From c15636f660cf02a2e6e32363a8cf0bceaca0fdfe Mon Sep 17 00:00:00 2001 From: Nam Tran Date: Tue, 9 May 2017 11:59:57 -0500 Subject: [PATCH] update r15a_gamma report according to Jim's comments --- r15a_1809_rate/r15a_gamma.tex | 52 +++++--- stm_study_201611/stm_study.bib | 13 ++ stm_study_201611/stm_study.tex | 210 +++++++++++++++++++++++++++------ 3 files changed, 217 insertions(+), 58 deletions(-) diff --git a/r15a_1809_rate/r15a_gamma.tex b/r15a_1809_rate/r15a_gamma.tex index 3a7861b..f93b5bf 100644 --- a/r15a_1809_rate/r15a_gamma.tex +++ b/r15a_1809_rate/r15a_gamma.tex @@ -119,7 +119,9 @@ pulses from HPGe and \ce{LaBr3} detectors are shown in \includegraphics[width=1.0\textwidth]{figs/typical_pulses} \caption{Typical output pulses of HPGe and \ce{LaBr3} detectors: energy output HPGe high gain (top left), energy output HPGe low gain (top - right), timing output HPGe (bottom left), and \ce{LaBr3} (bottom right).} + right), timing output HPGe (bottom left), and \ce{LaBr3} (bottom right). + Each clock tick corresponds to \SI{10}{\ns} and \SI{2}{\ns} for top and + bottom plots, respectively.} \label{fig:typical_pulses} \end{figure} \end{center} @@ -127,8 +129,9 @@ pulses from HPGe and \ce{LaBr3} detectors are shown in The timing pulses from the HPGe detector were not used in this analysis because they are too long and noisy (see bottom left \cref{fig:typical_pulses}). Energy of the HPGe detector is taken as amplitude of spectroscopy amplifier -outputs, its timing is determined by the clock tick where the trace passing -\SI{30}{\percent} of the amplitude. +outputs, its timing is determined by the clock tick where the trace passes +\SI{30}{\percent} of the amplitude. The timing resolution is \SI{235}{\ns} +using this method. \ce{LaBr3} pulses were passed through a moving average window filter (60 samples wide), then integrated to obtain energy resolution. @@ -141,14 +144,16 @@ position. There was a separate run for background radiation. \cref{fig:uncalibrated_labr3_spectra} shows \ce{LaBr3} spectra with calibration sources \ce{^{88}Y}, \ce{^{60}Co}, and background -radiation. It can be seen that the self activation from \ce{Ac} dominates the -spectra. The \SI{1173}{\kilo\eV} peak barely shows up in \ce{^{60}Co} -spectrum, while the \SI{1332}{\keV} peak is buried under the -\SI{1436}{\kilo\eV} peak from \ce{^{138}La}. The \SI{1836}{\kilo\eV} -peak of \ce{^{88}Y} and the annihilation peak \SI{511}{\kilo\eV} can be -distinguished, but the \SI{898}{\kilo\eV} has been distorted by the electrons -and \SI{789}{\kilo\eV} gammas from the beta decay of \ce{^{138}La}. The energy -resolution (FWHM) at the \SI{1836}{\kilo\eV} peak was \SI{5.9}{\percent}. +radiation. It can be seen that below \SI{1.5}{\MeV} region the self activation +from \ce{^{138}La} shows up clearly, and above that products from the chain +decay of \ce{^{227}Ac} dominate the spectrum. The \SI{1173}{\kilo\eV} peak +barely shows up in \ce{^{60}Co} spectrum, while the \SI{1332}{\keV} peak is +buried under the \SI{1436}{\kilo\eV} peak from \ce{^{138}La}. The +\SI{1836}{\kilo\eV} peak of \ce{^{88}Y} and the annihilation peak +\SI{511}{\kilo\eV} can be distinguished, but the \SI{898}{\kilo\eV} has been +distorted by the electrons and \SI{789}{\kilo\eV} gammas from the beta decay of +\ce{^{138}La}. The energy resolution (FWHM) at the \SI{1836}{\kilo\eV} peak was +\SI{5.9}{\percent}. \begin{center} \begin{figure}[htbp] @@ -162,6 +167,7 @@ resolution (FWHM) at the \SI{1836}{\kilo\eV} peak was \SI{5.9}{\percent}. \end{center} The HPGe spectra are much cleaner as shown in Figure~\ref{fig:hpge_ecal}. +Energy resolutions are better than \SI{3.2}{\keV} for all calibrated peaks. \begin{center} \begin{figure}[htbp] \centering @@ -215,12 +221,20 @@ $2p-1s$ & 346.8 & \num{7.26e-4} &\num{4.73e-5} \\ \label{sub:labr3_spectra} The \ce{LaBr3} energy spectra for the Al dataset are presented in \cref{fig:labr3_all_al_runs}. The muonic $2p-1s$ peak shows up clearly in -the prompt spectrum as expected. The \SI{1809}{\kilo\eV} peak can be -recognized, it has better -signal-to-background ratio in the prompt spectrum than in the delay spectrum -(0.88 to 0.33). The background under the \SI{1809}{\kilo\eV} is dominated by -the $\alpha$ decay of progenies from \ce{^{227}Ac}. I think that this -\ce{LaBr3} in the current set up is not suitable to use as a STM detector. +the prompt spectrum as expected, the signal-to-background ratio is +\num{3.13(2)}. The \SI{1809}{\kilo\eV} peak can be +recognized, it has better signal-to-background ratio in the prompt spectrum +than in the delay spectrum (0.88 to 0.33). The background under the +\SI{1809}{\kilo\eV} is dominated by +the $\alpha$ decay of progenies from \ce{^{227}Ac}. + +It is clear that this +\ce{LaBr3} detector in the current set up is not good enough to measure the +\SI{1809}{\keV} line. The situation of the $2p-1s$ line is a little better, but +more studies is needed to understand the background and possible interferences +around the peak. On another note, there have been steady progress in +manufacturing \ce{LaBr3} detectors, and better performance has been observed. + \begin{center} \begin{figure}[htbp] \centering @@ -288,7 +302,7 @@ Therefore the emission rate per nuclear capture is: R_{1808.7} = \frac{N_{1808.7}}{A_{1808.7} \times N_{\mu} \times 0.609} = 0.51 \pm 0.05, \end{equation} , where the factor 0.609 comes from the fact that only \SI{60.9}{\percent} of -stopped muons are captured. This result is consistent with the rate reported -by Measday et al. +stopped muons are captured. This result is consistent with the rate +\num{0.51(5)} reported by Measday et al. \end{document} diff --git a/stm_study_201611/stm_study.bib b/stm_study_201611/stm_study.bib index 74e53a8..74b7bcf 100644 --- a/stm_study_201611/stm_study.bib +++ b/stm_study_201611/stm_study.bib @@ -457,6 +457,19 @@ Url = {http://www.sciencedirect.com/science/article/pii/0031916364904792} } +@TechReport{Bartoszek2014, + Title = {{Mu2e Technical Design Report}}, + Author = {Bartoszek, L. and others}, + Year = {2014}, + + Archiveprefix = {arXiv}, + Collaboration = {Mu2e}, + Eprint = {1501.05241}, + Primaryclass = {physics.ins-det}, + Reportnumber = {FERMILAB-TM-2594, FERMILAB-DESIGN-2014-01}, + Slaccitation = {%%CITATION = ARXIV:1501.05241;%%} +} + @Article{BauerBortels.1990, Title = {Response of Si detectors to electrons, deuterons and alpha particles}, Author = {Bauer, P and Bortels, G}, diff --git a/stm_study_201611/stm_study.tex b/stm_study_201611/stm_study.tex index 7f0004f..1f5589b 100644 --- a/stm_study_201611/stm_study.tex +++ b/stm_study_201611/stm_study.tex @@ -12,22 +12,40 @@ detect-family=true, separate-uncertainty=true]{siunitx} % \usepackage{listings} -\usepackage{xcolor} +\usepackage[dvipsnames]{xcolor} \usepackage{upquote} \usepackage{minted} \usemintedstyle{perldoc} \usepackage[framemethod=tikz]{mdframed} +\usepackage{adjustbox} -\definecolor{greybg}{rgb}{0.25,0.25,0.25} -\definecolor{yellowbg}{rgb}{0.91, 0.84, 0.42} -\definecolor{bananamania}{rgb}{0.98, 0.91, 0.71} +% \definecolor{greybg}{rgb}{0.25,0.25,0.25} +% \definecolor{yellowbg}{rgb}{0.91, 0.84, 0.42} +% \definecolor{bananamania}{rgb}{0.98, 0.91, 0.71} -\mdfsetup{% - middlelinecolor=red, - middlelinewidth=1pt, +\mdfdefinestyle{warning}{% + linecolor=red!70, + frametitle={Warning}, + frametitlerule=true, + frametitlebackgroundcolor=orange!40, + backgroundcolor=orange!30, + innertopmargin=\topskip, + roundcorner=8pt, + linewidth=1pt, +} +% \mdtheorem[style=theoremstyle]{warning}{Warning} + +\mdfdefinestyle{listing}{% + linecolor=Aquamarine!50, + linewidth=1pt, backgroundcolor=yellow!40, - roundcorner=8pt} + roundcorner=8pt, + % frametitlerule=true, + % frametitlebackgroundcolor=yellow!50, + innertopmargin=\topskip, +} +% \mdtheorem[style=listing]{listing}{Listing} % \DeclareSIUnit\eVperc{\eV\per\clight} % \DeclareSIUnit\clight{\text{\ensuremath{c}}} @@ -86,16 +104,16 @@ The study was done using Mu2e Offline version v6\textunderscore TS5 (see \cref{fig:stm_geo_all}), taking \texttt{cd3-beam-g4s2-mubeam.0728a} dataset as input. The dataset contains 5098 files, each corresponds to \num{1e6} proton-on-target (POT). The dataset were reused 16 times with -different random seeds, where \SI{97}{\percent} of runs succeeded, equivalent -to \num{8e11} POTs. +different random seeds, where \SI{97.6}{\percent} of runs succeeded, equivalent +to \num{7.96e10} POTs. \begin{figure}[htbp] \centering \includegraphics[width=1.0\textwidth]{figs/stm_geo_all} - \caption{Simulation geometry showing the DS region on the left, sweeper magnet, - FOV collimator, spot-size collimator, and the STM detectors on the right. - Particles saved in the input files are shoot from the TS5 (orange circle), - and transported to the STM region.} + \caption{Simulation geometry showing the Detector Solenoid region on the + left, sweeper magnet, Field-Of-View collimator, Spot-Size collimator, and + the STM detectors on the right. Particles saved in the input files are + shoot from the TS5 (orange circle), and transported to the STM region.} \label{fig:stm_geo_all} \end{figure} @@ -112,6 +130,8 @@ the output file. \centering \caption{List of virtual detectors read out in this study} \label{tab:vds_list} +\begin{adjustbox}{max width=\textwidth} + \begin{tabular}{@{}ccll@{}} \toprule &VDID & Location & Abbreviation \\ @@ -126,6 +146,7 @@ the output file. 8 & 100 & Downstream of the FOV collimator & STM\textunderscore FieldOfViewCollDnStr \\ \bottomrule \end{tabular} +\end{adjustbox} \end{table} \section{Simulation and analysis code} @@ -135,13 +156,13 @@ The simulation and analysis code are located at: \url{/mu2e/app/users/namtran/STM_study_201611}. % \lstinputlisting[language=bash,frame=single]{listings/code_dir_tree.sh} -\begin{mdframed} +\begin{mdframed}[style=listing] \inputminted[fontsize=\footnotesize]{bash}{listings/code_dir_tree.sh} \end{mdframed} \texttt{step00} contains configuration files for this simulation and a script to -submit all 5098 jobs (correspond to number of input files) to the FermiGrid. -It took about 14 hours to complete a job in average. +submit all 5098 jobs to the FermiGrid. It took about 14 hours to complete one +job in average. The \texttt{analysis} folder contains a script (\texttt{run\textunderscore statistics.sh}) which checks if a job has finished @@ -151,25 +172,30 @@ make plots. \section{Results} \label{sec:results} -\subsection{STM detector spectra} -\label{sub:stm_detector_spectra} +\begin{mdframed}[style=warning] +Muonic X-rays and probabilities in the simulation are not correct (see +\cref{sec:muonic_x_rays_in_geant4}). +\end{mdframed} -Energy spectrum of particles hitting STM detectors are presented in -\cref{fig:stm_det_ke}. There were not many hits, and only the annihilation -peak stands out. Most of the particles are photons as shown in +\subsection{STM detector energy spectra} +\label{sub:stm_detector_spectra} +Energy spectrum of particles hitting STM detectors in the range +\SIrange{0.1}{3.1}{\MeV} are presented in \cref{fig:stm_det_ke}. There were not many +hits, and only the annihilation peak stands out. Most of the particles are +photons as shown in \cref{fig:stm_det_ptype}. \begin{figure}[htbp] \centering - \includegraphics[width=0.7\textwidth]{figs/ke_det1UpStr} - \includegraphics[width=0.7\textwidth]{figs/ke_det2UpStr} + \includegraphics[width=0.85\textwidth]{figs/ke_det1UpStr} + \includegraphics[width=0.85\textwidth]{figs/ke_det2UpStr} \caption{Kinetic energy of particles hitting STM detectors 1 (top), and 2 (bottom).