Title :
Design and experimental results from a 527 GHz gyrotron for DNP-NMR spectroscopy
Author :
Jawla, Sudheer K. ; Guss, William C. ; Shapiro, Michael A. ; Temkin, Richard J.
Author_Institution :
Plasma Sci. & Fusion Center, Massachusetts Inst. of Technol., Cambridge, MA, USA
Abstract :
A 527 GHz gyrotron has been designed and built for an 800 MHz DNP-NMR spectrometer. The gyrotron is designed at the second harmonic (ω=2 ωc) of the electron cyclotron frequency to produce 20 W continuous microwave power at 527 GHz frequency using a diode type electron gun (Vk ~ 13.0 kV, Ib=150 mA). An internal dimpled wall helical cut launcher is designed along with two mirrors and an internal periscope assembly to convert the operating mode in to a fundamental mode, HE11, of a corrugated waveguide with mode content of ~ 93%.
Keywords :
NMR spectroscopy; UHF tubes; assembling; diodes; dynamic nuclear polarisation; electron guns; gyrotrons; mirrors; submillimetre wave tubes; waveguides; DNP-NMR spectrometer; DNP-NMR spectroscopy; HE11 mode; corrugated waveguide; current 150 mA; diode type electron gun; dynamic nuclear polarization; electron cyclotron frequency; frequency 527 GHz; frequency 800 MHz; gyrotron; internal dimpled wall helical cut launcher; internal periscope assembly; mirror; power 20 W; Assembly; Gyrotrons; Harmonic analysis; Magnetic fields; Polarization; Spectroscopy; Superconducting magnets;
Conference_Titel :
Infrared, Millimeter, and Terahertz waves (IRMMW-THz), 2014 39th International Conference on
Conference_Location :
Tucson, AZ
DOI :
10.1109/IRMMW-THz.2014.6956164
