Cosmic-ray Isotope Measurements with HELIX

Abstract

HELIX (High Energy Light Isotope eXperiment) is a balloon-borne experiment designed to measure the chemical and isotopic abundances of light cosmic ray nuclei. Detailed measurements by HELIX, especially of $^{10}$Be from 0.2 GeV/n to beyond 3 GeV/n, will provide an essential set of data for the study of propagation processes of the cosmic rays. HELIX consists of a 1 Tesla superconducting magnet with a high-resolution gas tracking system, time-of-flight detector, and a ring-imaging Cherenkov detector. The instrument is scheduled to have a long-duration balloon flight out of McMurdo Station during NASA's 2020/21 Antarctic balloon campaign. Here, we discuss the scientific goals and the design of the experiment, and report on its current status.