The tuning method of the biperiodic accelerating structure of electron linear accelerator
Providing the operating mode of the accelerating structure requires controlling the resonant frequencies and coupling coefficients between the cells. Single cell of the accelerating structure is the high quality resonator. For the cell fine-tuning it is necessary to observe the boundary conditions g...
Saved in:
| Date: | 2001 |
|---|---|
| Main Authors: | , , |
| Format: | Article |
| Language: | English |
| Published: |
Національний науковий центр «Харківський фізико-технічний інститут» НАН України
2001
|
| Series: | Вопросы атомной науки и техники |
| Online Access: | http://dspace.nbuv.gov.ua/handle/123456789/79209 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| Journal Title: | Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| Cite this: | The tuning method of the biperiodic accelerating structure of electron linear accelerator / I.O. Chetverikov, D.V. Slyusar, V.V. Terent’ev // Вопросы атомной науки и техники. — 2001. — № 3. — С. 99-100. — Бібліогр.: 1 назв. — англ. |
Institution
Digital Library of Periodicals of National Academy of Sciences of Ukraine| id |
irk-123456789-79209 |
|---|---|
| record_format |
dspace |
| spelling |
irk-123456789-792092015-03-30T03:01:54Z The tuning method of the biperiodic accelerating structure of electron linear accelerator Chetverikov, I.O. Slyusar, D.V. Terent’ev, V.V. Providing the operating mode of the accelerating structure requires controlling the resonant frequencies and coupling coefficients between the cells. Single cell of the accelerating structure is the high quality resonator. For the cell fine-tuning it is necessary to observe the boundary conditions given by presence neighbor cells. In this paper the description of arrangement modeling these boundary conditions and the methods of frequency and coupling coefficients measuring are presented. The developed methods are universal for tuning of the biperiodic linear accelerator structures, which have different operating frequencies. 2001 Article The tuning method of the biperiodic accelerating structure of electron linear accelerator / I.O. Chetverikov, D.V. Slyusar, V.V. Terent’ev // Вопросы атомной науки и техники. — 2001. — № 3. — С. 99-100. — Бібліогр.: 1 назв. — англ. 1562-6016 PACS numbers: 29.17.+w http://dspace.nbuv.gov.ua/handle/123456789/79209 en Вопросы атомной науки и техники Національний науковий центр «Харківський фізико-технічний інститут» НАН України |
| institution |
Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| collection |
DSpace DC |
| language |
English |
| description |
Providing the operating mode of the accelerating structure requires controlling the resonant frequencies and coupling coefficients between the cells. Single cell of the accelerating structure is the high quality resonator. For the cell fine-tuning it is necessary to observe the boundary conditions given by presence neighbor cells. In this paper the description of arrangement modeling these boundary conditions and the methods of frequency and coupling coefficients measuring are presented. The developed methods are universal for tuning of the biperiodic linear accelerator structures, which have different operating frequencies. |
| format |
Article |
| author |
Chetverikov, I.O. Slyusar, D.V. Terent’ev, V.V. |
| spellingShingle |
Chetverikov, I.O. Slyusar, D.V. Terent’ev, V.V. The tuning method of the biperiodic accelerating structure of electron linear accelerator Вопросы атомной науки и техники |
| author_facet |
Chetverikov, I.O. Slyusar, D.V. Terent’ev, V.V. |
| author_sort |
Chetverikov, I.O. |
| title |
The tuning method of the biperiodic accelerating structure of electron linear accelerator |
| title_short |
The tuning method of the biperiodic accelerating structure of electron linear accelerator |
| title_full |
The tuning method of the biperiodic accelerating structure of electron linear accelerator |
| title_fullStr |
The tuning method of the biperiodic accelerating structure of electron linear accelerator |
| title_full_unstemmed |
The tuning method of the biperiodic accelerating structure of electron linear accelerator |
| title_sort |
tuning method of the biperiodic accelerating structure of electron linear accelerator |
| publisher |
Національний науковий центр «Харківський фізико-технічний інститут» НАН України |
| publishDate |
2001 |
| url |
http://dspace.nbuv.gov.ua/handle/123456789/79209 |
| citation_txt |
The tuning method of the biperiodic accelerating structure of electron linear accelerator / I.O. Chetverikov, D.V. Slyusar, V.V. Terent’ev // Вопросы атомной науки и техники. — 2001. — № 3. — С. 99-100. — Бібліогр.: 1 назв. — англ. |
| series |
Вопросы атомной науки и техники |
| work_keys_str_mv |
AT chetverikovio thetuningmethodofthebiperiodicacceleratingstructureofelectronlinearaccelerator AT slyusardv thetuningmethodofthebiperiodicacceleratingstructureofelectronlinearaccelerator AT terentevvv thetuningmethodofthebiperiodicacceleratingstructureofelectronlinearaccelerator AT chetverikovio tuningmethodofthebiperiodicacceleratingstructureofelectronlinearaccelerator AT slyusardv tuningmethodofthebiperiodicacceleratingstructureofelectronlinearaccelerator AT terentevvv tuningmethodofthebiperiodicacceleratingstructureofelectronlinearaccelerator |
| first_indexed |
2025-07-06T03:15:57Z |
| last_indexed |
2025-07-06T03:15:57Z |
| _version_ |
1836865822451040256 |
| fulltext |
THE TUNING METHOD OF THE BIPERIODIC ACCELERATING
STRUCTURE OF ELECTRON LINEAR ACCELERATOR
I.O. Chetverikov, D.V. Slyusar, V.V. Terent’ev
NIIEFA D.V. Efremov Scientific Research Institute of Electrophysical Apparatus
St-Petersburg, Metallostroy, Ave. Sovetsky 1, Russia
e-mail: NPK LUTS @ NIIEFA. SP.SU
Providing the operating mode of the accelerating structure requires controlling the resonant frequencies and cou-
pling coefficients between the cells. Single cell of the accelerating structure is the high quality resonator. For the cell
fine-tuning it is necessary to observe the boundary conditions given by presence neighbor cells. In this paper the de-
scription of arrangement modeling these boundary conditions and the methods of frequency and coupling coeffi-
cients measuring are presented. The developed methods are universal for tuning of the biperiodic linear accelerator
structures, which have different operating frequencies.
