Patent ID: 9716001
Date: 2017-07-25
CPC Classifications: G01N,H01J

Claim:
1. A method for analyzing ionic structure, comprising the following steps of: ion trapping and exciting step: applying a radio frequency electric field on a linear ion trap to trap sample ions in the linear ion trap, the applied radio frequency electric field having high order components which are even order fields; and applying an auxiliary alternating current electric field or applying a broadband excitation electric field on the linear ion trap to cause the sample ions to be excited to a motion amplitude not exceeding the trapping ability of the linear ion trap, the motion amplitude at this moment being recorded as a primary motion amplitude (a signal collecting step: continuously feeding carrier gas into the linear ion trap and keeping a degree of vacuum in the linear ion trap to be smaller than 1.333 Pa, the sample ions being collided with the carrier gas and the motion amplitude being decreased gradually till a second moment (tt), and collecting a time domain signal of an image current generated by the sample ions during the process from the first moment (t signal processing step: analyzing the time domain signal through a time-frequency analysis method and respectively obtaining time-varying characteristic curves (C) of the motion frequencies (f) of ions having various sizes in the sample ions varied with time so as to distinguish among the ions having different sizes, each of the time-varying characteristic curves (C) indicating a corresponding relation between a motion frequency of the ion having a corresponding size and a collision cross sectional area of the ion and the carrier gas.