+\begin{center}
+\begin{pspicture}(-1,-1)(1,1)
+\def\Kernradius{7.5pt}
+\def\KernabstandHe{7.5pt}
+\def\ColorProton{red}
+\def\ColorNeutron{gray!20}
+
+\newpsstyle{proton}{linecolor={[rgb]{0.72 0 0}},slopebegin=red!50,sloperadius=0.15,linewidth=0.1pt,slopecenter=0.65 0.6,linestyle=solid}
+\newpsstyle{neutron}{linecolor=gray!50,slopebegin=white,sloperadius=0.11,linewidth=0.1pt,slopecenter=0.65 0.6,linestyle=solid}
+
+\def\Proton{\psBall[style=proton](0,0){\ColorProton}{\Kernradius}}
+\def\Neutron{\psBall[style=neutron](0,0){\ColorNeutron}{\Kernradius}}
+
+\def\AtomKernHe{%
+\multido{\iAngle=40+180}{2}{%
+\rput(\KernabstandHe;\iAngle){\Proton}%
+}%
+\multido{\iAngle=130+180}{2}{%
+\rput(\KernabstandHe;\iAngle){\Neutron}%
+}%
+}%
+\rput(0,0){\AtomKernHe}
+\rput(1.5,0){$^{4}_{2}$He$^{2+}$}
+\end{pspicture}
+\end{center}
+
+\subsection{Montage exp\'{e}rimental}
+