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Europe picks a neutrino machine

Posted on behalf of Devin Powell.

According to a new prioritization, the Neutrino Factory, a proposed multibillion-euro facility, is the best long-term European option for testing whether neutrinos and antineutrinos behave differently, a step towards understanding why the Universe contains primarily matter instead of antimatter.

The recommendation comes from a report, four years in the making, that looks ahead to Europe’s future in high-intensity neutrino research. Paid for by the European Commission’s Seventh Framework Programme and presented on 10 June at CERN, Europe’s largest particle physics laboratory, in Switzerland, the EUROnu project weighed the pros and cons of three candidate neutrino machines.

Costing between €4.6 billion (US$6.1 billion) and €6.5 billion, the Neutrino Factory would generate an especially intense beam of neutrinos and send them on an underground journey of about 2,000 kilometres. At the source end, probably at CERN, the neutrino beam would be created by smashing protons into a solid target, producing muons that in turn break down into neutrinos. At the receiving end, perhaps in Finland’s Pyhäsalmi mine, a 100-kilotonne detector made of iron could spot the arrival of neutrinos and detect whether the particles had ‘oscillated’ during flight, transforming from one of the three types of neutrinos to another.

This setup could measure how often neutrinos and antineutrinos change form with less error than the other two options considered by the report: Beta Beam, powered by the breakdown of ions, and Fréjus Super Beam, which would employ a water-based detector. The Neutrino Factory would be significantly more expensive, though, so its architects are exploring ways to scale it down or implement it in stages.

Whether the facility will ever be funded and built, in its entirety or in stages, remains an open question, especially in light of the CERN Council’s recent update to the European strategy for particle physics. It indicates a willingness to back large projects abroad, such as the Long-Baseline Neutrino Experiment (LBNE), which intends to send neutrinos on a 1,300-kilometre trip from Fermilab in Batavia, Illinois, to a mine in South Dakota.




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    Eugene Sittampalam said:

    [Then Fermi] delivered his verdict in a quiet, even voice. “There are two ways of doing calculations in theoretical physics”, he said. “One way, and this is the way I prefer, is to have a clear physical picture of the process that you are calculating. …”
    A meeting with Enrico Fermi, Freeman Dyson (Institute for Advanced Study, Princeton), Nature 427, 297 (2004)
    In keeping with those words of wisdom of the great physicist, kindly allow me here to present my clear physical picture of the neutrino:
    There is a misconception today that the neutrino can pass through, say, the Earth
    without even affecting a single atom (Bahcall, J. N., Neutrino Astrophysics, Cambridge University, U. K., 1989). In reality, however, the quantum that is the neutrino recoils from around the equator of its subatomic particle of origin. It is thus nuclear in origin and, therefore, will be nuclear in effect, like the gamma ray.
    But, unlike the gamma ray, though, the neutrino has a two-dimensional (broadside) and radial spread, which causes the energy quantum to drop in intensity (as the inverse square) with distance.
    he other hand, however, this wider field of influence enables the quantum to intercept much more
    atoms than would the quantum of the essentially one- dimensional (needle-like) photon.
    Since the neutrino possesses energy, it also packs momentum and transfers it successively, in a radial domino effect, to EVERY SINGLE ATOMIC NUCLEUS AND ELECTRON along its way, subtle and beyond detection though the effect may be on individual atoms, especially with distance.
    Nevertheless, in an intense stream of neutrinos, as from a supernova explosion,
    Earth detectors are now able to register an effect (Bionta, R. M. et al., Phys. Rev. Lett. 58, 1494; 1987). As nuclei and electrons of the detection medium recoil from the neutrino impact and
    successively pass on the effect, certain electrons down the line get a concentrated, or
    lensed, effect strong enough to knock them off their atoms and thereby cause
    detection. In other words, the interference of the neutrino wavefronts can, at times,
    cause a detectable effect even though generally every atom of the medium gets
    thumped without a seeming whimper.
    And, hopefully, this model of the neutrino should now help explain its seeming elusive nature with
    which it has been synonymous. Please see the illustrations in:
    Thank you all, and Cheers!

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