2015 BFY II Abstract Detail Page

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Abstract Title: W34 - Noise Fundamentals, JN– Using Johnson-noise to measure the Boltzmann Constant
Abstract: Many instructors, and some students, have heard of Johnson-noise and shot noise in electric circuits, TeachSpin's apparatus provides a way to study both in detail in a trouble-free experimental arena.  Students can see electrical noise, and measure spectral noise density, right from its definition.  They can investigate, quantitatively, the dependence of Johnson noise on source resistance and bandwidth, as well as on temperature in the 77 – 350 K range using the Dewar flask and proprietary probe provided.  A measurement of Boltzmann's constant, to a precision of a few percent, is a by-product. Furthermore, quantitative measurements of the shot noise present in a photocurrent allow the measurement of the fundamental charge 'e' to similar precision.

Participants will:
• Follow a noise signal from birth to quantitative measurement
• Learn how noise density is defined and measured
• See the dependence of Johnson noise on source resistance
• Deduce a value for Boltzmann's constant from Johnson-noise data
Abstract Type: Workshop

Author/Organizer Information

Primary Contact: Barbara Wolff-Reichert
and Co-Presenter(s)
Jonathan Reichert, George Herold, David Van Baak, TeachSpin

Workshop Documents

Workshop Doc 1: Download the Workshop Doc 1
Workshop Doc 2: Download the Workshop Doc 2