Self-exited generator system of RF-power supply of the one-section linear ion accelerator

The paper presents the block-diagram of a RF-power supply system of a single-section linear ion accelerator and the results of experiments on studying its mode of operation with changing the parameters of circuits of positive back couling of the radio-frequency (RF) amplifier channel.

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Published in:Вопросы атомной науки и техники
Date:2001
Main Authors: Lobzov, L.D., Shulika, N.G.
Format: Article
Language:English
Published: Національний науковий центр «Харківський фізико-технічний інститут» НАН України 2001
Online Access:https://nasplib.isofts.kiev.ua/handle/123456789/79007
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Cite this:Self-exited generator system of RF-power supply of the one-section linear ion accelerator / L.D. Lobzov, N.G. Shulika // Вопросы атомной науки и техники. — 2001. — № 5. — С. 157-159. — Бібліогр.: 6 назв. — англ.

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Digital Library of Periodicals of National Academy of Sciences of Ukraine
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author Lobzov, L.D.
Shulika, N.G.
author_facet Lobzov, L.D.
Shulika, N.G.
citation_txt Self-exited generator system of RF-power supply of the one-section linear ion accelerator / L.D. Lobzov, N.G. Shulika // Вопросы атомной науки и техники. — 2001. — № 5. — С. 157-159. — Бібліогр.: 6 назв. — англ.
collection DSpace DC
container_title Вопросы атомной науки и техники
description The paper presents the block-diagram of a RF-power supply system of a single-section linear ion accelerator and the results of experiments on studying its mode of operation with changing the parameters of circuits of positive back couling of the radio-frequency (RF) amplifier channel.
first_indexed 2025-12-07T18:27:03Z
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fulltext SELF-EXITED GENERATOR SYSTEM OF RF -POWER SUPPLY OF THE ONE-SECTION LINEAR ION ACCELERATOR L.D. Lobzov, N.G. Shulika NSC KIPT, Kharkov, Ukraine The paper presents the block-diagram of a RF-power supply system of a single-section linear ion accelerator and the results of experiments on studying its mode of operation with changing the parameters of circuits of positive back couling of the radio-frequency (RF) amplifier channel. PACS number: 29.17.+w The development of a high-stable self-exiting gener- ator system of RF-power supply with a minimum num- ber of amplifier stages for the accelerator MLUD-3, when upgrading its accelerating structure [1], was dic- tated by a number of advantages, which are considered to be characteristic for self-excited oscillation systems [2]. However, introduction of one positive back coupling (any), for energization of the amplifier channel, during correlation of the amplitude-phase relations in an self- excited oscillator circuit, did not provide its steady oper- ation, because of a multipactor action being developed in the accelerator. Attempts to use the experts’ experi- ence accumulated in the field of development of similar systems [3] did not give the needed results because of features inherent in accelerating structures with vari- able-phase focusing on the comb-shaped holders of drift tubes and operation at H- mode oscillation [4]. Fig. 1. Block diagram of the self-excited generator of RF power supply of the single-section linear ion accelerator. 1 – amplifier channel; 2 – loop of power supply; 3 - resonator; 4 – loop of the first positive back cou- pling; 5 – loop of the second positive back coupling; 6 – summarizing device; 7 – attenuator; 8 - phase changer; 9 – feeder commutator; 10 – feeder reflec- tometer; 11 – resistance; 12 – measuring loop. Usage of superpositions of two positive back cou- pling (the loop of one of them is placed in the accelera- tor resonator, and the loop of another is in the feeder of a power at which induced is the voltage proportional to the amplitude of an incident wave) allows to create a self-excited generator system of the RF-power supply of the accelerator effectively overcoming the multipactor effects and providing the steady operation of the ampli- fier channel and the accelerator in a whole [5, 6]. It is explained by the fact, that the mode of self-excited gen- eration in the second circuit does not depend on the pro- cesses acting in the resonator, into which an appropriate part of a power arrives, providing violation of multi- pactor phenomena conditions. This paper presents the results of investigations per- formed at the accelerator MLUD-3, taking into account the changes of some parameters of its self-excited gen- erator system of RF-power supply. The block-diagram of the self-excited generator sys- tem of RF-power supply of the single-section linear ion accelerator used for investigations is shown in Fig. 1. The three-stage amplifier channel, with the amplifi- cation factor (~100) chosen taking into account the pro- vided amplitude relations of the self-excited generation system, is covered by two positive back coupling, the signals of which are controlled by continuous attenua- tors and phase changers. The perturbation of accelerat- ing fields entered into its resonator by a loop of positive back coupling does not exceed the value 1%. The control of power mode transmission into the ac- celerator is made with measurement of a signal ampli- tude from the resonator and with measurement of inci- dent and back wave amplitudes, both in a power feeder, and in circuits of positive back coupling. The accelerator resonance frequency in a pulse mode is measured with the help of the equipment, comprising a frequency mixer, generator, frequency counter and os- cillograph. The frequencies of self-excited oscillations at each of circuits are determined by a frequency of a high-Q resonator of the accelerator (Qres ≈ 5000). The study of the influence of the first positive back coupling (FPBC) and the second positive back coupling (SPBC) circuits together with their loops, placed, in correspond- ing points at a resonance frequency of the accelerator, was conducted in the mode of "cold" measurements. Within the accuracy of measurements ±5 kHz the reso- nance frequency of the accelerator does not vary when connecting both together, and separately the indicated circuits, that is confirmed by the "weakness" of their in- fluence on electrodynamics parameters of the accelera- tor. Study of the relation of amplitudes of FPBC and ВОПРОСЫ АТОМНОЙ НАУКИ И ТЕХНИКИ. 