O. V. Malygin

Technological gyrotrons with permanent magnet system

The fulfillment of the new project of creation of the industrial prototype of a technological gyrotron on permanent magnets are discussed. The permanent magnet system was designed, constructed and successfully tested for a gyrotron. A 30 GHz gyrotron (n=2) with rf-output power of 10 kW is under development with the TE/sub 12/ operating mode. An output power of 12 kW was obtained (efficiency 24%).

Development of the material processing system by using a 300 GHz gyrotron

An increase in the frequency of microwave used for the processing of materials has a great potential for the applications. We developed the material heating system by using a 300GHz gyrotron. This system are consisted of a 300 GHz, 3.5 kW, CW gyrotron with a cryogen free 12 T superconducting magnet, a corrugated circular waveguide and an applicator. The circular corrugated waveguide (i.d. = 6.35cm) with a corrugated period and depth of 254 /spl mu/m have been designed. The applicator have been designed both volumetric heating by uniformly distributed microwave and surface heating by a focused wave beam.

Development of 260 GHZ second harmonic CW gyrotron with high stability of output parameters for dnp spectroscopy

Development of continuous-wave 258.6 GHz gyrotron with output power about 20 W with high stability of output parameters is presented. This paper includes results of calculation, design, technical requirements and experimental tests for main subsystems of gyrotron and auxiliaries. The gyrotron setup shall be a part of a complex experimental system for NDP spectroscopy.Results of elaboration of continuous-wave 258.6 GHz gyrotron with output power about 100 W with high stability of output parameters is presented. This paper includes results of calculation, design, experiments and technical requirements for main subsystems of gyrotron and auxiliaries. The gyrotron setup is a main part of a complex experimental system for NDP spectroscopy.

Experimental investigation of technological gyrotrons

Powerful gyrotrons for technological applications, including material processing, are presented. 30 GHz gyrotrons at the second cyclotron harmonic TE/sub 02/ mode with oil-cooled solenoid were tested. On CW regime with output power 10 kW obtained efficiency 42% and output power 30 kW with efficiency 35%. The highest for the second harmonic gyrotrons efficiency 50% with 13 kW output power level was observed after modification of the tube. Experimental dependencies of output power and gyrotron efficiency before and after modification magnetic field profile are given. Conditions of high efficiency operation taking into account space-charge effects, velocity spread, RF field and static magnetic field profiles are discussed. Results of quality testing of cathodes and dependencies of the gyrotron efficiency on cathode emission inhomogeneity are presented.

Development of the 300 GHz/4 kW/CW gyrotron

The report presents results for design elaboration of 300 GHz/4 kW/CW gyrotron. The gyrotron is used with 12 T LiHe-free superconducting magnet. The possibilities to optimize an electron gun, mode converter and processes of mode interaction in the electron beam-cavity system are discussed for different versions of the 300 GHz gyrotron. The influence of ohmic load on the cavity, mode competition and other effects are also investigated.

Oscillation Characteristics of CW 300 GHz Gyrotron FU CWI

A CW 300 GHz gyrotron has been developed and installed in University of Fukui. A quasi-Gaussian beam is delivered through the vacuum window after mode conversion from the TE22.8 cavity mode with a complex of an internal radiator and beam shaping mirrors. Performance test has been carried out and the maximum CW output power of 1.75 kW has been attained at the beam voltage of 15 kV and the beam current of 1A. The maximum efficiency of 15.5% is obtained at the cathode voltage slightly lower than 15 kV.

Development of a large orbit gyrotron (LOG) operating at higher harmonics

Large orbit gyrotrons (LOGs) are being developed by use of a permanent magnet system. The operation test shows that the LOG radiates at high harmonic frequency up to fifth. Computer simulation results are compared with the experimental results.

Development of a large orbit gyrotron with a permanent magnet system

The development of a high harmonic gyrotron using a permanent magnet system is presented. On the basis of the design for a high harmonic gyrotron, using an encircling large-orbit electron beam and a permanent magnet system (large orbit gyrotron, LOG), a gyrotron tube has been constructed. The construction of a permanent magnet system has been also completed. The maximum field intensity is a little bit higher than 1 T. This work is being carried out as a collaboration with the Shin-etsu Kagaku Company, Institute of Applied Physics, Russian Academy of Science (IAP-RAS) and Institute of Electronics, and Bulgarian Academy of Science (IE-BAS). The gyrotron has already achieved 3rd, 4th and 5th harmonic operations with relatively high efficiency. Corresponding frequencies are 89 GHz, 113 GHz and 138 GHz, respectively. The output power at the 3rd harmonic operation was 2.5 kW and the efficiency 6.3%.

Preliminary Project of the 52 GHz/1 kW/CW Second Harmonic Gyrotron with Permanent Magnet

The report presents the 52 GHz/1 kW/CW second harmonic gyrotron preliminary design. The gyrotron will be used with appropriate 1 T permanent magnet of FIR Center FU. The possibilities to optimize an electron beam-cavity system are discussed for different gyrotron versions. The influence of cavity mode competition and other effects is investigated also.

Preliminary project of the 400 GHz/200 W/CW second harmonic gyrotron

The report presents the 400 GHz/0.2 kW/CW second harmonic gyrotron preliminary design. The gyrotron will be used with appropriate superconducting magnet. The possibilities to optimize an electron beam-cavity system and mode converter are discussed for different gyrotron versions. The influence of cavity mode competition and other effects are investigated.