commit

add.tex

@@ -51,11 +51,11 @@
 		\includegraphics[width=0.45\linewidth]{figures/mm_full} 
 		&				
 		\includegraphics[width=0.45\linewidth]{figures/mm_ect} \\
-		a) Triton kinematical triangle & b) Spectrum for 1/2 cut-off \\
+		a) Inclusive spectrum D$_2$ target & b) Inclusive spectrum empty target \\
 		\includegraphics[width=0.45\linewidth]{figures/angular_full} 
 		&		
 		\includegraphics[width=0.45\linewidth]{figures/angular_ect} \\		
-		c) Reaction angle correlation & d) Spectrum with angular cut-off \\
+		c) Reaction angle correlation D$_2$ target & d) Reaction angle correlation empty target \\
 		
 	\end{tabular}
 	\caption{ 
@@ -72,7 +72,7 @@
 		\includegraphics[width=0.5\linewidth]{figures/triangle} 
 		&
 		\includegraphics[width=0.5\linewidth]{figures/triangle_ect} \\
-		(a) & (b)
+		(a) D$_2$ target & (b) Empty target 
 	\end{tabular}
 	\caption{
 		Neutron triangle. full and empty target
@@ -95,5 +95,175 @@
 \end{figure}
 %-------------------------------------------------------------------------------
 
