| 摘要 |
PROBLEM TO BE SOLVED: To provide an ion trap which suppresses spectral noise and reduces baseline offsets and loss of spectral resolution even at higher pressure.SOLUTION: An ion trap includes: an electrode structure which includes a first and a second opposed mirror electrodes 6, 7 and a central lens 3 between the mirror electrodes 6, 7 and produces an electrostatic potential in which ions are confined to trajectories at natural oscillation frequencies, the confining potential being anharmonic. The ion trap also includes an AC excitation source 21 having an excitation frequency f that excites confined ions at a frequency of about twice the natural oscillation frequency of the ions, the AC excitation frequency source preferably being connected to the central lens 3. |
