This project addresses improvements in microchannel plate (MCP) long term gain stability through reduction of elimination of mechanisms causing irreversible gain loss. Improvements in operational lifetime will result. MCP gain instability can be categorized into short term and long term losses. The short term instability is caused by adsorption and desorption of gas molecules loosely bound onto microchannel walls which can be eliminated by initial outgassing and stabliziation procedures. Long term gain instability is more serious and is irreversible. It is a direct function of accumulated output charge. Several unconfirmed mechanisms have been postulated as causing the long term loss. These mechanisms reduce to a loss in the secondary electron emission yield, and/or a change in the channel wall conductivity. Data exists on the change in secondary yield, but not on the conductivity change. This work will measure conductivity change with prolonged MCP operation and will determine the relative importance of this change and the secondary yield change in the gain degradation process by performing a computer simulation of MCP gain behavior. This will lead to the testing of process changes in phase ii to minimize or eliminate long term mcp gain loss due to aging.
