References of "Jamar, Claude"
     in
Bookmark and Share    
Full Text
See detailAladdin nulling instrument
Barillot, Marc; Coudé Du Foresto, Vincent; Surdej, Jean ULg et al

in Spinoglio, L.; Epchtein, N. (Eds.) 3rd ARENA Conference: An Astronomical Observatory at CONCORDIA (Dome C, Antarctica) (2010)

The ALADDIN project aims at detecting warm dust populations around nearby main sequence stars. In order to achieve the significantly improved sensitivity with respect to existing instruments, the ... [more ▼]

The ALADDIN project aims at detecting warm dust populations around nearby main sequence stars. In order to achieve the significantly improved sensitivity with respect to existing instruments, the architecture of the system is focused and optimised for the mission: ALADDIN implements the nulling interferometry technique at the focal plane of a 2-telescope interferometer mounted on a rotating structural beam. Concerning the beam combining nulling instrument, the ALADDIN design is inherited from a Definition Study of the VLTI/GENIE instrument. In this paper, we demonstrate how the ALADDIN instrument preliminary definition can be made simpler and more representative of a space instrument than GENIE thanks to both the outstanding atmospheric properties of Dome C and the dedicated architecture of the system. Finally, we discuss the compatibility of the instrument with the Antarctic environment and constraints, and underline the experimental and industrial know-how learnt from the MAII and PERSEE nulling breadboards in which our Team is also involved. [less ▲]

Detailed reference viewed: 329 (6 ULg)
Full Text
Peer Reviewed
See detailArray of microsystem for live monitoring of high voltage power lines
Renson, Luc ULg; Jamar, Claude ULg; Guérard, Suzanne ULg et al

in Proceedings of the 1st IOMAC (2005, April)

How to use microsystems placed on power lines environment.

Detailed reference viewed: 123 (14 ULg)
Full Text
Peer Reviewed
See detailVolume phase holographic gratings: large size and high diffraction efficiency
Blanche, Pierre-Alexandre ULg; Gailly, Patrick ULg; Habraken, Serge ULg et al

in Optical Engineering (2004), 43(11), 2603-2612

Volume phase holographic gratings (VPHGs) possess unique properties that make them attractive for numerous applications. After reviewing major VPHG characteristics through theory, we discuss some aspects ... [more ▼]

Volume phase holographic gratings (VPHGs) possess unique properties that make them attractive for numerous applications. After reviewing major VPHG characteristics through theory, we discuss some aspects of the dichromated gelatin recording material and the holographic recording process. The large-scale VPHG research facility set up at the Center Spatial de Liege enables production of VPHGs up to 380 mm in diameter, with fringe frequencies from 315 to 3300 Ip/mm. We describe the work that has been undertaken in our laboratory to remove the last limitations inherent in VPHGs. (C) 2004 Society of Photo-Optical Instrumentation Engineers. [less ▲]

Detailed reference viewed: 45 (9 ULg)
Full Text
See detailMAGRITTE: an instrument suite for the solar atmospheric imaging assembly (AIA) aboard the Solar Dynamics Observatory
Rochus, Pierre ULg; Defise, Jean-Marc ULg; Halain, Jean-Philippe ULg et al

in Society of Photo-Optical Instrumentation Engineers (SPIE) Conference Series (2004, February 01)

The Solar Atmospheric Imaging Assembly (AIA) aboard the Solar Dynamics Observatory will characterize the dynamical evolution of the solar plasma from the chromosphere to the corona, and will follow the ... [more ▼]

