To the possibility of liquid dielectrics use in wakefield method of charged particle acceleration
Possibility of use of liquid dielectrics for dielectric loaded structures for wakefield acceleration of the charged particles is investigated. Application of liquid dielectric, at its circulation through structure, allows avoiding charge accumulation in volume of dielectric, heating of dielectric, l...
Gespeichert in:
| Datum: | 2013 |
|---|---|
| Hauptverfasser: | , , , |
| Format: | Artikel |
| Sprache: | English |
| Veröffentlicht: |
Національний науковий центр «Харківський фізико-технічний інститут» НАН України
2013
|
| Schriftenreihe: | Вопросы атомной науки и техники |
| Schlagworte: | |
| Online Zugang: | https://nasplib.isofts.kiev.ua/handle/123456789/111932 |
| Tags: |
Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
|
| Назва журналу: | Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| Zitieren: | To the possibility of liquid dielectrics use in wakefield method of charged particle acceleration / V.A. Kiselev, A.F. Linnik, I.N. Onishchenko, V.I. Pristupa // Вопросы атомной науки и техники. — 2013. — № 4. — С. 77-79. — Бібліогр.: 9 назв. — англ. |
Institution
Digital Library of Periodicals of National Academy of Sciences of Ukraine| id |
nasplib_isofts_kiev_ua-123456789-111932 |
|---|---|
| record_format |
dspace |
| spelling |
nasplib_isofts_kiev_ua-123456789-1119322025-02-09T23:28:20Z To the possibility of liquid dielectrics use in wakefield method of charged particle acceleration Про можливість застосування рідких діелектриків для кільватерного прискорення заряджених частинок О возможности применения жидких диэлектриков в кильватерном методе ускорения заряженных частиц Kiselev, V.A. Linnik, A.F. Onishchenko, I.N. Pristupa, V.I. Новые методы ускорения заряженных частиц Possibility of use of liquid dielectrics for dielectric loaded structures for wakefield acceleration of the charged particles is investigated. Application of liquid dielectric, at its circulation through structure, allows avoiding charge accumulation in volume of dielectric, heating of dielectric, loss of properties under the influence of ionizing radiation, characteristic for firm dielectrics. At change of temperature of liquid dielectric or mixing of liquid dielectrics with various value of dielectric permeability adjustment of dielectric permeability and working frequency of structure is easily feasible. Досліджується можливість використання рідких діелектриків у сповільнюваних структурах для кільватерного прискорення заряджених часток. Застосування рідкого діелектрика, при його циркуляції через структуру, дозволяє уникнути нагромадження заряду в об'ємі діелектрика, нагрівання діелектрика та втрати властивостей під впливом іонізуючого випромінювання, характерних для твердих діелектриків. При зміні температури рідкого діелектрика або змішуванні рідких діелектриків з різним значенням діелектричної проникності легко здійснити регулювання діелектричної проникності та робочої частоти структури. Исследуется возможность использования жидких диэлектриков в замедляющих структурах для кильватерного ускорения заряженных частиц. Применение жидкого диэлектрика, при его циркуляции через структуру, позволяет избежать накопления заряда в объеме диэлектрика, нагрева диэлектрика, потери свойств под воздействием ионизирующего излучения, характерных для твердых диэлектриков. При изменении температуры жидкого диэлектрика или смешивании жидких диэлектриков с различным значением диэлектрической проницаемости легко осуществима регулировка диэлектрической проницаемости и рабочей частоты структуры. 2013 Article To the possibility of liquid dielectrics use in wakefield method of charged particle acceleration / V.A. Kiselev, A.F. Linnik, I.N. Onishchenko, V.I. Pristupa // Вопросы атомной науки и техники. — 2013. — № 4. — С. 77-79. — Бібліогр.: 9 назв. — англ. 1562-6016 PACS: 29.17.+w, 41.75.Lx https://nasplib.isofts.kiev.ua/handle/123456789/111932 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 |
Новые методы ускорения заряженных частиц Новые методы ускорения заряженных частиц |
| spellingShingle |
Новые методы ускорения заряженных частиц Новые методы ускорения заряженных частиц Kiselev, V.A. Linnik, A.F. Onishchenko, I.N. Pristupa, V.I. To the possibility of liquid dielectrics use in wakefield method of charged particle acceleration Вопросы атомной науки и техники |
| description |
Possibility of use of liquid dielectrics for dielectric loaded structures for wakefield acceleration of the charged particles is investigated. Application of liquid dielectric, at its circulation through structure, allows avoiding charge accumulation in volume of dielectric, heating of dielectric, loss of properties under the influence of ionizing radiation, characteristic for firm dielectrics. At change of temperature of liquid dielectric or mixing of liquid dielectrics with various value of dielectric permeability adjustment of dielectric permeability and working frequency of structure is easily feasible. |
| format |
Article |
| author |
Kiselev, V.A. Linnik, A.F. Onishchenko, I.N. Pristupa, V.I. |
| author_facet |
Kiselev, V.A. Linnik, A.F. Onishchenko, I.N. Pristupa, V.I. |
| author_sort |
Kiselev, V.A. |
| title |
To the possibility of liquid dielectrics use in wakefield method of charged particle acceleration |
| title_short |
To the possibility of liquid dielectrics use in wakefield method of charged particle acceleration |
| title_full |
To the possibility of liquid dielectrics use in wakefield method of charged particle acceleration |
| title_fullStr |
To the possibility of liquid dielectrics use in wakefield method of charged particle acceleration |
| title_full_unstemmed |
To the possibility of liquid dielectrics use in wakefield method of charged particle acceleration |
| title_sort |
to the possibility of liquid dielectrics use in wakefield method of charged particle acceleration |
| publisher |
Національний науковий центр «Харківський фізико-технічний інститут» НАН України |
| publishDate |
2013 |
| topic_facet |
Новые методы ускорения заряженных частиц |
| url |
https://nasplib.isofts.kiev.ua/handle/123456789/111932 |
| citation_txt |
To the possibility of liquid dielectrics use in wakefield method of charged particle acceleration / V.A. Kiselev, A.F. Linnik, I.N. Onishchenko, V.I. Pristupa // Вопросы атомной науки и техники. — 2013. — № 4. — С. 77-79. — Бібліогр.: 9 назв. — англ. |
| series |
Вопросы атомной науки и техники |
| work_keys_str_mv |
AT kiselevva tothepossibilityofliquiddielectricsuseinwakefieldmethodofchargedparticleacceleration AT linnikaf tothepossibilityofliquiddielectricsuseinwakefieldmethodofchargedparticleacceleration AT onishchenkoin tothepossibilityofliquiddielectricsuseinwakefieldmethodofchargedparticleacceleration AT pristupavi tothepossibilityofliquiddielectricsuseinwakefieldmethodofchargedparticleacceleration AT kiselevva promožlivístʹzastosuvannârídkihdíelektrikívdlâkílʹvaternogopriskorennâzarâdženihčastinok AT linnikaf promožlivístʹzastosuvannârídkihdíelektrikívdlâkílʹvaternogopriskorennâzarâdženihčastinok AT onishchenkoin promožlivístʹzastosuvannârídkihdíelektrikívdlâkílʹvaternogopriskorennâzarâdženihčastinok AT pristupavi promožlivístʹzastosuvannârídkihdíelektrikívdlâkílʹvaternogopriskorennâzarâdženihčastinok AT kiselevva ovozmožnostiprimeneniâžidkihdiélektrikovvkilʹvaternommetodeuskoreniâzarâžennyhčastic AT linnikaf ovozmožnostiprimeneniâžidkihdiélektrikovvkilʹvaternommetodeuskoreniâzarâžennyhčastic AT onishchenkoin ovozmožnostiprimeneniâžidkihdiélektrikovvkilʹvaternommetodeuskoreniâzarâžennyhčastic AT pristupavi ovozmožnostiprimeneniâžidkihdiélektrikovvkilʹvaternommetodeuskoreniâzarâžennyhčastic |
| first_indexed |
2025-12-01T18:05:09Z |
| last_indexed |
2025-12-01T18:05:09Z |
| _version_ |
1850330120151105536 |
| fulltext |
ISSN 1562-6016. ВАНТ. 2013. №4(86) 77
TO THE POSSIBILITY OF LIQUID DIELECTRICS USE IN WAKEFIELD
METHOD OF CHARGED PARTICLE ACCELERATION
V.A. Kiselev, A.F. Linnik, I.N. Onishchenko, V.I. Pristupa
National Science Center “Kharkov Institute of Physics and Technology”, Kharkov, Ukraine
E-mail: onish@kipt.kharkov.ua
Possibility of use of liquid dielectrics for dielectric loaded structures for wakefield acceleration of the charged
particles is investigated. Application of liquid dielectric, at its circulation through structure, allows avoiding charge
accumulation in volume of dielectric, heating of dielectric, loss of properties under the influence of ionizing radia-
tion, characteristic for firm dielectrics. At change of temperature of liquid dielectric or mixing of liquid dielectrics
with various value of dielectric permeability adjustment of dielectric permeability and working frequency of struc-
ture is easily feasible.
PACS: 29.17.+w, 41.75.Lx;
INTRODUCTION
The idea of use of the dielectric loaded structures for
transformation of energy of an electronic bunch to elec-
tromagnetic radiation was put forward in 1947 [1].
To advantages of dielectric structures necessary to
refer the maximum simplicity of their production and
high electric durability that is especially important at
development of short-wave area of lengths of waves.
The dielectric wave guide has no strips of blackness and
at small values of dielectric permeability can provide
quite weak dispersion of electromagnetic waves in the
wide frequency range in the field of relativistic phase
speeds [2].
Now is the object of intensive experimental and
theoretical study a new method of wakefield accelera-
tion of the charged particles, using wakefields generated
by the short high charge electron bunches passing
through dielectric loaded accelerating structure [3, 4].
Commonly a dielectric loaded accelerating structure
(DLA) is the single-layered dielectric tube with an inner
vacuum channel for the passing electron beams. A di-
electric cylinder is inserted into a conductive copper
jacket.
Wakefield acceleration assumes the energy transfer
from a high-current low-energy electron beam (driver)
to a low-current high-energy accelerating beam of
charged particles (witness). While passing the wave-
guide the driver beam generates Cherenkov electromag-
netic waves (wakefields) with the longitudinal fields up
to 100 MV magnitudes to be used for the witness beam
acceleration.
As dielectric new types of ceramics on the basis of
MgхCa1-хTiО3 (MCT ceramics), oxides of aluminum
(alumina 96S), and also structure from cordierite,
quartz, diamond, and others were used, but the short-
comings applied dielectrics were the reason of it, main
from which are: charge accumulation, loss of properties
under the influence of ionizing radiation and a dielectric
overheat [5].
We propose to apply in DLA liquid dielectric that
gives the chance, thanks to a channel and updating of
liquid dielectric considerably to eliminate charge accu-
mulation, loss of properties under the influence of ioniz-
ing radiation and its overheat.
1. DESIGN OF THE DLA WITH LIQUID
DIELECTRIC
In Fig. 1 the scheme of flowing DLA with liquid di-
electric is submitted. In a metal waveguide (1) the glass
tube with lateral walls (2) is pasted. Between a glass
tube and a waveguide there is a liquid dielectric which
can be pumped over via the heat exchanger (3) by
means of the pump (4)
Fig. 1. Scheme of flowing dielectric structure:
1 – liquid dielectric; 2 – glass tube; 3 – heat exchanger;
4 – water pump; 5 – copper waveguide;
6 – electrons bunches
As liquid dielectric we applied the condenser oil
having a smaller of dielectric losses factor (tan δ) in
comparison with transformer oil. Condenser oil filled
space between a copper waveguide and a glass tube.
Internal diameter of a waveguide – 8.6 cm. Diameter
of the channel on an axis of structure of 2.2 cm, struc-
ture length – 23 cm. Thickness of a glass tube – 2 mm.
Thanks to small glass thickness and contact with liquid
dielectric, in glass there is no considerable accumulation
of a charge and its temperature is equal to temperature
of liquid dielectric.
Now various grades of glass with an electric durabil-
ity up to 700 kV/cm, with dielectric permeability ε from
3 to 12 and high radiation stability [6] Therefore the
glass tube practically doesn't worsen structure parame-
ters are issued.
2. A TUNABLE DLA STRUCTURE
WITH CONDENSER OIL
The need for frequency tuning of any accelerating
structure arises from the fact that the frequency of the
assembled accelerating structure will, in general, differ
from the design due to various sources of error.
Volume of the dielectric material inside the metal
waveguide and its dielectric constant determine the dis-
persion relation of the accelerating mode. Frequency
ISSN 1562-6016. ВАНТ. 2013. №4(86) 78
errors in a DLA structure are dominantly caused by ma-
chining tolerance of the dielectric dimensions and di-
electric constant heterogeneity.