2001. №5. Серия: Ядерно-физические исследования (39), с. 157-159. 157 SPBC signals in an operation mode of the accelerator have allowed to install the value of a SPBC signal in limits (0.1÷0.3) of the first positive back coupling am- plitude, when simultaneously a high-stability operation of the accelerator is provided, and the value of an accel- erating field is determined by a signal amplitude from the resonator. In the plots (Fig. 2-Fig. 5) shown are the dependen- cies of basic parametres of the accelerator for changing, in limits ±90°, the phase of positive back coupling of one of circuits, while another circuit has an optimum phase tuning. Fig. 2. Voltage amplitude of incident and back waves in feeder power supply as a function of back coupling signal phases: 1 – Uinc = f(ϕFPBC); 2 - Uinc = f(ϕSPBC); 3 – Uback = f(ϕFPBC); 4 - Uback = f(ϕSPBC). Fig. 3. Voltage amplitude with resonator measuring loop as a function of back coupling phases: 1 - Ures = f(ϕFPBC); 2 – Ures = f(ϕSPBC). From the dependencies observed it follows that the required parameters of the accelerator describing the mode of matched power transmission into the accelera- tor, are supported by phase control in circuits of positive back couplings in limits (1÷2)°. The change of the matching degree is controlled by the back wave ampli- tude in a power feeder and together with measurements of basic parameters determines the operation mode of the accelerator. Fig. 4. Voltage standing wave rate in feeder power supply as a function of back coupling signal phases: 1 – SWR = f(ϕFPBC); 2 – SWR nc = f(ϕSPBC). Fig. 5. Basic frequency of the resonator accelerator as a function of back coupling signal phases: 1 - Fres = f(ϕFPBC); 2 – Fres = f(ϕSPBC). The present research allows one to determine the re- quirements for design of automatic controls stabilizing the amplitude and accelerating field phase in the accel- erator, that will facilitate the maintenance of the acceler- ator and essentially will increase the reliability of its op- eration. REFERENCES 1. A.S.Beley et al. Project of upgrading the accelerat- 158 ing structure of a small-size linear deuton accelera- tor // Voprosy atomnoj Nauki i Tekhniki. Ser.: Tekhnika fizicheskogo ehksperimenta. (35). 1987, v. 4, p. 8 (in Russian). 2. Linear Ion Accelerators. v. 2 / Edited by B.P.- Murin, Moscow, Atomizdat, 1978, 144 p. (in Rus- sian). 3. V.A.Popov. System of radio-frequency excitation of JINR LU-20 Synchrotron. Preprint 9-11835, DUB- NA, 1978. 4. L.N.Baranov et al. Experimental research of the small-sized linear accelerator of the 3 MeV deuton energy 3 MeV with variable-phase focusing // Vo- prosy atomnoj Nauki i Tekhniki. Ser.; Linejnye uskoriteli (5). 1977, v. 2, p. 12 (in Russian). 5. L.D.Lobzov et al. Radio-frequency self-excited generator. License SU N1700783 A1, Bull. of in- vention N 47, 1991, p. 239 (in Russian). 6. L.D.Lobzov et al. RF self-excited generator of the linear ion accelerator // XII All-Union Workshop of Linear Accelerators of Charged Particles (Kharkov, May 28-30, 1991), Abstracts, p. 51 (in Russian). ВОПРОСЫ АТОМНОЙ НАУКИ И ТЕХНИКИ. 2001. №5. Серия: Ядерно-физические исследования (39), с. 159-159. 159
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institution Digital Library of Periodicals of National Academy of Sciences of Ukraine
issn 1562-6016
language English
last_indexed 2025-12-07T18:27:03Z
publishDate 2001
publisher Національний науковий центр «Харківський фізико-технічний інститут» НАН України
record_format dspace
spelling Lobzov, L.D.
Shulika, N.G.
2015-03-24T17:13:59Z
2015-03-24T17:13:59Z
2001
Self-exited generator system of RF-power supply of the one-section linear ion accelerator / L.D. Lobzov, N.G. Shulika // Вопросы атомной науки и техники. — 2001. — № 5. — С. 157-159. — Бібліогр.: 6 назв. — англ.
1562-6016
PACS number: 29.17.+w
https://nasplib.isofts.kiev.ua/handle/123456789/79007
The paper presents the block-diagram of a RF-power supply system of a single-section linear ion accelerator and the results of experiments on studying its mode of operation with changing the parameters of circuits of positive back couling of the radio-frequency (RF) amplifier channel.
en
Національний науковий центр «Харківський фізико-технічний інститут» НАН України
Вопросы атомной науки и техники
Self-exited generator system of RF-power supply of the one-section linear ion accelerator
Система автогенератора высокочастотного источника питания односекционного линейного ускорителя ионов
Article
published earlier
spellingShingle Self-exited generator system of RF-power supply of the one-section linear ion accelerator
Lobzov, L.D.
Shulika, N.G.
title Self-exited generator system of RF-power supply of the one-section linear ion accelerator
title_alt Система автогенератора высокочастотного источника питания односекционного линейного ускорителя ионов
title_full Self-exited generator system of RF-power supply of the one-section linear ion accelerator
title_fullStr Self-exited generator system of RF-power supply of the one-section linear ion accelerator
title_full_unstemmed Self-exited generator system of RF-power supply of the one-section linear ion accelerator
title_short Self-exited generator system of RF-power supply of the one-section linear ion accelerator
title_sort self-exited generator system of rf-power supply of the one-section linear ion accelerator
url https://nasplib.isofts.kiev.ua/handle/123456789/79007
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