Accelerating structure with alternating-phase and permanent magnet focusing
Proposed is the method for particle motion stability in linacs based on a combination of phase-alternating and longitudinal magnetic focusing using permanent magnets made of neodymium-iron-boron alloy. Presented are the results of the accelerating structure calculations. Предложен метод обеспечения...
Збережено в:
| Опубліковано в: : | Вопросы атомной науки и техники |
|---|---|
| Дата: | 2014 |
| Автори: | , , , , |
| Формат: | Стаття |
| Мова: | Англійська |
| Опубліковано: |
Національний науковий центр «Харківський фізико-технічний інститут» НАН України
2014
|
| Теми: | |
| Онлайн доступ: | https://nasplib.isofts.kiev.ua/handle/123456789/79986 |
| Теги: |
Додати тег
Немає тегів, Будьте першим, хто поставить тег для цього запису!
|
| Назва журналу: | Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| Цитувати: | Accelerating structure with alternating-phase and permanent magnet focusing / Ye.V. Gussev, P.A. Demchenko, N.G. Shulika, O.N. Shulika, D.Yu. Zalesky // Вопросы атомной науки и техники. — 2014. — № 3. — С. 24-26. — Бібліогр.: 2 назв. — англ. |
Репозитарії
Digital Library of Periodicals of National Academy of Sciences of Ukraine| _version_ | 1859837620895350784 |
|---|---|
| author | Gussev, Ye.V. Demchenko, P.A. Shulika, N.G. Shulika, O.N. Zalesky, D.Yu. |
| author_facet | Gussev, Ye.V. Demchenko, P.A. Shulika, N.G. Shulika, O.N. Zalesky, D.Yu. |
| citation_txt | Accelerating structure with alternating-phase and permanent magnet focusing / Ye.V. Gussev, P.A. Demchenko, N.G. Shulika, O.N. Shulika, D.Yu. Zalesky // Вопросы атомной науки и техники. — 2014. — № 3. — С. 24-26. — Бібліогр.: 2 назв. — англ. |
| collection | DSpace DC |
| container_title | Вопросы атомной науки и техники |
| description | Proposed is the method for particle motion stability in linacs based on a combination of phase-alternating and longitudinal magnetic focusing using permanent magnets made of neodymium-iron-boron alloy. Presented are the results of the accelerating structure calculations.
Предложен метод обеспечения устойчивости движения частиц в линейных ускорителях на основе ком-бинации переменно-фазовой фокусировки и продольного магнитного поля на постоянных магнитах на базе сплава неодим-железо-бор. Приведены результаты разработки ускоряющей структуры.
Запропоновано метод забезпечення стійкості руху часток у лінійних прискорювачах на основі комбінації змінно-фазового фокусування та повздовжнього магнітного поля на постійних магнітах на базі сплаву не-одим-залізо-бор. Наведено результати розробки прискорюючої структури.
|
| first_indexed | 2025-12-07T15:35:57Z |
| format | Article |
| fulltext |
ISSN 1562-6016. ВАНТ. 2014. №3(91) 24
ACCELERATING STRUCTURE WITH ALTERNATING-PHASE
AND PERMANENT MAGNET FOCUSING
Ye.V. Gussev, P.A. Demchenko, N.G. Shulika, O.N. Shulika, D.Yu. Zalesky
National Science Center “Kharkov Institute of Physics and Technology”, Kharkov, Ukraine
Proposed is the method for particle motion stability in linacs based on a combination of phase-alternating and
longitudinal magnetic focusing using permanent magnets made of neodymium-iron-boron alloy. Presented are the
results of the accelerating structure calculations.
PACS: 29.20.Ej
INTRODUCTION
The means to enhance stability of proton beam fo-
cusing in a linear resonance accelerator with alternating-
phase focusing are under study at the Institute of Plasma
Electronics and New Acceleration Methods of NSC
KIPT. It is well known that there exists a very strong
connection between longitudinal and transverse particle
dynamics in linac accelerating channels with alternat-
ing-phase focusing. As a result, effective beam emmit-
tance increases leading to current loses and activation of
linac structural units [1].
To increase the effect of proton beam focusing by
RF electric field and, therefore, to decrease an ampli-
tude of particle radial oscillations in an accelerating
channel, it is proposed to apply an external magnetic
field in gaps between drift tubes [1].
There are several ways to produce a longitudinal
magnetic field in accelerating gaps between axial-
symmetric drift tubes. One of them is to introduce inser-
tions made of ferromagnetic material with high satura-
tion induction into drift tubes (Fig. 1). A sequence of the
drift tubes with ferromagnetic core forms a magnetic
circuit where magnetic field is concentrated in acceler-
ating gaps between the tubes. To lessen dissipation of
magnetic induction flux along the drift tubes, it is im-
portant to ensure the ferromagnetic material is not in the
saturation mode and possesses high relative magnetic
permeability µr.