+%-------------------------------------------------------------------------------
+\begin{figure}[t]
+	\begin{center}
+		\includegraphics[width=\textwidth]{figures/subtraction}
+	\end{center}
+	%
+	\caption{
+		Empty target data analysis. Green histograms - data collected with empty target. Empty target data is smoothed.
+		Top left: inclusive spectra; empty target data is normalized.
+		Top right: triangle cut spectra; empty target data is normalized.
+		Bottom left: inclusive spectrum after the subtraction.
+		Bottom right: Zoom 0-27 MeV of the inclusive spectrum after the subtraction.
+	}
+	%
+	\label{fig:ect_subtraction}
+\end{figure}
+%-------------------------------------------------------------------------------
+
+
+
+%-------------------------------------------------------------------------------
+\begin{figure}[t]
+	\begin{center}
+		\includegraphics[width=\textwidth]{figures/corr4N_7H}
+	\end{center}
+	%
+	\caption{
+		Three sets of triton kinematical triangle + 4n MM + 4n:7H correlation.
+	}
+	%
+	\label{fig:4n_alternative}
+\end{figure}
+%-------------------------------------------------------------------------------
+
+%-------------------------------------------------------------------------------
+\begin{figure}[t]
+	\begin{center}
+		\includegraphics[width=\textwidth]{figures/4N_7H_corr_empty}
+	\end{center}
+	%
+	\caption{
+		Empty target. Same three sets of triton kinematical triangle + 4n MM + 4n:7H correlation.
+	}
+	%
+	\label{fig:4n_alternative_ect}
+\end{figure}
+%-------------------------------------------------------------------------------
+
+%-------------------------------------------------------------------------------
+\begin{figure}[t]
+	\begin{center}
+		\includegraphics[width=\textwidth]{figures/4n_correlation1}
+	\end{center}
+	%
+	\caption{
+		4n-$^7$H MM correlation. 4n full spectrum. \\
+		4n MM if 8\,MeV<$^7$H<10\,MeV and 12\,MeV<$^7$H. 4n MM if 8\,MeV<$^7$H. \\
+		Green color corresponds to the empty target measurements.
+	}
+	%
+	\label{fig:4n_correlation}
+\end{figure}
+%-------------------------------------------------------------------------------
+
+%-------------------------------------------------------------------------------
+\begin{figure}
+	\centering
+	\begin{tabular}{cc}
+		\includegraphics[width=0.45\linewidth]{figures/bin1} 
+		&				
+		\includegraphics[width=0.45\linewidth]{figures/bin2} \\
+		a) Binning 1 & b) Binning 2 \\
+		\includegraphics[width=0.45\linewidth]{figures/bin3} 
+		&		
+		\includegraphics[width=0.45\linewidth]{figures/bin4} \\		
+		c) Binning 3 & d) Binning 4 \\
+		
+	\end{tabular}
+	\caption{ 
+		Binning of 4n MM spectra cuts.	
+	}
+	\label{fig:4n_binning}
+\end{figure}
+%-------------------------------------------------------------------------------
+
+
+%-------------------------------------------------------------------------------
+\begin{figure}[t]
+	\begin{center}
+		\includegraphics[width=\textwidth]{figures/tetra_momCorr1}
+	\end{center}
+	%
+	\caption{
+		4n MM from d-3He channel. 4n MM from d-6Li channel \\
+		4n momentum in antiLab vs 4n MM from d-3He channel. \\ 4n momentum in antiLab vs 4n MM from d-6Li channel. \\ 
+		Red color corresponds to the events with E$_T$($^{7}$H)>8 MeV.
+	}
+	%
+	\label{fig:tetra_momCorr1}
+\end{figure}
+%-------------------------------------------------------------------------------
+
+%-------------------------------------------------------------------------------
+\begin{figure}[t]
+	\begin{center}
+		\includegraphics[width=\textwidth]{figures/offsetTest}
+	\end{center}
+	%
+	\caption{
+		Full 4n MM from d-3He with different bin offsets.
+	}
+	%
+	\label{fig:offsetTest}
+\end{figure}
+%-------------------------------------------------------------------------------
+
+
+
+
+%-------------------------------------------------------------------------------
+\begin{figure}[t]
+	\begin{center}
+		\includegraphics[width=\textwidth]{figures/subract1}
+	\end{center}
+	%
+	\caption{
+		Top left: correlation E$_{T}$(4n) vs E$_{T}$($^7$H). Green color corresponds to the empty target. \\
+		Middle left: chosen area for analysis. Zoomed. \\ 
+		Top right: E$_{T}$(4n) obtained by projection of Middle left distribution to the left axis. \\
+		Middle right: E$_{T}$(4n) obtained by projection of the chosen area in suggestion of the homogeneously layout of the green events inside the area. Factorized by the beam factor 6. \\
+		Bottom right: E$_{T}$(4n) after subtraction.
+	}
+	%
+	\label{fig:sub1}
+\end{figure}
+%-------------------------------------------------------------------------------
+
+%-------------------------------------------------------------------------------
+\begin{figure}[t]
+	\begin{center}
+		\includegraphics[width=\textwidth]{figures/subract2}
+	\end{center}
+	%
+	\caption{
+		The chosen area was changed to choose the events with E$_{T}$($^7$H)>8 MeV only. The same logic was applied with the modified area.
+	}
+	%
+	\label{fig:sub2}
+\end{figure}
+%-------------------------------------------------------------------------------
+
+\newpage
+\thispagestyle{empty}
+
+Был сделан анализ фоновых событий, основываясь на двумерке E$_{T}$(4n) vs E$_{T}$($^7$H).
+То есть, на распределении E$_{T}$(4n) vs E$_{T}$($^7$H) Рис \ref{fig:sub1} (левый верх) выбиралась рабочая область.
+Отдельно события вошедшие в рабочую область и графический кат изображены на Рис \ref{fig:sub1} (левый середина).
+Интегральный спектр E$_{T}$(4n), полученный как проекция рабочей области на вертикальную осьь изображена на  Рис \ref{fig:sub1} (правый верх).
+Затем, \textbf{мы предположили, что фоновые зелёные события распределены равномерно по рабочей области. 
+Получено, что плотность фоновых событий (после умножения на фактор пучка) равно 0.26 событий на единицу площади.
+Тогда, используя это предположение, проекция такого равномерного зелёного распределения на вертикальную ось дал, и факторизованное на интеграл пучка 6, дало одномер показанный на Рис \ref{fig:sub1} (правый середина). }
+После вычитания полученных гистограмм, было получено распределение изображённое в правом нижнем углу.
+
+
+Аналогичные процедуры были проделаны с выбором рабочей области для E$_{T}$(4n)>8 MeV.
+Результаты приведены на Рис \ref{fig:sub2}.
+При таком выборе, плотность фоновых событий на единицу площади равнялось 0.3 события на единицу площади, то есть на 20\% больше чем в первой итерации.
+
+\newpage
+
 	
