Generation of an exact three-dimensional quadrupole electric field and superposition of a homogeneous electric field in trapping-exciting mass spectrometer (TEMS)
US5283436A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 30, 1992 |
| Grant date | Feb 1, 1994 |
| Priority date | — |
| Expiry date | Jun 30, 2012 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J49/027
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An exact three-dimensional rotationally symmetric quadrupole field or an electric field of higher multipole moments can be generated by closed boundaries with continuously varied potential, especially with linearly variable potential, in the ideal case by simple cone-shaped boundaries with linearly variable potential. An example for the application of the field is storage of charged particles inside the closed boundaries. Within the same cone-shaped boundaries, a homogeneous ideal field in the direction of the symmetry axis can be superimposed. This field can be employed for excitation of the kinetic energy, for quenching, or for energy analysis of the stored charged particles. For the generation of mass spectra the mass-to-charge specific fundamental frequencies of the charged particles stored in the electrode structure are excited. The image currents induced in the electrode structure are frequency analysed (e.g. by Fourier transform).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.