Pulsed Orotron—A new microwave source for submillimeter pulse high-field electron paramagnetic resonance spectroscopy
2004; American Institute of Physics; Volume: 75; Issue: 9 Linguagem: Inglês
10.1063/1.1778071
ISSN1527-2400
AutoresYu. A. Grishin, Martin R. Fuchs, Alexander Schnegg, А. А. Дубинский, Б. С. Думеш, F. S. Rusin, V. L. Bratman, K. Möbius,
Tópico(s)Atomic and Subatomic Physics Research
ResumoA vacuum-tube device for the generation of pulsed microwave radiation in the submillimeter range (up to 380 GHz) is presented, designed for use as a source in a 360 GHz high-field/high-frequency electron paramagnetic resonance (EPR) spectrometer—the pulsed Orotron. Analogous to the known continuous wave (cw) version, in the pulsed Orotron microwave radiation is generated by the interaction of a nonrelativistic electron beam with a diffraction grating (stimulated Smith–Purcell radiation) in feedback with an open Fabry–Pérot resonator construction. The presented design extends the cw Orotron by a gate electrode and a high-voltage pulsing unit to control the electron beam current. The generated pulses at 360 GHz have pulse lengths from 100 ns–10 μs and a pulse power of (22±5) mW. The output in a broader frequency band between 320 and 380 GHz ranges from 20 up to 60 mW. Within a 10 μs time slot, incoherent pulse trains of arbitrary duration can be generated. The pulsed Orotron has been incorporated in the quasioptical microwave bridge of a heterodyne induction mode EPR spectrometer. The first free induction decay measurements at a microwave frequency of 360 GHz and a magnetic field of 12.8 T on a polycrystalline perylenyl–ion sample are presented and future applications and extensions of Orotron-EPR spectroscopy are discussed.
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