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Case 12  Application of ATA-4012 high voltage power amplifier in nuclear magnetic resonance oscillator

Name of experiment：noninterference method for measuring the lateral relaxation time of an alkali metal magnetometer in a nuclear magnetic resonance oscillator

Research direction：quantum precision measurement

Experiment content：

The transverse relaxation time τ2 of the embedded alkali magnetometer is an important parameter to characterize the performance and working state of the nuclear magnetic resonance oscillator system.

The proposed method for measuring transverse relaxation time τ2 is to apply a sweeping magnetic field in the X-axis direction, then measure the amplitude-frequency response curve of the magnetometer in the X-axis direction, and finally obtain τ2 from the 3dB bandwidth of the amplitude-frequency response curve.

A detailed and strict theoretical derivation based on the perturbation-iteration method is given to prove the rationality of the measurement method. Then, simulation experiments and practical experiments are carried out to verify the effectiveness and high accuracy of the measurement method.

Since all the sampling frequency points in the sweep range are far away from the NMR frequencies of 129Xe and 131Xe, any influence on the nuclear spin can be avoided. Therefore, this measurement method can provide a non-interfering way to measure τ2, which helps to monitor the state of the NMR oscillator system under normal operation conditions.

Purpose of experiment：the atomic gas chamber of the experimental system needs to be heated by a heating plate, which can be driven by an amplified current output from a power amplifier.

Test equipment：heating plate, insulation device,ATA-4012 high voltage power amplifier

Experimental process：

Temperature control program and data acquisition card equipment output appropriate range, high frequency (hundred of KHz) of high precision heating voltage control signal, input to the power amplifier. In constant current mode, the output current parameters of the amplifier are adjusted to about 1A, and then the power amplifier amplifies the input electrical signals. The output current of the power amplifier is connected to the heating plates in series, and the heating plates are evenly distributed in the insulation device to carry out constant temperature heating of the atomic gas chamber.

Result of experiment：

The temperature stability of atomic gas chamber can reach ±0.002℃, and the heating temperature can reach at least 130℃.

Amplifier's role in this experiment：

The high-precision output current of the power amplifier flows into the heating plates in series to drive the heating plates.