diff --git a/figures/gamma-n.png b/figures/gamma-n.png new file mode 100644 index 0000000000000000000000000000000000000000..86878c20c9c0422109452178294080c31c0e9863 Binary files /dev/null and b/figures/gamma-n.png differ diff --git a/figures/tof.png b/figures/tof.png new file mode 100644 index 0000000000000000000000000000000000000000..b1179d6251ec1bb4271f082ccaebb7696c26bbb9 Binary files /dev/null and b/figures/tof.png differ diff --git a/tetra.tex b/tetra.tex index 9f2dd951f57a39fdf6944dfd18dcd3b3151a67fb..ecfccbc759866d3d8e4d30041fa7215020714a65 100644 --- a/tetra.tex +++ b/tetra.tex @@ -30,23 +30,50 @@ This work is dedicated to the results on the $^2$H($^8$He,$^6$Li) reaction studi \section{Experiment} ACCULINNA-2 facility, FLNR, JINR, produced 26\,AMeV $^{8}$He and focused it on the cryogenic deuterium target. -The detection system was intended to measure the product of the $^2$H($^8$He,$^4$He)$^6$H reaction and further $^6$H$\rightarrow^3$H+3n decay. -The employed detector system is described in Ref.\ \cite{Nikolskii:2022}. +The experiment was dedicated to $^{7}$H studies, see Ref.\ \cite{Muzalevskii:2021}, but the detection system allowed to measure the product of the $^2$H($^8$He,$^6$Li)4n reaction and further neutron decay. +The employed detector system is widely described in Ref.\ \cite{Muzalevskii:2021}. -For the particle identification (PID) of the beam two plastic scintillators were used, which allowed to measure the energy of the projectile from its time-of-flight (ToF) and identify the isotope by the dE-ToF method. +The beam particles were identified by two plastic scintillators, which allowed to measure the energy of the projectile from its time-of-flight (ToF). %The particle identification (PID) of the beam was performed by the dE-ToF %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. -For the detection of the charged reaction products two types of $\Delta E$-$E$ telescopes were used. -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. -The thin, 20\,$\mu$m detectors in the side telescopes allowed one to reliably identify and reconstruct low-energy particles (the recoil $^4$He nuclei with energy $\ge$5\,MeV), see Ref.\ \cite{Muzalevskii:2020}, emitted from the target in the laboratory angular range between $8^{\circ}$ and $26^{\circ}$. +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. +%The thin, 20\,$\mu$m detectors in the side telescopes allowed one to reliably identify and reconstruct low-energy particles (the recoil $^4$He nuclei with energy $\ge$5\,MeV), see Ref.\ \cite{Muzalevskii:2020}, emitted from the target in the laboratory angular range between $8^{\circ}$ and $26^{\circ}$. %The first one covered the laboratory angular range between $8^{\circ}$ and $26^{\circ}$ and allowed to identify and reconstruct low-energy particles, see Ref.\ \cite{Muzalevskii:2020}. -The front telescope covered angles $\leq9^{\circ}$ and was used to measure the high-energy particles (tritons with energy up to 160\,MeV), stopping them in the CsI(Tl) crystal. -Neutron detection was realized by the time-of-flight (ToF) stilbene modules \cite{Bezbakh:2018}.%, which provides reliable neutron-gamma separation and measure the particle energy. +%The front telescope covered angles $\leq9^{\circ}$ and was used to measure the high-energy particles (tritons with energy up to 160\,MeV), stopping them in the CsI(Tl) crystal. +Neutron were detected by the ToF stilbene modules \cite{Bezbakh:2018}, which provides clear neutron-gamma separation and allow to calculate the particle energy from its ToF. + +%The neutron identification was realized \section{Results} +The most important part of the $^2$H($^8$He,$^6$Li)4n reaction analysis was neutron identification and reconstruction. +The dE-TAC correlation presented Fig.\,\ref{fig:ND_id} (a) shows that the signals produced by gamma and neutron interaction with detector material are well separated. +However, the selection each of them on the ToF distribution, see Fig.\,\ref{fig:ND_id} (b) leads to the suggestion that some gamma-type signals correspond to neutron-like ToF. +We make a suggestion that these gammas are produced by the interaction of the neutrons with the stilbene housing and that is why can be considered as neutron events. + +%------------------------------------------------------------------------------- +\begin{figure} + \centering + \begin{tabular}{cc} + \includegraphics[width=0.52\linewidth]{figures/gamma-n} + & + \includegraphics[width=0.48\linewidth]{figures/tof} \\ + (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:ND_id} +\end{figure} +%------------------------------------------------------------------------------- + \section{Conclusion}