The Bruker EMX 200U EPR is a Continuous Wave(CW) sweep EPR, equipped with an ER4102ST universal X-band resonator, rectangular TE102 cavity, operating at a nominal frequency of 9.75 GHz.

The EMX Signal Channel can be operated at any modulation frequency between 6 kHz and 100 kHz, and has unsurpassed phase resolution and stability. It incorporates automatic digital tuning of any cavity to any modulation frequency, without using the classical "tuning-box" required with each cavity.

A high stability, digitally controlled Hall field controller allows you to sweep the magnetic field to over 8,000 Gauss (0.8 Tesla) and set field values with a resolution of under 1 mG (0.1 µT). The field is produced by a water-cooled magnet with a pole diameter of 10 inches, and air gap of 64 mm, using a 2.7 kW power supply.

Extensive variable temperature capabilities include both an Oxford Instruments continuous flow liquid helium cryostat, and a liquid nitrogen finger cryostat. An ER4114HT high-temperature cylindrical cavity now on order will allow sample temperatures up to 1000 C. This instrument was upgraded in 1998 and is in outstanding condition.

Don Heyse working with EPR