SU1453280A1 - Radiospectrometer of magnetic resonance - Google Patents

Description

The invention relates to radio-, spectrometric apparatus and can be used to study the magnetic properties of a substance by the method of electron paramagnetic resonance, nuclear magnetic resonance, etc.

The goal of the invention is to increase the accuracy of the spectrum recording by compensating for the constant component of the recorded magnetic resonance signal with a non-monotonic change in its value.

The drawing shows a structural diagram of a radio spectrometer.

A magnetic resonance radio spectrometer contains a source of a polarizing magnetic field I, a sweep unit 2, a measuring resonator 3, a recording unit 4, a differential amplifier 5, an integrator 6, a digital-analogue converter 7, a control unit 8, the first and second 9 and 10, respectively, and a device 11 sampling and storage.

The radio magnetic resonance spectrometer operates as follows.

The studied paramagnetic sample is placed in the measuring resonator 3, located in the magnetic field created by the source 1 of a polarizing magnetic field, which is controlled by the scanning unit 2. The latter performs a sweep of the magnetic field according to a given law for passing through the resonant region of the spectrum. At the same time, from the recording unit 4, the electromagnetic field of ultrahigh frequency enters the measuring resonator 3 with the sample under study. When the resonance conditions are fulfilled, the measurement resonator 3 mismatches and a part of the microwave power is reflected, which is detected in the recording unit 4 as a magnetic resonance signal.

The magnetic resonance signal is recorded against the background of the constant component, which may be due to both the pickup of the magnetic field modulation signal and the presence of a wide spectral line.

The magnitude of the constant component in the proposed device is measured by integrator 6 as the average for the time of a single passage of resonant conditions in the forward sweep region

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magnetic field In addition, on the forward scanning section of the polarizing magnetic field, the scanning unit 2 generates a control signal, which turns off the control unit 8 and takes the storage sample device 1I to the sampling mode. As a result, the output of the digital-to-analog converter 7 maintains a voltage that compensates the constant component of the magnetic resonance signal calculated for the previous sweep period of the polarizing magnetic field, and the output voltage of the storage sampling device I 1 repeats the output voltage of the integrator 6.

At the end of the straight sweep portion, the sweep unit 2 puts the storage sampling device 11 into the storage mode and turns on the control unit 8. In this case, the voltage corresponding to the constant component of the magnetic resonance signal measured as the average value of the recorded magnetic resonance signal during the passage of the resonant conditions on the forward sweep portion is recorded on the sample and storage device 11. The first and second comparators 9 and 10 compare the output voltage Uyp, the sampling and storage devices 11, and the output voltage of the input voltage to the digital-to-analog converter 7. If U ,. Iso, the first comparator 9, for example, is triggered. It produces a control signal, under the influence of which the control unit 8, made, for example, on the basis of a reversible counter controlling the digital-analog converter 7, changes the level of the output signal thus, in order to ensure an increase in the output voltage of a digital-analog converter 7. An inverter: an increase in the output voltage of the converter 7 will continue: until T, n & become equal to uug. This first comparator 9 returns to the initial state and fixes at the output of a digital-to-analog converter, 7 a voltage equal to the output voltage of the storage sampling device 11. If ICs, Uyex, then the second comparator 10 is triggered. It produces a control signal, under the influence of which the control unit 8

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changes the output signal level in such a way as to ensure a decrease in the output voltage of the test voltage of the digital-to-analog converter 7. As in the previous case, the decrease of the output voltage of the digital-analog converter continues until the test finger is equal to and ... the second comparator 10 returns to its initial state and fixes at the output of the digital-to-analog converter 7 a voltage equal to the output voltage of the sampling and storage device II.

At the end of the reverse sweep, block 2 sweeps off 53280.

control unit 8, which excludes the possibility of changing the output voltage of the digital-to-analog converter 7 on the forward sweep section, which goes to one of the inputs of the differential amplifier 5 and compensates the constant component of the magnetic resonance signal coming from the output of the sweep unit 2 to the second input of the differential amplifier 5. At the same time, the scanner unit 2 converts the device I1 for sampling and storage to

15, the sampling mode, which makes it possible to memorize the constant component of the magnetic resonance signal.

Claims (1)

A MAGNETIC RESONANCE RADIO SPECTROMETER containing a polarizing magnetic field source, a scan unit, a measuring resonator, a recording unit, a differential amplifier, an integrator, a digital-to-analog converter, a control unit, and a comparator, the scan unit being connected to a source of a polarizing magnetic field and to the output to a polarizing magnetic field the first, the input of the control unit, the output of which is connected via a digital-to-analog converter to one of the inputs of the differential amplifier and the first input of the comparator , the output of the measuring resonator is connected to the input of the registration unit, the output of which is connected to the other input of the differential amplifier and the input of the integrator, and the output of the comparator is connected to the second input of the control unit, characterized in that, in order to improve the accuracy of spectrum registration by compensating for the constant component of the recorded a magnetic resonance signal with a nonmonotonic change in its magnitude, an additional sampling and storage device and a second comparator are introduced into it, moreover, the information input of the device The sampling and storage facility is connected to the integrator output, the control input to the second output of the scan unit, and the output to the second input of the first comparator> and to the first input of the second comparator, the second input of which is connected to the output of the digital-to-analog converter, and the output is connected to the third input control unit. SU ... "1453280 1 1453280