Measurements and 3D reconstruction of antimatter annihilations with the ASACUSA Micromegas Tracker

The aim of the ASACUSA-CUSP experiment is to form a beam of antihydrogen atoms for in-flight precision spectroscopic measurements. This is performed by trapping and mixing antiprotons and positrons in a common nested-well potential, which is sitting in a double-cusp magnetic field with minimum-B field configuration. We have built a tracking detector, the ASACUSA Micromegas Tracker (AMT) [1], to monitor and resolve annihilations on-axis from annihilations on the trapping electrode walls of the experiment, which latter is a general signature of antihydrogen formation. Data taken during the summer of 2015 is presented in order to demonstrate the first performance of the AMT detector. In particular, data from on-axis trapping and slow extraction of antiprotons is used to illustrate the vertex reconstruction capability of the detector.