摘要 |
A collimator for producing an array of non-overlapping parallel microbeams of radiation of adjustable width, from a single wide beam of radiation. The invention comprises two grid assemblies arranged in juxtaposition with each other, each comprising a number of alternating parallel leaves of contrasting X-ray permeability. Each leaf of one grid assembly is of substantially the same thickness as the corresponding leaf of the other grid assembly such that passage of a wide beam of radiation through the grid assemblies results in microbeams of radiation. By offsetting the two grid assemblies slightly, the width of the microbeams may be altered. A housing apparatus is provided to ensure the leaves within one grid assembly remain parallel to one another, and that the leaves of one grid assembly remain parallel to those of the other. A micrometer adjustment apparatus allows precise control of the position of one grid assembly in relation to the other.
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