diff --git a/cau-ath-er_i1-0/GCR-spectra.pdf b/cau-ath-er_i1-0/GCR-spectra.pdf new file mode 100644 index 0000000..76e3c02 Binary files /dev/null and b/cau-ath-er_i1-0/GCR-spectra.pdf differ diff --git a/cau-ath-er_i1-0/report.tex b/cau-ath-er_i1-0/report.tex index d93aa1d..e8166c4 100644 --- a/cau-ath-er_i1-0/report.tex +++ b/cau-ath-er_i1-0/report.tex @@ -50,24 +50,13 @@ This executive report summarizes the findings of the work performed at \acs{CAU} Helium & & \\\hline & & \\\hline \end{tabular} - \caption{Key properties of AHEPAM.} + \caption{Key properties of \acs{AHEPaM}.} \label{tab:key-properties} \end{table} \section{AHEPaM Design} -The design of \acs{AHEPaM} was driven by the original measurement requirements which are summarized in Tab.~\ref{tab:orig-meas-req}. The statistical accuracy of 1\% in 2 energy bands within 3 ks for protons and 5\% for electrons in the ~1 GeV energy range determined the size, and thus mass, and envelope of \acs{AHEPaM}. Figure~\ref{fig:GCR-spec} shows typical \acs{GCR} spectra of protons and electrons as well as two straight-forward fits of a force-field solution to the data. The peak flux of protons can be seen as between one and two particles per m$²$ - -The large energy range to be covered includes relativistic, highly penetrating particles... - -\begin{figure} - \centering - \includegraphics{cau-ath-er_i1-0/adriani-etal-combined-e-p.png} - \caption{Measurements of galactic cosmic ray protons and electrons and fitted force field solutions.} - \label{fig:GCR-spec} -\end{figure} - \begin{table}[] \centering \begin{tabular}{|c|c|c|c|c|} \hline\\ @@ -83,6 +72,24 @@ The large energy range to be covered includes relativistic, highly penetrating p \label{tab:orig-meas-req} \end{table} +The design of \acs{AHEPaM} was driven by the original measurement requirements which are summarized in Tab.~\ref{tab:orig-meas-req}. The statistical accuracy of 1\% in 2 energy bands within 3 ks for protons and 5\% for electrons in the ~1 GeV energy range determined the size, and thus mass, and envelope of \acs{AHEPaM}. Figure~\ref{fig:GCR-spec} shows typical \acs{GCR} spectra of protons and electrons as well as two straight-forward fits of a force-field solution to the data. The peak flux of protons (at about 0.5 GeV) can be seen as a few thousand particles per (m$²$ s sr GeV). The flux of electrons is approximately 2\% of that, similar to that of Helium ions. The large energy range to be covered by \acs{AHEPaM} requires a substantial amount of matter to slow down particles. + +\begin{figure} + \centering + \includegraphics{cau-ath-er_i1-0/GCR-spectra.pdf} + \caption{Measurements of galactic cosmic ray protons (red), electrons (green) and corresponding model fits (green, Helium).} + \label{fig:GCR-spec} +\end{figure} + +Energetic particles are typically measured with so-called particle telescopes which combine different kinds of detectors to measure the energy that a particle deposits in the detector. A clever combination allows to determine the particle energy and determine what kind of particle (electron, proton, $\alpha$-particle) it was. Particles in the energy range to be covered by \acs{AHEPaM} typically loose only a fraction of their energy in a detector, this can be approximated by eq.~\ref{eq:bethe-bloch}, given below\footnote{The energy deposited in a detector can be modeled much more accurately with the sophisticated \acs{GEANT4} simulation package which was developed at \acs{CERN} \cite{agostinelli-etal-2003}. This software package was used extensively in the development of \acs{AHEPaM}.}, +\begin{equation} +\frac{{\rm d}E}{{\rm d}x} \sim \frac{Z^2 n_e}{E}, + \label{eq:bethe-bloch} +\end{equation} +where $E$ is the particle kinetic energy, $Z$ its nuclear charge, and $n_e$ is the electron density in the detector material, and d$x$ the detector thickness. For example, a 500 MeV proton looses less than 100 keV in a typical silicon solid-state detector (\acs{SSD}). This means that the total energy of a particle in the required energy range can not be measured within a reasonably-sized detector. That the deposited energy is proportional to $Z^2$ assures that protons and Helium nuclei can easily be distinguished. The difficulty lies in separating electrons from protons. If a particle