Plug-In Cryogenic System for Cartridge-Type SIS Receivers

Sozo Yokogawa, Yutaro Sekimoto, Masahiro Sugimoto, Takeshi Okuda, Tomohiko Sekiguchi, Toshiaki Kamba, Ken'ichi Tatematsu, Tetsuo Nishino, Hideo Ogawa, Kimihiro Kimura, Kazufusa Noda, Katsuhiro Narasaki
2003 Nippon Tenmon Gakkai obun kenkyu hokoku  
We developed a cryogenic system, which houses 3 cartridge-type superconductorinsulator-superconductor receivers for millimeter and submillimeter wavelengths. Since it was designed as a prototype receiver of the Atacama Large Millimeter/ submillimeter Array (ALMA), high stability, accurate alignment, and easy handling were required. To meet these requirements, the cryogenic system included the following technologies: 1) a thermal link without screws for receiver cartridges; 2) a central support
more » ... a central support structure to reduce vacuum and gravitational deformation; 3) bellows structures to reduce mechanical vibration of the cryocooler; and 4) a 3-stage Gifford McMahon (GM) cryocooler with an He pot (temperature stabilizer) to reduce the thermal ripple. The cryostat and receiver cartridges are composed of three stages. The temperatures on the 4 K, 12 K, and 100 K stages of the cartridge are 3.5 K, 13.4 K, and 78.3 K, respectively. The thermal conductances of the thermal links showed high performances of 1.7 W K −1 at the 4 K stage, 5.6 W K −1 at the 12 K stage, and 3.3 W K −1 at the S. Yokogawa et al. Cryogenic System for SIS Receiver [Vol. , 100 K stage. The mechanical vibration on the 4 K stage of the cartridge was reduced to one-tenth, as small as ≈ 2 µm peak-to-peak, compared to that on the 4 K coldhead of the cryocooler, ≈ 20 µm peak-to-peak. The temperature ripple on the cartridge was reduced to as small as 2 mK peak-to-peak, which corresponds to one-seventh of the ripple on the 4 K coldhead with an He pot. ∆T is an expected temperature loss originating in the thermal link.
doi:10.1093/pasj/55.2.519 fatcat:ugcweubiwfgqdmfmql7dgyes5m