Microchannel Plate Detector Gain Decrease Through Storage Under Environmental Conditions

Open microchannel plate (MCP) detectors are widely used for the detection of particles and photons with diverse instruments, including the space flight ones. Space mission preparation and flight instruments construction commonly take a long time during which it is difficult or impossible to ensure the recommended storage conditions (inert gas atmosphere or vacuum) for MCP detectors. We have estimated the gain decrease of a flight laser ionization time-of-flight (TOF) mass spectrometer laser mass-analyzer (LASMA) utilizing an MCP detector during its storage under normal conditions (1 atm pressure, air atmosphere, room temperature, air humidity 40%–60%) for almost ten years. It was found that the detector sensitivity (i.e., gain) over the observations period decreased by 2.4–2.8 times. Such a decrease can be considered not critical for some instruments using nonposition-sensitive MCP-based detectors. The data obtained can be applied to develop requirements for flight instruments constructions, storage, and service, which could simplify some space mission preparation.