Hall ion source with ballistic and magnetic beam focusing
Reversible magnetic system for the circular Hall ion source with ion beam ballistic focusing was contrived and then investigated both theoretically and experimentally. It was shown that simultaneous application of ballistic and reversible magnetic focusing systems allows achieving ion beam compressi...
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| Veröffentlicht in: | Вопросы атомной науки и техники |
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| Datum: | 2008 |
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Національний науковий центр «Харківський фізико-технічний інститут» НАН України
2008
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| Zitieren: | Hall ion source with ballistic and magnetic beam focusing / A.A. Bizyukov, A.I. Girka, K.N. Sereda, A.V. Nazarov, E.V. Romaschenko // Вопросы атомной науки и техники. — 2008. — № 6. — С. 174-176. — Бібліогр.: 2 назв. — англ. |
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Digital Library of Periodicals of National Academy of Sciences of Ukraine| _version_ | 1859755982064713728 |
|---|---|
| author | Bizyukov, A.A. Girka, A.I. Sereda, K.N. Nazarov, A.V. Romaschenko, E.V. |
| author_facet | Bizyukov, A.A. Girka, A.I. Sereda, K.N. Nazarov, A.V. Romaschenko, E.V. |
| citation_txt | Hall ion source with ballistic and magnetic beam focusing / A.A. Bizyukov, A.I. Girka, K.N. Sereda, A.V. Nazarov, E.V. Romaschenko // Вопросы атомной науки и техники. — 2008. — № 6. — С. 174-176. — Бібліогр.: 2 назв. — англ. |
| collection | DSpace DC |
| container_title | Вопросы атомной науки и техники |
| description | Reversible magnetic system for the circular Hall ion source with ion beam ballistic focusing was contrived and then investigated both theoretically and experimentally. It was shown that simultaneous application of ballistic and reversible magnetic focusing systems allows achieving ion beam compression from initial diameter of 100 mm to the 1 mm diameter in a plane of the crossover.
Запропоновано, теоретично й експериментально досліджено реверсивну магнітну систему для холівського джерела з балістичним фокусуванням іонного пучка. Показано, що одночасне застосування балістичного й реверсивного магнітного фокусування іонного пучка дозволяє досягти компресії іонного пучка з початкового діаметра 100 мм до діаметра в площині кросовера 1 мм.
Предложена, теоретически и экспериментально исследована реверсивная магнитная система для холловского источника с баллистической фокусировкой ионного пучка. Показано, что совместное применение баллистической и реверсивной магнитной фокусировки ионного пучка позволяет достичь компрессии ионного пучка с начального диаметра 100 мм до диаметра в плоскости кроссовера 1 мм.
|
| first_indexed | 2025-12-02T01:10:25Z |
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HALL ION SOURCE WITH BALLISTIC AND MAGNETIC BEAM
FOCUSING
A.A. Bizyukov, A.I. Girka, K.N. Sereda, A.V. Nazarov*, E.V. Romaschenko
V.N.Karazin Kharkiv National University, 61077 Ukraine, e-mail:
GIRKA_OLEKSIY@MAIL.RU;
*MATI, Moscow, Russia
Reversible magnetic system for the circular Hall ion source with ion beam ballistic focusing was contrived and then
investigated both theoretically and experimentally. It was shown that simultaneous application of ballistic and reversible
magnetic focusing systems allows achieving ion beam compression from initial diameter of 100 mm to the 1 mm
diameter in a plane of the crossover.
PACS 52.80-s
1. INTRODUCTION
Gas discharge plasma is widely used in scientific
research, technique and technology as a source of intense
flows of charged particles [1, 2].
The problem of enhancing the density of electric
current in compact sources of ion flows always was of an
interest for the further development of plasma
technologies. One kind of such type modifications is
application of focusing.
Objective of this paper is designing and studying the
Hall ion source with ballistic focusing and achieving high
density of beam current and high power density within the
crossover plane. This problem is urgent, e.g., for
modeling the plasma-wall interaction in fusion devices.
