@@ -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.
(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.
