Abstract: A new mass spectrometer (10) is described in which sample molecules (26) are ionized and caused to oscillate to and fro by reflecting electric fields established between two electrodes (12, 14) in a vacuum chamber (20). A mesh electron producing electrode (16) is located between reflector electodes (12, 14) and produces electrons by secondary emission on each pass of the oscillating ions when some of those ions strike the mesh. The secondary eldctrons are detected (18) after passage through reflector electrode (12), which is alos a mesh. The frequency of oscillation of the ions depends upon their mass and from the frequency distribution of the signals from each electron production event it is possible to identify the ions of different masses. The invention allows for a much more compact spectrometer instrument compared to a Time of flight Mass Spectrometer which is less expensive than a Fourier Transform Mass emplying ion-cyclotron resonance.

Abstract: A new mass spectrometer (10) is described in which sample molecules (26) are ionized and caused to oscillate to and fro by reflecting electric fields established between two electrodes (12, 14) in a vacuum chamber (20). A mesh electron producing electrode (16) is located between reflector electodes (12, 14) and produces electrons by secondary emission on each pass of the oscillating ions when some of those ions strike the mesh. The secondary eldctrons are detected (18) after passage through reflector electrode (12), which is alos a mesh. The frequency of oscillation of the ions depends upon their mass and from the frequency distribution of the signals from each electron production event it is possible to identify the ions of different masses. The invention allows for a much more compact spectrometer instrument compared to a Time of flight Mass Spectrometer which is less expensive than a Fourier Transform Mass emplying ion-cyclotron resonance.