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US 6,255,648 B1Granted
Programmed electron flux
AssigneeApplied Automation, Inc.
InventorsDuane P. Littlejohn, Robert W. Arnold
Life of this patent
Estimating the term…
Abstract
A quantity of electrons that will be used in the ionization event in an FTICR MS is preprogrammed. When the number of electrons produced reaches that number, the electron beam is turned off. This approach assures that the same number of electrons are used for every measurement and eliminates the variations due to fundamental characteristics of the electron sourcere and the variations in temperature due to changing ambient conditions.
Claims12
A mass spectrometer comprising:
- (a). a FTICR mass spectrometer with an ionization region;
- (b). an electron source;
- (c). an electron collector opposite said electron source;
- (d). a power source having an output signal with an amplitude representative of the predetermined total number of electrons to be produced by said electron source during an ionization event in said mass spectrometer;
- and
- (e). a circuit connected to said electron collector for determining when said electron source has produced said predetermined total number of electrons and generating a signal representative thereof for ensuring that a same number of electrons are used in each measurement of said mass spectrometer.
3 more elements
Dependencies are inferred from the claim text.