Earlier in [7] it was offered to carry out fine tuning
of dielectric permeability of firm dielectrics, a way
change of temperature of dielectric, but uniform on vol-
ume change of temperature of firm dielectric a complex
challenge, besides such changes are quite inertial. Much
more simply, in our opinion to change and maintain
stable temperature of liquid dielectric when using the
scheme shown in Fig. 1.
Dielectric permeability of condenser oil was deter-
mined at full filling with oil of section of a rectangular
waveguide by two values of lengths of waves in a
waveguide: without dielectric and with dielectric [8]. At
value of magnetic permeability μ = 1 length of a wave
in the wave guide which has been completely filled with
dielectric - λd is defined from:
. (1)
Where λ0 − wave length in free space, λc – the criti-
cal length of a wave.
From here dielectric permeability is equal:
. (2)
The measuring line with a waveguide 23⋅10 mm2,
raised on a wave of the H10 type with a critical length of
a wave λc = 4.6 cm was used. Wave length without oil
was equal in the short-circuited measuring line
λw = 6.4 cm, (that corresponds to wave length in free
space λ0 = 3.74 cm), and when filling line with con-
denser oil it decreased to λd=3.065 cm (at a temperature
of 20°C). Counted from (2) value of dielectric perme-
ability makes ε = 2.15.
For research of dependence of dielectric permeabil-
ity of condenser oil from temperature values of its di-
electric permeability were measured in range of tem-
peratures of 10…60°C.
Results of measurements are presented in Fig. 2.
Fig. 2. Dependence of dielectric permeability
and tangent of angle of losses of condenser oil from
temperature
In the same drawing dependence of dielectric losses
factor of condenser oil on temperature is presented. The
dielectric losses factor was defined from a ratio [8]:
tgδ=2Emin/πEmax. (3)
Emin, Emax value of intensity of fields in the minimum
and maximum amplitude standing wave in measuring
line.
Linear change of dielectric permeability of con-
denser oil from temperature does possible to carry out
simple and fast frequency trim of DLA. For our DLA
Δf/ΔT ≈ 2 MHz/°C.
Application of liquid dielectrics also allows carrying
out smooth change of dielectric permeability in wide
range when mixing liquid dielectrics with various value
ε. In Fig. 3 dependence of dielectric permeability of a
mix of condenser and castor oils is presented at the var-
ious contents castor oil in mix.
Fig. 3. Dependence of dielectric permeability
of a mix of condenser and castor oil on the content
of castor oil in a mix
In case of application of a mix of liquid dielectrics
the scheme of a supply of dielectric structure becomes
complicated, but there is an opportunity considerable
(several times) changes of dielectric constant and work-
ing frequency of DLA
3. EXPERIMENT
Experimental researches on excitation of wakefields
by sequence of clots of relativistic electrons in slowing-
down structure with liquid dielectric were carried out.
Along a structure axis with liquid dielectric the se-
quence from 6000 bunches of relativistic electrons, cre-
ated by means of the linear resonant accelerator was
injected. Energy of electrons – 4.5 MeV, a charge of
each bunch – 0.16 nC, the frequency of following of
bunches – 2805 MHz.
Fig. 4. Oscillograms of Ez of a component of a raised
wakefields (above) a) DLA with the fluoroplastic;
b) with DLA with liquid dielectric. On the bottom
oscillograms the current of electrons getting on walls
of a waveguide is shown
In Fig. 4 (the top oscillograms) Ez values of a com-
ponent of the raised wakefields registered by the mi-
crowave oven by a probe which settled down at an out-
put end of a waveguide at dielectric application from
fluoroplastic (see Fig. 4,a) and with condenser oil (see
Fig. 4,b) are presented.
On the bottom oscillograms the current of electrons
getting on walls of a waveguide is shown.
ISSN 1562-6016. ВАНТ. 2013. №4(86) 79
In DLA with liquid dielectric amplitude of a longi-
tudinal component of a wakefields is close to field am-
plitude in DLA from fluoroplastic.
The increase in current at a waveguide in a case with
liquid dielectric is caused by increase of size of a cross
component of a wakefield, but if in case of structure
with fluoroplastic these electrons collect in volume of
dielectric, at application of liquid dielectric the charge
flows down on a copper waveguide of Fig. 4 (the bot-
tom oscillogram).
CONCLUSIONS
Application of liquid dielectric in DLA thanks to its
channel and hashing allows to avoid charge accumula-
tion in volume of dielectric, heating of dielectric, loss of
properties under the influence of ionizing radiation,
characteristic for firm dielectrics. There is a possibility
of expeditious control of working frequency of DLA at
change of temperature of liquid dielectric or mixing of
liquid dielectrics with various value of dielectric perme-
ability.
