XRF with a primary X-rays from the target with monoisotopical surface layer
The development is presented of X-Rays fluorescence analysis using as primary source proton induced X-Rays emission. It is offered to make primary target as double-layer using as the backing natural intermixture of isotopes, and as the upper layer - an isotope with the highest threshold of (p,n)-rea...
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Національний науковий центр «Харківський фізико-технічний інститут» НАН України
2016
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| Назва видання: | Вопросы атомной науки и техники |
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irk-123456789-1117422017-01-15T03:02:26Z XRF with a primary X-rays from the target with monoisotopical surface layer Levenets, V. Omelnik, O. Shchur, A. Физика и технология конструкционных материалов The development is presented of X-Rays fluorescence analysis using as primary source proton induced X-Rays emission. It is offered to make primary target as double-layer using as the backing natural intermixture of isotopes, and as the upper layer - an isotope with the highest threshold of (p,n)-reaction for given element. Such target allows to reach lower detection limits by decreasing of background γ-emission from (p,n)-reactions. The making of target from copper, nickel, zirconium, and molybdenum are discussed. The presented approach has been used for elemental analysis of the samples of zirconium compounds and alloys, soils, plants and sediments. Представлена модифікація рентгенофлуоресцентного аналізу з використанням в якості джерела флуоресценції рентгенівське випромінювання, що збуджуване протонами. Запропоновано використовувати первинну мішень з моноізотопним поверхневим шаром і підкладкою з тієї ж речовини з природним вмістом ізотопів. Для виготовлення поверхневого шару використовується ізотоп з найбільшим порогом реакції (p,n)-типу. Така мішень дає змогу знизити границі визначення при елементному аналізі за рахунок зменшення фонового γ-випромінювання з реакцій (p,n)-типу. Обговорено можливість виготовлення первинних мішеней з нікелю, меді, цирконію та молібдену. Запропонований підхід використано для елементного аналізу зразків із сполук та сплавів цирконію, ґрунтів, рослин, донних відкладень. Представлена модификация рентгенофлуоресцентного анализа, использующего как источник флуоресценции рентгеновское излучение, возбуждаемое протонами. Предложено использовать первичную мишень с моноизотопным поверхностным слоем и подложкой из того же вещества с естественным изотопным составом. Для изготовления верхнего слоя используется изотоп с наибольшим порогом реакции (p,n)-типа. Такая мишень позволяет снизить пределы обнаружения при элементном анализе за счет уменьшения фонового γ-излучения из реакций (p,n)-типа. Обсуждена возможность изготовления первичных мишеней из никеля, меди, циркония и молибдена. Представленный подход использован для элементного анализа образцов из соединений и сплавов циркония, почв, растений и донных отложений. 2016 Article XRF with a primary X-rays from the target with monoisotopical surface layer / V. Levenets, O. Omelnik, A. Shchur // Вопросы атомной науки и техники. — 2016. — № 1. — С. 99-101. — Бібліогр.: 3 назв. — англ. 1562-6016 http://dspace.nbuv.gov.ua/handle/123456789/111742 539.534.9/535-34/539.17+543.4 en Вопросы атомной науки и техники Національний науковий центр «Харківський фізико-технічний інститут» НАН України |
| institution |
Digital Library of Periodicals of National Academy of Sciences of Ukraine |
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English |
| topic |
Физика и технология конструкционных материалов Физика и технология конструкционных материалов |
| spellingShingle |
Физика и технология конструкционных материалов Физика и технология конструкционных материалов Levenets, V. Omelnik, O. Shchur, A. XRF with a primary X-rays from the target with monoisotopical surface layer Вопросы атомной науки и техники |
| description |
The development is presented of X-Rays fluorescence analysis using as primary source proton induced X-Rays emission. It is offered to make primary target as double-layer using as the backing natural intermixture of isotopes, and as the upper layer - an isotope with the highest threshold of (p,n)-reaction for given element. Such target allows to reach lower detection limits by decreasing of background γ-emission from (p,n)-reactions. The making of target from copper, nickel, zirconium, and molybdenum are discussed. The presented approach has been used for elemental analysis of the samples of zirconium compounds and alloys, soils, plants and sediments. |
| format |
Article |
| author |
Levenets, V. Omelnik, O. Shchur, A. |
| author_facet |
Levenets, V. Omelnik, O. Shchur, A. |
| author_sort |
Levenets, V. |
| title |
XRF with a primary X-rays from the target with monoisotopical surface layer |
| title_short |
XRF with a primary X-rays from the target with monoisotopical surface layer |
| title_full |
XRF with a primary X-rays from the target with monoisotopical surface layer |
| title_fullStr |
XRF with a primary X-rays from the target with monoisotopical surface layer |
| title_full_unstemmed |
XRF with a primary X-rays from the target with monoisotopical surface layer |
| title_sort |
xrf with a primary x-rays from the target with monoisotopical surface layer |
| publisher |
Національний науковий центр «Харківський фізико-технічний інститут» НАН України |
| publishDate |
2016 |
| topic_facet |
Физика и технология конструкционных материалов |
| url |
http://dspace.nbuv.gov.ua/handle/123456789/111742 |
| citation_txt |
XRF with a primary X-rays from the target with monoisotopical surface layer / V. Levenets, O. Omelnik, A. Shchur // Вопросы атомной науки и техники. — 2016. — № 1. — С. 99-101. — Бібліогр.: 3 назв. — англ. |
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Вопросы атомной науки и техники |
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2025-07-08T02:37:00Z |
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ISSN 1562-6016. PASТ. 2016. №1(101), p. 99-101.
UDC 539.534.9/535-34/539.17+543.4
XRF WITH A PRIMARY X-RAYS FROM THE TARGET WITH
MONOISOTOPICAL SURFACE LAYER
V. Levenets, O. Omelnik, A. Shchur
National Science Center “Kharkov Institute of Physic and Technology”, Kharkov, Ukraine
E-mail: levenets@kipt.kharkov.ua
The development is presented of X-Rays fluorescence analysis using as primary source proton induced X-Rays
emission. It is offered to make primary target as double-layer using as the backing natural intermixture of isotopes,
and as the upper layer an isotope with the highest threshold of (p,n)-reaction for given element. Such target allows
to reach lower detection limits by decreasing of background -emission from (p,n)-reactions. The making of target
from copper, nickel, zirconium, and molybdenum are discussed. The presented approach has been used for
elemental analysis of the samples of zirconium compounds and alloys, soils, plants and sediments.
INTRODUCTION
Nuclear-physical methods of analysis of substances
elemental content using charged particles beams from
electrostatic accelerators are applied to the solution of
the number of analytical problems from metallurgy up
to medicine and ecology. The methods using charged
particles, elastic scattering under back angles (RBS),
charged particles and -emission from nuclear reactions
(NRA), charged particles induced characteristic X-Rays
emission (PIXE) are most spread. This methods use for
initiation of analytical radiation immediately beams of
particles, but indirect mechanism of excitation are
mostly available for solution of some problems. In
particular, PIXE induced XRF, using a suitable target-
converter as primary fluorescence source may be
applied to analyze the samples without sufficient heat
and radiation damages [1, 2]. A similar indirect
mechanism of excitation X-Rays emission was used in
the presented work. The method based on the excitation
of a secondary X-Rays fluorescence by a characteristic
X-Rays from a target-converter for analysis of ZrF4,
HfF4, and ZrCl4 is presented and the possibility to
reduce a contribution to background component of the
continuum bremsstrahlung radiation and gamma
emission from nuclear reactions are also considered.
METHOD
The scheme of analysis using PIXE induced XRF is
shown on Fig. 1. The set-up includes charged particles
accelerator – 1, a primary target – 2, the analyzed
sample – 3 and X-Rays detector – 4.
Accelerator Primary target
1
2
3
Sample analyzed
4
X-Rays detector
Fig. 1. The set-up for PIXE induced XRF analysis
As the material for a target-converter the element is
selected on such a way that characteristic X-Rays have
energy, sufficient to excite fluorescence radiation of
elements of interest in the sample. The experimental set-
up of the technique works as follows. A primary X-Rays
emission is generated under irradiation of a target-
converter by the charged particle beam, for example
protons. This primary emission is used to induce in the
analyzed sample secondary fluorescence X-Rays, which
are the registered by the detector.
Together with characteristic X-Ray radiation the
bremsstrahlung radiation and -radiation from nuclear
reactions are induced due to interaction of protons with
a target-converter matter. The (p,n)-reactions inducing
neutrons give basic contribution in this background. The
relation between intensity of characteristic and
background emission, finally, defines limit of detection.
At increasing of protons energy the intensity of
characteristic X-Rays of target-converter increases
proportionally to 3…4 power of energy and
bremsstrahlung radiation intensity increases too.
Intensity of a background radiation due to the
contribution of -radiation from nuclear reactions at
proton energies below a threshold for nuclear reactions
(p,n)-type is negligible small, and at energies above a
threshold this quantity increases sharply and gives basic
contribution to the background.
As a result of nuclear reactions -quanta with
energies from some tens keV up to several MeV, and
also particles are emitted. This primary radiation as
result of its scattering in the converter, the sample and
details of accelerator produces continuous background
of electromagnetic radiation, including that with energy
in the range of a characteristic X-Rays emission of K-
and L-series of analyzed elements in the sample. The
threshold energies for nuclear reactions are different for
various isotopes of the same element. Therefore the
converter is made from isotope with highest thresholds.
To preferential cost of target it can be made as a double-
layer. Thus thickness of the monoisotopical layer must
be chosen such that it is sufficient for decreasing of
energy of charged particles up to quantity below a
threshold of nuclear reaction (p,n)-type for a material of
the second layer. The second layer may be made from
the chemical element chosen for a primary target with
natural isotopic content. The scheme of a double-layer
primary target is given on Fig. 2, where 5 denotes the
first monoisotopical layer of primary target and 6 the
backing made from substance with a natural isotopic
composition.
B
acking w
ith natural
abundance
M
onoisotopical layer
Protons beam
C
h
a
ra
c
te
ri
st
ic
X
-r
a
y
s
a
n
d
b
a
c
k
g
ro
u
n
d
g
a
m
m
a
-e
m
is
si
o
n
5
6
Fig. 2. Scheme of a primary target
EXPERIMENT
Let's view a case with proton energies 2, 3, and
4 MeV and a target-converter, made from copper, with
natural isotopic composition containing 69.1% of
isotope
63
Cu and 30.9% of isotope
65
Cu. Thresholds of
(p,n)-type reactions for isotopes
63
Cu and
65
Cu are equal
to 4.1 and 2.1 MeV accordingly. Clearly, at energy of
protons 2 MeV it is possible to use copper in a natural
isotopic composition, but for 3 and 4 MeV it is letter to
use isotope
63
Cu. Whereas ranges of protons with
energies of 2.1, 3 and 4 MeV in copper are equal 19.75,
34.23 and 53.96 m (SRIM 2006), thickness of a target-
converter from isotope
63
Cu should be not less than
16 m for protons with energy 3 MeV and 35 m for
protons with energy 4 MeV. If available accelerator can
provide higher energies of protons, and magnitude of
energy of primary X-Rays is not so critical, what is
valid for the majority of practical problems, it is
possible to use a target-converter made of isotopes of
nickel,
58
Ni and
60
Ni, with nickel abundances of 67.9
and 26.2%, and with thresholds for (p,n)-reactions 9.3
and 6.9 MeV.
Let energy of primary X-Rays in the range of
15...18 keV is required for the analysis. This energy
diapason corresponds to X-Rays К-serie elements Zr
and Мо, and it is preferable to make the target-converter
from the isotopes
90
Zr,
92
Mo or
94
Mo. The choice of an
isotope for the upper layer of the converter is similar
featured above. Thickness of the upper layer is chosen
such that energy of protons on an exit from it was less
than the threshold energy of (p,n)-reaction for isotopes
in the inferior layer, and thus interaction of protons with
a material of the inferior layer, is similar to interaction
with a material of the upper layer, i. e. there is low
probably for nuclear reactions. The required thicknesses
of the upper monoisotopical layer may be up to some
tens microns on the average and they change for
discussed above elements of target-converter in
dependence on choice of element and energy of protons.
Thickness of the inferior layer which is made from a
material of a natural isotopic composition, must be
chosen such that to provide sufficient hardness of target-
converter.
The set of converters enumerated above, allows to
carry out determination of elements in a range up to
Z = 39 on K-series, and elements with Z > 50 on
L-series. The offered approach has been used by authors
for determination of elements from Ca to Mo, hafnium,
tungsten and lead in samples of zirconium and hafnium
compounds and alloys, soils, plants and sediments. The
use of converters with the offered structure, has allowed
to reach lower limits of detection of elements, to raise
expressivity of the analysis, to preference analysis cost.
CONCLUSION
The application of a target-converter allows to
reduce the component of background caused by (p, n)-
nuclear reactions when using charged particles with
energy above the nuclear reaction thresholds. This
approach allows to use higher energy of beam particles,
and accordingly to increase the intensity of a primary
X-Ray fluorescence, to reduce detection limits of
elements in analyzed sample and to improve the
analysis be lowering of spectrum measurement time at
the same sensitivity.
REFERENCES
1. K. Jinno, K. Kawasaki, M. Sato, et al. // J. Rad.
Chem. 1983, v. 76, N 1, p. 139-149.
2. O.I. Ehichev, V.V. Levenets, N.F. Severin,
A.I. Chumachenko, A.A. Shchur // Proceedings of the V
All-Union meeting on application of charged particle
accelerators in a national economy. М.: “Science”,
1985, p. 147.
3. A.G. Karydas, M. Budnar, Z. Smit, C. Zarkadas,
T. Paradellis. Proton induced monochromatic X-ray
beams: A versatile source for resonant Raman scattering
studies // Nucl. Instr. &Meth. 2002, B189. N 1-4,
p. 43-48.
Статья поступила в редакцию 19.08.2015 г.
РЕНТГЕНОФЛУОРЕСЦЕНТНЫЙ АНАЛИЗ С ВОЗБУЖДЕНИЕМ ПЕРВИЧНОГО
РЕНТГЕНОВСКОГО ИЗЛУЧЕНИЯ ЗАРЯЖЕННЫМИ ЧАСТИЦАМИ В МИШЕНИ
С МОНОИЗОТОПНЫМ ПОВЕРХНОСТНЫМ СЛОЕМ
В. Левенец, А. Омельник, А. Щур
Представлена модификация рентгенофлуоресцентного анализа, использующего как источник
флуоресценции рентгеновское излучение, возбуждаемое протонами. Предложено использовать первичную
мишень с моноизотопным поверхностным слоем и подложкой из того же вещества с естественным
изотопным составом. Для изготовления верхнего слоя используется изотоп с наибольшим порогом реакции
(p,n)-типа. Такая мишень позволяет снизить пределы обнаружения при элементном анализе за счет
уменьшения фонового -излучения из реакций (p,n)-типа. Обсуждена возможность изготовления первичных
мишеней из никеля, меди, циркония и молибдена. Представленный подход использован для элементного
анализа образцов из соединений и сплавов циркония, почв, растений и донных отложений.
РЕНТГЕНОФЛУОРЕСЦЕНТНИЙ АНАЛІЗ ЗІ ЗБУДЖЕННЯМ ПЕРВИННОГО
РЕНТГЕНІВСЬКОГО ВИПРОМІНЮВАННЯ ЗАРЯДЖЕНИМИ ЧАСТИНКАМИ
В МІШЕНІ З МОНОІЗОТОПНИМ ПОВЕРХНЕВИМ ШАРОМ
В. Левенець, О. Омельник, А. Щур
Представлена модифікація рентгенофлуоресцентного аналізу з використанням в якості джерела
флуоресценції рентгенівське випромінювання, що збуджуване протонами. Запропоновано використовувати
первинну мішень з моноізотопним поверхневим шаром і підкладкою з тієї ж речовини з природним вмістом
ізотопів. Для виготовлення поверхневого шару використовується ізотоп з найбільшим порогом реакції (p,n)-
типу. Така мішень дає змогу знизити границі визначення при елементному аналізі за рахунок зменшення
фонового -випромінювання з реакцій (p,n)-типу. Обговорено можливість виготовлення первинних мішеней
з нікелю, меді, цирконію та молібдену. Запропонований підхід використано для елементного аналізу зразків
із сполук та сплавів цирконію, ґрунтів, рослин, донних відкладень.
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