Сomparative analysis of acceleration of test electron bunch by train of bunches in the dielectrical waveguide and resonator filled with plasma
Results of numerical simulation of acceleration of test bunch by sequence of relativistic electron bunches in the dielectrical cylindric slowing-down structure filled with plasma for the cases opened and closed by the conductive grid of output end face of structure are provided. The entrance end f...
Gespeichert in:
| Datum: | 2018 |
|---|---|
| Hauptverfasser: | , , |
| Format: | Artikel |
| Sprache: | English |
| Veröffentlicht: |
Національний науковий центр «Харківський фізико-технічний інститут» НАН України
2018
|
| Schriftenreihe: | Вопросы атомной науки и техники |
| Schlagworte: | |
| Online Zugang: | http://dspace.nbuv.gov.ua/handle/123456789/147289 |
| 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: | Сomparative analysis of acceleration of test electron bunch by train of bunches in the dielectrical waveguide and resonator filled with plasma / P.I. Markov, I.N. Onishchenko, G.V. Sotnikov // Вопросы атомной науки и техники. — 2018. — № 3. — С. 53-57. — Бібліогр.: 8 назв. — англ. |
Institution
Digital Library of Periodicals of National Academy of Sciences of Ukraine| id |
irk-123456789-147289 |
|---|---|
| record_format |
dspace |
| spelling |
irk-123456789-1472892019-02-15T01:23:59Z Сomparative analysis of acceleration of test electron bunch by train of bunches in the dielectrical waveguide and resonator filled with plasma Markov, P.I. Onishchenko, I.N. Sotnikov, G.V. Новые и нестандартные ускорительные технологии Results of numerical simulation of acceleration of test bunch by sequence of relativistic electron bunches in the dielectrical cylindric slowing-down structure filled with plasma for the cases opened and closed by the conductive grid of output end face of structure are provided. The entrance end face has been closed by the conductive grid. The initial sizes and energy of all bunches were identical. The distance between bunches of sequence is equal to the wavelength of electromagnetic field in the structure. The test bunch followed the last bunch of the sequence. Acceleration of test bunch at changing of number of drive bunches in a sequence was investigated. We have found out that at certain number of bunches in the resonator it is possible to obtain significantly greater acceleration, than in waveguide. Представлені результати чисельного моделювання прискорення тестового згустка послідовністю релятивістських електронних згустків у плазмово-діелектричній циліндричній сповільнюючiй структурі для випадків відкритого й закритого провідною сіткою вихідного торця структури. Вхідний торець був закритий провідною сіткою. Початкові розміри й енергія всіх згустків були однаковими. Відстань між згустками послідовності дорівнювала довжині хвилі електромагнітного поля в структурі. Тестовий згусток йшов за останнім згустком послідовності. Досліджувалося прискорення тестового згустку при зміні кількості згустків послідовності. Ми виявили, що для хвилеводу спостерігаються дві стадії: 1) лінійне зростання енергії прискореного тестового згустка зі збільшенням кількості згустків драйверної послідовності, за яким іде 2) практично незмінне значення енергії згустка при зміні кількості драйверних згустків. Для резонатора відзначені дві стадії лінійного зростання енергії й незмінного значення енергії тестового згустка зі збільшенням кількості згустків драйверної послідовності повторюються попарно кілька разів. При певній кількості згустків у резонаторі можна одержати суттєво більше прискорення, ніж у хвилеводі. Представлены результаты численного моделирования ускорения тестового сгустка последовательностью релятивистских электронных сгустков в плазменно-диэлектрической цилиндрической замедляющей структуре для случаев открытого и закрытого проводящей сеткой выходного торца структуры. Входной торец был закрыт проводящей сеткой. Начальные размеры и энергия всех сгустков были одинаковыми. Расстояние между сгустками последовательности равнялось длине волны электромагнитного поля в структуре. Тестовый сгусток следовал за последним сгустком последовательности. Исследовалось ускорение тестового сгустка при изменении количества сгустков последовательности. Мы обнаружили, что для волновода наблюдаются две стадии: 1) линейный рост энергии ускоренного тестового сгустка с увеличением количества сгустков драйверной последовательности, за которым следует 2) практически, неизменное значение энергии сгустка при изменении количества драйверных сгустков. Для резонатора отмеченные две стадии линейного роста энергии и постоянного значения энергии тестового сгустка с увеличением количества сгустков драйверной последовательности повторяются попарно несколько раз. При определённом количестве сгустков в резонаторе можно получить существенно большее ускорение, чем в волноводе. 2018 Article Сomparative analysis of acceleration of test electron bunch by train of bunches in the dielectrical waveguide and resonator filled with plasma / P.I. Markov, I.N. Onishchenko, G.V. Sotnikov // Вопросы атомной науки и техники. — 2018. — № 3. — С. 53-57. — Бібліогр.: 8 назв. — англ. 1562-6016 PACS: 41.75.Ht, 41.75.Lx, 41.75.Jv, 96.50.Pw, 533.9 http://dspace.nbuv.gov.ua/handle/123456789/147289 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 |
