| 摘要 |
One embodiment of the present invention provides a movable mask assembly capable of reducing the power of a beam and finely controlling the size of the beam. The movable mask assembly according to one embodiment of the present invention includes a pair of mask parts which are successively arranged in an x axis direction in which light travels in front of an optical device in a beam particle accelerator line, are separated in the x axis direction with strokes which are set in y and z axis directions, and control the power and size of the beam. |
