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In this paper, the design of a magnetron injection gun (MIG) with a single-anode built for W-band gyrotron oscillator is presented. The simulation of the MIG is finished with the help of a trajectory program EGUN. The simulation results indicate that the velocity ratio with velocity spread of less than 4% is 1.41.
During last years several new gyrotrons were developed at IAP/GYCOM. Main efforts were spent for development 170GHz/1MW/50%/CW gyrotron for ITER and multi-frequency gyrotrons. The main ITER requirements to a gyrotron have been demonstrated: 1MW power, 1000 seconds pulse duration, 53% efficiency. The gyrotron operation regime of 1.2 MW was found for 100 second pulses. For a multi-frequency gyrotron...
Calabazas Creek Research, Inc. is developing a system for coupling radiation out of gyrotrons that eliminates the external matching optical unit and is broadband. A critical component is a Brewster window in HE11 waveguide. This paper describes the design and thermal-mechanical modeling of the window.
The design work for 95 GHz, 100 kW gyrotron for Active Denial System (ADS) application is presented. The mode selection is performed considering the various technical constraints. Particle-in-Cell code is used for the beam-wave interaction computation and cavity design. In addition, the designs of electron beam source, collector and RF window are also discussed. The design results confirm the RF power...
A gyrotron operating at the second cyclotron harmonic in a magnetic field of 9.7 T has produced a CW output power of 25 W at 527 GHz. The gyrotron is now being employed in Dynamic Nuclear Polarization (DNP) Applications. The gyrotron design and results of the tests are presented.
Theoretical calculation, numerical simulation and experimental development of a W-band gyro-TWA with a helically corrugated waveguide and a cusp electron gun are presented. The cusp gun generated a 40 keV, 1.5 A axis-encircling electron beam. The maximum output of the gyro-TWA was predicted to be 5 kW with a 3 dB frequency bandwidth of 90–100 GHz and a saturated gain of 37 dB. The latest experimental...
ITER is an international project supported by seven partners: China, Europe, India, Japan, Korea, Russian Federation and USA. Formally established in 2006, construction has started in France, more precisely in Provence. General progress of the project is presented followed by a focus on the RF systems which will provide 40 MW into the plasma, based on systems around 50 MHz and 170 GHz. These systems...
A high-order-mode harmonic multiplying gyro-TWA could allow the amplifier to achieve high average powers. An improved mode-selective circuit is employed for suppressing non-TE0n competing modes while wall losses are employed for suppressing TE0n competing modes. A G-band second harmonic multiplying gyro-TWT is predicted to yield a peak output power of 56 kW at 200 GHz with an efficiency of 11%, a...
Having the capability of generating superior output power with good spatial pattern at sub-THz region compared to other sources, gyrotron is well suited for realtime T-ray imaging application. In this presentation, details of the compact gyrotrons developed at KERI for real-time inspection of foreign bodies in food will be discussed.
A sealed off magnetron injection gun (MIG) collector module for 42 GHz 200 kW gyrotron has been developed. The paper reports the high voltage and beam-emission test result. In addition, the current-voltage characteristics at different heater wattage are also discussed from recent tests.
In this paper, design of the interaction structure to generate 2THz radiation at second cyclotron harmonic is presented. Based on start oscillating current and stability at high magnetic field, TE24,4 is selected as operating mode. The eigen mode analysis and beam wave interaction in the interaction structure have been carried out using MAGIC and CST-Microwave Studio.
This paper presents a method for the design of phase correcting mirrors for gyrotrons. A computer code has been developed for vector analysis of electromagnetic fields in the mirror systems. Based on the Katsenelenbaum-Semenov method, the computer code has been written for the synthesis of adapted phase correcting mirrors. As an example, a quasi-optical mode converter including a Vlasov launcher and...
A nonlinear steady-state multimode theory is developed to investigate mode competition in gyro-TWT. Calculation shows that competition mode may be suppressed by a large driving power in a particular range.
The experimental study of a Q-band gyrotron-travelling-wave tube (gyro-TWT) amplifier operating in the circular TE01 mode at fundamental cyclotron harmonic is presented. A periodic dielectric loaded structure is adopted in the interaction circuit of the gyro-TWT to suppress spurious modes TE11 and TE21. A saturated peak power of 175 kW is obtained corresponding to saturated gain of 53 dB and an efficiency...
We apply an external circuit model to our simulations of (MIG) Magnetron Injection Guns to improve fidelity and encompass additional physics relating to the voltage and current delivery systems which, to date, have not been included in out models. These studies are primarily intended to look at (LFO) Low Frequency Oscillations, and so inclusion of the external circuit can represent external geometry...
A gyrotron amplifier that uses a novel photonic band gap (PBG) interaction circuit has achieved a peak small signal gain of 38 dB at 247.7 GHz, 32 kV and 0.35 A. The instantaneous −3 dB bandwidth of the amplifier at peak gain is 0.4 GHz. A peak output power of 45 W has been measured. The output power is not saturated but is limited by the 7.5 mW of available input power; the saturated output power...
EU is developing a 1 MW cylindrical cavity gyrotron. In the last year the design of the components of the new gyrotron has been finalized while the technological design of the new tube has been defined. In the present paper, the main characteristics of the new EU gyrotron for ITER are presented.
This paper reports on a diamond Brewster angle window which has been used as a vacuum barrier in a 140 GHz step-frequency tunable high power gyrotron. This configuration ensures operation of the gyrotron at different frequencies without reflection of the RF power and provides excellent material properties of CVD diamond in the mm wave range.
A 2M CW, RF load for gyrotrons was designed, built, and tested. A rotating launcher distributes the RF power along the loss surfaces. In addition to improving the heat dissipation, arcing caused by constructive interference is avoided. Several loads have been delivered, and the latest performance measurements will be presented.
Efforts are continuing to improve the quality of controlled porosity reservoir cathodes and measure performance. CPR cathodes are being incorporated into several new configurations, including a magnetron injection gun, 15-beam klystron, and a Pierce gun for a 50 MW X-Band klystron. Improved computational tools assist users in CPR cathode design.
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