scholarly journals Measurement and simulation of the new liquid organic scintillator response to fast neutrons

2021 ◽  
Vol 253 ◽  
pp. 11006
Author(s):  
Jaroslav Jánský ◽  
Jiřĺ Janda ◽  
Zdeněk Matěj ◽  
Filip Mravec ◽  
Michal Košťál ◽  
...  
Keyword(s):  
Functional Dependence ◽  
Neutron Radiation ◽  
Dissipated Energy ◽  
Fast Neutrons ◽  
Function Evaluation ◽  
Neutron Spectrometry ◽  
Carbon Ion ◽  
Organic Scintillator ◽  
Organic Scintillators ◽  
Liquid Organic Scintillator

Liquid organic scintillators are important devices for measurements of neutron radiation. This work aims to develop and optimize the composition of liquid organic scintillators so it can be used for fast neutron spectrometry. As the neutron radiation is usually accompanied with γ ray radiation, it is important to have quality γ/n discrimination. The new cocktail for house made liquid organic scintillator is prepared and studied with intention of being able to separate gamma and neutron for neutron energies above 0.5 MeV while keeping lower constraints on practical use (e.g., sealing because of oxygen) than commercial liquid scintillators. In preceding work the composition of liquid scintillators was optimized. Two twocomponent scintillators were selected for further studies. Solvent DIPN (Di-iso-propyl-naphthalene Mixed Isomers) is selected for both. First is mixed with luminophore PYR (1-Phenyl-3-(2,4,6-trimethyl-phenyl)-2-pyrazoline) of concentration 5 g/l. Second is mixed with luminophore THIO (2,5-Bis(5-tert-butyl-benzoxazol-2-yl)thiophene) of concentration 5 g/l. In this work the response of scintillator to monoenergetic beam of neutrons was measured for multiple neutron energies at PTB in Braunschweig. The two parameter spectrometric system NGA-01 is used to analyze the energy and discrimination characteristics. 137 Cs and 60 Co are used as radiation sources for calibration with pure γ rays. Then the response of scintillator for same neutron energies was simulated using GEANT4. The dissipated energy in the scintillator in response to monoenergetic neutrons is obtained. Both, measured and simulated responses are compared. Functional dependence for yield of recoiled products is estimated. It is seen that main recoil product hydrogen proton is well observed in both. From the edge of proton response one can assume the yield for given neutron energy. The recoiled carbon ion (from elastic collision) is on the other side difficult to observe in measured results but clearly seen in dissipated energy plots. It suggests that yield of carbon ion is very small relatively to proton yield. These results will serve as basis for response function evaluation of scintillator which is necessary for evaluation of unknown neutron spectra from measurements with scintillator.

Energieübertragung in verschiedenen flüssigen organischen Szintillatorsystemen / Energy Transfer in Some Liquid Organic Scintillator Systems

1977 ◽  
Vol 32 (12) ◽  
pp. 1368-1373
Author(s):  
A. Kawski ◽  
T. Waśniewski
Keyword(s):  
Energy Transfer ◽  
Gamma Radiation ◽  
Fluorescence Intensity ◽  
High Energy ◽  
Intensity Maximum ◽  
Organic Scintillator ◽  
Similar Dependence ◽  
Energy Gamma ◽  
Benzene Toluene ◽  
Liquid Organic Scintillator

Abstract Energy Transfer in Some Liquid Organic Scintillator Systems Experimental results of fluorescence induced by high energy (gamma radiation) excitation in solutions of various solutes (isoeugenole, methylisoeugenole, 2-phenylindole, N-phenyl-2-naphthyl-amine, acenaphthene, 2,6-dimethylnaphthalene and 2,5-diphenyloxazole) in various solvents (benzene, toluene, xylene and xylene/n-butanol) are compared with the Bothe equation. Good agree­ ment was found with the Bothe equation which takes into account the fluorescence of solute and solvent. A linear dependence of the fluorescence intensity maximum Jmax on P/(R-K) for different solutes in a given solvent was found. A similar dependence was also found for 2,5-diphenyloxazole in xylene/n-butanol mixtures. An interpretation of the observed effects is given.

scholarly journals Separate detection of ionizing radiation with different specific energy losses by organic heterostructured scintillators

