Chris Spencer edited Experimental Setup.tex  about 10 years ago

Commit id: 39e4a5b356d5de1b53d188d1ad117eaf5637d741

deletions | additions      

       

\section{Experimental Setup}  The plasma was created by an inductively coupled RF source operating at a power of 120W with $4\times 10^{-4}$ torr Argon as the working gas. A voltage sweep was put across a langmuir probe 70cm from the RF source 1.3ms 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 as shown in \textbf{figure 1} and resulting in a radially symmetric magnetic field through the device as measured in \textbf{table 1}, averaging to about 60G along the length. Whistler waves were generated in the plasma using a wave form generating antenna, set to 40MHz for the experiment with data taken in a plane and set to 9 separate varying frequencies from 40MHz to 120MHz, each 10MHz 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. wave.The B-dot probe used in this experiment consists of 6 faces of a wire of one loop in a cube orientation.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 faradays law.