# LINAC Linear Accelerator vs Circular Accelerator Difference

This page compares LINAC(Linear Accelerator) vs circular accelerator and mentions basic difference between linear accelerator(LINAC) and circular accelerator.The merits of linear accelerator(LINAC) and circular accelerator over each other are also mentioned.

Basics: The accelerator takes a particle, speeds it up using EM fields, bashes particle into either a target or other particles. Detectors are placed around to record this event.

How Accelerator works: The accelerator works based on following principles/Laws.
➨Electrically charged objects exert forces on each other. Opposite charges attract and like charges repel.
➨ Coulomb's Law = F = -K*q1*q2/r2
➨ Newton's Law = F = m*a
➨A particle with positive or negative charge experiences a force when it is in presence of electric field. When a net force acts on an object, the object accelerates.

Accelerators in particle physics are categorized into two types viz. fixed target and colliding beams. In fixed target, a particle is shot at a fixed target. In colliding beams, two beams of particles are made to cross each other.

Further, Accelerators are of two types based on structure viz. linear and circular type as described below.

## LINAC-Linear Accelerator

Definition: The accelerator in which particle is shot like a bullet from a gun is known as linear accelerator. It is also known by the team LINAC. It follows linear path. It is used for fixed target experiments.

## Linear Accelerator for Cancer treatment

One of the major application of Linear Accelerator is for cancer treatment. It is used to treat all the parts or organs of the body. It delivers high energy X-rays to region of patient's tumor sparing surrounding normal tissue. This external beam radiation treatment helps in destroying cancer cells.

The linear accelerator here uses RF or microwave technology to accelerate electrons in part of accelerator known as waveguide. This allows electrons to collide with heavy metal in order to generate X-ray with high energy. These are shaped to conform as per tumor size of the patient as they come out of the machine. Careful considerations need to be taken care by both the radiation physicist in accordance with radiation oncologist during the treatment by this method.

## Circular Accelerator

Definition: The accelerator which is used for colliding beam experiments in which particles are extracted from ring for fixed target experiments is known as circular accelerator. It is also known bt the term Synchrotron. Large magnets are used which tweak path of particle to keep it in circular motion.

## Merits of Linear Accelerator (LINAC) over Circular Accelerator

Following are the merits (advantages) of linear accelerator over circular accelerator.
• They are easier to build.
• They do not require large magnets.
• They are less expensive compare to circular type. This is because circular accelerator need huge radii to bring particles to high energy states. This results into higher cost of constructing circular accelerator.
• Charged particle radiates away energy when it is accelerated. At high energy state, radiation loss is lesser for linear accelerator compare to circular accelerator.

## Merits of Circular Accelerator over Linear Accelerator

Following are the merits (advantages) of Circular accelerator over Linear accelerator.
• As we know particles in circular type go around many a times. Due to this, they get multiple kicks of energy each time around. Hence the circular accelerator provides very high energy particles without requiring much of length compare to linear accelerator.
• The reason of having high energy particles is due to the fact that particles go around many times resulting into many chances for the collisions at those places where particle beams are made to cross each other.