Changeset 6648 for trunk/MagicSoft
- Timestamp:
- 02/21/05 15:59:39 (20 years ago)
- Location:
- trunk/MagicSoft/TDAS-Extractor
- Files:
-
- 4 edited
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- Unmodified
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trunk/MagicSoft/TDAS-Extractor/Introduction.tex
r6562 r6648 24 24 \end{center} 25 25 \caption[Current MAGIC read-out scheme.]{Current MAGIC read-out scheme: the analog PMT signals are 26 transferred via an analog optical link to the counting house where after the trigger decisionthe signals27 are digitized by usinga 300 MHz FADCs system and written to the hard disk of a DAQ PC.}26 transferred via an analog optical link to the counting house -- where after the trigger decision -- the signals 27 are digitized by a 300 MHz FADCs system and written to the hard disk of a DAQ PC.} 28 28 \label{fig:MAGIC_read-out_scheme} 29 29 \end{figure} … … 34 34 35 35 36 In order to sample this pulse shape with the used 300 MSamples/s FADC system, the pulse is shaped to a 37 FWHM greater than 6\,ns 38 (the original pulse is folded with a stretching function of 6ns). Because the MAGIC FADCs have a 36 In order to sample this pulse shape with the 300 MSamples/s FADC system, the original pulse is folded with a stretching function of 6ns leading to a FWHM greater than 6\,ns. Because the MAGIC FADCs have a 39 37 resolution of 8 bit only, the signals are split into two branches with gains differing by a factor 10. 40 38 One branch is delayed by 55\,ns and then both branches are multiplexed and consecutively read-out by one FADC. 41 Figure~\ref{fig:pulpo_shape_high} shows a typical average of identical inputsignals. A more detailed overview about the MAGIC read-out and DAQ system is given in \cite{Magic-DAQ}.39 Figure~\ref{fig:pulpo_shape_high} shows a typical average of identical signals. A more detailed overview about the MAGIC read-out and DAQ system is given in \cite{Magic-DAQ}. 42 40 % The maximum sustained trigger rate could be 1 kHz. The FADCs feature a FIFO memory which allows a significantly higher short-time rate. 43 41 % Obviously by doing this, more LONS is integrated and thus the performance of the telescope on the analysis level is degraded. -
trunk/MagicSoft/TDAS-Extractor/MonteCarlo.tex
r6646 r6648 255 255 \clearpage 256 256 257 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%5 257 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 258 259 \subsection{Arrival Times \label{sec:mc:times}} 260 261 Like in the case of the charge resolution, we calculated the RMS of the distribution of the deviation of the 262 reconstructed arrival time with respect to the simulated time: 263 264 \begin{equation} 265 \Delta T_{\mathrm{MC}} \approx RMS(\widehat{T}_{rec} - T_{sim}) 266 \end{equation} 267 268 where $\widehat{T}_{rec}$ is the reconstructed arrival time and $T_{sim}$ the simulated one. 269 \par 270 271 272 273 \begin{figure}[htp]%%[t!] 274 \centering 275 \includegraphics[width=0.49\linewidth]{TimeAndChargePlots/TDAS_TimeRes_SlidW_NoNoise_HiGain.eps} 276 \vspace{\floatsep} 277 \includegraphics[width=0.49\linewidth]{TimeAndChargePlots/TDAS_TimeRes_SlidW_WithNoise_HiGain.eps} 278 \vspace{\floatsep} 279 \includegraphics[width=0.49\linewidth]{TimeAndChargePlots/TDAS_TimeRes_SlidW_NoNoise_LoGain.eps} 280 \vspace{\floatsep} 281 \includegraphics[width=0.49\linewidth]{TimeAndChargePlots/TDAS_TimeRes_SlidW_WithNoise_LoGain.eps} 282 \caption[Time Resolution Sliding Windows]{The measured time resolution (RMS of extracted time minus simulated time) 283 versus number of photoelectrons, 284 for sliding window extractors in different window sizes. The top plots show the high-gain and the bottom ones 285 low-gain regions. Left: without noise, right: with simulated noise.} 286 \label{fig:mc:TimeRes_SlidW} 287 \end{figure} 288 289 \begin{figure}[htp] 290 \centering 291 \includegraphics[width=0.49\linewidth]{TimeAndChargePlots/TDAS_TimeRes_DFSpline_NoNoise_HiGain.eps} 292 \vspace{\floatsep} 293 \includegraphics[width=0.49\linewidth]{TimeAndChargePlots/TDAS_TimeRes_DFSpline_WithNoise_HiGain.eps} 294 \vspace{\floatsep} 295 \includegraphics[width=0.49\linewidth]{TimeAndChargePlots/TDAS_TimeRes_DFSpline_NoNoise_LoGain.eps} 296 \vspace{\floatsep} 297 \includegraphics[width=0.49\linewidth]{TimeAndChargePlots/TDAS_TimeRes_DFSpline_WithNoise_LoGain.eps} 298 \caption[Time Resolution Spline and Digital Filter]{The measured time resolution (RMS of extracted time minus simulated time) 299 versus number of photoelectrons, 300 for spline and digital filter window extractors in different window sizes. The top plots show the high-gain and the bottom ones 301 low-gain regions. Left: without noise, right: with simulated noise.