Changeset 6652

Timestamp:

02/21/05 19:24:32 (20 years ago)

Author:

gaug

Message:

*** empty log message ***

File:

• trunk/MagicSoft/TDAS-Extractor/MonteCarlo.tex (modified) (2 diffs)

trunk/MagicSoft/TDAS-Extractor/MonteCarlo.tex

@@ -22 +22 @@
 \item The low-gain pulse is not yet simulated with the correct pulse width, but instead the same pulse shape as the one of the 
 high-gain channel has been used.
+\item The low-gain pulse starts to saturate at already about 200 photo-electrons while in reality, 
+this limit lies at more than 500 photo-electrons for an inner pixel. This is due to the wider low-gain pulse in real conditions.
 \item The low-gain pulse is delayed by only 15 FADC slices in the Monte-Carlo simulations, while it arrives about 16.5 FADC slices 
 after the high-gain pulse in real conditions.
 \item No switching noise due to the low-gain switch has been simulated.
 \item The intrinsic transit time spread of the photo-multipliers has not been simulated.
+\item The pulses have been simulated in steps of 0.2\,ns before digitization. There is thus an artificial numerial time resolution 
+limit of $0.2\,\mathrm{ns}/\sqrt{12} \approx 0.06\,\mathrm{ns}$.
 \item The total dynamic range of the entire signal transmission chain was set to infinite, thus the detector has been simulated 
 to be completely linear.
@@ -268 +272 @@
 where $\widehat{T}_{rec}$ is the reconstructed arrival time and $T_{sim}$ the simulated one.
 \par
-
-
-
-\begin{figure}[htp]%%[t!]
+Generally, the time resolutions $\Delta T_{\mathrm{MC}}$ are about  a factor 1.5 better than those obtained 
+from the calibration (section~\ref{sec:cal:timeres}, figure~\ref{fig:time:dep}). This 
+ is understandable since the Monte-Carlo pulses are smaller and 
+further the intrinsic time spread of the photo-multiplier has not been simulated. Moreover, no time resolution offset was 
+simulated, thus the reconstructed time resolutions follow about a $1/\sqrt{N_{\mathrm{phe}}}$\,--\,behaviour over the whole low-gain range.
+The spline extractors level off in contradiction to what has been found with the calibration pulses.
+\par
+In figure~\ref{fig:mc:TimeRes_SlidW}, one can see nicely the effect of the addition of noise to the reconstructed time 
+resolution: While without noise all sliding window extractors with a window size of at least 4~FADC slices show the same time 
+resolution, with added noise, the resolution degrades with larger extraction window sizes. This can be understood by the fact that 
+an extractor covers the whole pulse if integrating at least 4~FADC slices and each additional slice can only be affected by the noise.
+
+\begin{figure}[htp]
 \centering
   \includegraphics[width=0.49\linewidth]{TimeAndChargePlots/TDAS_TimeRes_SlidW_NoNoise_HiGain.eps}