This paper reports on the design features and construction progress of the three RF systems for the NICA collider being built at JINR, Dubna. Each of the two collider rings has three RF systems named RF1 to 3. RF1 is a barrier bucket system used for particles capturing and accumulation during injection, RF2 and 3 are resonant systems operating at 22nd and 66th harmonics of the revolution frequency and used for the 22 bunches formation. The RF systems are designed and produced by Budker INP. Solid state RF power amplifiers developed by the Triada-TV company, Novosibirsk, are used for driving the RF2 and 3 cavities. Two RF1 stations were already delivered to JINR, the prototypes of the RF2 and 3 stations were built and successfully tested at BINP. Series production of all eight RF2 and sixteen RF3 stations is in progress. The design modifications and test results are presented.

The Novosibirsk FEL facility has three FELs installed on the first, second, and fourth orbits of the multiturn energy recovery linac (ERL). The first FEL covers the 90–240 μm range of wavelengths at an average radiation power of 0.5 kW with a pulse repetition rate of 5.6 or 11.2 MHz and a peak power of 1 MW. The second FEL operates in the 40–80 μm range of wavelengths at an average radiation power of 0.5 kW with a pulse-repetition rate of 7.5 MHz and a peak power of around 1 MW. These two FELs are the world’s most powerful (in terms of average power) sources of coherent narrow-band (less than 1%) radiation in their wavelength ranges. The third FEL was commissioned in 2015 to cover the 5–20 μm range of wavelengths. The Novosibirsk ERL is the world’s first and only multiturn ERL. Its distinctive features include a normally-conductive 180 MHz accelerating system, a direct current (DC) electrostatic electron gun with a control grid and thermionic cathode, three operating modes of the magnetic system, and a compact (6 × 40 m) design. The Novosibirsk FEL facility has been in operation for users of terahertz radiation since 2004.

The new NICA (Nuclotron-based Ion Collider fAсility) accelerator complex being built at the Joint Institute for Nuclear Research (Dubna, Russia) is intended for experiments with 197Au79+ gold nuclei at energies in the range of 1–4.5 GeV/n. The RF system of the collider should provide the capture of bunches to be injected from the nuclotron, the accumulation of the necessary number of particles, their acceleration (if necessary), and the formation of bunches. For this, in each ring of the collider, three types of accelerating stations are used: one barrier station and two harmonic stations. The barrier station accumulates the particles and can used to accelerate them up to the energy of the experiment. The harmonic RF stations operating at the 22th and 66th harmonics of the revolution frequency are used for the formation of bunches. This paper describes the operating modes of the RF system and the design features of the RF stations.

Free electron lasers (FELs) are unique sources of electromagnetic radiation with tunable wavelength. A high-power FEL has been created at the G. I.Budker Institute for Nuclear Physics. Its radiation frequency can be tuned over a wide range in the terahertz and infrared spectral ranges. As the source of electron bunches, this FEL uses a multi-turn energy-recovery linac, which has five straight sections. Three sections are used for three FELs which operate in different wavelength ranges (90–240 μm for the first, 37–80 μm for the second, and 5–20 μm for the third ones). The first and the second FELs were commissioned in 2003 and 2009, respectively. They are used for various applied and research problems now. The third FEL is installed on the last, forth accelerator loop, in which the electron energy is the maximum. It comprises three undulator sections and a 40 m optical cavity. The first lasing of this FEL was obtained in the summer of 2015. The radiation wavelength was 9 μm and the average power was about 100 W. The design power is 1 kW at a pulse repetition rate of 3.75 MHz. Radiation of the third FEL will be delivered to user stations from the protected hall in the near future. The third FEL commissioning results are presented and the current status of the first and second FELs as well as their future development prospects are described.

The Novosibirsk FEL facility has three FELs, installed on the first, second and fourth orbits of the ERL. The first FEL covers the wavelength range of 90 - 240 mkm at an average radiation power of up to 0.5 kW with a pulse repetition rate of 5.6 or 11.2 MHz and a peak power of up to 1 MW. The second FEL operates in the range of 40 - 80 mkm at an average radiation power of up to 0.5 kW with a pulse repetition rate of 7.5 MHz and a peak power of about 1 MW. These two FELs are the world's most powerful (in terms of average power) sources of coherent narrow-band (less than 1%) radiation in their wavelength ranges. The third FEL was commissioned in 2015 to cover the wavelength range of 5 - 20 mkm. The Novosibirsk ERL is the first and the only multiturn ERL in the world. Its peculiar features include the normal-conductive 180 MHz accelerating system, the DC electron gun with the grid thermionic cathode, three operation modes of the magnetic system, and a rather compact (6×40 m2) design. The facility has been operating for users of terahertz radiation since 2004.

