Multi-Frequency CW-EPR

Multi-frequency EPR is the tool to disentangle magnetic field dependent from independent terms. Bruker BioSpin's EPR product range currently encompass two orders of magnitude in microwave frequencies: 

• L- and S-Band: 1 GHz and 3.5 GHz
• X-Band: most common frequency at ca. 9.8 GHz
• Q-Band : 34 GHz
• W-Band: at 94 GHz
• mm-wave: 263 GHz

While the advantages of high frequency EPR are obvious, low frequency EPR is the perfect choice for large samples and in particular in-vivo studies (ELEXSYS E540). 

Multi-frequency EPR spectra renders simulation much more effective. Also, motion effects can be studied over a wide temporal range.

Multi-frequency CW-EPR

The majority of CW-EPR systems operates at X-Band. Thus, the first step into multi-frequency CW-EPR is another operation frequency. In case of regular CW-EPR spectroscopy, Q-Band at 34 GHz is the best choice, because...

• Q-Band provides a threefold higher Zeemann energy
• Sample Size is still comparably large with 3 mm o.d.
• Q-Band probes with optional window or ENDOR capabilities are available

The following table provides a list of the most common EPR frequencies with their frequency range and g=2 field value for radical species, respectively (cf. also What is EPR? CW EPR Theory). All these frequencies are commonly offered by our selection of magnet systems.

Multi-frequency FT-EPR, ENDOR and ELDOR

Multi-frequency EPR by Bruker BioSpin is not limited to CW-EPR only. Bruker BioSpin's EPR products allow real multi-frequency and multi-resonance EPR, ENDOR and ELDOR both in CW- and Pulsed mode. For instance, thanks to the Intermediate Frequency (IF-) concept, an X-Band E580 system can readily be upgraded to Q-Band (SuperQ-FT).