Mass Spectroscope
Mass Spectroscope, an instrument used to measure the mass of atoms and molecules. Many studies of the structure of the atom have been made with this instrument. The mass spectroscope sorts out atoms and molecules according to their masses. It does this in the same general way that an optical spectroscope separates light into its various wavelengths. However, a magnetic field is used instead of a prism.
A typical mass spectroscope contains a vacuum chamber into which the atoms to be studied are fed at a constant rate. A stream of electrons converts the atoms into ions. The ions are then accelerated and aimed by passing them through tiny slits in electrically charged plates. From the plates, the ions travel through a magnetic field, which deflects them. The mass of the ions can be computed from the amount of deflection.
A mass spectrometer is an instrument in which the mass of the ions is registered by an electrical detector. In a mass spectrograph, the ions fall onto a photographic plate.
The first mass spectroscope was developed by Sir Joseph John Thomson, an English physicist, in 1912.