Mass spectroscopy

Mass spectroscopy, spectroscopic technique in which electric and magnetic fields are used to deflect moving charged particles according to their mass; employed for chemical analysis, separation, isotope determination, or finding impurities. The apparatus for obtaining a mass spectrum (i.e., a number of “lines” of distinct charge-to-mass ratio obtained from the beam of charged particles) is known as a mass spectrometer or mass spectrograph, depending on whether the lines are detected electrically or on a photographic plate. In essence, it consists of an ion source, a vacuum chamber, a deflecting field, and a collector. By altering the accelerating voltage and deflecting field, particles of a given mass can be focused to pass together through the collecting slit.

See also: Spectrometer.