 \end{document}
\ No newline at end of file

add1.tex

+\documentclass[12pt,a4paper]{article}
+
+\usepackage[utf8]{inputenc} % размер
+
+\usepackage[T2A]{fontenc} % указывает внутреннюю кодировку TeX
+
+\usepackage[ngerman,english]{babel}
+
+\usepackage{epsfig}
+\usepackage{xcolor}
+
+\usepackage[labelformat=simple]{subcaption}
+\usepackage{array,graphicx,caption}
+\usepackage{xcolor,color}		
+
+\begin{document}	
+	
+
+
+%-------------------------------------------------------------------------------
+\begin{figure}[t]
+	\begin{center}
+		\includegraphics[width=\textwidth]{figures/subract1}
+	\end{center}
+	%
+	\caption{
+		Top left: correlation E$_{T}$(4n) vs E$_{T}$($^7$H). Green color corresponds to the empty target. \\
+		Middle left: chosen area for analysis. Zoomed. \\ 
+		Top right: E$_{T}$(4n) obtained by projection of Middle left distribution to the left axis. \\
+		Middle right: E$_{T}$(4n) obtained by projection of the chosen area in suggestion of the homogeneously layout of the green events inside the area. Factorized by the beam factor 6. \\
+		Bottom right: E$_{T}$(4n) after subtraction.
+	}
+	%
+	\label{fig:sub1}
+\end{figure}
+%-------------------------------------------------------------------------------
+
+%-------------------------------------------------------------------------------
+\begin{figure}[t]
+	\begin{center}
+		\includegraphics[width=\textwidth]{figures/subract2}
+	\end{center}
+	%
+	\caption{
+		The chosen area was changed to choose the events with E$_{T}$($^7$H)>8 MeV only. The same logic was applied with the modified area.
+	}
+	%
+	\label{fig:sub2}
+\end{figure}
+%-------------------------------------------------------------------------------
+
+\newpage
+\thispagestyle{empty}
+
+Был сделан анализ фоновых событий, основываясь на двумерке E$_{T}$(4n) vs E$_{T}$($^7$H).
+То есть, на распределении E$_{T}$(4n) vs E$_{T}$($^7$H) Рис \ref{fig:sub1} (левый верх) выбиралась рабочая область.
+Отдельно события вошедшие в рабочую область и графический кат изображены на Рис \ref{fig:sub1} (левый середина).
+Интегральный спектр E$_{T}$(4n), полученный как проекция рабочей области на вертикальную осьь изображена на  Рис \ref{fig:sub1} (правый верх).
+Затем, \textbf{мы предположили, что фоновые зелёные события распределены равномерно по рабочей области. 
+Получено, что плотность фоновых событий (после умножения на фактор пучка) равно 0.26 событий на единицу площади.
+Тогда, используя это предположение, проекция такого равномерного зелёного распределения на вертикальную ось дал, и факторизованное на интеграл пучка 6, дало одномер показанный на Рис \ref{fig:sub1} (правый середина). }
+После вычитания полученных гистограмм, было получено распределение изображённое в правом нижнем углу.
+
+
+Аналогичные процедуры были проделаны с выбором рабочей области для E$_{T}$(4n)>8 MeV.
+Результаты приведены на Рис \ref{fig:sub2}.
+При таком выборе, плотность фоновых событий на единицу площади равнялось 0.3 события на единицу площади, то есть на 20\% больше чем в первой итерации.
+
+\newpage
+
+	
+\end{document}
\ No newline at end of file

all1.bib

@@ -9311,6 +9311,20 @@ T. Suzuki and M. Winkler and H. Wollnik and M. V. Zhukov,},
   year     = {2018},
 }
 
