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Observations of discrete sources at 3-cm wavelength using a maser*

Published online by Cambridge University Press:  14 August 2015

L. E. Alsop ,
J. A. Giordmaine ,
C. H. Mayer  and
C. H. Townes
L. E. Alsop
Affiliation:
Columbia University, New York, U.S.A.
J. A. Giordmaine
Affiliation:
Columbia University, New York, U.S.A.
C. H. Mayer
Affiliation:
U.S. Naval Research Laboratory, Washington, D.C., U.S.A.
C. H. Townes
Affiliation:
Columbia University, New York, U.S.A.

Extract

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The new types of low-noise radio-frequency amplifiers now under development hold great promise for improving and extending radio astronomical observations. A solid-state maser, designed and built at Columbia University, has been used with the U.S. Naval Research Laboratory's 50-foot reflector since 1958 April. The maser is the 3-level type [1], with ruby [2] as the paramagnetic medium. Initially, an rms radiometer output fluctuation of about 0.1 °K was realized with a 5s output time constant. Subsequent improvements of the maser and of the associated circuitry have made it possible to observe with an rms output fluctuation of 0.04 °K for a 5s output time constant. These figures represent improvement factors of about 5 and 13 respectively over the radiometer without the maser. These significant improvements in sensitivity have made possible continuum observations which could not previously have been made with the NRL apparatus except by unwieldy averaging techniques.

Type
Part I: Moon and Planets
Information
Symposium - International Astronomical Union , Volume 9: Paris Symposium on Radio Astronomy , 1959 , pp. 69 - 74
Copyright
Copyright © Stanford University Press 1959 

References

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