Incorporation of an electro-optic ion detector into an improved plasma-source mass spectrograph

Throughout the history of mass spectrometry, array detectors have been used to conduct simultaneous and continuous mass-spectrographic studies. The benefits of acquiring multichannel data through the use of an array detector are well known and include greater duty cycle, improved precision through ratioing and internal-standardization techniques, and better quantitative analysis of fast signal transients. Because of these benefits, numerous types of array-detector-based instrumentation have been developed, including optical and mass spectrometers. Presented here is the improved performance of a plasma-source Mattauch-Herzog mass spectrograph fitted with a multichannel electro-optic ion detector. A glow-discharge source is used for all measurements. Previously reported array-detector-based data for this mass spectrograph were severely limited in quality and featured extremely poor peak shapes and resolution. Several figures of merit relevant to array detectors will be presented, including sensitivity, resolution, peak shape, and abundance sensitivity, all of which have been significantly improved. Remaining negative aspects of the array-detector performance include susceptibility to a magnetic field and the absence of uniform sensitivity across the array surface.