Development of a new apparatus for precision gravity measurements with atom interferometry

The computational work in this doctoral thesis describes the virtual realization of an atom interferometry based gravity gradiometer aiming at an accurate determination of the Newtonian gravitational constant G. The experimental design and interferometric scheme is different from all the measurements published so far. This virtual realization aims on the cancellation of ambient gravity gradients from their exact - conjugate fictitiously generated gravity gradients from our scheme, therefore resulting in a relative accuracy of 10 raised to minus 6 using only 10000 atoms in each cloud. Precise simulations are developed meticulously incorporating all the aspects of interferometric scheme with well - characterized tungsten source masses measuring the phases accumulated by the atomic clouds traversing the path resulting from Mach - Zehnder gravimetric sequence in the presence and absence of the aluminium platform supporting the new configuration of source masses. One other possible source mass design made out of copper (assuming the geometrical configuration analogous to the aluminium platform) is also considered, so as to complete a comparative study of phase acquisition due to different designs of source masses arising from different total gravitational potentials and material densities. These precise simulations also target at achieving the phase noise minimization for the interferometric signal in presence of gravity, as a result to completely eliminate the presence of systematic errors. The simulation in this thesis incorporates a presence of a finite - sized solenoidal coil affecting only second half of the upper interferometer resulting in the opening of ellipse, henceforth the systematic errors which are faced while performing the elliptic fit will be completely eliminated. The gravity gradiometer as per the new design in the thesis is currently being built for the measurement runs of continuous data acquisition to be possible. The phase noise minimization condition for the modified experimental scheme has been performed and is reported in this thesis. Lastly, the gravity gradient cancellation for both the two source mass designs with a relative uncertainty of 0.1%, 0.5% and 1.0% have been performed and is reported in this thesis.