| Literature DB >> 17431442 |
Colin D Joye1, Robert G Griffin, Melissa K Hornstein, Kan-Nian Hu, Kenneth E Kreischer, Melanie Rosay, Michael A Shapiro, Jagadishwar R Sirigiri, Richard J Temkin, Paul P Woskov.
Abstract
The operating characteristics of a 140-GHz 14-W long pulse gyrotron are presented. The device is being used in dynamic nuclear polarization enhanced nuclear magnetic resonance (DNP/NMR) spectroscopy experiments. The gyrotron yields 14 W peak power at 139.65 GHz from the TE(0,3) operating mode using a 12.3-kV 25-mA electron beam. Additionally, up to 12 W peak has been observed in the TE(2,3) mode at 136.90 GHz. A series of mode converters transform the TE(0,3) operating mode to the TE(1,1) mode. Experimental results are compared with nonlinear simulations and show reasonable agreement. The millimeter-wave output beam was imaged in a single shot using a pyroelectric camera. The mode patterns matched reasonably well to theory for both the TE(0,1) mode and the TE(1,1) mode. Repeatable mode patterns were obtained at intervals ranging from 0.8 s apart to 11 min apart at the output of the final mode converter.Entities:
Year: 2006 PMID： 17431442 PMCID： PMC1851936 DOI： 10.1109/TPS.2006.875776
Source DB: PubMed Journal: IEEE Trans Plasma Sci IEEE Nucl Plasma Sci Soc ISSN： 0093-3813 Impact factor: 1.222