| Radio-frequency(RF)atomic magnetometer is an instrument that can measure alternating magnetic fields with extremely high sensitivity and has always been a focus of research and application.By inducing eddy currents in an object and measuring its response magnetic field,it is possible to detect and image objects at a distance.The response magnetic field may generate two-dimensional components in the transverse direction,but research on how to measure multiple directions of RF magnetic fields with RF atomic magnetometer applications is relatively rare.In order to measure the RF magnetic field in two directions simultaneously,a two-dimensional RF magnetic field measurement method is proposed in this paper,and the effectiveness is demonstrated.The method uses the amplitude and phase characteristics of the RF field in the output signal,and solves the equation group under the low-field approximation to obtain the size and direction of the RF field.This paper first introduces the development of magnetometer and studies the working principle of the rubidium atom RF atomic magnetometer.Secondly,an experimental platform for the atomic magnetometer is built.Based on the series expansion method and the quadratic polynomial method,the Helmholtz coil is optimized in design.In addition,a RF coil and a compensation coil are designed and calibrated,and all coils are characterized.According to the size of the cell,a heating device and a warming device are designed and made,which cell to a higher temperature.Then,the principle of measuring two-dimensional RF magnetic fields is discussed.Through calculation and experiment,it is determined that the radiofrequency magnetic field is proportional to the amplitude of the absorption component at a value below 1n T.The sensitivity is optimized to 6.5f T?√Hz.Finally,at the optimal sensitivity,the RF magnetic fields in the transverse plane with a size of 1 n T are measured.The experimental results show that the method proposed in this paper is feasible. |
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