+@article{MOSZYNSKI1994226,
+	title = {Study of n-? discrimination with NE213 and BC501A liquid scintillators of different size},
+	journal = {Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment},
+	volume = {350},
+	number = {1},
+	pages = {226-234},
+	year = {1994},
+	issn = {0168-9002},
+	doi = {https://doi.org/10.1016/0168-9002(94)91169-X},
+	url = {https://www.sciencedirect.com/science/article/pii/016890029491169X},
+	author = {M. Moszy?ski and G.J. Costa and G. Guillaume and B. Heusch and A. Huck and S. Mouatassim},
+	abstract = {A comparative study of n-? discrimination by the digital charge comparison method was carried out for NE213 and BC501A scintillators of different size coupled to a 130 mm diameter XP4512B photomultiplier. Particularly, the scintillators of diameter 50 mm × 50 mm size are compared with those of 4 l volume (160 mm in diameter and 200 mm in depth). The figure of merit, M, of 3.81 measured with the diameter 50 mm × 50 mm BC501A scintillator at 1 MeV energy lost by recoil electrons, is much better than M of 2.05 as observed with the 4 l volume cell. This is the effect of the reduced photoelectron yield by about 50% determined for the 4 l volume scintillator. Moreover, the slowing down of the light pulse and multiscattering of neutrons have a further influence on the lowering of the M factor. The study of the M factor versus the initial delay and width of the gate set at the slow component showed that the early light of the slow component represented often by the intermediate component with the decay time constant of about 30 ns is of great importance for the n-? discrimination. Particularly, for the 4 l volume cells it is sufficient to limit the width of the gate at the slow component to about 300 ns. The comparison of the NE213 and BC501A scintillators showed that the BC501A scintillator exhibits a larger light yield evidently observed for the 4 l volume cell and thus giving a better n-? discrimination.}
+}
+
 @Article{Kanungo:2015,
   author    = {Kanungo, R. and Sanetullaev, A. and Tanaka, J. and Ishimoto, S. and Hagen, G. and Myo, T. and Suzuki, T. and Andreoiu, C. and Bender, P. and Chen, A. A. and Davids, B. and Fallis, J. and Fortin, J. P. and Galinski, N. and Gallant, A. T. and Garrett, P. E. and Hackman, G. and Hadinia, B. and Jansen, G. and Keefe, M. and Kr\"ucken, R. and Lighthall, J. and McNeice, E. and Miller, D. and Otsuka, T. and Purcell, J. and Randhawa, J. S. and Roger, T. and Rojas, A. and Savajols, H. and Shotter, A. and Tanihata, I. and Thompson, I. J. and Unsworth, C. and Voss, P. and Wang, Z.},
   title     = {Evidence of Soft Dipole Resonance in $^{11}\mathrm{Li}$ with Isoscalar Character},
@@ -10821,5 +10835,18 @@ telescopes using a CsI(Tl) crystal as residual energy detector.},
 	author = {H.B. Willard and J.K. Bair and C.M. Jones}
 }
 
+@article{Bezbakh:2023,
+	title = {Detector Array for the 7H Nucleus Multi-Neutron Decay Study},
+	journal = {Phys. Part. Nuclei Lett.},
+	volume = {20},
+	number = {4},
+	pages = {629?636},
+	year = {2023},
+	issn = {0031-9163},
+	doi = {https://doi.org/10.1016/0031-9163(64)90390-7},
+	url = {https://www.sciencedirect.com/science/article/pii/0031916364903907},
+	author = {A. A. Bezbakh, et al.}
+}
+
 
 @Comment{jabref-meta: databaseType:biblatex;}

tetra.tex

@@ -6,6 +6,7 @@
 
 \usepackage[ngerman,english]{babel}
 
+\usepackage{amssymb,epsfig,amsmath}
 \usepackage{epsfig}
 \usepackage{xcolor}
 
@@ -15,24 +16,32 @@
 
 \begin{document}	
 	
+\begin{center}
+
+
+\textbf{Search for the four-neutron quasi-resonance state populated in the $^2$H($^8$He,$^6$Li)4n reaction studied with the detection of the $^6$Li recoil nuclei.} \\
+
+\end{center}	
+	
 \section{Introduction}
 
