[O-08] Poster presentations by senior high school students

[O08-P17] The Difference in Biotite Granite Amount of Radiation Between the ingredients

*Akari Hagiwara¹ (1.Yokohama Science Frontier High School)

Keywords:Rock, Radiation, Granite

Biotite granite is one of the popular rocks that have radioactive substances. The reason for gamma-ray emission is Kalium, uranium, and thorium. I think that I can learn about environmental radiation so I started to research. I set up the hypothesis that the reason for the difference in biotite granite amount of radiation is rock composition. I measured gamma rays, observed rock flakes, and detected the energy spectrum. As a result, the 6-biotite granite from America is emitting gamma rays than the 7-biotite granite from Hyogo. And the reason for this difference in the amount of radiation thought the difference in the amount of potassium feldspar, quartz, and plagioclase. However, a previous study said quartz that 6-biotite has fewer emissions of gamma rays. This study is in contradiction with the result that 6-biotite emits gamma rays more. This contradiction is seen in the result of 7-biotite. So, the rock composition has no relation to the number of gamma rays. Farther the reason for the difference in biotite granite amount of radiation thought amounts of the substance thorium series and uranium series. In conclusion, the reason for the difference in the biotite granite amount of radiation is the amount of radioactive material, not rock composition.