MEANS FOR ACHIEVING UNIFORMITY OF EMISSION OF A LARGE AREA ELECTRON SOURCE

摘要

The invention pertains to electron exposure equipment useful for exposing, treating and processing coatings and other materials by a cold cathode gas discharge electron source having a broad uniform emitting area. The apparatus has a vacuum chamber; a large surface area cathode in the vacuum chamber and means for applying a negative voltage to the cathode and causing the cathode to issue electrons toward a target in the vacuum chamber. An anode is positioned between the cathode and the target. The anode is formed of an electrically conductive grid having an array of apertures therethrough extending from a center of the grid to an edge of the grid. In one embodiment the apertures have a progressively increasing area from the center of the grid to the edge of the grid. In another embodiment the anode has a progressively decreasing thickness from the center of the grid to the edge of the grid. In yet another embodiment the anode has both progressively increasing area from the center of the grid to the edge of the grid. A voltage is applied to the anode which is positive relative to the voltage applied to the cathode.