title: Halo ion trap mass spectrometer.
abstract: We describe a novel radio frequency ion trap mass analyzer based on toroidal trapping geometry and microfabrication technology. The device, called the halo ion trap, consists of two parallel ceramic plates, the facing surfaces of which are imprinted with sets of concentric ring electrodes. Radii of the imprinted rings range from 5 to 12 mm, and the spacing between the plates is 4 mm. Unlike conventional ion traps, in which hyperbolic metal electrodes establish equipotential boundary conditions, electric fields in the halo ion trap are established by applying different radio frequency potentials to each ring. The potential on each ring can be independently optimized to provide the best trapping field. The halo ion trap features an open structure, allowing easy access for in situ ionization. The toroidal geometry provides a large trapping and analyzing volume, increasing the number of ions that can be stored and reducing the effects of space-charge on mass analysis. Preliminary mass spectra show resolution (m/Deltam) of 60-75 when the trap is operated at 1.9 MHz and 500 Vp-p.
authors.affiliation: Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84602, USA. austin@chem.byu.edu
authors.forename: Daniel E
authors.initials: DE
authors.lastname: Austin
authors.forename: Miao
authors.initials: M
authors.lastname: Wang
authors.forename: Samuel E
authors.initials: SE
authors.lastname: Tolley
authors.forename: Jeffrey D
authors.initials: JD
authors.lastname: Maas
authors.forename: Aaron R
authors.initials: AR
authors.lastname: Hawkins
authors.forename: Alan L
authors.initials: AL
authors.lastname: Rockwood
authors.forename: H Dennis
authors.initials: HD
authors.lastname: Tolley
authors.forename: Edgar D
authors.initials: ED
authors.lastname: Lee
authors.forename: Milton L
authors.initials: ML
authors.lastname: Lee