} 302 \label{fig:mc:TimeRes_DFSpline} 303 \end{figure} 304 305 306 %%% Local Variables: 307 %%% mode: latex 308 %%% TeX-master: "MAGIC_signal_reco" 309 %%% End: 310 311 312 313 314 315 316 317 318 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 319 320 \clearpage 258 321 259 322 \subsection{Charge Signals with and without Simulated Noise \label{fig:mc:sec:mc:chargenoise}} 323 260 324 261 325 \begin{figure}[htp] … … 282 346 \label{fig:mc:Bias_LoGain} 283 347 \end{figure} 284 285 \clearpage286 287 \subsection{Arrival Times \label{sec:mc:times}}288 289 \begin{figure}[htp]%%[t!]290 \centering291 \includegraphics[width=0.49\linewidth]{TimeAndChargePlots/TDAS_TimeRes_SlidW_NoNoise_HiGain.eps}292 \vspace{\floatsep}293 \includegraphics[width=0.49\linewidth]{TimeAndChargePlots/TDAS_TimeRes_SlidW_WithNoise_HiGain.eps}294 \vspace{\floatsep}295 \includegraphics[width=0.49\linewidth]{TimeAndChargePlots/TDAS_TimeRes_SlidW_NoNoise_LoGain.eps}296 \vspace{\floatsep}297 \includegraphics[width=0.49\linewidth]{TimeAndChargePlots/TDAS_TimeRes_SlidW_WithNoise_LoGain.eps}298 \caption[Time Resolution Sliding Windows]{The measured time resolution (RMS of extracted time minus simulated time)299 versus number of photoelectrons,300 for sliding window extractors in different window sizes. The top plots show the high-gain and the bottom ones301 low-gain regions. Left: without noise, right: with simulated noise.}302 \label{fig:mc:TimeRes_SlidW}303 \end{figure}304 305 \begin{figure}[htp]306 \centering307 \includegraphics[width=0.49\linewidth]{TimeAndChargePlots/TDAS_TimeRes_DFSpline_NoNoise_HiGain.eps}308 \vspace{\floatsep}309 \includegraphics[width=0.49\linewidth]{TimeAndChargePlots/TDAS_TimeRes_DFSpline_WithNoise_HiGain.eps}310 \vspace{\floatsep}311 \includegraphics[width=0.49\linewidth]{TimeAndChargePlots/TDAS_TimeRes_DFSpline_NoNoise_LoGain.eps}312 \vspace{\floatsep}313 \includegraphics[width=0.49\linewidth]{TimeAndChargePlots/TDAS_TimeRes_DFSpline_WithNoise_LoGain.eps}314 \caption[Time Resolution Spline and Digital Filter]{The measured time resolution (RMS of extracted time minus simulated time)315 versus number of photoelectrons,316 for spline and digital filter window extractors in different window sizes. The top plots show the high-gain and the bottom ones317 low-gain regions. Left: without noise, right: with simulated noise.}318 \label{fig:mc:TimeRes_DFSpline}319 \end{figure}320 321 322 %%% Local Variables:323 %%% mode: latex324 %%% TeX-master: "MAGIC_signal_reco"325 %%% End: -
trunk/MagicSoft/TDAS-Extractor/Reconstruction.tex
r6552 r6648 3 3 The FADC clock is not synchronized with the trigger. Therefore, the relative position of the recorded 4 4 signal samples varies from event to event with respect to the position of the signal shape. 5 The time between the trigger decision and the first read-out sample is uniformly distributed in the range5 The time $\Delta t$ between the trigger decision and the first read-out sample is uniformly distributed in the range 6 6 $t_{\text{rel}} \in [0,T_{\mathrm{FADC}}[$, where $T_{\mathrm{FADC}}=3.33$\,ns is the digitization period of the MAGIC 300\,MHz FADCs. 7 Itcan be determined using the reconstructed arrival time7 $\Delta t$ can be determined using the reconstructed arrival time 8 8 $t_{\mathrm{arrival}}$.%directly by a time to digital converter (TDC) or 9 9 … … 30 30 31 31 The asynchronous sampling of the pulse shape allows to determine an average pulse shape from the recorded 32 signal samples: The recorded signal samples can be shifted in time such that the shifted arrival times32 signal samples: The recorded signal samples are shifted in time such that the shifted arrival times 33 33 of all events are equal. In addition, the signal samples are normalized event by event using the 34 34 reconstructed charge of the pulse. The accuracy of the signal shape reconstruction depends on the accuracy 35 of the arrival time and charge reconstruction. The statistical error of the reconstructed pulse shape is well below $10^{-2}$ while the systematical error is by definition unknown at first hand.35 of the arrival time and charge reconstruction. The relative statistical error of the reconstructed pulse shape is well below $10^{-2}$ while the systematical error is by definition unknown at first hand. 36 36 37 37 … … 81 81 reconstructed pulse shape for cosmics events, both have a FWHM of about 6.3 ns. As air showers due to hadronic cosmic rays trigger the telescope 82 82 much more frequently than gamma showers the reconstructed pulse shape of the cosmics events corresponds mainly to hadron induced showers. 83 The pulse shape due to electromagnetic air showers might be slightly different . The pulse shape for green calibration LED pulses is wider83 The pulse shape due to electromagnetic air showers might be slightly different as indicated by MC simulations \cite{MC_timing_Indians}. The pulse shape for green calibration LED pulses is wider 84 84 and has a pronounced tail. 85 85 -
trunk/MagicSoft/TDAS-Extractor/bibfile.bib
r6543 r6648 1 @ARTICLE{MC_timing_Indians, 2 author = {{Chitnis}, V.~R. and {Bhat}, P.~N.}, 3 title = "{Possible discrimination between gamma rays and hadrons using {\v C}erenkov photon timing measurements}", 4 journal = {Astroparticle Physics}, 5 year = 2001, 6 month = mar, 7 volume = 15, 8 pages = {29-47}, 9 adsurl = {http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=2001APh....15...29C&db_key=AST}, 10 adsnote = {Provided by the NASA Astrophysics Data System} 11 } 12 13 1 14 @Article{low_energy, 2 15 author = "Baixeras, C. and others",
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