Schematic view of the Mass instrument on the Wind spacecraft adapted from Zurbuchen et al. (Ref. 19). An electrostatic deflection system is combined with a TOF unit with a carbon foil and two MCP detectors which are sensitive to both charged particles and EUV radiation.
Definition of incident and reflected photon directions. and measure the photon incident direction; and measure the photon scattered direction. and are unit vectors corresponding to the incident and scattered directions, respectively. The -axis is defined as the unit vector normal to the scattering surface.
Side view of the Wind/Mass ESA system with treated surfaces. This geometry provides the basis for the simulations performed in this paper.
SIMION 3D model of Wind/Mass ESA with exit plates and photon detector. This geometry is identical to the experimental test setup to which the simulations are compared. The coordinate axis of the entrance aperture is shown in the front view.
Calculated BRDF for sandblasted aluminum using the Li–Torrance model and surface scattering parameters from Zurbuchen et al. (Ref. 19). Curves are shown for radiation scattered in the plane of incidence for various values of incident angle . Specular reflection becomes increasingly important at higher angles of incidence as shown in the and curves. For lower angles of incidence, specular reflection is negligible causing no visible specular peaks to appear in the and curves.
(a) Photon transmission as a function of photon entrance coordinate for the aluminum mirror simulation (See Fig. 4). (b) The photon intensity is binned according to entrance height. Each peak corresponds to a certain number of reflections a photon much undergo before it reaches the detector. The number of reflections corresponding to each peak is labeled. The dashed vertical lines highlight the passbands of photons at the entrance aperture.
Same format as Fig. 6 but for sandblasted aluminum case.
EUV suppression factor as a function of Wind/Mass analyzer electrode spacing for aluminum mirror and sandblasted aluminum simulations. Error bars are shown for the sandblasted aluminum. Convergence errors are small enough for the aluminum mirror case so that error bars are not visible.
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