Question

What are the different types of cyclotrons?

Answer 1

Cyclotron:

1. A type of compact particle accelerator that produces radioactive isotopes that can be used for imaging procedures is called a cyclotron.
2. It is a machine that accelerates charged particles or ions to high energies. It was invented to investigate the nuclear structure by E.O Lawrence and M.S Livingston in 1934.
3. Both electric and magnetic fields are used in the cyclotron to increase the energy of the charged particles. As both the fields are perpendicular to each other, they are called cross fields.
4. In a cyclotron, charged particles accelerate outwards from the center along a spiral path. These particles are held to a spiral trajectory by a static magnetic field and accelerated by a rapidly varying electric field.

An illustrative diagram of a cyclotron is shown below.

Types of cyclotron:

There are two types of cyclotrons, namely, synchrocyclotrons and isochronous cyclotrons.

Synchrocyclotron:

1. A modified cyclotron that obtains higher energy for charged particles by correcting for the mass change that the particles encounter as their velocity increases are called a synchrocyclotron.
2. In this type of particle accelerator, the particles are accelerated in a ring of constant radius.
3. The drawback of this type of particle accelerator is that it provides the particles in bunches on the target with a few seconds of delay in between. This is due to magnetic field adjustment because of the constant curvature of the ring as the particle’s momentum increases during acceleration.

Isochronous cyclotrons:

1. It is an alternative to the synchrocyclotron. As stated above that in synchrocyclotrons, the output beams come with a short gap. To avoid this short gap and get a continuous delivery of beam/particles, the use of isochronous cyclotrons is necessary.
2. In this structure, the magnetic poles are designed in such a way that the field’s frequency is constant for all particles. This way, all the particles get the acceleration in the isochronous time intervals.
3. The main disadvantage of this cyclotron is the size of the magnets which are large and costly. Though the output is continuous but getting the high magnetic field values at the outer edge is a bit difficult.