\documentclass{article}

% Language setting
% Replace `english' with e.g. `spanish' to change the document language
\usepackage[english]{babel}
\usepackage{csquotes}

% Set page size and margins
% Replace `letterpaper' with`a4paper' for UK/EU standard size
\usepackage[top=2cm,bottom=2cm,left=2cm,right=2cm,marginparwidth=1.75cm]{geometry}

% Useful packages
\usepackage{amsmath}
\usepackage{graphicx}
\usepackage[colorlinks=true, allcolors=blue]{hyperref}
\usepackage[printonlyused,nohyperlinks]{acronym}
\usepackage{wrapfig}
\usepackage{subcaption} % \captionof
\usepackage{lastpage}
\usepackage{siunitx}
\usepackage[]{todonotes} %\todo[disable,inline,color=green!40]{}  \missingfigure[width=\textwidth]{\ldots} \listoftodos

\newcommand{\dd}{\mathrm d}
\newcommand{\solphys}{Solar Physics}
\newcommand{\aap}{Astronomy and Astrophysics}
\newcommand{\aaps}{Astronomy and Astrophysics Supplemental}
%---------------------------------------------------------------------------------
%AHEPaM-specific part starts here:
%---> insert the document's name and other information here
\newcommand{\docname}{cau-ath-spc-0005\_i1-0}
\newcommand{\issue}{1.0}
\newcommand{\issuedate}{2023-06-15}
\newcommand{\docstatus}{released}
\newcommand{\doctype}{Requirements}
%---------------------------------------------------------------------------------

\usepackage{fancyhdr}
\setlength{\headsep}{15mm}
\parindent0pt
\topmargin=-2.cm
\oddsidemargin=.5cm
\textwidth=16.0cm
\textheight=24.cm
\pagestyle{fancy}
\fancyhf{} % clear all fields
\fancyhead[L]{%
  \begin{tabular}[H]{l@{}}
  \vspace*{-10mm}\includegraphics[height=10mm]{shared/cau-colors.jpeg}
  \end{tabular}}
\fancyhead[R]{%
  %\scshape
  \begin{tabular}[t]{l@{}l@{}l@{}}
%----> Insert dates here:
  page: \thepage/\pageref{LastPage}\\issue: \issue\\date: \issuedate
  \end{tabular}}
\fancyhead[C]{%
  %\scshape
  \begin{tabular}[t]{l@{}l@{}l@{}}
%----> Insert document name here    
  Project: AHEPaM\\Doc. Title: Heritage File\\ Doc. ID: \docname
  \end{tabular}}
\fancyfoot[C]{\thepage/\pageref{LastPage}}




\usepackage[backend=biber,style=numeric, defernumbers=true, sorting=none]{biblatex}
\addbibresource{shared/sample.bib} %Imports bibliography file
%\bibliography{sample}

%%%%%%%%%%%%%%%%%
%
%   NOTE: To include a bibliography, need to use biber, not bibtex! This allows you to split into applicable and reference documents. See sample.bib on how to handle that.
%
%   biber CAU-ATH-XXXX-XXXX-i-Y.Y
%
%   if you add references to the bib file (and cite them) you probably need to delete the .aux file before recompiling
%
%   More information can be found here: https://en.wikibooks.org/wiki/LaTeX/Bibliographies_with_biblatex_and_biber
%
%%%%%%%%%%%%%%%%



\begin{document}
\begin{titlepage}
\thispagestyle{fancy}
\vspace*{2cm}
%---> Change Title of Document here
    {\bf \Large AHEPaM Heritage File} \vspace{2cm}\\
    \includegraphics[width=\textwidth]{shared/ahepam-title.png} 
\vspace{3cm}
\vfill

%---> Change fields as required. Entries are defined around line 25 (above). 
Prepared by: Bernd Heber\\
Document type: \doctype\\
Reference: \docname\\ 
Issue/Revision: \issue\\
Date of Issue: \issuedate\\
Status: \docstatus

\end{titlepage}
\setcounter{page}{2}

%---> change abstract as required
\begin{abstract}\normalsize
This document summarizes the existing heritage for AHEPaM based on Cosmic Ray
Instrument developments. It may consist of a summary technical note and a
collection of publications and presentations.
\end{abstract}

%\newpage

%\bibliographystyle{plain}
%This is where the bibliography is included. biber can also handle other keywords.
\printbibliography[keyword={applicable}, title={Applicable Documents}]
\printbibliography[keyword={reference}, title={Reference Documents}]


%\section{Applicable \& Reference Documents}
%\input{refdocs}
\newpage

\section*{Change Log}
%---> Please keep track of changes you made! Indicate them here.

\begin{tabular}{|p{2cm}|p{2cm}|p{10cm}|}\hline\hline
  Issue & Date & Affected page(s), chapter(s), \ldots \\\hline\hline
  1.0 & 2023-06-15 & initial version \\\hline
  \hline
  \end{tabular}

\newpage
\section*{List of Abbreviations and Acronyms}
\input{shared/ahepam-acronyms}
%--- If you use a new acronym, please define it in theis file and update it!