The Solar Atmospheric Imaging Assembly (AIA) aboard the Solar Dynamics Observatory will characterize the dynamical evolution of the solar plasma from the chromosphere to the corona, and will follow the connection of plasma dynamics with magnetic activity throughout the solar atmosphere. The AIA consists of 7 high-resolution imaging telescopes in the following spectral bandpasses: 1215Å. Ly-a, 304 Å He II, 629 Å OV, 465 Å Ne VII, 195 Å Fe XII (includes Fe XXIV), 284 Å Fe XV, and 335 Å Fe XVI. The telescopes are grouped by instrumental approach: the MAGRITTE Filtergraphs (R. MAGRITTE, famous 20th Century Belgian Surrealistic Artist), five multilayer EUV channels with bandpasses ranging from 195 to 1216 Å, and the SPECTRE Spectroheliograph with one soft-EUV channel at OV 629 Å. They will be simultaneously operated with a 10-second imaging cadence. These two instruments, the electronic boxes and two redundant Guide Telescopes (GT) constitute the AIA suite. They will be mounted and coaligned on a dedicated common optical bench. The GTs will provide pointing jitter information to the whole SHARPP assembly. This paper presents the selected technologies, the different challenges, the trade-offs to be made in phase A, and the model philosophy. From a scientific viewpoint, the unique combination high temporal and spatial resolutions with the simultaneous multi-channel capability will allow MAGRITTE / SPECTRE to explore new domains in the dynamics of the solar atmosphere, in particular the fast small-scale phenomena. We show how the spectral channels of the different instruments were derived to fulfill the AIA scientific objectives, and we outline how this imager array will address key science issues, like the transition region and coronal waves or flare precursors, in coordination with other SDO experiments. We finally describe the real-time solar monitoring products that will be made available for space-weather forecasting applications. [less ▲]

Detailed reference viewed: 94 (7 ULg)
Full Text
Peer Reviewed
See detailRoughness evolution of some X-UV reflective materials induced by low energy (< 1 keV) ion beam milling
Gailly, Patrick ULg; Jamar, Claude ULg; Fleury-Frenette, Karl ULg et al

in Nuclear Instruments & Methods in Physics Research. Section B, Beam Interactions with Materials and Atoms (2004), 216

Ion beam figuring (IBF) is an advanced technique that is been used for more than 10 years as a final step in the manufacturing of optical elements. It makes use of ion sputtering to correct shape defects ... [more ▼]

Ion beam figuring (IBF) is an advanced technique that is been used for more than 10 years as a final step in the manufacturing of optical elements. It makes use of ion sputtering to correct shape defects but this process may eventually lead to the degradation of the surface roughness. In this study, the evolution of roughness for some optical materials subjected to the ion beam figuring process has been investigated by using optical profilometry and scanning electron microscopy. Emphasis has been made on electroplated nickel, PVD gold and CVD silicon carbide. These materials are often used for X-ray and UV applications but only limited data on their behavior under ion milling is currently available. Roughness measurements have been performed at different etching depths down to 5 mum which is representative of typical IBF treatments. The effects of using different inert gases (Ar, Kr and Xe) with ion energies ranging from 200 to 900 eV have been studied. The observed trends are an important increase of the roughness for electroplated nickel, a slight decrease for PVD gold and a slight increase for CVD silicon carbide. Results are discussed in relation to previous related works and within sputtering considerations. (C) 2003 Elsevier B.V. All rights reserved. [less ▲]

Detailed reference viewed: 26 (3 ULg)
Full Text
Peer Reviewed
See detailOMC: An Optical Monitoring Camera for INTEGRAL - Instrument description and performance
Mas-Hesse, J. M.; Gimenez, A.; Culhane, J. L. et al

in Astronomy and Astrophysics (2003), 411(1), 261-268

The Optical Monitoring Camera (OMC) will observe the optical emission from the prime targets of the gammaray instruments onboard the ESA mission INTEGRAL, with the support of the JEM-X monitor in the X ... [more ▼]

