Date

6-2011

Degree Name

BS in Physics

Department

Physics Department

Advisor(s)

Tom Bensky

Abstract

The goal of this work is to use a Neodymium-Doped Yttrium Aluminum Garnet (Nd:YAG) Laser, spectrometer, and computer to create a Laser Induced Breakdown Spectroscopy (LIBS) system. LIBS utilizes a focused, high-powered, pulsed laser whose peak electric field ionizes materials at the beam focal point, creating localized plasma. The plasma state includes broken molecular bonds, atom/electron-ionization, and excited electrons, which on the macroscopic level is a loud “snap” and a bright spark. In this project, a fiber optic cable is used to capture light emitted from the spark, and direct it into a spectrometer which tallies the number of photons at each wavelength, resulting in a characteristic spectrum of the light produced. Because each photon corresponds to a specific energy transition within the plasma, the spectrum can be used to determine the composition of the material and relative abundance of elements. With careful equipment synchronization, we were able to assemble and test a working computer-controlled LIBS system. Data is presented for various samples including the atmosphere and metallic coin surfaces.

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