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:
Feb. 05, 2013
Filed:
Dec. 02, 2011
Junichi Taniguchi, Kyoto, JP;
Junichi Taniguchi, Kyoto, JP;
Shimadzu Corporation, Kyoto, JP;
Abstract
A technique for improving the mass-resolving power of an ion trap time-of-flight mass spectrometer is provided. At the final stage of a cooling process before the ejection of ions from an ion trap, the frequency of a rectangular-wave voltage applied to a ring electrode of the ion trap is increased for a few to several cycles. This operation reduces the confining potential depth of the ion trap and decelerates the captured ions. The turn-around time of the ions is shortened when the rectangular-wave voltage is halted and an accelerating electric field is created. Thus, the variation in the time of flight of the ions with the same mass-to-charge ratio is reduced. The time for increasing the frequency is determined so that a spread of the ions because of the depth reduction of the confining potential will fall within the range that can be corrected in the time-of-flight mass spectrometer.