Novosibirsk FEL facility is based on the first in the world multi-turn energy recovery linac (ERL). It comprises three FELs (stages). FELs on the first and the second tracks were commissioned in 2004 and 2009 respectively and operate for users now. The third stage FEL is installed on the fourth track of the ERL. It includes three undulator sections and 40-meters-long optical cavity. The design tuning range of this FEL is from 5 to 20 microns and the design average power at bunch repetition rate 3.74 MHz is about 1 kW. Recent results of the third stage FEL commissioning are reported.

Novosibirsk free electron laser (FEL) facility contains three FELs operating in the wavelength range 8-240 micron at average power up to 0.5 kW and peak power about 1 MW. Radiation users works at 6 user stations performing biological, chemical, physical and medical research.

The high-power free electron laser (FEL) facility NovoFEL has been created at Budker INP. Its wavelength can be tuned over a wide range in terahertz and infrared spectrum regions. This FEL uses a multi-turn energy recovery linac with five straight sections as a source of electron beam. Three sections are used for three FELs which operate in different wavelength ranges (the first at 90-240 mu m; the second at 37-80 mu m; the third at 5-20 mu m).The first and second FELs were commissioned in 2003 and 2009, respectively. They operate for users now. The third FEL is installed on the fourth accelerator track, which is the last one; the electron energy is maximal here. This FEL comprises three undulator sections and a 40-m optical cavity. The first lasing of this FEL was obtained in the summer of 2015. The radiation wavelength was 9 mu m and the average power was about 100 W. Radiation of the third FEL was delivered to the user stations, and the first user shifts were performed recently. The results of the commissioning of the third FEL, the current status of the first and second FELs and future development prospects are presented. (C) 2016 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

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.

CW 100 keV electron RF gun for 40 mA average beam current was developed, built, and commissioned at BINP SB RAS. The RF gun consists of normal conducting 100 MHz RF cavity with a gridded thermo cathode unit, CW 16 kW generator with GU-92A tetrode in the output stage, and a set of LLRF electronics. The gun was tested up to the design specifications at a test bench that includes a diagnostics beam line. The design features of different components of the gun are presented. Preparation and commissioning experience is discussed. The beam test results are summarized. INTRODUCKTION A 100 MHz RF electron injector was designed and manufactured at BINP for continuous wave (CW) powerful accelerator in RFNC-VNIIEF [1]. This compact accelerator, similar to the type of «RHODOTRON» [2], is designed for continuous production of short electron bunches with energy of 1.5 ÷ 7.5 MeV with power of 300 kW and higher. Each bunch passes through a single accelerating cavity of the accelerator several times. After each pass, the beam is turned in the bending magnets. In order to preserve the transverse dimensions of the electron bunches within the aperture after passing through the bends, the bunches should have small enough energy spread (<1%) and be quite short (<0.2 ns). An advantage of RF guns compared with static guns is the absence of cathode back bombardment with accelerated ions of residual gas ionized by an electron beam. This allows having a long lifetime of the cathodes and operating the gun continuously in the vacuum of 10 -6 ÷ 10 -7 Torr. Also, this enables raising the gun voltage and thus increasing the energy of the electron beam from 3040 keV to 100 keV proportionally to the beam current to the power of 2/3, in-accordance with the Poisson law. Furthermore, calculations showed that the increased voltage in the RF injector in combination with the effect of the longitudinal beam bunching therein provides a reduction in the energy spread of up to 0.3% (rms) in the first passage of the accelerator and the bunch shortening by up to 18 times.

The Novosibirsk terahertz FEL facility is based on the normal conducting CW energy recovery linac (ERL) with rather complicated lattice. This is the only multiorbit ERL in the world. It can operate in three different modes providing electron beam for three different FELs. The first FEL works for users since 2003. This FEL radiation is used by several groups of scientists which include biologists, chemists and physicists. Its maximum average and peak powers are 500 W and 1MW and wavelength can be tuned from 110 up to 240 microns. The high peak and average powers are used in experiments on material ablation and biological objects modification. The second FEL is installed on the second orbit. The first lasing of this FEL was achieved in 2009. Its radiation has almost the same average and peak powers and is delivered to the same user stations as the first FEL one, but its tunability range lies between 35 and 80 microns. The third FEL will be installed on the fourth orbit. In this paper we report the latest results obtained from the operating FELs as well as our progress with the commissioning of the two remaining ERL orbits. We also discuss possible options for the future upgrade.

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.

An ultrafast electron diffraction setup is described and requirements for a signal source are determined. Taking into account these requirements, a low-noise microwave signal source with a 6.2-GHz-frequency and ≥6-W power, and 6.1-GHz additional frequency and ≥5-mW power is designed. The phase noise level at the output frequency was no higher than −115 dB/Hz when the offset from the carrier was 10 kHz. The manufactured setup was supplied to the Max-Planck Institute (Garching, Germany), experiments were performed, and the first results were obtained.