Dependence of wakefield excitation in plasma by non-resonant sequence of electron bunches on their lengths

The present paper describes the results of numerical simulation (using 2d3v code LCODE) of the regime, when the wakefield is excited at maximum growth rate in the plasma by a nonresonant sequence of relativistic electron bunches. As a result, the wakefield increases approximately in steps. The paper...

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Published in:Вопросы атомной науки и техники
Date:2021
Main Authors: Bondar, D.S., Boychenko, A.P., Maslov, V.I., Onishchenko, I.N., Ovsiannikov, R.T.
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Language:English
Published: Національний науковий центр «Харківський фізико-технічний інститут» НАН України 2021
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Online Access:https://nasplib.isofts.kiev.ua/handle/123456789/195256
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Cite this:Dependence of wakefield excitation in plasma by non-resonant sequence of electron bunches on their lengths / D.S. Bondar, A.P. Boychenko, V.I. Maslov, I.N. Onishchenko, R.T. Ovsiannikov // Problems of Atomic Science and Technology. — 2021. — № 4. — С. 65-69. — Бібліогр.: 28 назв. — англ.

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Digital Library of Periodicals of National Academy of Sciences of Ukraine
id nasplib_isofts_kiev_ua-123456789-195256
record_format dspace
spelling Bondar, D.S.
Boychenko, A.P.
Maslov, V.I.
Onishchenko, I.N.
Ovsiannikov, R.T.
2023-12-03T15:58:22Z
2023-12-03T15:58:22Z
2021
Dependence of wakefield excitation in plasma by non-resonant sequence of electron bunches on their lengths / D.S. Bondar, A.P. Boychenko, V.I. Maslov, I.N. Onishchenko, R.T. Ovsiannikov // Problems of Atomic Science and Technology. — 2021. — № 4. — С. 65-69. — Бібліогр.: 28 назв. — англ.
1562-6016
PACS: 29.17.+w; 41.75.Lx
DOI: https://doi.org/10.46813/2021-134-065
https://nasplib.isofts.kiev.ua/handle/123456789/195256
The present paper describes the results of numerical simulation (using 2d3v code LCODE) of the regime, when the wakefield is excited at maximum growth rate in the plasma by a nonresonant sequence of relativistic electron bunches. As a result, the wakefield increases approximately in steps. The paper gives the parameters, at which this regime is achieved. It is shown that for smaller bunch radii, the amplitude of the excited wakefield is larger. At long lengths of the bunches, the amplitude of the wakefield is larger, in contrast to the excitation by the resonant sequence of bunches.
Описані результати чисельного моделювання (з використанням коду 2d3v LCODE) режиму, коли кільватерне поле збуджується з максимальною швидкістю росту в плазмі нерезонансною послідовністю релятивістських електронних згустків. У результаті кільватерне поле збільшується приблизно поступово. Наведено параметри, при яких досягається цей режим. Показано, що для менших радіусів згустка амплітуда збудженого кільватерного поля більше. При великих довжинах згустків амплітуда кільватерного поля більше, на відміну від режиму збудження резонансною послідовністю згустків.
Описаны результаты численного моделирования (с использованием кода 2d3v LCODE) режима, когда кильватерное поле возбуждается с максимальной скоростью роста в плазме нерезонансной последовательностью релятивистских электронных сгустков. В результате кильватерное поле увеличивается примерно ступенчато. Приведены параметры, при которых достигается этот режим. Показано, что для меньших радиусов сгустка амплитуда возбужденного кильватерного поля больше. При больших длинах сгустков амплитуда кильватерного поля больше в отличие от режима возбуждения резонансной последовательностью сгустков.
The study is supported by the National Research Foundation of Ukraine under the program “Leading and Young Scientists Research Support” (project # 2020.02/0299).
en
Національний науковий центр «Харківський фізико-технічний інститут» НАН України
Вопросы атомной науки и техники
New methods of charged particles acceleration
Dependence of wakefield excitation in plasma by non-resonant sequence of electron bunches on their lengths
Залежність резонансного збудження кільватерного поля в плазмі нерезонансною послідовністю електронних згустків від їх довжин
Зависимость резонансного возбуждения кильватерного поля в плазме нерезонансной последовательностью электронных сгустков от их длин
Article
published earlier
institution Digital Library of Periodicals of National Academy of Sciences of Ukraine
collection DSpace DC
title Dependence of wakefield excitation in plasma by non-resonant sequence of electron bunches on their lengths
spellingShingle Dependence of wakefield excitation in plasma by non-resonant sequence of electron bunches on their lengths
Bondar, D.S.
