Time aberrations of uniform fields: An improved reflectron mass spectrometer for an atomhyphen;probe fieldhyphen;ion microscope

摘要

The mass resolution of the atomhyphen;probe fieldhyphen;ion microscope is limited by the time resolution of the ionhyphen;separating spectrometer. Time aberrations of uniform fields are investigated in general in order to characterize the optimal performance of highhyphen;transmission, highhyphen;mass resolution, multistage reflectron lenses. Correction of higher order time aberrations greatly improves the mass resolution. For an ion beam with an energy distributed uniformly about some nominal energy,E0plusmn;dE, mass resolutions (base width) ofm/dm=848, 1344, 2151, 3571 can be achieved for singlehyphen;, doublehyphen;, triplehyphen; and quadruplehyphen;stage reflectron mass spectrometers whendE=0.1E0. A unique design example employing both secondhyphen; and thirdhyphen;order time correction is given for an atomhyphen;probe fieldhyphen;ion microscope.