Cyclotron - History, Working, Uses, Frequency FAQs
A cyclotron is a machine used to make charged particles move very fast. In a cyclotron, the particles start from the centre and move in a spiral path. A magnetic field helps the particles move in a circular path, while an electric field gives them energy and makes them faster. Each time the particles cross the gap between the plates, they gain more energy. Cyclotrons are used in science laboratories, medical treatment, and nuclear research. By studying a cyclotron, students can understand how electric and magnetic fields affect moving charges. In this article, we will learn about the working, parts, formulas, uses, and limits of a cyclotron in a simple way.
This Story also Contains
- What is a Cyclotron?
- History Of Cyloctron
- Principle of Cyclotron
- Construction of Cyclotron
- Cyclotron Formula
- Frequency of Cyclotron
- Uses of Cyclotron
- Limitations of a Cyclotron
What is a Cyclotron?
A cyclotron is a device used to accelerate charged particles (such as protons and ions) to very high speeds using a combination of a strong magnetic field and an alternating electric field.
In a cyclotron, charged particles move in a circular spiral path and gain energy each time they cross the gap between two semicircular metal chambers called dees (D-shaped electrodes).
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History Of Cyloctron
The cyclotron was invented in 1930 by Ernest O. Lawrence, an American physicist, at the University of California, Berkeley. He developed the cyclotron to accelerate charged particles to very high energies using a magnetic field and an alternating electric field.
The first cyclotron was small and could fit on a tabletop, but later, larger and more powerful cyclotrons were built for advanced research. Ernest Lawrence was awarded the Nobel Prize in Physics in 1939 for the invention and development of the cyclotron.
Cyclotrons played an important role in the development of nuclear physics, medical research, and the production of radioactive isotopes, and they laid the foundation for modern particle accelerators.
Principle of Cyclotron
An electron beam is accelerated by a cyclotron using a high-frequency alternating current that passes between two hollow "D"-shaped sheet-metal electrodes inside a vacuum chamber.
A cylindrical space is created within the Dees with a narrow gap between them, allowing particles to move between them. Into this space are injected particles.
A static magnetic field B is applied perpendicular to the electrode plane by the electromagnet located between the poles.
Due to the Lorentz force perpendicular to the direction of motion, the magnetic field bends the path of the particle in a circle.
Multiple thousand volts of alternating voltage are applied between the diodes. As a result of the voltage, the particles accelerate due to an oscillating electric field between them.
One circuit is formed during one cycle of voltage, so the frequency of the voltage is set appropriately. Boosting the particle's cyclotron frequency is required to achieve this condition.
Construction of Cyclotron
A cyclotron consists of the following main parts:
- Dees (D-shaped chambers): Two hollow, semicircular metal boxes called dees are placed facing each other. They are kept inside a vacuum chamber.
- Vacuum Chamber: The dees are enclosed in a high vacuum so that charged particles do not collide with air molecules.
- Magnetic Field: A strong uniform magnetic field is applied perpendicular to the plane of the dees. It helps the charged particles move in a circular path.
- High Frequency Oscillator: An alternating electric field is applied across the gap between the dees to accelerate the particles.
- Ion Source: Placed at the centre, it produces charged particles (like protons).
- Deflector Plate: Used to take the accelerated particles out of the cyclotron.
Cyclotron Formula
The important formulas related to a cyclotron are:
1. Radius of circular path
$
r=\frac{m v}{q B}
$
2. Cyclotron frequency
$
f=\frac{q B}{2 \pi m}
$
3. Time period of revolution
$
T=\frac{2 \pi m}{q B}
$
4. Maximum kinetic energy
$
K=\frac{q^2 B^2 r^2}{2 m}
$
NCERT Physics Notes :
Frequency of Cyclotron
The frequency of a cyclotron is the frequency of the alternating electric field required to accelerate the charged particle.
It is given by:
$
f=\frac{q B}{2 \pi m}
$
where:
- $q=$ charge of the particle
- $B=$ magnetic field strength
- $m$ = mass of the particle
Uses of Cyclotron
- Used to accelerate charged particles to very high energies.
- Used in nuclear physics research and experiments.
- Helps in the production of radioactive isotopes.
- Used in medical science for cancer treatment (radiotherapy).
- Used for bombarding nuclei to study nuclear reactions.
- Plays an important role in particle physics research.
Limitations of a Cyclotron
- A cyclotron cannot accelerate neutral particles because they are not affected by electric and magnetic fields.
- It cannot be used to accelerate electrons due to their very small mass and relativistic effects.
- At very high speeds, the mass of the particle increases, which disturbs the resonance condition.
- Cyclotron is not suitable for accelerating particles to very high energies.
- It requires a strong and uniform magnetic field, which is difficult to maintain.
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Frequently Asked Questions (FAQs)
Radiation imaging is performed using radioactive isotopes produced by a cyclotron. Using cyclotrons, which use magnetic fields to accelerate charged particles (protons) to high energies, stable, non-radioactive isotopes are put into the cyclotron.
A cyclotron accelerates charged particles and ions to high energies. E.O. M.S. and Lawrence A nuclear structure experiment designed by Livingston in 1934. Magnetic and electric fields are used in cyclotrons to increase the energy of charged particles.
M.S. and E.O. Lawrence It was invented by Livingston for the study of nuclear structure in 1934.
The spiralling of electrons in a cylinder of vacuum generates high-frequency radio waves (microwaves). Particles are moved along a line of constant radius toward synchrocyclotron in the form of pipes, which allows them to reach greater distances than is feasible with cyclotrons and synchrocyclotron.
The use of cyclotrons as particle therapy devices can kill cancerous tumours by using ion beams that penetrate the body and damage the tissue.