Improvement of Plug-in Wire for 200-pixel Superconducting Tunnel Junction X-ray Detector Array on Helium Three Cryostat

The design of plug-in wire system is improved for 200-pixel superconducting tunnel junction (STJ) array of X-ray detector on a helium three cryostat. The electrical connections between the STJ array to the room temperature electronics consists of plural wire modules, which have connectors at the both ends. A flexible coaxial cable with electrical conductors of stainless steel (SUS-FFC) is manufactured and attached to make the electrical connection between room temperature to the 3 K stage. After the installation of SUS-FFC, temperature of the cold stage is 302 mK, and the holding time is more than 115 hours. Compared with the previous setup, the temperature of 3He stage decreased 5 mK, and the holding time increased 30 hours.