RA post re Ken Long's MICE Spokesperson position

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Neutrinos are three different but related particles; their ability to turn into each other has given physicists their first glimpse of the physics which they know must lie beyond the Standard Model. Investigation of the physics which underlies their properties will: deepen our understanding of how the Universe developed after the Big Bang; how the current asymmetry between matter and anti-matter developed from a situation where they were created in equal amounts in the Big Bang; and help us to understand what happens when a supernova explodes showering the cosmos with the heavy elements necessary for planets and life itself to form. In order to understand their properties, we must build an accelerator capable of creating neutrinos in immense numbers. They must have energy between well-defined limits and the mixture of different types must be very precisely known. Such a facility, known as the Neutrino Factory, would be revolutionary and to build one is challenging, both from the point of view of the particle detectors that must be built, and the engineering problems that must be overcome. This programme needs a worldwide collaboration and it is one in which physicists and engineers from the UK are playing a leading role.Neutrinos are created from a beam of muons and the muons themselves are produced from the decay of pions produced by the collision of protons with a metal target. The muon beam produced in this way is large and highly divergent. To make an intense beam of neutrinos requires that the size and divergence of the beam must be reduced. The resulting beam can be accelerated and stored such that when the muons decay an intense beam of high-energy neutrinos is produced. The muons only live for 2.2 microseconds when at rest, and even when they are accelerated and their lifetime is extended by the effect of relativity, there is little time to manipulate them so that they can be accelerated efficiently. The international Muon Ionization Cooling Experiment (MICE) collaboration is constructing a section of accelerator that has been designed to demonstrate that the size of the muon beam an be reduced efficiently.MICE is under construction at the Rutherford Appleton Laboratory in Oxfordshire. A beam of muons is created by the ISIS accelerator. Muons pass one by one through the experiment. First their position and momentum is measured in a spectrometer. Then, the muons pass through a vessel filled with liquid hydrogen, where they loose energy by ionising the hydrogen molecules. A short accelerator section restores the energy, accelerating the particles along the beam direction. The result of thus process is to reduce the random sideways motion of the muons, thereby "cooling" the beam; the system which performs the cooling is known as the cooling cell.The first stage was to build a system capable of producing a muon beam whose size and divergence could be adjusted before it enters the cooling channel. This has been completed. The second stage is to finish construction of the cooling channel itself and to provide a system to measure very accurately the position and momentum of each muon before and after it has passed through the cooling channel. By looking at many muons produced in many different conditions, it will be possible to determine how much cooling has been produced by the channel. This experiment which is pushing the boundaries of what is possible with materials, magnets and cooling technologies, is a collaboration between particle physicists and accelerator physicists and will demonstrate the UK's ability to host an experiment at the forefront of science and engineering.