| collection |
DSpace DC |
| language |
English |
| topic |
Новые и нестандартные ускорительные технологии Новые и нестандартные ускорительные технологии |
| spellingShingle |
Новые и нестандартные ускорительные технологии Новые и нестандартные ускорительные технологии Markov, P.I. Onishchenko, I.N. Sotnikov, G.V. Сomparative analysis of acceleration of test electron bunch by train of bunches in the dielectrical waveguide and resonator filled with plasma Вопросы атомной науки и техники |
| description |
Results of numerical simulation of acceleration of test bunch by sequence of relativistic electron bunches in the
dielectrical cylindric slowing-down structure filled with plasma for the cases opened and closed by the conductive
grid of output end face of structure are provided. The entrance end face has been closed by the conductive grid. The
initial sizes and energy of all bunches were identical. The distance between bunches of sequence is equal to the
wavelength of electromagnetic field in the structure. The test bunch followed the last bunch of the sequence. Acceleration of test bunch at changing of number of drive bunches in a sequence was investigated. We have found out
that at certain number of bunches in the resonator it is possible to obtain significantly greater acceleration, than in
waveguide. |
| format |
Article |
| author |
Markov, P.I. Onishchenko, I.N. Sotnikov, G.V. |
| author_facet |
Markov, P.I. Onishchenko, I.N. Sotnikov, G.V. |
| author_sort |
Markov, P.I. |
| title |
Сomparative analysis of acceleration of test electron bunch by train of bunches in the dielectrical waveguide and resonator filled with plasma |
| title_short |
Сomparative analysis of acceleration of test electron bunch by train of bunches in the dielectrical waveguide and resonator filled with plasma |
| title_full |
Сomparative analysis of acceleration of test electron bunch by train of bunches in the dielectrical waveguide and resonator filled with plasma |
| title_fullStr |
Сomparative analysis of acceleration of test electron bunch by train of bunches in the dielectrical waveguide and resonator filled with plasma |
| title_full_unstemmed |
Сomparative analysis of acceleration of test electron bunch by train of bunches in the dielectrical waveguide and resonator filled with plasma |
| title_sort |
сomparative analysis of acceleration of test electron bunch by train of bunches in the dielectrical waveguide and resonator filled with plasma |
| publisher |
Національний науковий центр «Харківський фізико-технічний інститут» НАН України |
| publishDate |
2018 |
| topic_facet |
Новые и нестандартные ускорительные технологии |
| url |
http://dspace.nbuv.gov.ua/handle/123456789/147289 |
| citation_txt |
Сomparative analysis of acceleration of test electron bunch by train of bunches in the dielectrical waveguide and resonator filled with plasma / P.I. Markov, I.N. Onishchenko, G.V. Sotnikov // Вопросы атомной науки и техники. — 2018. — № 3. — С. 53-57. — Бібліогр.: 8 назв. — англ. |
| series |
Вопросы атомной науки и техники |
| work_keys_str_mv |
AT markovpi somparativeanalysisofaccelerationoftestelectronbunchbytrainofbunchesinthedielectricalwaveguideandresonatorfilledwithplasma AT onishchenkoin somparativeanalysisofaccelerationoftestelectronbunchbytrainofbunchesinthedielectricalwaveguideandresonatorfilledwithplasma AT sotnikovgv somparativeanalysisofaccelerationoftestelectronbunchbytrainofbunchesinthedielectricalwaveguideandresonatorfilledwithplasma |
| first_indexed |
2025-07-11T01:46:53Z |
| last_indexed |
2025-07-11T01:46:53Z |
| _version_ |
1837313220366303232 |
| fulltext |
ISSN 1562-6016. ВАНТ. 2018. №3(115) 53
COMPARATIVE ANALYSIS OF ACCELERATION OF TEST ELECTRON
BUNCH BY TRAIN OF BUNCHES IN THE DIELECTRICAL
WAVEGUIDE AND RESONATOR FILLED WITH PLASMA
P.I. Markov, I.N. Onishchenko, G.V. Sotnikov
National Science Center “Kharkov Institute of Physics and Technology”, Kharkov, Ukraine
E-mail: pmarkov@kipt.kharkov.ua
Results of numerical simulation of acceleration of test bunch by sequence of relativistic electron bunches in the
dielectrical cylindric slowing-down structure filled with plasma for the cases opened and closed by the conductive
grid of output end face of structure are provided. The entrance end face has been closed by the conductive grid. The
initial sizes and energy of all bunches were identical. The distance between bunches of sequence is equal to the
wavelength of electromagnetic field in the structure. The test bunch followed the last bunch of the sequence. Accel-
eration of test bunch at changing of number of drive bunches in a sequence was investigated. We have found out
that at certain number of bunches in the resonator it is possible to obtain significantly greater acceleration, than in
waveguide.
