| 摘要 |
Gaseous ions trapped within an analyzer cell of an ion cyclotron resonance mass spectrometer are excited into resonance by a swept radio-frequency electric field having an envelope of trapezoidal shape. The envelope includes an onset region which ramps linearly from a zero level to a non-zero constant-amplitude level, a constant-amplitude region having the non-zero constant-amplitude level, and a termination region which ramps linearly from the constant-amplitude level to the zero level. The field has a generally constant-amplitude power spectrum and imparts relatively uniform energy to ions having natural cyclotron frequencies of interest. |
