High-power 95 GHz pulsed electron spin resonance spectrometer
نویسندگان
چکیده
High-field/high-frequency electron spin resonance ~ESR! offers improved sensitivity and resolution compared to ESR at conventional fields and frequencies. However, most high-field/high-frequency ESR spectrometers suffer from limited mm-wave power, thereby requiring long mm-wave pulses. This precludes their use when relaxation times are short, e.g., in fluid samples. Low mm-wave power is also a major factor limiting the achievable spectral coverage and thereby the multiplex advantage of Fourier transform ESR ~FTESR! experiments. High-power pulses are needed to perform two-dimensional ~2D! FTESR experiments, which can unravel the dynamics of a spin system in great detail, making it an excellent tool for studying spin and molecular dynamics. We report on the design and implementation of a high-power, high-bandwidth, pulsed ESR spectrometer operating at 95 GHz. One of the principal design goals was the ability to investigate dynamic processes in aqueous samples at physiological temperatures with the intent to study biological systems. In initial experiments on aqueous samples at room temperature, we achieved 200 MHz spectral coverage at a sensitivity of 1.1310As spins and a dead time of less than 50 ns. 2D-electron-electron double resonance experiments on aqueous samples are discussed to demonstrate the practical application of such a spectrometer. © 2004 American Institute of Physics. @DOI: 10.1063/1.1710700#
منابع مشابه
A kilowatt pulsed 94 GHz electron paramagnetic resonance spectrometer with high concentration sensitivity, high instantaneous bandwidth, and low dead time.
We describe a quasioptical 94 GHz kW pulsed electron paramagnetic resonance spectrometer featuring pi/2 pulses as short as 5 ns and an instantaneous bandwidth of 1 GHz in nonresonant sample holders operating in induction mode and at low temperatures. Low power pulses can be as short as 200 ps and kilowatt pulses as short as 1.5 ns with timing resolution of a few hundred picoseconds. Phase and f...
متن کاملX-Band EPR Spectrometer with Customizable Arbitrary Waveform Generator based on a 1 GHz DAC Board
We present an EPR spectrometer featuring an arbitrary waveform generator (AWG) operating at 8–10 GHz (X-band) that is based on a 1 GHz digital-to-analog converter (DAC) boardwith a 42 dB (i.e. 14-bit) dynamic range. This AWG-capable spectrometer was developedto widen the scope of pulsed electron paramagnetic resonance (EPR) and enable new experiments. It generates shaped X-band pulses with prec...
متن کاملPulsed 180-GHz EPR/ENDOR/PELDOR spectroscopy.
Within this review, we describe a home-built pulsed electron paramagnetic resonance (EPR) spectrometer operating at 180 GHz as well as the incorporation of two double resonance techniques, electron nuclear double resonance (ENDOR) and pulsed electron double resonance (PELDOR), along with first applications. Hahn-echo decays on a TEMPO/polystyrene sample are presented, demonstrating that the obs...
متن کاملW-band PELDOR with 1 kW microwave power: molecular geometry, flexibility and exchange coupling.
A technique that is increasingly being used to determine the structure and conformational flexibility of biomacromolecules is Pulsed Electron-Electron Double Resonance (PELDOR or DEER), an Electron Paramagnetic Resonance (EPR) based technique. At X-band frequencies (9.5 GHz), PELDOR is capable of precisely measuring distances in the range of 1.5-8 nm between paramagnetic centres but the orienta...
متن کامل