Phosphors for Radiation Detectors

1Ionizing Radiation Induced Luminescence

Takayuki Yanagida

Nara Institute of Science and Technology, Ikoma, Japan

1.1 Introduction

Ionizing radiation was discovered more than one hundred years ago [1]. Ionizing radiation is defined as high energy quanta that ionize materials. For some years, the physical properties, and the uses and harmful effects of ionizing radiation, have been widely recognized. A typical property is its high penetration of materials, especially with high energy photons such as X‐ and γ‐rays. Such properties makes it possible for us to investigate the inside of materials, including the human body, without damaging any of the internal structures. On the other hand, if the human body absorbs too much ionizing radiation, the radiation can cause harm such as a cancer. In order to merit the use of ionizing radiation, control of the amount and energy generated is necessary, for which accurate detection techniques are required. Ionizing radiation is invisible and odorless, and in order to detect it, we must first convert it into something which we can easily access. In most cases, we can use various tools to convert ionizing radiation into a current. From this current, we can easily gain the information desired by using common electronics. Here, the tools used to convert ionizing radiation into recognizable information are known as radiation detectors.

Figure 1.1 illustrates the classification of typical ionizing radiation detectors. Mainly, there are two types ...