Improved characteristics of HV pulse modulators for technological accelerators

The new modulator series intended to provide a pulse power supply of MI-451, MI-456 microwave magnetrons is described. The main feature of this modulator series, as compared with the existing national counterparts, is the storage charging power supply. The offered modulators with improved charging...

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Опубліковано в: :Вопросы атомной науки и техники
Дата:2004
Автори: Dolgov, A., Kildisheva, O.
Формат: Стаття
Мова:English
Опубліковано: Національний науковий центр «Харківський фізико-технічний інститут» НАН України 2004
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Цитувати:Improved characteristics of HV pulse modulators for technological accelerators / A. Dolgov, O. Kildisheva // Вопросы атомной науки и техники. — 2004. — № 2. — С. 102-104. — Бібліогр.: 4 назв. — англ.

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Digital Library of Periodicals of National Academy of Sciences of Ukraine
id nasplib_isofts_kiev_ua-123456789-79358
record_format dspace
spelling Dolgov, A.
Kildisheva, O.
2015-03-31T14:36:04Z
2015-03-31T14:36:04Z
2004
Improved characteristics of HV pulse modulators for technological accelerators / A. Dolgov, O. Kildisheva // Вопросы атомной науки и техники. — 2004. — № 2. — С. 102-104. — Бібліогр.: 4 назв. — англ.
1562-6016
PACS: 29.17.+w
https://nasplib.isofts.kiev.ua/handle/123456789/79358
The new modulator series intended to provide a pulse power supply of MI-451, MI-456 microwave magnetrons is described. The main feature of this modulator series, as compared with the existing national counterparts, is the storage charging power supply. The offered modulators with improved charging power supplies have the substantially better efficiency and high operation stability and reliability.
Описано новий ряд модуляторів, призначених для живлення імпульсною потужністю магнетронів MI- 451, MI-456. Запропоновані модулятори мають істотно кращу ефективність, високу стабільність у роботі і надійність.
Описан новый ряд модуляторов, предназначенных для питания импульсной мощностью магнетронов MI- 451, MI-456. Предлагаемые модуляторы имеют существенно лучшую эффективность, высокую стабильность в работе и надежность.
en
Національний науковий центр «Харківський фізико-технічний інститут» НАН України
Вопросы атомной науки и техники
Элементы ускорителей
Improved characteristics of HV pulse modulators for technological accelerators
ВВ імпульсні модулятори з поліпшеними характеристиками для промислових прискорювачів
ВВ импульсные модуляторы с улучшенными характеристиками для промышленных ускорителей
Article
published earlier
institution Digital Library of Periodicals of National Academy of Sciences of Ukraine
collection DSpace DC
title Improved characteristics of HV pulse modulators for technological accelerators
spellingShingle Improved characteristics of HV pulse modulators for technological accelerators
Dolgov, A.
Kildisheva, O.
Элементы ускорителей
title_short Improved characteristics of HV pulse modulators for technological accelerators
title_full Improved characteristics of HV pulse modulators for technological accelerators
title_fullStr Improved characteristics of HV pulse modulators for technological accelerators
title_full_unstemmed Improved characteristics of HV pulse modulators for technological accelerators
title_sort improved characteristics of hv pulse modulators for technological accelerators
author Dolgov, A.
Kildisheva, O.
author_facet Dolgov, A.
Kildisheva, O.
