Extraction of fusion relevant ion species from discharge of focused anode layer thruster
The modification of anode layer thruster, which utilizes the focusing with reversed magnetic field (FALCON ion source), has been investigated for operation with H, He and Ar working gases. Current efficiency was measured to be in the range of 30…40% for H and Ar ion beam, while for He gas it varies...
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| Опубліковано в: : | Вопросы атомной науки и техники |
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| Дата: | 2015 |
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Національний науковий центр «Харківський фізико-технічний інститут» НАН України
2015
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| Цитувати: | Extraction of fusion relevant ion species from discharge of focused anode layer thruster / O. Girka, O. Bizyukov, Yu. Kolyada, K. Sereda, I. Bizyukov // Вопросы атомной науки и техники. — 2015. — № 4. — С. 22-25. — Бібліогр.: 17 назв. — англ. |
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Digital Library of Periodicals of National Academy of Sciences of Ukraine| _version_ | 1860141487448129536 |
|---|---|
| author | Girka, O. Bizyukov, O. Kolyada, Yu. Sereda, K. Bizyukov, I. |
| author_facet | Girka, O. Bizyukov, O. Kolyada, Yu. Sereda, K. Bizyukov, I. |
| citation_txt | Extraction of fusion relevant ion species from discharge of focused anode layer thruster / O. Girka, O. Bizyukov, Yu. Kolyada, K. Sereda, I. Bizyukov // Вопросы атомной науки и техники. — 2015. — № 4. — С. 22-25. — Бібліогр.: 17 назв. — англ. |
| collection | DSpace DC |
| container_title | Вопросы атомной науки и техники |
| description | The modification of anode layer thruster, which utilizes the focusing with reversed magnetic field (FALCON ion source), has been investigated for operation with H, He and Ar working gases. Current efficiency was measured to be in the range of 30…40% for H and Ar ion beam, while for He gas it varies from 10 to 20%.
Досліджувалася модифікація прискорювача з анодним шаром з використанням фокусування реверсивним магнітним полем (іонне джерело FALCON) для застосування з воднем, гелієм та аргоном в якості робочих газів. Струм легких іонів не перевищував 12 мА, в той час як струм іонного пучка аргону сягав 25…65 мА. Виміряна струмова ефективність була в діапазоні 30...40% для водню та аргону, 10…20% для гелію.
Исследовалась модификация ускорителя с анодным слоем с использованием фокусировки реверсивным магнитным полем (ионный источник FALCON) для применения с рабочими газами водородом, гелием и аргоном. Ток легких ионов не превышал 12 мА, в то время как ток ионного пучка аргона достигал 25…65 мА. Измеренная токовая эффективность находилась в диапазоне 30...40% для водорода и аргона, 10…20% для гелия.
|
| first_indexed | 2025-12-07T17:49:44Z |
| format | Article |
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ISSN 1562-6016. ВАНТ. 2015. №4(98) 22
EXTRACTION OF FUSION RELEVANT ION SPECIES FROM
DISCHARGE OF FOCUSED ANODE LAYER THRUSTER
O. Girka1, O. Bizyukov1, Yu. Kolyada2, K. Sereda1, I. Bizyukov1
1V.N. Karazin Kharkiv National University, Kharkov, Ukraine;
2Mariupol State University, Mariupol, Ukraine
E-mail: ivan.bizyukov@karazin.ua
The modification of anode layer thruster, which utilizes the focusing with reversed magnetic field (FALCON ion
source), has been investigated for operation with H, He and Ar working gases. Current efficiency was measured to
be in the range of 30…40% for H and Ar ion beam, while for He gas it varies from 10 to 20%.
PACS: 79.20 Rf
INTRODUCTION
The progress and success of International Thermo-
nuclear Experimental Reactor (ITER) is tightly related
to problem of the plasma-facing materials (PFMs). In-
teracting with high particle and heat fluxes from edge
plasma, PFMs experience erosion and degradation, fuel
accumulation, etc [1, 2]. Therefore, the behavior of
plasma-facing materials under extreme conditions needs
to be investigated preliminary in order to provide the
database for development and design of plasma-facing
components (PFCs).
While few of the erosion mechanisms are well
known and could be predicted by existing theoretical
models [1, 3], many degradation and erosion effects
related to high heat and particle loads are under investi-
gations [4]. The main method of investigation of the
plasma-surface interaction effects is experimental mod-
eling. It requires the source of intense particle fluxes:
plasma devices, like Magnum-PSI [5], PISCES [6] or
NAGDIS [7]; ion sources, like HiFiT [8], FALCON [9]
or neutral beam sources [5].
