V.K. Ovchar

Ultra-fast terahertz Schottky diode detector

An ultra-fast terahertz Schottky diode detector with a response time less than 20 ps is presented in the paper. The detector allowed us to measure not only the duration of the light pulses in the Novosibirsk terahertz free electron laser (NovoFEL) but also the time structure of these pulses in unstable regimes. This is important for determining the NovoFEL impulse power and for studying and suppressing its different instabilities.

Status of the Novosibirsk high power free electron laser

The first stage of Novosibirsk high power free electron laser (FEL) was commissioned in 2003. It is based on normal conducting CW energy recovery linac. Now the FEL provides electromagnetic radiation in the wavelength range 120-180 micron. The average power is 100 W. The measured linewidth is 0.3%, which is close to the Fourier-transform limit. The assembly of user beamline is in progress. Plans of future developments are discussed.

Novosibirsk terahertz free electron laser: status and survey of experimental results

During the past year, generation characteristics of the Novisibirsk terahertz free electron laser were growing up. It generates now coherent radiation tunable in the range 120-170 /spl mu/m at the repetition rate of 2.8-11.2 MHz. Maximum average output power reaches 400 W at 11.2 MHz. Laser radiations are transmitted through a 14-m optical beamline to the user stations. Experiments on chemistry, biology, spectroscopy, imaging and holography with employment of terahertz radiation are in progress.

High power THz applications on the NovoFEL

High power THz applications on the Novosibirsk terahertz free electron laser are described.

Highly sensitive fast Schottky-diode detectors in experiments on Novosibirsk free electron laser

Fast Schottky-diode detectors is used for measurement and optimization of main parameters of Novosibirsk free electron laser (FEL) such as losses in optical resonator, small signal gain, optimal output coupling. Possibility of applying of the device for measurement of coherence time and FEL pulse duration is considered. We plan also to calibrate free electron laser wavelengths by this detector and etalon universal gas laser. High sensitivity of the detector allows apply of it in various users experiments too.

Commissioning of the accelerator-recuperator for the FEL at the Siberian Center for Photochemical Research.

A 100 MeV eight-turn accelerator-recuperator intended to drive a high-power infrared free-electron laser (FEL) is currently under construction in Novosibirsk. The first stage of the machine includes a one-turn accelerator-recuperator that contains a full-scale RF system. It was commissioned successfully in June 2002.

A project of accelerator-recuperator for Novosibirsk high-power FEL

The first stage of the Novosibirsk high-power free-electron laser (FEL) was commissioned in 2003. It is driven by a CW energy recovery linac. The next step will be the full-scale machine, a four-track accelerator-recuperator based on the same RF accelerating structure. This upgrade will permit to get shorter wavelengths in the infrared region and increase the average power of the FEL by several times. The scheme and some technical details of the project are set out. The installation will be a prototype for future multiturn accelerator-recuperators.

Status of the free electron laser for the Siberian centre for photochemical research

Abstract A high-power infrared free electron laser is under construction in Novosibirsk. As the full-scale machine seems to be complicated and quite expensive, the project was divided into two stages so that the first-stage machine can be assembled and commissioned as soon as possible. Main features of the project and the current status are described.

CW 100 mA Electron RF Gun for Novosibirsk ERL FEL

Measured rf gun characteristics Average beam current, mA ≤100 Cavity Frequency, MHz 90 Bunch energy, keV 100 ÷ 400 Bunch duration (FWHM), ns 0.06 ÷ 0.6 Bunch emittance, mm mrad 10 Bunch charge, nC 0.3 ÷ 1.12 Repetition frequency, MHz 0.01 ÷ 90 Dark Current Impurity, mkA 0 Radiation Dose Power, mR/h 100/2m Operating pressure , Torr ~10-9-10-7 Cavity rf loses, kW 20 The most powerful in the world Novosibirsk CW FEL driven by ERL can be more powerful by an order of magnitude with this RF Gun

Novosibirsk Free Electron Laser: Terahertz and Infrared Coherent Radiation Source

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. As a source of electron bunches this FEL uses multi-turn energy recovery linac which has five straight sections. Three sections are used for three FELs which operate in different wavelength ranges (the first one 90-240 microns, the second 37-80 microns and the third 5-20 microns). The first and the second FELs were commissioned in 2003 and 2009 respectively. They operate for users now. The third FEL is installed on forth accelerator track which is the last one and electron energy is maximal here. It comprises three undulator sections and 40 m optical cavity. The first lasing of this FEL was obtained in summer, 2015. The radiation wavelength was 9 microns and average power was about 100 watts. The designed power is 1 kilowatt at repetition rate 3.75 MHz. Radiation of third FEL has been delivered to user stations recently. The third FEL commissioning results as well as current status of the first and second FELs and future development prospects are presented. OVERVIEW OF THE NOVOSIBIRSK FEL