2. BALLISTIC FOCUSING OF ION BEAM
2.1. MODIFICATION OF HALL ACCELERATOR
DESIGN FOR BALLISTIC FOCUSING OF ION
BEAM
If the method of ballistic focusing is used for
enhancing the beam current density then the geometric
coefficient of compression is equal (see Fig.1):
Gj=
a
sinR8 2 α . (1)
For the geometrical values which are typical for our
experimental conditions the coefficient of compression is
equal Gj=171.
Square of the crossover is expected to be S(crossover)
=3,45 mm2. In the Hall ion source, the beam current uses
to be up to 200 mA while the average ion energy is 1 keV.
Due to decreasing the square of the beam we expect to get
the beam density jcrossover=5,79 A/cm2. The latter is rather
high power per unit of square P=j εib=116 MW/m2.
To realize the ballistic focusing, usual plane cathode
and anode were replaced by the new ones of special shape
(Fig.1(d)) with channels which provided the producing of
cone-like beam (Fig.2).
The experiments were carried out under the discharge
voltage (1,5 ÷ 5) kV. Electric current in the magnetic coils
was varied from 0,7 up to 3 А, what corresponded to
maximum of magnetic field strength in the discharge gap
900 – 3300 Oe. The pressure in the work chamber was
(4 ÷ 5)10− 4 Тоrr. Argon was used as a working gas.
The experiments showed that the beam diameter in
crossover d increased with increase in the magnetic field
strength and decrease in the discharge voltage, and it did
not depend on the gas pressure and the beam current
(Fig.3.).
Analysis of the experimental data gives the value of
power n by U that in average is close to (−1/2).
а b
c
d
Fig. 1. Model of the beam ballistic focusing (а), its
geometric parameters (b), original hardware (c),
developed hardware (d)
Minimum diameter of the beam in the plane of
crossover obtained due to the utilization of ballistic
focusing reached 1.5 сm. Thus the ballistic focusing itself
does not produce ideal cone-like beam in Hall source
(Fig. 2).
Fig.2. Conditions of weak magnetic field and high
discharge voltage
174 PROBLEMS OF ATOMIC SCIENCE AND TECHNOLOGY. 2008. № 6.
Series: Plasma Physics (14), p. 174-176.
d
d
a
α
R
mailto:girka_oleksiy@mail.ru
0.0 0.5 1.0 1.5 2.0
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
d, cm
I/U1/2
Fig.3. The beam internal diameter in the plane of
crossover versus the electric current in the coils of the
source magnetic system and the discharge voltage
3. ESTIMATION OF ION DYNAMICS
Stages of ion motion in the system were considered.
Ion produced in the discharge gap finds itself in the gap of
the magnetic circuit with the velocity caused by the
discharge voltage. In the gap of the magnetic circuit, the
ion moves in the transversal radial magnetic field (Fig.4)
Fig.4. Qualitative distribution of the magnetic field
strength in the Hall source
and gets azimuthal acceleratіon caused by Lorentz force.
After leaving the zone where the magnetic field exists, the
ion keeps the transverse velocity that can prevent
successful ion flow convergence. Typical length of the
magnetic field zone is l1≈2 cm and Larmor radius is ρ
L=10 cm. Note that
ρL>> l1. (2)
Overall deviation of the ion trajectory from the point
of focus is given by the following expression:
yΣ=
Z
2
1Hi
2
l
υ
ω
+
Z
1Hi Ll
υ
ω
=
L
1Ll
ρ ~ U
H
. (3)
The expression (3) shows the main problem, viz, the
transversal pulse obtained by the ion at the short distance
l1 retains the same at the long distance L. To improve the
focusing, it was proposed to compensate the transversal
pulse by the magnetic field of opposite direction (sign),
i.e. to use the magnetic system with reversible magnetic
field in the Hall ion source (Fig.5). In this case, after
leaving the zone of the magnetic field the beam has the
deviation along y:
y(l2)=
Z
2
11Hi
2
l
υ
ω
+ωHi1l1
Z
2l
υ −
Z
2
22Hi
2
l
υ
ω
. (4)
Fig.5. Qualitative distribution of the magnetic
field strength in the reversible system
For our purposes, it would be ideally if υy2(l2)=0, i.e. ω
Hi1l1=ωHi2l2 . From physical point of view this means the
equality of magnetic fluxes, i.e. symmetric reversible
magnetic configuration. In this case the beam deviation
takes the form:
y(l2)=
Z
211Hi ll
υ
ω
=
1L
21ll
ρ . (5)
To get maximum focusing of the ion beam one needs
minimum typical lengths of the zones of the reversible
magnetic field.
