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Träfflista för sökning "AMNE:(TECHNOLOGY Other technology Space engineering) ;pers:(Ferm Sven Erik 1961);pers:(Pavolotsky Alexey 1968)"

Sökning: AMNE:(TECHNOLOGY Other technology Space engineering) > Ferm Sven Erik 1961 > Pavolotsky Alexey 1968

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1.
  • Billade, Bhushan, 1982-, et al. (författare)
  • Performance of the first ALMA Band 5 production cartridge
  • 2011
  • Ingår i: Proceedings of the 22nd International Symposium on Space Terahertz Technology, April 26-28th, 2011 - Tucson, Arizona, USA. ; s. -2
  • Konferensbidrag (refereegranskat)abstract
    • We present performance of the first ALMA Band 5 production cartridge, covering RF frequencies from 163 GHz to 211 GHz. ALMA Band 5 is a dual polarization, sideband separation (2SB) receiver based on all Niobium (Nb) SuperconductorInsulator-Superconductor (SIS) tunnel junction mixer, providing 16 GHz of instantaneous RF bandwidth for the astronomy observations. The 2SB mixer for each polarization employs a quadrature layout. The sideband separation occurs at the output of the IF hybrid that has integrated bias-T for biasing the mixers, and is produced using superconducting thin film technology. Experimental verification of the Band 5 cold cartridge performed together with warm cartridge assembly, confirms the system noise temperature below 45 K, less than five quantum noise (5 hf/k) over most of the RF band, which is to our knowledge, the best results at these frequencies. The measurement of the sideband rejection indicates that the sideband rejection better than 10 dB over 90% of the observational band.
2.
  • Belitsky, Victor, 1955-, et al. (författare)
  • Terahertz Instrumentation For Radio Astronomy
  • 2009
  • Ingår i: International Symposium on Terahertz Science and Technology between Japan and Sweden. ; s. 28-29
  • Konferensbidrag (övrigt vetenskapligt)abstract
    • Radio Astronomy was always a frontrunner in the demand on terahertz technology. Millimetre and sub-millimetre wave receivers operate at ground-based observatories for more than 20 years with real Terahertz instruments making its way to ground-based [1] and space-based observatories, e.g., Herschel HIFI, during last years. In this talk, we will look at the key requirements to the radio astronomy and environmental science terahertz receivers using heterodyne technology. The most promising and established technologies for high-resolution spectroscopy instrumentation will be discussed. Using results of the Group for Advanced Receiver Development for Onsala Space Observatory 20 m telescope, for Atacama Pathfinder Experiment (APEX) telescope and ALMA Project Band 5, we will illustrate the trends and achievements in the terahertz instrumentation for radio astronomy.
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3.
  • Belitsky, Victor, 1955-, et al. (författare)
  • Prototype ALMA Band 5 Cartridge:Design and Performance
  • 2009
  • Ingår i: Proceedings of the 20TH INTERNATIONAL SYMPOSIUM ON SPACE TERAHERTZ TECHNOLOGY, Charlottesville, VA, USA, April 20-22, 2009, s. 2-5.
  • Konferensbidrag (refereegranskat)abstract
    • The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of East Asia, Europe and North America in cooperation with the Republic of Chile and aims to build an interferometer radio telescope consisting of more than 60 antennas. The instrument is under construction at the Llano de Chajnantor, about 50 km east of San Pedro de Atacama, Chile. This work presents a part of ALMA frontend, the development, design and performance of one of the frequency channels of the ALMA receiver, the Band 5 prototype cartridge for 163 – 211 GHz frequency band.
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4.
  • Strandberg, Magnus, 1975-, et al. (författare)
  • Analysis, Simulation and Design of Cryogenic Systems for ALMA Band 5 Prototype Cartridge
  • 2009
  • Ingår i: Proceedings of the 20TH INTERNATIONAL SYMPOSIUM ON SPACE TERAHERTZ TECHNOLOGY, Charlottesville, VA, USA, April 20-22, 2009. ; s. 307-310
  • Konferensbidrag (refereegranskat)abstract
    • The ALMA frontend is designed for ten separate receivers channels covering 30-960 GHz range; the receiver accommodates these receiver channels as pluggable, fully electrically autonomous cartridges. These cartridges share the same cryogenic cooler. ALMA Band 5 cartridge is a dual-polarization heterodyne receiver employing 2SB SIS mixers with IF band 4-8 GHz and covers the frequency 163-211 GHz. The prototype for the ALMA Band 5 cartridge development is carried out by Group for Advanced Receiver Development (GARD) in Gothenburg, Sweden with the aim to provide six Band 5 cartridges for ALMA Project. The first prototype cartridge is currently being assembled. ALMA Band 5 cartridge is the lowest frequency channel in the ALMA receiver that employs all cold optics and thus has the biggest rim of the mirrors amongst other ALMA bands placed on the 4K cartridge plate. The size of the optics and its supporting brackets puts severe constrains on the design of the receiver. Another important issue of the Band 5 cartridge design, as well as other ALMA cartridges, is a very tight thermal budget. In this report, we present analysis and simulation results for the thermal and mechanical design of the ALMA Band 5 cartridge that has been carried out using different FEM software packages such as CFDesign and ANSYS. We compare simulation results obtained with these software and the analytical calculations. For the mechanical design, the major focus was put on the cartridge and the optics support structure deformation with cooling.
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