SU303571A1 - - Google Patents

Description

This invention relates to high resolution nuclear magnetic resonance spectroscopy techniques.

A device is known for the synthesis of the excitation frequency and the sweep of β-magnetic spectra (resonance of fluorine in a nuclear magnetic resonance spectrometer, which contains an intelligent oscillator with intelligent frequencies of protons and of fluorine in the same (Polarizing field. The cnciKTpoB 3 sweep of this device is carried out using a grid of reference frequencies created by a number of low-frequency / juvartz oscillators and added x (To the fundamental resonant frequency of the fluorine for obtaining fnr-footed sweep steps. VNA scan spectra within these stages is effected .posredstvom varying floor Reese | uyuschego floor in arrangement and Ali. ZiruemO | GO sample Dia pazon smooth "e-discontinuous scanning in this device is 1 kHz.

The disadvantages and pz of the known devices are:

a) the inability to record the spectra of the resonance of the fluorine / with a continuous scan in the entire range of changes in the chemical shifts of the fluorine resonance of about 20 kHz at (56 MHz operating frequency of the required frequency aiahiazone (w known device has 20 such resonators).

h) the need to adjust the frequencies of these resonators with an accuracy of a fraction of a hertz for

ensure uniform sweep;

d) the impossibility of expanding the dia (continuous sweep range and, consequently, the impossibility of reducing the number of low-frequency reference quartz resonators due to distortion; {in homogeneity of the polarizing field caused by the sweep currents.

The aim of the invention is to synthesize a stable stimulating frequency and a continuous, linear and stable sweep over the entire range of resonance spectra, as well as to provide stepwise nonenoii sweep spectra with a minimum number of frequencies in the onopHoii grid. For this in: the proposed device in

the chain of synthesis of the exciting frequency. fluorine frequency resonance: proto.nov between the mixer frequency | protons with the frequency of the differential-frequency crystal oscillator included controlled differential difference generator

frequencies with a phase auto-pitch circuit; frequencies of the beating of oscillations of this generator and the Yuvartsev difference-frequency generator. In addition, between a coil / field sweep and a coil; a quadratic gel current correction cable, which, during a cold sweep, drops the sweep current into; the coils of the corrected square of the first gradient. To create the grid of olor frequencies, a low-frequency harmonic generator is used, which is connected through a directing filter to the phase-locked circuit of the frequency of the controlled differential frequency generator. On the chart: but the block diagram of the thrasher device is shown. The block diagram contains: a varon generator / resonant frequency of the nrotons (60 MHz), a quartz generator 2 difference frequency (3.6 MHz.}, A unit generator 3 difference frequency (3.6 ± 0.01 MHz), a mixer 4 frequencies generators 2 and, 7 differential frequency, amplifier 5 beats of oscillations of differential frequency generators, analog frequency meter 6 (sensor converter-voltage), circuit 7 compared nanometers, amplification of constant current 8, varican-9, mixer 10 of the resonant frequency nanotoneB frequency of controlled oscillator, filter} II frequency 1 1 resonance fluorine a {56.4 ± 0.01 MHz}, amplified fluorine 12 resonance frequency of fluorine, a balanced modulator, and "3" anfrequency quartz oscillator of 14 harmonics (the main frequency is 4 kHz}, filter 15 of the oscillator (4, 8, 12 16 and 20 kHz}, indnkkat. P 16 zero beats, mode selector 17, divider to 18 and coil 19 koremtsni Square quadrometer of laser zero spectrometer. The device can work: in two modes for visibility from non-switch 17. When the switch is open, the switch is open 7 HOiCTyiHaeT at the time. The CjHCKTpoMeTpa Instrument Registration System. In scheme 7, this voltage is compared to the output voltage of a measuring meter 6. and the difference of these outputs is a dc amplifier and 8 nvari (Q1 controls the frequency of the generator-3. The oscillation of this heater on the mixer 4 smosh-I1 is oscillating with a quartz oscillator 2 differential frequency. The oscillators of the oscillators 2 n 3 are amplified by the amplifier 5 and they are continuously measured by the frequency meter 6. The co.vacunity of the block: 4–9 is the value of the modulation and stabilization of the frequency of the controlled oscillator.). The oscillations of this generator come to the mixer -10, in which they are mixed with the "K1var / tsev: oscillator / resonant frequency of the nrotons, Nstyulzemoto for each channel of the NORONIUS st1bilnza1N, and after the meter. The difference frequency of these oscillations, corresponding to the resonance of the fluorine, through the filter // n amplifier 12 is fed to the spectrometer sensor for 1 excitation of the resonance of the fluorine. With a linear time change in the voltage of the input circuit of Scheme 7, the resonant frequency of the fluorine transmitted to the filter sensor e // changes linearly, and this results in a frequency sweep of the spectra resonance ;; der fluoride. ; Prn closed-M switch 17 to the input. Comparison 7 is supplied with a fixed reference pole of the same. The resulting irregular beats of oscillations of the 2 and 5 s amplifiers of the 5 and the modulator, 13, to the other input, through which the harmonic HHiK generator oscillates, which correspond to ONE of the harmonic of the harmonic generator mNNN M, are fed to the other input. A balanced module modulator 13 blinds to varnkan 9 to control the frequency of the oscillating generator 3 and is simultaneously monitored by the indicator 16 null x bie. At a certain value of the reference voltage in the Scheme 7 compared, the mode sets the a.automatic phase control of the controlled oscillator 3, but the harmonics of the harmonic generator 14 selected, which ensures accurate fluoride resonance excitation frequency to one of the fixed sources. The number of ethnh appearances is determined by the fundamental frequency of the quartz oscillator of harmonics 14 and the required bottom range (usually 20 kHz of zero 14,100 e} n corresponds to the number of filters in the filter | /, 5. The sweep of the spectra in this frequency is equal to the internal frequency levels of excitation carried out by a polarisable region of a known enoi. One way, with the expansion of diaonion times, the rotation and the decrease in the number of stuneni excitations, waiting (and, therefore, the number of filters in the filter 15), part current is scanned through the current divider 18 is connected to the cath 19 square quadrant gradient correction for the tromometer .dl of the same gradient arising from the sweep currents. Thanks to this, the proposed sweep of the field sweeps to 4 kHz and the number of frequency steps decreased to 5 I instead 20 in the famous Stooyspve). g s and ii synthesis of spectro: in a magnetic resonance spectrometer, containing the frequency of the resonance from a proton resonance, which is in the case of a Yuvarnev resonant frequency generator, protons, quarts differential frequency generator, and a mixer, different that, with the newness of stability and linear sweep in the whole region of der fluorine resonance, at the rate of synthesis of the exciting frequencies :-) between the mixer and the square differential frequency generator, the controlled variable i-generator of the difference frequency with not phase ; yu av top-tuning of the frequency of the beats of the oscillations of this generator, p 1 of the 1-oscillator generator of the raio-frequency.

The goal is to improve the measurement accuracy between the field coil coils and the quadratic gradient correction caTymiKaMH, and its field, the current divider included, ABOUT, and the portion of the current sweep in the quadratic gradient correction coils.

3. The device according to PP. 1 and 2, characterized in that, in order to increase the measurement complexity, into the circuit of an auto-tuning frequency 1KC of frequency y; the controlled differential frequency generator is via a tunable key filter B1 low-frequency Schwarz harmonic generator.

 Proton Istabilization Channel) QJ Sensor (Excitation of the Fluor resonance of the A Sensor to the Sensor (& V6dcvn) Tension unwrapping or constant voltage О Current dissipation &