CPNA-method for ES detection using hydrogen ion accelerators operating in batch-pulse mode
A new nuclear method CPNA (complex pulsed neutron analysis) for detection of explosive substance (ES) is suggested. The essence of the method is the following. Information on ES presence can be obtained from analysis of energy spectra of γ-quanta produced as a result of nuclear reactions of neutro...
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irk-123456789-790652015-03-26T03:01:47Z CPNA-method for ES detection using hydrogen ion accelerators operating in batch-pulse mode Gavrish, Yu.N. Sidorov, A.V Fialkovsky, A.M. Применение ускоренных пучков A new nuclear method CPNA (complex pulsed neutron analysis) for detection of explosive substance (ES) is suggested. The essence of the method is the following. Information on ES presence can be obtained from analysis of energy spectra of γ-quanta produced as a result of nuclear reactions of neutron pulse radiation interaction with nuclei of characteristic elements constituents of ES. Based on optimizing calculations of neutron radiation parameters to provide most effective detection of ES, a batch-pulse operating mode of the hydrogen ion accelerator has been suggested. Запропоновано новий ядерно-фізичний метод виявлення вибухових речовин (ВР). Інформація про наявність ВР може бути отримана з аналізу енергетичних спектрів гамма-випромінювання, отриманих у результаті ядерних реакцій взаємодії імпульсного періодичного нейтронного випромінювання з ядрами характерних елементів, що входять до складу ВР. На підставі розрахунків оптимізації параметрів нейтронного випромінювання для ефективного виявлення вибухових речовин запропоновано використовувати пакетно-імпульсний режим роботи прискорювача іонів водню. Предложен новый ядерно-физический метод обнаружения взрывчатых веществ (ВВ). Информация о наличии ВВ может быть получена из анализа энергетических спектров гамма-излучения, образуемых в результате ядерных реакций взаимодействия импульсного периодического нейтронного излучения с ядрами характерных элементов, входящих в состав ВВ. На основании расчетов оптимизации параметров нейтронного излучения для эффективного обнаружения взрывчатых веществ предложено использовать пакетно-импульсный режим работы ускорителя ионов водорода. 2004 Article CPNA-method for ES detection using hydrogen ion accelerators operating in batch-pulse mode / Yu.N. Gavrish, A.V. Sidorov, A.M. Fialkovsky // Вопросы атомной науки и техники. — 2004. — № 1. — С. 175-177. — Бібліогр.: 2 назв. — англ. 1562-6016 PACS: 29.17.+w http://dspace.nbuv.gov.ua/handle/123456789/79065 en Вопросы атомной науки и техники Національний науковий центр «Харківський фізико-технічний інститут» НАН України |
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Применение ускоренных пучков Применение ускоренных пучков |
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Применение ускоренных пучков Применение ускоренных пучков Gavrish, Yu.N. Sidorov, A.V Fialkovsky, A.M. CPNA-method for ES detection using hydrogen ion accelerators operating in batch-pulse mode Вопросы атомной науки и техники |
| description |
A new nuclear method CPNA (complex pulsed neutron analysis) for detection of explosive substance (ES) is
suggested. The essence of the method is the following. Information on ES presence can be obtained from analysis of
energy spectra of γ-quanta produced as a result of nuclear reactions of neutron pulse radiation interaction with nuclei
of characteristic elements constituents of ES. Based on optimizing calculations of neutron radiation parameters to
provide most effective detection of ES, a batch-pulse operating mode of the hydrogen ion accelerator has been suggested. |
| format |
Article |
| author |
Gavrish, Yu.N. Sidorov, A.V Fialkovsky, A.M. |
| author_facet |
Gavrish, Yu.N. Sidorov, A.V Fialkovsky, A.M. |
| author_sort |
Gavrish, Yu.N. |
| title |
CPNA-method for ES detection using hydrogen ion accelerators operating in batch-pulse mode |
| title_short |
CPNA-method for ES detection using hydrogen ion accelerators operating in batch-pulse mode |
| title_full |
CPNA-method for ES detection using hydrogen ion accelerators operating in batch-pulse mode |
| title_fullStr |
CPNA-method for ES detection using hydrogen ion accelerators operating in batch-pulse mode |
| title_full_unstemmed |
CPNA-method for ES detection using hydrogen ion accelerators operating in batch-pulse mode |
| title_sort |
cpna-method for es detection using hydrogen ion accelerators operating in batch-pulse mode |
| publisher |
Національний науковий центр «Харківський фізико-технічний інститут» НАН України |
| publishDate |
2004 |
| topic_facet |
Применение ускоренных пучков |
| url |
http://dspace.nbuv.gov.ua/handle/123456789/79065 |
| citation_txt |
CPNA-method for ES detection using hydrogen ion accelerators operating in batch-pulse mode / Yu.N. Gavrish, A.V. Sidorov, A.M. Fialkovsky // Вопросы атомной науки и техники. — 2004. — № 1. — С. 175-177. — Бібліогр.: 2 назв. — англ. |
| series |
Вопросы атомной науки и техники |
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2025-07-06T03:10:17Z |
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2025-07-06T03:10:17Z |
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| fulltext |
CPNA-METHOD FOR ES DETECTION USING HYDROGEN ION
ACCELERATORS OPERATING IN BATCH-PULSE MODE
Yu.N. Gavrish, A.V. Sidorov, A.M. Fialkovsky
The Scientific Research Institute of Electrophysical Apparatus, Scientific Production Complex
of Linear Accelerators and Cyclotrons, Saint-Petersburg, Russia; npkluts@niiefa.spb.su
A new nuclear method CPNA (complex pulsed neutron analysis) for detection of explosive substance (ES) is
suggested. The essence of the method is the following. Information on ES presence can be obtained from analysis of
energy spectra of γ-quanta produced as a result of nuclear reactions of neutron pulse radiation interaction with nuclei
of characteristic elements constituents of ES. Based on optimizing calculations of neutron radiation parameters to
provide most effective detection of ES, a batch-pulse operating mode of the hydrogen ion accelerator has been sug-
gested.
PACS: 29.17.+w
INTRODUCTION
The problem of the detection of explosive sub-
stances (ES) is currently central in the context of in-
creasing number and variety of forms of terrorist acts
assassinated in many regions and countries all over the
world, Russia included. Especially dangerous is use of
ES at hijacking and in crowded places. To fight success-
fully against these crimes, corresponding services
should be equipped with effective technical means for
remote detection of masked ES.
Previously, the problem of ES detection consisted in
the search of metallic shells of grenades or mines made of
traditional explosive materials, such as dynamite, trinitro-
toluene, etc. At present, the problem is much more so-
phisticated because of application of non-shell ES, for ex-
ample, on the basis of plastic explosive charges of C-4,
Semtex or Detasheet type. These materials are far beyond
dynamite and trinitrotoluene in destructive effect, and
they can be produced as plates about 5 mm in thickness
(“sheet” ES) practically of any shape.
Nuclear methods are highly promising for detection
of explosive substances as the majority of ES offers
unique combination of high concentrations of carbon,
nitrogen and oxygen atoms. High concentration of nitro-
gen in an inspected object is an indication of probable
presence of ES, and high concentrations of carbon, ni-
trogen and oxygen practically unambiguously testify ES
presence. It should be emphasized that only nuclear
methods allow one to most effectively detect non-shell
plastic explosives and masked ES. Only neutron-radia-
tion method for detection of high nitrogen concentration
(the TNA method) has been implemented in practice;
unfortunately, experience has demonstrated its unallow-
able high level of false alarms. Nuclear methods apply-
ing fast neutrons as the probing radiation are considered
most promising. The Pulsed Fast Neutron Analysis (the
PFNA method) provides maximum sensitivity of ES de-
tection.
A great number of methods and means for ES de-
tection have been suggested to date. However, at
present, there is no such a method that can provide
100% probability of ES detection. Therefore, new meth-
ods are still being devised including nuclear ones offer-
ing higher efficiency of ES detection. It should be em-
phasized that only nuclear methods are effective in de-
tection of masked ES.
CPNA-METHOD FOR ES DETECTION
We analyzed the experience gained when devising
methods and creating means for ES detection taking into
account the potentialities of modern spectrometric appa-
ratus, which makes possible measurements of photon
energy distributions at high background with a high lev-
el of reliability. As a result a new method [1] has been
suggested the essence of which is the following (fig.1).
Fig.1. Time chart of neutron source: t1 - time of mea-
surements of γ-radiation produced as a result of inelas-
tic scattering of fast neutrons by nuclei of ES typical el-
ements (nitrogen, oxygen, carbon); td - time delay due
to neutron thermalization; t2 - time of measurements of
γ-radiation produced as a result of thermal neutrons
capture with nitrogen nuclei; t3 - time of measurements
of γ-radiation of short-lived radionuclide decay (oxy-
gen, chlorine, etc.); tFS - time of fission substances mea-
surements; T - neutron pulse repetition rate
Information on ES presence can be obtained from
analysis of energy spectra of γ-quanta produced as a re-
sult of nuclear reactions of neutron pulse periodic radia-
tion interaction with nuclei of characteristic elements-
constituents of ES. During pulses of neutron radiation,
energy spectrum of γ-quanta produced as a result of re-
actions of inelastic scattering of fast neutrons by nuclei
of nitrogen, oxygen and carbon is measured. Between
the pulses, are measured energy characteristics of γ-
quanta produced as a result of reactions of neutrons’ ra-
diation capture with nitrogen nuclei (14N(n,γ)15N) and
energy spectra of γ-quanta of short-lived radionuclides’
decay. Short-lived radionuclides are formed under neu-
trons’ interaction with oxygen nuclei (16O(n, p) 16N(β-,γ)
, T1/2=7,13 and chlorine (an impurity used at production
of new ES) 37Cl(n,α)34P(β-,γ) T1/2=12,4 and 37Cl(n, γ)38m-
Cl T1/2=0,71c).
Table 1. Energies of characteristic γ-quanta for some
elements
Element γ-quanta energy, MeV
16О 6.13
14N 5.11; 2.31; 1.63
12С 4.44
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PROBLEMS OF ATOMIC SIENCE AND TECHNOLOGY. 2004. № 1.
Series: Nuclear Physics Investigations (42), p.175-177. 175
mailto:npkluts@niiefa.spb.su
27Al 3.00; 2.50; 2.30; 2.21; 1.72; 1.01; 0.84
56Fe 2.60; 2.27; 2.11; 1.81; 1.24; 1.04; 0.85
35,37Cl 3.16; 3.10; 2.65; 2.35; 1.99; 1.76; 1.22;1.19
Any element can be detected from characteristic γ-
quanta produced as a result of inelastic scattering of
neutrons. For example, Table 1 demonstrates energies
of characteristic γ-quanta produced under inelastic scat-
tering of 3…12 MeV neutrons by nuclei of some ele-
ments.
As a result of radiation capture of thermal neutrons
with nuclei of 14N (14N (n, γ)15N), 10.83 MeV γ-quanta
are produced. The content of 14N isotope in a natural
mixture is 99.63%. Reaction cross-section of neutrons’
radiation capture with nitrogen nuclei is smaller with
higher energy; for thermal neutrons it is 75 mb. Radia-
tion spectrum of 15N-daughter nucleus has a γ-line with
an energy of 10,83 MeV and intensity of 14% per one
captured neutron. It should be noted that this energy is
one of the highest energies of γ-quanta produced under
radiation capture of thermal neutrons with different nu-
clei.
Activation analysis holds a special position among
modern analytical methods used for determination of el-
ement composition of substances as it allows one to ob-
tain results appreciably surpassing those obtained with
methods of analytical chemistry in sensitivity, accuracy
and rapidness. Activation analysis, which can use prac-
tically all the types of nuclear interactions, is performed
in two stages. First-irradiation of an object with a flow
of activating radiation and then-study of characteristics
of the induced activity The majority of procedures for
measuring the induced activity are based on spectrome-
try of γ-quanta using scintillation or semiconductor
spectrometers. As a result of activating radiation inter-
action with nuclei of various elements, a large amount
of radionuclides is produced, as a rule, including short-
lived ones. Under all other conditions being equal, larg-
er measured friendly signal corresponds to lower period
of half-decay.
Half-decay classification of nuclides in the neutron-
activation analysis depends on conditions of the experi-
ment, in particular, time parameters of the source of ra-
diation and time of measurement – tm. In the general
case, as short-lived nuclides are considered those for
which λ tm >1, where λ is the decay constant related to
the half-decay period via ratio λ=Ln (2)/T1/2. Nowadays,
the nuclides which half-decay period is within the range
of 10-3 with <T1/2 <102s are considered as short-lived
ones.
The use of pulse-periodic source allows the applica-
tion of cyclic method of neutron-activation analysis
from short-lived isotopes. The essence of the method
consists in multiple repetition of irradiation-measure-
ment cycle that provides appreciable advantages, espe-
cially, when analysis is performed from short-lived nu-
clides: statistical error of measurements is significantly
reduced, sensitivity and accuracy of the analysis are
much more higher. The following time mode of the
analysis is suggested. An object under inspection is irra-
diated with a pulse flow of neutrons. Between pulses the
induced activity is measured. Then irradiation–measure-
ment cycles are repeated.
Table 2 presents some elements, which can be de-
tected with the neutron-activation analysis from short-
lived isotopes at energy of neutron radiation up to
12 MeV [2]. Only elements being of interest for ES de-
tection are shown (oxygen and chlorine, used at produc-
tion of modern explosive substances) and precious met-
als: silver, gold and platinum.
Table 2
Z Reaction Т1/2, с Eγ, MeV (relative in-
tensity, %)
O O16(n,p)N16 7,13 7,122(5); 6,134(69)
Cl Cl37(n,γ)Cl38m 0,71 0,671(99,9)
Cl Cl37(n,α)P34 12,4 4,00(0,2); 2,127(15)
Ag Ag109(n,γ)Ag110 24.4 0.658(5,6)
Au Au197(n,n’)Au197 7,2 0,278(72,5);
0,13(3,2)
Pt Pt198(n,γ)Pt199m 14 0.393(83), 0.032(5)
Detailed consideration of the activation analysis
from short-lived isotopes is given in [2].
NEUTRON SOURCE
Various types of nuclear source can be used for ES
detection. Neutron sources based on the use of radioac-
tive nuclides are simplest in design and application. The
intensity attainable when using a radioactive source is
about 109 n/s. The source occupies quite a small volume
(about 1litre). The main drawback is that isotropic neu-
trons are emitted in rather wide range of energies.
The neutron generator is relatively small, but power
supply and cooling systems make their enlarging contri-
butions to its volume. Neutron generators can operate
both in pulse and continuous modes. Angular distribu-
tion of neutrons is isotropic, and that is a drawback of
the source. Another drawback is short time of tritium
targets running (100 hours). In this connection there ap-
pears a problem of spent tubes or interchangeable tar-
gets disposal. The advantage is that the source can be
“switched off”.
Neutron sources on the basis of charged particle ac-
celerators are the most complicated devices. The accel-
erator offer a possibility to produce neutrons in a wide
range of energies at a relatively low energy spread,
which is its serious advantage. The source anisotropy
increases the neutrons’ escape predominantly in the for-
ward direction. The source can be “switched off’, which
is also significant merit compared to radioactive source.
Thus it has been found out that linear accelerators of
hydrogen ions offer the best capabilities for ES detec-
tion. An example of such an accelerator is a radio fre-
quency accelerator of hydrogen ions designed in NPK
LUTS, the D.V.Efremov Institute (Fig.2).
176
Fig.2. General view of RF accelerator of hydrogen ions
To determine optimal energy parameters of the neu-
tron radiation source, interaction of neutrons with differ-
ent energies with ES (trinitrotoluene C7H5O6N3) has
been studied. Calculations of γ-quanta produced as a re-
sult of neutrons’ inelastic scattering by N, C and O nu-
clei have demonstrated that γ-quanta with energies:
E y =1,64; 2,31; 5,11; 7,03 MeV offer the largest yield
for nitrogen, with Ey = 2,74; 6,13; 6,92 7,12 – for oxy-
gen and with E y = 4,44 and 9,64 MeV – for carbon. Op-
timal energy of the pulse periodic neutron source in-
tended for ES detection using (n,n’) reactions is calcu-
lated such that cross-section of produced γ-quanta for
specified lines is maximum and amounts to 8-12 MeV.
The 16O(n,p)16N reaction cross-section has its maximum
at 12 MeV energy of neutrons. Thus we obtain that 10-
12 MeV energy of the pulse- periodic neutron source is
optimal for ES detection by the suggested method.
Time parameters of the pulse - periodic source of
neutrons have been obtained by minimizing the time for
ES analysis at a specified ES detection limit of 10 g of
trotyl. Simulation of processes of ES-neutrons interac-
tion has shown that optimal time parameters in case of
ES detection by γ-quanta produced as a result of neu-
trons’ inelastic scattering by N, O and C nuclei are: τ∼
1 µs (is defined such that the detector system registers
no more than one quanta, otherwise, the information on
amplitude will be incorrect because of superposition of
two or more events); time interval between pulses is ∼3-
5 µs, the time necessary for generation of spectrometric
signal when registering γ-quanta with a CsI (TI)-based
scintillation detector with decay time of 1 µs.
To attain maximum sensitivity of the neutron-activa-
tion analysis from short-lived isotopes, the dependence of
number of counts on pulsed time parameters: pulse dura-
tion and pulse repetition rate has been studied. It is shown
that the accelerator current pulse duration of tr ∼100 µs at
a pulse repetition rate of v<1000Hz corresponds to the
optimal mode of the neutron-activation analysis from
short-lived isotopes for ES detection.
Taking into account the fact that different time pa-
rameters correspond to the optimal modes of the sources
used for the analysis from non-elastic scattering of fast
neutrons and the neutron-activation analysis of short-
lived isotopes, the batch-pulse operating mode of the
pulse neutron source is suggested.
CONCLUSIONS
As a result of our intensive efforts we have suggest-
ed a new high promising method for ES detection being
an advantageous combination of already known nuclear
methods. Main advantages of the method are:
• higher reliability of ES detection due to the use of
three independent channels, that is PFNA (Pulsed
Fast Neutron Analysis), PTNA (Pulsed Thermal
Neutron Analysis) and short-lived radionuclide
decay;
• may be detection of fissionable substances;
• may be detection of chlorine, which is a compo-
nent of some explosive substances;
• detection of other substances, such as vegetative
drugs, gold, platinum, silver, etc. which are of
interest for customs inspection.
Contraband Detection Technological Complex is de-
signed to detect explosives, fission materials, and in fu-
ture vegetable drugs by .NPK LUTS (Scientific Produc-
tion Complex of Linear Accelerators and Cyclotrons).
REFERENCES
1. M.F. Vorogushin, Yu.N. Gavrish, A.V. Sidorov,
A.M. Fialkovsky. Method of detection of explosives
and fission products. Russian patent № 2150105.
Priority since May 26, 1999 (in Russian).
2. M.F.Borogushin, Yu.N.Gavrish, A.V.Sidorov,
A.M.Fialkovsky. Neutron-activation analysis from
short-lived radionuclides on the basis of linear ion
accelerator: Preprint П-0936. M.: “TSNIIatomin-
form”, 1995.
CPNA-МЕТОД ОБНАРУЖЕНИЯ ВЗРЫВЧАТЫХ ВЕЩЕСТВ C ИСПОЛЬЗОВАНИЕМ
ПАКЕТНО-ИМПУЛЬСНОГО РЕЖИМА РАБОТЫ УСКОРИТЕЛЯ ИОНОВ ВОДОРОДА
Ю.Н. Гавриш, А.М. Сидоров, А.М. Фиалковский
Предложен новый ядерно-физический метод обнаружения взрывчатых веществ (ВВ). Информация о наличии ВВ мо-
жет быть получена из анализа энергетических спектров гамма-излучения, образуемых в результате ядерных реакций
взаимодействия импульсного периодического нейтронного излучения с ядрами характерных элементов, входящих в со-
став ВВ. На основании расчетов оптимизации параметров нейтронного излучения для эффективного обнаружения
взрывчатых веществ предложено использовать пакетно-импульсный режим работы ускорителя ионов водорода.
CPNA-МЕТОД ВИЯВЛЕННЯ ВИБУХОВИХ РЕЧОВИН З ВИКОРИСТАННЯМ ПАКЕТНО-ІМПУЛЬСНОГО
РЕЖИМУ РОБОТИ ПРИСКОРЮВАЧА ІОНІВ ВОДНЮ
Ю.Н. Гавриш, А.М. Сидоров, А.М. Фіалковський
Запропоновано новий ядерно-фізичний метод виявлення вибухових речовин (ВР). Інформація про наявність ВР може
бути отримана з аналізу енергетичних спектрів гамма-випромінювання, отриманих у результаті ядерних реакцій
взаємодії імпульсного періодичного нейтронного випромінювання з ядрами характерних елементів, що входять до
___________________________________________________________
PROBLEMS OF ATOMIC SIENCE AND TECHNOLOGY. 2004. № 1.
Series: Nuclear Physics Investigations (42), p.175-177. 177
складу ВР. На підставі розрахунків оптимізації параметрів нейтронного випромінювання для ефективного виявлення
вибухових речовин запропоновано використовувати пакетно-імпульсний режим роботи прискорювача іонів водню.
178
Introduction
Conclusions
пакетно-импульсного режима работы ускорителя ионов водорода
Ю.Н. Гавриш, А.М. Сидоров, А.М. Фіалковський
|