Patent ID: 8866071
Filing Date: 2014-10-21
Classification: G01T

Abstract:
1. An ion detector for detecting positive ions and negative ions, comprising: a housing provided with an ion entrance to make the positive ions and the negative ions enter; a conversion dynode which is disposed in the housing and to which a negative potential is applied; a scintillator which is disposed in the housing and has an electron incident surface which is opposed to the conversion dynode and into which secondary electrons emitted from the conversion dynode are made incident; a conductive layer which is formed on the electron incident surface and to which a positive potential is applied, wherein the conductive layer is film-like; a photodetector which detects light emitted by the scintillator in response to incidence of the secondary electrons; a first mesh that is disposed in the housing at a position inside of the ion entrance, wherein potentials are applied to the first mesh depending on the polarity of the ions to be detected; and a second mesh which is disposed in the housing at a position opposite the ion entrance, wherein the mesh is grounded; wherein the photodetector is a photomultiplier tube, wherein the housing is penetrated by a light guide having a one end to which the scintillator is connected and which is disposed inside of the housing, and an other end to which the photomultiplier is connected and which is disposed outside of the housing, and wherein, when negative ions are detected, the conductive layer emits positive ions toward the conversion dynode in response to the negative ion collisions, and transmits the secondary electrons emitted from the conversion dynode so as to be made incident into the electron incident surface.