Modeling and forming the magnetic field of the heavy ion cyclotron
The heavy ion cyclotron was designed and constructed in the Dzhelepov Laboratory of Nuclear Problem, Joint Institute for Nuclear Research. Ions with A/Z~5 were accelerated up to the energy E=2.4 MeV/nucleon. The ECR source with an intensity of 3.5⋅10¹² ions/sec is used as an ion source. The extr...
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| Cite this: | Modeling and forming the magnetic field of the heavy ion cyclotron / Yu.G. Alenitsky, A.F. Chesnov, S.A. Kostromin, L.M. Onischenko, E.V. Samsonov, N.L. Zaplatin // Вопросы атомной науки и техники. — 2004. — № 2. — С. 78-80. — Бібліогр.: 5 назв. — англ. |
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Alenitsky, Yu.G. Chesnov, A.F. Kostromin, S.A. Onischenko, L.M. Samsonov, E.V. Zaplatin, N.L. 2015-03-31T14:51:12Z 2015-03-31T14:51:12Z 2004 Modeling and forming the magnetic field of the heavy ion cyclotron / Yu.G. Alenitsky, A.F. Chesnov, S.A. Kostromin, L.M. Onischenko, E.V. Samsonov, N.L. Zaplatin // Вопросы атомной науки и техники. — 2004. — № 2. — С. 78-80. — Бібліогр.: 5 назв. — англ. 1562-6016 PACS: 29.20.Hm. https://nasplib.isofts.kiev.ua/handle/123456789/79366 The heavy ion cyclotron was designed and constructed in the Dzhelepov Laboratory of Nuclear Problem, Joint Institute for Nuclear Research. Ions with A/Z~5 were accelerated up to the energy E=2.4 MeV/nucleon. The ECR source with an intensity of 3.5⋅10¹² ions/sec is used as an ion source. The extracted beam of ~10¹¹ ions/sec is intended for the track membrane production. The magnetic field of this cyclotron is formed in the compact magnet with the pole diameter 1.6 m by means of four pairs of sector shims installed symmetrically up and down. The gaps are 100 mm, and 40 mm between the poles and shims, respectively. The proper dependence of the isochronous magnetic field on the radius is created, basically, by increasing the angular extension of sector shims inside the range α = 30º...41.8º. Power consumption of an electromagnet is 25 kW. Циклотрон для прискорення важких іонів спроектований і виготовлений у Лабораторії Ядерних Проблем ім. В.П. Джелепова ОІЯД. Основні параметри магнітної системи циклотрона отримані на підставі розрахунків по аналітичних формулах, за умови рівномірного намагнічування об'єму ферромагнетика, а також по двомірній програмі з використанням сіткової методики (FEMM). Для вибору форми секторних шимм була виготовлена модель магнітної системи в масштабі 1:2,5. Приведено основні параметри магнітної системи і результати моделювання і формування магнітного поля циклотрона. Циклотрон для ускорения тяжелых ионов спроектирован и изготовлен в Лаборатории Ядерных Проблем им. В.П. Джелепова ОИЯИ. Основные параметры магнитной системы циклотрона получены на основании расчетов по аналитическим формулам, при условии равномерного намагничивания объёма ферромагнетика, а также по двухмерной программе с использованием сеточной методики (FEMM). Для выбора формы секторных шимм была изготовлена модель магнитной системы в масштабе 1:2,5. Приведены основные параметры магнитной системы и результаты моделирования и формирования магнитного поля циклотрона. en Національний науковий центр «Харківський фізико-технічний інститут» НАН України Вопросы атомной науки и техники Элементы ускорителей Modeling and forming the magnetic field of the heavy ion cyclotron Моделювання і формування магнітного поля циклотрона важких іонів Моделирование и формирование магнитного поля циклотрона тяжелых ионов Article published earlier |
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Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| collection |
DSpace DC |
| title |
Modeling and forming the magnetic field of the heavy ion cyclotron |
| spellingShingle |
Modeling and forming the magnetic field of the heavy ion cyclotron Alenitsky, Yu.G. Chesnov, A.F. Kostromin, S.A. Onischenko, L.M. Samsonov, E.V. Zaplatin, N.L. Элементы ускорителей |
| title_short |
Modeling and forming the magnetic field of the heavy ion cyclotron |
| title_full |
Modeling and forming the magnetic field of the heavy ion cyclotron |
| title_fullStr |
Modeling and forming the magnetic field of the heavy ion cyclotron |
| title_full_unstemmed |
Modeling and forming the magnetic field of the heavy ion cyclotron |
| title_sort |
modeling and forming the magnetic field of the heavy ion cyclotron |
