Michael Morag edited Experimental Setup.tex  about 10 years ago

Commit id: 11d31c1c6a188e2d723b955e45fac4a926860caa

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\section{Experimental Setup}  The plasma was created by an inductively coupled RF source operating at a power of 120 W with $4\times 10^{-4}$ Torr Argon as the working gas. A voltage sweep was put across a Langmuir probe 70 cm from the RF source 1.3 ms into the afterglow and over a 101 $\mu s$ range. A magnetic field was applied to the device through the use of two sets of four coaxial magnets created through the use of 25.4A and 63.0A currents laid out around the device and resulting in a radially symmetric magnetic field through the device, averaging to 60 Gauss along the length. Whistler waves were generated in the plasma using a wave form generating antenna, set to 40 MHz for the experiment with data taken in a plane and set to 9 separate varying frequencies from 40 MHz to 120 MHz, each 10 MHz apart. A B-dot probe was used to measure the oscillations in the magnetic field due to the wave over a range of 70-90cm from the RF source axially and -15 degrees to 15 degrees radially for the set taken in a plane and varying axial lengths for the linear data set such that 10 data points were taken per wavelength of the measured wave. The B-dot probe used in this experiment consists of 3 sets of loops, each with a single(copper?)  wire sheathed by a insulating  ceramic exterior (I know he asked us why its surrounded by ceramic. Do we have an answer for him?). exterior.  The loops are positioned orthonormal to one another with $\hat{z}$ along the central axis, and $\hat{x}$, $\hat{y}$, representing horizontal and vertical axes respectivily. When the loop of wire is in the normal direction with respect to a magnetic field, a change in magnetic field will induce a voltage by Faraday's law.