} \label{fig:stm_det_ke} \end{figure} \begin{figure}[htbp] \centering - \includegraphics[width=0.7\textwidth]{figs/ke_pdg_det1UpStr} - \includegraphics[width=0.7\textwidth]{figs/ke_pdg_det2UpStr} + \includegraphics[width=\textwidth]{figs/ke_pdg_det1UpStr} + \includegraphics[width=\textwidth]{figs/ke_pdg_det2UpStr} \caption{Kinetic energy and type of particles hitting STM detectors 1 (top), and 2 (bottom).} \label{fig:stm_det_ptype} @@ -179,32 +205,138 @@ peak stands out. Most of the particles are photons as shown in \label{sub:stm_detector_hit_rate_estimation} The average number of hits on a STM detector per POT is: \begin{equation} - \frac{888 + 888}{2 \times 8 \times 10^{11}} = 8.7 \times 10^{-9}. + \frac{672 + 714}{2 \times 7.96 \times 10^{10}} = 8.7 \times 10^{-9}. + \label{eqn:stm_hit_count} \end{equation} -There are 3.1 POTs per proton bunch, so the number of hits per bunch is: +There would be \num{3.1e7} POTs per proton bunch, so the number of hits each +bunch is: \begin{equation} - 8.7 \times 10^{-9} \times 3.1 \times 10^7 = 0.27 + 8.7 \times 10^{-9} \times 3.1 \times 10^7 = 0.27. \end{equation} The instantaneous hit rate, assuming an interval of \SI{1695}{\ns} between bunches, is: \begin{equation} - \frac{0.27}{1695\times 10^{-9}} = \SI{159e3}{\Hz} + \frac{0.27}{1695\times 10^{-9}} = \SI{158.9e3}{\Hz} \end{equation} -\section{Timing of hits on STM detector} -\label{sec:timing_of_hits_on_stm_detector} +The uncertainty on the hit rate estimation is \SI{2.6}{\percent} if +only statistical uncertainty of the hit counting in \cref{eqn:stm_hit_count} is +taken into account. This hit rate is too high for a HPGe detector to function +well, so an attenuator would be installed upstream of the spot-size collimator +to lower the hit rate to about \SI{10}{\kHz}. -\section{Signal to background ratio} -\label{sec:signal_to_background_ratio} +\subsection{Hit timing on STM detectors} +\label{sub:timing_of_hits_on_stm_detectors} +Timing in the simulation starts from the birth of a primary proton, which means +all events start at the same $t = 0$ time. In order to mimic the pulse +structure of the proton beam (\SI{250}{\ns} pulse width, \SI{1695}{\ns} between +pulses~\cite{Bartoszek2014}), the recorded times on each event are smeared by +a Gaussian distribution with a $\sigma = 250 / 6 = \SI{41.7}{\ns}$. + +The hit timing as a function of kinetic energy for several virtual detectors +are shown in \cref{fig:ke_time_4vds}. Most of hits arrive between +\num{100} and \SI{400}{\ns} from the center of a proton pulse. Only a few of +particles could hit the STM detectors, especially in the energy region around +the $2p-1s$ peak, that it is hard to investigate the +dependence between timing and energy of hits. Therefore I will only analyze the +timing information of hits STM\_SpotSizeCollUpStr. + +\begin{figure}[htbp] + \centering + \includegraphics[width=1.0\textwidth]{figs/ke_time_4vds} + \caption{Hit timing as a function of kinetic energy at spot size + collimator upstream (top left) and down stream (top right), and two STM + detectors (bottom left and right).} + \label{fig:ke_time_4vds} +\end{figure} + +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% +\subsection{Signal to background ratio: $2p-1s$ peak at spot-size collimator + upstream} +\label{sub:signal_to_background_ratio_2p_1s_peak_at_spot_size_collimator_upstream} +The energy of muonic $2p-1s$ transition in aluminum is given as \SI{335}{\keV} +by Geant4. Background is taken as the average counts for 10 bins around +\SI{335}{\keV}, and signal strength is calculated by subtracting the background +from the count under the peak. Energy spectra at spot-size +collimator upstream (VD 101: STM\_SpotSizeCollUpStr) in \SI{50}{\ns} windows +and their signal-to-background ratios are shown in +\cref{fig:ke_SpotSizeCollUpStr_time_slices}. +\begin{figure}[htbp] + \centering + \includegraphics[width=1.0\textwidth]{figs/ke_SpotSizeCollUpStr_time_slices} + \caption{Energy spectra at STM\_SpotSizeCollUpStr and signal-to-background + ratios in 50-ns time windows.