Ionization System for Charged Particle Analyzers

摘要

A sample ionization system includes at least an ionization source disposed at an ion source end of a charged particle analyzer, for selectably generating first ions in an analyzing mode of operation and second ions in a cleaning mode of operation. The first ions are one of positively and negatively charged and the second ions are the other one of positively and negatively charged. The second ions are directed through the charged particle analyzer toward a surface of an ion optic component, for at least partially neutralizing a buildup of charge caused by the first ions impinging on the surface of the at least one ion optic component.

主权项

1. A method for operating a charged particle analyzer, comprising:
during a first period of time, generating one of positively charged ions and negatively charged ions at an ion source end of the charged particle analyzer; directing the ions that are generated during the first period of time along a first ion flow path defined between the ion source end and a mass analyzer end of the charged particle analyzer, the first ion flow path including at least one ion optic component disposed between the ion source end and the mass analyzer end, some of the ions that are generated during the first period of time impinging upon a surface of the at least one ion optic component and imparting a charge thereto; providing an electric field within the charged particle analyzer during the first period of time, the electric field supporting transmission of the ions that are generated during the first period of time along the first ion flow path; generating the other one of positively charged ions and negatively charged ions during a second period of time; directing the ions that are generated during the second period of time along a second ion flow path defined between the ion source end and the surface of the at least one ion optic component, such that at least some of the ions that are generated during the second period of time impinge upon the surface of the at least one ion optic component and at least partially neutralize the charge imparted by the ions that are generated during the first period of time; and modifying the electric field at least proximate the at least one ion optic component such that a greater fraction of the ions that are generated during the second period of time, relative to a fraction of the ions that are generated during the first period of time, impinges upon the surface of the at least one ion optic component.