The research of X-ray and gamma radiation absorption by layered structures
Исследуется прохождение рентгеновского и гамма-излучений через сборки, состоящие из слоѐв материалов с различными атомными номерами. Экспериментально измерены и рассчитаны в GEANT спектры излучения, прошедшего через сборку. Использовались различные спектры падающего излучения (в экспериментах источн...
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Deiev, O.S. Mazilov, A.A. Mazilov, A.V. Maslov, N.I. Shulika, M.Yu. 2017-04-04T06:06:01Z 2017-04-04T06:06:01Z 2016 The research of X-ray and gamma radiation absorption by layered structures / O.S. Deiev, A.A. Mazilov, A.V. Mazilov, N.I. Maslov, M.Yu. Shulika // Вопросы атомной науки и техники. — 2016. — № 3. — С. 105-110. — Бібліогр.: 13 назв. — англ. 1562-6016 PACS: 07.85.Fv, 61.80.Cb https://nasplib.isofts.kiev.ua/handle/123456789/115399 Исследуется прохождение рентгеновского и гамма-излучений через сборки, состоящие из слоѐв материалов с различными атомными номерами. Экспериментально измерены и рассчитаны в GEANT спектры излучения, прошедшего через сборку. Использовались различные спектры падающего излучения (в экспериментах источники излучения ²⁴¹Am, ⁵⁷Co, ¹³⁷Cs, ⁶⁰Co), а также комбинации материалов с различными атомными номерами и толщинами. Определены коэффициенты КS и КЕ, характеризующие прохождение частиц через гетерогенные слои. КS и КЕ меняют знак с увеличением энергии квантов и растут с увеличением толщины пластин. It is investigated the passage of X-ray and gamma radiation through assembly consisting of layers of materials with different atomic numbers. It was experimentally measured and calculated in GEANT the spectra of radiation, passed through the assembly. Various spectra of the incident radiation (in experiments, the radiation sources ²⁴¹Am, ⁵⁷Co, ¹³⁷Cs, ⁶⁰Co), as well as combinations of materials with different atomic numbers and thicknesses were used. Coefficients of КS and КЕ that characterize the passage of particles through heterogeneous layers were defined. КS and КЕ change sign with increasing of photon energy and growth with increase of the plates thickness. Досліджується проходження рентгенівського і гамма-випромінювань через зборки, що складаються із шарів матеріалів з різними атомними номерами. Експериментально виміряні і розраховані в GEANT спектри випромінювання, що пройшло через зборку. Використовувалися різні спектри падаючого випромінювання (в експериментах джерела випромінювання ²⁴¹Am, ⁵⁷Co, ¹³⁷Cs, ⁶⁰Co), а також комбінації матеріалів з різними атомними номерами й товщинами. Визначено коефіцієнти КS і КЕ, що характеризують проходження часток через гетерогенні шари. КS і КЕ міняють знак зі збільшенням енергії квантів і ростуть зі збільшенням товщини пластин. The Russian Science Foundation (project № 15-12-10019) supported this work. en Національний науковий центр «Харківський фізико-технічний інститут» НАН України Вопросы атомной науки и техники Детекторы и детектирование ядерных излучений The research of X-ray and gamma radiation absorption by layered structures Исследование поглощения рентгеновского и гамма-излучений слоистыми структурами Дослідження поглинання рентгенівського і гамма-випромінювань шаруватими структурами Article published earlier |
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Digital Library of Periodicals of National Academy of Sciences of Ukraine |
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| title |
The research of X-ray and gamma radiation absorption by layered structures |
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The research of X-ray and gamma radiation absorption by layered structures Deiev, O.S. Mazilov, A.A. Mazilov, A.V. Maslov, N.I. Shulika, M.Yu. Детекторы и детектирование ядерных излучений |
| title_short |
The research of X-ray and gamma radiation absorption by layered structures |
| title_full |
The research of X-ray and gamma radiation absorption by layered structures |
| title_fullStr |
