Numerical Study of a Low-Voltage Gyrotron ("Gyrotrino") for DNP/NMR Spectroscopy

作者：Bratman V L^*; Fedotov A E; Kalynov Yu K; Makhalov P B; Osharin I V

来源：IEEE Transactions on Plasma Science, 2017, 45(4): 644-648.

DOI：10.1109/TPS.2017.2673550

• Collector
• dynamic nuclear polarization (DNP)
• gyrotron
• low voltage
• nuclear magnetic resonance (NMR) spectroscopy

Feasibility of a gyrotron for the dynamic nuclear polarization (DNP) purpose, integrated with nuclear magnetic resonance (NMR) spectrometer inside a single cryomagnet, is analyzed on the basis of numerical simulations. The necessary condition for DNP is matching of the gyrotrino and DNP frequencies. This imposes a strong restriction on the gyrotron operating voltage, which should be less than 2 kV. The most part of the uniform magnetic field region in the cryomagnet is occupied by a sample with NMR probe, so there is a very limited space for the gyrotron cavity. This dictates a number of peculiarities for the gyrotrino design, in particular, the diffraction power output from the cathode end of the cavity and collecting of a thin electron beam in a strong magnetic field. According to simulations, the gyrotrino operating at the fundamental cyclotron resonance with a voltage of 1.5 kV can provide an output power of 10-20 W at a frequency of 264 GHz, which is suitable for many NMR-DNP experiments.

• 出版日期2017-4