A liquefier system for keV neutron radiative capture reactions of a gaseous sample

A system for liquefying a gaseous sample has been constructed in order to study the neutron-capture reaction of a sample using keV neutrons. It consists of a cryostat with a refrigeration system, a temperature-control system, a gas-handling system, and a vacuum system. It can liquefy all gaseous samples (except for He). Since we use a small amount of a compound of light elements, such as polycarbonate and acrylic resin, as the vacuum cell and the sample cell, we can measure the small neutron capture cross section of a sample having a few μb with a high S/N value by employing a prompt γ-ray detection method. The system has been shown to operate continuously for a long-term experiment using natural Ne gas without any problem.