Abstract
The performance of a synchronous detection system using a cooled phototube (type S1 cathode) is described. Detailed measurements including those using an ultralinear semiconductor photosource indicate that the system responds linearly within 1% per decade of incident flux variation. A tunnel diode discriminator increases the signal-to-noise ratio by a factor of up to 5. The over-all sensitivity obtained is ∼3×103 photons/sec or 5×10−16 W at 0.8 μ wavelength (phototube temperature −78°C). A field effect transistor amplifier with a relatively fast (390 cps) chopping rate is employed. In a spectrometer application in which the detection system is used in conjunction with a conventional monochromator (0.35 transmission, f/8 optics, and 0.005 μ/mm dispersion), a system sensitivity threshold of 4×10−12 W/cm2 μ sr is obtained at 0.8 μ wavelength.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
