Helium Detection via Field Ionization from Carbon Nanotubes

Abstract

A novel, high-efficiency detector for neutral atoms such as helium is described. The design uses multiwalled carbon nanotubes (MWNTs), grown by chemical vapor deposition on a steel support wire. Application of a positive bias to the MWNTs generates electric fields sufficient to field-ionize passing gas-phase atoms. Under ultrahigh vacuum conditions, the detector was demonstrated to be capable of ionising and detecting even helium gas, the element with the highest ionization potential.