Caltech Electron Paramagnetic Resonance (EPR) Facility

The Caltech EPR facility is equipped with two Bruker EPR spectrometers, an EMX X-band continuous-wave (CW) EPR spectrometer, and a newly acquired Bruker ELEXSYS E580 pulse EPR spectrometer capable of pulse and CW EPR spectroscopy at both X and Q-bands, as well as a variety of electron-electron double resonance (ELDOR) and electron-nuclear double resonance (ENDOR) spectroscopies. Groups or research laboratories interested in using instrumentation in the facility are welcome to visit the laboratory in the sub-basement of Crellin Hall (B264) or email Paul Oyala at phoyala@caltech.edu


 

 

Facility Instrumentation
 

EPR Sample Guide

 

Bruker ELEXSYS - E580 X,Q-band pulse EPR spectrometer

Scheduling sign-up

Bruker ELEXSYS - E580 X,Q-band pulse EPR spectrometer

 

Bruker EMX X-band CW-EPR Spectrometer

Scheduling sign-up

Bruker EMX X-band CW-EPR Spectrometer

 

Located in a renovated lab in the sub-basement of Crellin (B264), this instrument is a state-of-the-art Pulse and CW EPR spectrometer from Bruker capable of CW EPR, Pulse EPR, and ELDOR and ENDOR experiments at both X- and Q-Bands (9 GHz and 34 GHz, respectively). Additionally, it is equipped with an Arbitrary Waveform Generator (AWG) integrated into the pulse-forming unit which is capable of generating shaped pulses for advanced pulse EPR applications at either operating frequency.

  • Magnet
    • 10" Bruker EPR Magnet
  • Bridges
    • X-Band Pulse/CW E580 Bridge
      • SPFU Pulse Forming Unit
      • Spin Jet-AWG for ELDOR experiments (multiple MW frequency experiments) and generation of both frequency and amplitude shaped pulses. User-defined pulse shapes can be imported as well.
      • DICE ENDOR Unit
    • Q-Band SuperQ-FT Bridge
      • 10 W power upgrade for π/2 pulses of ≈ 10 ns.
  • Cavities/Resonators
    • X-Band
      • MS-5 Pulse EPR/CW EPR resonator (5 mm max sample diameter)
      • MD-4 Pulse EPR/ENDOR Dielectric Resonator (4 mm max sample diameter)
    • Q-Band
      • D-2 Pulse EPR/ENDOR Dielectric Resonator (1.8 mm max sample diameter)
  • Temperature Control
    • ColdEdge Variable temperature cryogen-free cryostat system
      • Capable of operation with stable sample temperatures as low as 5.4 K.
      • Uses a helium compressor and GM cryocooler to cool the sample space without the need for liquid helium or nitrogen as coolant.
      • Only consumes ~ 15 L of helium gas per thermal cycle for purging sample space.

Located in the basement of Crellin in B160, this instrument is an X-band CW EPR spectrometer capable of CW experiments from cryogenic temperatures to room temperature.

  • Magnet
    • 14" Bruker EPR Magnet
  • Bridges
    • X-Band CW Bridge
  • Cavities/Resonators
    • X-Band
      • High Sensitivity Cavity – 4119HS-W1
      • Cylindrical-mode resonator room temp EPR on aqueous or high-dielectric samples.
  • Temperature Control
    • Oxford ESR 900 liquid helium/nitrogen flow-through cryostat
    • Liquid nitrogen immersion dewar for experiments at fixed temperature at 77 K
    • Room temperature EPR – aqueous samples or high dielectric samples may be measured if small diameter capillary tube is used.

 

Contact Information

Paul Oyala, Ph.D.
Office: B250A Crellin
Labs: B264, B160 Crellin
Telephone – Office: (626) 395-4885; Lab: (626) 395-6055

 

Mailing Address:

Caltech
Chemistry 164-30
1200 East California Blvd.
Pasadena, CA 91125