ILL sets a new record for ultracold neutrons in the world using liquid 4He

ILL sets a new record for ultracold neutrons in the world using liquid 4He: "Neutrons were discovered nearly a century ago, but still hold a few secrets. For example, a lone neutron can transform into other subatomic particles - a proton, an electron and an electron antineutrino - but efforts to measure just how long this decay takes have come up with different numbers.
Such decay times are fundamental in the "Standard Model" of physics, which aims to describe in detail how matter as we now know it came to be in the earliest moments of the Universe's history, and also shed light on the fusion happening for example in stars.
The Standard Model also suggests that despite having no net charge, there is a small separation of charges within neutrons that would give them what is known as an electric dipole moment - a kind of electric north and south pole. However, experiments have until now been too inexact to measure it." ... and so the new approach uses liquid 4He: "It uses superfluid helium-4 at a temperature of -269C - just four degrees above absolute zero - to slow the neutrons down, taming them toward the 55-per-cubic-centimetre benchmark." Read more: http://www.bbc.co.uk/news/science-environment-14991502