The CERN Axion Solar Telescope (CAST) : an update

The CERN Axion Solar Telescope(CAST), a 10 meter long LHC, 9 Tesla, test magnet is mounted on a moving platform that tracks the sun about 1.5 hours during sunrise, again during sunset. It moves ±8 0 vertically and ±40 0 horizontally. It has been taking data continuously since July 10, 2003. Data analyzed thus far yield an upper bound on the photon- axioncoupling constant, g aγγ ⩽ 3 × 10 −10 GeV −1 for axionmasses less than 5 × 10 −2 eV.