Boychenko, A.P.
Maslov, V.I.
Onishchenko, I.N.
Ovsiannikov, R.T.
New methods of charged particles acceleration
title_short Dependence of wakefield excitation in plasma by non-resonant sequence of electron bunches on their lengths
title_full Dependence of wakefield excitation in plasma by non-resonant sequence of electron bunches on their lengths
title_fullStr Dependence of wakefield excitation in plasma by non-resonant sequence of electron bunches on their lengths
title_full_unstemmed Dependence of wakefield excitation in plasma by non-resonant sequence of electron bunches on their lengths
title_sort dependence of wakefield excitation in plasma by non-resonant sequence of electron bunches on their lengths
author Bondar, D.S.
Boychenko, A.P.
Maslov, V.I.
Onishchenko, I.N.
Ovsiannikov, R.T.
author_facet Bondar, D.S.
Boychenko, A.P.
Maslov, V.I.
Onishchenko, I.N.
Ovsiannikov, R.T.
topic New methods of charged particles acceleration
topic_facet New methods of charged particles acceleration
publishDate 2021
language English
container_title Вопросы атомной науки и техники
publisher Національний науковий центр «Харківський фізико-технічний інститут» НАН України
format Article
title_alt Залежність резонансного збудження кільватерного поля в плазмі нерезонансною послідовністю електронних згустків від їх довжин
Зависимость резонансного возбуждения кильватерного поля в плазме нерезонансной последовательностью электронных сгустков от их длин
description The present paper describes the results of numerical simulation (using 2d3v code LCODE) of the regime, when the wakefield is excited at maximum growth rate in the plasma by a nonresonant sequence of relativistic electron bunches. As a result, the wakefield increases approximately in steps. The paper gives the parameters, at which this regime is achieved. It is shown that for smaller bunch radii, the amplitude of the excited wakefield is larger. At long lengths of the bunches, the amplitude of the wakefield is larger, in contrast to the excitation by the resonant sequence of bunches. Описані результати чисельного моделювання (з використанням коду 2d3v LCODE) режиму, коли кільватерне поле збуджується з максимальною швидкістю росту в плазмі нерезонансною послідовністю релятивістських електронних згустків. У результаті кільватерне поле збільшується приблизно поступово. Наведено параметри, при яких досягається цей режим. Показано, що для менших радіусів згустка амплітуда збудженого кільватерного поля більше. При великих довжинах згустків амплітуда кільватерного поля більше, на відміну від режиму збудження резонансною послідовністю згустків. Описаны результаты численного моделирования (с использованием кода 2d3v LCODE) режима, когда кильватерное поле возбуждается с максимальной скоростью роста в плазме нерезонансной последовательностью релятивистских электронных сгустков. В результате кильватерное поле увеличивается примерно ступенчато. Приведены параметры, при которых достигается этот режим. Показано, что для меньших радиусов сгустка амплитуда возбужденного кильватерного поля больше. При больших длинах сгустков амплитуда кильватерного поля больше в отличие от режима возбуждения резонансной последовательностью сгустков.
issn 1562-6016
url https://nasplib.isofts.kiev.ua/handle/123456789/195256
citation_txt Dependence of wakefield excitation in plasma by non-resonant sequence of electron bunches on their lengths / D.S. Bondar, A.P. Boychenko, V.I. Maslov, I.N. Onishchenko, R.T. Ovsiannikov // Problems of Atomic Science and Technology. — 2021. — № 4. — С. 65-69. — Бібліогр.: 28 назв. — англ.