4 3
2
6
5
1
Fig. 1. Section with a combination of phase-alternative
and magnetic focusing: 1 – resonator; 2 – drift tubes;
3 – magnetic conductor; 4 – solenoid; 5 – resonator
bottom; 6 – magnetic induction flux line
Thus, the drift tubes have two functions: on the one
hand they serve as electrodes with voltage difference to
accelerate charged particles, and on the other hand they
serve as magnetic poles for additional particle beam
magnetic focusing. Fig. 1 illustrates a conceptual ver-
sion of a section with combined alternating-phase and
magnetic focusing [1].
The magnetic circuit is formed by the drift tube se-
quence and the yoke system with a coil to provide mag-
netic flux Φ, see Fig. 1. The coil is outside the vacuum
chamber with the accelerating structure.
The above design of an accelerating channel with
combined focusing was named a structure with spatially
combined alternating-phase and magnetic focusing.
Such structures can be used to accelerate proton beams
in low and medium energy range (up to 100 MeV).
0 200 400 600 800 1000 1200 1400 1600
0,00
0,05
0,10
0,15
0,20
0,25
0,30
0,35
B,
T
L, mm
Fig. 2. Magnetic induction flux distribution along
the accelerating section axis
However, the mentioned magnetic field generation
procedure is effective only for a short accelerating struc-
ture due to strong magnetic field damping at the struc-
ture middle (Fig. 2).
A substantial advance has been recently achieved in
the development of permanent magnets made of neo-
dymium-iron-boron (NIB) alloy. This article presents
some results of studies of an accelerating structure that
implements a combination of phase-alternating and
based on permanent NIB magnets magnetic focusing.
Such magnets could be placed inside drift tubes of the
structure. Thus the magnetic flux damping along the
accelerating section does not develop.
DEVELOPMENT AND STUDIES
OF THE ACCELERATING STRUCTURE
WITH CONBIMED PHASE-ALTERNATING
AND MAGNETIC FOCUSING BASED
ON PERMANENT MAGNETS
Fig. 3 presents a general view of the acceleration
structure that provides acceleration from 2.08 up to
3.86 MeV. A CH-structure serves as a resonator. To
ensure mechanical stability of the structure, each drift
tube has two holders diametrically opposed (cruciform-
like mount).
ISSN 1562-6016. ВАНТ. 2014. №3(91) 25
Fig. 3. General view of the accelerating structure
The structure contains 19 accelerating gaps (20 drift
tubes). The outer diameter of the structure is 40.0 cm,
operating frequency 201.25 MHz, excitation power
915 kW, Q-factor comes to 13000. The drift tubes
measure 1.5 and 4.0 cm in inner and outer diameter,
respectively. A NIB magnetic insertion is placed inside
each drift tube with opposite orientation of magnetic
poles in the adjacent tubes.
0 20 40 60 80 100 120 140 160
0,0
0,2
0,4
0,6
0,8
1,0|Ez|,
a.u.
L, cm
Fig. 4. Electric field distribution along the structure axis
Average amplitude of rf electric field in the gap cen-
ter runs as high as 108.8 kV/cm (Fig. 4) making mag-
netic lens focusing ineffective for particle motion stabil-
ity. Thus, to ensure reasonable stability of particle mo-
tion it is better to take advantage of phase-alternating
focusing. Hence a combination of magnetic and phase-
alternating focusing assures particle motion stability in
the structure.
0 50 100 150 200 250 300
-2,0
-1,5
-1,0
-0,5
0,0
0,5
1,0
1,5
2,0
B
, T
L, mm
a b
Fig. 5. a – magnetic field lines by longitudinally
oriented magnets; b – magnetic induction distribution
along the structure axis
0 50 100 150 200 250 300
-2,0
-1,5
-1,0
-0,5
0,0
0,5
1,0
1,5
2,0
B,
T
L, mm
a b
Fig. 6. a – magnetic field lines by radially oriented
magnets; b – magnetic induction distribution along
the structure axis
Basically, a magnet can be magnetized in two major
directions, namely, through its thickness (here we call it
transverse or radial orientation) or its length (a longitu-
dinally oriented magnet).
Fig. 5,a and Fig. 6,a depict magnetic line distribution
in radially and longitudinally oriented system of four
magnetic units respectively. Axial distribution of mag-
netic induction is presented in Fig. 5,b and Fig. 6,b. It is
worth to mention that magnetic insertions in radially
and longitudinally oriented systems are of equal vol-
ume. As is obvious from the plots, magnetic induction
in the system with radially oriented magnetic insertions
exceeds magnetic induction in the system with longitu-
dinally oriented magnets by factor of 1.5.
