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.

Growing interest to product irradiation by E-beams and X-rays calls for dedicated industrial electron accelerators. BINP has developed ILU-14 radio-frequency pulsed linear accelerator capable of providing 100 kW beam at 7.5-10 MeV. The accelerator has fast removable X-ray converter and can operate both in e-beam and X-ray processing modes. The machine utilizes a low frequency (176 MHz) 6-cells SW accelerating structure. BINP developed this machine as a turn-a-key equipment. Technical details and test results will be presented.

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.

Описаны результаты численных и экспериментальных исследований по сужению энергетического спектра электронов на однорезонаторном импульсном ускорителе ИЛУ-10 (энергия электронов 5 МэВ, средняя мощность пучка 50 кВт, рабочая частота 116.3 МГц) путем подачи дополнительного внешнего высокочастотного напряжения на промежуток сетка–катод триодной высокочастотной пушки. Полученные результаты показали, что без дополнительного в.ч.-напряжения в пределах 5% энергетического разброса находится 62% мощности пучка, а при подаче дополнительного напряжения рабочей частоты в пределах этого разброса – уже 74% мощности пучка. И наконец, при дополнительном напряжении третьей гармоники в 5% энергетического разброса находится 93% мощности пучка.

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.

At Budker INP, Siberian Branch of Russian Academy of Science, a 5MeV section for high-power industrial linear electron accelerator has been tested at full voltage. The accelerator operates at 176MHz. The obtained beam-pulsed power of 2.9MW at the structure electron efficiency of 73% is close to the simulation value. Improvements of beam transportation and energy spectrum due to the injection regime optimization were experimentally proven. The paper describes the accelerating structure RF conditioning procedure and presents the results of the full voltage tests including the electron beam energy spectrum and transverse size at the accelerator output measurement results.

Results of numerical and experimental investigations of electron energy spectrum narrowing by applying an external boosting HF voltage to the grid-cathode gap of a triode HF gun in the ILU-10 single-cavity pulsed accelerator (electron energy, 5 MeV; mean beam power, 50 kW; operating frequency, 116.3 MHz) are described. These results showed that, without a booster HF voltage, 62% of the beam power is within 5% of the energy spread and, after a booster voltage of the operating frequency is applied, as much as 74% of the beam power falls within these limits. Finally, at a booster voltage of the third harmonic, 93% of the beam power lies within 5% of the energy spread.

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 ILU type industrial electron accelerators. It describes their main parameters, design, principle of action, electron beam extraction devices, wide set of auxiliary equipment for various technological processes and ways of their usage.

At Budker INP SB RAS, a prototype of high-power industrial electron accelerator for, the energy of 5 MeV, named ILU-12, has been successfully commissioned. The accelerator operates at 176 MHz. The paper presents the accelerator concept together with simulation results for the accelerating structure, beam injection and dynamics. The obtained beam pulsed power of 1,5 MW at the structure electron efficiency of 67% is close to the simulation value. Improvements of beam transportation and energy spectrum due to the injection regime optimization were experimentally proven. The results obtained are discussed.

RF gun for ILU-12 accelerator is described in the paper. Mechanism of beam transportation and energy spectrum improvements by applying an additional RF voltage of the operating frequency to the cathode-grid gap is considered in detail. Simulated energy spectrum and density profile of electron beam at the accelerator output are presented.

At Budker INP SB RAS, a prototype of high-power industrial electron accelerator for the energy of 5 MeV, named ILU-12, has been successfully commissioned. The accelerator operates at 176 MHz. The paper presents the accelerator concept together with simulation results for the accelerating structure, beam injection and dynamics. The obtained beam pulsed power of 1,5 MW at the structure electron efficiency of 67% is close to the simulation value. Improvements of beam transportation and energy spectrum due to the injection regime optimization were experimentally proven. The results obtained are discussed. PACS: 29.17+w

Design of the power input is described in the paper. The power input is a low-impedance coaxial line with the wave resistance of about 30 Ohm. One of the line ends is shorted, the other turns into the coupling loop, which inductance is compensated by the stray capacitance. The vacuum section of the power input is separated from the atmosphere by the cylindrical insulator made of 22XC ceramics. The coaxial part of the power input is divided into the 176 MHz quarter-wave-length insulator and quarter-wave-length transformer by the point of the 50 Ohm RF power feeder connection. Power input testing technique is described in the paper together with the results obtained when operating at the high power level.

In the report the review of existing methods of sterilization of medical products is submitted. The advantages of industrial accelerators in radiation technologies of sterilization are given. BINP works and results of researches on sterilization and producing of medical goods at accelerators ILU series are described. Most of investigations were spent in collaboration with various organizations.

At Budker INP SB RAS, a single module for a new 100 kW industrial accelerator with electron energy of 7.5‐ 10 MeV has been successfully tested in pulsed operating regime. The accelerator operates at 176 MHz, expected wall plug to electron energy efficiency is 25‐30%. The paper presents the accelerator concept together with simulation results for the accelerating structure, beam injection and dynamics. The obtained structure electron efficiency of 67% and average electron beam current are close to the expected values. Improvements of beam transportation and energy spectrum due to the injection regime optimization were experimentally proven. The results obtained are discussed.