\newpage
\section{Construction of the \ac{AHEPaM}}
The \ac{AHEPaM} is designed to measure the energetic proton, helium and electron flux in the energy range from below 100~MeV/nucleon and above 2~GeV/nucleon for ions and from below 100 MeV to above 1 GeV and electrons, respectively, as discussed in the \ac{AHEPaM} measurement requirements given in \cite[]{sci-req-esa}. For this purpose it utilizes different measurement principles: 
\begin{description}
\item[dE/dx-E-method:]
This method is the most-commonly used multilayer-detector method to identify ions and electrons based on at least two energy deposits, one in a thin detector transmitting and another one in a thick detector stopping the incident particle. When the energy deposit in the thin detector is plotted against the total energy deposit, different ion species produce well-resolved tracks that are separated from the electron ''cloud''. The dE/dx-E-method only works for the lower energy range that \ac{AHEPaM} shall cover and has been successfully applied by the \ac{EPHIN} and \ac{HET} aboard \ac{SOHO} and Solar Orbiter, respectively. For details see M\"uller-Mellin et al. \cite[]{Mueller-Mellin-etal-1995} and Pacheco etal. \cite[]{Pacheco-etal-2020}. 
\item[dE/dx-dE/dx-method:] 
The dE/dx vs. dE/dx method extends the dE/dx vs. E-method to higher energies and relies on the ionization loss of a particle in several detectors. Plotting the energy loss in two adjacent detectors against each other, the mean energy losses of ions follow characteristic tracks. This is used to identify the particle species in certain areas of the two-dimensional energy loss plane \cite[]{Kuehl-etal-2019}. The critical issue with this method is the size of the instrument. I.e. the amount of active material needs to be chosen that protons and helium can be separated from each other \parencite[]{Heber-1997}. Therefore the \ac{AHEPaM} as sketched in Fig.~\ref{fig:ahepam-sketch}.
\begin{figure}
    \centering
    \includegraphics[width=0.9\columnwidth]{cau-ath-spc-0005_i1-0/figures/bgo90-telescope_iso-transp2}
    \caption{Sketch of the \ac{AHEPaM} including both BGOs (purple), Cherenkov detectors (white boxes) and SSDs (grey).}
    \label{fig:ahepam-sketch}
\end{figure}
%
\begin{figure}
    \centering
    \includegraphics[width=\columnwidth]{cau-ath-spc-0005_i1-0/figures/HET-de-dx.png}
    \caption{Ratio of the energy loss in the front and back telescopes of \ac{HET} as a function of the energy loss in the calorimeter. The two left-most fish-like structure is due to protons and helium penetrating the \ac{HET}.}
    \label{fig:HET-dE-dx}
\end{figure}
utilized a similar design as the \ac{HET} aboard the Solar Orbiter mission \cite[]{Pacheco-etal-2020}. Fig.~\ref{fig:HET-dE-dx} displays the results for penetrating ions. The energy resolution of such an instrument needs to be determined by \ac{GEANT4} simulations and accelerator calibration runs. In order to minimize a potential electron contribution to the proton distribution Aerogel Cherenkov detectors are inserted between the first and last two \acp{SSD}, respectively.   
\item[Aerogel Cherenkov threshold detector:] Another way to separate the different ions from each other and especially from electrons is to add a Cherenkov detector as included in the E6 aboard Helios \cite[]{Marquardt-2019}. This method is known as the dE/dx-C method. However, the energy loss is nearly constant for relativistic particles. This problem has been tackled by the \ac{KET} by introducing a threshold Cherenkov detector made of aerogel that allows the separation of protons above 2 GeV from protons with lower energies and protons below 2 GeV from electrons \cite[]{Heber-1997}. The same Ansatz is used for the \ac{AHEPaM}.
\item[Shower detector:] The \ac{KET}  utilizes in addition to the aerogel Cherenkov detector a second Cherenkov detector that was made from PbF$^2$ \cite[]{Simpson-etal-1992}. This detector acts as a shower calorimeter resulting in a larger  number of photons for electrons than for protons. For \ac{AHEPaM} the PbF$^2$ Cherenkov detector is replaced by a \ac{BGO} detector like in Solar Orbiter \ac{HET} that can be read out by compact photo diodes allowing to build a compact enclosure of the calorimeter.
\end{description}
\section{Heritage from previous  missions at the \ac{CAU}}
\begin{figure}
    \centering
    \includegraphics[width=\columnwidth]{figures/EPHIN-KET-MSL-HET.png}
    \includegraphics[width=\columnwidth]{cau-ath-spc-0005_i1-0/figures/TRLtable.png}
    \caption{Upper panels: Heritage instruments made in Kiel. From left to right: \ac{SOHO}/\ac{EPHIN} \cite[]{Mueller-Mellin-etal-1995}, Ulysses/\ac{KET} \cite[]{Simpson-etal-1992}, \ac{MSL}/\ac{RAD} \cite[]{hassler-etal-2012}, and Solar Orbiter \ac{HET} \cite[]{Pacheco-etal-2020}. The latter is combined with EPT, HET is the left part of the instrument with the circular red-tag cover. 
    The lower table gives the \ac{TRL} for each measurement principle used in \ac{AHEPaM}. }
    \label{fig:Instruments}
\end{figure}
The \ac{IEAP} (former \ac{IFKKI}) at the \ac{CAU} was \ac{PI} or \ac{CO-I} for several particle telescopes aboard different \ac{ESA} and \ac{NASA} missions. \ac{AHEPaM} gain heritage for different aspects like 
\begin{enumerate}
    \item Sensor development
    \item Mechanical development
    \item Space electronics
    \item Data processing 
\end{enumerate}
not only from them but also from successful balloon experiments within the \ac{BEXUS} program.

