University of Technology-IraqEngineering and Technology Journal1681-6900383B20201225Analysis and Design of 460 GHz Microwave Gyrotron Oscillator16116716952510.30684/etj.v38i3B.1937ENLuma Y.AbbasDepartment of Physics, College of Science University of Al-Mustansiriyah, Baghdad, IraqNedal A.HussainDepartment of Physics, College of Science University of Al-Mustansiriyah, Baghdad, IraqJournal Article20180612This paper is concerned with the analysis and design of a gyrotron oscillator with 460 GHz that can excite both modes (TE231) the fundamental (230GHz) and (TE061, TE261) second harmonic (near 460GHz). The oscillator is operated with 12KV beam voltage and 100mA beam current, and a computer program was developed to study the cavity in this oscillator and the wave-particle interaction inside it using the forward finite difference technique as a numerical method. The input data of the program are electron energy, velocity ratio, normalized cavity length, the normalized value of the external magnetic field, the mode number (m,n,l), and nth-non van shining root of J_m^' (x)=0 to calculate the beam and starting currents, frequency and quality factor of the cavity. The results show good agreement with other reported works [10]- [12]- [13]- [14], [15] .This oscillator can serve as a millimeter-wave source at the magnetic field of (16.4T) for enhanced nuclear magnetic resonance and can be used to perform the biological experiment.https://etj.uotechnology.edu.iq/article_169525_50aceeb1baa5117666f13d5b9b6b6dc9.pdf