PACS: 41.75.Ht, 41.75.Lx, 41.75.Jv, 96.50.Pw, 533.9.
INTRODUCTION
For obtaining high rates of acceleration of charged
particles by wakefield it is necessary to use single drive
bunch with great charge [1].
Another way of increasing of amplitude of the ac-
celerating wakefield is using of periodic sequence of
drive bunches with smaller charge [2 - 4].
Earlier for stabilization of the transverse motion of
the drive and accelerated bunches and, thus, for obtain-
ing the accelerated bunches of particles with small emit-
tance it was proposed to fill the drift channel of dielec-
tric structure with plasma [5]. Such structure was called
the plasma-dielectric wakefield accelerator (PDWA). At
that for creation of the accelerating wakefield only a
single drive bunch was used [5 - 7].
Research of test electron bunch acceleration in
PDWA where the wakefield is created by sequence of
drive bunches is of interest. We will carry out compara-
tive analysis of acceleration in two kinds of accelerating
structures: opened from the output end face the wave-
guide and closed the resonator.
STATEMENT OF THE PROBLEM
The dielectric tube with an inner radius a and dielec-
tric constant is inserted into a cylindrical metal wave
guide of radius b . Length of a metal waveguide L co-
incides with length of a dielectric tube. The entrance
end face of a waveguide is closed by the metal grid
transparent for electron bunches. In case of the resona-
tor the output end face of structure is closed by the met-
al grid also. The internal area of a dielectric tube is
filled by uniform plasma of density pn . Into the slow-
ing-down structure the sequence of electron bunches is
injected. After the certain delay time delt the test elec-
tron bunch is injected in the system. The studied system
is schematically shown in Fig. 1.
We investigated change of energy of test bunch elec-
trons at the system output end face at the motion in the
electromagnetic fields created by drive sequence de-
pending on number of bunches in the sequence. In Table
the parameters used in calculation are given.
Fig. 1. General view of the dielectric structure, excited
by sequence of electron bunches. Into a metal cylindri-
cal waveguide of length L the dielectric plug is inserted
(yellow color). The internal area of dielectric tube is
filled by plasma. Drive electron bunches (pink color)
propagate along a cylinder axis from left to right.
Blue cylinder shows test electron bunch
Parameters used in calculation
Inner radius of dielectric tube a 0.5 mm
Outer radius of dielectric tube b 0.6 mm
Operating frequency f 357.2 GHz
Waveguide length L 4.196 mm (5λ)
Relative dielectric constant ε 3.75 (quartz)
Bunch energy E0 5 GeV
Total drive bunch charge 3 nC
Total witness bunch charge 0.3 nC
Bunch diameter 2rb 0.9 mm
Bunch axial RMS dimension 2σ
(Gaussian charge distribution)
0.1 mm
Full bunch length used in PIC simulation 0.2 mm
Number of bunches in drive sequence 1…50
Test bunch length (homogeneous
charge distribution)
0.4 mm
Delay injection time of test bunch
releative to the last drive bunch tdel
1.151 ps
Plasma density np0 4.4110
14
cm
-3
Ratio mi /me of model plasma 1836 (hydrogen)
ISSN 1562-6016. ВАНТ. 2018. №3(115) 54
INJECTION OF BUNCHES
AND TREATMENT OF NUMERICAL
SIMULATION RESULTS
The analysis of acceleration of test electron bunch by
sequence of drive bunches was carried out by us by means
of 2.5-dimensional numerical code in the following way:
1. The given number of drive bunches was injected into
the investigated structure.
