Performance of ESR Spectrometers

Poole (92) and by Wilmshurst (93). Excellent summaries of techniques were recently given by Ingram (94) and Ayscough (95). In this section we intend to present only a simple abstract of the salient features concerning the performance of ESR spectrometers, and the basic problems associated with experimental analysis of ESR data. 

Performance of ESR Spectrometers In general the most desirable features in a spectrometer are high resolution and sensitivity. Resolution of an ESR spectrometer depends basically on the time stability of the magnetic field and the microwave frequency as well as the homogeneity of the magnetic field. The spectrometer sensitivity, expressed in terms 

The field is modulated at some audio- or radio-frequency (usually -100 kHz), and this produces signals at the crystal detector whose output can be amplified at the modulation frequency. In general, sensitivity is higher at high-modulation frequencies because of the linear variation of excess crystal noise with the inverse of frequency. However, the recently developed Schottky diode makes it possible to obtain good sensitivity at relatively low frequency. 

Silsbee (98) has attempted to use Fourier transforms of experimental spectra as compared to the model ones. 

FIGURE 5. Spectra obtained from a weak solution of DPPH in benzene using a CAT  

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