The limitations of the cyclotron are listed below.
- The energy to which particles can be accelerated in a cyclotron is limited due to the variation of mass with velocity.
- Uncharged particles cannot be accelerated by a cyclotron.
- Only charged particles like protons, deuterons and alpha particles can be accelerated by the cyclotron and electron cannot be accelerated, because the mass of electron is very small and a small increase in energy of electron makes it move with very high speed and as a result the electrons go quickly out of step with oscillating electric field.
- The energy limitation of the normal, fixed frequency cyclotron can be removed and the ions accelerated indefinitely if the applied frequency is varied to match exactly the ion rotation frequency.