On the multipurpose use of a portable neutron source
The possibility of creating a multipurpose complex for generating a reference field of thermal neutrons based on a portable neutron source (PNS) is considered. It has been shown that our method can be used to detect fissile materials without determining their isotopic composition during an inspectio...
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Національний науковий центр «Харківський фізико-технічний інститут» НАН України
2020
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| Назва видання: | Вопросы атомной науки и техники |
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| Цитувати: | On the multipurpose use of a portable neutron source / E.L. Kuplennikov, A.N. Vodin, O.S. Deiev, S.S. Kandybei, S.N. Olejnik, A.F. Stoyanov, I.S. Timchenko, V.S. Trubnikov, V.A. Tsymbal // Problems of atomic science and tecnology. — 2020. — № 3. — С. 163-167. — Бібліогр.: 20 назв. — англ. |
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nasplib_isofts_kiev_ua-123456789-1945482025-02-23T17:17:16Z On the multipurpose use of a portable neutron source Про багатоцільове використання портативного джерела нейтронів О многоцелевом использовании портативного источника нейтронов Kuplennikov, E.L. Vodin, A.N. Deiev, O.S. Kandybei, S.S. Olejnik, S.N. Stoyanov, A.F. Timchenko, I.S. Trubnikov, V.S. Tsymbal, V.A. Application of nuclear methods The possibility of creating a multipurpose complex for generating a reference field of thermal neutrons based on a portable neutron source (PNS) is considered. It has been shown that our method can be used to detect fissile materials without determining their isotopic composition during an inspection of the hand luggage of passengers, mail,etc. The PNS multipurpose complex will allow to indirectly indicating the possible presence of chemical explosives in the test samples, as well as cadmium and boron, which possibly hide fissile elements from detection. The paper gives recommendations on the use of the most effective instruments and equipment. Розглянута можливість створення багатофункціонального комплексу для генерування опорного поля теплових нейтронів на базі портативного джерела нейтронів (ПДН). Показано, що розробка може бути використана для виявлення матеріалів, що діляться, без визначення їх ізотопного складу при огляді ручної поклажі пасажирів, поштових відправлень і т. п. Крім того, комплекс ПДН дозволить побічно вказати на можливу присутність у досліджуваному об’ємі хімічної вибухової речовини, а також кадмію і бору, які можливо приховують елементи, що діляться, від виявлення. Дані рекомендації по застосуванню найбільш ефективних приладів та обладнання. Рассмотрена возможность создания многофункционального комплекса для генерации опорного поля тепловых нейтронов на основе портативного источника нейтронов (ПИН). Показано, что разработку можно использовать для обнаружения делящихся материалов без определения их изотопного состава при досмотре ручной клади пассажиров, почты и т. д. Кроме того, комплекс ПИН позволит косвенно указывать на возможное присутствие в исследуемом объеме химического взрывчатого вещества, а также кадмия и бора, которые, возможно, скрывают делящиеся элементы от обнаружения. Даны рекомендации по использованию наиболее эффективных инструментов и оборудования. 2020 Article On the multipurpose use of a portable neutron source / E.L. Kuplennikov, A.N. Vodin, O.S. Deiev, S.S. Kandybei, S.N. Olejnik, A.F. Stoyanov, I.S. Timchenko, V.S. Trubnikov, V.A. Tsymbal // Problems of atomic science and tecnology. — 2020. — № 3. — С. 163-167. — Бібліогр.: 20 назв. — англ. 1562-6016 PACS: 07.85.Fv, 61.80.Cb https://nasplib.isofts.kiev.ua/handle/123456789/194548 en Вопросы атомной науки и техники application/pdf Національний науковий центр «Харківський фізико-технічний інститут» НАН України |
| institution |
Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| collection |
DSpace DC |
| language |
English |
| topic |
Application of nuclear methods Application of nuclear methods |
| spellingShingle |
Application of nuclear methods Application of nuclear methods Kuplennikov, E.L. Vodin, A.N. Deiev, O.S. Kandybei, S.S. Olejnik, S.N. Stoyanov, A.F. Timchenko, I.S. Trubnikov, V.S. Tsymbal, V.A. On the multipurpose use of a portable neutron source Вопросы атомной науки и техники |
| description |
The possibility of creating a multipurpose complex for generating a reference field of thermal neutrons based on a portable neutron source (PNS) is considered. It has been shown that our method can be used to detect fissile materials without determining their isotopic composition during an inspection of the hand luggage of passengers, mail,etc. The PNS multipurpose complex will allow to indirectly indicating the possible presence of chemical explosives in the test samples, as well as cadmium and boron, which possibly hide fissile elements from detection. The paper gives recommendations on the use of the most effective instruments and equipment. |
| format |
Article |
| author |
Kuplennikov, E.L. Vodin, A.N. Deiev, O.S. Kandybei, S.S. Olejnik, S.N. Stoyanov, A.F. Timchenko, I.S. Trubnikov, V.S. Tsymbal, V.A. |
| author_facet |
Kuplennikov, E.L. Vodin, A.N. Deiev, O.S. Kandybei, S.S. Olejnik, S.N. Stoyanov, A.F. Timchenko, I.S. Trubnikov, V.S. Tsymbal, V.A. |
| author_sort |
Kuplennikov, E.L. |
| title |
On the multipurpose use of a portable neutron source |
| title_short |
On the multipurpose use of a portable neutron source |
| title_full |
On the multipurpose use of a portable neutron source |
| title_fullStr |
On the multipurpose use of a portable neutron source |
| title_full_unstemmed |
On the multipurpose use of a portable neutron source |
| title_sort |
on the multipurpose use of a portable neutron source |
| publisher |
Національний науковий центр «Харківський фізико-технічний інститут» НАН України |
| publishDate |
2020 |
| topic_facet |
Application of nuclear methods |
| url |
https://nasplib.isofts.kiev.ua/handle/123456789/194548 |
| citation_txt |
On the multipurpose use of a portable neutron source / E.L. Kuplennikov, A.N. Vodin, O.S. Deiev, S.S. Kandybei, S.N. Olejnik, A.F. Stoyanov, I.S. Timchenko, V.S. Trubnikov, V.A. Tsymbal // Problems of atomic science and tecnology. — 2020. — № 3. — С. 163-167. — Бібліогр.: 20 назв. — англ. |
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ISSN 1562-6016. ВАНТ. 2020. №3(127) 163
ON THE MULTIPURPOSE USE OF A PORTABLE NEUTRON SOURCE
E.L. Kuplennikov, A.N. Vodin, O.S. Deiev, S.S. Kandybei, S.N. Olejnik,
A.F. Stoyanov, I.S. Timchenko, V.S. Trubnikov, V.A. Tsymbal
National Science Center “Kharkov Institute of Physics and Technology”, Kharkiv, Ukraine
E-mail: kupl@kipt.kharkov.ua
The possibility of creating a multipurpose complex for generating a reference field of thermal neutrons based on
a portable neutron source (PNS) is considered. It has been shown that our method can be used to detect fissile mate-
rials without determining their isotopic composition during an inspection of the hand luggage of passengers, mail,
etc. The PNS multipurpose complex will allow to indirectly indicating the possible presence of chemical explosives
in the test samples, as well as cadmium and boron, which possibly hide fissile elements from detection. The paper
gives recommendations on the use of the most effective instruments and equipment.
PACS: 07.85.Fv, 61.80.Cb
1. CREATION OF A REFERENCE
NEUTRON FIELD
Laboratory practice shows, that the most accessible
and widely used devices for calibrating and studying the
parameters of detectors are constructions based on ref-
erence neutron fields of radionuclide sources. This is
because by placing emitters in different moderating me-
diums, it is possible to create a reference radiation field
with different characteristics. A hydrogen-containing
medium, most frequently polyethylene, is used as a
moderator. The nomenclature of such sources is exten-
sive. Their properties depend on the radioisotope used,
core size, design, materials used, etc. Most often, two
types of reference fields based on certified fast neutron
emitters, such as 252Cf or 239Pu-В, are preferred.
In [1], the 239Pu-Ве source of fast neutrons was used
to determine the dose of thermal neutrons. It was placed
in a polyethylene sphere with a diameter of 190 cm and
with a cylindrical cavity in the center with a diameter of
58.5 mm and a height of 123 mm [2]. The thermal neu-
trons flux density Ф at a distance R from the center of
the sphere was calculated by the formula
Ф = 0.11/(4R2). The ratio of the thermal neutrons
flux to the total flux of the 239Pu-Ве source was taken
equal to 0.11 with an error of 7% [2].
Test measurements were carried out in an open 2
geometry above a concrete floor level at 150 cm height.
To check the reproducibility of the results in different
conditions and to exclude the influence of a geometric
factor arising at short distances, the DKS-96 dosimeter
sensor, was placed at distance R = 70, 150, and 300 cm.
DKS-96 dosimeter calibrated in a way to have an error
of 10%. For a given geometry condition one can treat
the radioactive source and the detector as a point like
objects and at the same time, the contribution of the
dispersed radiation does not exceed 2%.
Note that neutron sources were also created based on
linear electron accelerators. For example, a facility for
generating thermal 0.510-3…0.5 eV and epithermal
neutrons 0.4 eV…20 keV [3], based on the use of de-
layed fission neutrons, was proposed at the NSC KIPT
[3]. Neutrons were obtained upon activation of a 238U
target with 2% enrichment of 235U by an electron beam.
After 3 minutes of irradiation, the sample becomes a
source of delayed neutrons and is automatically dumped
into the receiver of thermal and epithermal neutrons. A
preliminary experiment was conducted on an electron
beam of 20 MeV, with a power of 9 W. The delayed neu-
tron flux density was 610-5 n∙cm-2∙s-1. The magnitude
(2…3)109 n∙cm-2∙s-1 required for neutron capture therapy
is planned by the authors by increasing the 235U enrich-
ment to 20% and the beam power to 1.5…3 kW.
In current work, it is proposed to obtain a thermal
neutrons reference field based on a polyethylene mod-
erator-sphere and a portable neutron source (PNS) [4, 5]
under the condition of a stable neutron flux with accu-
racy no worse than that of certified radioisotope
sources. Note that, as in any other moderator, the ther-
mal spectrum of PNS will be enriched in neutrons of
higher energies, including (10 eV…5 keV) range.
The principle of operation of PNS is as follows. Ac-
celerated deuterons of the cascade accelerator are di-
rected into a narrow ion guide, passing through which,
the particles are focused on a thick 9Be target 1010 mm
in size. Neutrons are generated as a result of the reaction
2H + 9Be → 10B + n. The length of the accelerating tube
is 0.6 m. The distance between the exit point from the
accelerator gap and the target is ≤ 0.4 m. The beam di-
ameter on the target is 6.8 mm. The expected neutron
intensity is 109 ns-1 at an angle of 4, the average en-
ergy is 2.5 MeV.
The advantage of this design is the absence of a
powerful radiation source since neutrons are created
only during the authorized inclusion of a cascade accel-
erator. Also, the use of isotopes is much more expensive
than the work of PNS. The main types of sources that
are produced in Russia and their characteristics are
given in [5, 6].
Since the expected yield flux of fast neutron from
9Be(d,n) reaction (about 109 ns-1) is higher than that of
239Pu-Ве (up to (5.001.00)107 ns-1) and also higher
then 252Cf (2.1105…2.7107) ns-1, one can expect that
the generation of the thermal neutron with the help of
polyethylene sphere will be correspondingly higher. The
main components of the PNS are shown in Fig. 1.
The size of the polyethylene sphere can be estimated
from an analysis of the energy dependence of the detec-
tor sensitivity (EDoS) obtained by irradiating the sphere
with an external certified radioisotope source, for exam-
ple, 239Pu-Ве.
Fig. 2 shows EDoS measured by the LiJ(Eu) crystal
[7] as a function of the diameter of the polyethylene
sphere and the neutron energy En.
ISSN 1562-6016. ВАНТ. 2020. №3(127) 164
Fig. 1. Schematic view of PNS complex:
1 deuteron source; 2 the outer shell; 3 deuteron
beam; 4 accelerating electrodes; 5 vacuum tube;
6 gradient rings; 7 – Elegaz; 8 vacuum pump;
9 ion channel; 10 water
Fig. 2. EDoS for LiJ(Eu) detector as a function of En
As we can see, at sphere diameter of about 20 cm,
external neutrons with an average energy of
(1…4.5) MeV generates the maximum number of
thermal neutrons in the center of the sphere. Similar
dependencies were measured using various neutron
counters, and also were calculated based on modern
mathematical models. In particular, in [7], EDoS esti-
mates have been done for detectors made from indium
foils. The calculations were done also for proportional
3He(n,p)3H counter. The sensitivity matrix was calcu-
lated using the MCNP and HADRON models. It turned
out that in all cases, with a sphere diameter of 20 cm,
the maximum number of thermal neutrons generated by
the 239Pu-Ве source is observed in the center of the
sphere. When the 239Pu-Ве radioisotope is placed in the
center of the sphere, the PE layer for optimal neutron
deceleration should be 20 cm. Since the average neu-
tron energy of the PNS En 2.5 MeV is in the region of
the maximum EDoS, the optimal moderator layer neces-
sary to obtain the highest number of thermal neutrons in
the center of the sphere should be about 20 cm.
To minimize the leakage of thermal neutrons from
the sphere, it should be surrounded by a neutron reflec-
tor: D2O heavy water, 9Be beryllium, or 12C graphite.
The most practical and relatively cheap material is 12C.
In the process of collisions with nuclei, a thermal neu-
tron has 999 chances out of 1000 to scatter and only 1
chance out of a thousand to be absorbed [8]. The reflec-
tivity of carbon at a thickness of 40 cm is 0.892. There-
fore, a layer of ≤ 40 cm is sufficient for most of the
thermal neutrons to be reflected.
To create a reference field of thermal neutrons based
on a polyethylene moderator-sphere and PNS, it is nec-
essary to take the following steps: a) to develop and
create a neutrons moderator, including a 12C reflector;
b) estimate the deceleration, absorption, and yield of
neutrons from the polyethylene sphere, including the
reflector; c) find the analytical dependence of the flux
density of the thermal neutrons depending on the dis-
tance to the irradiated object. Testing of the prototype
should be done at the experimental area of RDC “Ac-
celerator” NSC KIPT after preparation and implementa-
tion of all necessary technical and economic require-
ments.
2. ESTIMATION OF DECAYING MATERIAL
DETECTION PROBABILITY
A wide network of transport highways, a significant
number of boundary checkpoints increases the chance
of unauthorized movement of nuclear materials, explo-
sives, drugs. Only the introduction of modern detection
systems will allow us to successfully counteract the
smuggling of prohibited goods. Special attention at air-
port custom terminals is paid to detection of fissile ma-
terials, explosives, drugs (since approximately half of
the total number of incidents of the movement of pro-
hibited substances is their placement in hand luggage
[9]). There are many nuclear-physical methods for solv-
ing this problem, and one of them is the activation of
cargo by thermal neutrons, registration, and analysis of
induced reaction products.
Typically, to obtain the thermal neutrons flux neces-
sary to trigger a forced decay of nuclear materials, stan-
dard fast neutrons emitters based on the (,n) reaction
of spontaneous 252Cf decay are used. The second option
is the pulse generators. The (,n)-emitters have a con-
tinuous spectrum and a high level of -background.
These sources in various modifications are used in many
fields of modern science and technology [5, 10].
Existing non-destructive testing methods are aimed,
first of all, at determining the mass and composition of
decaying materials in confined volumes that cannot be
opened. If we consider the installations of the first line
of defense used to prevent the circulation of fissile ele-
ments (without determining the isotopic content), then
their design and operation must satisfy the following
basic conditions [11]:
during the measurement time (about 5…7 s), it is
necessary to obtain the information concerning the pres-
ence of decaying materials in the inspected object with a
confidence level of 99.9%;
the output of the source (107…108) ns-1 (deter-
mined by the radiation situation of the environment);
option to turn off the radiation source between
working cycles;
impossibility of radioactive contamination even in
the case of the destruction of a neutron source;
the simplicity of design, the small size of radiation
protection and low cost of installation;
ISSN 1562-6016. ВАНТ. 2020. №3(127) 165
acceptable operating time without replacing the
radiation source;
absence of special requirements for the storage
room of radiation source.
Conclusions from [11]:
a) For the conditions described above, there is no ra-
diation hazard associated with the exposure of baggage
materials.
b) Ideally, the probability of detection should not
depend on the position of decaying material inside the
baggage. But in real conditions, there is some no uni-
form distribution of the flux density of the TN due to
the position of the source relative to the inspected vol-
ume. However, according to estimates, the field gradient
of the TN is small.
c) Calculations and experimental studies have con-
firmed the possibility of the creation of a facility for the
detection of decaying nuclei using hydrogen-containing
moderators and pulsed neutron generators with an out-
put of 107…108 s-1. The content of 235U, and 239Pu with a
mass of 5…10 g can be detected in 5…7 s of operation
with a probability of 99.9%”.
The requirements described above for the successful
operation of the facility for the determination of decay-
ing materials are fully consistent with the operating
modes of PNS. Therefore, this article focuses on the
possibility of detection of radioactive nuclides 233,235U
and 239Pu, since these are the main components of nu-
clear reactors and the main components of weapons of
mass destruction. Neutrons of any energy can trigger the
decay of nuclei, but the largest cross-section corre-
sponds to TN. At En = 0.025 eV: (5264), (5816), and
(75110) barn (b), respectively, which is hundreds of
times higher than the similar values for fast neutrons.
Interacting with a thermal neutron, the nucleus divides,
emitting in a time of 10…14 s, instantaneous neutrons
with maximum energy in the range of 0.6…0.8 MeV,
the average energy of 2 MeV and -quanta. The aver-
age number of neutrons for one decay event for
En = 0.025 eV: 2.50, 2.43, 2.84 [12]. The energy spec-
trum of neutrons from decays of 233 U, 235U, and 239Pu is
shown in Fig. 3. These spectra are close to each other
[10, 12]. The experimental points are well described by
the distribution
)/()( TE
n
neETN , (1)
where T is the temperature of the spectrum. In this case,
T = 1.31, 1.29, and 1.33, respectively.
Fig. 3. The energy spectrum of neutrons from decay
The proposed experiment is a sequential series of
procedures:
1. A source of FN from PNS with an intensity of
109 ns-1 is placed in the center of the polyethylene
sphere.
2. The neutron flux slowed down to the thermal en-
ergies and directed to the object under study.
3. If there are decaying nuclei in the volume, they
interact with TN, as a result of this interaction the nuclei
fall apart, forming decay fragments, instantaneous and
delayed neutrons, -particles, antineutrinos, -quanta.
On average, from 7 to 10 -quanta are formed per
one division, and their average energy is about 1 MeV.
The number of delayed neutrons, normally, is 1% of
the number of instant ones. They are emitted by decay
products over a period from hundreds of milliseconds
up to 54…56 s. Their average energy is small. For ex-
ample, for 235U it is equal to 0.45 MeV.
Most nuclear materials emit 10 times more -quanta
than neutrons, which sometimes requires the use of a
protective shield. When a detector is irradiated with
neutrons with energy of 1 MeV in the presence of -
radiation with an energy of 1 MeV, protection from the
lead of 5 cm thickness absorbs 0.1% of neutrons and
90% of -quanta [13].
As mentioned above, the instantaneous neutron flux
should first be slowed down, and only then registered.
For slowing down of fast neutrons with energies
1…2 MeV to thermal energies, it is recommended to
use polyethylene (for gas-filled boron or 3He counters
this can be a cylinder with a diameter of 13 cm [14]).
An important property of PE is that it accumulates most
of the thermal neutrons at a certain depth. Particles have
already experienced enough collisions and lost almost
all of their kinetic energy. If the detector is placed in
this region, the probability of detecting particles be-
comes optimal. The counter is shielded from the back-
ground of the thermal neutrons by a thin layer of cad-
mium. Cadmium strongly absorbs neutrons with energy
≤ 0.4 eV and weakly with En 0.6 eV [15]. Boron can
be also used for this purpose, but cadmium is more ef-
fective in the case of purely thermal neutrons, while
boron shields neutrons were better in the energy range
from 0.1 to 10 eV [15].
Widely used counters for detecting TN are devices
based on a LiJ(Eu) crystal or a proportional 3He detec-
tor. Detector based on LiJ(Eu) has the following pa-
rameters: an energy resolution of 9…10% for thermal
neutrons peak, luminescence time is 1 μs, wavelength
of the emitted light is max = 460 nm, and time resolu-
tion is 0.3 μs. Scintillators are usually made in the
form of washers with a diameter of 10…40 mm and a
thickness of d 2…40 mm, which allows them to be
placed directly on the photomultiplier tube. Particle de-
tection efficiency () for natural natLi with a thickness of
d = 1 cm is 69% and 90% for d = 2 cm. When
enriched with 6Li 94…96%, 98% [16]. Due to the
high cross-section for the interaction of for thermal neu-
trons with 3He 5330 b, proportional 3He counters are
very effective for neutron detection. It has a sensitivity
to -quanta with an energy of 1 MeV is of the order of
0.0001. 3He-detectors are relatively easy to operate and
ISSN 1562-6016. ВАНТ. 2020. №3(127) 166
highly stable. They withstand irradiation to a fluence of
1013 Bncm-2 without serious radiation damage and
provide discrimination of -fields with a dose rate up to
1 Rh-1 [14].
To register neutrons, it is useful to create a set of de-
tectors that form a closed system around the measuring
chamber. For example, in [11], 18 helium counters were
used. In this case, at the first stage, the simplest set can be
composed of three long metal proportional 3Не-counters
SNM-66. Diameter 25.5 mm, length 601.5 mm, operating
voltage 1600 V, efficiency to TN 80% [17]. This sample
was selected taking into account the average size of air-
plane hand luggage allowed 554020 cm (in length,
width, height) or 115 cm in the sum of three measure-
ments [18].
Among the 233,235U and 239Pu nuclei, the most impor-
tant in terms of practical use is 239Pu. The demand for it
is constantly growing at the beginning of the 21-st
century, the annual net increase in plutonium was
100 t. The critical mass of a sphere made of “pure”
239Pu metal with a 9Ве reflector 32 cm thick is 2.47 kg
only [19]. By “pure” is meant the composition: 239Pu
(90…95)%, 240Pu (1…7)%, the content of other iso-
topes does not exceed tenths of a percent.
At the initial stage of the experimental study, 239Pu is
more promising than 233,235U due to the maximum cross-
section, the largest neutron yield per one decay event,
and the presence of resonance in the cross-section at an
energy of 0.3 eV [12] (Fig. 4).
Fig. 4. Decay cross-section of 235,238U, 239Pu, and 232Th
as a function of neutron energy.
Dotted line resonance region
Creating the complex, the main efforts of the first
stage of work will be concentrated at the justification of
the use of certain structural elements (with the help of
modern software), their sizes and location in space; de-
velopment and assembly of a thermal neutrons genera-
tor based on PNS; estimation of conditions for detecting
a minimum number of basic decaying elements; creat-
ing reliable radiation protection. It is planned to carry
out commissioning, testing and preliminary commis-
sioning of the complex at the test system, the main ele-
ments of which are the cascade generator itself, PE
moderator, 12C reflector, a set of sensitive detectors and
radiation protection. The next stage of work will be ex-
periments to detect the minimum amount of nuclear
materials in 5…7 s. The work also needs to find out the
probability of detecting prohibited materials and false
alarm in %.
3. ADDITIONAL OPTIONS
Technical advances in the miniaturization of explo-
sive materials (EM) make the task of their detection
very important. The main unmasking sign of EM is the
certain composition of its components: hydrogen, car-
bon, nitrogen, and oxygen, which comes in a certain
ratio of the concentration of individual nuclei: O/N 1-3,
C/N 0.5-2.5, H/ N 1-2. The main component of the
structural formula is nitrogen (1021 cm-3). For example,
TNT contains 18% nitrogen, tetryl 24%, hexogen 37%,
octogen 39%, nitroglycerin 18%, etc. The nitrogen con-
tent in the natural mixture is 99.63%.
One possible option to solve the problem is to use
the radiation capture of TN (TNA technology). To de-
termine the concentration of 14N nuclei, the reaction
14N(n,)15N is used. The -radiation of a daughter nu-
cleus with the energy of 10.824 MeV has a high inten-
sity of 14% per neutron captured. The -quanta are
fairly reliably recorded at a relatively low neutron flux
intensity of 6107 ns-1.
To test the technology, two prototypes were created.
In one of them, 252Cf was used. The other was a Kaman
A-711 type neutron generator (reaction (d,d)). TNA
tests were successful, which led to many years of suc-
cessful usage of it at all US airports. In 1996, over 106
pieces of luggage were checked. The disadvantage of
the method [9, 20] is the ability to detect nitrogen only.
Also, this method is suffering from the presence of in-
terference from the uncontrolled contribution of -
quanta Е = 10038 and 9298 keV of 58,55Fe isotopes from
related objects. More promising future technology is
based on fast neutrons and nuclear resonance absorption.
The decaying materials can be smuggled through
control points using coatings that absorb TN (boron,
cadmium). An alternative detection system should be
used. In the 10B(n, )7Li reaction, -quanta are emitted
with an energy of 477.6 keV [16] (10B capture cross-
section is 4010 b). The thermal neutrons capture cross-
section of natural natCd 2550 b is mainly due to the
113Cd isotope (12.3%), the cross-section of this isotope
is about 20.000 b. In the reaction 113Cd(n,)114Cd, sev-
eral gamma-lines are generated. The most intense is
Е = 558.6 keV [21].
In this particular case, the most suitable -
spectrometer would be a planar detector made of high-
purity germanium. It has the best energy resolution and
is preferred for detailed spectrometry. Radiation damage
manifests itself only starting from an intense neutron
flux of ≥ 109 ncm-2.
CONCLUSIONS
A multifunctional complex for generating a reference
field of thermal neutrons based on a portable neutron
source is proposed. The possibility of detection of decay-
ing materials without determining their isotopic composi-
tion during the inspection of hand luggage of passengers,
mail, etc is discussed. The complex allows to indirectly
indicate the possible presence of chemical explosives,
also cadmium or boron, in the test volume, which are
designed to hide decaying elements from detection.
ISSN 1562-6016. ВАНТ. 2020. №3(127) 167
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Article received 30.03.2020
О МНОГОЦЕЛЕВОМ ИСПОЛЬЗОВАНИИ ПОРТАТИВНОГО ИСТОЧНИКА НЕЙТРОНОВ
Э.Л. Купленников, А.Н. Водин, А.С. Деев, С.С. Кандыбей, С.Н. Олейник, А.Ф. Стоянов, И.С. Тимченко,
В.С. Трубников, В.А. Цымбал
Рассмотрена возможность создания многофункционального комплекса для генерации опорного поля те-
пловых нейтронов на основе портативного источника нейтронов (ПИН). Показано, что разработку можно
использовать для обнаружения делящихся материалов без определения их изотопного состава при досмотре
ручной клади пассажиров, почты и т. д. Кроме того, комплекс ПИН позволит косвенно указывать на воз-
можное присутствие в исследуемом объеме химического взрывчатого вещества, а также кадмия и бора, ко-
торые, возможно, скрывают делящиеся элементы от обнаружения. Даны рекомендации по использованию
наиболее эффективных инструментов и оборудования.
ПРО БАГАТОЦІЛЬОВЕ ВИКОРИСТАННЯ ПОРТАТИВНОГО ДЖЕРЕЛА НЕЙТРОНІВ
Е.Л. Купленніков, О.М. Водін, О.С. Дєєв, С.С. Кандибей, С.М. Олійник, О.Ф. Стоянов, І.С. Тімченко,
В.С. Трубніков, В.О. Цимбал
Розглянута можливість створення багатофункціонального комплексу для генерування опорного поля те-
плових нейтронів на базі портативного джерела нейтронів (ПДН). Показано, що розробка може бути вико-
ристана для виявлення матеріалів, що діляться, без визначення їх ізотопного складу при огляді ручної по-
клажі пасажирів, поштових відправлень і т. п. Крім того, комплекс ПДН дозволить побічно вказати на
можливу присутність у досліджуваному об’ємі хімічної вибухової речовини, а також кадмію і бору, які
можливо приховують елементи, що діляться, від виявлення. Дані рекомендації по застосуванню найбільш
ефективних приладів та обладнання.
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