IQC Student Seminar Featuring Connor Kapahi

Neutrons have a long history at the forefront of precision metrology. Following in the footsteps of the first experiment that measured the effect of gravity on a quantum particle (the C.O.W. experiment), we aim to generate structured neutron momentum profiles and apply these states to measure the gravitational constant, big-G. The significant discrepancy between modern big-G experimental results underscores the need for new experiments whose systematic uncertainties can be decoupled from existing techniques. Previously, perfect-crystal neutron interferometers were used to measure local gravitational acceleration, little-g, unfortunately, the low neutron flux (a few neutrons per second) of these devices makes them impractical for precision measurements of big-G. The recently demonstrated Phase-Grating Moiré Interferometer (PGMI) offers an increase in neutron flux of several orders of magnitude while preserving the large interferometer area, and thus the sensitivity, of a perfect-crystal interferometer. This device possesses a set of systematic uncertainties that are independent from those in existing techniques that measure big-G. In this talk, I will discuss the feasibility of measuring big-G using a neutron PGMI apparatus with a test mass on the order of 1 tonne. Further, I will address how we can optimize this setup to maximize the phase shift from a 1-tonne mass and quantify the various sources of uncertainty in the proposed experiment.