Mass spectrograph
From Free net encyclopedia
A mass spectrograph is used to measure the masses of ions, or to separate ions of different masses. In one design for such an instrument, ions with mass m and charge q are accelerated through a potential difference 'V'. They then enter a uniform magnetic field that is perpendicular to their velocity and are deflected in a semicircular path of radius 'R'. A detector measures where the ions complete the semicircle and from this it is easy to calculate the mass 'm'.