| author |
Alenitsky, Yu.G. Chesnov, A.F. Kostromin, S.A. Onischenko, L.M. Samsonov, E.V. Zaplatin, N.L. |
| author_facet |
Alenitsky, Yu.G. Chesnov, A.F. Kostromin, S.A. Onischenko, L.M. Samsonov, E.V. Zaplatin, N.L. |
| topic |
Элементы ускорителей |
| topic_facet |
Элементы ускорителей |
| publishDate |
2004 |
| language |
English |
| container_title |
Вопросы атомной науки и техники |
| publisher |
Національний науковий центр «Харківський фізико-технічний інститут» НАН України |
| format |
Article |
| title_alt |
Моделювання і формування магнітного поля циклотрона важких іонів Моделирование и формирование магнитного поля циклотрона тяжелых ионов |
| description |
The heavy ion cyclotron was designed and constructed in the Dzhelepov Laboratory of Nuclear Problem, Joint
Institute for Nuclear Research. Ions with A/Z~5 were accelerated up to the energy E=2.4 MeV/nucleon. The ECR
source with an intensity of 3.5⋅10¹² ions/sec is used as an ion source. The extracted beam of ~10¹¹ ions/sec is intended for the track membrane production. The magnetic field of this cyclotron is formed in the compact magnet with the pole diameter 1.6 m by means of four pairs of sector shims installed symmetrically up and down. The gaps are 100 mm, and 40 mm between the poles and shims, respectively. The proper dependence of the isochronous magnetic field on the radius is created, basically, by increasing the angular extension of sector shims inside the range α = 30º...41.8º. Power consumption of an electromagnet is 25 kW.
Циклотрон для прискорення важких іонів спроектований і виготовлений у Лабораторії Ядерних Проблем
ім. В.П. Джелепова ОІЯД. Основні параметри магнітної системи циклотрона отримані на підставі
розрахунків по аналітичних формулах, за умови рівномірного намагнічування об'єму ферромагнетика, а
також по двомірній програмі з використанням сіткової методики (FEMM). Для вибору форми секторних
шимм була виготовлена модель магнітної системи в масштабі 1:2,5. Приведено основні параметри магнітної
системи і результати моделювання і формування магнітного поля циклотрона.
Циклотрон для ускорения тяжелых ионов спроектирован и изготовлен в Лаборатории Ядерных Проблем
им. В.П. Джелепова ОИЯИ. Основные параметры магнитной системы циклотрона получены на основании
расчетов по аналитическим формулам, при условии равномерного намагничивания объёма ферромагнетика,
а также по двухмерной программе с использованием сеточной методики (FEMM). Для выбора формы секторных шимм была изготовлена модель магнитной системы в масштабе 1:2,5. Приведены основные параметры магнитной системы и результаты моделирования и формирования магнитного поля циклотрона.
|
| issn |
1562-6016 |
| url |
https://nasplib.isofts.kiev.ua/handle/123456789/79366 |
| citation_txt |
Modeling and forming the magnetic field of the heavy ion cyclotron / Yu.G. Alenitsky, A.F. Chesnov, S.A. Kostromin, L.M. Onischenko, E.V. Samsonov, N.L. Zaplatin // Вопросы атомной науки и техники. — 2004. — № 2. — С. 78-80. — Бібліогр.: 5 назв. — англ. |
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2025-11-26T21:08:17Z |
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2025-11-26T21:08:17Z |
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| fulltext |
MODELING AND FORMING THE MAGNETIC FIELD
OF THE HEAVY ION CYCLOTRON
Yu.G.Alenitsky, A.F.Chesnov, S.A.Kostromin, L.M.Onischenko, E.V.Samsonov,
N.L.Zaplatin
Dzhelepov Laboratory of Nuclear Problem, Joint Institute for Nuclear Research, 141980,
Str.Joliot-Curie, 6, Dubna, Russia, fax:+7-09621-66666
E-mail alen@nusun.jinr.ru
The heavy ion cyclotron was designed and constructed in the Dzhelepov Laboratory of Nuclear Problem, Joint
Institute for Nuclear Research. Ions with A/Z~5 were accelerated up to the energy E=2.4 MeV/nucleon. The ECR
source with an intensity of 3.5⋅1012 ions/sec is used as an ion source. The extracted beam of ~1011 ions/sec is intend-
ed for the track membrane production. The magnetic field of this cyclotron is formed in the compact magnet with
the pole diameter 1.6 m by means of four pairs of sector shims installed symmetrically up and down. The gaps are
100 mm, and 40 mm between the poles and shims, respectively. The proper dependence of the isochronous magnet-
ic field on the radius is created, basically, by increasing the angular extension of sector shims inside the range α =
30º...41.8º. Power consumption of an electromagnet is 25 kW.
