Particle Accelerators
What are particle accelerators used for?
A particle accelerator is a device that uses electric fields to propel electrically charged particles in a vacuum, which approach the speed of light, towards each other and collide. The result hopefully being that the kinetic energy in the particles and other energy converted into subatomic particles or various types of nuclear radiation.
There is more than one type of particle accelerator; they come in two basic types:
• Linear
• Circular
Linear Accelerators
The linear accelerator, or linac, uses microwave technology to accelerate electrons in a part of the accelerator called the "wave guide". Particles pass through a line of hollow metal tubes enclosed in an evacuated cylinder. Within a hollow conductor there is no electric field so a charged particle travels at constant speed inside each of the tubes. Between one tube and the next there is a potential difference which varies in size and direction as an AC voltage is applied to the series of tubes. Bunches of charged particles are accelerated from tube to tube, moving with the voltage wave as it travels along the linac.
The largest linac in the world, at Stanford University, is 3.2km long. It is capable of accelerating electrons to an energy of 50 GeV. Stanford’s linac is designed to collide two beams of particles, accelerated in turn by the linac and temporarily kept in storage rings.
The two most important problems in the linac design are the accelerator cell voltage flatness and the transverse mode impedance of the cell.
Disadvantages
• The device length limits the locations where one may be placed.
• A great number of driver devices and their associated power supplies is required, increasing the construction and maintenance expense of this portion.
• If the walls of the accelerating cavities are made of normally conducting material and the accelerating fields are large, the wall resistivity converts electric energy into heat quickly.
A particle accelerator is a device that uses electric fields to propel electrically charged particles in a vacuum, which approach the speed of light, towards each other and collide. The result hopefully being that the kinetic energy in the particles and other energy converted into subatomic particles or various types of nuclear radiation.
There is more than one type of particle accelerator; they come in two basic types:
• Linear
• Circular
Linear Accelerators
The linear accelerator, or linac, uses microwave technology to accelerate electrons in a part of the accelerator called the "wave guide". Particles pass through a line of hollow metal tubes enclosed in an evacuated cylinder. Within a hollow conductor there is no electric field so a charged particle travels at constant speed inside each of the tubes. Between one tube and the next there is a potential difference which varies in size and direction as an AC voltage is applied to the series of tubes. Bunches of charged particles are accelerated from tube to tube, moving with the voltage wave as it travels along the linac.
The largest linac in the world, at Stanford University, is 3.2km long. It is capable of accelerating electrons to an energy of 50 GeV. Stanford’s linac is designed to collide two beams of particles, accelerated in turn by the linac and temporarily kept in storage rings.
The two most important problems in the linac design are the accelerator cell voltage flatness and the transverse mode impedance of the cell.
Disadvantages
• The device length limits the locations where one may be placed.
• A great number of driver devices and their associated power supplies is required, increasing the construction and maintenance expense of this portion.
• If the walls of the accelerating cavities are made of normally conducting material and the accelerating fields are large, the wall resistivity converts electric energy into heat quickly.