Gradient detection system based on pulse pumping magnetometer

Abstract

The invention discloses a gradient detection system based on a pulse pumping magnetometer. The gradient detection system comprises a detection light laser, a polarizer, a radio frequency coil, a pulsetype pump light laser, a first atomic gas chamber, a second atomic gas chamber, a quarter-wave plate, detection light, a first reflector, a second reflector, a polarization detection system, a data acquisition system and the like. By setting the circular polarization gradient detection system of pump light or action modes of the pump light and probe light in the first atomic air chamber and the second atomic air chamber, magnetic field gradient values in the two air chambers are obtained. The gradient detection system combines two pulse pumping magnetometers together to share the pump light or the detection light, and subtracts the signals at the signal end or in the atomic gas chambers to extract the magnetic field gradient information, so that the consistency of the two magnetometers iseffectively improved, suppresses a signal-to-noise ratio, obtains a relatively accurate gradient value, reduces the size of the system, and saves the cost.

Description

technical field [0001] The invention relates to the technical field of pulse-pumped magnetometers, in particular to a gradient detection system based on pulse-pumped magnetometers. Background technique [0002] Magnetometers are used to detect weak magnetic field signals and are widely used in medicine, biology, geological exploration, material testing and other fields. In recent years, atomic magnetometers that use alkali metal atoms (such as potassium atoms, rubidium atoms, cesium atoms, etc.) Laser, atomic gas chamber, radio frequency coil and photodetector make up the system. The pulse-pumped magnetometer uses the optical pumping method to polarize the atoms to generate a macroscopic magnetic moment. Since the atoms in the magnetic field precess around the magnetic moment, the detection light detects the projection of the magnetic moment rotation, and the frequency of the rotation is proportional to The size of the external magnetic field can be obtained by analyzing t...

AI Technical Summary

Problems solved by technology

[0004] The traditional gradient detection method is to use the signal subtraction of two different magnetometers to obtain a differential signal. Since the signal amplitude and noise level of the two magnetometers are different, the error obtained by direct subtraction is relatively large, and the volume is large and the cost is high.

[0005] Traditional gradient magnetometers use optical pump magnetometers or fluxgate magnetometers to obtain gradient signals, but since most output signals of other types of magnetometers such as optical pump magnetometers or fluxgate magnetometers are relative voltage signals, calibration is required , cannot maintain absolute consistency

In addition, there are radio frequency coils in the traditional gradient magnetometer and the radio frequency coil cannot be shared. In order to avoid crosstalk between adjacent magnetometers, a certain distance needs to be separated, and the distance between the gradient magnetometers cannot be set arbitrarily, which limits the application of the gradient magnetometer.

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