2 |
| |
| c--------------------find bounding temperatures |
| do 20 it = 1,32 |
| if (temp .lt. t(it,ityp)) goto 30 |
| 20 continue |
| 30 tmax = t(it,ityp) |
| it1 = it-1 |
| tmin = t(it1,ityp) |
| trat = (temp - tmin)/(tmax - tmin) |
| |
| c--------------------find bounding densities |
| do 40 id = 1,14 |
| c if (dnt .lt. d(id)) goto 50 Replaced with following due to |
| c addressing problems |
| if (dnt .le. d(id)) goto 50 |
| 40 continue |
| 50 dmax = d(id) |
| id1 = id-1 |
| dmin = d(id1) |
| drat = (dnt - dmin)/(dmax - dmin) |
| |
| c--------------------interpolate |
| do 60 ie = 1,13 |
| xt = x(id1,it,ie,matl) + (x(id,it,ie,matl)-x(id1,it,ie,matl)) |
| | * drat |
| xt1 = x(id1,it1,ie,matl) |
| | + (x(id,it1,ie,matl)-x(id1,it1,ie,matl))*drat |
| opacity (ie) = exp(xt1 + (xt-xt1)*trat) |
| 60 continue |
| |
| return |
| end |
