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Diffstat (limited to 'spectr.tex')
| -rw-r--r-- | spectr.tex | 19 |
1 files changed, 7 insertions, 12 deletions
@@ -300,7 +300,7 @@ where $m$ is the diffraction order, and $d$ is the distance between the lines in the collimator slit, swing the rotating telescope slowly through 90 degrees both on the left \& right sides of the forward direction. You should observe diffraction maxima for most - spectral wavelength, $\lambda$, in 1st, 2nd, and 3rd order. If these + spectral wavelength, $\lambda$, in 1st and 2nd order. If these lines seem to climb uphill or drop downhill the grating has to be adjusted in its baseclamp to bring them all to the same elevation. @@ -316,8 +316,7 @@ where $m$ is the diffraction order, and $d$ is the distance between the lines in \end{figure} Swing the rotating telescope slowly and determine which spectral lines from Balmer series you observe. You should be able to see three bright lines - Blue, Green and Red - in the first (m=1) and -second (m=2) diffraction orders on both left \& right sides. In the third order (m=3) only the Blue, -\& Green lines are visible, and you will not see the Red. +second (m=2) diffraction orders on both left \& right sides. %In the third order (m=3) only the Blue, \& Green lines are visible, and you will not see the Red. One more line of the Balmer series is in the visible range - Violet, but its intensity is much lower than for the other three line. However, you will be able to find it in the first order if you look @@ -337,7 +336,7 @@ spectrum resembling one shown in Fig.~\ref{fig:hydrogen_visible_spectrum}. % You might not see the Violet line due to its low % intensity. Red will not be seen in 3rd order. -After locating all the lines, measure the angles at which each line occurs. The spectrometer reading for each line should be measured at least \emph{twice} by \textit{different} lab partners to avoid systematic errors. \textbf{Don't forget}: for every line you need to measure the angles to the right and to the left! +After locating all the lines, measure the angles at which each line occurs. The spectrometer reading for each of the first order lines should be measured at least \emph{twice} by \textit{different} lab partners to avoid systematic errors. For the second order lines, you only need one measurement for your group. \textbf{Don't forget}: for every line you need to measure the angles to the right and to the left! You should be able to determine the angle with accuracy of $1$ minute, but you should know how to read angles with high precision in the spectrometer: first use the bottom scale to get the rough @@ -392,14 +391,10 @@ names are symbolic rather than descriptive! After that, carefully measure the left and right angles for as many spectral lines in the first and second orders -as possible. The spectrometer reading for each line should be measured at least \emph{twice} by -\textit{different} lab partners to avoid systematic errors. - -Determine the wavelengths of all measured Na spectral lines using Eq. \ref{nlambda}. Compare these -measured mean wavelengths to the accepted values given in Fig.~\ref{natrns} -and in the table~\ref{tab:sodium}. -Identify at least seven of the lines with a particular transition, e.g. $\lambda = 4494.3${\AA} -corresponds to $8d \rightarrow 3p$ transition. +as possible. The spectrometer reading for each line should be measured at least \emph{once} by +both lab partners to avoid systematic errors. + +Determine the wavelengths of all measured Na spectral lines using Eq. \ref{nlambda}. Compare these measured mean wavelengths to the accepted values given in Fig.~\ref{natrns} and in Tab.~\ref{tab:sodium}. Identify at least seven of the lines with a particular transition. The eight line in Tab.~\ref{tab:sodium} has a wavelength $\lambda = 4494.3${\AA}. It corresponds to the $8d \rightarrow 3p$ transition but isn't shown in Fig.~\ref{natrns}. \begin{table} |