Patent ID: 6633041
Filing Date: 2003-10-14
Classification: H01J

Abstract:
A method for analyzing the mass of a material sample, said method comprising the steps of:(a) providing a low voltage field emission array, said array comprising a plurality of emissions tips and emissions gates; (b) applying an electrical potential difference between said plurality of emission tips and said emission gates, said potential difference sufficient to initiate quantum tunneling at said emission tips thereby generating a flux of electrons generating an electron flux; (c) directing said electron flux into an acceleration tube and thence into an ionization region, wherein said acceleration tube has a potential sufficient to prevent electrons emitted from said emission tips from shorting to said emission gates; (d) introducing molecules from an analyte sample into said ionization region wherein collisions between said flux of electrons and said molecules result in dissociation of at least some of said analyte sample molecules; (e) directing at least some of said dissociated molecules into a mass filter, said mass filter capable of sequentially selecting dissociated molecules having a specific charge-to-mass ratio thereby permitting only said selected dissociated molecules to pass into a detector means; and (f) scanning a specific charge-to-mass ratio or across a range of charge-to-mass ratios.