2. Later the delay time
delt after the beginning of the
last drive bunch injection the test bunch was injected and
moved after drive bunches in the electromagnetic field
created by them up to the system output end.
3. From the calculated values of electrons energies of
the test bunch, which was near output end face of structure,
the maximum energy was calculated. This energy was
taken as test bunch acceleration.
4. Having done the actions described above in items
1…3 for different number of drive bunches, the depend-
ence of test bunch electrons energy on number of drive
bunches obtained. At that two cases of longitudinal bound-
ary conditions were investigated: the resonator (tangential
components of electric field are equal to zero) and wave-
guide (impedance matching of dielectric waveguide and
free space).
RESULTS OF 2.5D-PIC CODE SIMULATION
As examples of numerical simulation results of accel-
eration process in PDWA are shown in Fig. 2: the longi-
tudinal zF z and transverse rF z forces affecting on
test electron and the phase plane energy – the longitudi-
nal coordinate of the last drive and test bunches when
injecting one, two, three and four drive bunches in the
resonator and the waveguide. Figures correspond to
time when the last drive bunch of a sequence approach-
es output end face of the slowing-down structure. As
appears from Fig. 2, the increase in number of drive
bunches leads to growth of longitudinal force zF z
and, as a result, to growth of the maximum energy of
the accelerated electrons of test bunch.
Fig. 2. Longitudinal Fz(z) and transverse Fr(z) forces affecting on test electron (r = 0.2 mm),
phase plane energy – the longitudinal coordinate of the last drive (magenta dots) and test (cyan dots) bunches when
injecting one (a, e), two (b, f), three (c, g) and four (d, h) drive bunches for resonator (a, b, c, d) and waveguide (e, f, g, h)
In Fig. 3 the dependence of electron energy gain of
test bunch on number of the injected drive bunches for
the resonator and waveguide is shown.
Fig. 3. Dependence of electron energy gain of test bunch
on number of the injected drive bunches for the resonator
(red curve) and waveguide (blue curve)
Symbols in Fig. 3 have shown the exact values of
energy gain of test bunch electrons obtained at numeri-
cal experiment, and curves represent average depend-
ence.
To understand behaviour of the dependences given
on Fig. 3, we analyzed structure of the longitudinal
forces zF z affecting on electrons, depending on
number of the injected drive bunches for the resonator
and waveguide.
Colour maps for longitudinal force zF z at
0.2 mmr depending on number of the injected
bunches in case of resonator accelerating structure
(Fig. 4,a) and in case of the waveguide accelerating
structure (Fig. 4,b) are given in Fig. 4. Time for which
configuration of forces are given in Fig. 4, correspond
to the moment of approach of the last drive bunches of
sequence to output end face of structure.
a
b c d
e f g h
ISSN 1562-6016. ВАНТ. 2018. №3(115) 55
Fig. 4. Configuration of the longitudinal forces zF z
acting on test electron, depending on number of the in-
jected drive bunches for the resonator (a) and waveguide
(b) at 2r 0. mm in the form of colour map
As one can see in Fig. 4,a, when changing a number
of drive bunches from 1 to 20 wakefield wave, reflected
from output end face of the resonator (backward wave),
moves to its input end face, but does not reach it. At
injection of the 21st drive bunch the backward wave
reaches input end face of the resonator. From here when
increasing a number of drive bunches injected in the
system the wave reflected from input end face of the
resonator (direct wave) forms. This wave influences
electrons of test bunch together with wakefield wave
and accelerates them. Let's note that at injection of 23
drive bunches the small decay of strength of the longi-
tudinal accelerating field resulting in local minimum on
dependence of energy increase of test bunch electrons
on number of the injected drive bunches is observed
(see Fig. 3). When injecting 24…26 drive bunches there
is rapid growth of strength of the longitudinal accelerat-
ing field that leads to sharp increase in energy of test
electrons. When further increasing number of drive
bunches the strength of longitudinal electric field in area
where the test bunch is located, falls down a little that
leads to weaker acceleration of bunch, than in maxi-
mum. When injecting 41…42 drive bunches in the reso-
nator are observed the decay of the longitudinal acceler-
ating field strength leading to local minimum on curve
in Fig. 3 again. Injection of the next 44th bunch leads to
sharp increase in energy of the accelerated bunch at the
resonator output end face.
