Abstract
(1) The reference between tube voltage and ratio of scatter (=Scatter dose/Incident dose) was investigated about yarious angles of scatter. Putting the ratio proportional to (kV)^n, n was obtained as 3.0〜3.5,according to the difference of quality with the scatter angle. From this result, onepcan calculate the scatter dose at any point. (2) The influence of the BaSO_4 "Brei" to quantity and quality of scatter dose was surveyed. The quantity of scatter dose was very small, and the hardness was reduced, when the Brei was taken. The discussion was offered about these results.
