The long-pulse multiaperture surface-plasma source with negative ion production on a cesiated grid is under construction at Budker Institute. The ion source includes RF plasma driver, an expansion chamber with multicusp magnetic filed, an external magnetic filter and a four-electrode ion-optical system for beam extraction and acceleration. The projected parameters of the ion source are: beam current 1.5 A, beam energy 120 keV, pulse duration 100 s, RF power in plasma 40 kW, hydrogen filling pressure < 0.5 Pa, e/H− ratio 1:1, H− ions emission current density 30 mA/cm2.
The CW surface-plasma source of H- ions was upgraded for increase the source lifetime and the high voltage holding. Basic improvements include the modification of magnetic system, the placement of anode collar between the dense discharge plasma region and the H- emission area, the increase of emission and ion-optical system aperture diameters and enforcing the power supplies to sustain the higher currents. Several long term runs with duration similar to 1 hour each and negative ion beam current of 25 mA were performed. Direct measurements of H- beam profile and emittance were carried out by an electric sweep scanner. No saturation of the CW H- beam current with the discharge current increase was recorded.
The results of preliminary experiments with relatively low power electron beam interacting with plasma in GDT device are discussed. The beam was injected into the device through one of the end mirrors. In the experiments, the problems related to the beam transport through the magnetic mirror were addressed.
A 1000 keV, 5 MW, 1000 s neutral beam injector based on negative ions is being developed in the Budker Institute of Nuclear Physics, Novosibirsk in collaboration with Tri Alpha Energy, Inc. The innovative design of the injector features the spatially separated ion source and an electrostatic accelerator. Plasma or photon neutralizer and energy recuperation of the remaining ion species is employed in the injector to provide an overall energy efficiency of the system as high as 80%. A test stand for the beam acceleration is now under construction. A prototype of the negative ion beam source has been fabricated and installed at the test stand. The prototype ion source is designed to produce 120 keV, 1.5 A beam.
В ИЯФ СО РАН им. Г.И. Будкера разработан новый мощный (до 100 кВт) промышленный линейный ускоритель электронов ИЛУ-14 на энергию 7.510 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 сеткакатод 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.
We proposed, manufactured and started the low-temperature plasma multicusp trap, which features filly circular geometry of magnetic field. In such plasma trap the superiority of the electron magnetic confinement over the ion confinement, and also the ion confinement in the electrical potential well are possible.
Линейный ускоритель-инжектор электронов на энергию 80 МэВ работает на стоячей волне в импульсном режиме. Ускоряющая структура с шайбами и диафрагмами на рабочую частоту 2.8 ГГц составлена из шести метровых регулярных секций с вводом мощности посредине. Пучок электронов 4 А/40 кВ/18 нс/1 Гц из диодной пушки поступает в ускоряющую структуру без предварительной группировки. В процессе ускорения он разбивается на сгустки, следующие с частотой 2.8 ГГц. По электронно-оптическому каналу из линейного ускорителя электронный пучок транспортируется на вход малого накопителя. К настоящему времени пучок электронов имеет энергию 80 МэВ и ток 80 мА с энергетическим разбросом 1% и обеспечивает непрерывную работу комплекса “Сибирь”.
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 сеткакатод 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.
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.
An 80-MeV electron linear accelerator-injector operates in a pulsed standing-wave mode. A 2.8-GHz disk-and-washer accelerating structure is composed of six 1-m-long regular sections with power input in the middle. The electron beam with parameters of 4 A/40 kV/18 ns/1 Hz from the diode gun enters the accelerating structure without prebunching. During acceleration, the beam is divided into bunches with a repetition frequency of 2.8 GHz and transported over the electron-optic channel to the booster ring. Today, the electron beam has an energy of 80 MeV, a current of 80 mA, and an energy spread of 1% and maintains continuous operation of the SIBERIA facility.
To provide basic operations of semiconductor and radiation materials technologies, a multipurpose implanter with intense ion beams was developed at the Institute of Nuclear Physics. The generated beamparameters are as follows: ions are H+, O+; C+; the ion energy is up to 200 keV; the beam current is up to 2 mA; and the implantation mode is continuous. The size of the target to be processed can reach 76 × 76 mm2. During the implanter operation, the target chamber vacuum reaches 10−4 Pa. The entire process of target irradiation is fully automated.