is faster than the speed of light in the detector, it produces Cherenkov radiation. Because electrons in the required energy range basically travel at the speed of light in vacuum, \acs{AHEPaM} also uses this measurement technique to discriminate electrons from protons because the latter are much slower and therefore do not produce Cherenkov radiation. If the particle has enough energy, it can also produce a shower of secondary particles, an effect that is also used in \acs{AHEPaM}. Thus the driving requirements for \acs{AHEPaM} were the large energy range, the high counting statistics, and the discrimination between electrons and protons. These were met by using the combination of mutliple measurement techniques described in the following. + +To measure the low fluxes of \acs{GCR} particles \acs{AHEPAM} had to have a large collecting area, and a large field of view (\acs{FOV}), the product is equivalent to the "collecting power" or geometric factor. This is determined by the area of the front and rear detectors of the particle telescope, and by its length. The \acs{AHEPaM} developed in this contract maximizes the geometry factor by its compact design and by allowing to measu + Explain how we arrived at the current design. Justify. diff --git a/shared/sample.bib b/shared/sample.bib index a9702e3..c15b8f2 100644 --- a/shared/sample.bib +++ b/shared/sample.bib @@ -702,3 +702,16 @@ archivePrefix = {arXiv}, adsnote = {Provided by the SAO/NASA Astrophysics Data System} } +@ARTICLE{agostinelli-etal-2003, + author = {{Agostinelli}, S. and {Allison}, J. and {Amako}, K. and {Apostolakis}, J. and {Araujo}, H. and {Arce}, P. and {Asai}, M. and {Axen}, D. and {Banerjee}, S. and {Barrand}, G. and {Behner}, F. and {Bellagamba}, L. and {Boudreau}, J. and {Broglia}, L. and {Brunengo}, A. and {Burkhardt}, H. and {Chauvie}, S. and {Chuma}, J. and {Chytracek}, R. and {Cooperman}, G. and {Cosmo}, G. and {Degtyarenko}, P. and {Dell'Acqua}, A. and {Depaola}, G. and {Dietrich}, D. and {Enami}, R. and {Feliciello}, A. and {Ferguson}, C. and {Fesefeldt}, H. and {Folger}, G. and {Foppiano}, F. and {Forti}, A. and {Garelli}, S. and {Giani}, S. and {Giannitrapani}, R. and {Gibin}, D. and {G{\'o}mez Cadenas}, J.~J. and {Gonz{\'a}lez}, I. and {Gracia Abril}, G. and {Greeniaus}, G. and {Greiner}, W. and {Grichine}, V. and {Grossheim}, A. and {Guatelli}, S. and {Gumplinger}, P. and {Hamatsu}, R. and {Hashimoto}, K. and {Hasui}, H. and {Heikkinen}, A. and {Howard}, A. and {Ivanchenko}, V. and {Johnson}, A. and {Jones}, F.~W. and {Kallenbach}, J. and {Kanaya}, N. and {Kawabata}, M. and {Kawabata}, Y. and {Kawaguti}, M. and {Kelner}, S. and {Kent}, P. and {Kimura}, A. and {Kodama}, T. and {Kokoulin}, R. and {Kossov}, M. and {Kurashige}, H. and {Lamanna}, E. and {Lamp{\'e}n}, T. and {Lara}, V. and {Lefebure}, V. and {Lei}, F. and {Liendl}, M. and {Lockman}, W. and {Longo}, F. and {Magni}, S. and {Maire}, M. and {Medernach}, E. and {Minamimoto}, K. and {Mora de Freitas}, P. and {Morita}, Y. and {Murakami}, K. and {Nagamatu}, M. and {Nartallo}, R. and {Nieminen}, P. and {Nishimura}, T. and {Ohtsubo}, K. and {Okamura}, M. and {O'Neale}, S. and {Oohata}, Y. and {Paech}, K. and {Perl}, J. and {Pfeiffer}, A. and {Pia}, M.~G. and {Ranjard}, F. and {Rybin}, A. and {Sadilov}, S. and {Di Salvo}, E. and {Santin}, G. and {Sasaki}, T. and {Savvas}, N. and {Sawada}, Y. and {Scherer}, S. and {Sei}, S. and {Sirotenko}, V. and {Smith}, D. and {Starkov}, N. and {Stoecker}, H. and {Sulkimo}, J. and {Takahata}, M. and {Tanaka}, S. and {Tcherniaev}, E. and {Safai Tehrani}, E. and {Tropeano}, M. and {Truscott}, P. and {Uno}, H. and {Urban}, L. and {Urban}, P. and {Verderi}, M. and {Walkden}, A. and {Wander}, W. and {Weber}, H. and {Wellisch}, J.~P. and {Wenaus}, T. and {Williams}, D.~C. and {Wright}, D. and {Yamada}, T. and {Yoshida}, H. and {Zschiesche}, D. and {G EANT4 Collaboration}}, + title = "{G EANT4{\textemdash}a simulation toolkit}", + journal = {Nuclear Instruments and Methods in Physics Research A}, + year = 2003, + month = jul, + volume = {506}, + number = {3}, + pages = {250-303}, + doi = {10.1016/S0168-9002(03)01368-8}, + adsurl = {https://ui.adsabs.harvard.edu/abs/2003NIMPA.506..250A}, + adsnote = {Provided by the SAO/NASA Astrophysics Data System} +}