The configuration of longitudinal forces zF z for
waveguide shown in Fig. 4,b has more regular character,
than for the resonator, described above (see Fig. 4,a). It
is caused by absence of reflection of electromagnetic
fields from output end face of waveguide. Therefore at
the time when the last drive bunch approaches to output
end face of structure the identical amount of the periods
of electromagnetic wakefield forms in the drift space
independently of number of drive bunches of sequence.
Only field amplitude changes. In the analyzed structure
at the same time there can be no more than five bunches
which fields summed up: either 5 drive, or 1 test and
4 drive. Therefore in Fig. 4,b the maximum of force
zF
is reached for 4 drive bunches. When increasing in a
number of drive bunches little changes of amplitude
zF
in comparison with the maximum value are observed.
It is possible to mark out some stages of acceleration
of test bunch connected with number of bunches of
drive sequence in Fig. 3.
At the first stage while the group front of wakefield
wave from the first drive bunch does not go beyond
output end face of system, the linear growth of energy
of the accelerated test bunch with increase in number of
bunches of drive sequence is observed. In our research
this stage is observed at injection from 1 to 4 drive
bunches. Distinctions in behavior of the resonator and
waveguide at the first stage it is not observed (see
Fig. 3).
At the second stage the additional growth of energy
of the accelerated test bunch when increasing in a num-
ber of bunches of drive sequence is not observed. For
waveguide it is connected with that the electromagnetic
field leaves system through output end face and does
not give contribution to acceleration of electrons of test
bunch. It is limit stage of test bunch acceleration for
waveguide case. For resonator case reflection of elec-
tromagnetic wave from output end face is observed.
This reflected wave moves towards to test bunch and
therefore does not provide cophased energy increase of
its electrons. At the end of the second stage the reflected
wave reaches the input end face of the resonator. In our
research the second stage of acceleration is observed at
injection from 5 to 22 drive bunches. Let's note almost
identical the curve of acceleration at the second stage
for the resonator with waveguide curve.
The next stages of acceleration of test bunch are ob-
served only for the resonator.
The third stage is similar to the first one as for an
energy growth of test electrons and it is connected with
additional acceleration of electrons in the field of the
wave reflected both from output and from input resona-
tor end faces. This stage finishes when the wave reaches
output end faces of the resonator for the second time. In
our case the third stage of acceleration is observed at
injection from 23 to 26 drive bunches.
Then the fourth stage similar to the second one as
for relative constancy of test electron energy is ob-
served. This is connected with the motion of the wave
three times reflected from resonator end faces towards
to test bunch that does not increase its energy (from 27
to 41 drive bunches).
The fourth stage is changed to fifth one when an en-
ergy growth of test electrons is observed again (from 42
to 44 drive bunches).
And, finally, at the sixth stage the falling-down area
of energy change of test electrons is observed (from 45
to 50 drive bunches). We believe that it is connected
with breakdown of cophased addition of fields of the
backward and direct waves in the resonator.
Let's note that in work [8] authors already observed
alternation of stages of linear growth and constant value
ISSN 1562-6016. ВАНТ. 2018. №3(115) 56
of longitudinal electric field strength as functions of
time at injection of sequence of bunches in the rectangu-
lar dielectric resonator.
Fig. 5. Dependence of density of plasma electrons npe
after injection of single drive bunch for the resonator in
the form of colour map
To find out the reason of impairment of cophased
addition of fields of the backward and direct waves in
the resonator when a number of drive bunches is more
than 39 we analyze behavior of plasma in the drift
channel. In Fig. 5 dependence of density of plasma elec-
trons
pen after injection of single drive bunch for the
resonator in the form of color map is shown. In the pic-
ture it is possible to see that after injection of one drive
bunch it appears a density
pen modulated with the peri-
od of transverse force rF z change (i.e. with plasma
wavelength).
