SU1485097A1 - Method of recording signals of electron paramagnetic resonance - Google Patents

Description

The invention relates to technical physics and can be used in the development of radio-spectrometric equipment.

The purpose of the invention is to improve the accuracy and reduce the measurement time.

The drawing shows a diagram of the device for implementing the method.

The radio spectrometer consists of a working resonator 1 placed between the poles of an electromagnet 2 connected to a magnetic field control unit 3, a measurement unit 4 connected to a working resonator 1 and connected to an information input of a controlled low-pass filter 5 and an input of a function converter 6 whose output is connected with a control input of a controlled low-pass filter.

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(57) The invention relates to technical physics and can be used in the development of radio-spectroscopic equipment. The purpose of the invention is to improve the accuracy and reduce the measurement time. The method includes the passage of resonant conditions at a constant speed, the detection of resonance signals ⁸ and the subsequent low-frequency filtering, which is carried out by setting the integration time constant at each point of the recorded spectrum inversely proportional to the modulus of the derivative of the EPR signals. 1 il.

Registration of signals of electron paramagnetic resonance (EPR) is as follows.

The test sample is placed in the working resonator 1 located between the poles of the electromagnet 2 connected to the magnetic field control unit 3. Measurement unit 4 generates resonance conditions necessary for observing EPR signals. In the process of a linear sweep of a polarizing magnetic field, carried out by an electromagnet 2 under the influence of the magnetic field control unit 3, the EPR signal is recorded at the output of the low-pass filter 5, where its low-frequency filtering is performed to improve the signal-to-noise ratio. Automatic selection of the optimal value

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the integration time constant of the low-pass filter 5 is implemented using a functional transducer 6, forming a signal used to control the value of the integration time constant, the value of which is inversely proportional to the derivative of the detected EPR signal. In this case, the change in the time constant of the integration of the low-pass filter 5 occurs in accordance with the nature of the change in the recorded EPR signal — the value of the constant 15 integration time decreases with increasing rate of change of the recorded signal, i.e. with an increase in its derivative, and increases with a decrease in the rate of change of the signal.

Studies show that the proposed method of registering EPR signals can significantly reduce the bandwidth of the registration system of an EPR radio spectrometer in the areas of the recorded signal with a low rate of change and, therefore, increase the signal-to-noise ratio.

The proposed registration method provides an increase in the accuracy of recording EPR signals, in particular, the measurement accuracy of such parameters of resonance absorption lines as peak and integrated intensity, which is of great importance for improving the accuracy of measuring the concentration of paramagnetic centers in the samples under study.

Claims (1)

Claim The method of registration of electron paramagnetic resonance (EPR) signals, including the exposure of the sample to constant and perpendicular radio-frequency magnetic fields, detection, low-frequency filtering by integrating an EPR signal, characterized in that, in order to improve accuracy and reduce measurement time, integration is performed with a constant time equal to the value inversely proportional to the modulus of the derivative of the detected EPR signal.