Bruker E580 – A shared X-/Q-band EPR Spectrometer

The Bruker ELEXSYS-E580 EPR Spectrometer is a shared instrument funded by the NIH Shared Instrumentation Grant 1S10OD032355 (PI Smirnov). In October 2025, the instrument was relocated from Room 3 of Cox Hall to Room 2110 Broughton Hall.

Accessing the Instrument

For accessing the instrument, training, and scheduling EPR experiments, please contact either

Alex I. Smirnov (PI), aismirno(at)ncsu.edu, 919-513-4377
Sergey Milikisiyants (Research Scholar), smiliki(at)ncsu.edu
or send email to pulse_epr_spectrometer(at)ncsu.edu

Acknowledgement of the NIH Support

All users of the Bruker ELEXSYS-E580 EPR Spectrometer are asked to acknowledge NIH support in their publications and presentations.

Sample acknowledgements:

EPR data were acquired on an instrument funded by the NIH award RR023614 and S10OD032355 at the NCSU Shared EPR Laboratory.

When combining with other grants:

Research reported in this publication was supported in part by the National Institutes of Health under award numbers [insert numbers] and the Shared Instrumentation Grants RR023614 and S10OD032355, which funded the E580 spectrometer in the NCSU Shared EPR Laboratory.

When using X-band Continuous Wave EPR spectrometer acknowledge the following grants:

Research reported in this publication was supported in part by the National Institutes of Health under award numbers [insert numbers] and Instrumentation Grants from the National Science
Foundation (no. CHE-0840501), and NCBC (no. 2009 IDG-1015).RR023614 and S10OD032355, which funded the E500 spectrometer in the NCSU Shared EPR Laboratory.

Cost of Operating E580

The user are responsible for EPR (e.g., tubes) and other consumables (e.g., compressed gasses and liquid nitrogen for a cold trap when operating cryogen-free VT)
To recover the cost of servicing the cryogen-free VT the users are charged $1.0/h.
Routine maintenance cost of the spectrometer is shared between the users proportionally their annual usage. The current total maintenance costs for year 2025 and 2026 is not to exceed $6,000 annually.

Brief Description of the Instrument

ELEXSYS-E580 is a versatile FT/CW EPR spectrometer system designed for both continuous wave (CW) and pulse electron paramagnetic resonance (EPR) experiments, with capabilities at X-band (around 9.4 GHz) and Q-band (around 34 GHz) frequencies. After completing the most recent upgrade in 2025, the instrument is configured with two state-of-the-art high-power pulse microwave amplifiers (1 kW for X-band and 300 W for Q-band), an AWGII pulse shaping system for flexible and precise control of pulse sequences, and a cryogen-free variable temperature accessory that enables experiments over a wide temperature range without the need for traditional liquid cryogens.

Instrument Features

Dual-mode operation: Supports both CW and pulsed (FT) EPR, allowing for standard and advanced time-domain measurements.
Multi-frequency capabilities: Runs X-band and Q-band experiments.
Pulse shaping: The AWGII pulse system enables state-of-the-art pulse modulation and phase cycling, vital for advanced EPR methodologies.
High-power pulse amplifiers: Allows for demanding pulsed experiments such as DEER, ESEEM, and pulse ENDOR.
Variable temperature control: The cryogen-free system provides precise sample temperature regulation, enhancing stability and reducing operational costs.

Experimental Capabilities

The ELEXSYS-E580 supports a diverse set of EPR experiments:

CW EPR Spectroscopy: Traditional continuous wave methods used for characterizing the electronic environment of paramagnetic centers.
Pulse EPR (FT-EPR): Includes advanced techniques such as spin echo, electron spin echo envelope modulation (ESEEM) and time-resolved EPR.
Pulse ENDOR (Electron Nuclear Double Resonance): Enables enhanced resolution and investigation of hyperfine interactions, often used in biological and material science studies.
Pulse ELDOR and DEER (Double Electron-Electron Resonance): Allows gor measurement of long-range spin-spin distances, critical for studying biomolecular structure and dynamics.
2D EPR including HYSCORE and Multi-frequency Experiments: The instrument platform allows for multi-pulse protocols and the separation of interaction effects in two dimensions, broadening analytical possibilities.
Variable temperature EPR: Facilitates research into temperature-dependent magnetic properties, relevant in materials science and photophysics.

Applications

Study of paramagnetic centers (radicals, transition metal ions) in solid and liquid samples.
Measurements of spin-lattice (T1) and spin-spin (T2) relaxation times.
Determination of structure in bio-macromolecules (e.g., proteins, nucleic acids) and materials using pulse EPR distance measurements.
Investigation of hyperfine structure and local environments using HYSCORE, ENDOR and ESEEM.

In summary, the Bruker ELEXSYS-E580 offers state-of-the-art capabilities for both standard and cutting-edge EPR spectroscopy across a broad range of sample types and experimental needs, making it ideal for research in chemistry, materials science, biochemistry, and physics including quantum sensing and information science.