The research of X-ray and gamma radiation absorption by layered structures |
| title_full_unstemmed |
The research of X-ray and gamma radiation absorption by layered structures |
| title_sort |
research of x-ray and gamma radiation absorption by layered structures |
| author |
Deiev, O.S. Mazilov, A.A. Mazilov, A.V. Maslov, N.I. Shulika, M.Yu. |
| author_facet |
Deiev, O.S. Mazilov, A.A. Mazilov, A.V. Maslov, N.I. Shulika, M.Yu. |
| topic |
Детекторы и детектирование ядерных излучений |
| topic_facet |
Детекторы и детектирование ядерных излучений |
| publishDate |
2016 |
| language |
English |
| container_title |
Вопросы атомной науки и техники |
| publisher |
Національний науковий центр «Харківський фізико-технічний інститут» НАН України |
| format |
Article |
| title_alt |
Исследование поглощения рентгеновского и гамма-излучений слоистыми структурами Дослідження поглинання рентгенівського і гамма-випромінювань шаруватими структурами |
| description |
Исследуется прохождение рентгеновского и гамма-излучений через сборки, состоящие из слоѐв материалов с различными атомными номерами. Экспериментально измерены и рассчитаны в GEANT спектры излучения, прошедшего через сборку. Использовались различные спектры падающего излучения (в экспериментах источники излучения ²⁴¹Am,
⁵⁷Co,
¹³⁷Cs,
⁶⁰Co), а также комбинации материалов с различными атомными
номерами и толщинами. Определены коэффициенты КS и КЕ, характеризующие прохождение частиц через
гетерогенные слои. КS и КЕ меняют знак с увеличением энергии квантов и растут с увеличением толщины
пластин.
It is investigated the passage of X-ray and gamma radiation through assembly consisting of layers of materials
with different atomic numbers. It was experimentally measured and calculated in GEANT the spectra of radiation,
passed through the assembly. Various spectra of the incident radiation (in experiments, the radiation sources ²⁴¹Am, ⁵⁷Co, ¹³⁷Cs, ⁶⁰Co), as well as combinations of materials with different atomic numbers and thicknesses were used.
Coefficients of КS and КЕ that characterize the passage of particles through heterogeneous layers were defined. КS
and КЕ change sign with increasing of photon energy and growth with increase of the plates thickness.
Досліджується проходження рентгенівського і гамма-випромінювань через зборки, що складаються із
шарів матеріалів з різними атомними номерами. Експериментально виміряні і розраховані в GEANT спектри
випромінювання, що пройшло через зборку. Використовувалися різні спектри падаючого випромінювання
(в експериментах джерела випромінювання ²⁴¹Am, ⁵⁷Co, ¹³⁷Cs, ⁶⁰Co), а також комбінації матеріалів з різними
атомними номерами й товщинами. Визначено коефіцієнти КS і КЕ, що характеризують проходження часток
через гетерогенні шари. КS і КЕ міняють знак зі збільшенням енергії квантів і ростуть зі збільшенням товщини пластин.
|
| issn |
1562-6016 |
| url |
https://nasplib.isofts.kiev.ua/handle/123456789/115399 |
| citation_txt |
The research of X-ray and gamma radiation absorption by layered structures / O.S. Deiev, A.A. Mazilov, A.V. Mazilov, N.I. Maslov, M.Yu. Shulika // Вопросы атомной науки и техники. — 2016. — № 3. — С. 105-110. — Бібліогр.: 13 назв. — англ. |
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ISSN 1562-6016. ВАНТ. 2016. №3(103) 105
THE RESEARCH OF X-RAY AND GAMMA RADIATION ABSORPTION
BY LAYERED STRUCTURES
O.S. Deiev
1
, A.A. Mazilov
1,2
, A.V. Mazilov
1
, N.I. Maslov
1
, M.Yu. Shulika
1
1
National Science Center “Kharkov Institute of Physics and Technology”, Kharkov, Ukraine;
2
Belgorod State University, Belgorod, Russia
It is investigated the passage of X-ray and gamma radiation through assembly consisting of layers of materials
with different atomic numbers. It was experimentally measured and calculated in GEANT the spectra of radiation,
passed through the assembly. Various spectra of the incident radiation (in experiments, the radiation sources 241Am,
57Co, 137Cs, 60Co), as well as combinations of materials with different atomic numbers and thicknesses were used.
Coefficients of КS and КЕ that characterize the passage of particles through heterogeneous layers were defined. КS
and КЕ change sign with increasing of photon energy and growth with increase of the plates thickness.
PACS: 07.85.Fv, 61.80.Cb
INTRODUCTION
Search of the materials that provide effective protec-
tion against ionizing radiation remains a topical area of
radiation physics [1 - 5]. Protection of nuclear power
plants, reactors and tanks for spent nuclear fuel, neutron
sources, electron accelerators – traditional use of biolog-
ical protection [2, 4]. In nuclear medicine the protection
is necessary when working with highly active radioiso-
topes as at the stage of pharmaceuticals preparation, as
in the process of medical procedures conducting [6].
Typically, this problem is solved by “force method” –
by increasing of the protective layer thickness to a value
that provides an acceptable dose to personnel. However,
effective protection of electronics, instruments and de-
tectors is particularly relevant in the space industry,
where criterion of weight minimizing and size protec-
tion is important.
In most practical tasks the radiation protection of
nuclear facilities is a heterogeneous mixture of different
environments. Also multilayer protective systems are
applied in engineering of screening devices for various
types of detectors, for example, their collimating systems.
The calculation of such protection by analytical
methods is quite difficult because the buildup factors of
heterogeneous environments depend on a large number
of parameters of the task: energy of gamma radiation,
thickness, material, quantity and geometry of the layers
and their relative position. In works [3 - 5] the main
regularities of buildup factors formation were described
and a number of formulas for mathematical calculation
were proposed. It is shown that the efficiency of protec-
tion against gamma radiation by a heterogeneous as-
sembly is better in case when the light material facing to
the source. However, obviously, these formulas cannot
take into account the variety of practical problems of
building and calculation of multilayer defenses. In such
cases it is necessary to use computer simulation meth-
ods. Now for the computer simulation of radiation pas-
sage through heterogeneous media, various computer
codes are widely used. In particular GEANT 3 and
GEANT 4 [9] offer an adequate and comprehensive
simulation of all physical processes of ionizing radiation
interaction with the material, taking into account the
geometry and elemental composition of protection.
The purpose of this work is the numerical descrip-
tion and experimental measurement of the spectral and
dosimeter characteristics of the radiation passed through
pairwise interchanged layers of materials with different
nuclear charges Z, and thickness. The values of coeffi-
cients determining the noncommutativeness of the quan-
ta passing through the heterogeneous layers were meas-
ured and calculated.
We refused to test the repeated two-layer periodic
structures, as in [7, 8] it is shown that the effect of
commutativity decreases, and the overall weakening
tends to value in a homogeneous medium with averaged
Z. Conversely, in the experiments and calculations we
have focused on increasing of the materials thicknesses.
1. EXPERIMENTAL TECHNIQUE
AND COMPUTER MODEL
There were used designed and manufactured in NSC
KIPT sealed modules of two types: non-cooled silicon
PIN detector and the detection system scintillator
CsI(Tl) – silicon PIN photodiode [10, 11]. These mod-
ules and readout electronics showed high stability when
used in nuclear physics experiments, in control device
of element concentrations in medical diagnostic devices
[12], spectrometry and dosimetry [13].
The energy range of incident γ-rays was
10 keV…1.33 MeV (the radiation sources 241Am, 57Co,
137Cs, 60Co). Radiation with energy of 5…150 keV for
Si detector and 35…1500 keV for the system scintilla-
tor-photodiode was registered.
Between the radiation source and the detector two
plates of different materials were placed, the spectra of
the passed radiation while changing the order of plates
were measured.
The attenuation of gamma radiation when passing
through protection, consisting of alternating materials
layers, depends ceteris paribus on the gamma radiation
energy Еγ and the materials protection thicknesses.
Using the software package GEANT 3.21, it was
simulated the assembly, consisting of a point source of
γ-quanta, of light and heavy metal plates and the total
absorption detector. The scheme of experiments is
shown on Fig. 1.
a b
Fig. 1. Schema of computer model
ISSN 1562-6016. ВАНТ. 2016. №3(103) 106
The quanta from source, passing a heterogeneous
target, enter the detector, which records the number of
particles and their total remaining energy. It was simu-
lated as a discrete photon energies as an energy spectra.
The assembly was located in the air. The detector was
close to the last plate.
On Fig. 2 it is shown a visual representation in
GEANT 4 [7] of the trajectories of X-rays and gamma
quanta (green line) for the system Al-Pb (a) and Pb-Al
(b). The layers of material are changed places, and radi-
ation that passes into the forward hemisphere is detect-
ed.
a b
Al-Pb Pb-Al
Fig. 2. Visual representation in GEANT 4 of the trajec-
tories of X-rays and γ-quanta (green line) for the system
Al-Pb (a) and Pb-Al (b). The layers of material
are changed places, and radiation that passes into the
forward hemisphere is detected (blue sphere-counter).
Green sphere-counter registers electrons
The aim of computer simulation was to determine
the radiation protection efficiency in case of the se-
quence of materials location: light to source and heavy
to source.
2. RESULTS AND DISCUSSION
Hereinafter, the material on the left (written in text as
a part of the pair), is faced to the radiation source, both in
calculations and in experiments. For example, writing
1.2 mm Fe-0.3 mm Pb means the arrangement of objects
in the following way: radiation source – first foil
1.2 mm Fe – second foil 0.3 mm Pb – Si or CsI detector
(in experiment) or counter quanta (in calculations).
Let, SLH is a count of quanta Nγ recorded by the de-
tector, and ЕLH, MeV – total energy Nγ(Еγ)∙Еγ, in case of
location "Source → light material (L) → heavy material
(H) → detector" and SHL, ЕHL – in case of location
"Source → heavy material (H) → light material (L)
→detector". In the experiment and calculations the var-
ious sizes, possessing noncommutative feature, are
compared. Let us introduce the coefficients of the dif-
ferences in the passage КS , КЕ:
КS = (SHL / SLH -1)·100%, (1)
КЕ = (ЕHL / ЕLH -1)·100%. (2)
If the coefficients are greater than zero, then the pro-
tection efficiency light material heavy material (LH)
above. If less than zero, the protection efficiency of HL
above.
2.1. COMPUTER SIMULATION RESULTS
Using the software package GEANT 3.21, computer
simulation for studying the γ-radiation passage through
a combination of tungsten and aluminum foils, in analo-
gy to [7, 8], was carried out. The simulation results are
shown on Fig. 3.
Fig. 3. The change of KE depending on the thickness
of tungsten and the energy of incident radiation
For thicknesses of Al-4.8 mm and W-0.3 mm in the
energy range of incident radiation from 50 to 400 keV
(with exception of 70…100 keV) КS > 0 and KE > 0 for
1…6%, that shows a better protection in case of materi-
als location of light to source.
At the energy range 70…100 keV the opposite effect
(noncommutativeness changes sign) is occur. It is con-
nected with generation of characteristic X-ray (CXR) in
tungsten. K-absorption edge for tungsten is 69.524 keV.
By increasing the thickness of tungsten up to 0.6 mm,
the influence of CXR on the commutatively value de-
creases, and while increasing up to 1 mm, the influence
of CXR disappears.
Also with the help of the software package
GEANT 3.21 the passage of γ-radiation through a com-
bination of lead and aluminum foils was studied. The
scheme of experiment is shown on Fig. 1, where the
light material is taken as aluminum, and heavy as lead.
The results of computer simulation for different ma-
terials thicknesses and energies of incident radiation are
presented on Fig. 4,a,b.
a
b
Fig. 4. The change of KE depending on lead and alumi-
num thicknesses and energy of the incident radiation
ISSN 1562-6016. ВАНТ. 2016. №3(103) 107
For these calculations the effect of commutativeness
sign changing by generating of lead CXR (K absorption
edge 88.006 keV) is also occurred.
The presented data of computer simulation of gam-
ma radiation passage through heterogeneous protection
system show that multi-layer protection is more effi-
cient in case when the light material facing to the
source, as theoretically predicted. The effect can reach
5…25% depending on the energy of incident radiation
and combinations of thicknesses of protective materials.
However, at energies of incident radiation close to
the energy of K absorption edge for heavy material the
opposite effect with a change of commutativity sign can
be occurred, and it is more significant for thin plates.
Typical results of calculations in GEANT 4 are pre-
sented on Fig. 5,a-c.
a
Eγ = 60 keV
b
Eγ = 122 keV
с
Eγ = 662 keV
Fig. 5. The calculated energy distributions
of quanta, depending on the energy of incident radiation
for a pair of Pb-Al
Some numerical values КS and КЕ are given in Ta-
ble 1. Note the change of noncommutativeness sign and
its growth with increasing of the plates thickness at a
fixed value of the quanta energy.
Table 1
The numerical values КS and КЕ, %
Eγ, keV
Plates combination,
mm
КS, % КЕ, %
60 Pb 0.3-Al 4 -12.8 -11.83
122 Pb 0.3-Fe 3 -13.71 -7.9
122 Pb 0.6-Fe 6 -22.6 -16.6
122 Pb 0.9-Fe 9 -34.8 -23.22
122 Pb 0.3-Al 4 -5.9 -5.15
490 Pb 0.3-Al 4 0.43 3.07
662 Al 4-Pb 0.3 0.2 0.1
662 Al 8-Pb 0.6 0.9 0.4
662 Al 24-Pb 1.8 6.4 3
662 Al 48-Pb 3.6 13.5 6.81
662 Al 96-Pb 7.2 77.1 32.1
662 Al 120-Pb 9 101.5 43
662 Al 172-Pb 13 156.3 67.14
2 000 Al 4-Pb 0.3 0.18 0.04
2 000 Al 96-Pb 7.2 8.48 1.67
2 000 Al 116-Pb-8.6 26.83 5.14
2 000 Al 126-Pb 9.4 28.76 5.92
2 000 Al 140-Pb 10.4 29.36 5.83
2 000 Al 160-Pb 11.9 30.61 6.42
3 000 Pb 7.2-Al 96 6.2 0.
3 000 Al 160-Pb 11.9 19.49 1.55
5 000 Al 96-Pb 7.2 3.9 -0.8
5 000 Al 160-Pb 11.9 11.08 -1.3
100 000 Al 160-Pb 11.9 1.54 -1.27
100 000 Al 200-Pb 20 6.1 1.1
200 000 Al 200-Pb 20 0.47 9.3
In Table 2 the calculations for КS, and КЕ and Eγ =
662 keV are given, and the quanta percentage N662/N0
passed a couple of plates without interaction is present-
ed. The thickness of the lead plate is constant, and the
thickness of Al is increased.
There is an increase of noncommutativeness effect
with increasing of Al thickness, which correlates with
the decrease of N662/N0. Accordingly, a greater propor-
tion of quanta dissipated, that causes the increase of
noncommutativeness.
Table 2
The numerical values of КS, КЕ, N662/N0
Plates combination,
mm
КS, % КЕ, % N662/N0
Pb 12-Al 6 4.6 2.5 0.216
Pb 12-Al 12 10.46 5.84 0.192
Pb 12-Al 24 21.87 11.1 0.15
Pb 12-Al 48 47.64 23.06 0.092
Pb 12-Al 96 96.05 44.6 0.035
Pb 12-Al 120 112.6 49.1 0.022
Pb 12-Al 160 141.2 59.3 0.01
The calculations of gamma-rays passage through the
layers of materials were carried out and КS and КЕ for
the quanta spectrum of ~ 1/Еγ were counted. On
Figs. 6, 7 the calculated spectra of the incident quanta
and quanta passed through a couple of plates are shown.
ISSN 1562-6016. ВАНТ. 2016. №3(103) 108
Fig. 6. Calculated energy distributions of passed gam-
ma-ray for pairs Pb-Fe, and the spectrum
of incident quanta ~1/Еγ (0…1 MeV)
Fig. 7. Calculated energy distributions of passed gam-
ma-ray for pairs Pb-Fe, and the spectrum
of incident quanta ~1/Еγ (0…10 MeV)
The numerical values of КS, КЕ for gamma-quanta
spectrum ~1/Еγ are shown in Table 3.
Table 3
The numerical values of КS, КЕ for the quanta
spectrum ~1/Еγ
Plates combination,
mm
КS , % КЕ , %
~1/Еγ,
MeV
Pb 2-Fe 10 11.4 5.86 0…1
Pb 2-Fe 10 6.32 0.95 0…5
Pb 2-Fe 10 5.5 0.25 0…10
Pb 10-Fe 40 8.6 3.6 0…100
Pb 20-Fe 80 10.76 3.0 0…100
Pb 30-Fe 100 5.56 7.52 0…100
2.2. EXPERIMENTAL RESULTS
Radiation sources 241Am, 57Co, 137Cs, 60Co were used,
the energy range for gamma-rays was 0.06…1.33 MeV.
Experimental spectra of radiation passed through a plate
pair were measured and КS value was evaluated.
Note that within the experiment precision the peaks
of total absorption in the calculations and in the experi-
ment are equal. On Fig. 8 it is shown the experimental
energy spectra of quanta for the radiation source 241Am
and a pair Pb-Al, measured by Si-detector. In the left
part of the spectrum in case of location pairs Al-Pb by
solid material to the detector appears L triplet of Pb
CXR (see Fig. 8,a). In this experiment it is significantly
influence the lead CXR on the КS value. Moreover, the
КS value changes sign.
a
Al 5.8 mm - Pb 0.3 mm
b
Pb 0.3 mm - Al 5.8 mm
Fig. 8. Experimental energy distributions of quanta
for radiation source 241Am and the pair Pb-Al measured
by Si-detector
On Fig. 9 it is shown the experimental energy spec-
tra of quanta for the radiation source 241Am and a pair
Pb-Fe, measured by the CsI-detector.
Fig. 9. Experimental energy distribution of quanta
for radiation source 57Со and the pair Pb-Fe measured
by CsI-detector
For pair Pb 0.3 mm and Fe 2.55 mm and the energy
Еγ =122 keV we have КS = (SHL/SLH -1)·100% = -10.5%.
In this experiment it is significantly influence of lead
CXR on КS value, and there is a difference – additional
peak in the left part of the spectrum (channels
600…800).
On Fig. 10 it is shown the experimental energy spec-
tra of quanta for the radiation source 137Сs and a pair
Pb-Fe, measured by CsI detector. In these experiments,
Compton scattering of quanta on КS value is essentially,
and there is a distinction on the left part of the spectra.
ISSN 1562-6016. ВАНТ. 2016. №3(103) 109
a
Pb 10 mm - Fe 8 mm
b
Pb 1.2 mm - Fe 12 mm
c
Pb 10 mm - Fe 52 mm
Fig. 10. Experimental energy distribution of quanta
for radiation source 137Сs and pairs Pb-Fe, measured
by CsI-detector
On Fig. 11 it is shown the experimental energy spec-
tra of quanta for radiation source 60Со and a pair of Pb-
Fe, measured by the CsI-detector. The experimental
results are shown in Table 4.
a
Without plates
b
Pb 1.8 mm - Fe 10 mm
Fig. 11. Experimental energy distribution of quanta
for radiation source 60Co and the pair of Pb-Fe,
measured by the CsI-detector
Table 4
Experimental values КS
Radiation
source
Plates combination,
mm
КS ,%
241Аm 1 Cu - 0.3 Pb -0.5
241Аm 1.2 Fe - 0.3 Pb -6.28
241Аm 2 Fe - 0.3 Pb -9.5
241Аm 4 Al - 0.3 Pb -3.8
241Аm 5.8 Al - 0.3 Pb -7.3
Co57 0.3 Pb - Fe 2.55 -10.5
137Сs 0.3 Pb - 1 Cu 0.7
137Сs 1.2 Pb - 12 Fe 25.4
137Сs 10 Pb - 8 Fe 29.9
137Сs 10 Pb - 52 Fe 113.7
137Сs 40 Pb - 52 Fe 49.8
60Co 1.8 Pb - Fe 10 20.0
As experiment showed a sign of noncommu-
tativeness is changed with increasing of photon energy
and the plate thickness. This coincides with the data of
calculations in GEANT 4 and GEANT 3.
CONCLUSIONS
The passage of X-ray and gamma radiation through
assembly consisting of layers of materials with different
atomic numbers was investigated. It was experimentally
measured and calculated in GEANT the spectra of ra-
diation, passed through the assembly. The various spec-
tra of incident radiation (in experiments, the radiation
sources 241Am, 57Co, 137Cs, 60Co), as well as combina-
tions of materials with different atomic numbers and
thicknesses were used.
Coefficients КS and КЕ that characterize the passage
of particles through heterogeneous layers were defined.
КS and КЕ change sign with increasing of photon energy
and growth with increase of the plates thickness.
The physical causes of the observed commutatively
were determined. It occurs only via secondary process-
es: Compton scattering, photoelectric effect, electron-
positron pairs production. Thus, the effect size growthes
with the thickness increas.
The data of computer simulation of the gamma radi-
ation passage through heterogeneous protection system
show that multi-layer protection, usually effective in
ISSN 1562-6016. ВАНТ. 2016. №3(103) 110
case of arrangement of a light material to the radiation
source.
At the incident X-ray radiation energies close to the
energy of K-, L-absorption edge for heavy material the
noncommutativeness sign is negative and the inverse
effect is observed, so in such situation more effective
protection is in case of a heavy material location to the
radiation source. This effect is most significant for thin
foils (~1 mm).
The Russian Science Foundation (project № 15-12-
10019) supported this work.
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Article received 14.01.2016
ИССЛЕДОВАНИЕ ПОГЛОЩЕНИЯ РЕНТГЕНОВСКОГО И ГАММА-ИЗЛУЧЕНИЙ
СЛОИСТЫМИ СТРУКТУРАМИ
А.С. Деев, А.А. Мазилов, А.В. Мазилов, Н.И. Маслов, М.Ю. Шулика
Исследуется прохождение рентгеновского и гамма-излучений через сборки, состоящие из слоѐв материа-
лов с различными атомными номерами. Экспериментально измерены и рассчитаны в GEANT спектры излу-
чения, прошедшего через сборку. Использовались различные спектры падающего излучения (в эксперимен-
тах источники излучения 241Am, 57Co, 137Cs, 60Co), а также комбинации материалов с различными атомными
номерами и толщинами. Определены коэффициенты КS и КЕ, характеризующие прохождение частиц через
гетерогенные слои. КS и КЕ меняют знак с увеличением энергии квантов и растут с увеличением толщины
пластин.
ДОСЛІДЖЕННЯ ПОГЛИНАННЯ РЕНТГЕНІВСЬКОГО І ГАММА-ВИПРОМІНЮВАНЬ
ШАРУВАТИМИ СТРУКТУРАМИ
О.С. Деєв, О.О. Мазілов, О.В. Мазілов, М.І. Маслов, М.Ю. Шуліка
Досліджується проходження рентгенівського і гамма-випромінювань через зборки, що складаються із
шарів матеріалів з різними атомними номерами. Експериментально виміряні і розраховані в GEANT спектри
випромінювання, що пройшло через зборку. Використовувалися різні спектри падаючого випромінювання
(в експериментах джерела випромінювання 241Am, 57Co, 137Cs, 60Co), а також комбінації матеріалів з різними
атомними номерами й товщинами. Визначено коефіцієнти КS і КЕ, що характеризують проходження часток
через гетерогенні шари. КS і КЕ міняють знак зі збільшенням енергії квантів і ростуть зі збільшенням товщи-
ни пластин.
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