The Optical Monitoring Camera (OMC) will observe the optical emission from the prime targets of the gammaray instruments onboard the ESA mission INTEGRAL, with the support of the JEM-X monitor in the X-ray domain. This capability will provide invaluable diagnostic information on the nature and the physics of the sources over a broad wavelength range. Its main scientific objectives are: ( 1) to monitor the optical emission from the sources observed by the gamma- and X-ray instruments, measuring the time and intensity structure of the optical emission for comparison with variability at high energies, and ( 2) to provide the brightness and position of the optical counterpart of any gamma- or X-ray transient taking place within its field of view. The OMC is based on a refractive optics with an aperture of 50 mm focused onto a large format CCD (1024 x 2048 pixels) working in frame transfer mode (1024 x 1024 pixels imaging area). With a field of view of 5degrees x 5degrees it will be able to monitor sources down to magnitude V = 18. Typical observations will perform a sequence of different integration times, allowing for photometric uncertainties below 0.1 mag for objects with V less than or equal to 16. [less ▲]

Detailed reference viewed: 81 (8 ULg)
See detailThe Herschel-PACS Grating Drive and its controller
Renotte, Etienne ULg; Callut, Eric ULg; Guiot, Marc ULg et al

(2003)

The Photodetector Array Camera and Spectrometer (PACS), on board the Herschel Space Observatory, is designed for imaging and spectroscopy in the wavelength region between 60 and 210 gm. This paper reports ... [more ▼]

The Photodetector Array Camera and Spectrometer (PACS), on board the Herschel Space Observatory, is designed for imaging and spectroscopy in the wavelength region between 60 and 210 gm. This paper reports the design of the grating cryogenic mechanism of the PACS spectrometer and its remote controller (DEC/MEC) located on the outside of the Herschel cryostat. The PACS grating shall be capable of accurate positioning (4 arcsec) within a large angular stroke (40 arcdeg) in cryogenic environment (4.2 K). Technologies of actuators, position sensors, pivots, dry lubricants, servo-control and cryogenic test set-up are presented. At the other end of the Herschel 10-meter high-impedance cryogenic harness, the DEC/MEC consists of DSP processor-based electronics that control and synchronise the cold focal plane mechanisms and infrared detector arrays. The DEC/MEC operates an on board software running under a real-time operating system. Technologies involved in the control electronics are discussed and correlated to validation tests conducted with actual hardwares. [less ▲]

Detailed reference viewed: 96 (18 ULg)
Full Text
Peer Reviewed
See detailPhase-resolved X-ray and optical spectroscopy of the massive binary HD 93403
Rauw, Grégor ULg; Vreux, Jean-Marie ULg; Stevens, I. R. et al

in Astronomy and Astrophysics (2002), 388(2), 552-562

We report the first results of a campaign aimed at the study of early-type binaries with the XMM-Newton observatory. Phase-resolved EPIC spectroscopy of the eccentric binary HD93403 reveals a clear ... [more ▼]

We report the first results of a campaign aimed at the study of early-type binaries with the XMM-Newton observatory. Phase-resolved EPIC spectroscopy of the eccentric binary HD93403 reveals a clear orbital modulation of the X-ray luminosity as a function of the orbital phase. Below 1.0 keV, the observed X-ray flux is modulated by the opacity of the primary wind. Above 1.0 keV, the observed variation of the X-ray flux is roughly consistent with a 1/r dependence expected for an adiabatic colliding wind interaction. HD93403 appears less overluminuous in X-rays than previously thought and a significant fraction of the total X-ray emission arises probably within the winds of the individual components of the binary. Optical monitoring of the system reveals strong variability of the He II lambda 4686 and Halpha line profiles. The He II lambda 4686 line displays a broad asymmetrical emission component which is found to be significantly stronger between phases 0.80 and 0.15 than around apastron. This suggests that part of the emission arises in the interaction region and most probably in the trailing arm of a shock cone wrapped around the secondary. Some absorption lines of the secondary's spectrum display equivalent width variations reminiscent of the so-called Struve-Sahade effect. The differences in behaviour between individual lines suggest that the temperature may not be the only relevant parameter that controls this effect. [less ▲]

Detailed reference viewed: 6 (0 ULg)
See detailThe IMAGE mission (NASA) : design, test and results from the far UV spectrographic Imager
Habraken, Serge ULg; Renotte, Etienne ULg; Jamar, Claude ULg et al

in Space scientific research in Belgium (Space Sciences) (2002)

