四極子形質量分析計のイオン源グリッド表面から放出された電子励起脱離イオン：脱離イオン種と圧力依存性

抄録

  The pressure dependence of the electron stimulated desorption (ESD) ions were investigated by the quadrupole mass spectrometer with a Bessel-box type energy analyzer. The mass spectra of the ESD ions were measured under introduction of H₂O, CO, O₂ and CO₂. The ESD ion peaks for those gasses were observed at O⁺ (m/z=16). The mass spectra of the gas phase ions were also measured and compared with those of ESD ions during the pumping down process. The origin of the main species in ESD ions, O⁺, was the adsorbed H₂O on the grid surfaces.