-ray gamma-ray camera system for imaging of isotope distribution - esp. in human body, has collimator grating and pref. germanium detectors

摘要

The incident energy passes through the grating collimator and thus forms in its original pattern upon a large number of detector components lying in a plane behind the collimator. Each detector component is typically of high purity p-Ge made by applying an n-contact onto one side and a p-contact onto the opposite side of a flat rectangular crystal. The two faces are grooved in parallel lines but mutually at right angles on the opposite faces. In this way, semiconductor strips are formed on both sides. These two sets of strips are connected to series resistors connected respectively to preamplifier stages, which thus give coordinate output signals in the x and y directions. A voltage is applied across the system, so that each detector component resolves the absorbed photons. The charge values corresp. to the output signals, are summated to give the energy level for the spatial data and energy data. The resolution of the system is obtd. by the collimator grating, which ensures that only radiation which is incident perpendicularly to the collimator passes through, oblique radiation being eliminated and absorbed. The appts. provides high resolution due to the design of the collimator and in addition provides a rapid and simultaneous image.