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 ВВ імпульсні модулятори з поліпшеними характеристиками для промислових прискорювачів
ВВ импульсные модуляторы с улучшенными характеристиками для промышленных ускорителей
description The new modulator series intended to provide a pulse power supply of MI-451, MI-456 microwave magnetrons is described. The main feature of this modulator series, as compared with the existing national counterparts, is the storage charging power supply. The offered modulators with improved charging power supplies have the substantially better efficiency and high operation stability and reliability. Описано новий ряд модуляторів, призначених для живлення імпульсною потужністю магнетронів MI- 451, MI-456. Запропоновані модулятори мають істотно кращу ефективність, високу стабільність у роботі і надійність. Описан новый ряд модуляторов, предназначенных для питания импульсной мощностью магнетронов MI- 451, MI-456. Предлагаемые модуляторы имеют существенно лучшую эффективность, высокую стабильность в работе и надежность.
issn 1562-6016
url https://nasplib.isofts.kiev.ua/handle/123456789/79358
citation_txt Improved characteristics of HV pulse modulators for technological accelerators / A. Dolgov, O. Kildisheva // Вопросы атомной науки и техники. — 2004. — № 2. — С. 102-104. — Бібліогр.: 4 назв. — англ.
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AT kildishevao improvedcharacteristicsofhvpulsemodulatorsfortechnologicalaccelerators
AT dolgova vvímpulʹsnímodulâtorizpolípšenimiharakteristikamidlâpromislovihpriskorûvačív
AT kildishevao vvímpulʹsnímodulâtorizpolípšenimiharakteristikamidlâpromislovihpriskorûvačív
AT dolgova vvimpulʹsnyemodulâtorysulučšennymiharakteristikamidlâpromyšlennyhuskoritelei
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last_indexed 2025-11-26T04:32:06Z
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fulltext IMPROVED CHARACTERISTICS OF HV PULSE MODULATORS FOR TECHNOLOGICAL ACCELERATORS A. Dolgov, O. Kildisheva TV and Radio Apparatus Corporation, (TIRA Corporation Ltd.) 14 Shkipersky protok, Saint-Petersburg, 199106, Russia E-mail: tira@mail.rcom.ru The new modulator series intended to provide a pulse power supply of MI-451, MI-456 microwave magnetrons is described. The main feature of this modulator series, as compared with the existing national counterparts, is the storage charging power supply. The offered modulators with improved charging power supplies have the substan- tially better efficiency and high operation stability and reliability. PACS: 29.17.+w 1. INTRODUCTION A great quantity of technological linear electron ac- celerators (LINACs) are produced in the last years for nondestructive checking, activation analysis, steriliza- tion, radiochemistry, medicine [1,2]. The requirements for these LINACs have been raised. It regards their sta- bility, operate reliability, efficiency, ease and compli- ance of operation mode change, overall dimensions and mass. All this involved also the appearance of new re- quirements for pulse modulators that serve to provide the power supply of LINACs [3]. The LINACs for the energy from 5 to 15 MeV are successfully used as radiation sources for quite a num- ber of radiation processes. The MI-451, MI-456-type magnetrons or their foreign counterparts being used as microwave devices. The new pulse-modulator series with improved characteristics intended to provide the power supply of mentioned magnetrons was designed in “TIRA Corporation” (former "Komintern"). The main parameters of the modulators are given in Table. Parameters '"MAGNETIT" modulator "PIRIT" modulator Magnetron MI-451 MI-456 Peak pulse power, MW 4.2 5.5 Peak pulse voltage, kV 45 50 Peak pulse current, А 95 110 Peak pulse current control limits, А 60-95 60-110 Flat top duration, μs 4.5 6 Pulse top Ripple, at most ±1% ±1% Current instability from pulse to pulse, at most ±0.75% ±0.75% Maximum pulse repetition rate (PRR), Hz 300 225 Maximum charging Speed, kJ/sec 10 15 The pulse modulators of this series are pulse gener- ators with a store’s full discharge and a step-up pulse transformer. They can be functionally divided into the following devices: charging power supply (CPS), pulse- forming device (PFD), pulse transformer unit (PTU). The simplified diagram of the modulator is given in Fig.1. CPS 22kV TGI1-1000/25 PFN 25 Om, 12 stage 1 : 4.55 Fig.1. Simplified diagram of the “MAGNETIT” modulator 2. PFD AND PTU The modulator output pulses are formed by the twelve-section PFN using the К75-74-type capacitors. The trimming of a pulse shape can be made off-line by changing the turns on PFN coils. The TGI1-1000/25 thyratrons are used as switch in modulators. The “MAGNETIT” modulator uses one thyratron, the “PIRIT” modulator – two thyratrons oper- ated in turns. The thyratron average current was reduced due to this approach that will permit to increase in fu- ture the pulse-repetition rate to more than 225 Hz. The additional circuits that ensure the modulator re- liability operation at load breakdowns, as well as the cir- cuits intended to reduce the pulse overshoot at leading edge and backswing, are provided in the modulator. Fig.2. PTU PTU (see Fig.2) provides, in addition to load match- ing, the power supply of the magnetron filament circuits and gun. The matching circuit, that permits to work with a cable up to 20 m long, is provided at the PTU input. The pulse transformer is demagnetized on its primary winding. ___________________________________________________________ PROBLEMS OF ATOMIC SIENCE AND TECHNOLOGY. 2004. № 2. Series: Nuclear Physics Investigations (43), p.102-104.102 The capacitance voltage divider and shunt for monit- oring the voltage shape and load current are installed at the PTU output. The modulator voltage pulse shape is shown in Fig.3. Fig.3. Modulator output voltage oscillogram (10 kV/div, 1 µs/div) 3. CPS The main feature of this modulator series is the char- ging power supply. It represents the power supply without an input line transformer and with intermediate frequency conversion. Such sources are produced in full-scale by a number of companies, but the optimum solution and reliable operation (reliability operation at high-pulse powers, reliable thyratron switching off, low cost) can be obtained only at the complex design of the modulator on the whole for specific parameters. Fig.4. CPS simplified diagram The simplified diagram of the charging power sup- ply that contains two packaged products: HF converter (HFC) and HV rectifier (HVR) - is shown in Fig.4. The HFC represents the ac-line rectifier and bridge resonance voltage converter based on IGBT transistors with access- ory circuits. It provides the conversion of a three-phase ac-line voltage applied to its input to 15...40 kHz single- phase sinusoid voltage. The HF voltage is applied to HVR unit that includes the step-up transformer and the single-phase bridge rectifier with a filter. The CPS output current and voltage control is provided at the expense of frequency control of converter operation mode. The PFN voltage oscillogram is shown in Fig.5. As it can be seen on this oscillogram, there is a pause between the thyratron switching on moment and begin- ning of the next charging cycle. It allows one to ensure the reliable thyratron switching off. The duration of this pause can be adjusted, but, as the studies have shown, 200-250 μs are sufficient for reliable TGI1-1000/25 thyratron switching off for any operation mode. After the pause has been finished, the storage char- ging begins, while the charging power supply is practic- ally operated in constant-current source mode. The char- ging current value is chosen so that the PFN voltage has time to increase up to 20...22 kV value during the pause between the pulses, even at minimum ac power line voltage (-15%) and maximum PRR. When the PFN voltage runs into the specified value, the control system provides the CPS transfer to the voltage stabilization mode in which the device can remain during long time, while compensating the PFN leakage currents. The sta- bilizing voltage value can be adjusted on-line manually or remotely by means of the analog signal within 50% to 100% of the peak value. Fig.5. Charging voltage (3.5 kV/div, 400 µs/div) This control method has a substantial advantage over the de-Q systems [4] because there is no extra energy overflow into the absorbing resistors. This permits to obtain the charging process efficiency of 92%, at least, at total control range of charging voltage, ac power line, PRR. The “PIRIT” modulator CPS outward view is shown in Fig.6. The PFN voltage oscillograms illustrat- ing the CPS system operation at ac power line voltage change within ± 15% are shown in Fig.7,a, and at char- ging voltage level control – in Fig.7,b. ___________________________________________________________ PROBLEMS OF ATOMIC SIENCE AND TECHNOLOGY. 