Electrostatic spectrograph for different ranges of simultaneously recorded energies with a discrete combined external electrode

We propose and study numerically a large-aperture electrostatic spectrograph consisting of the two coaxial electrodes, a cone-cylindrical electrode separated into several segments, and a small cylindrical electrode. The supply voltages providing sharp focusing of charged particle beams in the initial region of the spectrum for different ranges of simultaneously detected energies $E_{\operatorname{max}}/E_{\operatorname{min}}$ = (25–100) are determined. Electron- optical parameters of the spectrograph in four energy ranges are calculated, with the electrical similarity principle being used for charged particles of medium and high energies. The resolution of the spectrograph for medium and high energies, $E$ = (0.1–1)$E_{\operatorname{max}}$, is equal to (5–3) $\times$ 10$^{-3}$. For small energies, $E$ = (0.01–0.1)$E_{\operatorname{max}}$, the resolution worsens and varies within the (0.6–1.6) $\times$ 10$^{-2}$ range as the range of simultaneously recorded energies increases.