Matrices of SINIS Detectors for Terahertz Radioastronomy

Superconductor–insulator–normal metal–insulator–superconductor (SINIS) detectors are developed with promising applications in two scheduled instruments of the space project of the Millimetron radio telescope, as well as ground-based high-altitude BTA (Big Telescope Alt-Azimuthal) and Suffa telescopes. For the multipixel imaging array, two matrix versions are developed: half-wave and electrically small antennas with series and parallel connection of elements in each pixel. In the former case, readout is performed using field-effect transistors; in the latter case, readout is performed using superconducting quantum interferometers (SQUIDs). For multipixel applications, a structure with frequency multiplexing of channels, in which each pixel represents a coplanar resonator connected to a common coplanar line and read using a cryogenic microwave amplifier is developed and fabricated for the first time. As such an amplifier, a prototype of the Josephson traveling-wave parametric amplifier (JTWPA) based on aluminum SIS junctions is developed and fabricated for the first time. Such a design provides fast readout of hundreds of channels over one coaxial line, noise removal with spectrum 1/ f in the readout channel due to an increase in the readout frequency to several gigahertz, as well as reduction of the heat load on a sorption refrigerator due to a decrease in the number of lead wires from several hundred to one coaxial cable.