Dynamics of heavy ions in the isochronous cyclotron for production of nuclear membranes
Isochronous cyclotron CYTRECK intended for a production of nuclear membranes was put into operation in 2002 year in Dubna. The ions with the relation A/Z=5 are accelerated to the energy ∼2.4 MeV/nucleon and extracted at the intensity ∼2⋅10¹¹ ions per second. The calculations of the ions dynamics...
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irk-123456789-793762015-04-01T03:02:38Z Dynamics of heavy ions in the isochronous cyclotron for production of nuclear membranes Onischenko, L.M. Samsonov, E.V. Динамика пучков Isochronous cyclotron CYTRECK intended for a production of nuclear membranes was put into operation in 2002 year in Dubna. The ions with the relation A/Z=5 are accelerated to the energy ∼2.4 MeV/nucleon and extracted at the intensity ∼2⋅10¹¹ ions per second. The calculations of the ions dynamics beginning from the exit of an inflector to their extraction from the cyclotron chamber are examined in the report. Ізохронний циклотрон ЦИТРЕК, призначений для виробництва ядерних мембран працює в Дубні з 2002 р. Іони з відношенням A/Z=5 прискорюються до енергії ∼2.4 МеВ/нукл при інтенсивності ∼2⋅10¹¹ іонів у секунду. У статті приводиться розрахунок динаміки іонів, починаючи від виходу з інфлектора до їхнього виходу з камери прискорювача. Изохронный циклотрон ЦИТРЕК, предназначенный для производства ядерных мембран работает в Дубне с 2002 г. Ионы с отношением A/Z=5 ускоряются до энергии ∼2.4 МэВ/нуклон при интенсивности ∼2⋅10¹¹ ионов в секунду. В статье приводится расчет динамики ионов, начиная от выхода из инфлектора до их вывода из камеры ускорителя. 2004 Article Dynamics of heavy ions in the isochronous cyclotron for production of nuclear membranes / L.M. Onischenko, E.V. Samsonov // Вопросы атомной науки и техники. — 2004. — № 2. — С. 129-131. — Бібліогр.: 2 назв. — англ. 1562-6016 PACS: 29.20.Hm, 29.27.Bd, 83.10.Rs http://dspace.nbuv.gov.ua/handle/123456789/79376 en Вопросы атомной науки и техники Національний науковий центр «Харківський фізико-технічний інститут» НАН України |
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Динамика пучков Динамика пучков Onischenko, L.M. Samsonov, E.V. Dynamics of heavy ions in the isochronous cyclotron for production of nuclear membranes Вопросы атомной науки и техники |
| description |
Isochronous cyclotron CYTRECK intended for a production of nuclear membranes was put into operation in
2002 year in Dubna. The ions with the relation A/Z=5 are accelerated to the energy ∼2.4 MeV/nucleon and extracted
at the intensity ∼2⋅10¹¹ ions per second. The calculations of the ions dynamics beginning from the exit of an inflector
to their extraction from the cyclotron chamber are examined in the report. |
| format |
Article |
| author |
Onischenko, L.M. Samsonov, E.V. |
| author_facet |
Onischenko, L.M. Samsonov, E.V. |
| author_sort |
Onischenko, L.M. |
| title |
Dynamics of heavy ions in the isochronous cyclotron for production of nuclear membranes |
| title_short |
Dynamics of heavy ions in the isochronous cyclotron for production of nuclear membranes |
| title_full |
Dynamics of heavy ions in the isochronous cyclotron for production of nuclear membranes |
| title_fullStr |
Dynamics of heavy ions in the isochronous cyclotron for production of nuclear membranes |
| title_full_unstemmed |
Dynamics of heavy ions in the isochronous cyclotron for production of nuclear membranes |
| title_sort |
dynamics of heavy ions in the isochronous cyclotron for production of nuclear membranes |
| publisher |
Національний науковий центр «Харківський фізико-технічний інститут» НАН України |
| publishDate |
2004 |
| topic_facet |
Динамика пучков |
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http://dspace.nbuv.gov.ua/handle/123456789/79376 |
| citation_txt |
Dynamics of heavy ions in the isochronous cyclotron for production of nuclear membranes / L.M. Onischenko, E.V. Samsonov // Вопросы атомной науки и техники. — 2004. — № 2. — С. 129-131. — Бібліогр.: 2 назв. — англ. |
| series |
Вопросы атомной науки и техники |
| work_keys_str_mv |
AT onischenkolm dynamicsofheavyionsintheisochronouscyclotronforproductionofnuclearmembranes AT samsonovev dynamicsofheavyionsintheisochronouscyclotronforproductionofnuclearmembranes |
| first_indexed |
2025-07-06T03:26:44Z |
| last_indexed |
2025-07-06T03:26:44Z |
| _version_ |
1836866501435457536 |
| fulltext |
BEAM DYNAMICS
DYNAMICS OF HEAVY IONS IN THE ISOCHRONOUS CYCLOTRON
FOR PRODUCTION OF NUCLEAR MEMBRANES
L.M. Onischenko, E.V. Samsonov
Joint Institute for Nuclear Research 141980, str.Joliot-Curie, 6, Dubna, Russia
E-mail: sams@nusun.jinr.ru
Isochronous cyclotron CYTRECK intended for a production of nuclear membranes was put into operation in
2002 year in Dubna. The ions with the relation A/Z=5 are accelerated to the energy ∼2.4 MeV/nucleon and extracted
at the intensity ∼2⋅1011 ions per second. The calculations of the ions dynamics beginning from the exit of an inflector
to their extraction from the cyclotron chamber are examined in the report.