} + \label{fig:ke_SpotSizeCollUpStr_time_slices} +\end{figure} + +\subsection{Signal to background ratio: \SI{1809}{\keV} at spot-size collimator +upstream} +\label{sub:signal_to_background_ratio_1809_kev_at_spot_size_collimator_upstream} -Muonic X-rays and probabilities in the simulation are not correct, see -\cref{sec:muonic_x_rays_in_geant4}. %%%% Appendices +\pagebreak \appendix \section{How to run the simulation and analyze data} +%%%%%%%%%%%%%%%%%%% \label{sec:how_to_run_the_simulation_and_analyze_data} +\subsection{Simulating beam flash} +\label{sub:simulating_beam_flash} +Simulation scripts are in: +\url{/mu2e/app/users/namtran/STM_study_201611/step00}: +\begin{itemize} + \item \url{fcl/step00.fcl}: configuration for this study (primary particles, + virtual detectors to be read out, particle filtering, ...) + \item \url{geom/geom.txt}: specify geometry settings (thickness + of shields, enabled virtual detectors, ...) + \item \url{submit.sh}: submit all jobs (5098) in the + \url{cd3-beam-g4s2-mubeam.0728a.list} to the grid +\end{itemize} +\noindent Steps to run the simulation: +\begin{itemize} + \item preparing user's code: follow Mu2e instruction to create an + \texttt{Offline} distribution (mine is at + \url{/mu2e/app/users/namtran/Offline}), + + \item setting up \texttt{mu2e} environment \footnote{I used \texttt{mu2egrid} + version \texttt{v3\_02\_00} which supports \texttt{mu2eart} command}: + \begin{mdframed}[style=listing] + \inputminted[ + fontsize=\scriptsize, + firstline=1, + lastline=11, + breaklines=true, + breakanywhere=true + ]{bash}{listings/runall.sh} + \end{mdframed} + + \item submitting all jobs: + \begin{mdframed}[style=listing] + \inputminted[ + fontsize=\scriptsize, + firstline=13, + breaklines=true, + breakanywhere=true + ]{bash}{listings/runall.sh} + \end{mdframed} +\end{itemize} + +\noindent Analysis code +\url{/mu2e/app/users/namtran/STM_study_201611/analysis}: +\begin{itemize} + \item \texttt{run\_statistics}: skims the log files (\texttt{mu2e.log} in + each subdirectory`) to make a list of successful runs, and collect CPU + time, random seeds. This script should be run first. + + \item \texttt{main.cc}: the analysis code, it is rather simple now, only + exports a few histograms from virtual detector hits. Run \texttt{make} + to produce the executable \texttt{read\_vd}. + \item \texttt{read\_vd}: takes a list of simulation outputs as input to + produce a single ROOT file which contains several histograms. +\end{itemize} + +%%%%%%%%%%%%%%%%%%% \section{Muonic X-rays in Geant4} \label{sec:muonic_x_rays_in_geant4} The muonic energy levels and transition probabilities were calculated using @@ -216,7 +348,7 @@ a simple model described by Mukhopadhyay~\cite{Mukhopadhyay.1977}. % language=c++, firstline=64, lastline=93,firstnumber=64, % breaklines=true, breakatwhitespace=true, % frame=single]{listings/G4EmCaptureCascade.cc} - \begin{mdframed} + \begin{mdframed}[style=listing] \inputminted[ breaklines=true, stepnumber=5, @@ -227,7 +359,7 @@ a simple model described by Mukhopadhyay~\cite{Mukhopadhyay.1977}. \end{mdframed} \item Energy of K-shell muons are calculated from energy of K-shell electrons: - \begin{mdframed} + \begin{mdframed}[style=listing] \inputminted[ breaklines=true, stepnumber=5, @@ -238,7 +370,7 @@ a simple model described by Mukhopadhyay~\cite{Mukhopadhyay.1977}. \end{mdframed} \item Energies of muons on other shells are calculated by scaling from that of K-shell muons: - \begin{mdframed} + \begin{mdframed}[style=listing] \inputminted[ breaklines=true, stepnumber=5,