Optical pump magnetometer gradient tolerance measuring device

[0014] The present invention will be described in detail below in conjunction with the drawings:

[0015] The optical pump magnetometer gradient tolerance measuring device of the present invention mainly includes a horizontal base 1, a gradient generating coil 2, a horizontal connecting rod 3, a bubble level 4, a connecting rod level adjusting device 5, and an optical pump probe installation fixture 6 , Laser rangefinder 7, precision current source 8, and measurement and control module 9. The measurement and control module 9 calculates the output current required to generate a specific magnetic gradient according to preset parameters such as probe position, probe size, coil turns, and coil radius, and passes The USB interface controls the precision current source 8 to output a specific current to the gradient generating coil 2. The gradient generating coil 2 is installed on the horizontal base 1 and the position is adjusted by the bubble level A4. The gradient generating coil 2 generates a magnetic gradient in the surrounding space; on the horizontal connecting rod 3 Equipped with the light pump probe installation fixture 6, and adjust the horizontal connecting rod 3 to be parallel to the axis of the gradient generating coil 2 through the bubble level A4, the bubble level B and the connecting rod level adjustment device 5; the light pump probe 11 to be measured and the magnetometer host to be measured 12 Connect and install it in the optical pump probe installation fixture 6 (the optical pump probe installation fixture 6 can be adjusted by the probe position adjustment device), and measure the distance from the center of the gradient generating coil 2 to the optical pump probe 11 to be measured by the laser rangefinder 7 . The measurement and control module 9 includes the number of coil turns N, the coil radius R, the area C (OA, r, OB) where the probe is located, and the set gradient value dT according to the input parameters. 0 , The output parameters include the output current I, the actual gradient range dT in the area C 0 , DT 1 , And finally ensure that the minimum actual magnetic gradient in area C is greater than or equal to dT 0.

[0016] figure 1 Among them, the optical pump probe 11 to be tested and the host 12 of the magnetometer to be tested are the optical pump magnetometers to be tested. The horizontal base 1 completes the horizontal fixation of the gradient generating coil 2, the connecting rod level adjustment device 5, the bubble leveler ensures that the horizontal connecting rod 3 is in the horizontal plane and the coil axis is parallel, the optical pump probe installation fixture 6 completes the installation of the optical pump probe 11 to be measured, laser The distance meter 7 completes the distance measurement from the center of the coil to the optical pump probe 11 to be measured. The measurement and control module 9 calculates the output current required to set the magnetic gradient according to preset parameters such as probe position, probe size, coil turns, and coil radius. , And control the precision current source 8 to output a specific current through the USB interface to ensure that the minimum value of the magnetic field gradient in the area where the optical pump probe 11 to be measured is located is greater than the set magnetic gradient.

[0017] figure 2 Implement steps for gradient tolerance measurement. Among them, the measurement preparation completes the connection of the relevant instruments; the level adjustment of the base can ensure that the axis of the coil is on the horizontal plane; the level adjustment of the connecting rod ensures that the connecting rod is on the horizontal plane and parallel to the axis of the coil; after fixing the probe on the fixture, adjust the laser measurement From the light point of the instrument to the probe, record the distance from the center of the coil to the probe. The measurement and control module 9 can calculate the output current required to generate a specific magnetic gradient according to preset parameters such as the number of coil turns N, the coil radius R, and the area where the probe is located (OA, r, OB), and control the output of the precision current source 8 through the USB interface Specific current I; after generating a given magnetic field gradient, check the working status of the magnetometer. If it works normally, increase the gradient and observe the working status of the magnetometer again. If it works abnormally, the last set magnetic field gradient value will be waiting Gradient tolerance of the magnetometer.

[0018] image 3 Calculate the model for the magnetic gradient. Taking the center O of the coil as the origin of the coordinates, the axis direction is Z, the vertical direction is X, and the horizontal direction is Y. When the number of coil turns is N, the coil radius is R, and the supply current is I, the Biot-Savart law The magnetic field vector at any point (x, y, z) in space can be calculated for,

[0019]

[0020] Among them, μ 0 Is the permeability in vacuum, and θ is the integral independent variable around the coil.

[0021] The gradient of the total field B along the Z direction in the area where the probe is located The minimum gradient generated is

[0022]

[0023] Figure 4 It is a diagram of the input and output parameters of the measurement and control software. The input parameters of the measurement and control software include the number of turns of the coil N, the radius of the coil R, the area C (OA, r, OB) where the probe is located, and the set gradient value dT 0 , The output parameters include the output current I, the actual gradient range dT in the area C 0 ~dT 1 , And finally ensure that the minimum actual gradient in area C is greater than or equal to dT 0.

[0024] It can be understood that for those skilled in the art, equivalent replacements or changes to the technical solutions and inventive concepts of the present invention should fall within the protection scope of the appended claims of the present invention.