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- Eriksson, Anders, et al.
(författare)
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RPC-LAP : The Rosetta Langmuir probe instrument
- 2007
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Ingår i: Space Science Reviews. - : Springer Science and Business Media LLC. - 0038-6308 .- 1572-9672. ; 128:04-jan, s. 729-744
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Forskningsöversikt (refereegranskat)abstract
- The Rosetta dual Langmuir probe instrument, LAP, utilizes the multiple powers of a pair of spherical Langmuir probes for measurements of basic plasma parameters with the aim of providing detailed knowledge of the outgassing, ionization, and subsequent plasma processes around the Rosetta target comet. The fundamental plasma properties to be studied are the plasma density, the electron temperature, and the plasma flow velocity. However, study of electric fields up to 8 kHz, plasma density fluctuations, spacecraft potential, integrated UV flux, and dust impacts is also possible. LAP is fully integrated in the Rosetta Plasma Consortium (RPC), the instruments of which together provide a comprehensive characterization of the cometary plasma.
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- Karlsson, Tomas, 1964-, et al.
(författare)
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The MEFISTO and WPT Electric Field Sensors of the Plasma Wave Investigation on the BepiColombo Mio Spacecraft Measurements of Low and High Frequency Electric Fields at Mercury
- 2020
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Ingår i: Space Science Reviews. - : Springer Nature. - 0038-6308 .- 1572-9672. ; 216:8
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Forskningsöversikt (refereegranskat)abstract
- This paper describes the design of MEFISTO (Mercury Electric Field In-Situ Tool) and WPT (Wire Probe Antenna) electric field sensors for Plasma Wave Investigation (PWI) on the BepiColombo Mio spacecraft (Mercury Magnetospheric Orbiter, MMO). The two sensors will enable the first observations of electric fields, plasma waves and radio waves in and around the Hermean magnetosphere and exosphere. MEFISTO and WPT are dipole antennas with 31.6 m tip-to-tip length. Each antenna element has a spherical probe at each end of the wire (15 m length). They are extended orthogonally in the spin plane of the spacecraft and enable measurements of the electric field in the frequency range of DC to 10 MHz by the connection to two sets of receivers, EWO for a lower frequency range and SORBET for higher frequencies. In the initial operations after the launch (20 Oct. 2018), we succeeded to confirm the health of both antennas and to release the launch lock of the WPT. After Mercury orbit insertion planned at the end of 2025, both sensors will be fully deployed and activate full operations of the PWI electric field measurements.
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- Knudsen, D. J., et al.
(författare)
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Thermal ion imagers and Langmuir probes in the Swarm electric field instruments
- 2017
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Ingår i: Journal of Geophysical Research - Space Physics. - : AMER GEOPHYSICAL UNION. - 2169-9380 .- 2169-9402. ; 122:2, s. 2655-2673
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Tidskriftsartikel (refereegranskat)abstract
- The European Space Agency's three Swarm satellites were launched on 22 November 2013 into nearly polar, circular orbits, eventually reaching altitudes of 460 km (Swarm A and C) and 510 km (Swarm B). Swarm's multiyear mission is to make precision, multipoint measurements of low-frequency magnetic and electric fields in Earth's ionosphere for the purpose of characterizing magnetic fields generated both inside and external to the Earth, along with the electric fields and other plasma parameters associated with electric current systems in the ionosphere and magnetosphere. Electric fields perpendicular to the magnetic field.B are determined through ion drift velocity v(i) and magnetic field measurements via the relation.E. = -.vi x.B. Ion drift is derived from two-dimensional images of low-energy ion distribution functions provided by two Thermal Ion Imager (TII) sensors viewing in the horizontal and vertical planes;v(i) is corrected for spacecraft potential as determined by two Langmuir probes (LPs) which also measure plasma density ne and electron temperature T-e. The TII sensors use a microchannel-plate-intensified phosphor screen imaged by a charge-coupled device to generate high-resolution distribution images (66 x 40 pixels) at a rate of 16 s(-1). Images are partially processed on board and further on the ground to generate calibrated data products at a rate of 2 s(-1); these include.vi,.E., and ion temperature T-i in addition to electron temperature Te and plasma density n(e) from the LPs.
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- Lindqvist, Per-Arne, 1954-, et al.
(författare)
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The Spin-Plane Double Probe Electric Field Instrument for MMS
- 2016
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Ingår i: Space Science Reviews. - : Springer Science+Business Media B.V.. - 0038-6308 .- 1572-9672. ; 199:1-4, s. 137-165
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Forskningsöversikt (refereegranskat)abstract
- The Spin-plane double probe instrument (SDP) is part of the FIELDS instrument suite of the Magnetospheric Multiscale mission (MMS). Together with the Axial double probe instrument (ADP) and the Electron Drift Instrument (EDI), SDP will measure the 3-D electric field with an accuracy of 0.5 mV/m over the frequency range from DC to 100 kHz. SDP consists of 4 biased spherical probes extended on 60 m long wire booms 90(a similar to) apart in the spin plane, giving a 120 m baseline for each of the two spin-plane electric field components. The mechanical and electrical design of SDP is described, together with results from ground tests and calibration of the instrument.
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- Maksimovic, M., et al.
(författare)
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The Solar Orbiter Radio and Plasma Waves (RPW) instrument
- 2020
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Ingår i: Astronomy and Astrophysics. - : EDP SCIENCES S A. - 0004-6361 .- 1432-0746. ; 642
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Tidskriftsartikel (refereegranskat)abstract
- The Radio and Plasma Waves (RPW) instrument on the ESA Solar Orbiter mission is described in this paper. This instrument is designed to measure in-situ magnetic and electric fields and waves from the continuous to a few hundreds of kHz. RPW will also observe solar radio emissions up to 16 MHz. The RPW instrument is of primary importance to the Solar Orbiter mission and science requirements since it is essential to answer three of the four mission overarching science objectives. In addition RPW will exchange on-board data with the other in-situ instruments in order to process algorithms for interplanetary shocks and type III langmuir waves detections.
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- Ronchi, Emanuele, et al.
(författare)
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A bipolar LED drive technique for high performance, stability and power in the nanosecond time scale
- 2009
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Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576. ; 599:2-3, s. 243-247
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Tidskriftsartikel (refereegranskat)abstract
- Pulsed light sources are often used to monitor the stability of light detectors such as photomultiplier tubes. Light emitting diodes (LEDs) are suitable for this due to their high specific light yield. While pulsed operation in the region of [mu]s is generally accessible with most LEDs and drivers, the ns time scale often represents a technical challenge. This paper describes a technique of bipolar LED drive that can produce light pulses of a few ns at high stability, reliability and power. The driver also offers control over the properties of the light pulse produced such as shape, intensity and repetition rate. This approach has been studied in 2003 and implemented in 2004 for two fusion neutron spectrometers at the Joint European Torus (JET) namely the Magnetic Proton Recoil upgrade (MPRu) and the Time Of Flight Optimized for Rate (TOFOR). A driver has been manufactured and connected to the scintillation detectors of each spectrometer through an optical fiber distribution network. Both MPRu and TOFOR have been successfully relying on this system for calibration and performance monitoring for several years, confirming the long-term stability and reliability of this technique.
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