The optical constants of electron-beam evaporated boron from 6.8 to 900 eV were calculated through transmittance measurements of boron thin films deposited onto carbon-coated microgrids or LiF substrates in ultrahigh-vacuum conditions. In the low-energy part of the spectrum the measurements were performed in situ on freshly deposited samples, whereas in the high-energy range the samples were exposed to the atmosphere before the measurements. The extinction coefficient was calculated directly from the transmittance data, and a Kramers-Kronig analysis that combined the current data with data from the literature was performed to determine the dispersive part of the index of refraction. Finally, two different sum-rule tests were performed that indicated the good consistency of the data.
The CARMENES instrument has been operational at the 3.5 m telescope of Calar Alto Observatory since January 2016. It consists of two cross-dispersedéchelle spectrographs covering the wavelength range from 0.52 to 1.71 µm. CARMENES is currently conducting a radial-velocity survey of more than 300 M dwarfs, with a sensitivity sufficient to detect terrestrial planets in their habitable zones. This survey has already yielded a comprehensive spectral atlas of 324 M dwarfs, and it is providing a wealth of diagnostic information on activity in cool stars. The CARMENES Survey data have confirmed a number of known M star planets, and revealed previously unknown planets of GJ 15 A, GJ 1148, and GJ 617 A. CARMENES data have also been used to determine the mass of the transiting planet K2-18 b, and to measure atomic and molecular absorption in planetary atmospheres through transit spectroscopy.
The transmittance of silicon monoxide films prepared by thermal evaporation was measured from 7.1 to 800 eV and used to determine the optical constants of the material. SiO films deposited onto C-coated microgrids in ultrahigh vacuum conditions were measured in situ from 7.1 to 23.1 eV. Grid-supported SiO films deposited in high vacuum conditions were characterized ex situ from 28.5 to 800 eV. At each photon energy, transmittance, and thickness data were used to calculate the extinction coefficient k. The obtained k values combined with data from the literature, and with interpolations and extrapolations in the rest of the electromagnetic spectrum provided a complete set of k values that was used in a Kramers–Kronig analysis to obtain the real part of the index of refraction, n. Two different sum-rule tests were performed that indicated good consistency of the data.
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