Possibility of the usage of active media with electron beams for ion acceleration
Brief analysis of publications, which have aroused considerable interest in physics of virtual cathode (VC) in connection with the problem of ions acceleration by electron beams (EB), results of distributed VC numeral simulation and variants of the systems in which the distributed VC can be used for...
Gespeichert in:
| Veröffentlicht in: | Вопросы атомной науки и техники |
|---|---|
| Datum: | 2008 |
| 1. Verfasser: | |
| Format: | Artikel |
| Sprache: | English |
| Veröffentlicht: |
Національний науковий центр «Харківський фізико-технічний інститут» НАН України
2008
|
| Schlagworte: | |
| Online Zugang: | https://nasplib.isofts.kiev.ua/handle/123456789/110768 |
| 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: | Possibility of the usage of active media with electron beams for ion acceleration / A.G. Lymar // Вопросы атомной науки и техники. — 2008. — № 6. — С. 141-143. — Бібліогр.: 10 назв. — англ. |
Institution
Digital Library of Periodicals of National Academy of Sciences of Ukraine| id |
nasplib_isofts_kiev_ua-123456789-110768 |
|---|---|
| record_format |
dspace |
| spelling |
Lymar, A.G. 2017-01-06T11:43:52Z 2017-01-06T11:43:52Z 2008 Possibility of the usage of active media with electron beams for ion acceleration / A.G. Lymar // Вопросы атомной науки и техники. — 2008. — № 6. — С. 141-143. — Бібліогр.: 10 назв. — англ. 1562-6016 PACS: 29.27.-a https://nasplib.isofts.kiev.ua/handle/123456789/110768 Brief analysis of publications, which have aroused considerable interest in physics of virtual cathode (VC) in connection with the problem of ions acceleration by electron beams (EB), results of distributed VC numeral simulation and variants of the systems in which the distributed VC can be used for acceleration of ions are presented. Приведені короткий аналіз публікацій, які визначили інтерес до фізики віртуального катода (ВК) у зв'язку з проблемою прискорення іонів електронними потоками (ЕП), результати чисельного моделювання поведінки розподіленого ВК і варіанти систем, в яких розподілений ВК може бути використаний для прискорення іонів. Приведены краткий анализ публикаций, которые определили интерес к физике виртуального катода (ВК) в связи с проблемой ускорения ионов электронными потоками (ЭП), результаты численного моделирования поведения распределенного ВК и варианты систем, в которых распределенный ВК может быть использован для ускорения ионов. en Національний науковий центр «Харківський фізико-технічний інститут» НАН України Вопросы атомной науки и техники Plasma electronics Possibility of the usage of active media with electron beams for ion acceleration Про можливість використання активних середовищ з електронними потоками для прискорення іонів О возможности использования активных сред с электронными потоками для ускорения ионов Article published earlier |
| institution |
Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| collection |
DSpace DC |
| title |
Possibility of the usage of active media with electron beams for ion acceleration |
| spellingShingle |
Possibility of the usage of active media with electron beams for ion acceleration Lymar, A.G. Plasma electronics |
| title_short |
Possibility of the usage of active media with electron beams for ion acceleration |
| title_full |
Possibility of the usage of active media with electron beams for ion acceleration |
| title_fullStr |
Possibility of the usage of active media with electron beams for ion acceleration |
| title_full_unstemmed |
Possibility of the usage of active media with electron beams for ion acceleration |
| title_sort |
possibility of the usage of active media with electron beams for ion acceleration |
| author |
Lymar, A.G. |
| author_facet |
Lymar, A.G. |
| topic |
Plasma electronics |
| topic_facet |
Plasma electronics |
| publishDate |
2008 |
| language |
English |
| container_title |
Вопросы атомной науки и техники |
| publisher |
Національний науковий центр «Харківський фізико-технічний інститут» НАН України |
| format |
Article |
| title_alt |
Про можливість використання активних середовищ з електронними потоками для прискорення іонів О возможности использования активных сред с электронными потоками для ускорения ионов |
| description |
Brief analysis of publications, which have aroused considerable interest in physics of virtual cathode (VC) in connection with the problem of ions acceleration by electron beams (EB), results of distributed VC numeral simulation and variants of the systems in which the distributed VC can be used for acceleration of ions are presented.
Приведені короткий аналіз публікацій, які визначили інтерес до фізики віртуального катода (ВК) у зв'язку з проблемою прискорення іонів електронними потоками (ЕП), результати чисельного моделювання поведінки розподіленого ВК і варіанти систем, в яких розподілений ВК може бути використаний для прискорення іонів.