4. HALL SOURCE WITH REVERSIBLE
MAGNETIC SYSTEM AND BALLISTIC
FOCUSING OF ION BEAM
Design of the source with both ballistic and magnetic
focusing is presented in the Fig.6.
Calculations of the ion deviation from the ballistic
trajectory for the conditions of our experiment (Fig.7)
give 0,1 cm. We succeeded in reaching the best results in
focusing the ion beam in the case of optimal magnetic
field in the coils. For our steady magnets which produce
the reversible magnetic field I(coil)=0.4 A and the highest
discharge voltage Udischrge=6 kV.
Fig.6. Hall ion source with ballistic and magnetic beam
focusing
Fig.7. Ion trajectory along which the magnetic field
strength distribution was found. In the figure:
(1) – first magnetic circuit for ballistic focusing,
(2) – second magnetic circuit for magnetic focusing
175
Z
1l L
y,H
Z
1l L
y,H
2l
1B
2B
0 10 20 30 40 50 60 70
-0.2
-0.1
0.0
0.1
0.2
0.3
0.4
0.5
0.6
мм,x
3
0
10
B
B ×
Fig. 8
The magnetic field distribution along the ion trajectory is
presented in Fig. 8.
For such limiting conditions the ion beam has internal
diameter in the plane of crossover less than the width of the
Hall source gap. (Fig. 9) For the parameters of high discharge
voltage and low current magnetic field coil the coefficient of
compression is equal GJ=33 and the power density is equal
P=21 MW/m2.
Fig.9.
The dependence of the ion beam internal diameter in the
plane of crossover on the given variable is presented in
the Fig.10. With taking into account the saturation of the
magnetic circuit this curve corresponds to theoretical
predictions good.
0.00 0.02 0.04 0.06 0.08
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
d,
c
m
U
)coil(I
Fig. 10
CONCLUSIONS
In this paper, it is shown both experimentally and
theoretically, that eigen magnetic field of the annular Hall
ion source prevents the ballistic formation of the cone
beam with high density of the current in the plane of
crossover.
Reversible magnetic system is proposed and studied
both theoretically and experimentally for Hall source with
ballistic focusing of ion beam. Joint utilization of ballistic
and reversible magnetic focusing of ion beam is shown to
allow reaching the compression of ion annular beam with
the thickness of 2 mm from initial diameter 100 mm to the
circle with internal diameter about 1 mm in the plane of
crossover.
A. Girka thanks to Association of alumni, professors
and friends of Kharkiv University for the support.
REFERENCES
1. A.I. Morozov. Introduction to Plasma Dynamics /
2nd edition improved and supplemented.
Moscow: “Physmatlit”, 2008.
2. U.S. Patent #US 2008/0191629 A1, Int. Cl. H01J
27/00, U.S. Cl. 315/11.61; 315/11.21. Focused
Anode Layer Ion Source With Converging and
Charge Compensated Beam
(FALCON) / M. Gutkin, A. Bizyukov, V. Sleptsov,
I. Bizyukov, K. Sereda.
Article received 22.09.08.
ХОЛЛОВСКИЙ ИСТОЧНИК ИОНОВ С БАЛЛИСТИЧЕСКОЙ И МАГНИТНОЙ ФОКУСИРОВКОЙ
ПУЧКА
А.А. Бизюков, К.Н. Середа, А.И. Гирка, А.В. Назаров, Е.В. Ромащенко
Предложена, теоретически и экспериментально исследована реверсивная магнитная система для
холловского источника с баллистической фокусировкой ионного пучка. Показано, что совместное применение
баллистической и реверсивной магнитной фокусировки ионного пучка позволяет достичь компрессии ионного
пучка с начального диаметра 100 мм до диаметра в плоскости кроссовера 1 мм.
