phy-4660/xrd/report/report.tex

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2017-04-13 08:44:22 +00:00
\documentclass[11pt,letterpaper]{article}
%\usepackage{aas_macros}
\usepackage{biblatex}
\usepackage{graphicx}
\usepackage[margin=1.in,centering]{geometry}
\usepackage{hyperref}
\usepackage{caption}
\usepackage[export]{adjustbox}
\usepackage{float}
\usepackage{gensymb}
\bibliography{/home/caes/wmu/phy-4660/adv_lab.bib}
\begin{document}
\newcommand{\FpaO}{$^{19}\textrm{F(p,}\alpha)^{16}\textrm{O}$}
\newcommand{\LipaHe}{$^7\textrm{Li(p,}\alpha)^4\textrm{He}$}
%\newcommand{}$^7\textrm{Li(p,}\alpha)^4\textrm{He}$ reaction.\\
\title{Lab 5: X-Ray Diffractometer}
\author{Otho Ulrich, Mike Pirkola, Jacob Burke, Andrew Messecar}
\maketitle
\begin{abstract}
Western Michigan University's new X-Ray Diffractometer is used to probe four materials. The lattice contant is computed for an NaCl sample. For three amorphous samples -- wood, grease, and SOMETHING -- the average distance between atoms is computed.
\end{abstract}
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\section{Introduction: Bragg Diffraction and Materials Science}
\label{sec:intro}
packing fraction for salt, 60\% is about good
densities of plastic are all around 2
pick carbon, with occassional oxygens, so using just carbon you get ~$2grams/cm^3$
Bragg diffraction of X-rays is a useful method for characterising the atomic and molecular structure of materials. Many mechanical and electric properties are functions of the structures that constitute materials. Bragg diffraction uses the wave theory of electromagnetic radiation to predict how X-Rays will interact with the atomic lattice of a crystal. The spacing between atoms can be measured by inference, and the average spacing between atoms is often called the ``lattice constant''.
We attempt to compute the lattice constant from an X-ray diffractometer reading of a sample of NaCl, or common salt. NaCl forms a cubic crystal structure, so it has a single lattice constant, and this is computed from the diffraction pattern and compared to known values. Three amorphous samples are also analyzed: plastic of an unknown type; grease; and plywood. These materials are not expected to have rigid crystal structures, but the average spacing between atoms can still be ascertained from the diffraction pattern.
\subsection{X-Ray Diffractometer}
\label{subsec:diffrator}
An Empyrean X-Ray diffractometer by PANalytical \cite{empyrean} was used to collect a diffraction pattern from each sample. In this machine, an X-ray source emits onto a material sample, and a detector records X-rays diffracted at the angle of incidence; see Figure~\ref{fig:diffractometer}. X-Rays are created by accelerating electrons toward a copper anode (Figure~\ref{fig:xraysource}). The X'Celerator detector is a
\begin{figure}
\center
\includegraphics[width=3in]{empyrean_sample.jpg}
\includegraphics[width=3in]{empyrean_scanners.pdf}
\caption{The PANalytical Empyrean X-Ray diffractometer. A sample in placed in the center bin. X-Rays are generated in the arm on the left, diffracted by the sample at the center, and detected at an angle $\theta$ by the X'Celerator in the arm on the right. Each scan ran through $\theta = \{5\degree .. 45\degree\}$.}
\label{fig:diffractometer}
\end{figure}
\begin{figure}
\center
[A]\includegraphics[width=3in]{xraytube.png}
[B]\includegraphics[width=3in]{Copper_K_Rontgen.png}
\caption{X-Rays are generated when collisions with accelerated electrons knock electrons in the copper atoms of the anode out of the K shell. When the electrons fall back to the K shell, X-rays are emitted with energies indicated in [B]. These energy values are important for predicting the X-Ray diffraction pattern from Bragg diffraction. \cite{advlabxrd} \cite{xraytubephoto}}
\label{fig:xraysource}
\end{figure}
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\section{Results}
\label{sec:results}
%─────────────
\section{Conclusion}
\label{sec:conclusion}
\printbibliography
\end{document}