Приведены краткий анализ публикаций, которые определили интерес к физике виртуального катода (ВК) в связи с проблемой ускорения ионов электронными потоками (ЭП), результаты численного моделирования поведения распределенного ВК и варианты систем, в которых распределенный ВК может быть использован для ускорения ионов.
|
| issn |
1562-6016 |
| url |
https://nasplib.isofts.kiev.ua/handle/123456789/110768 |
| citation_txt |
Possibility of the usage of active media with electron beams for ion acceleration / A.G. Lymar // Вопросы атомной науки и техники. — 2008. — № 6. — С. 141-143. — Бібліогр.: 10 назв. — англ. |
| work_keys_str_mv |
AT lymarag possibilityoftheusageofactivemediawithelectronbeamsforionacceleration AT lymarag promožlivístʹvikoristannâaktivnihseredoviŝzelektronnimipotokamidlâpriskorennâíonív AT lymarag ovozmožnostiispolʹzovaniâaktivnyhsredsélektronnymipotokamidlâuskoreniâionov |
| first_indexed |
2025-11-25T21:07:24Z |
| last_indexed |
2025-11-25T21:07:24Z |
| _version_ |
1850550317424312320 |
| fulltext |
POSSIBILITY OF THE USAGE OF ACTIVE MEDIA WITH ELECTRON
BEAMS FOR ION ACCELERATION
A.G. Lymar
National Science Center “Kharkov Institute of Physics and Technology”, Kharkov, Ukraine,
E-mail: lymar@kipt.kharkov.ua
Brief analysis of publications, which have aroused considerable interest in physics of virtual cathode (VC) in
connection with the problem of ions acceleration by electron beams (EB), results of distributed VC numeral simulation
and variants of the systems in which the distributed VC can be used for acceleration of ions are presented.
PACS: 29.27.-a
INTRODUCTION
The basic publications, which have defined direction
of our researches, are placed in [1-4]. Attractively simple
method of ion bunch (IB) acceleration has been offered in
[1]. IB, placed in rectilinear EB, excites electrostatic wave
and is accelerated by its field, providing the synchronous
moving with the accelerating wave. The transversal
stability of IB is provided by a volume charge of EB,
placed in the longitudinal magnetic field. Unfortunately, it
appeared that the excited wave cannot overcome repulsive
action of the IB volume charge in longitudinal direction,
and this method remained unrealized.
The results of ion acceleration in linear EB, generated
in plasma filled diodes [2], and EB injected into a neutral
gas are described [3,4]. Ions acceleration takes place, if
the current of EB exceeds the value at which VC appears.
Maximal energy of accelerated protons can exceed energy
of EB approximately in 10…20 times. This ratio
practically does not rely from the EB energy in the range
from 100 eV to 2 MeV. Maximal energies of heavy ions
do not rely on multiple of their charge. The ions of
different masses have the same maximum speed.
In spite of numerous attempts to account for the process
of ions acceleration in EB, it is not formulated now.
Set forth above results allow doing the following
conclusions: 1. For providing of longitudinal stability of
accelerated IB it is needed: either to place IB in EB,
possessing amplifier properties (it will allow to decrease
the IB charge), or place IB in EB, where an accelerating
wave is already created, leaving for IB, if it is possible,
only function of synchronization of acceleration wave
motion (in definite limits); 2. The mechanism of ions
acceleration in EB is based on the VC properties; 2.1.
This mechanism of acceleration practically does not
depend on energy of EB; 2.2. Ions are accelerated by a
group.
THE VC FEATURES WHICH IT IS POSSOBLE
TO USE FOR ION ACCELERATION
The first to be described was VC for EB of the flat
geometry [5] is shown in Fig.1. Here all electrodes are
endless planes parallel to each other. Electrons are
accelerated in a gap cathode 1 - net 2 and are injected into a
drift space between net and collector 3. The Uk potentials is
attached between cathode and net. According to the theory
[5] the state of electron stream in the drift space is
determined by the dimensionless magnitude J=Jinj /Jd, where
Jinj – density of injected current and
( )
3 2
0 2
4 2
9 1 0
k
d
UeJ
m y y
ε=
−
.
In Fig.2 the dependence of potential in the middle
plane of the drift space from J is presented. As J increases
from zero to J < 8, all the electrons, injecting in the drift
space, cross it and are taken up by the collector. At J = 8
there is irreversible transition of beam to the state with
VC, where part of electrons in the drift space comes back
toward the net. After the origin the state with VC exists at
J > 4. AT J = 4 the state with VC irreversibly passes to
the state without VC. At the numeral simulation of the
state with VC was discovered [6], that the theoretical
results, presented in [5], must be specified: there is an
oscillations in the state with VC, and owing to their
presence VC disappears at 4<Jmin ≅ 5,8.
