Skip navigation
EPR Center Banner

EPR Center

250 MHz Spectrometer

 

E540 spectrometer   VHF magnet   Tomco amplifiers

 CW, rapid scan, and pulsed EPR data acquisition is based on the Bruker Elexsys E540 spectrometer system.

  A 4-coil air-core magnet for 90-G center field was locally design and constructed.  It is shown with z-gradient coils installed.   Pulsed RF amplifiers have been produced that have good fidelity for short pulses and turn off to within 10-20 dB of thermal noise level in ca. 80 ns after the pulse.

 

Cross loop resonator   dead time decrease with CLR   spectrum analyzer
The cross-loop resonator can be operated with a horizontal sample loop as in this version, which was designed for in vivo studies of mice.   Deadtimes as short as 200 ns have been achieved using the cross loop resonator and dynamic Q-spoiling.  

Vector network analyzers are used to measure the characteristics of resonators such as the cross loop resonators shown under construction, and completed.

 

Publications

 A Pulsed and Continuous Wave 250 MHz Electron Paramagnetic Resonance Spectrometer, R. W. Quine, G. A. Rinard, S. S. Eaton, G. R. Eaton, Magn. Reson. Engineer. 15, 59-91 (2002).

Frequency Dependence of EPR Signal Intensity, 248 MHz to 1.4 GHz, G. A. Rinard, R. W. Quine, S. S. Eaton, and G. R. Eaton, J. Magn. Reson. 154, 80-84 (2002).

250 MHz Crossed Loop Resonator for Pulsed Electron Paramagnetic Resonance, G. A. Rinard, R. W. Quine, G. R. Eaton, and S. S. Eaton, Magn. Reson. Engineer. 15, 37-46 (2002).

Adapting a Hall Probe Controller for Current Control of an Air-Core Magnet, G. A. Rinard, R. W. Quine, G. R. Eaton, and S. S. Eaton, Magn. Reson. Engineer. 15, 47-50 (2002).

Magnet and Gradient Coil System for Low-Field EPR Imaging, G. A. Rinard, R. W. Quine, S. S. Eaton, G. R. Eaton, E. D. Barth, C. A. Pelizzari, and H. J. Halpern, Magn. Reson. Engineer. 15, 51-58 (2002).

Frequency Dependence of EPR Signal Intensity, 250 MHz to 9.1 GHz, G. A. Rinard, R. W. Quine, S. S. Eaton, and G. R. Eaton, J. Magn. Reson. 156, 113-121 (2002).

Direct-detected rapid-scan EPR at 250 MHz, J. W. Stoner, D. Szymanski, S. S. Eaton, R. W. Quine, G. A. Rinard, and G. R. Eaton, J. Magn. Reson. 170, 127-135 (2004).

Frequency (250 MHz to 9.2 GHz) and Viscosity Dependence of Electron Spin Relaxation of Triarylmethyl Radicals at Room Temperature, R. Owenius, G. R. Eaton, and S. S. Eaton, J. Magn. Reson. 172, 168-175 (2005).

Rapid-Scan EPR with Triangular Scans and Fourier Deconvolution to Recover the Slow-Scan Spectrum, J. P. Joshi, J. R. Ballard, G. A. Rinard, R. W. Quine, S. S. Eaton, and G. R. Eaton, J. Magn. Reson. 175, 44-51 (2005).

Pulsed Saturation Recovery 250 MHz Electron Paramagnetic Resonance Spectrometer, R. W. Quine, S. S. Eaton, and G. R. Eaton, Conc. Magn. Reson. B, (Magn. Reson. Engin.) 26B, 23-27 (2005).

Electron Spin T2 of a Nitroxyl Radical at 250 MHz Measured by Rapid Scan EPR, M. Tseitlin, A. Dhami, R. W. Quine, G. A. Rinard, S. S. Eaton, and G. R. Eaton, Appl. Magn. Reson. 30, 651-656 (2006).

A Very Fast Switched Attenuator Circuit for Microwave and R.F. Applications, R. W. Quine, M. Tseytlin, S. S. Eaton, and G. R. Eaton, Conc. Magn. Reson. B, Magn. Reson. Engineer, 37B, 39-44 (2010).

Quantitative Rapid Scan EPR Spectroscopy at 258 MHz, R. W. Quine, G. A. Rinard, S. S. Eaton, and G. R. Eaton, J. Magn. Reson. 205, 23-27 (2010).

Use of the Frank Sequence in Pulse EPR, M. Tseitlin, R. W. Quine, S. S. Eaton,G. R. Eaton, H. J. Halpern, and J. H. Ardenkjaer-Larsen, J. Magn. Reson. 209, 306-309 (2011).

Rapid Frequency Scan EPR, M. Tseitlin, G. A. Rinard, R. W. Quine, S. S. Eaton, and G. R. Eaton, J. Magn. Reson. 211, 156-161 (2011).

Use of polyphase continuous excitation based on the Frank sequence for EPR and EPR Imaging, M. Tseitlin, R. W. Quine, S. S. Eaton, G. R. Eaton, J. Magn. Reson. 211, 221-227 (2011).

Digital EPR with an arbitrary waveform generator and direct detection at the carrier frequency, M. Tseitlin, R. W. Quine, G. A. Rinard, S. S. Eaton, and G. R. Eaton, J. Magn. Reson. 213, 119-125 (2011).

Frequency Dependence of Electron Spin Relaxation Times in Aqueous Solution for a Nitronyl Nitroxide Radical and Per-deuterated-Tempone between 250 MHz and 34 GHz, J. R. Biller, V. M. Meyer, H. Elajaili, G. M. Rosen, S. S. Eaton, and G. R. Eaton, J. Magn. Reson. 225, 52 – 57 (2012).