Title :
527 GHz gyrotron for DNP-NMR spectroscopy
Author :
Jawla, Sudheer ; Shapiro, Michael ; Guss, William ; Temkin, Richard
Author_Institution :
Plasma Sci. & Fusion Center, Massachusetts Inst. of Technol., Cambridge, MA, USA
Abstract :
We describe the design of a 20W, continuous wave 527 GHz gyrotron for Dynamic Nuclear Polarization (DNP) enhanced solid state Nuclear Magnetic Resonance (NMR) spectroscopy on an 800 MHz spectrometer. A 9.8 T helium-free superconducting magnet with a warm bore diameter of 76mm is planned for the gyrotron operation. The gyrotron resonator cavity is designed to operate in the TE11,3,p mode at 527 GHz which is the second harmonic (ω=2ωc) of the electron cyclotron frequency. The design is based on a diode electron gun (Vk=15 kV, Ib=190 mA) and lateral output with an internal Vlasov-type mode converter. Frequency tunability of Δf/f ≈ 0.25% is being studied around the nominal frequency of 527 GHz, with a goal of constant output power of more than 20W.
Keywords :
NMR spectroscopy; cavity resonators; convertors; cyclotrons; dynamic nuclear polarisation; electron guns; gyrotrons; submillimetre wave tubes; superconducting magnets; DNP-NMR spectroscopy; TE11,3,p mode; continuous wave gyrotron; current 190 mA; diode electron gun; dynamic nuclear polarization enhanced solid state nuclear magnetic resonance spectroscopy; electron cyclotron frequency; frequency 527 GHz; frequency 800 MHz; gyrotron resonator cavity; helium-free superconducting magnet; internal Vlasov-type mode converter; magnetic flux density 9.8 T; power 20 W; size 76 mm; spectrometer; voltage 15 kV; Cavity resonators; Cyclotrons; Gyrotrons; Harmonic analysis; Magnetic fields; Nuclear magnetic resonance; Polarization; Dynamic Nuclear Polarization; Electron cyclotron frequency; Gyrotrons; Mode converter;
Conference_Titel :
Vacuum Electron Sources Conference (IVESC), 2012 IEEE Ninth International
Conference_Location :
Monterey, CA
Print_ISBN :
978-1-4673-0368-2
DOI :
10.1109/IVESC.2012.6264178
