| 摘要 |
<p>PURPOSE:To improve detection sensitivity by three-dimensional data collection and processing and to make it possible to obtain high resolution by moving collimators in the direction of the central axis with respect to a gamma-ray detector with the interval being set at a plurality of times of detecting cells. CONSTITUTION:Many gamma-ray detectors 10 are arranged in ring patterns with a specified axis as the center. For example, a plurality of detecting cells which are formed on the detectors 10 each comprising a scintillator 11 and a photomultiplier 12 are provided. The interval between slice collimators 30 (301-303) is made to be about a plurality of times (about 4 times) in the direction of the central axis (a) of the detectors 10. The collimators 30 are reciprocated and moved in the direction of the central axis by the amplitude of 4 pieces of the detectors 10. The numerical aperture of the detector 10 is kept at the large value, and the gamma-ray shielding effect can be maintained. the blocking effect and the detecting efficiency of the oblique incident gamma rays can be made uniform for the detectors 10.</p> |
