Several embodiments of the invention are shown, including {HEAD ~ pairs} of {TAIL ~ reflectors} whose apposed surfaces are convex and concave conic sections or convex and concave spirals 
of
Several embodiments of the invention are shown , including { HEAD ~ pairs } of { TAIL ~ reflectors } whose apposed surfaces are convex and concave conic sections or convex and concave spirals
OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH