Scintillation neutron detector on the basis of boron-containing plastics
Main parameters are presented for plastic scintillators containing boron. These scintillators were obtained by the block polymerization method of polystyrene with luminescent dopants and allyldodecaborane. Sample dimensions: diameter 25 mm, height 25 mm. Parameters studied included light output, s...
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Національний науковий центр «Харківський фізико-технічний інститут» НАН України
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irk-123456789-793812015-04-01T03:02:15Z Scintillation neutron detector on the basis of boron-containing plastics Ryzhikov, V.D. Desenko, S.M. Kopina, I.V. Afanasiadi, L.Sh. Chernikov, V.V. Onyshchenko, G.M. Детекторы и детектирование ядерных излучений Main parameters are presented for plastic scintillators containing boron. These scintillators were obtained by the block polymerization method of polystyrene with luminescent dopants and allyldodecaborane. Sample dimensions: diameter 25 mm, height 25 mm. Parameters studied included light output, sensitivity to neutrons and time characteristics. У роботі представлені основні параметри пластмасових сцинтиляторів, які містять бор. Ці сцинтилятори одержані за допомогою методу блочної полімеризації полістиролу з домішками, що випромінюють люмінесценцію та алилдодекабораном. Розміри зразків: Ø25х25 мм. Досліджені світловий вихід, чутливість до нейтронів та компоненти висвічування. В работе представлены основные параметры пластмассовых сцинтилляторов, содержащих бор. Эти сцинтилляторы получены методом блочной полимеризации полистирола с люминесцирующими добавками и аллилдодекабораном. Размеры образцов: диаметр 25 мм и высота 25 мм. Исследованы световой выход, чувствительность к нейтронам и времен- ные характеристики. 2004 Article Scintillation neutron detector on the basis of boron-containing plastics / V.D. Ryzhikov, S.M. Desenko, I.V. Kopina, L.Sh. Afanasiadi, V.V. Chernikov, G.M. Onyshchenko // Вопросы атомной науки и техники. — 2004. — № 2. — С. 169-170. — Бібліогр.: 6 назв. — англ. 1562-6016 PACS: 29.40.Mc http://dspace.nbuv.gov.ua/handle/123456789/79381 en Вопросы атомной науки и техники Національний науковий центр «Харківський фізико-технічний інститут» НАН України |
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Digital Library of Periodicals of National Academy of Sciences of Ukraine |
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Детекторы и детектирование ядерных излучений Детекторы и детектирование ядерных излучений |
| spellingShingle |
Детекторы и детектирование ядерных излучений Детекторы и детектирование ядерных излучений Ryzhikov, V.D. Desenko, S.M. Kopina, I.V. Afanasiadi, L.Sh. Chernikov, V.V. Onyshchenko, G.M. Scintillation neutron detector on the basis of boron-containing plastics Вопросы атомной науки и техники |
| description |
Main parameters are presented for plastic scintillators containing boron. These scintillators were obtained by the block
polymerization method of polystyrene with luminescent dopants and allyldodecaborane. Sample dimensions: diameter
25 mm, height 25 mm. Parameters studied included light output, sensitivity to neutrons and time characteristics. |
| format |
Article |
| author |
Ryzhikov, V.D. Desenko, S.M. Kopina, I.V. Afanasiadi, L.Sh. Chernikov, V.V. Onyshchenko, G.M. |
| author_facet |
Ryzhikov, V.D. Desenko, S.M. Kopina, I.V. Afanasiadi, L.Sh. Chernikov, V.V. Onyshchenko, G.M. |
| author_sort |
Ryzhikov, V.D. |
| title |
Scintillation neutron detector on the basis of boron-containing plastics |
| title_short |
Scintillation neutron detector on the basis of boron-containing plastics |
| title_full |
Scintillation neutron detector on the basis of boron-containing plastics |
| title_fullStr |
Scintillation neutron detector on the basis of boron-containing plastics |
| title_full_unstemmed |
Scintillation neutron detector on the basis of boron-containing plastics |
| title_sort |
scintillation neutron detector on the basis of boron-containing plastics |
| publisher |
Національний науковий центр «Харківський фізико-технічний інститут» НАН України |
| publishDate |
2004 |
| topic_facet |
Детекторы и детектирование ядерных излучений |
| url |