It should be noted the following features of the
dependence, shown in Fig. 2: 1) two states, different by
the size of potential, correspond to every value of J in the
hysteresis loop; 2) the least perturbation causes
considerable changes of the states of EP on the borders of
the hysteresis loop. It is given below, as these features can
be used for IB acceleration.
Fig.1. The chart of the explored device: 1 – cathode;
2 – net; 3 – collector. Net and collector are shorted out
Fig.2. The potential at the center of drift space versus
density of injected current
The behaviour in time of a next state of the system
(Fig.1) is of interest. Lets the state corresponding to some
value of J in the interval of hysteresis and the value of
potential on the high bound of hysteresis loop is present in
one semi plane, and the state corresponding to the same
value of J, but the value of potential on the low bound of
hysteresis loop in the other semi plane. The same distributed
structures behaviour is described in literature (see for ex.
[7]). In our case, generally speaking, a border between states
moves, there is absorption of one state by the other. There is
only one “equilibrium value” of J at the hysteresis interval
PROBLEMS OF ATOMIC SCIENCE AND TECHNOLOGY. 2008. № 6. 141
Series: Plasma Physics (14), p. 141-143.
mailto:lymar@kipt.kharkov.ua
such that a border between the states is at rest. The greater J
value differs from “equilibrium value”, the greater velocity
of a border movement. In our case, if J value more than
“equilibrium value”, the state with VC absorb the state
without VC. If J value less than “equilibrium value”, the
state without VC absorb the state with VC.
The set forth model has verified by the results of the
experiment [8] and numeral simulation [9]. The behaviors
of the border between the states are shown in Fig.3. In the
case (a) the state with VC absorb the state without VC, in
the case (b) the border between the states is immobile, in
the case (c) the state with VC absorbed by the state
without VC. There is the overfall of potential and
accordingly electric field at the border between the states.
This field may be used for IB accelerations.
a b c
Fig.3. The potential in the middle plane of the drift space
as a function of the x and t for the different
injecting EB density J: a) 7.88; b) 7.4; c) 5.85
Fig.4. Velocity the border between the states versus
the injecting EB density J
It is shown in Fig.4 that the velocity of the border
movement depends on J. It is allows providing IB
acceleration and synchronization of its moving with the
accelerating wave by the suitable selection of J
dependence from x coordinate.
The numeral simulation shows that there are two
modes of oscillation for EB of considered geometry:
oscillation with relatively large amplitude with the
frequency ν and relatively small amplitude with the
frequency 3ν [6,9]. In Fig.5 the border between the states
behavior is shown, when the state with the small
amplitude oscillation absorb the state without VC
(analogue of the variant (а) Fig.3). As is seen from Fig.5,
the border between the states constitutes the potential pit
allowing accelerating IB at absorption of the state without
VC by the state with VC.
If to assume that protons can be accelerated to the
highest border velocity (see Fig.4), the protons energy
will be more than 20 times greater than the energy of
electrons at injection.
Fig.5. The state with VC with small amplitude of
oscillation absorbs the state without VC
Fig.6. Scheme of the accelerating period:
1,1а – cathodes; 2 – nets; 3 – meeting electronic bunches
The foregoing properties of the hysteresis loop
borders allows to offer the method of IB acceleration
wherein the synchronism of an accelerating wave and IB
moving provides by IB [10].
The possible variant of accelerating period (AP) for
realization of the offered method is schematically
represented in Fig.6. AP is symmetric in relation to the
axes of x and y and contains cathodes 1, 1а and the nets 2.
The upper and lower nets have the same potential.
Potentials of cathodes 1 and 1а are different. It allows at
the limited emission capability of cathodes to form the
state with VC with periodically changing parameters
along the x axis. In particular, it is possible to create in the
central part of AP the VC state close to the left border of
the hysteresis loop. In this case it is possible to produce
substantial alteration of the state of stream and
accordingly electric fields in the central part UP by small
perturbation. IB can be such perturbation, entering in UP
along the x axis. The given below results are obtained in
supposition, that IB is the evenly charged bar endless
along the z axis. Section of the bar in the xy plane is
ellipse with semiaxes along the axes of x and y
accordingly 64 and 16 units. The IB charge have been
selected so that the change of the potential value, caused
by the IB presence did not exceed 25%.
a b
142
Fig.7. Distributing of potential and the IB charge a) in
the case of presence VC along all AP and b) in the case
of absence VC in the central part of AP
The initial distributing of potential in AP is shown in
Fig.7a. IB passes the initial half of AP without acceleration.
