A new application of emulsions to measure the gravitational force on antihydrogen

TL;DR

This paper proposes using advanced emulsion film technology to measure the gravitational acceleration of antihydrogen with unprecedented spatial resolution, aiming to test the weak equivalence principle more precisely.

Contribution

It introduces a novel application of vacuum-compatible emulsion films to improve the spatial resolution of antihydrogen free-fall measurements in the AEgIS experiment.

Findings

Achieves approximately one micron spatial resolution in antihydrogen free-fall measurements.

Enhances the precision of gravitational acceleration measurement by an order of magnitude.

Demonstrates the feasibility of using emulsion films in vacuum environments for fundamental physics tests.

Abstract

We propose to build and operate a detector based on the emulsion film technology for the measurement of the gravitational acceleration on antimatter, to be performed by the AEgIS experiment (AD6) at CERN. The goal of AEgIS is to test the weak equivalence principle with a precision of 1% on the gravitational acceleration g by measuring the vertical position of the anni- hilation vertex of antihydrogen atoms after their free fall in a horizontal vacuum pipe. With the emulsion technology developed at the University of Bern we propose to improve the performance of AEgIS by exploiting the superior position resolution of emulsion films over other particle de- tectors. The idea is to use a new type of emulsion films, especially developed for applications in vacuum, to yield a spatial resolution of the order of one micron in the measurement of the sag of the antihydrogen atoms in the gravitational field. This is an order of magnitude better than what was planned in the original AEgIS proposal.