PACS: 29.20.Hm.
1. INTRODUCTION
The heavy ion fixed energy cyclotron based on the
compact magnet with the pole diameter 1.6 m was de-
signed and constructed in JINR. The ions with A/Z=5
were accelerated up to the energy E=2.4 MeV/nucleon
for track membrane production. The isochronous mag-
net field is formed by means of the fore pair of sector
shims. The beam phase shift in the formed field is less
then ± 10º of RF, and the first magnetic field harmonic
is less then 3 G in all the radii of the beam acceleration.
Power consumption of the magnet is 25 kW. The analyt-
ical formulas assuming a uniform magnetization of the
magnet elements were used for the preliminary choice
of the magnet structure. The 2D computer simulation
based on a mesh technique (FEMM) was used to check
this choice. To find the final form of the sector shims
the magnetic model with scale 1:2.5 was constructed.
The 3D computer simulation based on RADIA code was
made to determine an influence of some parts of the
magnet on the field structure. The choice of main pa-
rameters of the magnet and the modeling and forming
the isochronous field are described below.
2. CHOICE OF THE BASIC PARAMETERS
OF THE MAGNETIC SYSTEM
Analytical formulas assuming a uniform magnetiza-
tion of the magnet elements were used for the prelimi-
nary choice of the magnet structure [1]. A 2D computer
simulation based on a mesh technique was used [2] to
check this choice. To find the final form of the sector
shims the magnetic model on a scale 1:2.5 was con-
structed [3]. The 3D computer simulation based on the
RADIA code [4] was carried out to determine an influ-
ence of some parts of the magnet on the field structure.
The H-shape electromagnet is used for cyclotron.
Four pairs of sector shims are placed on the poles to
provide axial focusing. At the same time, an increase in
their angular size with the radius from α=30˚ in center
to α=41.8˚ at the last radii is used to form the
isochronous magnetic field. Poles and yokes of the mag-
net have axial holes for the axial injection. The main pa-
rameters of magnetic system are given in the Table and
the view of computing model is shown in Fig.1.
The basic parameters of the cyclotron magnetic system
Overall dimensions of yoke (mm3) 3700х2000
х1650
Diameter of poles (mm) 1600
Gap between poles (mm) 100
Weight of iron (t) 83
Height of sectors (mm) 30
Gap between coils (mm) 200
Section of the coil (mm) 260 х 200
Section of the coil on copper (mm) 220 х 160
Ampere – turns of the coil (kA) ~95
Cross section of the conductor (mm) 18.5х18.5
Coil current (A) 524
Voltage on the coil (V) 50
Power consumption (kW) 25
Weight of copper (t) 2.4
Fig.1. Main view of 3D computing model
The sector shims whose form was chosen for model-
ing (Figs.2,3) were fabricated (Fig.4) at the factory with
a high accuracy. The valley shims applied to exact cre-
ation of the isochronous field and for correction of the
first harmonic of the cyclotron magnetic field are also
shown in Figs.2,3.
In the coil case of the cyclotron magnet’s internal
cylinder and ring inverted to the horizontal yoke are
made of steel to provide a growing average field in the
gap of the magnet. A quarter of the magnet pole with
___________________________________________________________
PROBLEMS OF ATOMIC SIENCE AND TECHNOLOGY. 2004. № 2.
Series: Nuclear Physics Investigations (43), p.78-80. 78
mailto:alen@nusun.jinr.ru
sector and valley shims and steel elements of the coil
case are shown in Fig.2.
