Consider the simple mass spectrometer show in Figure 3. A single positive ion (missing 1 electron) is emitted from a source and accelerated by an emf toward a detector that uses a uniform magnetic field to steer the particle into a detection screen, where its position is measured. Assume that all of the parameters shown in the figure can be measured and are known. 1.

3 X X X X X X X X X X X X X X X X X X X 0 = 1 X X X X X - - - X XI X X X X X X XI n X X X X X X