quotation typo fixed

5 files changed, 6 insertions, 6 deletions

diff --git a/ediffract.tex b/ediffract.tex
index 5ee2ec8..96cbd58 100644
--- a/ediffract.tex
+++ b/ediffract.tex
@@ -40,7 +40,7 @@ Diffraction from atomic layers in a crystal.}
 \end{figure}
 \section*{Theory}
     Consider planes of atoms in a {\bf crystal} as shown in Fig, \ref{ed1}
-separated by distance $d$. Electron "waves" reflect from each of these planes.
+separated by distance $d$. Electron ``waves'' reflect from each of these planes.
 Since the electron is wave-like, the combination of the reflections from each
 interface will lead to an interference pattern. This is completely analogous to
 light interference, arising, for example, from different path lengths in the
diff --git a/interferometry.tex b/interferometry.tex
index d3ed02b..62487ae 100644
--- a/interferometry.tex
+++ b/interferometry.tex
@@ -163,7 +163,7 @@ Each lab partner should make at least two independent measurements, starting fro
 \item Avoid touching the face of the front-surface mirrors, the beamsplitter, and any other optical elements!
 \item The person turning the micrometer should also do the counting of fringes. It can be easier to count them in bunches of 5 or 10 (\textit{i.e.} 100 fringes = 10 bunches of 10 fringes).
 \item Use a reference point or line and count fringes as they pass.
-\item  Before the initial position $X_1$ is read make sure that the micrometer has engaged the drive screw (There can be a problem with "backlash"). Just turn it randomly before counting.
+\item  Before the initial position $X_1$ is read make sure that the micrometer has engaged the drive screw (There can be a problem with ``backlash''). Just turn it randomly before counting.
 \item  Avoid hitting the table which can cause a sudden jump in the number of fringes.
 \end{enumerate}
 
diff --git a/single-photon-interference.tex b/single-photon-interference.tex
index 056d1fc..31c3310 100644
--- a/single-photon-interference.tex
+++ b/single-photon-interference.tex
@@ -238,7 +238,7 @@ Now you need to change the apparatus to use the light bulb. Open the cover and s
 
 Now close and lock the cover - you are ready to start counting photons. But first a WARNING:  a photomultiplier tube is so sensitive a device that it should not be exposed even to moderate levels of light when turned off, and must not be exposed to anything but the dimmest of lights when turned on.  In this context, ordinary room light is intolerably bright even to a PMT turned off, and light as dim as moonlight is much too bright for a PMT turned on.
 
-\textbf{Direct observation of photomultiplier pulses} You will use a digital oscilloscope for first examination of the PMT output pulses, and a digital counter for counting the photon events. Set the oscilloscope level to about 50~mV/division vertically, and 250 - 500~ns/division horizontally, and set it to trigger on positive-going pulses or edges of perhaps $>20$~mV height. Now find the PHOTOMULTIPLIER OUTPUT of the detector box, and connect it via a BNC cable to the vertical input of the oscilloscope. Keeping the shutter closed, set the HIGH-VOLTAGE 10-turn dial to 0.00, and turn on the HIGH-VOLTAGE toggle switch. Start to increase the voltage while watching the scope display. \emph{If you see some sinusoidal modulation of a few mV amplitude, and of about 200 kHz frequency, in the baseline of the PMT signal, this is normal. If you see a continuing high rate ($>10$~kHz) of pulses from the PMT, this is not normal, and you should turn down, or off, the bias level and start fresh -- you may have a malfunction, or a light leak.} Somewhere around a setting of 4 or 5 turns of the dial, you should get occasional positive-going pulses on the scope, occurring at a modest rate of $1-10$ per second. If you see this low rate of pulses, you have discovered the ``dark rate'' of the PMT, its output pulse rate even in the total absence of light.  You also now have the PMT ready to look at photons from your two-slit apparatus, so finally you may open the shutter.  The oscilloscope should now show a much greater rate of pulses, perhaps of order $10^3$ per second, and that rate should vary systematically with the setting of the bulb intensity. \emph{You may find a small device called Cricket in your table. It allows you to "hear" the individual photon arrivals - ask your instructor to show you how it works.}
+\textbf{Direct observation of photomultiplier pulses} You will use a digital oscilloscope for first examination of the PMT output pulses, and a digital counter for counting the photon events. Set the oscilloscope level to about 50~mV/division vertically, and 250 - 500~ns/division horizontally, and set it to trigger on positive-going pulses or edges of perhaps $>20$~mV height. Now find the PHOTOMULTIPLIER OUTPUT of the detector box, and connect it via a BNC cable to the vertical input of the oscilloscope. Keeping the shutter closed, set the HIGH-VOLTAGE 10-turn dial to 0.00, and turn on the HIGH-VOLTAGE toggle switch. Start to increase the voltage while watching the scope display. \emph{If you see some sinusoidal modulation of a few mV amplitude, and of about 200 kHz frequency, in the baseline of the PMT signal, this is normal. If you see a continuing high rate ($>10$~kHz) of pulses from the PMT, this is not normal, and you should turn down, or off, the bias level and start fresh -- you may have a malfunction, or a light leak.} Somewhere around a setting of 4 or 5 turns of the dial, you should get occasional positive-going pulses on the scope, occurring at a modest rate of $1-10$ per second. If you see this low rate of pulses, you have discovered the ``dark rate'' of the PMT, its output pulse rate even in the total absence of light.  You also now have the PMT ready to look at photons from your two-slit apparatus, so finally you may open the shutter.  The oscilloscope should now show a much greater rate of pulses, perhaps of order $10^3$ per second, and that rate should vary systematically with the setting of the bulb intensity. \emph{You may find a small device called Cricket in your table. It allows you to ``hear'' the individual photon arrivals - ask your instructor to show you how it works.}
 
