| 1. |
- Wild, W., et al.
(författare)
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Millimetron—a large Russian-European submillimeter space observatory
- 2009
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Ingår i: Experimental Astronomy. - : Springer Science and Business Media LLC. - 0922-6435 .- 1572-9508. ; 23:1, s. 221-244
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Tidskriftsartikel (refereegranskat)abstract
- Millimetron is a Russian-led 12 m diameter submillimeter and far-infrared space observatory which is included in the Space Plan of the Russian Federation for launch around 2017. With its large collecting area and state-of-the-art receivers, it will enable unique science and allow at least one order of magnitude improvement with respect to the Herschel Space Observatory. Millimetron will be operated in two basic observing modes: as a single-dish observatory, and as an element of a ground-space very long baseline interferometry (VLBI) system. As single-dish, angular resolutions on the order of 3 to 12 arc sec will be achieved and spectral resolutions of up to a million employing heterodyne techniques. As VLBI antenna, the chosen elliptical orbit will provide extremely large VLBI baselines (beyond 300,000 km) resulting in micro-arc second angular resolution.
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| 2. |
- Smirnov, A. V., et al.
(författare)
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The Current Stage of Development of the Receiving Complex of the Millimetron Space Observatory
- 2012
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Ingår i: Radiophysics and Quantum Electronics (English Translation of Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika). - : Springer Science and Business Media LLC. - 0033-8443 .- 1573-9120. ; 54:8-9, s. 557-568
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Tidskriftsartikel (refereegranskat)abstract
- We present an overview of the state of the onboard receiving complex of the Millimetron space observatory in the development phase of its preliminary design. The basic parameters of the onboard equipment planned to create and required for astrophysical observations are considered. A review of coherent and incoherent detectors, which are central to each receiver of the observatory, is given. Their characteristics and limiting parameters feasible at the present level of technology are reported.
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| 3. |
- Jung, P., et al.
(författare)
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Multistability and switching in a superconducting metamaterial
- 2014
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723 .- 2041-1723. ; 5
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Tidskriftsartikel (refereegranskat)abstract
- The field of metamaterial research revolves around the idea of creating artificial media that interact with light in a way unknown from naturally occurring materials. This is commonly achieved using sub-wavelength lattices of electronic or plasmonic structures, so-called meta-atoms. One of the ultimate goals for these tailored media is the ability to control their properties in situ. Here we show that superconducting quantum interference devices can be used as fast, switchable meta-atoms. We find that their intrinsic nonlinearity leads to simultaneously stable dynamic states, each of which is associated with a different value and sign of the magnetic susceptibility in the microwave domain. Moreover, we demonstrate that it is possible to switch between these states by applying nanosecond-long pulses in addition to the microwave-probe signal. Apart from potential applications for this all-optical metamaterial switch, the results suggest that multistability can also be utilized in other types of nonlinear meta-atoms. © 2014 Macmillan Publishers Limited. All rights reserved.
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| 4. |
- Faley, M. I., et al.
(författare)
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High-T-c SQUID biomagnetometers
- 2017
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Ingår i: Superconductor Science & Technology. - : IOP Publishing. - 0953-2048 .- 1361-6668. ; 30:8
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, we review the preparation technology, integration in measurement systems and tests of high-T-c superconducting quantum interference devices (SQUIDs) intended for biomagnetic applications. A focus is on developments specific to Forschungszentrum Julich GmbH, Chalmers University of Technology, MedTech West, and the University of Gothenburg, while placing these results in the perspective of those achieved elsewhere. Sensor fabrication, including the deposition and structuring of epitaxial oxide heterostructures, materials for substrates, epitaxial bilayer buffers, bicrystal and step-edge Josephson junctions, and multilayer flux transformers are detailed. The properties of the epitaxial multilayer high-T-c direct current SQUID sensors, including their integration in measurement systems with special electronics and liquid nitrogen cryostats, are presented in the context of biomagnetic recording. Applications that include magnetic nanoparticle based molecular diagnostics, magnetocardiography, and magnetoencephalography are presented as showcases of high-T-c biomagnetic systems. We conclude by outlining future challenges.
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| 5. |
- Tarasov, Mikhail, 1954, et al.
(författare)
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Development of Josephson Traveling-Wave Parametric Amplifier Based on Aluminum SIS Junctions
- 2021
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Ingår i: Physics of the Solid State. - 1063-7834 .- 1090-6460. ; 63:10, s. 1564-1568
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Tidskriftsartikel (refereegranskat)abstract
- Prototypes of the design of Josephson traveling-wave parametric amplifier based on aluminum superconductor–insulator–superconductor junctions in the form of direct-current SQUIDs included in central conductor of coplanar line are developed, fabricated, and investigated. Three manufacturing methods for the fabrication of such devices are tested: two of them using shadow evaporation and one using magnetron sputtering and direct electron-beam lithography. Current–voltage characteristics of the junctions are measured at 0.3 K. A cryogenic setup for the measurement of spectral characteristics of such amplifier containing cold semiconductor amplifier with circulator and cooled attenuators of the channels of input signal and pump is developed. The absorption spectrum of coplanar directional coupler with a quarter-wave resonator dedicated for measurements of short chains from one to 27 SQUIDs is measured.
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| 6. |
- Tan, B. K., et al.
(författare)
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Investigation of the performance of an SIS mixer with Nb-AlN-NBN tunnel junctions in the 780-950 GHz frequency band
- 2018
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Ingår i: 2018 29th IEEE International Symposium on Space Terahertz Technology, ISSTT 2018. ; , s. 139-142
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Konferensbidrag (refereegranskat)abstract
- In this paper, we present preliminary measured performance of an SIS mixer employing a Nb/AIN/NbN tunnel junction in the frequency range of 780-950 GHz range. The mixer design is an upgrade of the Carbon Heterodyne Array of the Max-Planck-Institute Plus (CHAMP+) mixer, coupled with an easy to fabricate smooth-walled horn. The noise temperature of the mixer is measured using the standard Y-factor method, but all the RF optics is enclosed in the cryostat. We use a rotating mirror in the cryostat to switch between a room temperature load and a 4 K blackbody load. With this method, we have measured a noise temperature of 330 K around 850 GHz, corrected for a mismatch between a reduced height rectangular waveguide at the input of the mixer block and a full height waveguide at the output of the horn. To remove this mismatch we now plan to redesign a new mixer chip with a full-height waveguide back-piece. The expected performance of the new mixer chip is also reported.
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