An electrostatic linear ion trap has first and second axially aligned ion mirrors separated by a charge detection cylinder and first and second nozzles, all axially aligned with each other. Electric fields are selectively established within the first and second ion mirrors in a manner which causes an ion in the trap to oscillate back and forth through the charge detection cylinder between the first and second ion mirrors. The first and second nozzles are configured to reduce noise in a charge detection signal related to charges induced on the charge detection cylinder due to oscillation of the ion back and forth through the charge detection cylinder between the first and second ion mirrors.

An electrostatic linear ion trap has first and second axially aligned ion mirrors separated by a charge detection cylinder and first and second nozzles, all axially aligned with each other. Electric fields are selectively established within the first and second ion mirrors in a manner which causes an ion in the trap to oscillate back and forth through the charge detection cylinder between the first and second ion mirrors. The first and second nozzles are configured to reduce noise in a charge detection signal related to charges induced on the charge detection cylinder due to oscillation of the ion back and forth through the charge detection cylinder between the first and second ion mirrors.