The JRR-3M reactor at JAERI, one of the most powerful neutron
sources in the world, is used for study of condensed matter physics,
chemistry, biology, materials engineering, and medical sciences.
The machine time for proposed studies from users exceeds the available
machine time by a factor of three. This early construction of
a new beam port is desired.
A neutron bender can deflect a 'white'-spectrum beam from a main
beam line and thereby supply a wide range of wavelengths to a
new scientific instrument. Because neutrons do not have an electric
charge, a new technique using neutron optical phenomena such as
Bragg reflection, has been developed to bend, transport, and focus
a neutron beam. JAERI has developed a new neutron bender using
supermirrors. Neutrons transit the curved mirrors of the bender
with multiple reflections. The Ni/Ti supermirror has 152 layers
evaporated on both sides of 0.3 mm silicon-wafer slits. The Supermirror
can extend the critical angle of external total reflection 2 ~ 3 times beyond that of natural nickel. A new bender with a characteristic
wavelength of 5.0 angstrom has been developed. It has a very small
radius of curvature, 1.6 m. |