Besides, it is worthy of note that the behavior of in-
duction distribution along the axis in the case of radial
magnetic orientation differs from the case of longitudi-
nal one. In the former case induction distribution reach-
es its maximal magnitude in the middle of each gap
while in the latter case the maximum is observed in the
center of each drift tube. And since the magnetic field is
almost zero in the gaps, gap electric strength increases
[2].
It is believed that radially oriented magnetic inser-
tions provide stronger focusing than longitudinally ori-
ented magnets. This suggestion is supported by the re-
sults of numerical simulation of particle dynamics.
Fig. 7 shows the dependence of output current on input
one for three options, namely, longitudinally and radial-
ly oriented magnet insertions, and without external
magnetic field.
0 10 20 30 40 50 60 70 80 90
5
10
15
20
25
30
35
40
45
50
55
60
I ou
tp
ut
, m
A
Iinput, mA
without magnetic field
transverse magnetic field
longitudinal magnetic field
Fig. 7. Dependence of output current on input current
As Fig. 7 suggests, magnetic focusing increases the
upper limit of current accelerated.
SUMMARIES
It has been shown that adding magnetic focusing
yields higher output current. Magnetic focusing could
be realized by magnets made of NIB alloy. The radial
magnetic orientation is preferable.
REFERENCES
1. S.A. Vdovin, P.A. Demchenko, Ye.V. Gussev,
M.G. Shulika, O.M. Shulika. Combined Focusing in
Linear Ion Accelerator // Problems of Atomic Sci-
ence and Technology. Series “Plasma Electronics
and New Methods of Acceleration” (68). 2010, №4,
p. 325-329.
ISSN 1562-6016. ВАНТ. 2014. №3(91) 26
2. P.A. Demchenko, Ye.V. Gussev, N.G. Shulika,
O.N. Shulika, D.Yu. Zalesky. Stand for RF Gap
Breakdown Strength Study in Magnetic Field //
Problems of Atomic Science and Technology. Series
“Plasma Electronics and New Methods of Accelera-
tion” (86). 2013, №4, p. 293-296.
Article received 17.12.2013
УСКОРЯЮЩАЯ СТРУКТУРА С СОВМЕЩЕННОЙ ПЕРЕМЕННО-ФАЗОВОЙ И МАГНИТНОЙ
ФОКУСИРОВКОЙ НА ПОСТОЯННЫХ МАГНИТАХ
Е.В. Гусев, П.А. Демченко, Н.Г. Шулика, О.Н. Шулика, Д.Ю. Залеский
Предложен метод обеспечения устойчивости движения частиц в линейных ускорителях на основе ком-
бинации переменно-фазовой фокусировки и продольного магнитного поля на постоянных магнитах на базе
сплава неодим-железо-бор. Приведены результаты разработки ускоряющей структуры.
ПРИСКОРЮЮЧА СТРУКТУРА З СУМІСНИМ ЗМІННО-ФАЗОВИМ ТА МАГНІТНИМ
ФОКУСУВАННЯМ НА ПОСТІЙНИХ МАГНІТАХ
Є.В. Гусєв, П.О. Демченко, М.Г. Шуліка, О.М. Шуліка, Д.Ю. Залеський
Запропоновано метод забезпечення стійкості руху часток у лінійних прискорювачах на основі комбінації
змінно-фазового фокусування та повздовжнього магнітного поля на постійних магнітах на базі сплаву не-
одим-залізо-бор. Наведено результати розробки прискорюючої структури.
