Photostimulable Storage Phosphor Materials and Their Application to Radiation Monitoring

Nanto Hidehito

doi:10.18494/sam.2018.1803

Abstract

Photostimulable Storage Phosphor Materials and Their Application to Radiation Monitoring

Highlights

Ionizing radiation, such as alpha-rays, beta-rays, X-rays and gamma-rays, and heavy ions, has been used for many industrial and scientific purposes
Semiconducting and luminescent materials are used as the materials for active solid-state radiation detectors that are known as semiconductor detectors and scintillators
I will focus on storage phosphor materials for passive dosimetric detectors and their application to ionizing radiation monitoring

Summary

Introduction

Ionizing radiation, such as alpha-rays (helium nucleus), beta-rays (electron), X-rays and gamma-rays (electromagnetic wave), and heavy ions, has been used for many industrial and scientific purposes. When the phosphors are exposed to ionizing radiation with energy higher than that of the band gap of the phosphors, electrons in the valence band are excited to the conduction band to create electron-hole pairs in the phosphors This process is called the “energy conversion process”. Some electrons not trapped at localized centers (e.g., lattice defects and impurities) can recombine with holes to emit photons This is called the “luminescence process”, which is sometimes called scintillation. If the lattice defects and impurities, which create the localized centers, exist in phosphors, some thermalized electrons are captured at the localized centers (trapped centers) to make it to emission centers These trapped electrons in the phosphors are metastable and they can be re-excited by external stimulation with visible and/or infrared light, recombined with trapped holes to emit photons. This relationship has recently been confirmed experimentally,(6) and it is one of the important approaches to understanding the luminescence properties induced by phosphor materials exposed to ionizing radiation

Photostimulable Storage Phosphor Materials for OSL Dosimeters

Alkali-halide and alkali-earth halide storage phosphor materials

II-VI Compounds

Oxide storage phosphor materials

Other storage phosphor materials

Storage Phosphor Materials for RPL Dosimeters

Summary