Illuminant and radiation detector

Abstract

To provide an illuminant for which fluorescence life is short, transparency is high, and luminescence is high, and a radiation detector using the illuminant. Further, to provide an illuminant which is suitable as an illuminant for a radiation detector for gamma rays, x-rays, alpha-rays, and neutron rays, and for which radiation resistance is high, fluorescence attenuating time is short, and fluorescence strength is high, and a radiation detector that uses such illuminant. Provided is an illuminant that has a garnet structure that uses Ce3+ luminescence of a 4f5d level. The illuminant has a garnet structure represented by general formula CexRE3-xM5+yO12+3y / 2 (where, 0.0001<=x<=0.3, 0<=y<=0.5 or 0<=y<=-0.5; M is at least one selected from Al, Lu, Ga, and Sc; and RE is at least one selected from La, Pr, Gd, Tb, Yb, Y, and Lu), and the illuminant includes a garnet illuminant in which at least one type of monovalent or divalent cation is co-doped at a molar ratio of no more than 7000ppm with respect to total cations.

Description

technical field [0001] The present invention relates to a luminous body containing cerium as an activator for absorbing radiation such as γ-rays, X-rays, α-rays, β-rays, and neutron rays or high-energy photons and rapidly converting them into lower-energy photons. Furthermore, the invention relates to a photon detector or radiation detector using the luminophore. Background technique [0002] Illuminants such as scintillators are used in photon detectors or radiation detectors for detecting γ-rays, X-rays, α-rays, β-rays, neutron rays, etc., which are widely used in positron emission tomography Medical imaging equipment such as PET instrument or X-ray CT, various radiation measuring instruments for high-energy physics, resource exploration equipment, etc. [0003] For example, in a positron emission tomography (PET apparatus), a high-sensitivity scintillation detector capable of high-speed response is used to detect high-energy gamma rays (annihilation gamma rays: 511eV) by...

AI Technical Summary

Problems solved by technology

However, it is known that in the Ce-activated garnet-type scintillator, rare earth elements are substituted on the 6-coordinated and 4-coordinated part of the coordination sites, and Al and Ga are substituted on the 8-coordinated part of the coordination sites, causing inversion effect, a defect level originating from the antisite is generated between the band gaps, and the Ce 3+ 4f5d light emission is hindered by the defect level, the amount of light emitted decreases, and a long-lived light-emitting component is produced (for example, please refer to Non-Patent Document 3)

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