Experimental Investigations on Effects of Operation Parameters on a 263-GHz Gyrotron

In this article, the experimental investigations on a 263-GHz gyrotron are presented. With the change of the operating magnetic field and the beam energy, the operating frequency is adjusted and the output power is also varied. It is found that when the operating magnetic field changes from 9.59 to 9.82 T at a fixed operating voltage of 20 kV and a beam current of 0.8 A, the operating frequency increases from 263.39 to 264.84 GHz, the frequency-tuning range is about 1.45 GHz, and the output power is from 26 to 463 W. When the operating voltage increases from 14.4 to 22.2 kV at a fixed operating magnetic field of 9.65 T, the operating frequency decreases from 263.68 to 263.40 GHz, the frequency-tuning range is 0.28 GHz, and the output power changes from 52 to 424 W. When the operating magnetic field is fixed at 9.65 T and the operating voltage is fixed at 20 kV, but the beam current increases from 120 to 880 mA, the output power increases from 21 to 277 W, the operating frequency increases from 263.396 to 263.425 GHz, and the frequency-tunable range is 0.029 GHz. The effects of the axial position of the gyrotron in the superconducting magnet system on the operating frequency, the frequency-tuning range, and the output power are also investigated experimentally. When the beam current is increased, the nonstationary phenomenon is observed.

[1]  Wei Wang,et al.  Detailed Investigation on Nonstationary Behavior in a Frequency-Tunable Gyrotron , 2022, IEEE Transactions on Electron Devices.

[2]  Zhenhua Wu,et al.  Experimental Investigations on a 500GHz Continuously Frequency-Tunable Gyrotron , 2021, IEEE Electron Device Letters.

[3]  R. Zhong,et al.  Theoretical Investigations on Forward-Wave and Backward-Wave Operation of a Frequency-Tunable Gyrotron , 2020, IEEE Transactions on Electron Devices.

[4]  R. Griffin,et al.  Second Harmonic 527-GHz Gyrotron for DNP-NMR: Design and Experimental Results , 2020, IEEE Transactions on Electron Devices.

[5]  M. Thumm,et al.  High-power gyrotrons for electron cyclotron heating and current drive , 2019, Nuclear Fusion.

[6]  Shota Yamazaki,et al.  Actin polymerization is activated by terahertz irradiation , 2018, Scientific Reports.

[7]  G. Denisov,et al.  High-power sub-terahertz source with a record frequency stability at up to 1 Hz , 2018, Scientific Reports.

[8]  M. Tani,et al.  Strong yellow emission of high-conductivity bulk ZnO single crystals irradiated with high-power gyrotron beam , 2017 .

[9]  V. Bratman,et al.  Numerical Study of a Low-Voltage Gyrotron (“Gyrotrino”) for DNP/NMR Spectroscopy , 2017, IEEE Transactions on Plasma Science.

[10]  T. H. Chang,et al.  Possibilities for Continuous Frequency Tuning in Terahertz Gyrotrons with Nontunable Electrodynamic Systems , 2016 .

[11]  T. Fujiwara,et al.  Advanced instrumentation for DNP-enhanced MAS NMR for higher magnetic fields and lower temperatures. , 2016, Journal of magnetic resonance.

[12]  A. Tsvetkov,et al.  Experimental investigations of 263 GHz/1 kW gyrotron based system for diagnostic of various media , 2015, 2015 IEEE International Conference on Plasma Sciences (ICOPS).

[13]  S. Asai,et al.  First Millimeter-wave Spectroscopy of the Ground-state Positronium , 2014, 1403.0312.

[14]  I. Sudiana,et al.  Densification of Alumina Ceramics Sintered by Using Submillimeter Wave Gyrotron , 2013 .

[15]  F. Legrand,et al.  Manufacturing of a 263 GHz continuously tunable gyrotron , 2013, 2013 IEEE 14th International Vacuum Electronics Conference (IVEC).

[16]  R. Griffin,et al.  Continuously Tunable 250 GHz Gyrotron with a Double Disk Window for DNP-NMR Spectroscopy , 2012, Journal of infrared, millimeter and terahertz waves.

[17]  M. Shapiro,et al.  Spectroscopic temperature measurements of air breakdown plasma using a 110 GHz megawatt gyrotron beam , 2012 .

[18]  A. Torrezan,et al.  Operation of a Continuously Frequency-Tunable Second-Harmonic CW 330-GHz Gyrotron for Dynamic Nuclear Polarization , 2011, IEEE Transactions on Electron Devices.

[19]  R. Griffin,et al.  Solid-state dynamic nuclear polarization at 263 GHz: spectrometer design and experimental results. , 2010, Physical chemistry chemical physics : PCCP.

[20]  T. Idehara,et al.  Continuously Frequency Tunable High Power Sub-THz Radiation Source—Gyrotron FU CW VI for 600 MHz DNP-NMR Spectroscopy , 2010 .

[21]  K. Felch,et al.  Demonstration of a 263 GHz gyrotron for Dynamic Nuclear Polarization , 2009, 2009 IEEE International Conference on Plasma Science - Abstracts.

[22]  Yoshiteru Hidaka,et al.  Observation of large arrays of plasma filaments in air breakdown by 1.5-MW 110-GHz gyrotron pulses. , 2008, Physical review letters.

[23]  M. Thumm,et al.  A 250 GHz, 50 W, CW Second Harmonic Gyrotron , 2007 .

[24]  I. Ogawa,et al.  Detailed Consideration of Experimental Results of Gyrotron FU CW II Developed as a Radiation Source for DNP-NMR Spectroscopy , 2007 .

[25]  R. Griffin,et al.  Second harmonic operation at 460 GHz and broadband continuous frequency tuning of a gyrotron oscillator , 2005, IEEE Transactions on Electron Devices.

[26]  K. R. Chu,et al.  The electron cyclotron maser , 2004 .

[27]  C. Fan,et al.  Linear and time-dependent behavior of the gyrotron backward-wave oscillator. , 2002, Physical review letters.

[28]  P. Siegel.  Terahertz Technology , 2001 .

[29]  Aripin,et al.  High Power, Frequency Tunable, Submillimeter Wave ESR Device Using a Gyrotron as a Radiation Source , 2000 .