Patent ID: 7176455

Claim:
An apparatus for analyzing chemical species, comprising: (a) an ion source for producing ions from a sample substance; (b) at least two vacuum stages, each of said vacuum stages having means for pumping away gas to produce a partial vacuum, wherein the first of said vacuum stages is in communication with said ion source such that said ions can move from said ion source into said first of said vacuum stages; and wherein said vacuum stages are in communication with each other such that said ions can move through a sequence of said vacuum stages; (c) a Time-of-Flight mass analyzer having a pulsing region located in at least one of said vacuum stages; (d) at least one multipole ion guide positioned between said ion source and said Time-of-Flight mass analyzer, each of said at least one multipole ion guide comprising an entrance end where said ions enter said each multipole ion guide and an exit end where said ions exit said each multipole ion guide; (e) neutral background gas molecule pressure within at least a portion of at least one of said at least one multipole ion guide high enough that multiple collisions between said ions and said neutral background gas molecules occur within said portion, whereby ion kinetic energy is reduced; (f) at least one exit lens proximal to the exit end of a last one of said at least one multipole ion guide for focusing said ions from said exit end of said last multipole ion guide into said pulsing region of said Time-of-Flight mass analyzer; (g) means for applying electrical voltages to said at least one multipole ion guide; and, (h) means for applying electrical voltages to said at least one exit lens.