\paragraph{\ac{EPHIN}}
The \acf{EPHIN} was designed at the \ac{CAU} in order to measure electrons and protons and helium in the energy range from a few 100 keV to about 10 MeV and a few MeV/nucleon to above 50~MeV/nucleon, respectively \cite{Mueller-Mellin-etal-1995}. It also should provide the flux of hydrogen and helium isotopes in the same energy range. The separation of isotopes becomes only possible when  using \textbf{sectorized \acp{SSD}} as proposed for \ac{AHEPaM}. This has been successfully applied as shown for example in Gomez-Herrero et al. \cite{Gomez-Herrero-etal-2000}. 
\begin{figure}
    \centering
    \includegraphics[width=0.49\textwidth]{cau-ath-spc-0005_i1-0/figures/Sketch-EPHIN.png}
    \includegraphics[width=0.49\textwidth]{cau-ath-spc-0005_i1-0/figures/Sketch-KET.png}
    \caption{Sketch of the \ac{EPHIN} and \ac{KET} sensor heads (adapted from \cite{Kuehl-etal-2019} and \cite{Simpson-etal-1992}). }
    \label{fig:Sketch-EPHIN-KET}
\end{figure}
In order to achieve a large geometrical factor \ac{AHEPaM} relies on \textbf{large \acf{SSD}}. Although not sectorized one \ac{SSD} in the \acf{EPHIN} had an active area of $A=5000$~mm$^2$ (see Fig.~\ref{fig:Sketch-EPHIN-KET}). Among all \acp{SSD} this detector is working nominal since 27~years. Thus heritage to mount and operate large \acp{SSD} exist at the institution.

