An enhancement of ion energy spectra resolution and sensitivity in a multigridded energy analyzer with a retarding grid potential: the variable energy analyzer (VEA)

An energy analyzer was developed that allows enhanced resolution of ion energy spectra and sensitivity. The energy analyzer is based on the principles of electrostatic multigrid ion or electron energy analyzers. Studies indicate that geometrical parameters such as grid separation, the grid transparency, and the spatial charge all influence the characteristic curve of the analyzer (typically a plot of collector current versus the retarding potential on the discriminator grid of the analyzer). Through the adjustment of these parameters, the resolution and the sensitivity of the analyzer is improved by a factor of two. It was found that there was an optimum separation distance between the two grids where the analyzer provides optimal resolution.<>