Big prospect for application in DLA structures have,
fluororganic liquids, for example fluororganic liquids
C8F16 with dielectric permeability ε = 2, tg δ <10-4,
ρ > (1012…1015) Оhm·m and with the electric durability
of 500 kV/cm. Fluororganic liquids it isn't combustible,
aren't toxic and don't mix up with water [9].
Application of liquid dielectrics will allow to expand
considerably DLA use for wakefield acceleration and
allows avoiding charge accumulation in volume of di-
electric, heating of dielectric, loss of properties under
the influence of ionizing radiation.
REFERENCES
1. V.L. Ginzburg. About use of effect of Cherenkov for
the radiation of radio waves // Dokl. Academy of
Sciences of the USSR. 1947, v. 56, № 3.
2. A.I Akhiyezer, Ya.B Faynberg. Slow electromag-
netic waves // UFN. 1951, v. 44, № 3.
3. W. Gai, P. Schoessow, T. Cole, et al. Experimental
Demonstration of Wake-Field Effects in Dielectric
Structures // Phys. Rev. Lett. 1988, v. 61, p. 2756-
2758.
4. I. Onishchenko, A. Berezin, V. Kiselev, et al. Di-
electric Wake-field Generator // 12th Intern. Conf.
BEAMS’ 98, Haifa, Israel, Inc. IEEE Catalog 1998,
v. 2, p. 756-759.
5. O.A. Valdner, A.V. Shalnov, A.N. Didenko. Accel-
erating waveguides. M.: "Atomizdat". 1973, p. 197.
6. V.I. Arbuzov. Bases radiation optical materials.
ITMO. SPb. 2008, p. 141.
7. C. Jing, A. Kanareykin, J.G. Power, et al. Experi-
mental Demonstration of Wakefield Acceleration in
a Tunable Dielectric Loaded Accelerating Structure.
// Phys. Rev. Lett. 2011, v. 106, p. 164802.
8. V.D. Shestopalov, K.P. Yatsuk. Methods of meas-
urements of dielectric constant of substance at ultra-
high frequencies // UFN. 1961, v. 74, p. 721-755.
9. S.M. Korobeynikov. Dielectric materials. Novosi-
birsk State. University, 2000, p. 64.
Article received 25.04.2013.
О ВОЗМОЖНОСТИ ПРИМЕНЕНИЯ ЖИДКИХ ДИЭЛЕКТРИКОВ В КИЛЬВАТЕРНОМ МЕТОДЕ
УСКОРЕНИЯ ЗАРЯЖЕННЫХ ЧАСТИЦ
В.А. Киселёв, А.Ф. Линник, И.Н. Онищенко, В.И. Приступа
Исследуется возможность использования жидких диэлектриков в замедляющих структурах для кильва-
терного ускорения заряженных частиц. Применение жидкого диэлектрика, при его циркуляции через струк-
туру, позволяет избежать накопления заряда в объеме диэлектрика, нагрева диэлектрика, потери свойств под
воздействием ионизирующего излучения, характерных для твердых диэлектриков. При изменении темпера-
туры жидкого диэлектрика или смешивании жидких диэлектриков с различным значением диэлектрической
проницаемости легко осуществима регулировка диэлектрической проницаемости и рабочей частоты струк-
туры.
ПРО МОЖЛИВІСТЬ ЗАСТОСУВАННЯ РІДКИХ ДІЕЛЕКТРИКІВ ДЛЯ КІЛЬВАТЕРНОГО
ПРИСКОРЕННЯ ЗАРЯДЖЕНИХ ЧАСТИНОК
В.О. Кисельов, А.Ф. Лінник, І.М. Оніщенко, В.І. Приступа
Досліджується можливість використання рідких діелектриків у сповільнюваних структурах для кільвате-
рного прискорення заряджених часток. Застосування рідкого діелектрика, при його циркуляції через струк-
туру, дозволяє уникнути нагромадження заряду в об'ємі діелектрика, нагрівання діелектрика та втрати влас-
тивостей під впливом іонізуючого випромінювання, характерних для твердих діелектриків. При зміні тем-
ператури рідкого діелектрика або змішуванні рідких діелектриків з різним значенням діелектричної проник-
ності легко здійснити регулювання діелектричної проникності та робочої частоти структури.
|