Following the successful leak testing of the cryostat and the helium pipes, it was confirmed that also the main vacuum vessel is leak free.
This week a number of experiments have been made in the cryostat in order to test new vacuum monitoring sensors that have been installed.
Now helium gas is being circulated at room temperature through the magnet cooling pipes and the cryoplant purification system (80 K adsorber). This will flush out any impurities such as air from the system ready for cooling down. In parallel several dry nitrogen purges have been performed in the JT-60SA cryostat to help remove water vapour adsorbed on its multi-layer insulation.