Detailed reference viewed: 22 (7 ULg)
Peer Reviewed
See detailIon outflow observed by IMAGE: Implications for source regions and heating mechanisms
Fuselier, S. A.; Ghielmetti, A. G.; Moore, T. E. et al

in Geophysical Research Letters (2001), 28

Images of the Earth's proton aurora from the IMAGE spacecraft on 8 June 2000 indicate a temporally and spatially isolated ionospheric response to a shock that impinged on the Earth's magnetopause ... [more ▼]

Images of the Earth's proton aurora from the IMAGE spacecraft on 8 June 2000 indicate a temporally and spatially isolated ionospheric response to a shock that impinged on the Earth's magnetopause. Sometime after this ionospheric response, the Low Energy Neutral Atom imager on IMAGE detected enhanced ionospheric outflow. The time delay between the ionospheric response and the enhanced outflow is consistent with the travel time of ~30 eV neutral Oxygen (created by charge exchange of outflowing O[SUP]+[/SUP] with the exosphere) from the low altitude ionosphere to the spacecraft. The prompt ionospheric outflow implies that the shock deposited sufficient energy in the topside ionosphere near or above the O[SUP]+[/SUP] exobase to initiate the outflow. [less ▲]

Detailed reference viewed: 6 (0 ULg)
See detailStellar calibration of the WIC and SI imagers and the GEO photometers on IMAGE/FUV
Gladstone, G. R.; Mende, S. B.; Frey, H. U. et al

Poster (2000, December)

Detailed reference viewed: 16 (1 ULg)
Full Text
Peer Reviewed
See detailFar ultraviolet imaging from the IMAGE spacecraft. 1. System design
Mende, S. B.; Heetderks, H.; Frey, H. U. et al

in Space Science Reviews (2000), 91

Direct imaging of the magnetosphere by the IMAGE spacecraft will be supplemented by observation of the global aurora, the footprint of magnetospheric regions. To assure the simultaneity of these ... [more ▼]

Direct imaging of the magnetosphere by the IMAGE spacecraft will be supplemented by observation of the global aurora, the footprint of magnetospheric regions. To assure the simultaneity of these observations and the measurement of the magnetospheric background neutral gas density, the IMAGE satellite instrument complement includes three Far Ultraviolet (FUV) instruments. In the wavelength region 120-190 nm, a downward-viewing auroral imager is only minimally contaminated by sunlight, scattered from clouds and ground, and radiance of the aurora observed in a nadir viewing geometry can be observed in the presence of the high-latitude dayglow. The Wideband Imaging Camera (WIC) will provide broad band ultraviolet images of the aurora for maximum spatial and temporal resolution by imaging the LBH N_2 bands of the aurora. The Spectrographic Imager (SI), a monochromatic imager, will image different types of aurora, filtered by wavelength. By measuring the Doppler-shifted Ly-alpha, the proton-induced component of the aurora will be imaged separately. Finally, the GEO instrument will observe the distribution of the geocoronal emission, which is a measure of the neutral background density source for charge exchange in the magnetosphere. The FUV instrument complement looks radially outward from the rotating IMAGE satellite and, therefore, it spends only a short time observing the aurora and the Earth during each spin. Detailed descriptions of the WIC, SI, GEO, and their individual performance validations are discussed in companion papers. This paper summarizes the system requirements and system design approach taken to satisfy the science requirements. One primary requirement is to maximize photon collection efficiency and use efficiently the short time available for exposures. The FUV auroral imagers WIC and SI both have wide fields of view and take data continuously as the auroral region proceeds through the field of view. To minimize data volume, multiple images are taken and electronically co-added by suitably shifting each image to compensate for the spacecraft rotation. In order to minimize resolution loss, the images have to be distortion-corrected in real time for both WIC and SI prior to co-adding. The distortion correction is accomplished using high speed look up tables that are pre-generated by least square fitting to polynomial functions by the on-orbit processor. The instruments were calibrated individually while on stationery platforms, mostly in vacuum chambers as described in the companion papers. Extensive ground-based testing was performed with visible and near UV simulators mounted on a rotating platform to estimate their on-orbit performance. The predicted instrument system performance is summarized and some of the preliminary data formats are shown. [less ▲]

