Particle beam cooling
Encyclopedia
To be developed as a jump page related to particle accelerators
Cooling techniques are important for the control the emittance
of particle beam
s in particle accelerator
s. Usually, these techniques take advantage, in some way, of the electric or the magnetic fields present in the fast-moving bunches of particles in the accelerator in clever ways to damp the tenancy of these particles to repel each other. It is accurate to think of these techniques as thermodynamic cooling, or the reduction of entropy
, in much the same way that a refrigerator
or an air conditioner cools its contents.
The main types of particle beam cooling are:
Cooling techniques are important for the control the emittance
Beam emittance
The beam emittance of a particle accelerator is the extent occupied by the particles of the beam in space and momentum phase space as it travels. A low emittance particle beam is a beam where the particles are confined to a small distance and have nearly the same momentum...
of particle beam
Particle beam
A particle beam is a stream of charged or neutral particles which may be directed by magnets and focused by electrostatic lenses, although they may also be self-focusing ....
s in particle accelerator
Particle accelerator
A particle accelerator is a device that uses electromagnetic fields to propel charged particles to high speeds and to contain them in well-defined beams. An ordinary CRT television set is a simple form of accelerator. There are two basic types: electrostatic and oscillating field accelerators.In...
s. Usually, these techniques take advantage, in some way, of the electric or the magnetic fields present in the fast-moving bunches of particles in the accelerator in clever ways to damp the tenancy of these particles to repel each other. It is accurate to think of these techniques as thermodynamic cooling, or the reduction of entropy
Entropy
Entropy is a thermodynamic property that can be used to determine the energy available for useful work in a thermodynamic process, such as in energy conversion devices, engines, or machines. Such devices can only be driven by convertible energy, and have a theoretical maximum efficiency when...
, in much the same way that a refrigerator
Refrigerator
A refrigerator is a common household appliance that consists of a thermally insulated compartment and a heat pump that transfers heat from the inside of the fridge to its external environment so that the inside of the fridge is cooled to a temperature below the ambient temperature of the room...
or an air conditioner cools its contents.
The main types of particle beam cooling are:
- Stochastic coolingStochastic coolingStochastic cooling is a form of particle beam cooling. It is used in some particle accelerators and storage rings to control the emittance of the particle beams in the machine. This process uses the electrical signals that the individual charged particles generate in a feedback loop to reduce the...
- Electron coolingElectron coolingElectron cooling is a process to shrink the size, divergence, and energy spread of charged particle beams without removing particles from the beam. Since the number of particles remains unchanged and the space coordinates and their derivatives are reduced, this means that the phase space occupied...