Irina's edits

4 files changed, 44 insertions, 8 deletions

diff --git a/ediffract_new.tex b/ediffract_new.tex
index 8ace7bf..5e727c6 100644
--- a/ediffract_new.tex
+++ b/ediffract_new.tex
@@ -35,7 +35,7 @@
 
 \begin{figure}[h]
 \centering
-\includegraphics[width=\textwidth]{./pdf_figs/ed1_new} \caption{\label{ed1}Electron
+\includegraphics[width=0.6\textwidth]{./pdf_figs/ed1_new} \caption{\label{ed1}Electron
 Diffraction from atomic layers in a crystal.}
 \end{figure}
 \section*{Theory}
@@ -88,7 +88,7 @@ electron diffraction tube, make sure these connections are well-protected and
 cannot be touched by accident while taking measurements.
 \begin{figure}[h]
 \centering
-\includegraphics[width=6in]{./pdf_figs/ed2} \caption{\label{ed2}Electron Diffraction Apparatus.}
+\includegraphics[width=5in]{./pdf_figs/ed2} \caption{\label{ed2}Electron Diffraction Apparatus.}
 \end{figure}
 \subsection*{Setup}
 
@@ -126,9 +126,9 @@ Anode Current & $I_A$& 0.15 mA at 4000 V ( 0.20 mA max.)
 \item  Slowly increase $V_a$ until you observe two rings appear around the direct beam.
 Slowly change the voltage and determine the highest achievable accelerating
 voltage, and the lowest voltage when the rings are visible.
-\item  Measure the diffraction angle $\theta$ for both inner and outer rings for 5-10 voltages from that range,
-using the same thin receipt paper (see procedure below). Each lab partner should
-repeat these measurements (using an individual length of the thin paper).
+\item  Measure the diffraction angle $\theta$ for both inner and outer rings for 8-10 voltages from that range,
+using the same strip of a masking tape (see procedure below).
+\item Turn the voltage down, take a new masking tape and repeat the measurement procedure, using the same values of $V_a$ at least two more times.
 \item Calculate the average value of $\theta$ from the individual measurements for each
 voltage $V_a$. Calculate the uncertainties for each $\theta$.
 \end{enumerate}
@@ -150,10 +150,10 @@ where the distance between the target and the screen $L = 0.130$~m is controlled
 The ratio between the arc length $s$ and the
 radius of the curvature for the screen $R = 0.066$~m gives the angle $\phi$ in
 radians:  $\phi = s/2R$. To measure $\phi$ carefully place a piece of
-thin receipt paper on the tube so that it crosses the ring along the diameter.
+a masking tape on the tube so that it crosses the ring along the diameter.
 Mark the position of the ring for each accelerating voltage, and then
 remove the paper and measure the arc length $s$ corresponding to
-each ring. You can also make these markings on masking tape placed gently on the tube.
+each ring. 
 
 
 \begin{figure}
diff --git a/ediffract_prelab.tex b/ediffract_prelab.tex
new file mode 100644
index 0000000..77ecfa6
--- /dev/null
+++ b/ediffract_prelab.tex
@@ -0,0 +1,18 @@
+\documentclass[./manual.tex]{subfiles}
+\begin{document}
+
+\chapter*{Electron Diffraction - Pre-lab exercise}
+
+\textbf{Electron diffraction lab is relatively simple as the measurements go, but its data analysis part is more substantial than others.}
+
+\section*{1. Theoretical graph}
+
+    Prepare a theoretical plot of Eq.(1.5) from the manual, using known values of the parameters and making reasonable guess on the range of the expected angles $\theta$.
+
+\section*{2. Error propagation}
+How you can find the uncertainty of $\sin(\theta)$ from the instrumental uncertainty of $s$? Discuss if the trigonometrical functions can be simplified.
+
+
+
+\end{document}
+
diff --git a/interferometry_new.tex b/interferometry_new.tex
index 27d40b7..82b5863 100644
--- a/interferometry_new.tex
+++ b/interferometry_new.tex
@@ -1,7 +1,7 @@
 \documentclass[./manual.tex]{subfiles}
 \begin{document}
 
-\chapter{Optical Interferometry}
+\chapter*{Optical Interferometry}
 
 \noindent
  \textbf{Experiment objectives}: Assemble and align Michelson and Fabry-Perot
diff --git a/interferometry_prelab.tex b/interferometry_prelab.tex
new file mode 100644
index 0000000..b485fde
--- /dev/null
+++ b/interferometry_prelab.tex
@@ -0,0 +1,18 @@
+\documentclass[./manual.tex]{subfiles}
+\begin{document}
+
+\chapter*{Optical Interferometry - Pre-lab exercise}
+
+
+\section*{1. Theoretical graph}
+
+  Plot the theoretical dependence of the air refractive index on the pressure. Assume that in vacuum $n=1$, and at one atmosphere $p_0=76$~cm Hg it is $n_{STP}=1.000293$.
+  
+\section*{2. Error propagation}
+Derive the expressions for the uncertainty of the wavelength measurements, given by Eq.(4) and for the individual refractive index measurements, given by Eq.(5). 
+Discuss the strategy of reducing these uncertainty (assuming that you cannot upgrade the equipment).
+
+
+
+\end{document}
+