The Neutrino Factory is a proposed

particle accelerator A particle accelerator is a machine that uses electromagnetic fields to propel charged particles to very high speeds and energies, and to contain them in well-defined beams. Large accelerators are used for fundamental research in particle ...

complex intended to measure in detail the properties of

neutrinos A neutrino ( ; denoted by the Greek letter ) is a fermion (an elementary particle with spin of ) that interacts only via the weak interaction and gravity. The neutrino is so named because it is electrically neutral and because its rest mass is ...

, which are extremely weakly interacting

fundamental particles In particle physics, an elementary particle or fundamental particle is a subatomic particle that is not composed of other particles. Particles currently thought to be elementary include electrons, the fundamental fermions ( quarks, leptons, a ...

that can travel in straight lines through normal matter for thousands of kilometres. Up until the 1990s, neutrinos were assumed to be massless, but experimental results from searches for solar neutrinos (those produced in the

Sun The Sun is the star at the center of the Solar System. It is a nearly perfect ball of hot plasma, heated to incandescence by nuclear fusion reactions in its core. The Sun radiates this energy mainly as light, ultraviolet, and infrared radi ...

's core) and others are inconsistent with this assumption, and thus indicate that the neutrino does have a very small mass (see

Solar neutrino problem The solar neutrino problem concerned a large discrepancy between the flux of solar neutrinos as predicted from the Sun's luminosity and as measured directly. The discrepancy was first observed in the mid-1960s and was resolved around 2002. The fl ...

Function

The Neutrino Factory will create a fairly focused beam of neutrinos at one site on the

Earth Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's surfa ...

and fire it downwards, probably in two beams emitted in different directions from a racetrack shaped underground muon storage ring, until the beams resurface at other points. One example could be a complex in the UK sending beams to Japan (see

Super-Kamiokande Super-Kamiokande (abbreviation of Super-Kamioka Neutrino Detection Experiment, also abbreviated to Super-K or SK; ja, スーパーカミオカンデ) is a Neutrino detector, neutrino observatory located Kamioka Observatory, under Mount Ikeno ...

) and

Italy Italy ( it, Italia ), officially the Italian Republic, ) or the Republic of Italy, is a country in Southern Europe. It is located in the middle of the Mediterranean Sea, and its territory largely coincides with the homonymous geographical ...

(

LNGS Laboratori Nazionali del Gran Sasso (LNGS) is the largest underground research center in the world. Situated below Gran Sasso mountain in Italy, it is well known for particle physics research by the INFN. In addition to a surface portion of the ...

). The properties of the neutrinos will be examined at the remote sites to determine how neutrinos evolve over time. This will provide information about their masses and

weak interaction In nuclear physics and particle physics, the weak interaction, which is also often called the weak force or weak nuclear force, is one of the four known fundamental interactions, with the others being electromagnetism, the strong interaction ...

properties. The project is currently in the conceptual design stage. An international "Scoping Study" was completed in 2007 and an international effort to write a design report has now begun. Many new technologies are being pioneered for this experiment, including the use of liquid metal jets as a target for pion production, under test in the , the use of Fixed Field Alternating Gradient (FFAG) accelerators, under test in the EMMA experiment, and liquid hydrogen energy reduction cavities for reducing the divergence in the muon beam during the intermediate stages.

Associated design efforts

International Design Study

The International Design Study seeks to present a design report for the Neutrino Factory that details the physics performance, schedule and costs by 2012. The study will include contributions from all regions in a combined Reference Design Report.

UK Neutrino Factory

There is a United Kingdom Neutrino Factory group.

U. S. Muon Accelerator Program

In 2010, the Muon Accelerator Program (MAP) unified the United States Department of Energy research support for Muon Colliders and Neutrino Factories. (Both projects involve producing

muons A muon ( ; from the Greek letter mu (μ) used to represent it) is an elementary particle similar to the electron, with an electric charge of −1 '' e'' and a spin of , but with a much greater mass. It is classified as a lepton. As wi ...

and holding them in a storage ring, so there was much overlap.) The

Muon Collider A Muon Collider is a proposed particle accelerator facility in its conceptual design stage that collides muon beams for precision studies of the Standard Model and for direct searches of new physics. Muons belong to the second generation of lept ...

project is even more ambitious than the Neutrino Factory. In the Muon Collider, the muons will be inserted into a very high-energy collider ring, aiming to reach higher concentrations of energy than even the Large Hadron Collider (LHC) (first collisions produced in 2010) or perhaps even the Linear Collider Collaboration (LCC) experiments (design incomplete as of 2019.)

European Neutrino Group

CERN did a design study a few years ago, before effort moved on to the LHC. Activities in

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a subcontinent of Eurasia and it is located entirel ...

continue with meetings and involvement in international experiments and collaborations.

Japanese design

This is based on an unusual type of accelerator called an Fixed Field Alternating Gradient (FFAG) that combines elements from the cyclotrons of the 1950s with modern automated magnet design processes, and new magnetic alloy radiofrequency accelerating gaps. The main advantage of these is that the magnetic fields are fixed and do not have to be synchronised to the beam in any way, yet the beam naturally moves into regions of higher field as its energy increases, allowing for very rapid acceleration without the difficulties found in very rapid-cycling synchrotrons.

References

External links

International Muon Ionization Cooling Experiment The International Muon Ionization Cooling Experiment (or MICE) is a high energy physics experiment at the Rutherford Appleton Laboratory. The experiment is a recognized CERN experiment (RE11). MICE is designed to demonstrate ionization cooling o ...

* {{neutrino detectors Particle physics facilities Neutrino observatories Proposed particle accelerators