In the illustrated embodiment, {TAIL ~ the inboard and outboard edges} are parallel to each other and perpendicular to the top and bottom edges, with {HEAD ~ the overall plan} of the detector heads being substantially square 
In the illustrated embodiment , { TAIL ~ the inboard and outboard edges } are parallel to each other and perpendicular to the top and bottom edges , with { HEAD ~ the overall plan } of the detector heads being substantially square
OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH