Spectra of pyroelectric X-ray generator
The construction of X-ray generator based on a pyroelectric crystal LiNbO₃ is described. Some properties of radiation spectra from the X-ray generator are presented. Measurements of the spectra were performed at heating and cooling of the crystal with copper and chromium targets. The maximum energ...
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| Date: | 2004 |
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Національний науковий центр «Харківський фізико-технічний інститут» НАН України
2004
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| Cite this: | Spectra of pyroelectric X-ray generator / V.I. Nagaychenko, V.M. Sanin, A.M. Yegorov, A.V. Shchagin // Вопросы атомной науки и техники. — 2004. — № 2. — С. 214-216. — Бібліогр.: 11 назв. — англ. |
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Digital Library of Periodicals of National Academy of Sciences of Ukraine| _version_ | 1860233310739890176 |
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| author | Nagaychenko, V.I. Sanin, V.M. Yegorov, A.M. Shchagin, A.V |
| author_facet | Nagaychenko, V.I. Sanin, V.M. Yegorov, A.M. Shchagin, A.V |
| citation_txt | Spectra of pyroelectric X-ray generator / V.I. Nagaychenko, V.M. Sanin, A.M. Yegorov, A.V. Shchagin // Вопросы атомной науки и техники. — 2004. — № 2. — С. 214-216. — Бібліогр.: 11 назв. — англ. |
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| container_title | Вопросы атомной науки и техники |
| description | The construction of X-ray generator based on a pyroelectric crystal LiNbO₃ is described. Some properties of radiation spectra from the X-ray generator are presented. Measurements of the spectra were performed at heating and cooling of the crystal with copper and chromium targets. The maximum energy in the X-ray spectrum versus
crystal temperature is presented.
Описано конструкцію рентгенівського генератора, заснованого на піроелектричному кристалі LiNbO₃.Наведені деякі властивості спектрів випромінювання від рентгенівського генератора. Виміри спектрів були виконані при нагріванні й охолодженні кристалу з мішенями з міді і хрому. Представлено максимальну енергію рентгенівського спектру в залежності від температури кристалу.
Описана конструкция рентгеновского генератора, основанного на пироэлектрическом кристалле LiNbO₃. Представлены некоторые свойства спектров излучения от рентгеновского генератора. Измерения спектров были выполнены при нагревании и охлаждении кристалла с мишенями из меди и хрома. Представлена максимальная энергия рентгеновского спектра в зависимости от температуры кристалла.
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SPECTRA OF PYROELECTRIC X-RAY GENERATOR
V.I. Nagaychenko, V.M. Sanin, A.M. Yegorov, A.V. Shchagin
NSC KIPT, Kharkov 61108, Ukraine
The construction of X-ray generator based on a pyroelectric crystal LiNbO3 is described. Some properties of
radiation spectra from the X-ray generator are presented. Measurements of the spectra were performed at heating
and cooling of the crystal with copper and chromium targets. The maximum energy in the X-ray spectrum versus
crystal temperature is presented.
PACS: 77.70.+a, 07.85.m
INTRODUCTION
The pyroelectric crystals are known to have an
amazing capability for generating electron beams, as
their temperature changes [1-8]. The electron beam
energy can attain 170 keV [7], depending on the type of
crystal, its thickness, heating/cooling conditions. The
electron beam can even be self-focused [8]. The electric
fields generated by pyrocrystals can be as high as
106 V/cm [9]. As it has been recently demonstrated, this
phenomenon can be used for creating a compact low-
power X-ray generator [6,9,10,11]. The basic
peculiarities of this generator are the absence of outer
high-voltage power source, safety, small size
[6,9,10,11]. Here, we present some properties of X-ray
spectra from pyroelectric X-ray generator with copper
and chromium foils.
1. THE X-RAY GENERATOR
Pyroelectric X-ray generator was created at Kharkov
Institute of Physics and Technology. The scheme of the
generator is similar to one described in Refs.
[6,9,10,11]. It is shown in Fig.1.
The generator uses a pyroelectric crystal LiNbO3 of size
3.7x4.3x2.5 mm3, which is subjected to cyclic variations
of temperature (heating/cooling) in the temperature
range from -50°C to +120°C. The Z – axis of the crystal
is along the axis of the generator. A vitrified wire
resistor was used for heating, while liquid nitrogen was
used for cooling. The cooling line was fabricated from
copper rod, and its one end was closely connected with
the crystal and the heater, and the other end was
immersed in liquid nitrogen. The duration of heating
was specified by the resistor current value. The air
pressure in the chamber of the generator can be
regulated with the help of a variable leak valve and a
vacuum pump. The optimum pressure ranges was found
between 10 and 50 mTorr. The grounded metal foil
serve as a target for generation of X-rays. The spacing
between the foil and the crystal surface can be varied
from 0 to 15 mm. The X-ray spectra are measured by a
semiconductor Si(Li) X-ray detector having a resolution
of 250 eV (full width at half height). The brass base and
cooling line and target was grounded.
___________________________________________________________
PROBLEMS OF ATOMIC SIENCE AND TECHNOLOGY. 2004. № 2.
Series: Nuclear Physics Investigations (43), p.214-216. 214
Fig.1. The scheme of the pyroelectric X-ray generator
1 - LiNbO3 crystal, 2 - brass base, 3 - heating/cooling line, 4 – vacuum valve, 5 - Dewar vessel with liquid nitrogen,
6 - vacuum line, 7 - liquid-nitrogen trap, 8 - vacuum connector, 9 – variable leak valve, 10 - vacuum chamber of the
generator, 11 - teflon vacuum obturator of the cooling line, 12 – gas pressure measuring device, 13 - metal foil,
14 - transparent glass window, 15 - resistor-heater, 16 - Si(Li) X-ray detector, 17 - computer, 18 - temperature-
measuring device, 19 - fore-vacuum pump, 20 - pulse-height analyzer, 21 – thermocouple
N2
19
Fore-vacuum
pump
N2
14
3
2
5
6
7
Т0С Power
supply
8
9 10
11
12 13
14
Computer
1615
17
18
20
21
2. X-RAY SPECTRA
The crystal surface on the side of the detector should
be charged positively at heating and negatively at
cooling. So, at cooling, the electrons can go from the
crystal to the target. The target, being bombarded with
electrons emits the characteristic X-ray radiation and
bremsstrahlung. X-ray radiation spectra measured at
cooling with Cu and Cr targets are shown in Figs.2,3
respectively.
At heating, the crystal polarization is reversed and
surface, which directed to target, should be charged
positively. In this case, characteristic X-ray radiation
and bremsstrahlung goes from the crystal. This radiation
passes trough a thin foil and reaches the detector. At
crystal heating, the radiation spectra comprises the
characteristic K-lines of both crystal and target elements
(Figs.4,5). A part of radiation can go from the chamber
walls, as the body of the vacuum chamber is made with
brass. The registered radiation intensity corresponding
to cooling is higher than the one corresponding to
heating.
215
Fig.2. X-ray radiation spectrum measured with Cu
target thickness 20 μm at LiNbO3 crystal cooling. The
value of one channel is 0.036 keV. The distance between
the crystal and the copper foil is 7.5 mm. The total
number of counts in the spectrum is 8.391⋅106 for
16 minutes. The residual air pressure in the vacuum
chamber is measured to be 25 mTorr
0 5 10 15 20 25 30
104
105
Cu 8.05 keV
Cu 8.98 keV
8⋅104
6⋅104
4⋅104
2⋅104
Photon energy, keV
C
o
u
n
ts
p
e
r
c
h
a
n
n
e
l
0 5 10 15 20 25 30
0
1000
2000
3000
4000
X-Ray energy, keV
C
ou
nt
ra
te
Cu 8.05 keV
Nb 16.6 keV
Nb 18.95 keV
C
ou
nt
s
pe
r
ch
an
ne
l
Fig.4. X-ray radiation spectrum measured with Cu foil
and crystal elements during LiNbO3 crystal heating. The
distance between the crystal and the copper foil is
7.5 mm. The total number of counts in the spectrum is
4.975⋅105 for 8 minutes. The residual air pressure in the
vacuum chamber, which accommodates the crystal, is
measured to be 25 mTorr
Fig. 3. X-ray radiation spectrum measured with Cr
target thickness 18 μm at LiNbO3 crystal cooling for
one minute
Fig.5. X-ray radiation spectrum measured with Cr
target thickness 18 μm at LiNbO3 crystal heating for
one minute
3. THE MAXIMUM ENERGY OF X-RAYS
Experiments were made to measure the x-ray
spectra at dynamic conditions. During a thermal cycle,
the several spectra were measured for one minute each.
Eight spectra were measured at LiNbO3 heating
from - 50°C up to +125°C. Fig.6 shows a typical
dependence of measured maximum energy of X-rays in
spectra on the temperature. In this experiment, the
crystal of size 3.7x4.3x2.5 mm3 was used. It is seen
from the figure that as the crystal was heated the
maximum energy increased up to ~28 keV (20°C), and
then fell off to 17 keV (62°C) with a further rise up to
~30 keV (120°C). After heating was ceased, the
intensity and maximum energy of the x-rays went to
zero.
Similar measurements were also conducted on
cooling the crystal. A typical curve for the measured
maximum energy of radiation versus crystal temperature
at cooling conditions is shown in Fig.7. It increases, as
the crystal is cooled, and reaches its maximum of
~38 keV at room temperature (~20°C), then the x-ray
maximum energy drops to 0 keV (-40°C).
0 5 10 15 20
0
X-ray energy, keV
Co
un
tin
g
rat
Cr 5.41 keV
Cooling
C
ou
nt
s p
er
c
ha
nn
el
105
2⋅104
4⋅104
6⋅104
8⋅104
1000
2000
3000
4000
0 5 10 15 20 25
0
X-ray energy, keV
Nb 16.6 keV
Heating
C
ou
nt
in
g r
at
e
C
ou
nt
s
pe
r
ch
an
ne
l
Cr 5.41 keV
Nb 18.95 keV
g
CONCLUSIONS
The pyroelectric X-ray generator was created in
KIPT and its operation was demonstrated. Results of
our first experiments are mainly in agreement with the
results of earlier pioneer works [6, 8-11].
Continuous part of X-ray spectra in Figs.2-4 should be
due to bremsstrahlung of accelerated electrons in a
target and crystal. Thus, the maximum energy of X-rays
should be close to maximum energy of these electrons.
Therefore, Figs.6,7 show values close to maximum
energy of electrons in the generator.
ACKNOWLEDGMENTS
We are thankful to S.M. Shafroth and J.D.
Brownridge for encourage to start works in this field
and J.D. Brownridge for gift of pyrocrystals for our first
experiments, and to Crystal Technology Inc. what
supplied us with pyrocrystal samples. The work was
performed on STCU 1911 project.
216
Fig. 6. Maximum energy of X-rays versus crystal temperature at heating conditions
Fig.7. Maximum energy of X-rays versus crystal temperature at cooling conditions
REFERENCES
1. B. Rosenblum, P. Brunlich and J.P. Carrico. // Appl.
Phys. Lett. 25, 17(1974).
2. I.V. Strigushenko, S.G. Dmitriev and O.V.
Silant’eva // Sov. Phys. J Solid State 19, 1171
(1977).
3. V.S. Kortov, K.K. Shvarts, A.F. Zatsepin, A.I.
Gaprindashvili, A.V. Gulbis and Z.A. Grant // Sov.
Phys. J Solid State 21, 1092 (1979).
4. V.S. Kortov, A.F. Zatsepin, A.I.Gaprindashvili,
M.M. Pinaeva, V.S.Vasil"ev and I.A. Morozov //
Sov. Phys. Tech. Phys. 25(9) 1126 (1981).
5. J. Kalinovski and Z. Ddreger // Phys.Rev. B 36,
7840 (1987).
6. J.D. Brownridge, S.M. Shafroth, D. Trott, B. Stoner,
W. Hooke // Appl. Phys. Lett, 78, 1158 (2001).
7. G. Rosenman, D. Shur, Ya.E. Krasik, and A.
Dunaevsky // J. Appl. Phys. 88, 6109 (2000).
8. J.D. Brownridge, S.M. Shafroth: Electron preprint
http://arxiv.org/pdf/physics/0209079
9. J.D. Brownridge, Nature, 358, 287-288 (1992).
10. James Brownridge and Sol Raboy // J. Appl. Phys.
86, 640 (1999).
11. S.M. Shafroth, W. Kruger and J.D. Brownridge.
Time dependence of X-ray yield for two crystal X-
ray generators // Nucl. Instr. and Meth., A 422, 1-4
(1999).
СПЕКТРЫ ОТ ПИРОЭЛЕКТРИЧЕСКОГО РЕНТГЕНОВСКОГО ГЕНЕРАТОРА
В.И.Нагайченко, В.М.Санин, А.М.Егоров, А.В.Щагин
Описана конструкция рентгеновского генератора, основанного на пироэлектрическом кристалле LiNbO3.
Представлены некоторые свойства спектров излучения от рентгеновского генератора. Измерения спектров
были выполнены при нагревании и охлаждении кристалла с мишенями из меди и хрома. Представлена
максимальная энергия рентгеновского спектра в зависимости от температуры кристалла.
СПЕКТРИ ВІД ПІРОЕЛЕКТРИЧНОГО РЕНТГЕНІВСЬКОГО ГЕНЕРАТОРА
В.І.Нагайченко, В.М.Санін, О.М.Єгоров, А.В.Щагін
Описано конструкцію рентгенівського генератора, заснованого на піроелектричному кристалі
LiNbO3.Наведені деякі властивості спектрів випромінювання від рентгенівського генератора. Виміри
Temperature, degree Celsius
40
60 40 20 0 20 40 60 80 100 1200
20
Heating
M
ax
e
ne
rg
y,
M
ax
im
um
e
ne
rg
y,
k
eV
-40 20 0 20 40 60 80 100 120
0
20
40
Cooling
Temperature, degree Celcius
M
ax
im
um
e
ne
rg
y,
k
eV
http://arxiv.org/pdf/physics/0209079
217
спектрів були виконані при нагріванні й охолодженні кристалу з мішенями з міді і хрому. Представлено
максимальну енергію рентгенівського спектру в залежності від температури кристалу.
INTRODUCTION
1. THE X-RAY GENERATOR
3. THE MAXIMUM ENERGY OF X-RAYS
CONCLUSIONS
ACKNOWLEDGMENTS
Fig.7. Maximum energy of X-rays versus crystal temperature at cooling conditions
REFERENCES
СПЕКТРЫ ОТ ПИРОЭЛЕКТРИЧЕСКОГО РЕНТГЕНОВСКОГО ГЕНЕРАТОРА
СПЕКТРИ ВІД ПІРОЕЛЕКТРИЧНОГО РЕНТГЕНІВСЬКОГО ГЕНЕРАТОРА
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| id | nasplib_isofts_kiev_ua-123456789-79387 |
| institution | Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| issn | 1562-6016 |
| language | English |
| last_indexed | 2025-12-07T18:22:49Z |
| publishDate | 2004 |
| publisher | Національний науковий центр «Харківський фізико-технічний інститут» НАН України |
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| spelling | Nagaychenko, V.I. Sanin, V.M. Yegorov, A.M. Shchagin, A.V 2015-03-31T18:57:37Z 2015-03-31T18:57:37Z 2004 Spectra of pyroelectric X-ray generator / V.I. Nagaychenko, V.M. Sanin, A.M. Yegorov, A.V. Shchagin // Вопросы атомной науки и техники. — 2004. — № 2. — С. 214-216. — Бібліогр.: 11 назв. — англ. 1562-6016 PACS: 77.70.+a, 07.85.m https://nasplib.isofts.kiev.ua/handle/123456789/79387 The construction of X-ray generator based on a pyroelectric crystal LiNbO₃ is described. Some properties of radiation spectra from the X-ray generator are presented. Measurements of the spectra were performed at heating and cooling of the crystal with copper and chromium targets. The maximum energy in the X-ray spectrum versus
 crystal temperature is presented. Описано конструкцію рентгенівського генератора, заснованого на піроелектричному кристалі LiNbO₃.Наведені деякі властивості спектрів випромінювання від рентгенівського генератора. Виміри спектрів були виконані при нагріванні й охолодженні кристалу з мішенями з міді і хрому. Представлено максимальну енергію рентгенівського спектру в залежності від температури кристалу. Описана конструкция рентгеновского генератора, основанного на пироэлектрическом кристалле LiNbO₃. Представлены некоторые свойства спектров излучения от рентгеновского генератора. Измерения спектров были выполнены при нагревании и охлаждении кристалла с мишенями из меди и хрома. Представлена максимальная энергия рентгеновского спектра в зависимости от температуры кристалла. We are thankful to S.M. Shafroth and J.D.
 Brownridge for encourage to start works in this field
 and J.D. Brownridge for gift of pyrocrystals for our first
 experiments, and to Crystal Technology Inc. what
 supplied us with pyrocrystal samples. The work was
 performed on STCU 1911 project. en Національний науковий центр «Харківський фізико-технічний інститут» НАН України Вопросы атомной науки и техники Применение ускоренных пучков Spectra of pyroelectric X-ray generator Спектри від піроелектричного рентгенівського генератора Спектры от пироэлектрического рентгеновского генератора Article published earlier |
| spellingShingle | Spectra of pyroelectric X-ray generator Nagaychenko, V.I. Sanin, V.M. Yegorov, A.M. Shchagin, A.V Применение ускоренных пучков |
| title | Spectra of pyroelectric X-ray generator |
| title_alt | Спектри від піроелектричного рентгенівського генератора Спектры от пироэлектрического рентгеновского генератора |
| title_full | Spectra of pyroelectric X-ray generator |
| title_fullStr | Spectra of pyroelectric X-ray generator |
| title_full_unstemmed | Spectra of pyroelectric X-ray generator |
| title_short | Spectra of pyroelectric X-ray generator |
| title_sort | spectra of pyroelectric x-ray generator |
| topic | Применение ускоренных пучков |
| topic_facet | Применение ускоренных пучков |
| url | https://nasplib.isofts.kiev.ua/handle/123456789/79387 |
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