\begin{figure}
	\centering
	\subfigure[Point A]
	{\includegraphics[width=6.6cm]{Images/tha-nocolors-100}\label{tha100}}
	\hspace{2mm}
	\subfigure[Point A (zoom)]
	{\includegraphics[width=6.6cm]{Images/tha-nocolors-60}\label{tha60}}
	\vspace{2mm}	
	\subfigure[Point P]
	{\includegraphics[width=6.6cm]{Images/thp-nocolors-100}\label{thp100}}
	\hspace{2mm}
	\subfigure[Point P (zoom)]
	{\includegraphics[width=6.6cm]{Images/thp-nocolors-60}\label{thp60}}
	\caption{Threshold scan results for \textit{zone A} and \textit{zone P}}
	\label{thscanplots}
\end{figure}

We ran an efficiency scan as a function of the VFAT2 threshold level for two different regions of the chamber (\textit{A} and \textit{P}). This is particularly useful to understand how much the threshold can be raised (for example, in order to work in noisy environments) while avoiding a significant loss of efficiency. To make the test simpler, we set the same threshold for all the channels at a time, even if their noise levels were quite different. However, a channel by channel adjustment is available, if needed, through VFAT2 \textit{TrimDAC} feature.\\

\figurename~\vref{thscanplots} shows the results of the test. The response of the chamber is satisfying: when working at high gain (referring to the sets of data taken at divider current $I\geq 850 \mu A$) we can arbitrarily raise the threshold to $th = 90 ds$ without virtually experiencing any efficiency loss. However, \textit{zone P} looks again less efficient than \textit{zone A}.\\

The plots in \figurename~\ref{thscanplots} also display an ostensible full efficiency ($\varepsilon \simeq 100 \% $) at $ th < 30 ds $. If we compare this result to those seen in \chaptername~\vref{ch-off-th}, it is clear that we are below the noise level: the efficiency seems high, but we are actually detecting more noise hits than particles.\\

\input{Parts/IntLandau}