2019 ◽  
Keyword(s):  
Ionizing Radiation ◽  
Energy Loss ◽  
Single Crystals ◽  
Specific Energy ◽  
Slow Component ◽  
Alpha Particles ◽  
Fast Neutrons ◽  
Annihilation Process ◽  
Organic Scintillators ◽  
Hot Pressing Sintering

Molecular organic scintillation materials are the most effective objects for creating systems that detect the kinds of radiation, that the most harmful to humans (alpha particles, fast neutrons, etc.). In addition, organic crystals and liquids are capable to separate these types of radiation from photons of background gamma radiation. In these scintillators, ionizing radiation generates two types of luminescent response– prompt and delayed radioluminescence Ionizing radiation with a high specific energy loss dE/dx, i.e. energy loss E per unit path length x, generate a scintillation pulse in these media with a high proportion of the slow component. Recently, new types of scintillators have been developed, namely, heterogeneous organic scintillators containing single-crystal scintillation grains that can be combined by hot pressing sintering (polycrystals or Van der Waals ceramics) or can be incorporated into a transparent gel composition (composite scintillators). the ability of heterogeneous organic scintillators to separate signals from radiation with different dE/dx and the physical basis of this process in heterogeneous scintillation materials remain one of the urgent, unexplored problems. This work presents the results of the study of the form of scintillation pulse shapes for the samples of organic single crystals, polycrystals and compositional scintillators based on stilbene in comparison with the same results obtained for p-terphenyl and anthracene for various types of ionizing radiation excitations. The peculiarities of the influence of the triplet-triplet annihilation process on the formation of a slow component of the radioluminescence pulse in these systems have being studied. We found that the ability of new types of organic heterogeneous materials (polycrystals and composite scintillators) to the separate registration of ionizing radiation in the shape of the scintillation pulse is close to the corresponding values that characterize this ability of structurally perfect single crystals.

scholarly journals Cинтез и испытания 1 m-=SUP=-3-=/SUP=- жидкого сцинтиллятора на основе линейного алкилбензола

2019 ◽  
Vol 45 (1) ◽  
pp. 54
Author(s):  
Д.С. Кузнецов ◽  
Е.А. Литвинович ◽  
А.Е. Мурченко ◽  
Б.А. Обиняков ◽  
А.Ю. Оралбаев ◽  
...  
Keyword(s):  
Light Yield ◽  
Observation Time ◽  
Kurchatov Institute ◽  
Linear Alkylbenzene ◽  
Organic Scintillator ◽  
Long Term Stability ◽  
Antineutrino Detector ◽  
Liquid Organic Scintillator ◽  
Systemic Degradation

AbstractThe stability of a liquid organic scintillator based on linear alkylbenzene in a volume of 1 m^3 was measured. The measurements were performed using an iDREAM reactor antineutrino detector at the National Research Center Kurchatov Institute. No systemic degradation of the scintillator light yield within an observation time of 225 days was observed. These long-term stability measurements of a large-volume liquid organic scintillator based on linear alkylbenzene are the first in Russia.

scholarly journals FAST ROSSI-ALPHA MEASUREMENTS OF PLUTONIUM USING ORGANIC SCINTILLATORS

2021 ◽  
Vol 247 ◽  
pp. 09025
Author(s):  
M.Y. Hua ◽  
C.A. Bravo ◽  
A.T. MacDonald ◽  
J.D. Hutchinson ◽  
G.E. McKenzie ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Confidence Intervals ◽  
Decay Constant ◽  
Detection System ◽  
Prompt Neutron ◽  
Neutron Decay ◽  
Organic Scintillator ◽  
Slowing Down ◽  
Organic Scintillators

In this work, Rossi-alpha measurements were simultaneously performed with a 3He-based detection system and an organic scintillator-based detection system. The assembly is 15 kg of plutonium (93 wt% 239Pu) reflected by copper and moderated by lead. The goal of Rossi-alpha measurements is to estimate the prompt neutron decay constant, alpha. Simulations estimate keff = 0:624 and α = 52:3 ± 2:5 ns for the measured assembly. The organic scintillator system estimated α = 47:4 ± 2:0 ns, having a 9.37% error (though the 1.09 standard deviation confidence intervals overlapped). The 3He system estimated α = 37 μs. The known slowing down time of the 3He system is 35-40 μs, which means the slowing down time dominates and obscures the prompt neutron decay constant. Subsequently, the organic scintillator system should be used for assemblies with alpha much less than 35 μs.

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