略語大辞典 [Phys] 22 R Roentgen レントゲン. 放射線照射線量(単位). Roentgen; a unit of irradiation; e.g. of x-ray; ref. 1 R = 2.58×10-3 Ci・kg-1; ref. R/hour, R/week; [Phys:Med]. 丸善「略語大辞典」JLogosID : 11857306