Since plasma devices and most ion sources are ex-
pensive in operation and maintenance, the development
of compact device for small-scale labs is essential.
FALCON ion source has been developed to provide
fusion relevant heat and particle fluxes [9 - 12]. It is
based on design of closed drift thrusters (also known as
Hall thrusters), which are typically used as space pro-
pulsions [13], which should be simple in operation,
compact and provide high ion currents. However, pri-
mary working gas for space propulsions is xenon (Xe)
due to its high atomic mass and, consequently, the mo-
mentum, which can be provided to the satellite. Appli-
cation of FALCON ion source for fusion oriented mate-
rial research [14 - 17] requires its operation with fusion
relevant gases, like hydrogen (H), deuterium (D), heli-
um (He), argon (Ar).
The special feature of the FALCON ion source is
thin anode layer, which typical thickness is few milli-
meters. It consists of electrons drifting in the crossed
electric and magnetic field (this layer essentially gives
the name to the thrusters family), where all processes of
gas ionization and ion acceleration take place. The con-
finement of anode layer requires relatively strong mag-
netic field of several kilo Gauss. While Xe ions are
heavy and their trajectories are weakly bent by magnetic
field, the trajectories of light ions might be affected
stronger [11, 17], directing them to the cathodes of dis-
charge gap and focusing system. Even more, the mag-
netic field in FALCON ion source is responsible for the
focusing of the ion beam as well. As the result, signifi-
cant part of the ion beam current is lost inside the ion
source, which decreases the ion beam current delivered
to the target. Present work studies the operation of
FALCON ion source with fusion relevant species, like
H, He and Ar. Particular attention is paid to the opera-
tion conditions optimal for experimental modeling of
plasma-surface interactions.
1. EXPERIMENTAL
The principal design of the FALCON ion source is
presented in Fig. 1. The biased anode (1) and cathode at
the ground potential (2) form the discharge gap de-
signed to provide the drift of electron layer in crossed
E×B fields. Main ionizing processes and acceleration of
the ions occur within this electron drift layer.
Fig. 1. Schematic drawing of the FALCON ion source.
1 – anode; 2 – cathodes; 3 – magnetic focusing lens;
4 – magnetic field coils; 5 – magnetic circuit;
6 – the target placed in the H+ crossover plane;
7 – Hydrogen ions beam trajectory;
8 – impurities trajectory
The ion source has an ion focusing system consist-
ing of two parts. The first part is the ballistic focusing
system, consisting of tilted anode (1) and cathode (2); it
forms ion beam of the conical shape. The magnetic fo-
cusing system (3) focuses the ion beam further by can-
celling a momentum, which ions gain in the magnetic
field of the discharge gap. The reversed magnetic field
configuration is powered by two magnetic coils (4); the
magnetic circuit delivers the generated magnetic fluxes
to the respective gaps.
ISSN 1562-6016. ВАНТ. 2015. №4(98) 23
Steady-state magnetic coils (4) are connected in-
versely and deliver the magnetic fluxes through the
magnetic circuit (5) to the respective gaps. Varying the
electric current through the coils one can manipulate the
magnetic field fluxes and the size of the beam spot in
the crossover plane, where exposed target (6) should be
placed. While the trajectories of light ion species (7) can
be focused in the crossover plane, trajectories of heavier
ions, like oxygen, which are located further from the
central point (8).
In experiments three working gases were fed to the
gas inlet system of the source: H, He and Ar. The ion
beam current and the discharge current have been meas-
ured while range of voltage applied to the discharge gap
varied from 1 to 6 keV.
2. RESULTS AND DISCUSSION
Fig. 2 shows the measurements of ion beam currents
for H, He and Ar working gases fed to the source. The
pressure range of (2…4)·10-4 Torr has been maintained
as optimal for the operation of the source. The system
has been evacuated with turbomolecular pump with the
pumping speed of 1200 l/s. Higher pressure typically
results in higher ion beam current, however, the anode
layer thruster has upper limit for the pressure in the vac-
uum chamber. Exceeding the limit, discharge experi-
ence significant drop of the voltage with corresponding
increase of the ion beam and discharge current. These
parameters are typical for the magnetron regime with
the disruption of the focusing properties of the system.
Typically, ion beam current growth with the voltage
increasing, different types of working gas show differ-
ent dynamics. Hydrogen and argon ion beam currents
increase monotonically with increasing voltage and
pressure, while helium shows another dynamics (see
Fig. 2,b). In the voltage range from 1 to 2.5 keV, ion
beam current for lower pressure of 2·10-4 Torr exceeds
one for higher pressure of 4·10-4 Torr. This might be
related to the pumping efficiency of the helium or pro-
cesses inside the discharge gap.