In Fig.7b distribution of potential after transition of central
part of EB in the state without VC. From Fig.7b it is visible
that the IB acceleration takes place on the exit part of AP.
The resulted cycle of acceleration will repeat oneself in
subsequent AP until the IB speed will not get around the
speed of the VC border movement.
Of particular interest is the influence of IB on the
speed of the VC border movement. IB speed influence on
the speed of the VC border movement qualitatively
presented in Fig.8a−d. In Fig.8a motion of the border
between the states in the absence of IB is given. In
Fig.8b,c IB moves with a speed which exceeds the border
speed presented in Fig.8a. In Fig.8d the case is given,
when IB already does not handle of the border moving.
It is entirely possible that the presence of the
synchronizing influence of IB on the VC border moving
allows to reduce tolerances on the parameters of
accelerating structure.
a b c d
Fig.8. Potential in the plane y=(y0+y1)/2 vs x and t; (x) IB position vs t
CONCLUSIONS
1. The described original methods of acceleration
meet the conditions, formulated in p.1 of Introduction.
2. The expected ratio of the energy of accelerated ions
to the energy of EB in the offered method exceeds the
values which have obtained in the higher quoted
experiments [2-4].
3 The maximum energy of ions must not rely on
multiple of their charge, and the ions of different masses
must have the same maximum velocity in the foregoing
variant of ion acceleration in mobile potential pit. The
same situation was observed in the experiments [2-4].
REFERENCES
1. V.I. Veksler. Coherent principle of acceleration of charged
particles // Proc.CERN Symp. 1956, v.1, p.80.
2. А.А. Plyutto, I.F. Kvartshava, K.N. Kervalidze. Spark
source of multicharge ions // Atomic Energy. 1957, v.3,
p.153.
3. S. Graybill, J. Uglum. Observation of Energetic Ions from
Beam – Generated Plasma // J. Appl. Phys. 1970, v.41,
p.235.
4. J.S. Luse, H.L. Sahlin // IEEE Trans. 1973, v.NS-20, p.336.
5. V.R. Bursian, V.I. Pavlov // GRFHO. 1923, v.55, p.71.
6. C.K. Birdsall, W.B. Bridges. Space-Charge Instabilities in
Electron Diodes and Plasma Converters / J. Appl. Phys.
1961, v.32, №12, p.2611.
7. A.Vl. Gurevich, R.G. Mints. The localized waves in
heterogeneous mediums // UFN. 1984, v.142, p.61.
8. А.G. Lymar, A.V. Zvyagintsev, N.A. Khiznyak. About the
conduct of border of virtual emitter: Preprint. Kharkov:
NSC KIPT, KIPT 88-1, 1988.
9. А.G. Lymar. Waves of change of the states in an electronic
stream with the distributed virtual cathode // The physics of
plasma. 2003. v.29, № 1, p.85.
10. А.G. Lymar. About possibility of acceleration of ions by a
spatially periodic virtual cathode//PAST. Series “Plasma
Electronics and New Methods of Acceleration”(4). 2004,
№ 4, p.110.
О ВОЗМОЖНОСТИ ИСПОЛЬЗОВАНИЯ АКТИВНЫХ СРЕД С ЭЛЕКТРОННЫМИ ПОТОКАМИ ДЛЯ
УСКОРЕНИЯ ИОНОВ
А.Г. Лымарь
Приведены краткий анализ публикаций, которые определили интерес к физике виртуального катода (ВК) в
связи с проблемой ускорения ионов электронными потоками (ЭП), результаты численного моделирования
поведения распределенного ВК и варианты систем, в которых распределенный ВК может быть использован для
ускорения ионов.
ПРО МОЖЛИВІСТЬ ВИКОРИСТАННЯ АКТИВНИХ СЕРЕДОВИЩ З ЕЛЕКТРОННИМИ ПОТОКАМИ
ДЛЯ ПРИСКОРЕННЯ ІОНІВ
А.Г. Лимар
Приведені короткий аналіз публікацій, які визначили інтерес до фізики віртуального катода (ВК) у зв'язку з
проблемою прискорення іонів електронними потоками (ЕП), результати чисельного моделювання поведінки
розподіленого ВК і варіанти систем, в яких розподілений ВК може бути використаний для прискорення іонів.
143
О возможности ИсПОЛЬЗОВАНИЯ АКТИВНЫХ СРЕД с электронными потоками для ускорения ионов
А.Г. Лымарь
Про можливість Використання АКТИВНИХ СЕРЕДОВИЩ з електронними потоками для прискорення іонів
А.Г. Лимар
|