Detailed reference viewed: 33 (8 ULg)
Full Text
Peer Reviewed
See detailFar ultraviolet imaging from the IMAGE spacecraft. 3. Spectral imaging of Lyman-alpha and OI 135.6 nm
Mende, S. B.; Heetderks, H.; Frey, H. U. et al

in Space Science Reviews (2000), 91

Two FUV Spectral imaging instruments, the Spectrographic Imager (SI) and the Geocorona Photometer (GEO) provide IMAGE with simultaneous global maps of the hydrogen (121.8 nm) and oxygen 135.6 nm ... [more ▼]

Two FUV Spectral imaging instruments, the Spectrographic Imager (SI) and the Geocorona Photometer (GEO) provide IMAGE with simultaneous global maps of the hydrogen (121.8 nm) and oxygen 135.6 nm components of the terrestrial aurora and with observations of the three dimensional distribution of neutral hydrogen in the magnetosphere (121.6 nm). The SI is a novel instrument type, in which spectral separation and imaging functions are independent of each other. In this instrument, two-dimensional images are produced on two detectors, and the images are spectrally filtered by a spectrograph part of the instrument. One of the two detectors images the Doppler-shifted Lyman-alpha while rejecting the geocoronal `cold' Ly-alpha, and another detector images the OI 135.6 nm emission. The spectrograph is an all-reflective Wadsworth configuration in which a grill arrangement is used to block most of the cold, un-Doppler-shifted geocoronal emission at 121.567 nm. The SI calibration established that the upper limit of transmission at cold geocoronal Ly-alpha is less than 2%. The measured light collecting efficiency was 0.01 and 0.008 cm^2 at 121.8 and at 135.6 nm, respectively. This is consistent with the size of the input aperture, the optical transmission, and the photocathode efficiency. The expected sensitivity is 1.8x10^-2 and 1.3x10^-2 counts per Rayleigh per pixel for each 5 s viewing exposure per satellite revolution (120 s). The measured spatial resolution is better than the 128x128 pixel matrix over the 15 degx15 deg field of view in both wavelength channels. The SI detectors are photon counting devices using the cross delay line principle. In each detector a triple stack microchannel plate (MCP) amplifies the photo-electronic charge which is then deposited on a specially configured anode array. The position of the photon event is measured by digitizing the time delay between the pulses detected at each end of the anode structures. This scheme is intrinsically faster than systems that use charge division and it has a further advantage that it saturates more gradually at high count rates. The geocoronal Ly-alpha is measured by a three-channel photometer system (GEO) which is a separate instrument. Each photometer has a built in MgF_2 lens to restrict the field of view to one degree and a ceramic electron multiplier with a KBr photocathode. One of the tubes is pointing radially outward perpendicular to the axis of satellite rotation. The optic of the other two subtend 60 deg with the rotation axis. These instruments take data continuously at 3 samples per second and rely on the combination of satellite rotation and orbital motion to scan the hydrogen cloud surrounding the earth. The detective efficiencies (effective quantum efficiency including windows) of the three tubes at Ly-alpha are between 6 and 10%. [less ▲]

Detailed reference viewed: 25 (5 ULg)
Full Text
Peer Reviewed
See detailObservations of Coronal Structures Above an Active Region by EIT and Implications for Coronal Energy Deposition
Neupert, W. M.; Newmark, J.; Delaboudinière, J.-P. et al

in Solar Physics (1998), 183

Solar EUV images recorded by the EUV Imaging Telescope (EIT) on SOHO have been used to evaluate temperature and density as a function of position in two largescale features in the corona observed in the ... [more ▼]