Generally, the FALCON ion source generates singly
charged ions. Once ion is created, it is immediately ac-
celerated and removed from the ionization zone. How-
ever, there is no data on the number of atoms in the sin-
gle ion. Since it typical for noble gases, He and Ar ions
are monoatomic, while H ions may contain one, two or
three atoms per ion.
The current of the ion beam depends strongly on
species. For H and He ions, the current growth from
1 mA up to 6…12 mA depending on acceleration volt-
age and the pressure in the vacuum chamber. Current
for the beam of Ar ions shows much higher peak values
and broader range of variations: it starts from about
5 mA and increases up to 25…65 mA.
Present set of measurement does not take into ac-
count the errors originating from secondary electrons
and the electrons confined in the potential well of the
ion beam [12]. Ion-electron emission increases the
measured ion beam current. The electrons confined by
the potential of the ion beam decrease the measured ion
beam current, when collected by the target. Previous
studies [9] have shown that the deviation of the ion
beam current does not exceed 10…15%, if the bom-
barded target remains unbiased.
Fig. 2. Ion beam current as a function of voltage
applied to the discharge gap: hydrogen (a); helium (b);
argon (c)
Application of the Faraday cup may lead to strong
re-deposition of the material from its edges to the ex-
posed target. This is strongly undesired, because such
deposition would contribute to unnecessary increase of
the target weight, surface composition and other target
properties relevant for the fusion oriented investiga-
tions.
The extraction of the ion beam is characterized by
current efficiency defined as the ratio of the ion beam
current to the discharge current. It shows which part of
b
a
c
ISSN 1562-6016. ВАНТ. 2015. №4(98) 24
the discharge current is converted to the ion beam cur-
rent. This parameter is naturally very important for
space propulsions due to limited availability of the fuel
gas. This parameter is also important for the material
research, because it imposes upper limit on achievable
ion flux for the given pumping system and gas type. In
cases, when expensive gases like tritium are used, this
parameter would define the economic efficiency of the
experimental setup. Fig. 3 shows the current efficiency
for H, He and Ar working gases.
Fig. 3. Current efficiency measured for hydrogen,
helium and argon working gas
One can see that the efficiency for H and Ar species
is generally high and varies between 30 and 40%, while
for He working gas only 10…20% of the discharge cur-
rent is converted into the current of the ion beam.
CONCLUSIONS
The operation of the FALCON ion source has been
investigated with fusion relevant species: hydrogen,
helium and argon. The optimal pressure range has been
maintained, while pumping speed of the system was
1200 l/s. It has been obtained that the beam current for
H and He ions was in the range from 1 to 12 mA, while
the current of the Ar ion beam can be as high as 65 mA.
Generally, the ion beam current increases with the dis-
charge voltage. The current efficiency of the source
operating with H and Ar working gases varies from 30
to 40%, while for He it remains in the range 10…20%.
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Article received 29.04.2015
ISSN 1562-6016. ВАНТ. 2015. №4(98) 25
ГЕНЕРАЦИЯ ПОТОКОВ ИОНОВ ДЛЯ МОДЕЛИРОВАНИЯ ВЗАИМОДЕЙСТВИЯ ПЛАЗМЫ СО
СТЕНКОЙ В ТЕРМОЯДЕРНЫХ УСТАНОВКАХ УСКОРИТЕЛЕМ С АНОДНЫМ СЛОЕМ
А. Гирка, А. Бизюков, Ю. Коляда, К. Середа, И. Бизюков
Исследовалась модификация ускорителя с анодным слоем с использованием фокусировки реверсивным
магнитным полем (ионный источник FALCON) для применения с рабочими газами водородом, гелием и
аргоном. Ток легких ионов не превышал 12 мА, в то время как ток ионного пучка аргона достигал
25…65 мА. Измеренная токовая эффективность находилась в диапазоне 30...40% для водорода и аргона,
10…20% для гелия.
ГЕНЕРАЦІЯ ПОТОКІВ ІОНІВ ДЛЯ МОДЕЛЮВАННЯ ВЗАЄМОДІЇ ПЛАЗМИ
ЗІ СТІНКОЮ В ТЕРМОЯДЕРНИХ УСТАНОВКАХ ПРИСКОРЮВАЧЕМ З АНОДНИМ ШАРОМ
О. Гірка, О. Бізюков, Ю. Коляда, К. Середа, І. Бізюков
Досліджувалася модифікація прискорювача з анодним шаром з використанням фокусування реверсив-
ним магнітним полем (іонне джерело FALCON) для застосування з воднем, гелієм та аргоном в якості робо-
чих газів. Струм легких іонів не перевищував 12 мА, в той час як струм іонного пучка аргону сягав
25…65 мА. Виміряна струмова ефективність була в діапазоні 30...40% для водню та аргону, 10…20% для
гелію.