When increasing number of the injected drive
bunches a change of plasma density become more es-
sential. In Fig. 6 dependence
pen and
pin after injection
of different number of drive bunches for the resonator
(see Fig. 6, a,b) and waveguide (see Fig. 6,c,d) is
shown, 0.2 mmr . The horizontal dashed line shows
the initial plasma density
0pn in system. As follows
from Fig. 6,a and c, after injection of 30 drive bunches
in the resonator the electron density
pen falls more, than
twice, and after injection of 50 bunches plasma elec-
trons in the resonator are nearly absent. Plasma ion den-
sity as function of drive bunches number decreases sig-
nificantly more weakly than plasma electron density
(see Fig. 6,b,d), however, already at injection of 50
bunches in the resonator 00.5pi pn n .
Carrying out of plasma from system when injecting
a large number of drive bunches leads to change of its
frequency characteristics. In result the resonant excita-
tion of the electromagnetic waves excited by drive
bunches which are periodically injected in the resonator
is violated.
Fig. 6. Dependence of plasma density of electrons npe and ions npi after injection of different number of drive bunches
for the resonator (a, b) and waveguide (c, d), r 0.2 mm
CONCLUSIONS
At numerical simulation of acceleration of test
bunch by the field of sequence of drive bunches in case
of plasma filling of the drift channel we have found
some stages of acceleration of test bunch connected
with a number of drive sequence bunches.
For waveguide two stages are observed: 1) linear
growth of energy of the accelerated electrons of test
bunch with increase in number of drive bunches of a
sequence which follows, 2) practically, invariable value
of energy of the accelerated test bunch when changing a
number of drive bunches. For parameters of numerical
experiment, the energy gain of test bunch increases at
stage of linear growth by 2.76 time for 4 drive bunches
in comparison with single drive bunch.
For the resonator the stages of linear growth of ener-
gy and constant value of energy of the accelerated test
bunch when increasing in a number of bunches of drive
sequence have repeated in pairs three times when using
for wakefield excitation up to fifty drive bunches. At
that the step growth of electron energy of test bunch is
observed. Thus the maximum of energy gain of test
bunch electrons increases by 5.29 times for 44 drive
bunches in comparison with single drive bunch.
When injecting drive bunches into wakefield accelerat-
ing system plasma electrons and ions are lost from system
so much more strongly, than more bunches are injected in
system that leads to change of its frequency characteristics
and violation of resonance in system. Therefore to in-
crease energy gain of test bunch it is necessary: either to
create in system of condition of additional generation of
plasma during the injection process, or to carry out non-
periodic injection of bunches, changing interval be-
tween bunches with growth of their number.
b a
d
c
ISSN 1562-6016. ВАНТ. 2018. №3(115) 57
ACKNOWLEDGMENT
Work supported by NAS of Ukraine program “Per-
spective investigations on plasma physics, controlled
thermonuclear fusion and plasma technologies”, project
P-1/63-2017 “Wakefield acceleration of electrons in
multi-zone dielectric and plasma-dielectric structures”.
REFERENCES
1. I. Blumenfeld, C.E. Clayton, F.-J. Decker, et al. En-
ergy doubling of 42 GeV electrons in a metre-scale
plasma wakefield accelerator // Nature. 2007, v. 445,
p. 741.
2. A.K. Beresin, Ya.B. Fainberg, L.I. Bolotin,
A.M. Egorov, V.A. Kiselev. Experimental investiga-
tion of interaction of the modulated relativistic
bunches with plasma // Pis'ma v ZhJeTF. 1971,
v. 13, p. 498-503 (in Russian).
3. A.K. Beresin, Ya.B. Fainberg, V.A. Kiselev,
A.F. Linnik, V.V. Uskov, V.A. Balakirev,
I.N. Onishchenko, G.L. Sidel’nikov, G.V. Sotnikov.
Wake-field excitation in a plasma by pulse of rela-
tivistic electrons containing of controlled number of
short bunches // Plasma Physics. 1994, v. 20,
№ 7, 8, p. 663-670.
4. K. Nakajima. Plasma wake-field accelerator driven
by a train of multiple bunches // Particle Accelera-
tors. 1990, v. 32, p. 209-218.
5. G.V. Sotnikov, R.R. Kniaziev, O.V. Manuilenko, et
al. Analytical and numerical studies of underdense
and overdense regimes in plasma-dielectric wakefield
accelerators // NIM. 2014, v. A 740, p. 124-129.
