Reasearch On High-flux Cold Atoms Source In Atom Interferometer

Cold atom interferometer has a broad application prospect in high precision inertial navigation,the measurement of fundamental physical constants,validation of basic laws of physics and geological exploration.The atom interferometer present towards high precision,high stability and miniaturization.A high flux of cold atoms is essential in high precision atom interferometer;this can realize the rapid loading of atom of Magneto-Optical Trap（MOT）,which can improve the output SNR of atom interferometer.This thesis is mainly expounding two key questions to achieve high flux of cold atoms.The first is a MOT which can ensure the accuracy and stability of measurement.The second is research to find coils which can trap more atoms and have large error acceptability.This thesis firstly researches method of two-stage MOT.The magnetic field coils of 2D-MOT and 3D-MOT have also been simulated and optimized.Saturated absorption spectroscopy and AOM are used to realize the frequency stabilization and frequency shift of laser.The detection principle of parameters（amount,density,lifetime and temperature）of atoms is recommended finally.These will set a solid foundation for the high precision atom interferometer.The main works of this thesis are as follows,1.The relationship between the design value of 2D-MOT and the flux of atoms is calculated.The design value of 2D-MOT including the length,radial diameter of the cooling zone and the pressure of ⁸⁷Rb in 2D-MOT.2.The magnetic field distributions of three different Anti-Helmholtz coils（rectangular,race-track and saddle）for 2D-MOT are calculated and analyzed by using finite element method.Further,the drift of zero position and gradient changing of magnetic field caused by the errors from the manufacture and installation process are also analyzed.Through comparative analysis the magnetic field distribution and the error effect,select a better coil structure which is suit to 2D-MOT is saddle coils.Besides,the scope of application and the tolerance of errors of three-dimensional magnetic field system of compact atom interferometers are also analyzed.3.The experimental procedure of cooling and trapping of atoms of ⁸⁷Rb using 2D-MOT is described.Saturated absorption spectroscopy and AOM are used to realize the frequency stabilization and frequency shift of laser.The frequency of pumping laser is locking to the transition of F=1 ?F￠=2,not the cross peak CO1′2,which can avoid the frequency shift of laser,reduce the using times of AOM,simplify the experimental light path.