Electron Paramagnetic Resonance Spectrometer with Frequency and Magnetic-Field Modulation

摘要

A new electron paramagnetic resonance spectrometer is described. Its distinctive characteristic is the use of combined frequency-and magnetic-field modulation. Its structure is simplified as a result. Due to the use of magic tee balance adjustment and application of a positive bias voltage to the microwave crystal diode, its noise level is reduced almost that of thermal noise. It has increased detection efficiency and higher sensitivity. The signal of 5 x 10 to the -9th power molar DPPH can be observed on the oscilloscope. The signal-to-noise ratio is 2:1. The working frequency is 9690 Mc. (Author)