  Measurements of Ion velocity distributions are one of basic goals of space
plasma studies. There is variety of ion and electron spectrometers (e.g. Wuest
et al, 2007, Young et al., 2007, Zurbuchen and Gershman, 2016, Vaisberg et al,
2016). The most frequently used ion spectrometer is top-hat analyzer (Carlson
et al., 1983) consisting of toroidal electrostatic analyzer, electrostatic
scanner and time-of-flight section with thin foil as start element and ion
pre-acceleration. We describe new energy-mass analyzer with electrostatic
scanner providing hemispheric field-of view with small aberration, toroidal
electrostatic analyzer, time-of-flight synchronizer with simple gate. It
provides desirable hemisphere scanning, wide energy range and reasonable mass
resolution. It can provide detailed measurements of the ion velocity
distribution of ion species without significant gaps to obtain reliable moments
of plasma flow. This analyzer without TOF ability can be used for measurements
of electron component. With simple electro-optics elements this analyzer can be
easily modified to many goals of plasma investigations.
