Details
Nearly all regions in the apparatus are either trapezoidal prisms
arrayed in sectors, or cylindrical shells with circular or polygonal
walls centered on the beam. Trapeziods are specified in a sector-based
coordinate system (see GEOMETRY COORDINATE_SYSTEM) by CORNER(3,ir), the
location of a corner; SIZE(3,ir), dimensions along the 3 axes; and
SLOPE(4,ir), the slopes of the four sides. The latter are given in the
form dx/dy.
Cylinders are specified in the standard coordinate system. RMIN
(or RIN) and RMAX (or ROUT) are the radii of the inner and outer walls.
For polygonal walls, the radius is that to the center of a side. ZMIN
and ZLEN are the starting (minimum) z and the length in z, respectively.