added mercury spectrum

1 files changed, 25 insertions, 8 deletions

diff --git a/pe-effect.tex b/pe-effect.tex
index aaf1adc..073beb7 100644
--- a/pe-effect.tex
+++ b/pe-effect.tex
@@ -88,11 +88,29 @@ The Pasco photoelectric effect setup.}
 
 Set up the equipment as shown in Fig. \ref{pefig3}. First, place a lens/grating assembly in front of the Mercury
 lamp, and observe a dispersed spectrum on a sheet of paper, as shown in Fig.~\ref{fig:mercury_spectrum}. Identify spectral
-lines in both the first and the second diffraction orders on both sides. Keep in mind that the color
+lines in both the first and the second diffraction orders on both sides,
+use Fig.~\ref{fig:visible_mercury_spectrum} for the guidance. Keep in mind that the color
 ``assignment'' is fairly relative, and make sure you find all lines mentioned in the table in Fig.~\ref{fig:mercury_spectrum}.
 Often the first/second order lines on one side are brighter than on the other - check your apparatus and
 determine what orders you will be using in your experiment.
 
+\begin{figure}[h]
+\centering
+\includegraphics[width=\linewidth]{./pdf_figs/mercury_diffraction_spectrum}
+\caption{\label{fig:mercury_spectrum}
+The mercury lamp visible diffraction spectrum.}
+\end{figure}
+
+\begin{figure}[h]
+\centering
+\includegraphics[width=\linewidth]{{"./pdf_figs/Mercury visible spectrum"}.png}
+\caption{\label{fig:visible_mercury_spectrum}
+The mercury lamp visible spectrum. The spectrum is reconstructed according to NIST data
+provided at
+\url{https://physics.nist.gov/PhysRefData/Handbook/Tables/mercurytable2.htm}
+}
+\end{figure}
+
 After that, install the $h/e$ apparatus and focus the light from the mercury vapor light source onto the slot in
 the white reflective mask on the $h/e$ apparatus. Tilt the light shield of the apparatus out of the way to
 reveal the white photodiode mask inside the apparatus. Slide the Lens/Grating assembly forward and back on its
@@ -143,12 +161,6 @@ the $h/e$ apparatus.
 
 \end{enumerate}
 
-\begin{figure}[h]
-\centering
-\includegraphics[width=\linewidth]{./pdf_figs/mercury_diffraction_spectrum} \caption{\label{fig:mercury_spectrum}
-The mercury lamp visible diffraction spectrum.}
-\end{figure}
-
 \section*{Part B: The dependence of the stopping potential on the frequency of light}
 
 In this section you'll measure the stopping power for the five different emission lines of Mercury to demonstrate that the stopping power depends on, and is a measurement of, the wavelength (and frequency).  Your measurements will consist of the stopping power for each of the five Mercury lines, measured for both first and second orders.  This is a total of 10 data points.  You'll then analyze the data by fitting stopping power vs frequency to extract Planck's constant and the work function. That procedure is described in more detail in the next section. 
@@ -185,7 +197,12 @@ Read the theory of the detector operation in the Appendix, and explain why there
 \section*{The relationship between Energy, Wavelength and Frequency}
 
 \begin{enumerate}
-\item Use the table in Fig.~\ref{fig:mercury_spectrum} to find the exact frequencies and wavelengths of the spectral lines you used and plot the measured stopping potential values versus light frequency for measurements of the first and second order lines.
+	\item Use the table in Fig.~\ref{fig:mercury_spectrum} and
+		Fig.~\ref{fig:visible_mercury_spectrum} to find the exact
+		frequencies and wavelengths of the spectral lines you used
+		and plot the measured stopping potential values versus
+		light frequency for measurements of the first and second
+		order lines.
 
 \item Fit your data according to $eV_0 = h\nu-\phi$, extracting values for the slope and intercept. {\it Note, this fitting step takes the measurement uncertainties on the stopping power and propagates them to the slope and intercept.} It's important to do this step with Igor, Matlab, or some other tool which can compute a $\chi^2$, minimize it with respect to the fit parameters, and then report the parameter uncertainties.  From the slope, determine  $h$ using $e=1.6\cdot10^{-19}$~C. Find the average value and uncertainty on the average. Does your value agree with the accepted value of  $h=6.62606957(29) \times 10^{-34}$J$\cdot$s within uncertainty?