Q-Band EPR Resonator for Pulsed Dipolar Spectroscopy

The Q-Band LGR is optimized for pulsed dipolar EPR spectroscopy  (DEER/PELDOR, SIFTER, RIDME, DQC, etc.). The probe can be operated from 2 K to room-temperature and is compatible with standard cryostats such as the CF935. The probe is connected to the spectrometer using a standard WR-28 waveguide coupling. For pulsed EPR experiments the iris coupling can be easily (remotely) adjusted, without the need of changing the resonator frequency.

The Q-Band LGR was designed for small samples sizes and comes in two flavors:

• 1.6 mm sample OD to maximize Absolute Sensitivity
• 2.5 mm sample OD to maximize Concentration Sensitivity

For accurate temperature readings a temperature sensor is mounted right next to the sample space. Instead of relying on the cryostat temperature, this will give more accurate readings of the actual sample temperature.

Maximally overcoupled, the resonator has a loaded Q of < 85, corresponding to a bandwidth of > 400 MHz. The mechanism is designed with convenience in mind and the maximum bandwidth can be reliably achieved every time. Even at this low Q, the microwave conversion factor is > 5.1 G/sqrt(W).

For DQC experiments, the entire EPR spectrum has to be excited. At Q-Band, the TEMPO spectrum has a width of ~ 250 MHz. The Bridge12 QLP resonator is ideally suited for these type of experiments. With a bandwidth of > 400 MHz and a large microwave conversion factor the LGR is ideally suited to excite the entire nitroxed spectrum for DQC spectroscopy.