## Honors College Theses

#### Date

2017

#### Major

Physics (B.S.P.)

#### Document Type and Release Option

Thesis (open access)

#### Faculty Mentor

Mark Edwards

#### Abstract

We propose a new atom interferometry scheme for making a precision measurement of Newton's Gravitational constant (Big G) using NASA's Cold-Atom Laboratory which is scheduled to be deployed to the International Space Station in 2017. The proposed interferometer consists of splitting a harmonically confined Bose-Einstein condensate into multiple pieces. In a perfect harmonic potential, all of the pieces come to rest at the same time, at which point the harmonic trap is turned off. These initially motionless condensate clouds then accumulate different phases due to the relative velocity they develop caused by the gravitational attraction of a nearby source mass. The trap is then turned back on bringing all of the clouds together at the same time, at which point they are again split to produce a central interference pattern. I have derived equations for the simulation of these schemes using a Lagrangian variational approximation of the solution of the 1D time--dependent Gross--Pitaevskii equation. I have used this method to evaluate different interferometer schemes rapidly and to understand how the resultant interference pattern can be used to obtain Big G.

#### Recommended Citation

Ashwood, Elizabeth, "Developing Tools for a Precision Measurement of Newton's Gravitational Constant using Atom Interferometry" (2017). *Honors College Theses*. 237.

https://digitalcommons.georgiasouthern.edu/honors-theses/237