<title>Optical properties of 3D transition metals in the spectral interval of interest for discharge-pumped XUV lasers</title>

Focusing diffraction optics for orbital telescopes

“…An ideal combination of excitations of valence and core electrons makes Sc the most promising element for MISs designed for wavelengths lying within the 35−50 nm interval. The Sc−Si pair was identified as the best coating [57][58][59] in the analysis of absorption spectra and calculated optical constants [56].…”

“…The extension of sensitivity to E ∼ 200 keV is of particular interest, since several key nuclear transitions of radioactive elements produced in supernova explosions lie between 50 and 200 keV. For example, decays of 44 Ti (68 and 78 keV) and 56 Ni (158 keV) are of interest, since the production and ejection of 44 Ti are sensitive to the explosion mechanism, and the temporal evolution of intensity of the 56 Ni line is sensitive to the structure and dynamics of ejection [147].…”

“…It will focus photons in two energy bands simultaneously. Each of them will serve to fulfill one of the primary research objectives: the 800−900 keV band is expected to be used for examining nuclear lines of gamma radiation of type Ia supernovae (e.g., the 56 Co decay line at 847 keV), while the 450−530 keV band is proposed to be used for the study of electronpositron annihilation. Cu (111), Cu (200), Cu (220), Cu (222) (18 rings), and Ge (311) (2 rings) crystals are meant to cover the 800−900 keV band, while Cu (111), Cu (200) (14 rings), and Ge (111) (2 rings) should cover the 450−530 keV band [184].…”