Charged particle energy analyzer based upon isentropic containment

摘要

Charged particles (ions or electrons) are directed into a drift tube closed off at the upstream and downstream ends by electrical grid members and having an axial magnetic field therein with a substantial radial component. The grids are pulsed to trap the charged particles in the drift tube where the radial magnetic field component mixes their axial and orbital momenta. The potential of the downstream grid is successively lowered for successively extracting particles having a successively lower energy. This analyzer is particularly useful for analyzing surface constitutents.