Solar EUV images recorded by the EUV Imaging Telescope (EIT) on SOHO have been used to evaluate temperature and density as a function of position in two largescale features in the corona observed in the temperature range of 1.0-2.0MK. Such observations permit estimates of longitudinal temperature gradients (if present) in the corona and, consequently, estimates of thermal conduction and radiative losses as a function of position in the features. We examine two relatively cool features as recorded in EIT's Feix/x (171Å) and Fexii (195Å) bands in a decaying active region. The first is a long-lived loop-like feature with one leg, ending in the active region, much more prominent than one or more distant footpoints assumed to be rooted in regions of weakly enhanced field. The other is a near-radial feature, observed at the West limb, which may be either the base of a very high loop or the base of a helmet streamer. We evaluate energy requirements to support a steady-state energy balance in these features and find in both instances that downward thermal conductive losses (at heights above the transition region) are inadequate to support local radiative losses, which are the predominant loss mechanism. The requirement that a coronal energy deposition rate proportional to the square of the ambient electron density (or pressure) is present in these cool coronal features provides an additional constraint on coronal heating mechanisms. [less ▲]

Detailed reference viewed: 33 (8 ULg)
Full Text
Peer Reviewed
See detailEIT and LASCO Observations of the Initiation of a Coronal Mass Ejection
Dere, K. P.; Brueckner, G. E.; Howard, R. A. et al

in Solar Physics (1997), 175

We present the first observations of the initiation of a coronal mass ejection (CME) seen on the disk of the Sun. Observations with the EIT experiment on SOHO show that the CME began in a small volume and ... [more ▼]

We present the first observations of the initiation of a coronal mass ejection (CME) seen on the disk of the Sun. Observations with the EIT experiment on SOHO show that the CME began in a small volume and was initially associated with slow motions of prominence material and a small brightening at one end of the prominence. Shortly afterward, the prominence was accelerated to about 100 km s[SUP]-1[/SUP] and was preceded by a bright loop-like structure, which surrounded an emission void, that traveled out into the corona at a velocity of 200 400 km s[SUP]-1[/SUP]. These three components, the prominence, the dark void, and the bright loops are typical of CMEs when seen at distance in the corona and here are shown to be present at the earliest stages of the CME. The event was later observed to traverse the LASCO coronagraphs fields of view from 1.1 to 30 Ro. Of particular interest is the fact that this large-scale event, spanning as much as 70 deg in latitude, originated in a volume with dimensions of roughly 35" (2.5 x 10[SUP]4[/SUP] km). Further, a disturbance that propagated across the disk and a chain of activity near the limb may also be associated with this event as well as a considerable degree of activity near the west limb. [less ▲]

Detailed reference viewed: 39 (11 ULg)
Full Text
Peer Reviewed
See detailOptical design of the FUV spectrographic imager for the IMAGE mission
Habraken, Serge ULg; Jamar, Claude ULg; Rochus, Pierre ULg et al

in Society of Photo-Optical Instrumentation Engineers (SPIE) Conference Series (1997)

This paper describes the original concept and the optical design of the IMAGE mission FUV spectrographic imager (SI). The instrument goal is to spectrally separate and image the electron and proton ... [more ▼]

This paper describes the original concept and the optical design of the IMAGE mission FUV spectrographic imager (SI). The instrument goal is to spectrally separate and image the electron and proton auroras. A 30 angstrom (3 nm) spectral resolution is required to isolate the electron auroras (1356 angstrom). The proton aurora imaging requires to efficiently mask the geocoronal Lyman-alpha line (1216 angstrom), in order to image the Doppler shifted Lyman-alpha light (1217 - 1223 angstrom). A classical SI combines a telescope with a spectrometer. Our SI is consisting of a reverse combination: (1) a multi-slits Wadsworth monochromator designed to spectrally isolate the two bandwidths (electrons and protons auroras), (2) a two mirror imager with a crossed delay line detector producing the final imaging on each spectral channel. [less ▲]

