Three-dimensional quadrupole mass spectrometer

摘要

A three-dimensional quadrupole mass spectrometer is suitable for preventing occurrence of a situation where the mass spectrometry cannot be conducted by an excessive existence of ions in a three-dimensional ion confining space, an amount of ions emitted from an ion source 1 is detected by a first electrode 3 of a lens, an output signal therefrom is inputted to a power supply 17 of a second electrode 4 of the lens and a focusing condition of ions caused by the lens is changed such that an amount of ions existing in the three-dimensional ion confining space does not exceed a certain level.