Simulations of a Gas Jet Target Inside SOLARIS

            There are several complications of measuring the reaction rates of unstable nuclei, such as significant backgrounds present due to beam scattering, electrons from the target, radioactive decay products, or competing reactions from beam or target impurities. Gas cells and solid targets both present difficulties such as contamination from the various isotopes of the target and degradation. The Jet Experiments in Nuclear Structure and Astrophysics (JENSA) gas jet target eliminates these difficulties by providing a high density gas jet of target nuclei within a confined region. SOLARIS is a solenoidal spectrometer system that allows for high-resolution studies of direct reactions. Simulations allow us to assess the resolution and the transport properties of the solenoid spectrometer. Python code has been developed to simulate a gas jet setup inside of SOLARIS, giving us a preview of how this setup compares to the use of traditional targets like polyethylene.  Several reactions, representing examples of the kinds of measurements that may be studied with this device, have been simulated. The reaction type, nuclei involved, and magnet settings have all been varied. Through these simulations, the impact of jet hardware shadowing the particle tracks for future reaction studies will be assessed.