排序方式: 共有10条查询结果,搜索用时 15 毫秒
1
1.
M. Tarasov L. Kuz’min E. Stepantsov I. Agulo A. Kalabukhov M. Fominskii Z. Ivanov T. Claeson 《JETP Letters》2004,79(6):298-303
The voltage response of a thin-film normal-metal hot-electron bolometer based on a SINIS (superconductor-insulator-normal metal-insulator-superconductor) structure to the radiation of a high-temperature Josephson junction in the terahertz frequency region was measured. Bolometers were integrated with planar log-periodic and double-dipole antennas, and Josephson junctions were integrated with log-periodic antennas. Measurements showed that the Josephson junction at a temperature of 260 mK was overheated by the transport current, so that its electron temperature exceeded 3 K at a bias voltage of 1 mV. The maximum response of a bolometer with a double-dipole antenna was observed at a frequency of 300 GHz, which agreed well with the calculated value. The Josephson radiation was observed at frequencies up to 1.7 THz. The voltage response of a bolometer reached 4×108 V/W, and the total noise-equivalent power reached 1.5×10?17 W/Hz1/2. 相似文献
2.
Tarasov M. Gunbina A. Lemzyakov S. Nagirnaya D. Fominskii M. Chekushkin A. Koshelets V. Goldobin E. Kalaboukhov A. 《Physics of the Solid State》2021,63(10):1564-1568
Physics of the Solid State - Prototypes of the design of Josephson traveling-wave parametric amplifier based on aluminum superconductor–insulator–superconductor junctions in the form of... 相似文献
3.
V. N. Nevolin V. Yu. Fominskii A. G. Gnedovets V. E. Koshmanov 《Technical Physics》2005,50(6):705-710
Results are presented from experimental studies of pulsed plasma flows generated by nanosecond laser pulses with an intensity
of 7 × 108 W/cm2 from a solid-state target in a strong electric field. The current pulses through the laser target and the depth distributions
of the iron ions implanted in a silicon substrate to which a negative high-voltage pulse was applied are measured. The physical
processes occurring in laser plasma with an initial iron ion density of 6 × 1010 cm−3 are simulated numerically by the particle-in-cell method for different delay times and different shapes of the accelerating
high-voltage pulse. The model developed allows one to calculate the ion flows onto the processed substrate, the electron flows
onto the target, and the energy spectra of the implanted ions. The results from computer simulations are found to be in good
agreement the experimental data. 相似文献
4.
5.
V. N. Nevolin V. Yu. Fominskii A. G. Gnedovets R. I. Romanov 《Technical Physics》2009,54(11):1681-1688
The formation of thin-film coatings of molybdenum diselenide is studied during the deposition of a laser-induced material
flux using a shield that is placed on the path of the expansion of this flux in order to trap the droplet fraction. To increase
the efficiency of atomic scattering into the shadow zone (behind the shield), deposition is carried out in an inert gas (argon).
As the argon pressure increases to 2 Pa, low-density coatings with a developed surface relief form in the shadow zone. When
a negative bias voltage is applied to a substrate, the quality of the coating increases substantially. Numerical experiments
based on the combination of two computer models that describe physical processes on the atomic level using Monte Carlo methods
are performed to reveal the factors that affect the thickness, chemical composition, and structure of the MoSe
x
coatings deposited in the shadow zone. The results of calculating the dynamics of the laser-induced atomic flux in a chamber
with a shield are used to simulate the coating growth. The deposition of a scattered atomic flux under conditions of surface
bombardment by incident particles is shown to substantially increase the coating density and to smooth away the surface relief. 相似文献
6.
