[en] The process of hydrogen liquefaction due to the heat exchange with vaporizing helium is analysed. The temperature conditions of heat exchangers are considered taking into account the thermodynamical properties of gases and the gas flows are calculated. To liquefy cooled hydrogen at gas pressure equal to 1 atm, twice as much helium is needed in comparison with the cooling from room temperature to condensation temperature. To increase the liquefaction efficiency half as much again the cooling to 15 deg K of hydrogen compressed to 25 atm is proposed followed by its orificing to atmospheric pressure. The results of calculation are tabulated

[en] The circuit of hydrogen liquefaction by means of a heat exchange with cold helium vapour is considered in which the hydrogen flows freely to a condenser due to the rarity at its liquefaction. The dependence of the temperature and the pressure in the condenser on a helium flow and heat load on the condenser is obtained. The maximum value of helium flow corresponding to the freezing of hydrogen in the condenser is obtained

[en] The construction of liquid deuterium target in which the deuterium liquifaction takes place due to heat exchange with warming helium vapour is presented. The value of liquifaction factor of deuterium is measured. The measured value is in a good agreement with the calculated one, and makes 3.8 l of liquid helium per 1 l of liquid deuterium

[en] Technique for polarized electron beam production by means of charging of the effective cathode area situated in vacuum and magnetic field and forming polarized electron current pulses using pulsed electric field is described. Liquid helium is used as a cathode material to increase both the intensity and degree of the electron beam polarization and to reduce requirements to vacuum depth. Charging of its effective area is accomplished by electron settling in electric field, and limiting surface density of settled electrons is defined realizing conditions of the loss of effective area macroscopic stability. The invention usage allows one to increase polarized electron beam intensity at least by an order and to assure polarization close to 100%, as compared to the date engineering level

[en] An adsorption cryogenic refrigerator of continuous action without units is constructed. An object to be cooled is to placed into the common evaporation zone of two thermosiphons. The refrigerator cooling amounts to ∼ 5 mW at T ∼ 0.6 K and ∼ 30 mW at T ∼ 1 K

[en] The design of a liquid-hydrogen target comprising a hydrogen liquefier and a target head is described. The hydrogen is liquefied by condensation of a helium-vapor cooled surface of a heat exchanger housed inside a condenser. The hydrogen liquefaction efficiency has been measured. The obtained liquefaction coefficient practically coincides with the design value and amounts at the liquefaction rate of up to 0.35 l/hr to 1 l of liquid hydrogen per 2.8 l of liquid helium. The high efficiency of the liquefier and the low evaporation rate of hydrogen from the target, which is about 0.03 to 0.05 m³/hr under normal conditions, have made it possible to extend the time interval between repeated fillings of helium. Now the useful time of the liquid-hydrogen target operation is over two days

[en] The design is given of an economical H₂ and D₂ liquefier which works by the boiling off of liquid He vapour. The decisive role played by the gas condenser in the operation of the liquefier is demonstrated. The relationships between the flow rates of He and of the liquefied gas are calculated and measured. The helium consumption is 2.85 for liquefying 1 l of H₂ and 3.8 1 l of D₂, which agrees with the calculations. (author)

No abstract available

[en] Dilution refrigerator with ³He criogenic circulation is described. With 65 μW incoming heat flow minimum temperature under continuous operation is 124 mK, and under unitary operation - 77 mK. Analysis of refrigerator operation with due account of interrelation of temperatures of condensator and evaporation and dilution chambers is carried out

[en] For the first time a two stage continuous action dilution refrigerator was constructed based on a non-valve adsorption system of ³He pumping, as an upper stage. The minimum temperature of the lower (dilutional) stage was ∼ 0.2 K. The interrelation of the lower and upper refrigerator stages at different ³He circulation rates in the lower was studied. Some essential characteristics of the condensation pump dependence on temperature of still and mixing chamber were calculated and the ways to refrigerator development were determined. The presence of transfer over the superfluid ⁴He film in dilution refrigerators with condensation pumping and its influence on the parameters of refrigerator were discussed