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U.S. Department of Energy
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Noise considerations in millimeter-wave spectrometers

Technical Report ·
DOI:https://doi.org/10.2172/6231691· OSTI ID:6231691
An improved version of a microwave spectrometer operating in the vicinity of 70 GHz is described. The spectrometer, which incorporates a Fabry-Perot resonator and superheterodyne detection for high sensitivity is designed for the detection of gaseous pollutants and other atmospheric constituents. The instrument is capable of detecting polar molecules with absorption coefficients as small as 2 x 10/sup -9/cm/sup -1/. For sulphur dioxide diluted in air, this sensitivity corresponds to a detection limit of 1.2 ppm without preconcentration and with a time constant of 1 second. Measurements and analysis of the noise contributions limiting the sentivity are presented.
Research Organization:
California Univ., Berkeley (USA). Lawrence Berkeley Lab.
DOE Contract Number:
W-7405-ENG-48
OSTI ID:
6231691
Report Number(s):
LBL-7294
Country of Publication:
United States
Language:
English