Abstract: A focusing collimator has a plurality of corrugated strips which are built up in a stack. Within each stacking plane of interest, each strip is shaped in cross-section as a part of a different radial sector of a common predetermined annulus.

Abstract: A test pattern device for testing scintillation cameras has a radiation transparent body member with internal mercury-filled communicating passages that define a calibrated radiation opaque test pattern. A peripheral passage serves as a mask to outline the useful field of view of the camera crystal, and expansion chambers accommodate changes in mercury volume due to temperature. The body member is made by securing a plastic cover plate to a plastic base molded with grooves to form the test pattern passages and filling ports, and then sealing the filling ports after mercury has been added to fill the passages. The invention avoids the tolerance problems associated with the manufacture of conventional lead test pattern devices.