6. R.R. Kniaziev, O.V. Manuilenko, P.I. Markov, et al.
Focusing of electron and positron bunches in plas-
ma-dielectric wakefield accelerators // Problems of
Atomic Science and Technology. Series “Plasma
Electronics and New Methods of Acceleration”.
2013, № 4, p. 84-89.
7. P.I. Markov, R.R. Kniaziev, I.N. Onishchenko,
G.V. Sotnikov. Focusing of electron bunches in the
plasma-dielectric rectangular slowing-down struc-
ture // Problems of Atomic Science and Technology.
2016, № 3(103), p. 57-61.
8. G.V. Sotnikov, I.N. Onishchenko, T.C. Marshall. 3D
Analysis of Wakefield Excitation in a Dielectric
Loaded Rectangular Resonator, in Advanced Accel-
erator Concepts / M. Conde and C. Eyberger eds. //
AIP Conference Proceedings. 2006, p. 888-894.
Article received 28.02.2018
СРАВНИТЕЛЬНЫЙ АНАЛИЗ УСКОРЕНИЯ ТЕСТОВОГО ЭЛЕКТРОННОГО СГУСТКА
ПОСЛЕДОВАТЕЛЬНОСТЬЮ СГУСТКОВ В ДИЭЛЕКТРИЧЕСКОМ ВОЛНОВОДЕ
И РЕЗОНАТОРЕ, ЗАПОЛНЕННОМ ПЛАЗМОЙ
П.И. Марков, И.Н. Онищенко, Г.В. Сотников
Представлены результаты численного моделирования ускорения тестового сгустка последовательностью
релятивистских электронных сгустков в плазменно-диэлектрической цилиндрической замедляющей струк-
туре для случаев открытого и закрытого проводящей сеткой выходного торца структуры. Входной торец
был закрыт проводящей сеткой. Начальные размеры и энергия всех сгустков были одинаковыми. Расстояние
между сгустками последовательности равнялось длине волны электромагнитного поля в структуре. Тесто-
вый сгусток следовал за последним сгустком последовательности. Исследовалось ускорение тестового
сгустка при изменении количества сгустков последовательности. Мы обнаружили, что для волновода
наблюдаются две стадии: 1) линейный рост энергии ускоренного тестового сгустка с увеличением количе-
ства сгустков драйверной последовательности, за которым следует 2) практически, неизменное значение
энергии сгустка при изменении количества драйверных сгустков. Для резонатора отмеченные две стадии
линейного роста энергии и постоянного значения энергии тестового сгустка с увеличением количества
сгустков драйверной последовательности повторяются попарно несколько раз. При определённом количе-
стве сгустков в резонаторе можно получить существенно большее ускорение, чем в волноводе.
ПОРІВНЯЛЬНИЙ АНАЛІЗ ПРИСКОРЕННЯ ТЕСТОВОГО ЕЛЕКТРОННОГО ЗГУСТКА
ПОСЛІДОВНІСТЮ ЗГУСТКІВ У ДІЕЛЕКТРИЧНОМУ ХВИЛЕВОДІ ТА РЕЗОНАТОРІ,
ЗАПОВНЕНОМУ ПЛАЗМОЮ
П.І. Марков, І.М. Онiщенко, Г.В. Сотнiков
Представлені результати чисельного моделювання прискорення тестового згустка послідовністю реляти-
вістських електронних згустків у плазмово-діелектричній циліндричній сповільнюючiй структурі для випад-
ків відкритого й закритого провідною сіткою вихідного торця структури. Вхідний торець був закритий про-
відною сіткою. Початкові розміри й енергія всіх згустків були однаковими. Відстань між згустками послідо-
вності дорівнювала довжині хвилі електромагнітного поля в структурі. Тестовий згусток йшов за останнім
згустком послідовності. Досліджувалося прискорення тестового згустку при зміні кількості згустків послі-
довності. Ми виявили, що для хвилеводу спостерігаються дві стадії: 1) лінійне зростання енергії прискоре-
ного тестового згустка зі збільшенням кількості згустків драйверної послідовності, за яким іде 2) практично
незмінне значення енергії згустка при зміні кількості драйверних згустків. Для резонатора відзначені дві
стадії лінійного зростання енергії й незмінного значення енергії тестового згустка зі збільшенням кількості
згустків драйверної послідовності повторюються попарно кілька разів. При певній кількості згустків у резо-
наторі можна одержати суттєво більше прискорення, ніж у хвилеводі.
|