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 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.

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.

ИМПУЛЬСНЫЕ ЛИНЕЙНЫЕ УСКОРИТЕЛИ ЭЛЕКТРОНОВ СЕРИИ ИЛУ ПРОИЗВОДСТВА ИНСТИТУТА ЯДЕРНОЙ ФИЗИКИ ИМ

The paper describes a triode RF gun for electron internal injection into the accelerating cavity. An additional RF voltage is applied to the grid-cathode unit to optimize the bunch phase characteristics. The experimental results of the gun operation to a singlecavity pulsed accelerator ILU-10 with the energy of 5 MeV and average power of 50 kW at the frequency of 116.3 MHz are presented.

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.