Effective Electron Microrefrigeration by SIN Tunnel Junctions with Advanced Geometry of Electrodes and Normal Metal Traps

We demonstrate effective electron cooling of the normal metal strip by superconductor-insulator-normal metal (SIN) tunnel junctions. The improvement was achieved by two methods: first by using an advanced geometry of the superconducting electrodes for more effective removal of the quasiparticles; and second, by adding a normal metal trap just near the cooling junctions. With simple cross geometry and without normal metal traps, the decrease in electron temperature is 56 mK. With the advanced geometry of the superconducting electrodes, the decrease in electron temperature is 129 mK. With the addition of the normal metal traps, the decrease in electron temperature is 197 mK

Effective Electron Microrefrigeration by SIN Tunnel Junctions with Advanced Geometry of Electrodes and Normal Metal Traps

We demonstrate effective electron cooling of the normal metal strip by superconductor-insulator-normal metal (SIN) tunnel junctions. The improvement was achieved by two methods: first by using an advanced geometry of the superconducting electrodes for more effective removal of the quasiparticles; and second, by adding a normal metal trap just near the cooling junctions. With simple cross geometry and without normal metal traps, the decrease in electron temperature is 56 mK. With the advanced geometry of the superconducting electrodes, the decrease in electron temperature is 129 mK. With the addition of the normal metal traps, the decrease in electron temperature is 197 mK

Superconducting Terahertz Receivers for Space and Ground-based Radio Astronomy

The main task of the RFBR_BRICS project 'Superconducting terahertz receivers for space and ground radio astronomy' is the development of terahertz technologies and the creation of superconductor-insulator-superconductor (SIS) receivers with quantum sensitivity for novel radio telescopes, including ultra-long baseline radio interferometers. This research program brings together scientific groups from four BRICS countries (Brazil, Russia, China and South Africa), which have a high international reputation and successful experience in the development of ultrasensitive receivers. The report discusses the working plan and the first results of the project; in particular development of the SIS-receivers for Russian space program 'Millimetron

Performance of SIS mixers for upgrade of CHAMP+ 7-pixel arrays

We present here the performance of SIS mixers for upgrade of CHAMP+ array instrument on APEX telescope. In total it includes 14 mixers: 7 for the low band (600-720 GHz) and 7 for the high band (790-950 GHz). The mixers are a replacement for the existing set, which was commissioned on APEX in 2006. The low band mixers are based on Nb/AlN/Nb single tunneling SIS junction and high band ones -on Nb/AlN/NbN SIS twin junctions. The corrected DSB noise temperature of the low band mixers is roughly between 60 K and 120 K for the entire frequency range, and the corrected DSB noise temperature of the high band mixers varies from about 200 K at low frequencies to 400 K at the high end

Performance of SIS mixers for upgrade of CHAMP+ 7-pixel arrays

We present here the performance of SIS mixers for upgrade of CHAMP+ array instrument on APEX telescope. In total it includes 14 mixers: 7 for the low band (600-720 GHz) and 7 for the high band (790-950 GHz). The mixers are a replacement for the existing set, which was commissioned on APEX in 2006. The low band mixers are based on Nb/AlN/Nb single tunneling SIS junction and high band ones -on Nb/AlN/NbN SIS twin junctions. The corrected DSB noise temperature of the low band mixers is roughly between 60 K and 120 K for the entire frequency range, and the corrected DSB noise temperature of the high band mixers varies from about 200 K at low frequencies to 400 K at the high end