| 摘要 |
<p>One virtual rod electrode (11) is constructed with a plurality of electrode plates (111,... ,118) arranged in an ion light axis direction, and four (11, 12, 13, 14) of them are disposed around the ion light axis (C) to construct a virtual quadrupole rod type ion optical element (1). A voltage applying portion alternately applies high-frequency voltages 180° out of phase with each other to the electrode plates one after the other, making a quadrupole electric field component of a high-frequency electric field formed in a space surrounded by the four virtual rod electrodes small while making a high-order multipole electric field component large. The quadrupole electric field component has a strong ion convergence and mass selectivity, while the high-order multipole electric field component has a strong ion permeability and ion acceptability. The ion transportation efficiency of an ion optical system can be totally improved by properly adjusting the ion optical characteristics thereof according to the environment wherein it is disposed and anteroposterior conditions.</p> |
