The design and principle of operation of ILU-series industrial electron accelerators produced by the Budker Institute of Nuclear Physics are considered using the examples of the ILU-10 accelerator with an accelerated-electron energy of 5 MeV and a mean beam power as high as 50 kW and the ILU-14 accelerator with an electron energy of up to 10 MeV and a beam power as high as 100 kW. The mechanisms of interaction between the electron beam and microbiological samples, the peculiarities of the depth profile of the absorbed dose in a substance, and the design of the electron-beam converter into bremsstrahlung are described. By using this converter, it is possible to increase the mass thickness of treated products several times compared to the electron mode. The throughput of ILU accelerators during radiation sterilization and electron pasteurization of products is estimated.

В данной работе представлены расчеты систем выпуска и поворота электронного пучка, разработанных для импульсных ускорителей электронов серии ИЛУ за последние годы. В частности, описана система сканирования пучка, отличительной особенностью которой от предыдущих аналогов является введение коррекции формы сканирующего магнитного поля. Приведены результаты испытаний данной системы на ускорителе ИЛУ-10 (5 МэВ, 50 кВт). Рассмотрена система выпуска пучка для ускорителя ИЛУ-14 (10 МэВ, 100 кВт), содержащая систему фокусировки пучка и коррекции его оси после выхода из ускоряющей структуры, а также выпускное устройство, позволяющее увеличить ширину сканирования пучка до 160 см. Также в работе описана система для поворота немонохроматичных электронных пучков, состоящая из двух магнитных зеркал, позволяющая компенсировать угловые расходимости пучка и получать после поворота электронный пучок с фазовыми характеристиками близкими к начальным. Приведены экспериментальные данные поворота электронного пучка на 180º.

В статье представлена работа стерилизационного комплекс ИЯФ СО РАН - НГУ созданного на территории ИЯФ СО РАН. Приводятся технические решения и параметры облучаемой продукции и дозные распределения. Так же представлены работы по отработке технологии стерилизации медицинских изделий. Затронуты вопросы обработки пищевых продуктов ионизирующим излучением. Представлены совместные с медиками новые разработки в области имплантологии и разработки нового биорезорбируемого гелевого носителя на основе хитозана.

The device and principle of operation of the pulse modulator, which is the power-supply system for the ILU series accelerators, as well as some features that arise during its operation, are described. The modulator is a device that is a nonlinear load for the supply network, as a result of which, in all phases of the supply network, an asymmetry of the current form occurs over the period of the network. This leads to the appearance of a constant current component in the phases of the supply transformer. To solve this problem, current balancing of the start time of modulators was proposed. Using this method, it is also possible to equalize the values of effective currents in phases. Another problem is the possibility of the appearance of higher harmonics in relation to the supply frequency in the phases of the power-supply network. To reduce the values of higher harmonics, it is proposed to install additional inductances in each phase of the power-supply network up to the modulator, which makes it possible to reduce the harmonic coefficient by half.

A pulsed power supply based on capacitive storage with a partial discharge for high-frequency pulsed linear electron accelerators of the ILU type is described. The maximum output pulse voltage of the source is 36 kV at a load current of up to 250 A and a pulse duration of up to 1 ms, and a pulse repetition rate of up to 100 Hz. The source is built according to a relatively simple modular scheme and consists of ten modules connected in series. It was assembled and tested with a load connection in one module. The circuit provides uniform current consumption in all phases of a 380 V three-phase supply network.

A system for rotating nonmonochromatic electron beams consisting of two identical magnetic mirrors, is described. The distribution of the magnetic field along the depth of the mirrors is formed in such a way that an increase in the magnetic field at the entrance to the mirror follows its decline according to a certain law. As a result, it is possible to compensate for the angular divergences of nonmonochromatic electron beams in the gaps of the mirrors and to obtain a beam with phase characteristics close to the initial ones after rotation. Calculations and experimental test data of such a device are given when the electron beam is rotated through 180°.

Pulse linear electron accelerators of the ILU type have been developed and produced by the Institute of Nuclear Physics, Siberian Branch, Russian Academy of Sciences, for more than 30 years. Their distinctive features are simplicity of design, convenience in operation, and reliability during long work under conditions of industrial production. ILU accelerators have a range of energy of 0.7–10 MeV at a power of accelerated beam of up to 100 kW and they are optimally suitable for use as universal sterilizing complexes. The scientific novelty of these accelerators consists of their capability to work both in the electron-treatment mode of production and in the bremsstrahlung generation mode, which has high penetrating power.

В ИЯФ СО РАН им. Г.И. Будкера разработан новый мощный (до 100 кВт) промышленный линейный ускоритель электронов ИЛУ-14 на энергию 7.5–10 МэВ. Рабочая частота ускорителя 176 МГц, полный к.п.д. 26%. Ускоритель имеет модульную структуру, что позволяет путем изменения модульной комплектации менять в определенных пределах энергию электронов и мощность в пучке. В настоящее время изготовлен и успешно прошел испытания прототип этого ускорителя. В экспериментах подтверждены расчетные параметры: энергия 5 МэВ, средний за в.ч.-период ток пучка 600 мА, импульсная мощность пучка 2.5 МВт и электронный к.п.д. ускоряющей структуры 68%. Благодаря подаче дополнительного в.ч.-напряжения на зазор сетка–катод пушки достигнуто токопрохождение электронного пучка 96% и получен малый энергетический разброс пучка. Прототип ускорителя ИЛУ-14 может быть использован как самостоятельный ускоритель с мощностью в пучке 50 кВт.