Detailed reference viewed: 49 (9 ULg)
Full Text
Peer Reviewed
See detailFirst Results from EIT
Clette, Frédéric; Delaboudiniere, J.-P.; Artzner, G. E. et al

in 1st Advances in Solar Physics Euroconference. Advances in Physics of Sunspots (1997)

The Extreme-UV Imaging telescope has already produced more than 15000 wide-field images of the corona and transition region, on the disk and up to 1.5R_o above the limb, with a pixel size of 2.6\arcsec ... [more ▼]

The Extreme-UV Imaging telescope has already produced more than 15000 wide-field images of the corona and transition region, on the disk and up to 1.5R_o above the limb, with a pixel size of 2.6\arcsec. By using four different emission lines, it provides the global temperature distribution in the quiet corona, in the range 0.5 to 3*E(6) K. Its excellent sensitivity and wide dynamic range allow unprecedented views of low emission features, even inside coronal holes. Those so-called ``quiet'' regions actually display a wide range of dynamical phenomena, in particular at small spatial scales and at time scales going down to only a few seconds, as revealed by all EIT time sequences of full- or partial-field images. The initial results presented here demonstrate the importance of this wide-field imaging experiment for a good coordination between SOHO and ground-based solar telescopes, as well as for science planning. [less ▲]

Detailed reference viewed: 19 (4 ULg)
Full Text
Peer Reviewed
See detailEIT: Extreme-Ultraviolet Imaging Telescope for the SOHO Mission
Delaboudinière, J.-P.; Artzner, G. E.; Brunaud, J. et al

in Solar Physics (1995), 162

The Extreme-ultraviolet Imaging Telescope (EIT) will provide wide-field images of the corona and transition region on the solar disc and up to 1.5 Ro above the solar limb. Its normal incidence multilayer ... [more ▼]

The Extreme-ultraviolet Imaging Telescope (EIT) will provide wide-field images of the corona and transition region on the solar disc and up to 1.5 Ro above the solar limb. Its normal incidence multilayer-coated optics will select spectral emission lines from Fe IX (171 Å), Fe XII (195 Å), Fe XV (284 Å), and He II (304 Å) to provide sensitive temperature diagnostics in the range from 6 × 10[SUP]4[/SUP] K to 3 × 10[SUP]6[/SUP] K. The telescope has a 45 x 45 arcmin field of view and 2.6 arcsec pixels which will provide approximately 5-arcsec spatial resolution. The EIT will probe the coronal plasma on a global scale, as well as the underlying cooler and turbulent atmosphere, providing the basis for comparative analyses with observations from both the ground and other SOHO instruments. This paper presents details of the EIT instrumentation, its performance and operating modes. [less ▲]

Detailed reference viewed: 50 (6 ULg)
See detailHigh-latitude ion transport and energetic explorer (HI-LITE): a mission to investigate ion outflow from the high-latitude ionosphere
Smith, Mark F; Herrero, Federico A; Hesse, Michael et al

in Society of Photo-Optical Instrumentation Engineers (SPIE) Conference Series (1993, July 01)

The proposed HI-LITE Explorer will investigate the global ion outflow from the high-latitude ionosphere, its relationship to auroral features, and the consequences of this outflow on magnetospheric ... [more ▼]

The proposed HI-LITE Explorer will investigate the global ion outflow from the high-latitude ionosphere, its relationship to auroral features, and the consequences of this outflow on magnetospheric processes. The unique nature of the HI-LITE Explorer images will allow temporal and spatial features of the global ion outflow to be determined. The mission's scientific motivation comes from the fundamental role high-latitude ionospheric ions play in the dynamics of the solar wind driven magnetospheric-ionospheric system. These outflows are a major source of plasma for the magnetosphere and it is believed they play an important role in the triggering of substorms. In addition this paper describes the HI-LITE spacecraft and instruments. [less ▲]

Detailed reference viewed: 12 (1 ULg)