http://dspace.nbuv.gov.ua/handle/123456789/79381 |
| citation_txt |
Scintillation neutron detector on the basis of boron-containing plastics / V.D. Ryzhikov, S.M. Desenko, I.V. Kopina, L.Sh. Afanasiadi, V.V. Chernikov, G.M. Onyshchenko // Вопросы атомной науки и техники. — 2004. — № 2. — С. 169-170. — Бібліогр.: 6 назв. — англ. |
| series |
Вопросы атомной науки и техники |
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2025-07-06T03:26:56Z |
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2025-07-06T03:26:56Z |
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| fulltext |
SCINTILLATION NEUTRON DETECTOR
ON THE BASIS OF BORON-CONTAINING PLASTICS
V.D.Ryzhikov, S.M.Desenko, I.V.Kopina, L.Sh.Afanasiadi, V.V.Chernikov,
G.M.Onyshchenko
STC RI, STC “Institute for Single Crystals”, 60 Lenin ave., Kharkiv, 61001, Ukraine
E-mail: stcri@isc.kharkov.com
Main parameters are presented for plastic scintillators containing boron. These scintillators were obtained by the block
polymerization method of polystyrene with luminescent dopants and allyldodecaborane. Sample dimensions: diameter
25 mm, height 25 mm. Parameters studied included light output, sensitivity to neutrons and time characteristics.
PACS: 29.40.Mc
1. INTRODUCTION
Plastic scintillators containing 10В show many ad-
vantages over other neutron detectors, such as high de-
tection efficiency and low intrinsic background, as well
as high radiation stability.
Thermal neutrons are detected by such scintillators
mainly as a result of exothermal reaction 10В(n,αγ)7Li
(interaction cross-section δ=3840 barn):
7Li+γ (Eγ=0.480 МeV)
In 93.7% of cases (in the neutron energy range from
thermal to 0.2 МeV) 7Li is formed in the excited state.
In transition from the excited to the basic state, the lithi-
um nucleus (Т1/2=67.3·10-15 s) emits a gamma-quantum
of energy Еγ=0.480 МeV.
Detection of fast neutrons is possible by the recoil
protons, as well by the reaction:
11 1 8 4
5 0 3 2B n Li He+ → +
β¯, 0.847 s 8
4
2Be α→ , 10-16 s
This reaction is endothermic, its threshold is
6.63 МeV, and the cross-section is 4·10-26 сm2. 8Li nucleus
with Т1/2=0.847 s is transformed into two α-particles of 1.5
МeV energy each, and one β-частицу of energy 13 МeV.
The light yield in a plastic scintillator due to capture
of thermal neutrons from α-particles and 7Li nuclei is
equivalent to the yield from γ-quanta or electrons of en-
ergies from 65 to 480 keV.
At such lifetime, the detection probability of γ-quanta
with Еγ =480 keV is rather high, which can noticeably af-
fect the pulse discrimination by their shape. However,
equipment of new generation, with time resolution of tens
of picoseconds, allows us to approach the solution of this
problem. The light yield resulting of thermal neutron cap-
ture from α-particles is equivalent to the yield from
γ - quanta or electrons with energies from 65 to 160 keV.
2. EXPERIMENTAL AND RESULTS
In several papers, studies were reported on a possi-
bility to use different boron-organic compounds in plas-
tic scintillators (see, e.g., [1]). However, little attention
has been paid to the problem of creation of efficient fast
boron-containing plastic scintillators with maximum
possible boron content and good transparence at the
emission spectrum maximum for detection of neutrons
with energies up to 10 MeV.
Attempts were made of introducing various boron-
organic compounds into liquid scintillators [1], though
efficient light output and a possibility of discrimination
over pulse shape were shown only for trimethylborate.
Boron content in trimethylborate was 9.7%. As detec-
tion efficiency of thermal neutrons depends of the intro-
duced boron content, this compound has to be intro-
duced into liquid scintillators in high concentrations (up
to 50 mass %), which affects the scintillation properties
of the material. Moreover, for trimethylborate, as well
as for other boric acid esters, a problem is its low stabil-
ity with respect to moisture, leading to hydrolysis, with
boric acid (non-soluble in weakly polar organic media)
being one of its products:
where R is an alkyl group. Formation of the precipitate
of this compound leads to property degradation with
time of the liquid scintillator; therefore, boric acid esters
are hardly suitable for their use in plastic scintillators.
