Toward a Measurement of the Antihydrogen Free Fall

13 Jun 2018, 11:40
20m
Aachen

Aachen

RWTH Aachen University 52074 Aachen, Germany
Talk CPT

Speaker

Andrea Capra (TRIUMF (CA))

Description

In recent years, increasingly larger amounts of cold antihydrogen has been confined in the ALPHA magnetic trap [1] and has become available to perform precise measurements of its spectrum [2, 3]. Owing to this advancement, the Universality of Free Fall, a pillar of General Relativity, is put to test in a novel apparatus, named ALPHA-g, scheduled to take its first data in 2018. The ALPHA-g apparatus is designed to confine antihydrogen in a magnetic trap whose axis is aligned to the Earth’s gravitational field, i.e., it is vertical. The magnetic trap is constituted by an octupole magnet, which provides the radial confinement, and a set of “mirror” coils, which provide the vertical confinement. The antihydrogen gravitational mass can be inferred via the measurement of the annihilation distribution of antihydrogen under the influence of gravity. A crucial piece of equipment to perform this measurement is the radial Time Projection Chamber, or rTPC, that enables the identification of the antihydrogen annihilation position.
In this talk, I will give an overview of the ALPHA-g experiment, with an emphasis on the annihilation detectors.

[1] Ahmadi, M. et al., Nature Comm. 8, 681 (2017)
[2] Ahmadi, M. et al., Nature 541, 66 (2017)
[3] Ahmadi, M. et al., Nature 557, (2018)

Primary authors

Presentation materials