The HELIX Drift Chamber Tracker Design, Analysis and Calibration

The High Energy Light Isotope eXperiment (HELIX) is a balloon-borne superconducting magnet spectrometer designed to measure abundances of light cosmic-ray isotopes. HELIX, which undertook its first engineering flight in the Spring of 2024, identifies cosmic rays through measurements of their velocity, rigidity and charge. These measurements, and in particular, measurements of beryllium isotopes up to 10 GeV/n will be used to investigate cosmic-ray propagation models. The magnetic rigidity measurements are performed using a Drift Chamber Tracker (DCT), housed within a 1 Tesla superconducting magnet which deflects incoming cosmic rays. Three planes each containing seventy-two layers of sense wires are used to measure the positions of the deflected cosmic rays with a spatial resolution goal of 70 μm for Z>3. To ensure a precise gas composition and drift field a collection of housekeeping sensors was used, resulting in the DCT performing successfully in the flight. Presented here are details of the design and construction of the DCT as well as calibration and preliminary analysis of flight data.