放ほう射しゃ線せん物ぶつ理り学がくほうしゃせんぶつりがくMeanings1nounradiation physicsTechnical field of study dealing with the properties and effects of ionizing radiation.彼かれは大だい学がくで放ほう射しゃ線せん物ぶつ理り学がくを専せん攻こうしている。He is majoring in radiation physics at university.