0
250
500
750
1000
X
500
0
500
Y
100200300Z
0
250
500
750
1000
X
100200300Z
Fig.2. 3D computing model of ¼ pole, one sector and
valley shims and the ferromagnetic parts of the coil
case
Fig.3. Pole with sector and valley shims up cross sec-
tion; down-plane view
Fig.4. In foreground-bottom pole with the vacuum
chamber, on the left-top pole with the cover of the vacu-
um chamber
An influence of steel elements of coil cases comput-
ed by the 3D code Radia on a magnetic field is shown in
Fig.5. The curve dB represents a difference between the
calculated average magnetic field with steel elements
and without them. It is seen, that these constructive ele-
ments of the coil case create a magnetic field smoothly
growing on a radius up to 300 G. The difference be-
tween the calculated dB and experimental field was
found less than 10 G.
0 100 200 300 400 500 600 700 800
0,00
0,01
0,02
0,03
dB
(T
)
R(cm)
Fig.5. Magnetic field of the coils case steel elements
computed by the 3D code Radia
To measure the magnetic field we have designed and
constructed a measuring system comprising:
1. Mechanical system that provides both azimuthal
(by step motor) and radial (manually) moving of
the Hall probe.
2. PC with the codes for control of the measuring
system and for preliminary computing of the
measurement results.
The axial betatron frequency Qz is equal (0.05...0.4)
inside the radial range (0,05...0,75) m, while the radial
betatron frequency Qr changes from 1.0 to 1.01. Close-
ness Qr to unity requires to form the average magnetic
field with a high accuracy and establishes the upper lim-
it 3G for the first harmonic of imperfections.
During the magnet production all measures were
taken to fabricate the gap between poles (h=100 mm)
and the gaps between all four pairs of sector shims
(h=40мм) with an accuracy Δh<0.05 mm To guarantee
this requirement all planes of the yoke parts and poles
that come into contact with each other were polished. In
spite of these efforts the gaps between sectors were found
(after installing the magnet on the place) exceeding the
nominal size of 40 mm by 0.06...0.13 mm. Then stainless
steel inserts of proper size 40.1±0.01 mm were fabricated
and installed between each pair of sectors at radii 780–
800 mm where they do not cross the beam path.
3. FORMING OF CYCLOTRON
MAGNETIC FIELD
The proper dependence of the average magnetic
field on radius is created, basically, by increasing the
angular extent of the sector shims. In addition the valley
shims are placed for exact shimming of the average
field and for correction of the first harmonic. The exter-
nal borders of the valley shims are shown in Fig.3. This
is unique place for the valley shims arrangement, be-
cause two opposite valleys are used for the dees.
The result of measuring the magnetic field without
valley shims is shown in Fig.6 (curve 1). It is evident
that the magnetic field in the range of R=660...740 mm
is higher then needed one even without the valley shims.
Hence the only possible decision was to extract some
part of steel from the sector shims. To find experimen-
tally the proper quantity of steel which has to be extract-
ed, some of steel bolts which fix the sector shims to the
pole at a radius of 710 mm were changed by stainless
steel ones. Using the results of these experiments it was
___________________________________________________________
PROBLEMS OF ATOMIC SIENCE AND TECHNOLOGY. 2004. № 2.
Series: Nuclear Physics Investigations (43), p.78-80.79
decided to make in each sector shim two 21 mm holes
placed at the radius 740 mm at the angle 17˚ symmetri-
cally to the sector shims axe (Fig.3).
0 10 20 30 40 50 60 70 80
14,7
14,8
14,9
15,0
15,1
14,7
14,8
14,9
15,0
15,1
Bis2 1Bm
(k
G)
R (cm)
Fig.6. Average magnetic field: Bis-(required); 1-first
measurement;2-measurement with valley shims
0 20 40 60 80
14,5
14,6
14,7
14,8
14,9
15,0
dFi
B19
dF
i (d
eg
)
B is
B 21
B (
kG
)
R (cm)
-50
0
50
100
150
200
Fig.7. Average magnetic field: Bis-designed;
B19-without valley shims; B21-final after shimming;
dFi-calculated beam phase shift
The obtained average field with such holes is shown
in Fig.7 (curve В19). This field is lower than needed
one and therefore the valley shims were used to form
the needed field. The final average magnetic field
0,004
0,002
0,000
0,002
0,004
0
30
60
90
120
150
180
210
240
270
300
330
IV
III
II
I
B
1
(k
G
)
exp 24
ось магнита, проходящая
через стойки
цифрами указаны радиусы
измерений в см
40
60
68
64
70
75
77
fi mes
0
2
4
6
8
10
Fig.8. Amplitude and phase of the first harmonic of a
magnetic field
formed with the valley shims is shown in Fig.7 (curve
B21). The corresponding beam phase shift does not ex-
ceed ~±10° RF (Fig.7, curve dFi).
