This invention relates to the detection of gamma rays in the core of a nuclear reactor.
There are many well-known means for the detection of gamma rays. However, most of these are either insensitive to the direction of incident gamma rays or else require an extensive length of detector or collimator or both to establish such a directional sensitivity. The fast-neutron hodoscope which includes gamma detectors in each of a number of detection channels is an example of the type of detector that is preceded by a collimator to attenuate all gammas except those proceeding in a favored direction. The collimator in the fast-neutron hodoscope is of the order of meters in length.
It would be useful to have a detector of gamma rays that would identify their energy and direction and that would also be small enough to permit insertion into a measuring region such as the interior of a nuclear reactor. Isotropic detectors exist that are sufficiently small but they are not directional. It would also be useful if the preferred direction could be varied at a measuring region that is sufficiently small in geometric extent to be considered a point or a line.
It is an object of the present invention to provide a method and means of detecting gamma rays that is sensitive to their direction.
It is a further object of the present invention to make a small directional gamma detector.
Other objects will become apparent in the course of a detailed description of the invention.