[en] A fast superconducting bolometer based on double Ag+Sn films is discribed. The films have the transition temperature of about 2.1 K. A He-filled metal cryostat was used to cool the bolometer. The volume of the He cylinder is 1.5 l. A solenoid was used to stabilize automatically the working point of the bolometer and to correct the temperature of the film superconducting transition. The bolometer frequency responce for HeI and HeII is investigated, and it is shown that the HeII cooled bolometer has a uniform frequency responce within the range of 1.6 Hz to 30 MHz and its detecting power is 10⁸ cmxHzsup(1/2)xWsup(-1) at the time constant of 5 ns. The HeII-cooled bolometer showed smooth decreasing of the sensitivity with frequency increase. In addition, the HeI-cooled bolometer has a higher level of low frequency temperature noises and a lesser detecting power as compared to the HeII-cooled bolometer

[en] Short communication. 4 refs

[en] Helium temperature fluctuations have been studied. The measurements have been carried out with the aid of ultraconducting temperature transducers on the basis of binary Pb-Sn layers with the transition temperature 1.8-4.5 K. The equipment has made it possible to measure the fluctuation spectral composition in the 1-400 Hz frequency range with 1.5x10sup(-8) KxHzsup(-1/2) sensitivity. Helium temperature fluctuation spectra have been measured in the following phase states: in liquid HeI and HeII and gaseous He. The spectra appear as Δ Tsup(-2) approximately 1/fsup(3). The main fluctuation source - the helium bubble boiling in a vessel, as well as on the transducer at scattering power P > 10^-4 Vtxcm^-2. Temperature fluctuations in liquid HeII are 200 times less than in HeI. In the frequency range 1.6-800 Hz it has been observed the decrease of sensitivity with frequency increase for transducers in liquid HeI and gaseous He. In HeII there has been no dependence of sensitivity on frequency. Taking account of the measured coefficient of transducer transfer the transformation of temperature fluctuations into power fluctuations has been performed

[en] NdGaO₃ substrates with 0.5 mm thickness, on which YBa₂Cu₃O_7-x film with ∼ 0.1 μm thickness is formed by pulse laser spray-coating and above it - ∼ 0.3 μm thickness gold film formed by magnetron spray-coating, are used. Then a bow-type antenna and microbolometer are sequentially produced using photolithograpy. Temperature dependences of R, noise stress S_v^1/2 and V/W-sensitivity r; noise spectra in 10-10⁶ Hz frequency range, thermal less coefficient G and microbolometer time constant τ are measured. 9 refs., 3 figs

[en] GdBaCuO superconducting bolometer on the basis of the temperature dependence of magnetic screening of a HTSC film is described. It is shown the principal possibility of development of very sensitive HTSC bolometers based on the magnetic susceptibility

[en] Results of noise investigations of Y-Ba-Cu-O film samples, prepared by laser evaporation are presented. Films of YBa₂Cu₃O_7-x composition of 100-1500 A thickness were sprayed on SrTiO₃ substrates with 1 mm thickness. Frequency dependences of noise in 1.6 Hz - 20 kHz range, current dependences of noise, as well as dependences of noise on temperature and resistance were measured. It is shown that noise growth is observed with increase of resistance in the region of transition from superconducting to normal state at R=(0.2-1) R_N and then, up to resistance, corresponding to room temperature. This phenomenon can be related with increase of the share of normal zones, their structural defects or contacts between grains

[en] Noise properties of YBa₂Cu₃O_7-x films on SrTiO₃ substrates were studied. Epitaxial films produced by laser ablation feature a perfect structure, a narrow superconducting transition, a strong pinning and a very low flicker noise. It is ascertained that in the normal state the value of 1/f noise increases with the growth of dislocation density. The lowest noise characterized by the Hooge noise parameter (2-3) x 10^-6 is observed for dislocation density of (8-12) μm^-2

[en] Short communication. 2 refs

[en] Short communication. 2 refs.; 1 tab

[en] Short communication. 4 refs