diff --git a/figures/mm.png b/figures/mm.png new file mode 100644 index 0000000000000000000000000000000000000000..c77aafa338f99ed9f28e04d97120b71b705d2122 Binary files /dev/null and b/figures/mm.png differ diff --git a/figures/triangle.png b/figures/triangle.png new file mode 100644 index 0000000000000000000000000000000000000000..fbc5e7b4a77b2661e93e1ba960e8fa5672bd91aa Binary files /dev/null and b/figures/triangle.png differ diff --git a/tetra.tex b/tetra.tex index ecfccbc759866d3d8e4d30041fa7215020714a65..1fa0dbbddec63255d31fd2979fc3e1292c5d18f4 100644 --- a/tetra.tex +++ b/tetra.tex @@ -38,6 +38,8 @@ The beam particles were identified by two plastic scintillators, which allowed t %For the beam particle identification and its energy determination two plastic scintillators were used. The trajectories the beam projectiles were tracked by two pairs of multi-wire proportional chambers. The cryogenic target was filled with a deuterium gas at 27\,K of atmospheric pressure. +The special run with the empty target cell was conducted to estimate the background conditions, which had $\approx$16\% of the total $^8$He beam time. + Detection of the charged reaction products was realized by $\Delta E$-$E$ telescopes. The latter allowed to identify $^6$Li with clear separation from other registered lithium isotopes. %The side assembly of three (20\,$\mu$m, 1\,mm and 1\,mm thick) silicon strip detector (SSD) telescope, and the front telescope made of the 1.5\,mm double side SSD coupled to the CsI(Tl) scintillator array. @@ -74,6 +76,33 @@ We make a suggestion that these gammas are produced by the interaction of the ne \end{figure} %------------------------------------------------------------------------------- +Tetranuetron was reconstructed from the recoil $^6$Li as a missing component in $^2$H($^8$He,$^6$Li) reaction. +The total number of $^6$Li-neutron coincidences found in the recorded data was 136. +But, due to the kinematic selection, only 108 of these events were identified as the population of 4n. +The correlation we used for this selection is shown in Fig.\ \ref{fig:mm_4n} (b). +This is the correlation of the neutron kinetic energy in the 4n center-of-mass frame with the reconstructed energy $E_T$. +The fact that the most events are located below the kinematic border proves the good channel identification of the studied reaction. +Another evidence for the 4n population is that the data collected with the empty target has zero events satisfying the used selections. +The missing mass (MM) spectrum of 4n reconstructed after kinematic selection is shown in Fig.\ \ref{fig:mm_4n} b). + +%------------------------------------------------------------------------------- +\begin{figure} + \centering + \begin{tabular}{cc} + \includegraphics[width=0.5\linewidth]{figures/triangle} + & + \includegraphics[width=0.5\linewidth]{figures/mm} \\ + (a) & (b) + \end{tabular} + \caption{ + (a) The dE-TAC correlation providing clear separation of gammas from neutrons. + (b) The ToF distribution. + The set of three peaks on the left corresponds to the gammas produced in the diaphragm installed 20 cm upstream the target plane, target frame, and CsI(Tl) array. + Green ad red-line histograms formed by the events, identified as gamma/neutron by the dE-TAC method. + } + \label{fig:mm_4n} +\end{figure} +%------------------------------------------------------------------------------- \section{Conclusion}