Tokyo axion helioscope experiment
  A search for solar axions has been performed using an axion helioscope which
is equipped with a 2.3m x 4T superconducting magnet, a gas container to hold
dispersion-matching gas, PIN-photodiode X-ray detectors, and a telescope mount
mechanism to track the sun. In the past measurements, axion mass up to 0.27eV
have been scanned. It has been upgraded to handle dispersion-matching gas
(He-4) of higher density to explore higher mass region. From December 2007
through April 2008, the axion mass region 0.84 < m < 1.00eV was newly explored,
where the axions in the "photon-coupling vs. mass" parameter region of the
preferred axion models were newly searched. From the absence of any evidence, a
limit on axion-photon coupling constant was set to be g < 5.6-13.4e-10/GeV at
95% confidence level in the above mass region.
