An ion analyzer for the lunar surface with E-parallel-B

A modern diagnostic tool with significant heritage in the plasma fusion community is the E-parallel-B analyzer. This instrument is capable of analyzing the charge-to-mass ratio and momentum of individual particles. Each ion passing through a region with parallel E and B fields is deflected to a unique location on a 2D target according to its energy and mass. Energy and mass spectra can then be recorded using a 2D sensing technique; for example, a microchannel plate backed by a cross-delay-line (XDL) readout. The E-parallel-B design has the additional advantage of being physically compact and requiring modest field magnitudes, with electric fields on the order of a few kV/m and magnetic fields of tens to hundreds of Gauss, neither of which require exotic construction or heavy components.