| 摘要 |
PURPOSE:To enable slice thickness to be change by dividing each high voltage electrode for a radiation detector into plural parts perpendicularly to the direction of electrode arrangement and selectively spplying high voltage to one or both of these parts. CONSTITUTION:After several high-voltage electrodes 5 and signal electrodes 6 alternately arranged are supported by insulating plates 7, the thus obtained structure is installed in a case charged with Xe gas thereby constituting a radiation detector of the multichannel ionization chamber type ued for a third-generation CT device or the like. Each high voltage electrode 5 is made by affixing conductive plates 51 and 52 on both surfaces of an insulating plate 8 in such a manner as to divide the electrode 5 into equal halves perpedicularly to the direction of the electrode arrangement seen from the incidence side of radiation. The plates 51 and 52 are separately connected to high voltages (HV1) and (HV2) respectively. Owing to the above constitution, when obtaining two slices of tomographic images, their thickness can be reduced while realizing effective utilization of X-rays by arbitrarily applying one or both of (HV1) and (HV2) by means of a change-over circuit. |