The first harmonic B1 of the magnetic field was
found less then 5 G just after installation of the magnet.
This good result is explained by a high accuracy of
fabrication and assembling the magnet. Rather small
changes of valley shims have allowed to decrease
B1<3G. The amplitude and the phase of the first har-
monic for the different radii are shown in Fig.8. For
radii R<40 cm B1 is less than 2 G.
4. CONCLUSIONS
The analytical formulas, the 2D computer simulation
and the modeling of the magnet element were used for
the preliminary choice of the magnet structure. For ex-
act approach to the isochronous field the valley shims
were used. The small value of the first harmonic is the
result of a high accuracy of fabrication of the ferromag-
netic elements.
In August 2002 the beam of ions 40Ar8+ was acceler-
ated up to final radius, beam losses during acceleration
were not significant [5].
REFERENCES
1. V.I. Danilov. Forming the magnetic field for the ac-
celerators with space variation, Dissertation, Dub-
na, 1959, (in Russian)
2. httm://femm.berlios.de/index.html
3. Yu.G.Alenitsky et al Modeling of the magnetic sys-
tem of isochronous cyclotron CYTRECK // Com-
munications of JINR, Р9-2002-185, Dubna, 2002,
(in Russian)
4. www.Srf.fr.machine.groups.insertion.devices.Codes
/Radia/RadiaTitle.html
5. http://trackpore.com/
МОДЕЛИРОВАНИЕ И ФОРМИРОВАНИЕ МАГНИТНОГО ПОЛЯ ЦИКЛОТРОНА
ТЯЖЕЛЫХ ИОНОВ
Ю.Г. Аленицкий, Н.Л. Заплатин, С.А. Костромин, Л.М. Онищенко, Е.В. Самсонов, А.Ф. Чеснов
Циклотрон для ускорения тяжелых ионов спроектирован и изготовлен в Лаборатории Ядерных Проблем
им. В.П. Джелепова ОИЯИ. Основные параметры магнитной системы циклотрона получены на основании
расчетов по аналитическим формулам, при условии равномерного намагничивания объёма ферромагнетика,
а также по двухмерной программе с использованием сеточной методики (FEMM). Для выбора формы сек-
торных шимм была изготовлена модель магнитной системы в масштабе 1:2,5. Приведены основные пара-
метры магнитной системы и результаты моделирования и формирования магнитного поля циклотрона.
МОДЕЛЮВАННЯ І ФОРМУВАННЯ МАГНІТНОГО ПОЛЯ ЦИКЛОТРОНА ВАЖКИХ ІОНІВ
Ю.Г. Аленицький, Н.Л. Заплатин, С.А. Костромин, Л.М. Онищенко, Є.В. Самсонов, А.Ф. Чеснов
80
Циклотрон для прискорення важких іонів спроектований і виготовлений у Лабораторії Ядерних Проблем
ім. В.П. Джелепова ОІЯД. Основні параметри магнітної системи циклотрона отримані на підставі
розрахунків по аналітичних формулах, за умови рівномірного намагнічування об'єму ферромагнетика, а
також по двомірній програмі з використанням сіткової методики (FEMM). Для вибору форми секторних
шимм була виготовлена модель магнітної системи в масштабі 1:2,5. Приведено основні параметри магнітної
системи і результати моделювання і формування магнітного поля циклотрона.
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PROBLEMS OF ATOMIC SIENCE AND TECHNOLOGY. 2004. № 2.
Series: Nuclear Physics Investigations (43), p.78-80.81
4. ConclusionS
References
МОДЕЛИРОВАНИЕ И ФОРМИРОВАНИЕ МАГНИТНОГО ПОЛЯ ЦИКЛОТРОНА
ТЯЖЕЛЫХ ИОНОВ
МОДЕЛЮВАННЯ І ФОРМУВАННЯ МАГНІТНОГО ПОЛЯ ЦИКЛОТРОНА ВАЖКИХ ІОНІВ
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