 The search for the the multineutron systems is one of the most attractive fields of modern nuclear physics.
 The first suggestion about the stability of such systems was made in works \cite{Zeldovich:1960,Goldansky:1960}, but multiple experimental attempts of search for bound states of the neutron clusters (e.g. 2n in Ref.\ \cite{WILLARD1964339}, 3n in Ref.\ \cite{belozyorov:1988}, 4n in Ref.\ \cite{Marques_PhysRev:2002,Kisamori:2016}) were unsuccessful.
-Never the less, the issue of bound neutron nuclei existence is still addressed in the modern theoretical works, see Ref.\ \cite{Pieper:2003,Timofeyuk:2003b,Higgins:2021}.
-The recently published work \cite{Duer:2022} reported the observation of the resonance at 2.37\,MeV  with $\Gamma=1.75$\,MeV, which was interpreted as a tetraneutron state produced in a high-energy knockout reaction of alpha core from the $^8$He beam.
-The ensuing theoretical work \cite{Lazauskas:2023} provides the possible realistic explanation of observed phenomenon using the model based on a transition between initial and final state of four studied neutrons.
+Nevertheless, the issue of bound neutron nuclei existence is still addressed in the modern theoretical works, see Ref.\ \cite{Pieper:2003,Timofeyuk:2003b,Higgins:2021}.
+The recently published work \cite{Duer:2022} reported the observation of the resonance at 2.37\,MeV  with $\Gamma=1.75$\,MeV, which was interpreted as a tetraneutron state produced in a high-energy knockout of the alpha core from the $^8$He beam nuclei.
+The ensuing theoretical work \cite{Lazauskas:2023} provides the possible realistic explanation of the observed phenomenon using the model based on a transition between initial and final state of four studied neutrons.
 The published in Ref.\ \cite{Duer:2022} results are undoubtedly convincing but the used reaction of knockout of the alpha core from the $^8$He was studied only at very backward angles.
 Moreover, authors summarized that the obtained results are limited by the single approach of four-neutron system production and do not describe the correlation of the component neutrons.
-This work is dedicated to the results on the $^2$H($^8$He,$^6$Li) reaction studied at forward angles at ACCULINNA-2 fragment separator. 
+This work is dedicated to the results on the $^2$H($^8$He,$^6$Li) reaction at the ACCULINNA-2 fragment separator in the experiment dedicated to the study of the $^7$H resonant states populated in the $^2$H($^8$He,$^7$H) reaction. 
 
 
 \section{Experiment}
 
 
 ACCULINNA-2 facility, FLNR, JINR, produced the 26\,AMeV $^{8}$He beam with intensity $\approx10^{5}$\,pps.
-This beam was focused on the cryogenic gaseous deuterium 27\,K target with a temperature of 27\,K equipped with stainless steel and mylar windows. 
-Initially, 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.
+This beam was focused on the cryogenic gaseous deuterium 27\,K target with a temperature of 27\,K equipped with the stainless-steel and mylar windows.
+The target thickness was 3.7$\times$10$^{20}$ cm$^{-2}$. 
+Initially, the experiment was dedicated to the $^{7}$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 the further multibody decay of the produced unbound system.
 The employed detector system is widely described in Ref.\ \cite{Muzalevskii:2021}.
 
 The beam particles were identified by two plastic scintillators, which allowed to measure the energy of the projectile from its time-of-flight (ToF). 
@@ -41,50 +50,106 @@ The beam particles were identified by two plastic scintillators, which allowed t
 The motion vector of were reconstructed by two pairs of multi-wire proportional chambers. 
 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.
-%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 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=0.51\linewidth]{figures/deE_side} 
 		&
-		\includegraphics[width=0.48\linewidth]{figures/tof} \\
+		\includegraphics[width=0.49\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.
+		(a) Identification of $^{6}$Li recoil nuclei by $\Delta E$-$E$ method in side telescopes.
+		(b) The ToF distribution obtained for the stilbene-array signals triggered by the $^6$Li recoils.
+		The set of three peaks below ToF = 1-ns corresponds to the gamma rays produced in the diaphragm installed 20 cm upstream the target plane, target frame, and CsI(Tl) array which was in use in experiments \cite{Bezbakh:2018}.
+		The green and red-line histograms are formed by the events, identified as gamma/neutron by the dE-TAC method.
 	}
 	\label{fig:ND_id}
 \end{figure}
 %-------------------------------------------------------------------------------
 