Introduction
2Tsummaries
2TReferences
УСКОРЯЮЩАЯ СТРУКТУРА С СОВМЕЩЕННОЙ ПЕРЕМЕННО-ФАЗОВОЙ И МАГНИТНОЙ ФОКУСИРОВКОЙ НА ПОСТОЯННЫХ МАГНИТАХ
Прискорююча структура з сумісним змінно-фазовим та магнітним фокусуванням на постійних магнітах
|
| id | nasplib_isofts_kiev_ua-123456789-79986 |
| institution | Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| issn | 1562-6016 |
| language | English |
| last_indexed | 2025-12-07T15:35:57Z |
| publishDate | 2014 |
| publisher | Національний науковий центр «Харківський фізико-технічний інститут» НАН України |
| record_format | dspace |
| spelling | Gussev, Ye.V. Demchenko, P.A. Shulika, N.G. Shulika, O.N. Zalesky, D.Yu. 2015-04-09T14:03:58Z 2015-04-09T14:03:58Z 2014 Accelerating structure with alternating-phase and permanent magnet focusing / Ye.V. Gussev, P.A. Demchenko, N.G. Shulika, O.N. Shulika, D.Yu. Zalesky // Вопросы атомной науки и техники. — 2014. — № 3. — С. 24-26. — Бібліогр.: 2 назв. — англ. 1562-6016 PACS: 29.20.Ej https://nasplib.isofts.kiev.ua/handle/123456789/79986 Proposed is the method for particle motion stability in linacs based on a combination of phase-alternating and longitudinal magnetic focusing using permanent magnets made of neodymium-iron-boron alloy. Presented are the results of the accelerating structure calculations. Предложен метод обеспечения устойчивости движения частиц в линейных ускорителях на основе ком-бинации переменно-фазовой фокусировки и продольного магнитного поля на постоянных магнитах на базе сплава неодим-железо-бор. Приведены результаты разработки ускоряющей структуры. Запропоновано метод забезпечення стійкості руху часток у лінійних прискорювачах на основі комбінації змінно-фазового фокусування та повздовжнього магнітного поля на постійних магнітах на базі сплаву не-одим-залізо-бор. Наведено результати розробки прискорюючої структури. en Національний науковий центр «Харківський фізико-технічний інститут» НАН України Вопросы атомной науки и техники Теория и техника ускорения частиц Accelerating structure with alternating-phase and permanent magnet focusing Ускоряющая структура с совмещенной переменно-фазовой и магнитной фокусировкой на постоянных магнитах Прискорююча структура з сумісним змінно-фазовим та магнітним фокусуванням на постійних магнітах Article published earlier |
| spellingShingle | Accelerating structure with alternating-phase and permanent magnet focusing Gussev, Ye.V. Demchenko, P.A. Shulika, N.G. Shulika, O.N. Zalesky, D.Yu. Теория и техника ускорения частиц |
| title | Accelerating structure with alternating-phase and permanent magnet focusing |
| title_alt | Ускоряющая структура с совмещенной переменно-фазовой и магнитной фокусировкой на постоянных магнитах Прискорююча структура з сумісним змінно-фазовим та магнітним фокусуванням на постійних магнітах |
| title_full | Accelerating structure with alternating-phase and permanent magnet focusing |
| title_fullStr | Accelerating structure with alternating-phase and permanent magnet focusing |
| title_full_unstemmed | Accelerating structure with alternating-phase and permanent magnet focusing |
| title_short | Accelerating structure with alternating-phase and permanent magnet focusing |
| title_sort | accelerating structure with alternating-phase and permanent magnet focusing |
| topic | Теория и техника ускорения частиц |
| topic_facet | Теория и техника ускорения частиц |
| url | https://nasplib.isofts.kiev.ua/handle/123456789/79986 |
| work_keys_str_mv | AT gussevyev acceleratingstructurewithalternatingphaseandpermanentmagnetfocusing AT demchenkopa acceleratingstructurewithalternatingphaseandpermanentmagnetfocusing AT shulikang acceleratingstructurewithalternatingphaseandpermanentmagnetfocusing AT shulikaon acceleratingstructurewithalternatingphaseandpermanentmagnetfocusing AT zaleskydyu acceleratingstructurewithalternatingphaseandpermanentmagnetfocusing AT gussevyev uskorâûŝaâstrukturassovmeŝennoiperemennofazovoiimagnitnoifokusirovkoinapostoânnyhmagnitah AT demchenkopa uskorâûŝaâstrukturassovmeŝennoiperemennofazovoiimagnitnoifokusirovkoinapostoânnyhmagnitah AT shulikang uskorâûŝaâstrukturassovmeŝennoiperemennofazovoiimagnitnoifokusirovkoinapostoânnyhmagnitah AT shulikaon uskorâûŝaâstrukturassovmeŝennoiperemennofazovoiimagnitnoifokusirovkoinapostoânnyhmagnitah AT zaleskydyu uskorâûŝaâstrukturassovmeŝennoiperemennofazovoiimagnitnoifokusirovkoinapostoânnyhmagnitah AT gussevyev priskorûûčastrukturazsumísnimzmínnofazovimtamagnítnimfokusuvannâmnapostíinihmagnítah AT demchenkopa priskorûûčastrukturazsumísnimzmínnofazovimtamagnítnimfokusuvannâmnapostíinihmagnítah AT shulikang priskorûûčastrukturazsumísnimzmínnofazovimtamagnítnimfokusuvannâmnapostíinihmagnítah AT shulikaon priskorûûčastrukturazsumísnimzmínnofazovimtamagnítnimfokusuvannâmnapostíinihmagnítah AT zaleskydyu priskorûûčastrukturazsumísnimzmínnofazovimtamagnítnimfokusuvannâmnapostíinihmagnítah |