For neutron detection, we have developed specially
made compositions of types Т-1 и Т-2 [2], which con-
tain boron compounds enriched in B10
5 isotope (its
concentration in the natural boron is ∼ 20%), lithium
compounds enriched in Li6
3 , as well as ZnS(Ag). In
most cases, boron and lithium are used in the form of
oxides or fluorides. Introduction of the luminescent
composition into the polymer was carried out either by
the method of hot pressure compaction of the mixture of
the composition and polymer dissolved in the monomer,
or by polymerization. Polystyrene or polymethyl-
metacrylate was used as the polymeric basis.
The scintillators obtained by compaction in the form
of pellets up to 10 mm in diameter were of milk-white
color and low optical transparence. Using thermal poly-
merization, we succeeded in obtaining scintillators with
relatively uniform distribution of the luminescent com-
position over its volume. However, the scintillator thick-
ness should not be higher than 5 mm, as the optical
transparence noticeably decreased with thicker samples.
In addition, during the polymerization process it is very
difficult to keep the luminescent composition grains larger
than 150 μm in suspended state over all the polymethyl-
___________________________________________________________
PROBLEMS OF ATOMIC SIENCE AND TECHNOLOGY. 2004. № 2.
Series: Nuclear Physics Investigations (43), p.169-170. 169
10 1
5 0B n+ →
7
7
(1.015 MeV) ( 1.777 MeV) ( 2.792 MeV)
*(0.840 MeV) ( 1.470 MeV) ( 2.310 MeV)
p
p
Li E Q
Li E Q
α
α
α
α
+ = =
+ = =
B(OR)3 + 3 H2O → B(OH)3 + 3 ROH
↓
mailto:stcri@isc.kharkov.com
metacrylate volume, because the density of polymethyl-
metacrylate is higher than that of luminescent composition.
As a result of mechanical treatment of the scintillator
piece (cutting, grinding, polishing), luminescent composi-
tion grains were partially coming out to the polymer sur-
face. These grains being hygroscopic (and, consequently,
tending to change their chemical composition), it was not
possible to obtain scintillators with uniform counting
characteristics. Thus, reliability of thermal neutron mea-
surements using such scintillators was not sufficiently
high.
The presence of non-soluble (suspended) fraction of
the luminescent composition decreases the light yield
and increases light absorption in the bulk scintillator.
Accounting for this, the detector should combine detec-
tion of fast neutrons over recoil protons (i.e., function of
a conventional plastic scintillator) and the presence in it
of boron compounds that cause the above-described re-
action. The role of plastic scintillator included also de-
tection of the formed heavy charged particles. This im-
plies the requirement for homogeneity and high trans-
parence of the whole scintillation system.
Consequently, the other way to obtain the required
solid-state detector was to introduce a boron-containing
compound – isopropenylcarborane – into a plastic scin-
tillator containing luminescent dopants.
This substance has high stability characteristics with
respect to various external factors, it is well soluble in
non-polar and weakly polar organic media, displays no
absorption bands in the visible spectral range, and, due
to the presence of isopropenyl group, can be co-poly-
merized with vinyl monomers of aromatic series
(styrene, vyniltoluene, vynilxylene, etc.).
However, isopropenylcarborane could be introduced
in quantities not more than 5 mass %. Neutron detection
efficiency of such scintillator is rather low [3]. There are
also reports on the use of o-carborane in plastic scintilla-
tors [4], which contains somewhat larger quantity of
boron (67 mass %) as compared with its isopropenyl
derivative (49%). This substance was introduced into
polystyrene with mass fraction of boron up to 5%.
Also known are boron-containing plastic scintillators
where decaborane В10Н14 was used as boron-containing
compound [4]. However, such plastic scintillators, due to
limited solubility of the introduced boron-organic com-
pound, contained not more than 15 mass % of В10Н14 .
This feature does not allow increasing absorption of the
ionizing radiation, thus improving detection efficiency of
thermal neutrons. Moreover, decaborane В10Н14 is a toxic
compound, easily oxidized in air, which substantially lim-
its its possible use in production of plastic scintillators.