M. A. Tarasov L. S. Kuzmin V. S. Edelman N. S. Kaurova M. Yu. Fominskii A. B. Ermakov 《JETP Letters》2010,92(6):416-420
A multielement bolometric receiver system has been developed to measure the power and polarization of radiation at a calculated
frequency of 345 GHz. Arrays of ten series-parallel connected cold-electron bolometers have been pairwise integrated into
orthogonal ports of a cross-slot antenna. Arrays are connected in parallel in the high-frequency input signal and in series
in the output signal, which is measured at a low frequency, and in a dc bias. Such an array makes it possible to increase
the output resistance by two orders of magnitude as compared to an individual bolometer under the same conditions of high-frequency
matching and to optimize the matching with the JFET amplifier impedance up to dozens of megohms. Parallel connection ensures
matching of the input signal to the cross-slot antenna with an impedance of 30 Ω on a massive silicon dielectric lens. At
a temperature of 100 mK, a response to the thermal radiation of a thermal radiation source with an emissivity of 0.3, which
covers the input aperture of the antenna and is heated to 3 K, is 25 μV/K. Taking into account real noise, the optical fluctuation
dc sensitivity is 5 mK, the estimated sensitivity corresponding to the noise of the amplifier is about 10−4 K/Hz1/2, and the noise-equivalent power is about (1–5) × 10−17 W/Hz1/2. 相似文献
7.
The structural state and tribological properties of gradient and composite antifriction coatings produced by pulsed laser
codeposition from MoSe2(Ni) and graphite targets are studied. The coatings are deposited onto steel substrates in vacuum and an inert gas, and an
antidrop shield is used to prevent the deposition of micron-size particles from a laser jet onto the coating. The deposition
of a laser jet from the graphite target and the application of a negative potential to the substrate ensure additional high-energy
atom bombardment of growing coatings. Comparative tribological tests performed at a relative air humidity of ∼50% demonstrate
that the “drop-free” deposition of a laser-induced atomic flux in the shield shadow significantly improves the antifriction
properties of MoSe
x
coatings, decreasing the friction coefficient from 0.07 to 0.04. The best tribological properties, which combine a low friction
coefficient and high wear resistance, are detected in drop-free MoSe
x
coatings additionally alloyed with carbon (up to ∼55 at %) and subjected to effective bombardment by high-energy atoms during
growth. Under these conditions, a dense nanocomposite structure containing the self-lubricating MoSe2 phase and an amorphous carbon phase with a rather high concentration of diamond bonds forms. 相似文献
8.
M. A. Tarasov L. S. Kuz’min M. Yu. Fominskii I. E. Agulo A. S. Kalabukhov 《JETP Letters》2003,78(11):714-717
Normal-metal hot-electron bolometers, each of which contains two superconductor-insulator-normal metal (SIN) junctions for electron cooling and two SIN junctions for temperature measurements, were fabricated and experimentally studied. The electron cooling by SIN junctions is an analog of the Peltier effect and allows one to reduce the effective electron temperature of a bolometer. The electron temperature was determined from the ratio of the differential resistance to normal one for several values of a constant bias. At a phonon temperature of 250 mK, the resistance ratio at zero bias reached 1000, which was close to the theoretical value for an ideal SIN junction. A decrease in the electron temperature from 250 to 90 mK was obtained. 相似文献
9.
Novel hydroxyphosphoranes were synthesized using the oxidative method from triphenylphosphine, 1,1′-dihydroxydicyclohexyl,
benzopinacol, and aminophenol in the presence oftert-butyl hydroperoxide. Hydroxyphosphoranes were also obtained from triphenylphosphine oxide, and the series of dihydric phenols
and diols mentioned above.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1779–1781, October, 1993. 相似文献
10.
Normal-metal hot-electron bolometer with capacitive coupling (CCNHEB) is a further development of the concept of a normal-metal hot-electron bolometer with Andreev mirrors (ANHEB). It was proposed to eliminate the frequency and energy restrictions inherent in ANHEB, in which Andreev mirrors act efficiently only with relatively long absorbers and at energies below the superconducting gap. An important advantage of the CCNHEB is its simple topology, in which the same tunnel junctions provide thermal decoupling, noise protection, temperature measurement, and it can be used for electron cooling. The temperature response of the bolometer was measured at temperatures down to 260 mK. The observed response dV/dT=1.7mV/K corresponds to the sensitivity S=0.4×109V/W. The measured noise at the amplifier output with this sample was found to be V na =4nV/Hz1/2, which corresponds to a noise-equivalent power of 10?17W/Hz1/2. To measure optical response, black-body radiation was used as a source of signal inside the cryostat. The source was a thin NiCr film sputtered on a thin sapphire substrate and suspended by nylon threads. Optical measurements proved to be in good agreement with the dc measurements. 相似文献
1