Simulation of the simultaneous dual‐frequency resonance excitation of ions in a linear ion trap. (15th December 2017)

• Record Type: Journal Article
• Authors: Xu, Chongsheng; Xu, Fuxing; Konenkov, N. V.; Ding, Chuan‐Fan
• Is Part Of: Journal of mass spectrometry. Volume 53:Number 2(2018)
• Page Start: 109
• Page End: 114
• Publication Date: 2017-12-15
• Subjects: dual‐frequency resonance excitation -- excitation contour -- linear ion trap -- mass resolution -- mass shift -- phase difference; Mass spectrometry -- Periodicals; 543.65
• DOI: 10.1002/jms.4043
• Languages: English
• ISSNs: 1076-5174

Abstract

Abstract: The process of ion resonance dipolar excitation in a linear ion trap by 2 ejection waveforms with close frequencies is studied. The physical mechanism of increasing the resolving power using the ion excitation is a nonlinearity of the electric radio frequency fields caused by space charge. Using 2 resonance forces with 2 close frequencies leads to the completion of 2 excitation processes. In the case of the perfect quadrupole electric field, the ion motion equations are linear, and as a result, the respondent ion ensemble is also a linear and valid superposition principle. Nevertheless, the resolution increases (20%) in the case of lack of a space charge in an operating mode with a dual‐frequency. The numerical simulations show that the mass shift is removed, and the mass resolution is increased via dual‐frequency resonance excitation when the frequency difference (approximately 2.5 kHz) is relatively small and the phase difference of 2 harmonic signals is 0 − π 3 even at a high linear ion density of up to 50 000 ions per radius field r 0 .