ХОЛІВСЬКЕ ДЖЕРЕЛО ІОНІВ З БАЛІСТИЧНИМ І МАГНІТНИМ ФОКУСУВАННЯМ ПУЧКА
О.А. Бізюков, К.М. Середа, О.І. Гірка, О.В. Назаров, О.В. Ромащенко
Запропоновано, теоретично й експериментально досліджено реверсивну магнітну систему для холівського
джерела з балістичним фокусуванням іонного пучка. Показано, що одночасне застосування балістичного й
реверсивного магнітного фокусування іонного пучка дозволяє досягти компресії іонного пучка з початкового
діаметра 100 мм до діаметра в площині кросовера 1 мм.
176
|
| id | nasplib_isofts_kiev_ua-123456789-110977 |
| institution | Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| issn | 1562-6016 |
| language | English |
| last_indexed | 2025-12-02T01:10:25Z |
| publishDate | 2008 |
| publisher | Національний науковий центр «Харківський фізико-технічний інститут» НАН України |
| record_format | dspace |
| spelling | Bizyukov, A.A. Girka, A.I. Sereda, K.N. Nazarov, A.V. Romaschenko, E.V. 2017-01-07T15:42:17Z 2017-01-07T15:42:17Z 2008 Hall ion source with ballistic and magnetic beam focusing / A.A. Bizyukov, A.I. Girka, K.N. Sereda, A.V. Nazarov, E.V. Romaschenko // Вопросы атомной науки и техники. — 2008. — № 6. — С. 174-176. — Бібліогр.: 2 назв. — англ. 1562-6016 PACS 52.80-s https://nasplib.isofts.kiev.ua/handle/123456789/110977 Reversible magnetic system for the circular Hall ion source with ion beam ballistic focusing was contrived and then investigated both theoretically and experimentally. It was shown that simultaneous application of ballistic and reversible magnetic focusing systems allows achieving ion beam compression from initial diameter of 100 mm to the 1 mm diameter in a plane of the crossover. Запропоновано, теоретично й експериментально досліджено реверсивну магнітну систему для холівського джерела з балістичним фокусуванням іонного пучка. Показано, що одночасне застосування балістичного й реверсивного магнітного фокусування іонного пучка дозволяє досягти компресії іонного пучка з початкового діаметра 100 мм до діаметра в площині кросовера 1 мм. Предложена, теоретически и экспериментально исследована реверсивная магнитная система для холловского источника с баллистической фокусировкой ионного пучка. Показано, что совместное применение баллистической и реверсивной магнитной фокусировки ионного пучка позволяет достичь компрессии ионного пучка с начального диаметра 100 мм до диаметра в плоскости кроссовера 1 мм. A. Girka thanks to Association of alumni, professors and friends of Kharkiv University for the support. en Національний науковий центр «Харківський фізико-технічний інститут» НАН України Вопросы атомной науки и техники Low temperature plasma and plasma technologies Hall ion source with ballistic and magnetic beam focusing Холівське джерело іонів з балістичним і магнітним фокусуванням пучка Холловский источник ионов с баллистической и магнитной фокусировкой пучка Article published earlier |
| spellingShingle | Hall ion source with ballistic and magnetic beam focusing Bizyukov, A.A. Girka, A.I. Sereda, K.N. Nazarov, A.V. Romaschenko, E.V. Low temperature plasma and plasma technologies |
| title | Hall ion source with ballistic and magnetic beam focusing |
| title_alt | Холівське джерело іонів з балістичним і магнітним фокусуванням пучка Холловский источник ионов с баллистической и магнитной фокусировкой пучка |
| title_full | Hall ion source with ballistic and magnetic beam focusing |
| title_fullStr | Hall ion source with ballistic and magnetic beam focusing |
| title_full_unstemmed | Hall ion source with ballistic and magnetic beam focusing |
| title_short | Hall ion source with ballistic and magnetic beam focusing |
| title_sort | hall ion source with ballistic and magnetic beam focusing |
| topic | Low temperature plasma and plasma technologies |
| topic_facet | Low temperature plasma and plasma technologies |
| url | https://nasplib.isofts.kiev.ua/handle/123456789/110977 |
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