1 Abstract—Dust particles obtain a charge due to the absorption of free electrons and ions from their surroundings. When immersed in a radio frequency discharge, these dust agglomerates may cause changes to the local plasma. In this experiment the optical emission of the discharge was analyzed. Since emission is due to relaxation of atoms in excited states caused by electron impact excitation, the altered emission of the plasma traces changes in the electron density and temperature within the plasma. These results are compared with a two dimensional fluid model to determine accuracy within the experiment. Index Terms—radio frequency discharge, GEC reference cell, dusty plasma, fluid model simulation. I. INTRODUCTION Dust particles are common contaminants in plasma ranging in size from 10nm to 1mm. They can be found in plasmas contained in technological equipment and have been found to be potentially harmful as in the case of beryllium/carbon plasma facing components (PFC’s) [1]. Not only have these particles been observed within the laboratory, but they have also been analyzed within astrophysical and atmospheric conditions [2, 3], and have the potential to be important components within these systems. Thus several experiments have been This work was supported in part by the National Science Foundation through the Research Experience of Undergraduates program. Erin Middlemas is with Baylor University, and was a participant in the REU program (e-mail: zemm16@goldmail.etsu.edu ). Autumn Paro is with Baylor University, and was a participant in the REU program (SR_Autumn_Paro@Baylor.edu). Victor Land is with the Center for Astrophysics, Space Physics, and Engineering Research, Baylor University, Waco, TX 76798 (e-mail: victor_land@baylor.edu ). Angela Douglass is with the Center for Astrophysics, Space Physics, and Engineering Research, Baylor University, Waco, TX 76798 (email: angela_douglass@baylor.edu ). Lorin S. Matthews is with the Physics department at Baylor University, Waco, TX 76798 (email: Lorin_Matthews@baylor.edu ). Truell W. Hyde is with the Center for Astrophysics, Space Physics & Engineering Research, and is Vice Provost of Research at Baylor University, One Bear Place #9731, Waco, TX. 76798 (email: Truell_Hyde@baylor.edu). carried out to study the characteristics of these dust particles and their effects on plasma more carefully. Procedures such as thermophoresis involving electrode heating on a radio frequency discharge [4], studying dust agglomerates on the rings of Saturn [2], and studying the formation of dust within an rf discharge [5] have all been carried out to analyze the properties of such dust agglomerates. Plasmas are becoming more and more essential components within technology. Studying the effects of dust on plasmas, therefore, has become necessary. Studies such as analyzing the formation of dust particles within certain radio frequencies [6], and simulations such as particle-particle particle- mesh simulations [7] and two-dimensional fluid models [8] have been used to learn more about these complex plasmas. In this experiment the effects of dust particles on radio frequency discharges was focused on by observing changes within emission for different amounts of particles introduced into the plasma. Although electronic data measuring the electric potential, current, and derivative signals were measured also, this paper will focus on results from images taken with the charge-coupled device (CCD) camera. A two-dimensional fluid model was employed to compare with experimental results. II. THEORY What distinguishes plasma from other states of matter is the ionization of particles due to a high amount of energy given to the system. This energy knocks electrons off neutral atoms, creating an environment containing neutral atoms, electrons, and ions [9]. When the electrons collide with neutral atoms, the atom enters an excited state. When the atom de-excites, a photon is released creating emission. From a previous experiment Effects of dust on the optical emission of rf discharges: Experiment and simulation Erin Middlemas, Autumn Paro, Victor Land, Angela Douglass, Lorin Matthews, and Truell Hyde, Center for Astrophysics, Space Physics, and Engineering Research, Baylor University, Waco, TX 76798-7316, USA