title: Improving the quality of the ion beam exiting a quadrupole ion guide.
abstract: The effect of fringing fields on the divergence of the ion beam exiting an RF quadrupole ion guide was studied using a computer simulation. It was shown that reducing the strength of the RF field towards the ion guide exit reduces ion beam divergence. Further improvement was demonstrated when creating a DC gradient towards the exit. The results of the numerical simulation were verified experimentally using a time-of-flight (TOF) mass analyzer with orthogonal acceleration. Decreasing the ion beam divergence resulted in considerably improved mass resolution of the instrument.
authors.affiliation: MassTech, Inc., Columbia, Maryland, USA. bberkout@apmaldi.com
authors.forename: Vadym D
authors.initials: VD
authors.lastname: Berkout
authors.forename: Vladimir M
authors.initials: VM
authors.lastname: Doroshenko
mesh_terms: D017076:Computer-Aided Design; D055590:Electromagnetic Phenomena / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007477:Ions; D011846:Radio Waves; D021241:Spectrometry, Mass, Electrospray Ionization / Q000295:instrumentation* / Q000379:methods
chemical_list: D007477:Ions