The Queen Mary EPR Facility possesses a range of EPR resonators and cryostats for a variety of tasks.
The X-/Q-band facility can utilise a Bruker 4122SHQE for continuous wave EPR, an EN801 for cw ENDOR or an ER4116DM for parallel mode EPR when wishing to study the so called “forbidden” transitions. These resonators may be used in conjunction with the Oxford Instruments ESR900 or ESR910 continuous flow liquid Helium cryostats and ITC503 temperature controllers for accurate temperature control from 1.9-300K.
For pulsed operation, the facility possesses a Bruker EN4118X MD-5 flexline resonator and a EN4118X MD-4 flexline for pulsed ENDOR. Together with the ER5106 QT-E cw EPR and ENDOR Q-band resonator and 5107D2 Q-band pulsed EPR and ENDOR resonator these must be paired with the Oxford Instruments CF935O or CF935P 'bucket' cryostats. Temperatures ranging from 3.3-300K can be carried out on these resonators.
Currently, the X-/Q-band facility is in a state of flux during the installation of a closed-cycle cryostat for use with Flexline resonators. This will allow us to operate near-continuously without the limitations of liquid Helium supply, across a range of temperatures from 1.66K-300K.
The W-band facility can utilise either a pulsed EPR or a pulsed ENDOR TeraFlex resonator, dependent on experimental requirements, from 4-300K.
The facility utilises Bruker's own xepr software for spectrometer operation and spectral manipulation. EasySpin, in combination with Matlab, can be utilised for spectral simulation. Xepr2csv, a simple command-line conversion program written for those without access to either Matlab/EasySpin or xepr is available for download for free from the facility site.
The Facility is equipped with a Bruker Elexsys E580 EPR spectrometer, capable of X- and Q-band (9.5, 35GHz respectively) frequency operation, and a Bruker Elexsys E680 EPR spectrometer capable of W-band (95GHz) frequency operation.
They are both upgraded to provide a range of experimental options, from the 'standard' continuous wave field swept experiments to more exotic techniques such as pulsed ENDOR and pulsed ELDOR. The E580 is equipped with a first generation SpecJet and PatternJet, while the E680 uses second generation hardware. The E580 uses a watercooled magnet system, while the E680 utilises a 5.5T cryomagnet.