 To count the pulses using a counter you will use another PMT output -- the OUTPUT TTL -- that generates a single pulse, of fixed height and duration, each time the analog pulse exceeds an adjustable threshold. To adjust the TTL settings display  the OUTPUT TTL on the second oscilloscope channel and set it for 2 V/div vertically.  By simultaneously watching both analog and TTL-level pulses on the display, you should be able to find a discriminator setting, low on the dial, for which the scope shows one TTL pulse for each of, and for only, those analog pulses which reach (say) a $+50$~-mV level. If your analog pulses are mostly not this high, you can raise the PMT bias by half a turn (50 Volts) to gain more electron multiplication. If your TTL pulses come much more frequently than the analog pulses, set the discriminator dial lower on its scale.
 
@@ -252,7 +252,7 @@ convenient count rate ($10^3 - 10^4$ events/second) at the central maximum.
 %the range 300 to 650 V. When you plot the two count rates on a semi-logarithmic graph, you should see the
 %``light rate'' reach a plateau, with the interpretation that you have reached a PMT bias which allow each
 %photoelectron to trigger the whole chain of electronics all the way to the TTL counter; you should also see the
-%(much lower) 'dark rate' also rising with PMT bias.  Based on your graph choose the PMT bias setting at which
+%(much lower) `dark rate' also rising with PMT bias.  Based on your graph choose the PMT bias setting at which
 %you are counting substantially all true photon events, but minimizing the number of ``dark events''.
 
 \textbf{Single-photon detection of the interference pattern}. Most likely the experimental results in the
diff --git a/spectr.tex b/spectr.tex
index 6a32ad0..8682030 100644
--- a/spectr.tex
+++ b/spectr.tex
@@ -40,7 +40,7 @@ is a fundamental physical constant called the {\bf Rydberg constant} (here $m_e$
 mass).  Numerically, ${R_y} = 1.0974 \times  10^5 cm^{-1}$ and $hc{R_y} = 13.605 eV$.
 
 Because the allowed energies of an electron in a hydrogen atom, the electron can change its state
-only by making a transition ("jump") from an one state of energy  $E_1$ to another state of lower
+only by making a transition (``jump'') from an one state of energy  $E_1$ to another state of lower
 energy $E_2$ by emitting a photon of energy $h\nu  = E_1 - E_2$ that carries away the excess energy.
 Thus, by exciting atoms into high-energy states using a discharge and then measuring the  frequencies
 of  emission  one can figure out the energy separation between various energy levels. Since it is
diff --git a/supcon.tex b/supcon.tex
index b8d2306..22d5da3 100644
--- a/supcon.tex
+++ b/supcon.tex
@@ -25,7 +25,7 @@ between a metal and insulator: while it has a full band (the valence band),
 the next band (the conduction band) is close enough in energy and so that the
 electrons can easily reach it. Superconductors are in a class by themselves.
 They can be metals or insulators at room temperature. Below a certain
-temperature, called the critical temperature, the electrons "pair" together (in
+temperature, called the critical temperature, the electrons ``pair'' together (in
 Cooper pairs) and travel through the solid without resistance. Current in a
 superconductor below the critical temperature will travel indefinitely without
 dissipation.