-Tetranuetron was reconstructed from the recoil $^6$Li as a missing component in $^2$H($^8$He,$^6$Li) reaction.
+The detection of the charged reaction products was realized by the $\Delta E$-$E-E$ telescopes.
+The recoil $^6$Li nuclei, appearing in the $^2$H($^8$He,$^6$Li) reaction hit the array of four identical $\Delta E$-$E-E$ telescopes.
+The telescope array was located 179 mm downstream the target.
+Each telescope consisted of three layers of silicon strip detectors (SSDs).
+The 20-$\mu$m-thick SSD with a sensitive area of 50$\times$50 mm$^2$ was divided into 16 strips, the second and the third layers were created by the two identical 1 mm-thick SSDs (60$\times$60 mm$^2$ with 16 strips). 
+The $^6$Li recoiles emitted from the deuterium gas target in the $^2$H($^8$He,$^6$Li) reaction in a range 6-24 degrees in the laboratory system were detected by this telescope array with probability rising from about 10\% obtained at the small $\theta_{\text{lab}}$ to about 50\% at the larger angles. 
+The signals obtained from these telescope detectors allowed to identify $^6$Li with clear separation from other registered lithium isotopes.
+Shown in Fig.\,\ref{fig:exp-deltaee-3he} is the typical identification plot obtained for Z = 1, 2, and 3 recoil nuclei in one of the four side silicon telescopes.
+%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.
+
+
+
+%-------------------------------------------------------------------------------
+%\begin{figure}
+%	\begin{center}
+%		\includegraphics[width=0.49\textwidth]{figures/deE_side}
+%	\end{center}
+	%
+%	\caption{
+%		Identification of $^{6}$Li recoil nuclei by $\Delta E$-$E$ method in side telescopes.
+%	}
+	%
+%	\label{fig:exp-deltaee-3he}
+%\end{figure}
+%-------------------------------------------------------------------------------
+
+The group of four neutrons remaining free as a result of the $\alpha$-core removal from the $^8$He projectile.
+Neutron were detected by the time-of-flight (ToF) stilbene modules \cite{Bezbakh:2018}%, which provides clear neutron-gamma separation and allow to calculate the particle energy from its ToF.
+The setup included 48 stilbene scintilator crystals placed on a 0.7$\times$1.1 mm$^2$ area moved 2\,m back from the target at zero angle to the $^8$He beam axis. 
+The distance between the 50-mm thick and 80\,mm diameter stilbene crystals was approximately
+12\,cm which resulted in a $\sim$30\% probability for neutrons to hit a stilbene detector. 
+The stilbene array provided 4.5\% energy resolution and the single neutron registration efficiency
+of $\approx$15\%. 
+The probability of a neutron registration in coincidence with the $^{6}$Li recoil  was around 10\%, taking into account that four neutrons are flying forward, towards the stilbene array, in each case when this recoil is detected.
+
+
+
+%The neutron identification was realized 
+
+\section{Results}
+
+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.
+The neutron-gamma separation was made by means of the Pulse Shape Discrimination (PSD) \cite{MOSZYNSKI1994226}. 
+The selection each of them on the ToF distribution, see Fig.\,\ref{fig:tof} leads to the suggestion that some gamma-type signals correspond to neutron-like ToF.
+These gammas are produced by the interaction of the neutrons with the stilbene housing and should be considered as neutron events.
+
+
+%-------------------------------------------------------------------------------
+%\begin{figure}
+%	\begin{center}
+%		\includegraphics[width=0.49\textwidth]{figures/tof}
+%	\end{center}
+	%
+%	\caption{
+%		The ToF distribution obtained for the stilbene-array signals triggered by the $^6$Li recoils.
+%		The set of three peaks below ToF = 1-ns corresponds to the gamma rays produced in the %diaphragm installed 20 cm upstream the target plane, target frame, and CsI(Tl) array which was in use in experiments \cite{Bezbakh:2018}.
+%		The green and red-line histograms are formed by the events, identified as gamma/neutron by the dE-TAC method.
+%	}
+	%
+%	\label{fig:tof}
+%\end{figure}
+%-------------------------------------------------------------------------------
+
+Tetranuetron was reconstructed from the recoil $^6$Li as a missing component in the $^2$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.
+%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).
+The data points of these events are presented in Fig.\ \ref{fig:mm_4n} (a), where the neutron kinetic energy $E_n$(4n c.m.s.) in the 4n center-of-mass frame is compared with the reconstructed missing-mass (MM) energy $E_T$ of the 4n group. .
+The fact that the magority of these events (108 data points out of 136) 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).
+
+The MM spectrum of 4n group, occuring in the $^2$H($^8$He,$^6$Li)4n reaction, was reconstracted from the measured $^6$Li recoil energy and emission angle, taking the 108 events with the data points lying below the kinematical border $E_{n} < $3/4$E_T$(4n) reconstructed after kinematic selection.
+This spectrum is shown in Fig.\ \ref{fig:mm_4n} (b).
+Obviously, the obtained spectrum shape can not be described just as a contribution of the 4-body phase space volume, see the orange dotted curve in Fig.\ \ref{fig:mm_4n} (b).
+Apparently, one can assume the presence of some resonance-like state (or states) lying at 3-4\,MeV above the 4n decay threshold.
+It is notable that the observed peak energy is consistent with the reported in Ref.\ \cite{Duer:2022}  observation of the correlated free four-neutron system.
+%Its important evidence for the tetraneutron resonance at low energies above the 4n decay threshold obtained at forward angles in the reaction of alpha core knockout from the $^8$He beam.
 
