Pulsed Orotron - A new microwave source for submillimeter pulse high-field electron paramagnetic resonance spectroscopy

Journal Article · Wed Sep 01 00:00:00 EDT 2004 · Review of Scientific Instruments

DOI:https://doi.org/10.1063/1.1778071· OSTI ID:20643968

Grishin, Yu A; Fuchs, M R; Schnegg, A; Dubinskii, A A; Dumesh, B S; Rusin, F S; Bratman, V L; Moebius, K ^[1]

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1. Institute of Chemical Kinetics and Combustion, 630090 Novosibirsk (Russian Federation)

A 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-Perot 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 {mu}s 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 {mu}s 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.

• OSTI ID: 20643968
• Journal Information: Review of Scientific Instruments, Vol. 75, Issue 9; Other Information: DOI: 10.1063/1.1778071; (c) 2004 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0034-6748
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
DIFFRACTION GRATINGS
ELECTRIC POTENTIAL
ELECTRON BEAMS
ELECTRON SPECTROSCOPY
ELECTRON SPIN RESONANCE
EPR SPECTROMETERS
FREE ELECTRON LASERS
GHZ RANGE 100-1000
MAGNETIC FIELDS
MICROWAVE RADIATION
POLYCRYSTALS
PULSES
RESONATORS
SCANNING ELECTRON MICROSCOPY