2020 年 19 巻 2 号 p. 92-97
We have developed a teaching material for high school students to learn the basic properties of ionizing radiation. The teaching material simply simulates the diagnosis method in SPECT (single photon emission computed tomography), and consists of a radiation source, radiation detectors, and an opaque box as a human brain phantom. Thirty-five students participated in the experiential learning using the teaching material. Before the student experiment, the radiation source was placed in the opaque box, without showing the students where the radiation source was. The students measured the dose rates at several positions outside the opaque box. The position of the radiation source was estimated from the dose rates according to the inverse square law of ionizing radiation. This experiential learning effectively helped the students understand the basic properties of ionizing radiation.