Broadband Backward Wave Oscillator (BWO) Spectrometer

Using sub-THz and THz wave sources (BWOs), this transmission-type EPR/ESR spectrometer can be quasi-continuously frequency-tuned via applied voltage.

Typical experiments either benefit from its tunability, or from the relatively high power at the upper range of frequencies (above 600 GHz).

The sub-THz and THz wave sources used in the BWO-based spectrometer can also be used independently in EPR/ESR-type experiments. So far they have been successfully used in conjunction with the Keck 25-T resistive magnet, the SCMM 20-T superconducting magnet, and the EMR 15/17-T superconducting magnet. Given a proper probe, they can be employed with other magnets as well.

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  • Specs

  • Compatible Magnets

  • Compatible Techniques

  • Sample Types

  • Frequency: 70 GHz-1.2 THz
  • Field Strength: 25 tesla
  • Bore Diameter: 32 mm
  • Temperature: Depends on the cryostat used.
  • Crystal Rotation: None.
  • Pressure: Ambient
  • Sensitivity: Ca. 1012 spins/Gauss sec
  • Sample Size: 300 µL volume
  • Optical Excitation: None.

Given a proper probe, this instrument can be used with other magnets as well.

  • Frozen solutions
  • Powders & polycrystals
  • Single crystal (fixed orientation only)

Images & Sample Data

Click on images for details.

Related Publications

Stoll, S., et al, Hydrogen bonding of tryptophan radicals revealed by EPR at 700 GHz, J. Am. Chem. Soc. 2011, 133 Read online 

Krzystek, J., et al, High-frequency and -field EPR study of the Fe(H2O)62+ ion in ferrous fluorosilicate, J. Magn. Reson. 2011, 213 Read online 

Herchel, R., et al, Definitive determination of zero-field splitting and exchange interactions in a Ni(II) dimer: investigation of [Ni2(en)4Cl2]Cl2 using magnetization and tunable-frequency high-field EPR, J. Am. Chem. Soc. 2007, 129 Read online 

Zvyagin, S., et al, Elementary excitations in the spin-1 anisotropic Heisenberg antiferromagnetic chain system NiCl2-4SC(NH2)2, Phys. Rev. Lett. 2007, 98 Read online 

Krzystek, J., et al, Tunable-frequency high-field electron paramagnetic resonance, J. Magn. Reson. 2006 178 Read online 

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Last modified on 21 June 2021