Photovoltaic indium antimonide detectors have been operated at temperatures =77 K with sufficiently low background radiation levels that Johnson noise limited performance is realized. Under such conditions the noise equivalent power (NEP) is completely determined by the detector operating temperature, resistance, and quantum efficiency. Optimization of these parameters in the manufacture of commercially available detectors has led to 5-mum NEP's as low as 10(-15) W. The particular preamplifier is critical to the achievement of Johnson noise limited operation and is described in detail.
From observations made at Kitt Peak the true central intensities of 40 Fraunhofer lines distributed between ,~2 3083-7699, for the center of the solar disk, are derived and given in tabular form. The paper includes a description of the optical system -telescope and spectrograph. The methods of observation and reduction of the data are discussed.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.