The solar high-resolution imager - coronagraph LYOT mission

Vial, J. C.; Song, Xueyan; Lemaire, Philippe; Gabriel, A. H.; Delaboudinière, J. P.; Bocchialini, K.; Koutchmy, S.; Lamy, Philippe; Mercier, Raymond; Ravet, M. F.; Auchère, F.

doi:10.1117/12.460291

Cited by 5 publications

(2 citation statements)

References 19 publications

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“…In applications of solar physics, the emission lines of Fe-IX (l 5 17.1 nm), Fe-XII (l 5 19.5 nm), Fe-XV (l 5 28.4 nm) and He-II (l 5 30.4 nm) can be selected as imaging of solar corona [1][2][3][4][5][6][7][8][9]. Due to the strong absorption of most materials in an extreme ultraviolet (EUV) region, the optical system at normal incidence requires a high reflectivity multilayer mirror.…”

Section: Introductionmentioning

confidence: 99%

SiC/Mg multilayer reflective mirror for He-II radiation at 30.4 nm and its thermal stability

Zhu

Zhang

et al. 2008

Front. Optoelectron. China

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In applications of solar physics, extreme ultraviolet imaging of solar corona by selecting the He-II (l 5 30.4 nm) emission line requires high reflectivity multilayer mirrors. Some material combinations were studied to design the mirrors working at a wavelength of 30.4 nm, including SiC/Mg, B on optimization of the largest reflectivity and the narrowest width for the multilayer mirror, a SiC/Mg material combination was selected as the mirror and fabricated by a magnetron sputtering system. The layer thicknesses of the SiC/Mg multilayer were measured by an X-ray diffractometer. Reflectivities were then measured on beamline U27 at the National Synchrotron Radiation Laboratory (NSRL) in Hefei, China. At a wavelength of 30.4 nm, the measured reflectivity is as high as 38.0%. Furthermore, a series of annealing experiments were performed to investigate the thermal stability of the SiC/Mg multilayer.

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Section: Introductionmentioning

confidence: 99%

SiC/Mg multilayer reflective mirror for He-II radiation at 30.4 nm and its thermal stability

Zhu

Zhang

et al. 2008

Front. Optoelectron. China

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“…Consequently, a number of future instruments that are currently being developed would include polarimeters designed to measure circular and linear polarization of UV lines: e.g. SUMI (Solar Ultraviolet Magnetograph Investigation: Porter et al 2003), and LYOT (LYman Orbiter Telescope, solar highresolution imager -coronagraph mission, Vial et al 2003). The development of these new instruments requires numerical simulations that predict the behavior and the order of magnitude of the sensitivity of the Stokes parameters to the velocity field.…”

Section: Introductionmentioning

confidence: 99%

Doppler redistribution of anisotropic radiation and resonance polarization in moving scattering media

Sahal‐Bréchot¹,

Raouafi

2005

A&A

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The present paper puts the Doppler redistribution theory of anisotropic radiation and resonance polarization in moving scattering media into a predictive application following Sahal-Bréchot et al. (1998, A&A, 340, 579; P II ), using the example of the O vi 1032 Å line of the corona.Numerical results are presented for different heights over the limb compatible with observations of different instruments on SOHO (SUMER, CDS, UVCS) but far from coronal holes in order to avoid inhomogeneities of the transition zone incident radiation. The orders of magnitude of our numerical results confirm the theoretical predictions of P II and show that interpretation of polarimetric data of the O vi 1032 Å line of the corona, associated to the shift and the Doppler-dimming effect, offers a powerful diagnostic method of the complete velocity field vector, provided that the partial anisotropy of the incident radiation field be taken into account. These results also explain the precision of the diagnostic of interpretation polarimetric observations achieved by the ultraviolet spectrometer SUMER in the south polar coronal hole at 270 above the solar limb; e.g. the solar wind acceleration region.

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