SU750354A1 - Method of investigating electron paramagnetic resonance saturation line - Google Patents

Description

(54) METHOD FOR STUDYING ELECTRON PARAMAGNETIC RESONANCE LINE SATURATION

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And shaving is in the field of electric / joHHoro pair of impedance resonance (EPR) and can be used in the design of EPR spectrometers.

There are known methods for studying the saturation of an EPR line, in which the magnetic field modulates so that the modulation amplitude is greater than the line width, and the transit time through the line is much shorter than the time of scin-lattice relaxation, and a small portion of the EPR line is pulsed synchronously with the modulation frequency. .

However, these methods do not allow to investigate the behavior of the line during the action of saturating high-frequency pulses due to the parasitic signals arising in the process.

There is also known a method for studying the saturation of an EPR line, which involves exposing the shear system to a continuous saturating high-frequency field, passing through a resonance by a polarizing magnetic field modulated by a sinusoidal variable with a slow-wave, compared to the spin-lattice relaxation rate, moreover, the modulation amplitude is less than the width of the studied shspy (the method of sequential homing) 2.

The disadvantage of this method is that it does not ensure that the registration of the temporal characteristics of the saturation process due to the time averaging of non-equilibrium magnetizing is unfeasible. high frequency and modulation fields.

The purpose of the invention is to obtain temporal characteristics of the process of saturation of the EPR line.

Claims (1)

The goal is achieved by a t & l that the half-field of a further magnetic field is modulated by rectangular pulses, the follow-up period of which is longer than the spin-lattice rvpax pulse, the amplitude is greater than the width of the line under study, the rise time of the pulses is shorter, and the duration is longer The ZPR signal is observed at a fixed moment of action of the modulated pulse, provided that during the registration of each line point the change in the constant component of the polarizing magnetic field is small pared with the width of the line under study. In this case, the radio frequency radiation, which starts burning, begins to interact with this point of the line after it establishes the resonant conditions for it by modulating the field of its magnetic field and during the action of the modulating pulse leads to its saturation. Since by the time of the next modulating pulse, the line is fully restored, then sequentially registering the EPR signal at each point of the spindle at a fixed moment of action of the modulating pulses, an instantaneous value of the EPR for the given time point is obtained. Change the moment nabhpodeni. allowing you to investigate the change in the EPR line over time; Example. The constant microwave power (25 mW) of the frequency 9.5 GHz was supplied to a quartz sample irradiated with neutrons (line 2.9 e) placed in a resonator and a constant magnetic field. The magnetic field was modulated by pulses with a duration of 5 ISS, rise and fall times of about 110 and an amplitude of about 4.5 Oe. The modulation pulse frequency was 10 kHz, and the sweep speed Mai Hii THoro field was about 0.5 e / s. The broadband signal processing system allowed us to test the signal at the points of time of interest and register it. 4 The use of the proposed method provides an instantaneous value of the ESR line, which makes it possible to measure the change in the characteristics of the line over time under the influence of the high frequency field. The invention of the method for examining the expressions of an electron paramagnetic resonance line, which consists in exposing a spin system under study to a high-frequency pinching magnetic field and passing through a resonant region of a line imposing a linearly varying polarizing magnetic field, characterized in that The magnetic field is modulated by rectangular pulses, the period of which is longer than the time of the spin-lattice relaxax , the amplitude is greater than the width of the studied broadband, the rise time of the pulses is shorter, and the duration is longer than the time of saturation of the measured points of the line, and the EPR signal is observed at a fixed moment of action of the modulating pulse, provided that during the registration of each point of the line the change of the constant component The polarizing magnetic field is small compared with the width of the line under study. Sources of the wide formation accepted in the external view during the examination 1. Lebedev Ya. S., Muromtsev V.I. ZPR and relaxation of stabilized radicals. -M., Himi, 1972, p. 1282. 4. Pool. Teh1shka EPR spectroscopy .I. , M., Mir, 197O, p. 386-396 (prototype).