A field-ionization neutral detector - FIND

The field ionization neutral detector FIND operates according to the following principle: Neutral atoms are attracted toward the field ionization tips since they are polarized by the electric field of the tips. The atoms are singly ionized and repelled by the positive potential of the tips toward the detector situated behind a grid at ground potential. The ions deposit in the detector their kinetic energies, typically 26 keV, corresponding to the potential difference between the ionization region and the detector. Laboratory results show that FIND can have the resolution, sensitivities and durability required to perform in situ measurements of neutral H and He fluxes in interplanetary space, cometary halos and exospheres.