PACS: 29.20.Hm, 29.27.Bd, 83.10.Rs
1. MAIN PARAMETERS OF THE
CYCLOTRON
CYTRECK is 4-sector compact isochronous cyclo-
tron equipped by 14GHz ECR ion source as an injector.
Cyclotron has axial injection line, spiral inflector, two
accelerating dees and electrostatic extraction system.
Some cyclotron parameters are shown in Table and its
layout in Fig.1.
Main parameters of the CYTRECK
Type of accelerated ion A/Z
Injection energy (keV/nucl)
Extraction energy (MeV/nucl)
Average magnetic field (T)
Betatron frequencies: νr ; νz
Radius of injection (cm)
Radius of extraction (cm)
Emittances on injection (π mm⋅mrad)
Emittances on extraction (π mm⋅mrad)
Phase width of the bunch (°RF)
Orbital frequency (MHz)
Harmonic number
Number of dees
Angular width of dees (°)
Accelerating voltage (kV)
5
3.0
2.4
1.48
1.015; 0.3
∼3.0
73.0
∼150
∼15
∼20
4.626
4
2
40
50
Fig.1. Layout of the cyclotron vacuum chamber
with 4 sectors and 2 dees. ESD1, ESD2 – electrostatic
extraction system, FD – ferromagnetic focusing
channel, SM – steering magnet
2. CENTRAL REGION
Configuration of the central region electrodes has
the determining effect on the transverse oscillations of
ions. During the analysis of particle dynamics in the
central region of CYTRECK a three-dimensional elec-
tric field, obtained as a result of numerical simulation
was used. In order to get the optimum configuration of
center the axial and radial size of the diaphragms (see
Fig.2), dimensions of window in the inflector case, and
also a width of first and second accelerating gaps were
varied. The aim of optimization was obtaining the smal-
lest possible amplitudes of radial oscillations after the
first five revolutions of beam on acceptable level of the
axial losses. Axial losses arise due to axial divergence of
the beam just after the inflector exit. Code CENMOT [1]
was used for a particle tracking inside this region.
Fig.2. Layout of the cyclotron central region
After ten changes of the central region geometry the
required configuration was chosen. In Fig.3 one can see
axial trajectories during 1-st turn. Ion losses on dees and
diaphragms are not larger than 40% of injected beam
with 20°RF length. Computations show that the maxi-
mal amplitude of free radial oscillations after 5 turns is
not greater than 5 mm.
___________________________________________________________
PROBLEMS OF ATOMIC SIENCE AND TECHNOLOGY. 2004. № 2.
Series: Nuclear Physics Investigations (43), p.129-131. 129
Fig.3. Axial trajectories of 100 ions for 1-st turn. The
ion losses on the dees and diaphragms are neglected
3. MAIN ACCELERATION REGION
For calculating of beam dynamics in the basic accel-
eration region were undertaken 587 ions, having the
amplitude of axial oscillations not more than 8 mm in
the center of cyclotron. Calculation was carried out dur-
ing 60-70 revolutions, until all ions reached the entrance
of the extraction system. In the calculations the analytic-
al description [2] of electric field of dees was used.
Magnetic field parameters are given in figs. 4,5.
Fig.4. Average value Bav and amplitudes of multiple
harmonics B4 – B16 of the cyclotron magnetic field
Fig. 5. Amplitude b1 and phase f1 of the 1-st harmonic
of azimuthal imperfection
Fig.6 shows the amplitudes of the free radial oscilla-
tions of ions in the dependence on the mean radius of
accelerated orbit. It is evident that the amplitude spread
increases from 4 to 9 mm (reason – action of the 1-st
harmonic of magnetic field). However, for 98% of ions
toward the end of the acceleration the amplitude of radi-
al oscillations do not exceed 6 mm, that, as it will be
shown below, gives good beam parameters at the en-
trance of the extraction system.
Fig. 6. Amplitudes of free radial oscillations versus ra-
dius
The results of simulation of the differential probe
signal are shown in Fig.7. This probe is located on azi-
muth 90° and has lamella width of 1 mm. One sees that
the first 9 turns are completely separated, and up 50
turns can be identified in the signal amplitudes.
Fig. 7. Signal of differential probe versus radius
Frequencies of betatron oscillations are shown in
Fig.8. Inside main acceleration region their values com-
prise Qr≈1.015, Qz≈0.33. Only at extraction radius
73.0 cm radial frequency crosses resonance value Qr=1
and axial one approaches to Qz=0.5. But due to large ra-
dial gain (∼0.7 cm), deterioration of the beam paramet-
ers do not occur in this region.