2004. № 2. Series: Nuclear Physics Investigations (43), p.102-104.103 Fig. 6. CPS a) b) Fig.7. Charging voltage: a) at ac power line voltage change within ± 15% (3.5 kV/div., 400 μs/div.); b) at charging voltage level control change (4 kV/div, 1ms/div) 4. CONSTRUCTION As for the design, the modulators differ from each another, that was resulted from not only the different output power but also from the design task put before the designers. The main task of “MAGNETIT” design- ing was minimizing of the modulator mass-dimensions parameters. The modulator elements are placed in the common cabinet with other devices comprised in LIN- AC structure. As a result, this modulator is placed in the "Ritall" cabinet being the size of 600х800x1200 mm. The main task of “PIRIT” designing was to provide an easy access to any elements and to simplify the con- struction. The modulator is placed in the "Schroff" cabin- et having the size of 600х800х1800 mm. In addition, the modulator construction permitting to divide the cabinet into two parts has been developed, that provides its easier transportation. The modulators are made with a separate PTU that is connected by means of the KPV1/60 cable 20 m long. The PTUs represents the oil tanks having the overall dimensions of 360х580х300 mm (“MAGNETIT”), 600х350х590 mm (“PIRIT”). 5. CONCLUSIONS The described modulators at improved storage char- ging power supplies have a substantially better effi- ciency and high operation stability, providing a substan- tial increase of the consumer properties of all the tech- nological system with LINAC. The designed charging power supply allows one to provide: 1. Controlled pause after a pulse for reliable thyratron switching off; 2. Modulator output voltage control and stabilization at ac power-line voltage variation without an energy outflow into absorbing resistors; 3. Modulator output voltage control and stabilization with PRR rate variation, down to single pulses; 4. Improved mass and overall dimensions; 5. The charge efficiency not worse than 92%. REFERENCES 1. M.F.Vorogushin et al. D.V.Efremov Institutes of Electron Linacs For Applied Purposes // Voprosy Atomnoj Nauki i Tekhniki Series: Yaderno-Fi- zicheskiye Issledovaniya, 1997. 2. I.V.Shorikov et al. Compact Electron Linac for Gammagraphy // Voprosy Atomnoj Nauki i Tekh- niki Series: Yaderno-Fizicheskiye Issledovaniya, (39), 2001, v.5, p.12-14. 3. J.S. Oh et al. Development of smart modulator and efficiency evaluation of 500-GeV e+e- C-band lin- ear collider // Proceeding of LINAC200 2001, p.763-765. 4. Yu.N. Gavrish et al. Small-Size 2.5 MeV Electron Accelerator with Local Radiation Shielding // Prob- lems of Atomic Science and Technology/ Issue Nuc- lear-Physics Reseach (39). 2001, v.5, p.9-11. ВВ ИМПУЛЬСНЫЕ МОДУЛЯТОРЫ С УЛУЧШЕННЫМИ ХАРАКТЕРИСТИКАМИ ДЛЯ ПРОМЫШЛЕННЫХ УСКОРИТЕЛЕЙ А.Долгов, О. Килдишева Описан новый ряд модуляторов, предназначенных для питания импульсной мощностью магнетронов MI- 451, MI-456. Предлагаемые модуляторы имеют существенно лучшую эффективность, высокую стабильность в работе и надежность. ВВ ІМПУЛЬСНІ МОДУЛЯТОРИ З ПОЛІПШЕНИМИ ХАРАКТЕРИСТИКАМИ ДЛЯ ПРОМИСЛОВИХ ПРИСКОРЮВАЧІВ А. Долгов, О. Кілдишева 104 Описано новий ряд модуляторів, призначених для живлення імпульсною потужністю магнетронів MI- 451, MI-456. Запропоновані модулятори мають істотно кращу ефективність, високу стабільність у роботі і надійність. ___________________________________________________________ PROBLEMS OF ATOMIC SIENCE AND TECHNOLOGY. 2004. № 2. Series: Nuclear Physics Investigations (43), p.102-104.105 14 Shkipersky protok, Saint-Petersburg, 199106, Russia REFERENCES