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first_indexed 2025-11-26T01:39:54Z
last_indexed 2025-11-26T01:39:54Z
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fulltext ISSN 1562-6016. ВАНТ. 2021. № 4(134) 70 https://doi.org/10.46813/2021-134-070 PLASMA LENS FOR ELECTRON AND POSITRON BEAMS D.S. Bondar1,2, V.I. Maslov1,2, I.N. Onishchenko1, R.T. Ovsiannikov2 1National Science Center “Kharkov Institute of Physics and Technology”, Kharkiv, Ukraine; 2V.N. Karazin Kharkiv National University, Kharkiv, Ukraine E-mail: vmaslov@kipt.kharkov.ua Focusing of both electron and positron bunches in electron-positron collider is necessary. When long elec- tron/positron bunch is injected into the plasma, the focusing force is not uniform but oscillated. It is shown that a long positron bunch after focusing is destroyed faster than an electron bunch due to betatron and plasma oscillations. PACS: 29.17.+W; 41.75.LX INTRODUCTION Plasma wakefield accelerators provide an extremely high accelerating gradient [1 - 13], long sequence focus- ing and large transformer ratio obtaining [14 - 23], reso- nant wakefield excitation by a nonresonant sequence of electron bunches [24, 25]. Focusing of relativistic elec- tron bunches by wakefield, excited in the plasma, is important previously studied effect [26 - 37]. Mecha- nism of focusing in the plasma, by which all bunches of a sequence are focused identically and uniformly, is proposed and investigated by numerical simulation in [14 - 16]. The plasma lens for long relativistic electron and positron bunch focusing is studied in this paper by nu- merical simulation using code lcode [38]. Unbounded non-magnetized homogeneous plasma is considered. The Gaussian ( 2cos A ) in longitudinal direction bunch (current profile) is considered. The purpose of this paper is to show by numerical simulation that one can achieve conditions of focusing of long relativistic electron and positron bunch. In this paper the authors present the results of numerical simu- lation on the focusing force distribution for long elec- tron and positron bunches. We use the cylindrical coordinate system ( , )r z . The time  is normalized to 1 pe  , all the distances and coor- dinate  – to 1 pec , the density  to the unperturbed plasma electron density, the beam current bI – to 3 / 17 kAmc e  , the fields – to /pemc e , where m is the electron mass, e is the electron charge, c is the speed of light, pe is the plasma electron frequency.  is the plasma wavelength. The simulation time is 160.1 pe . 5b  for all bunches. The length of all bunches is 8bL  . These normalisations are used also in the Fig- ures. The arrow on all Figures indicates the direction of movement of the bunches. We present the numerical simulation data on plasma wakefield excitation by a relativistic electron and posi- tron bunch, obtained with the 2.5D quasi-static code lcode. It treats the plasma as a cold electron fluid (mag- netohydrodynamics model), and the bunches as ensem- bles of macro-particles. Spatial step equals 10.1 pec . Time step for plasma electrons equals 10.1 pe . Time step for beam electrons equals 10.1 b pe  . Spatial dependences in selected points of observation are presented. RESULTS OF NUMERICAL SIMULATION At first, the excited field distribution, formed by long Gaussian electron bunch in the plasma (Fig. 1) is considered. Fig. 1. Spatial distribution of Gaussian bunch electron density  ,bn r (minus indicates to the electron bunches) at 5b  , 2 25z  , 0.1r  , maximum initial electron bunch current 30.6 10bI   In this case, a rather smooth electrons  ,en r (Fig. 2) density pit is formed in the plasma in the Gaus- sian bunch region. Fig. 2. Spatial distribution of plasma electron density  ,en r (corresponds to Fig. 1) In addition, smooth focusing force is observed in the region of the bunch (Fig. 3). First (approximately, during the first half of the simulation time), the focusing of the electron bunch is observed (Figs. 4-6). The centers of the bunches are subjected to the strongest focusing (see Fig. 5). t1 t1 ISSN 1562-6016. ВАНТ. 2021. № 4(134) 71 Fig. 3. Longitudinal distribution of focusing force  eF  (corresponds to Figs. 1, 2) Fig. 