Two Nobel Prizes connected to CERN
The 2003 Nobel Prizes in Physics and in Physiology or Medicine, announced last week, both have connections with particle physics and CERN.
Alexei Abrikosov, Vitaly Ginzburg and Anthony Leggett have received the prize in physics for their "pioneering contributions to the theory of superconductors and superfluids". The most important superconducting materials technically have proved to be those known as type II superconductors, which allow superconductivity and magnetism to exist at the same time and remain superconductive in high magnetic fields. The coils for the superconducting magnets in CERN's Large Hadron Collider are made from niobium-titanium alloy - a type II superconductor.
Abrikosov, who is now at the Argonne National Laboratory, was working at the Kapitsa Institute for Physical Problems in his native Moscow when he succeeded in formulating a new theory to explain the behaviour of type II superconductors. This theory was based on work in the 1950s by Ginzburg at the P N Lebedev Physical Institute in Moscow.
The helium used to cool the LHC magnets is the common isotope, helium-4, which is superfluid at 1.9 K, the operating temperature of the LHC. However helium also exists as a rarer isotope, helium-3, which becomes superfluid only at very much lower temperatures around 2 mK. The contribution of Leggett, now at the University of Illinois, Urbana, has been to develop the decisive theory, while at Sussex University in the UK in 1970s, to explain superfluidity in helium-3.
Paul Lauterbur from Urbana, Illinois, and Peter Mansfield of Nottingham in the UK have been rewarded with Nobel prize in medicine or physiology for their discoveries in magnetic resonance imaging. The nuclear resonance phenomenon used in magnetic resonance imaging was first demonstrated, for protons, in 1946 by Felix Bloch and Edward Mills Purcell, who received the Nobel prize in Physics in 1952. Bloch went on to be the first Director General of CERN. Today MRI is used to examine almost all organs of the body, and is especially valuable in imaging the brain and spinal cord.
