Positron imaging system for plant study

The positron imaging system, which we have developed, is composed of two planar detectors which detect gamma-rays. These are placed on either side of a plant onto which tracers labeled with positron emitting nuclides have been fed. A pair of gamma rays produced by the annihilation of the positrons and electrons is measured simultaneously from both directions, to identify the tracer position. This measurement method enables dynamic movements of substances within the plant to be obtained as a two-dimensional image, without contact. (author)