The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 21, 1995
Filed:
May. 28, 1993
Vladimir M Doroshenko, Baltimore, MD (US);
Robert J Cotter, Baltimore, MD (US);
The Johns Hopkins University, Baltimore, MD (US);
Abstract
A method and apparatus for trapping ions in an ion trap having a ring electrode and a plurality of end-cap electrodes. Ions are introduced into a ion trap cavity of the ion trap from an external source or by desorption of a substance in the ion trap cavity. In a first embodiment, as the ions are introduced in the ion trap cavity, the amplitude of an RF voltage being applied to the ring electrode is gradually increased to trap the ions in the ion trap cavity. In a second embodiment, as the ions are introduced in the ion trap cavity, a retarding voltage is applied to the end-caps to reduce the initial kinetic energy of the ions. In a third embodiment, as the ions are introduced in the ion trap cavity from a probe tip inserted in the cavity, a retarding voltage is applied to the probe tip.