2011 年 10 巻 1 号 p. 14-22
Radiation sources were fabricated from potassium chloride chemicals that contained naturally occurring potassium-40 radioisotopes, and applied to training new workers in laboratory measurements in courses on protection against exposure to radiation at the National Institute for Fusion Science. The training involved four measurements of radiation, that to evaluate background radiation and three to assess the dependence on time, distance, and shielding effects. The counts of radiation emitted by the potassium chloride radiation sources were measured with a Geiger-Muller (GM) survey meter. Although data obtained in the training varied somewhat depending on the students, they could evaluate the level of natural radiation and understand the principles of protection against exposure to radiation. It was concluded that radiation sources fabricated from potassium chloride chemicals are convenient educational tools for illustrating naturally existing radiation and radioisotopes, and they enabled better comprehension of the principles of protection against exposure to radiation.