Fig. 8. Frequencies of free oscillations versus radius
Fig.9 represents phase motion of ions in the main ac-
celeration region. These results show that average mag-
netic field is formed with high accuracy without using
of correction coils.
Fig.9. Phase motion of ions versus radius beginning
from 2-nd turn
4. EXTRACTION SYSTEM
Fig.10 depicts in the coordinates (azimuth - radius)
the position of the extraction system relative to the
boundary of the circulating beam, shims and magnet
pole. Here is shown position of probes, intended for
measuring the throw of beam to the entrance of the sys-
tem and its parameters after both electrostatic elements.
130
280 290 300 310 320 330 340 350 360 370
70
75
80
85
90
95
100
Central
trajectory
Probes
beam
of
circulating
Boundary
FD
ESD2
ESD1
Shim
Pole
Shim
R
ad
iu
s
(c
m
)
Azimuth ( o )
Fig.10. Sketch view of extraction system
Extraction system consists of three elements: elec-
trostatic deflectors ESD1 and ESD2, and passive ferro-
magnetic device FD. Deflectors represent itself the seg-
ments of the cylindrical capacitors, whose internal plate
(septum) is under zero potential, and external under the
negative potential by value approximately 50 kV. Ferro-
magnetic device consists of three steel plates magnet-
ized by the magnetic field of cyclotron. The throw of
beam to the entrance of the system is ensured due to ra-
dial gain ∼7 mm provided by acceleration.
ESD1 provides primary radial deviation of the ex-
tracted beam on ∼12 mm from the boundary of circulat-
ing one. Inside this element there is no need of creating
the focusing gradient of electric field, since beam does
not achieve here a dropped fringing field.
ESD2 makes additional deviation of beam outside,
(on the exit of this element the beam is located already
at a distance of about 70 mm from circulating one), and
also provides the compensation for the action of the ra-
dially defocusing gradient of fringe magnetic field.
Basic purpose of FD is the radial beam focusing and
additional its deviation outside the vacuum chamber.
Fig.11.Beam parameters on phase planes (R, Pr) and
(Z, Pz) at the entrance of extraction system
Fig.12.Beam parameters on phase planes (X, Px) and
(Z, Pz) at the entrance of steering magnet SM
Figs.11,12 show phase beam portraits at entrance of
ESD1 and steering magnet SM, accordingly. Final beam
average energy W=2.4 MeV/A, energy spread ∆W/W=±
1%, transverse emittances εr≈εz≈15 πmm⋅mrad. Ion
losses inside the extraction system when it occupies op-
timal position do not exceed 15% of the circulating
beam. High extraction efficiency imposes the following
requirements to the magnetic and accelerating systems.
First harmonic of the magnetic field imperfections must
be less than 3 G, the amplitude and phase misalignment
of dees should be in limits ±0.5 kV and ±5° RF, respect-
ively.
ACKNOWLEDGEMENTS
The authors would like to express their gratitude to
N.G.Shakun for the computation of electric field in the
central region of the cyclotron.
REFERENCES
1. E.V.Samsonov // Proceedings of Workshop on the
magnetic field and ion beam dynamics of the
VINCY cyclotron, Dubna. 1996, p.156.
2. N.Hazewindus et al. // Nuclear Instruments and
Methods. 1974, v.118, p.125.
ДИНАМИКА ТЯЖЕЛЫХ ИОНОВ В ИЗОХРОННОМ ЦИКЛОТРОНЕ
ДЛЯ ПРОИЗВОДСТВА ЯДЕРНЫХ МЕМБРАН
Л.М. Онищенко, Е.В. Самсонов
Изохронный циклотрон ЦИТРЕК, предназначенный для производства ядерных мембран работает в Дуб-
не с 2002 г. Ионы с отношением A/Z=5 ускоряются до энергии ∼2.4 МэВ/нуклон при интенсивности ∼2⋅
1011 ионов в секунду. В статье приводится расчет динамики ионов, начиная от выхода из инфлектора до их
вывода из камеры ускорителя.
ДИНАМІКА ВАЖКИХ ІОНІВ В ІЗОХРОННОМУ ЦИКЛОТРОНІ
ДЛЯ ВИРОБНИЦТВА ЯДЕРНИХ МЕМБРАН
Л.М. Онищенко, Є.В. Самсонов
Ізохронний циклотрон ЦИТРЕК, призначений для виробництва ядерних мембран працює в Дубні з
2002 р. Іони з відношенням A/Z=5 прискорюються до енергії ∼2.4 МеВ/нукл при інтенсивності ∼2⋅1011 іонів
у секунду. У статті приводиться розрахунок динаміки іонів, починаючи від виходу з інфлектора до їхнього
виходу з камери прискорювача.
___________________________________________________________
PROBLEMS OF ATOMIC SIENCE AND TECHNOLOGY. 2004. № 2.
Series: Nuclear Physics Investigations (43), p.129-131. 131
132
Joint Institute for Nuclear Research 141980, str.Joliot-Curie, 6, Dubna, Russia
Main parameters of the CYTRECK
3. MAIN ACCELERATION REGION
4. EXTRACTION SYSTEM
ACKNOWLEDGEMENTS
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