Ion optical evaluation of a miniature double-focusing mass spectrograph

A new miniature double-focusing mass spectrograph has been designed and constructed. The ion optical system was designed based on Mattauch-Herzog geometry. The mass spectrograph employs a focal plane detector consisting of a microchannel plate, a phosphor layer, a fiber-optic plate and a charge-coupled device. For the evaluation of the ion optics of the instrument, the energy and angular focal planes were investigated both experimentally and by simulation. Double focusing was satisfactorily achieved along a straight line over a wide mass range, and the experimental and simulated results were mutually consistent. A second-order element of the transfer matrix was also measured experimentally and proved to be in good agreement with the simulated result.