Transmission Line for DNP-NMR Driven by Terahertz Wave
The dynamic nuclear polarization enhanced nuclear magnetic resonance(DNP-NMR)spec-troscopy system driven by terahertz wave can greatly improve the signal sensitivity and shorten the detec-tion time.In the system,a transmission line is required to transmit terahertz wave between the driving source gyrotron and the spectrometer.A terahertz transmission line consisting of quasi-optical mode con-verter(QOMC)and corrugated waveguide for a 400MHz DNP-NMR system is designed and tested.The result shows that the QOMC can convert the 263GHz gyrotron TE03 mode into a quasi-Gaussian beam with a Gaussian component of 97%,and the final output beam of the entire transmission line has a Gaussi-an component of 96.3%.