PACS numbers: 29.17.+w
1 INTRODUCTION
To obtain more effective using of the accelerating
structure length and to provide the operating mode of
the accelerating structure it is necessary to control the
resonant frequencies and coupling coefficients between
the cells. It is desirable that the frequency detuning of
one cell was less than 0.01%. At present the calculations
with such small errors are not possible.
To achieve this high frequency precision of the man-
ufactured cells, it is necessary to carry out correct mea-
surement at the constant temperature and proper me-
chanical pressure for guarantee of good contact between
the metal surface.
The measurements of the amplitude field ratios in
the accelerating structure are made for tuning of the
coupling slots. Especially it is important in the buncher
part of the accelerating structure to achieve required
bunch parameters.
In that way, the tuning of cell frequencies and cou-
pling coefficients of linear electron accelerator cells is a
long process with a lot of measurements.
2 THE METHOD OF CELL FREQUEN-
CY TUNING
The first step of the cell tuning procedure on the op-
erating frequency is a measurement at resonant frequen-
cy of the cell. Having been defined cell resonant fre-
quency inner diameter is machining for decreasing fre-
quency on the corresponding value. Such manner of the
tuning procedure presumes that at the beginning of the
tuning there is some frequency reserve. The reserve is
diminished in the series machining of the inner diame-
ter. The initial reserve is determined by calculating error
value and it is 20 MHz [1].
The basic problem of this tuning scheme is the fre-
quency measuring phase. The accelerating structure cell
is the high quality resonator. The precision tuning of
cell resonant frequency requires to meet the boundary
conditions, which are formed by influence of the neigh-
bor cells of the resonator tested. Thus, it is necessary to
develop the measurement methods, which will simulate
such boundary conditions and allow to measure fre-
quencies of a separate cell or assembly of cells at low
power level.
The suggested scheme of the accelerating structure
cell measurements is shown in Fig. 1a. Neighbor cells
(2, 4) directly define the boundary condition for the
measuring cell (3). Because of the shorting cylinder
there is no resonance in the neighbor cells. The influ-
ence of the coupling slots on the resonant frequency is
the same as inside the real structure. Hence separate cell
frequencies are measured.
3 THE METHOD OF COUPLING COEFFI-
CIENTS TUNING
A method of coupling coefficients tuning in the ac-
celerator is rather difficult. Coupling coefficients are
tuned by pairs in each cascade. Successful tuning
provides optimal field ratios in the accelerator cells.
The field ratios along the main part of accelerating
structure are equal to 1. That occurs when the slots in
cascade have the same lengths, and in this case the tun-
ing is not difficult. Problems arise in the injector area,
where the amplitude ratio between successive accelerat-
ing cavities can be as high as 4 A permissible tolerance
of the field value is about 2%. This tolerance is much
higher than that of frequency, but even this error re-
quires a number of measurements and coupling slot ad-
justments to be performed before it can be achieved.
The measurement scheme of the coupling slots in
the accelerating structure is shown in Fig. 1b. The small
metal bead (5) is inserted into the cascade of the cells
(2, 3, 4) and detunes the cascade resonant frequency.
The ratio of the frequency deviation when detuning met-
al bead move along the cascade axis defines the field
amplitude ratio.
4 CONCLUSION
Suggested measurement scheme is universal one for
a resonator tuning of the biperiodic and combined accel-
erating structures operating in the π/2 mode in the wide
frequency range. It allows with great accuracy to model
boundary conditions stipulated by the influence of the
neighbour cells on the resonator frequency, and to re-
ВОПРОСЫ АТОМНОЙ НАУКИ И ТЕХНИКИ. 2001. №3.
Серия: Ядерно-физические исследования (38), с. 99-100.
99
duce to a minimum errors, caused by feeding and meas- urement devices.
Fig. 1a. The scheme of frequency measure-
ment of single cell (1 ,2, 4 – neighbor cells,
3 –cell testied, 5 – shorting cylinders, 6 – ab-
sorbing cavities coated by alsifer, 7 – analyz-
er).
Fig. 1b. The measurement scheme of the cou-
pling coefficient in the accelerating structure
(1 – neighbor cell, 2, 3, 4 – cells of cascade
tested, 5 – small metal detuning bead on the
thread, 6 – absorbing cavities coated by al-
sifer, 7 – analyzer).
The developed method of the frequency tuning is
successfully employed in production of the different
types of the accelerators. This method for tuning RF-
parameters of the accelerator makes manufacture pro-
cess faster and allows to improve quality of the produc-
tion. Measured parameters of the accelerating structures
at high power level are found to be in a good agreement
with the results obtained via field distribution and beam
dynamics simulation for self-consisted high frequency
fields.
REFERENCES
1. I.O.Chetverikov, O.L.Maslennikov, V.V.Terent’ev.
Using the Finite Element Method while Design the
Linear Accelerator Structure // Proc. XVII All-Rus-
sia Workshop on Charged Particle Accelerators,
Protvino, 2000. (in Russian).
100
|