This paper describes the industrial electron accelerators of the ILU type and their usage for sterilization. The ILU machines produced by Budker Institute of Nuclear Physics have energy range of 0.8-10 MeV and beam power up to 100 kW, and they are working in industries all over the world. The ILU-10 and ILU-14 machines are described as well as the industrial sterilization facility based on ILU-6, ILU-10 and ILU-14 machines.

A new high-power (up to 100 kW) industrial electron linear accelerator ILU-14 for energies of 7.5–10.0 MeV has been developed by the Budker Institute of Nuclear Physics. The operating frequency of the accelerator is 176 MHz, and the total efficiency is 26%. Owing to the modular structure of the accelerator, the electron energy and the beam power can be varied within certain limits by changing the modular arrangement. A 5-MeV prototype of this accelerator has been produced and successfully tested. Its design parameters verified in the experiments are as follows: the beam current averaged over the RF period is 600 mA, the beam pulse power is 2.5 MW, and the electron efficiency of the accelerating structure is 68%. By applying an additional RF voltage to the electron gun cathode-grid gap, a 96% transmittance of the beam current has been attained at a minor beam energy spread. The prototype of the ILU-14 accelerator can be used as an accelerator with a beam power of 50 kW.

A new high power (up to 100 kW) industrial linear electron accelerator ILU-14 for energy of 7.5–10 MeV is under construction at Budker INP. The accelerator operates at 176 MHz with total efficiency of 26 %, its modular structure allows the electron energy and beam current to be varied within certain limits by changing the modular arrangement. The 5 MeV prototype of the accelerator was created and successfully tested in 2009. The designed average beam current of 600 mA with pulsed power of 2.5 MW and accelerating structure electron efficiency of 68 % were obtained during experiments. Applying an additional RF voltage to the electron gun cathode-grid gap allowed a beam current passing of 96 % with minor beam energy spread. The paper presents results of the numerical and experimental study of the accelerator systems together with the latest tests on the accelerator prototype.

An ILU-8 single-cavity electron linear accelerator has been designed for use in industrial radiation technology systems for electron irradiation of materials and products. Experimental data of accelerator adjustment and results of measurements of the accelerated beam parameters in modes characteristic of industrial applications are presented. The main parameters of the accelerator are as follows: the electron energies are 0.7–1.0 MeV and the beam power is 20 kW at an average current of up to 25 mA. The accelerator operates in a pulsed mode: the pulse duration is 800 μs, and the pulse repetition frequency is 50 (60) Hz. The cavity is excited by a single-stage self-excited oscillator based on a GI-50A tube with feedback via the cavity at a frequency of 175.6 MHz. The accelerating cavity, together with a system of beam extraction into the atmosphere, can be located inside the biological shielding composed of steel slabs with a total mass of 76 t.

Однорезонаторный линейный ускоритель электронов ИЛУ-8 предназначен для облучения электронами материалов и изделий в составе радиационно-технологических установок промышленного назначения. Приведены экспериментальные данные по наладке ускорителя и измерению параметров ускоренного пучка для режимов промышленного применения. Основные параметры ускорителя: энергия электронов 0.7–1.0 МэВ, мощность пучка 20 кВт при среднем токе до 25 мА. Режим работы импульсный: длительность импульсов 800 мкс, частота повторения импульсов 50(60) Гц. Возбуждение резонатора осуществляется от однокаскадного автогенератора на лампе ГИ-50А с обратной связью через резонатор на частоте 175.6 МГц. Ускоряющий резонатор с системой выпуска пучка в атмосферу может быть размещен внутри биологической защиты из стальных плит общей массой 76 т.

The report describes electron beam electromagnetic forming system, which is destined for irradiation of cylindrical long goods, specifically for PE tubes 160mm diameter. System consists of electromagnet, power supply units, beam distributions control units, etc. for use at an electron accelerator at 5MeV and 50kW. The particular geometry of the magnet poles and their mutual arrangement are creating an irradiation field that allows the electrons to irradiate the surface of the product close to 90°.

The report describes the industrial electron accelerator ILU-10 for electron energy up to 5 MeV and beam power up to 50 kW specially designed for use in industrial applications. The operation regime is a pulsed regime, the maximum pulse repetition rate is 50 (60) Hz, a pulse duration is 0.4-0.5 ms.

The converters were designed for generation of intensive bremsstrahlung radiation. The powerful electron beam (5MeV, 50kW) was generated by ILU-10 accelerator. The converters differ in technology of manufacturing and material of target, tungsten carbide or tantalum. The aluminum board with the channels for cooling water is used as the base of the converter and filter for low energy part of bremsstrahlung spectrum. The converters can be installed in vacuum or outside the accelerator in air under the beam window. The results of testing of different converters are given.

To improve performance reliability of the ELIT-3A installation a new 19-beam electron gun with total diameter of the cathode 46 mm has been developed, constructed, and put into operation. Parameters of the accelerator are: - current 50 A; - electron energy 1.65 MeV; - pulse duration 11 µsec. During operation the multy-beam gun showed some essential advantages, namely: - the flow of electrons on electrodes is decreased considerably, that in turn has reduced number of break-downs in accelerating tube by order; - life-time of the gun is extended minimum 5 times due to lessening of the cathode current density; - new calculated optics allowed one to reduce the number of focusing magnetic lenses in the tube to single one compared to three required before. Being in exploitation for more than 5500 hours the gun reveals almost better emission characteristics than at the beginning. In the paper one can find more detailed description of the gun itself as well as results of experiment at ELIT.