\paragraph{\ac{HET}} 
The heritage from the \ac{EPD} suite aboard Solar Orbiter especially the  \ac{HET} are manifold: 
\begin{description}
\item[Analog and digital electronics:] For \ac{AHEPaM} with the exception of the \ac{HV} we will utilize the same concept for the electronics of \ac{HET} successfully operating on Solar Orbiter. 
\item[\ac{BGO}-scintillator:] Measurements from the \ac{HET} on Solar Orbiter show that the \ac{BGO} is well suited to measure the energy loss of near and relativistic protons and helium with minor corrections for the quenching effect (\cite[]{Wimmer-etal-2021,Pacheco-etal-2020}).
\item[Electronics:] \ac{AHEPaM} foresees to use the same electronic chain as \ac{HET}, including major parts of the analog and digital electronics. Exceptions are the handling of the \acfp{PMT} that has been utilized during several different balloon flights within the \ac{BEXUS} campaigns.
\item[Data processing:] The data processing of \ac{AHEPaM} will be inspired by the one of \ac{HET}.
\item[Mechanical Design:] Several mechanical features of \ac{HET} can be adapted to \ac{AHEPaM}. 
\end{description}
\paragraph{\ac{KET}}
The \acf{KET} aboard Ulysses corresponds to a one sided \ac{AHEPaM} with two exceptions. 
\begin{enumerate}
    \item The calorimeter of the \ac{KET} is made by a PbF$^3$ Cherenkov-Detector and surrounded by a plastic scintillator not from two \ac{BGO} scintillation and  
    \item The instrument utilizes an plastic scintillator as anticoincidence detector.
\end{enumerate}
A sketch of the \ac{KET} sensor head is shown in Fig~\ref{fig:Sketch-EPHIN-KET}. It has proven that measurements of protons in the energy range between 30~MeV and 2~GeV \cite[]{Heber-etal-1996,Gieseler-Heber2016}
\begin{description}
\item[Aerogel cherenkov detector:] The \ac{KET} aboard Ulysses utilized an aerogel Cherenkov detector as threshold detector as foreseen in the \ac{AHEPaM} successfully. 
\end{description}
\paragraph{\ac{BEXUS}}
The \ac{BEXUS} programme allows students from universities and higher education colleges across Europe to carry out scientific and technological experiments on research balloons. The institute had been part of the following flights: 
\begin{description}

\item[\ac{FaNS}] on \ac{BEXUS}-31. The \ac{FaNS} has been developed to determine the flux of fast neutrons within the Earth's atmosphere. The instrument consists of a boron-doped plastic scintillator which is optimized for the energy range from about 0.5~MeV to above 10~MeV \cite[]{FANS-2021}.

\item[\ac{TANOS}] on \ac{BEXUS}-29. In order to measure thermal neutrons in the atmosphere the team developed an instrument consisting of a silicon detector stack and two layers of gadolinium foil between two detectors. The cross section of gadolinium is very high for thermal neutrons, around 49000 barn, thus this material is particularly suitable for the experiment \cite[]{TANOS-2019}.

\item[\ac{ADAM}] on \ac{BEXUS}-19. To determine the angular distribution of charged particles during a \ac{BEXUS} balloon flight the team developed an instrument called \ac{EVA}. It consists of \cite[]{Martensen-etal-2015}:
\begin{itemize}
    \item a sensor head, which will include 16 silicon based \acp{SSD}, also to be referred to as photodiodes. Each of the \acp{SSD} can detect incoming particles individually causing a little voltage peak that can be read out by the second part
    \item a data acquisation system from our institute called \ac{IRENA}, a new developed 18-channel-charge-sensitive-preamp-board and several other electronic boards that provide an infrastructure for the \ac{IRENA} (Ethernet, USB, RS232, power).
\end{itemize}

\item[\ac{MONSTA}] on \ac{BEXUS}-14. The team used the \ac{PING} on the stratospheric balloon to measure the height dependent flux of the neutral component. In order to determine the contribution of neutrons to the dose, it is essential to measure their altitude-dependent energy deposition spectra. The sensor head of \ac{PING} consists of two different scintillators: The inner plastic scintillator BC-412 and the surrounding inorganic scintillator CsI(Na). The scintillators are optically coupled and are read out by a common \ac{PMT}. Neutrons deposit mostly their energy in the hydrogen rich BC-412 plastic scintillator while the heavy inorganic scintillator has a high cross-section for gamma rays. Because of their different decay times, the pulses of the two scintillators have a different pulse shape. Hence, they can be separated by applying pulse shape analysis \cite[]{Scharrenberg-etal-2013}. 

\item[\ac{RETA}] on \ac{BEXUS}-13. In order to investigate the radiation environment in the atmosphere  a particle telescope consisting of four segmented silicon semiconductor detectors was developed. Due to the arrangement of the detectors, it is possible to separate neutral and charged particles and the calculated dose rates can be converted into a dose equivalent rate which is the unit for radiation protection. The \ac{FRED} has successfully made such measurements onboard a stratospheric balloon \cite[]{Moeller-etal-2011}. 
\end{description}
 
\begin{description}
\item[\ac{PMT} and \ac{HV}:] The two projects \ac{FaNS} and \ac{MONSTA} successfully utilized \acf{PMT} in order to read out several different scintillation detectors.   
\item[Spacecraft interfaces:] For all experiments interfaces to the balloon have been successfully provided by the institute.
\item[Mechanical design:] Large CSI and plastic detectors have been utilized by \ac{MONSTA} successfully
\end{description}
\end{document}