It seemed interesting for us to study plastic scintilla-
tors with yet another substance, which has not been used
in plastic scintillator production - allyldecaborane:
(СН 2 = СНСН2)В12 Н12
Due to its high solubility in the monomer, it can be in-
troduced in amounts of up to 20 mass % of boron.
From the obtained pieces, we prepared samples
25 mm in diameter and 25 mm high. The light output of
such detectors with respect to anthracene was 42%, ef-
fective light attenuation length is increased by 1.4 times,
leading to substantial (by about 1.7 times) increase in
detection efficiency of thermal neutrons. The α/β-ratio
remains within the limits of 0.05-0.07.
3. CONCLUSIONS
Thus, high optical transparence allows fabrication of
scintillators of different sizes and complex shapes, as
well as combined detectors on the basis of gadolinium
silicate and plastics. Detectors of small sizes allowed
full realization of these advantages for pulse discrimina-
tion by shape and ensuring fast time characteristics.
REFERENCES
1. G.P.Anisimova, L.S.Danelyan, A.F.Zhigach e.a.
Plastic boron-containing scintillators. // Pribory i
tekhnika eksperimenta. 1969, No.1, p.49-51.
2. B.M.Kolesov, A.K.Ovchinnikov, I.M.Khaikovich
e.a. Scintillation counter ZnS+B – a threshold de-
tector of pulse flux of fast neutrons // Pribory i
tekhnika eksperiment. 1973, No.4, p.82-84.
3. V.B.Brudanin, O.I.Kochetov, I.B.Nemchenok e.a.
Boron-containing plastic scintillator on the basis of
polystyrene // Izvestiya Akademii Nauk. Ser. Fiz.
2001, v.65, No.1, p.60-65.
4. N.V.Kirpichnikov. Scintillation counter of slow
neutrons, non-sensitive to gamma-radiation .// Nu-
cleon Electronics. v.1, Vienna, 1962, с.139-141.
5. O.A.Gunder, I.V.Kopina, L.Sh.Afanasiadi. Boron-
containing plastic scintillator. – Abstracts of Inter-
State Conference “Scintillators-93”, Sept.27-30.
Kharkov, 1993, part 1, p.62.
6. Patent of Ukraine No. 5672.
СЦИНТИЛЛЯЦИОННЫЙ НЕЙТРОННЫЙ ДЕТЕКТОР НА ОСНОВЕ БОРО-СОДЕРЖАЩИХ
ПЛАСТМАССОВЫХ СЦИНТИЛЛЯТОРОВ
В.Д.Рыжиков, С.М.Десенко, И.В.Копина, Л.Ш.Афанасиади, В.В.Черников, Г.М.Онищенко
В работе представлены основные параметры пластмассовых сцинтилляторов, содержащих бор. Эти сцинтилляторы
получены методом блочной полимеризации полистирола с люминесцирующими добавками и аллилдодекабораном. Раз-
меры образцов: диаметр 25 мм и высота 25 мм. Исследованы световой выход, чувствительность к нейтронам и времен-
ные характеристики.
СЦИНТИЛЯЦІЙНИЙ НЕЙТРОННИЙ ДЕТЕКТОР НА ОСНОВІ
ПЛАСТМАСОВИХ СЦИНТИЛЯТОРІВ, ЯКІ МІСТЯТЬ БОР
В.Д.Рижиков, С.М.Десенко, И.В.Копіна, Л.Ш. Афанасіаді, В.В.Черніков, Г.М. Онищенко
У роботі представлені основні параметри пластмасових сцинтиляторів, які містять бор. Ці сцинтилятори одержані за
допомогою методу блочної полімеризації полістиролу з домішками, що випромінюють люмінесценцію та алилдодекабо-
раном. Розміри зразків: Ø25х25 мм. Досліджені світловий вихід, чутливість до нейтронів та компоненти висвічування.
170
References
СЦИНТИЛЛЯЦИОННЫЙ НЕЙТРОННЫЙ ДЕТЕКТОР НА ОСНОВЕ БОРО-СОДЕРЖАЩИХ
ПЛАСТМАССОВЫХ СЦИНТИЛЛЯТОРОВ
СЦИНТИЛЯЦІЙНИЙ НЕЙТРОННИЙ ДЕТЕКТОР НА ОСНОВІ
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