Tunable Q-band resonator for low temperature electron paramagnetic resonance/electron nuclear double resonance measurements

Abstract

Articles you may be interested inSimultaneous measurements of heat capacity and spinlattice relaxation time in high magnetic field at low temperature Rev.Soundpressure response measurement in small rooms over a finite region A surface acoustic wave oscillatorbased modulator/mixer for frequencymodulated electron nuclear double resonance spectroscopy Rev.We present a tunable Q-band cavity for performing electron paramagnetic resonance and electron nuclear double resonance experiments at cryogenic temperatures. The resonator is a TE 011 brass cavity with radio frequency and magnetic field modulation ͑100 kHz͒ posts inside the microwave resonator. These posts are located close to the central sample position and thereby enhance the effective modulation and radio frequency fields. The crucial novel design aspect is the provision for continuously tuning the cavity resonant frequency, even under pumped liquid helium conditions over a broad frequency range ͑Ͼ2.0 GHz͒. Such a range will compensate for cooling-induced cavity contraction, presence of cryogenic in the cavity, and insertion of high dielectric frozen aqueous samples. The tuning range is indispensable for use with present commercial Q-band bridges whose low noise Gunn diode oscillators provide a small ϳ50 MHz tuning range.

Unraveling the Electronic Properties of the Photoinduced States of the H‐Cluster in the [FeFe] Hydrogenase from D. desulfuricans

“…All Q-band HYSCORE and pulse ENDOR measurements were performed on a Bruker Elexsys E 580 Q-band spectrometer equipped with the SuperQ-FT microwave bridge and an Oxford CF935 flow cryostat at temperatures ranging from 10-20 K. For these measurements, we used a slightly overcoupled cylindrical TE 011 homebuilt resonator with a construction similar to that described by Sienkiewicz et al [17,32] For pulse ENDOR experiments with the random-acquisition procedure, we used a homebuilt data acquisition system based on the SpecMan software [33] on an industrial PC workstation. The Bruker spectrometer was used for generating MW pulses and triggering the SpecMan system, which in turn controlled the generation of RF pulses and recorded the signal coming from the Bruker spectrometer.…”

The primary and secondary acceptors in bacterial photosynthesis III. Characterization of the quinone radicals Q A − ⋅ and Q B − ⋅ by EPR and ENDOR

“…Recent modifications, in particular the incorporation of a dielectric ring ENDOR resonator, are given in [31]. Experiments at 35 GHz were performed using an ENDOR cavity similar to that described in [32]. X-band EPR/ENDOR experiments at Technische Universität Berlin were carried out on a Bruker ESP 300E instrument with homebuilt ENDOR accessories described in [33,34].…”

Spin distribution of the H-cluster in the Hox–CO state of the [FeFe] hydrogenase from Desulfovibrio desulfuricans: HYSCORE and ENDOR study of 14N and 13C nuclear interactions

“…All Q-band HYSCORE and pulse ENDOR measurements were performed using a Bruker Elexsys E 580 Qband spectrometer equipped with a SuperQ-FT microwave bridge and an Oxford Instruments CF935 flow cryostat at temperatures ranging from 10 to 20 K. For these measurements we used a slightly overcoupled cylindrical TE 011 homebuilt resonator with a construction similar to that described by Sienkiewicz et al [30,41].…”