4. Spatial distribution of focused Gaussian bunch electron density  ,bn r Fig. 5. Longitudinal distribution of bunch electron density  ,b bn r r  : before focusing (a); after focusing (b) a b Fig. 6. Longitudinal distribution of bunch electron den- sity  , 0bn r  : before focusing (a); after focusing (b) Then (after approximately 1 130 40pe pet     ) beta- tron oscillations develop. Since the frequency of beta- tron oscillations for electrons of the bunch located at different radii is different, the bunch stratifies and the electrons of the bunch peripheral along the radius are defocused (Fig. 7). In general, the destruction of the bunch can be observed along the entire diameter. Fig. 7. Spatial distribution of Gaussian bunch electron density  ,bn r due to betatron and plasma oscillations Fig. 8. Spatial distribution of Gaussian bunch positron density  ,bn r From comparison Figs. 7 and 8 it can be seen that for the same time the positron bunch is destroyed more strongly than electron. From the beginning, oscillations are observed in the second part (after 30 / pec  ) of the plasma electron density pit (Fig. 9). Fig. 9. On-axis longitudinal distribution of plasma elec- tron density  , 0en r  (corresponds to Figs. 1, 2) Then oscillations are excited in the plasma electron density (Fig. 10). The development of oscillations can be seen on  rF  graph (Fig. 11). As a result, the bunch is modulated (see Fig. 12). a b ISSN 1562-6016. ВАНТ. 2021. № 4(134) 72 Fig. 10. Spatial distribution of plasma electron density  ,en r Fig. 11. Longitudinal distribution of focusing force  rF  Fig. 12. Longitudinal distribution of bunch electron density  ,b bn r r  at large (end of simulation) times In general, the destruction of the bunch is visible along the entire diameter. Thus, the inhomogeneity of the focusing force and the modulation of relativistic bunches of electrons and positrons during their propaga- tion in the plasma due to betatron and plasma oscilla- tions are shown. In addition, it has been shown that positron bunch is destroyed more strongly and faster than electron bunch. CONCLUSIONS A numerical simulation of the focusing of electron and positron bunches by a plasma lens is carried out. When a long electron/positron bunch is injected into the plasma, the resulting focusing force is not uniform, but oscillates. It was shown that a long bunch of positrons after focusing is destroyed faster than an electron bunch due to betatron and plasma oscillations. ACKNOWLEDGEMENTS The study is supported by the National Research Foundation of Ukraine under the program “Leading and Young Scientists Research Support” (project # 2020.02/0299). REFERENCES 1. E. Esarey, S. Sprangle, J. Krall, A. Ting. Overview of Plasma-Based Accelerator Concepts // IEEE Trans. Plasma Sci. 1996, v. PS-24(2), p. 252-88. 2. A.V. Brantov, T.Zh. Esirkepov, M. Kando, H. Ko- taki, V.Yu. Bychenkov, and S.V. Bulanov. Con- trolled electron injection into the wake wave using plasma density inhomogeneity // Phys. Plas. 2008, v. 15, p. 073111. 3. S. Lee, T. Katsouleas, R. Hemkel, and Mori. W2000 Simulations of a meter-long plasma wakefield accel- erator // Phys. Rev. E. 2000, v. 61(6), p. 7014-21. 4. N. Kumar, A. 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Маслов, И.Н. Онищенко, Р.Т. Овсянников Необходима фокусировка как электронных, так и позитронных сгустков в электрон-позитронных кол- лайдерах. При инжекции длинного сгустка электронов/позитронов в плазму образующаяся фокусирующая сила не однородна, а с некоторыми осцилляциями. Показано, что длинный позитронный сгусток после фо- кусировки разрушается быстрее, чем электронный сгусток за счет бетатронных колебаний и плазменных осцилляций. ПЛАЗМОВА ЛІНЗА ДЛЯ ЕЛЕКТРОННОГО І ПОЗИТРОННОГО ПУЧКІВ Д.С. Бондарь, В.І. Маслов, І.М. Онiщенко, Р.Т. Овсянніков Необхідне фокусування як електронних, так і позитронних згустків в електрон-позитронних колайдерах. При інжекції довгого згустка електронів/позитронів у плазму утворювана фокусуюча сила не однорідна, а з деякими осциляціями. Показано, що довгий позитронний згусток після фокусування руйнується швидше, ніж електронний згусток за рахунок бетатронних коливань і плазмових осциляцій.