Design and characteristics of a WEP test in a sounding-rocket payload

TL;DR

This paper details the design of a sounding-rocket experiment, SR-POEM, to test the weak equivalence principle with high precision using laser gauges during free fall.

Contribution

It introduces a novel experimental setup for testing the weak equivalence principle with unprecedented accuracy in a sounding-rocket payload.

Findings

Achieved measurement uncertainty of < 2 x 10^-17 after eight drops.

Used laser gauges with an Allan deviation of 0.04 pm for precise measurements.

Implemented payload inversion to reduce systematic errors.

Abstract

We describe SR-POEM, a Galilean test of the weak equivalence principle that is to be conducted during the free fall portion of the flight of a sounding rocket payload. This test of a single pair of substances will have a measurement uncertainty of {\sigma}({\eta}) < 2 10^17 after averaging the results of eight separate drops, each of 120 s duration. The entire payload is inverted between successive drops to cancel potential sources of systematic error. The weak equivalence principle measurement is made with a set of four of the SAO laser gauges, which have achieved an Allan deviation of 0.04 pm for an averaging time of 30 s. We discuss aspects of the current design with an emphasis on those that bear on the accuracy of the determination of {\eta}. The discovery of a violation ({\eta} \neq 0) would have profound implications for physics, astrophysics and cosmology.