Introduction
1. Experimental
2. Results and discussion
Conclusions
references
Генерация потоков ионов для моделирования взаимодействия плазмы со стенкой в термоядерных установках ускорителем С анодным слоем
Генерація потоків іонів для моделювання взаємодії плазми зі стінкою в термоядерних установках прискорювачем з анодним шаром
|
| id | nasplib_isofts_kiev_ua-123456789-112241 |
| institution | Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| issn | 1562-6016 |
| language | English |
| last_indexed | 2025-12-07T17:49:44Z |
| publishDate | 2015 |
| publisher | Національний науковий центр «Харківський фізико-технічний інститут» НАН України |
| record_format | dspace |
| spelling | Girka, O. Bizyukov, O. Kolyada, Yu. Sereda, K. Bizyukov, I. 2017-01-18T20:04:27Z 2017-01-18T20:04:27Z 2015 Extraction of fusion relevant ion species from discharge of focused anode layer thruster / O. Girka, O. Bizyukov, Yu. Kolyada, K. Sereda, I. Bizyukov // Вопросы атомной науки и техники. — 2015. — № 4. — С. 22-25. — Бібліогр.: 17 назв. — англ. 1562-6016 PACS: 79.20 Rf https://nasplib.isofts.kiev.ua/handle/123456789/112241 The modification of anode layer thruster, which utilizes the focusing with reversed magnetic field (FALCON ion source), has been investigated for operation with H, He and Ar working gases. Current efficiency was measured to be in the range of 30…40% for H and Ar ion beam, while for He gas it varies from 10 to 20%. Досліджувалася модифікація прискорювача з анодним шаром з використанням фокусування реверсивним магнітним полем (іонне джерело FALCON) для застосування з воднем, гелієм та аргоном в якості робочих газів. Струм легких іонів не перевищував 12 мА, в той час як струм іонного пучка аргону сягав 25…65 мА. Виміряна струмова ефективність була в діапазоні 30...40% для водню та аргону, 10…20% для гелію. Исследовалась модификация ускорителя с анодным слоем с использованием фокусировки реверсивным магнитным полем (ионный источник FALCON) для применения с рабочими газами водородом, гелием и аргоном. Ток легких ионов не превышал 12 мА, в то время как ток ионного пучка аргона достигал 25…65 мА. Измеренная токовая эффективность находилась в диапазоне 30...40% для водорода и аргона, 10…20% для гелия. en Національний науковий центр «Харківський фізико-технічний інститут» НАН України Вопросы атомной науки и техники Нерелятивистская электроника Extraction of fusion relevant ion species from discharge of focused anode layer thruster Генерація потоків іонів для моделювання взаємодії плазми зі стінкою в термоядерних установках прискорювачем з анодним шаром Генерация потоков ионов для моделирования взаимодействия плазмы со стенкой в термоядерных установках ускорителем с анодным слоем Article published earlier |
| spellingShingle | Extraction of fusion relevant ion species from discharge of focused anode layer thruster Girka, O. Bizyukov, O. Kolyada, Yu. Sereda, K. Bizyukov, I. Нерелятивистская электроника |
| title | Extraction of fusion relevant ion species from discharge of focused anode layer thruster |
| title_alt | Генерація потоків іонів для моделювання взаємодії плазми зі стінкою в термоядерних установках прискорювачем з анодним шаром Генерация потоков ионов для моделирования взаимодействия плазмы со стенкой в термоядерных установках ускорителем с анодным слоем |
| title_full | Extraction of fusion relevant ion species from discharge of focused anode layer thruster |
| title_fullStr | Extraction of fusion relevant ion species from discharge of focused anode layer thruster |
| title_full_unstemmed | Extraction of fusion relevant ion species from discharge of focused anode layer thruster |
| title_short | Extraction of fusion relevant ion species from discharge of focused anode layer thruster |
| title_sort | extraction of fusion relevant ion species from discharge of focused anode layer thruster |
| topic | Нерелятивистская электроника |
| topic_facet | Нерелятивистская электроника |
| url | https://nasplib.isofts.kiev.ua/handle/123456789/112241 |
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