\section{Planned developments}
\label{sec:planned-developments}

\subsection{Developments}
\label{subsec:developments}
Besides the scope of the project to develop a demonstration model for \acs{AHEPaM} different breadboards will be build in order to support the development process.

\begin{enumerate}

        \item PMT instrumentation: The \ac{PMT} and its supply electronics, such as the high-voltage supply and the pre-amplifier, shall be sequentially tested for their functionality.\\
        The full high-voltage supply itself as well as the supply for each stage of the \ac{PMT} can easily be tested using a multimeter, utilizing a voltage divider to proportionally reduce the voltage and the current at the multimeter.\\

        To test the \ac{PMT} it has to be operated within a completely dark volume containing a regulated, pulsed light source. A plastic scintillator would be available to produce short light pulses of higher but comparable light intensity to the Cherenkov detectors aerogel. Atmospheric muons or any other kind of source for ionizing particles can be used to trigger a light pulse in the scintillator. The produced charge pulse in the \ac{PMT} shall be measurable with an oscilloscope between the \acp{PMT} anode and ground.\\
        
        The functionality of the pre-amplifier can be varified using the former described setup but using the pre-amplifier at the signal output of the PMT. An oscilloscope shall be used to measure the short term voltage increase at the output of the pre-amplifier when the scintillator is radiating light.\\
        
        \item PMT signal readout: The former described setup will finally also be used to test the functionality of the Cherenkov detector. Therefore the scintillator will be replaced by the aerogel. Cherenkov light needs to be triggered by particles faster than the speed of light in the medium. This threshold is most easily overcome by cosmic muons. The aerogel is placed between a silicon detector telescope so that the path of each muon detected by the telescope also had to pass through the aerogel. Most of the muons should trigger a Cherenkov signal in the aerogel, which should then be measured by the tested \ac{PMT} setup.

        %This threshold is most easily overcome by electrons with relatively low energies of \(>\sim2MeV \). %For that task we plan on using \(Sr^{90}\) source from the universities inventory. %as can be seen in figure \ref{fig:Sr90} 
       % Every \(\beta^{-}\) decay of \(Sr^{90}\) to \(Zr^{90}\) happens with an intermediate step to \(Y^{90}\) which decays with a relatively short half-life, most probably emitting an electron of an energy of  \(2.2 MeV\). 
%        \begin{figure}
%            \centering
%            \includegraphics{cau-ath-pla-0008_i1-0/media/Sr90.png}
%            \caption{Decay scheme of \(Sr^{90}\)}
%            \label{fig:Sr90}
%        \end{figure}
        
       % \item Cherenkov wrapping and mechanical support. \colorbox{yellow}{Lars}
        \item The simultaneously detector signal readout is well known and by data handling of previous missions. A difference in AHEPaM readout due to the large amount of signals is the ADC sampling of three signals via multiplexer with one ADC. The FEE that we designed for the DORN instrument aboard the Chinese Chang'E-6 lunar lander mission fulfills exactly these requirements.
        \url{https://cloud.rz.uni-kiel.de/index.php/s/TnJYqeJQKnKCm8C?path=AHEPAM}
   
    
\end{enumerate}