Patent ID: 11862448
Assignee: THE TRUSTEES OF INDIANA UNIVERSITY
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H | IPC H

Claim 0:
1. A charge detection mass spectrometer (CDMS), comprising:
an ion source configured to generate ions from a sample,
a mass spectrometer configured to separate the generated ions as a function of ion mass-to-charge ratio,
an electrostatic linear ion trap (ELIT) having a charge detection cylinder disposed between first and second ion mirrors, wherein ions exiting the mass spectrometer are supplied to the ELIT,
a charge generator for generating free charges,
a field free region between the charge generator and the charge detection cylinder, and
a processor configured to control operation of the first and second ion mirrors to trap at least one ion from the source of ions therein, and to thereafter cause the trapped at least one ion to oscillate back and forth between the first and second ion mirrors each time passing through the charge detection cylinder and inducing at least one corresponding charge thereon,
and wherein the processor is configured to control the charge generator, with no ions in the charge detection cylinder, to generate a target number of free charges and cause the target number of free charges to travel across the field-free region and into contact with the charge detection cylinder to deposit the target number of free charges thereon and thereby calibrate or reset the charge detection cylinder to a corresponding target charge level.