| 摘要 |
PURPOSE:To increase a radiation source length even in a limited setting space and extend the measuring range. CONSTITUTION:A cylindrical outer sheath 15a is blocked by an upper plate 15c and a lower plate 15b to form a radiation source vessel 15, a lead 16 for preventing the leak of a radiation 7 to the part other than irradiating direction is charged in the inner part. Arranging successively in the irradiating direction, a bar radiation source 17 is provided in a hole 16a in such a manner as to be vertically movable, a bar radiation source 5 is fixed to a hole 16b, and a rotating shutter 18 is rotatably provided on a hole 16c. A motor 20 for vertically moving the bar radiation source 17 is mounted on the upper part of the radiation source vessel 15, and a cylinder 22 concentric to the bar radiation source 17, into which cylinder the insertion of the whole length of the radiation source 17 can be inserted, is mounted on the lower part of the radiation source vessel 15. |
