Novel horizontal-bore superconducting solenoid design for quasioptical high-field electron paramagnetic resonance

A horizontal‐bore magnet and cryostat design is described that is specifically adapted to high‐frequency quasioptical electron paramagnetic resonance (EPR). The magnet is an 8‐T superconducting solenoid with an auxiliary superconducting sweep coil driven by permanently mounted current leads. The performance of the sweep magnet in this configuration is demonstrated using a lithium phthalocyanine single crystal standard, which gives peak to peak first derivative linewidths down to 19 μT. The specific advantages of the horizontal‐bore swept‐field design for quasioptical EPR include improved accessibility, sensitivity, and economy of operation compared with vertical‐bore magnets. © 2002 Wiley Periodicals, Inc. Concepts in Magnetic Resonance (Magn Reson Engineering) 15: 201–207, 2002