Anodic aluminum oxide microchannel plates

A new material for microchannel plates (MCP) is proposed – anodic aluminum oxide. Microchannel plates made of this material may be much cheaper than with conventional lead glass MCP. Also a significantly smaller channel diameter (up to 70 nm) is easily achievable, which means better spatial resolution and the possibility to operate in strong magnetic fields. Methods and means are developed for overcoming two main obstacles on the way to anodic aluminum oxide MCP – low conductivity of aluminum oxide and too large a ratio of channel length versus diameter. Treating aluminum oxide with lead allowed to increase the conductivity by several orders of magnitude. Directional etching allows to produce etched channels with a diameter of 2.5 μm and a length of 65 μm. Microchannel structures are produced with such channels, and electronic microscope photographs are taken of them. On those photographs one can see the spatial structure of the channels. The electrical properties of these MCP, treated with lead, were investigated using the DC method. Excess of secondary current with respect to the input beam current was observed, which can be explained as a result of avalanche electron multiplication in the channels.