  We developed a system that continuously maintains a cryocooler for long
periods on a rotating table. A cryostat that holds the cryocooler is set on the
table. A compressor is located on the ground and supplies high-purity (>
99.999%) and high-pressure (1.7 MPa) helium gas and electricity to the
cryocooler. The operation of the cryocooler and other instruments requires the
development of interface components between the ground and rotating table. A
combination of access holes at the center of the table and two rotary joints
allows simultaneous circulation of electricity and helium gas. The developed
system provides two innovative functions under the rotating condition; cooling
from room temperature and the maintenance of a cold condition for long periods.
We have confirmed these abilities as well as temperature stability under a
condition of continuous rotation at 20 revolutions per minute. The developed
system can be applied in various fields; e.g., in tests of Lorentz invariance,
searches for axion, radio astronomy and cosmology, and application of radar
systems. In particular, there is a plan to use this system for a radio
telescope observing cosmic microwave background radiation.