 %-------------------------------------------------------------------------------
 \begin{figure}
@@ -105,18 +170,16 @@ The missing mass (MM) spectrum of 4n reconstructed after kinematic selection is
 \end{figure}
 %-------------------------------------------------------------------------------
 
-Obviously, this spectrum shape can not be described just as a contribution of the 4-body phase space volume, see the orange dotted curve in Fig.\ \ref{fig:mm_4n} (b), indicating the presence of some resonance states of 4n lying at 3-4\,MeV above the 4n decay threshold.
-Its important to notice that the observed peak is consistent with the reported in Ref.\ \cite{Duer:2022} and previous Ref.\ \cite{Kisamori:2016} results.
-Its important evidence for the tetraneutron resonance at low energies above the 4n decay threshold obtained at forward angles in the reaction of alpha core knockout from the $^8$He beam.
-
 
 \section{Conclusion}
 
-The $^2$H($^8$He,$^6$Li)4n reaction was studied at forward angles.
-The observed peak at 3-4 MeV above the 4n threshold is in agreement with Ref.\ \cite{Duer:2022,Kisamori:2016}.
-The obtained results are pushing the investigation of the neutron clusters.
-The configuration of the detector setup specifically for such reaction and improved neutron detection efficiency is demanded in the future experiments.
-The latter will not also increase statistics but also will allow to study neutron cluster decays in full kinematics reconstructed by the invariant mass methods. 
+The $^2$H($^8$He,$^6$Li)4n reaction was studied at the center-of-mass forward angles  $\theta_{\text{cm}}$ = 10-50 degrees.
+The observed peak at 3-4 MeV above the 4n threshold is in agreement with the correlated free four-neutron system observation made in Ref.\ \cite{Duer:2022}.
+Cross-section value $\sim$10$^{-28}$ cm$^2$/sr is estimated for the reaction resulting in the population of this peak.
+%The obtained results are pushing the investigation of the neutron clusters.
+The choice of the detector setup made specifically for the study of such reaction and is demanded in the future experiments.
+In particular, the neutron detection efficiency will be increased drastically by the use of the detector array presented in Ref.\ \cite{Bezbakh:2023}.
+The latter will increase statistics and will allow to study neutron cluster decays in full kinematics reconstructed by the invariant mass methods. 
 
 
 \section{Acknowledgement}