Intermediate & Advanced Laboratory

"Experiment is the sole judge of scientific 'truth'"
- Richard Feynman -

Langmuir Probe

Plasma (oh, my!)
Happy indeed is the scientist who not only has the pleasures which I have enumerated, but who also wins the recognition of fellow scientists and of the mankind which ultimately benefits from his endeavors.

-Irving Langmuir, inventor of the Langmuir Probe, also coined the term "plasma"

In this experiment you will use a Langmuir probe to investigate several defining features of a plasma: the electron and ion densities, plasma potential, and electron velocity as they depend on the plasma density in general.

The vacuum tube. Notice the solid metal cathode (annulus), the trigger anode ring, and the long anode passing through their centers that will be used as the Langmuir probe.

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The Keithly piccoameter sits atop the variable voltage source. LabView will control the voltage source whilist reading the meter.

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The Heathkit high voltage source. You will use this to create the plasma.

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