The article presents a brief review of cooling systems that ensure various temperature levels (from 0.1 K to 230 K) for radio astronomical receivers of photonic and electronic (or optical and radio) devices. The features of various cooling levels and the requirements for the design of the cooling systems are considered in detail, as well as the approaches to designing interfaces for cooled receivers: vacuum, cryogenic, electrical, mechanical, optical, and other interfaces required for effective operation. The presented approaches to design are illustrated by a series of joint developments of the authors carried out over the past 45 years, including those produced over the past year.

A helium-3 adsorption refrigerator cooled with a pulse-tube cryocooler is developed. The refrigerator has two stages of adsorption pumping. The first stage is designed for the condensing and pumping of helium-4, whose cooling capacity is used for the condensation of helium-3. The second stage is designed for pumping helium-3. The final temperature reached by the refrigerator is 0.305 K. This temperature is retained for at least 24 h. The time required for helium recondensation and the obtainment of low temperature is 1.5 h. The cryostat is a self-contained instrument, as it contains no external gas-supply pipelines and the working gas is stored directly within the working volume of the refrigerator. The work is performed in the Frank Laboratory of Neutron Physics of the Joint Institute for Nuclear Research.

Based on the development of top-loading cryostats a horizontal-loading cryostat for cryomagnetic research at the diffractometer DN-12 of IBR-2 has been developed. In this regard, it is...

This article presents the main results and new plans for the development of receivers which are cooled cryogenically to deep cryogenic temperatures and used in optical and radio astronomy research at the Special Astrophysical Observatory of the Russian Academy of Sciences (SAO RAS) on both the Big Telescope Alt-Azimuthal optical telescope (BTA) and the Radio Astronomical Telescope Academy of Sciences (RATAN-600) radio telescope, 600 m in diameter. These two instruments almost completely cover the frequency range from long radio waves to the IR and optical bands (0.25–8 mm on RATAN and 10–0.3 μm, on BTA) with a certain gap in the terahertz part (8–0.01 mm) of the spectrum. Today, this range is of the greatest interest for astronomers. In particular, the ALMA (Atacama Large Millimeter Array) observatory and the worldwide network of modern telescopes called the EVH (Event Horizon Telescope) operate in this range. New developments at SAO RAS are aimed at mastering this part of the spectrum. Cryogenic systems of receivers in these ranges are a key element of the system and differ markedly from the cooling systems of optical and radio receivers that ensure cooling of the receivers to sub-Kelvin temperatures.

A vertically loaded cryostat with a shaft diameter of 80 mm based on a GM SRDK415D cryocooler for operation in the temperature range of 4–300 K is described. This cryostat can operate both in vertical and horizontal positions, almost without losing the final temperature. The time-temperature curves of the sample chamber in the temperature range of 4–150 K in the vertical and horizontal positions of the cryostat are presented. The temperature is adjusted using the controller. Before the experiment, the 25-mbar pressure of heat exchange helium gas is set in the shaft. The cryostat is designed for operation at the NERA spectrometer of the IBR-2 reactor at the Laboratory of Neutron Physics of the Joint Institute for Nuclear Research.

At the Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, work is underway to create gas-filled neutron detectors. To prepare the working mixture of gases, it is necessary to use pure ³He, which is obtained by freezing impurities. A ³He refrigerator is created for this purpose. The refrigerator can also be used to obtain low temperatures in a physics experiment. In this work, the operating modes of the refrigerator are studied. In the continuous mode of ³He circulation, a temperature of 0.78 K is obtained. When ³He vapor is pumped out by an external pump in a single cooling mode, a temperature of 0.52 K is reached. We also study the relaxation modes in which, with pre-condensed ³He, the volume of the container plays the role of a pump. A mode is presented in which the temperature of the evaporator relaxes from 1 to 1.5 K within 11 days.