CHEMICAL METHOD TO INCREASE EXTREME-ULTRAVIOLET MICROCHANNEL-PLATE QUANTUM EFFICIENCY

The quantum detection efficiency of photon-counting microchannel-plate detector channels can be increased by a factor of 2 in the extreme ul traviolet bandpass, from 256 Angstrom to 1024 Angstrom by subjecting t he input channel plate to a chemical solution treatment. The efficienc y increase has proven to be insensitive to the exposure of laboratory atmosphere and is stable over the extracted charge lifetime equivalent of multiyear astrophysical observations. Chemically treated microchan nel plates that are overcoated with opaque photocathodes of KBr and Cs I show a factor of 2 quantum detection efficiency increase from 834 An gstrom to 1100 Angstrom in comparison with previous measurements using conventional untreated microchannel plates. (C) 1997 Optical Society of America.