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\newcommand{\COO}{CO$_2$}
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\textbf{FIR-Laser FIRL 100}
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\textbf{\COO{}-Startup-Procedure}

\begin{enumerate}
\item Before you start, check the following:
\begin{itemize}
\item \COO{} beam goes into power meter, not FIR cavity
\item FIR cavity pressure is low ($\approx$ 20 mTorr), i.e., pump is pumping the cavity
\item \COO{} gas is off, all valves closed, pump off
\item Chiller off
\item Set PZT control to hand controller, i.e., at the back of the power supply 
      connect the BNC labeled ``Piezo Drive EXT'' with the BNC labeled ``Piezo Drive INT'' using the short
      BNC cable.
\end{itemize}

\item Turn on \COO{} pump with pump and bleed valve closed. Allow warm up (few minutes). Pressure: 0-1 mbar.
\item Open pump valve and pump hose; check pressure: 0-1 mbar.
\item Open \COO{} cavity valve on laser head. Pump cavity down to 0-1 mbar.
\item Set gas regulater at \COO{} premix bottle to 1 atm/15 psi.
\item Open needle valve on laser head and adjust to read about 10 mbar.
\item Turn on chiller; allow $\approx$ 5 min for temperature stabilization (15$^{\circ}$C)
\item Turn on key-switch. HV-Off-light, Interlock-light, and Power-light must turn on.
\item After 10 sec. Ready-light comes on.
\item Turn HV on. Check current on current meter. Discharge is now on.
\item Set \COO{} pressure to about 29 mbar and check the power of the \COO{} beam.
      Power should be within approximately 10\% of calibration sheet value.
\end{enumerate}
\newpage

\textbf{Fill FIR cavity with methanol (single fill operation)}

\begin{enumerate}
\item On first fill of day, evacuate fill volume above CH$_4$. Pump on it for a while (about 60 mTorr).
\item Transfer CH$_4$ from bottle into fill volume.
\item Close off CH$_4$ supply, close valve to pump and open fill volume to cavity.
\item Close off fill volume and pump FIR cavity to required operating pressure. If unknow: pump to 100 mTorr
\end{enumerate}

\COO{} $\rightarrow$ FIR

\begin{enumerate}
\item Steer beam into FIR cavity
\item Observe FIR power on power meter.
\item Optimize PZT, cavity length, and FIR pressure. After a while, maybe take out some
      CH$_4$ to counteract \COO{} heating effect.
\item Also check FIR mode quality with liquid crystal paper. Should be TEM00.
\item Fill out FIR Logbook after before changing laser line!!!
\end{enumerate}
\newpage

\textbf{Shut-down procedure}

\begin{enumerate}
\item If using stabilizer: Switch PZT controller back to ``SEARCH'', and set PZT to 0 kV.
\item Turn off HV.
\item Turn off chiller.
\item Turn off Key-Switch.
\item Steer \COO{} beam into power meter.
\item Close \COO{} needle valve.
\item Close \COO{} gas cylinder.
\item Close \COO{} cavity valve after cavity pressure reduced to a few mbar.
\item Close \COO{} pump valve.
\item Turn off \COO{} pump.
\item Bleed \COO{} pump to atmosphere.
\item Turn off pyro-electric detector, \COO{} spectrum analyzer etc.
\item Start pumping the FIR cavity.
\end{enumerate}

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