A thick liquid hydrogen target coupled to a Si tracker to investigate the structure of nuclei

One of the goals of modern nuclear physics is to understand the structure of nuclei, particularly at the limit of their existence, known as the dripline. This involves determining how many nucleons (neutrons and protons) can be added to a nucleus before it becomes unstable. The Facility for Rare Isotope Beams (FRIB) at MSU provides an unparalleled opportunity for such investigations due to its capability to produce intense beams of rare isotopes. These beams are then used to create collisions with a target of choice in order to populate excited states in desired nuclei of interest.
The MoNA (Modular Neutron Array) collaboration is at the forefront of studying the structure of unbound nuclear states using invariant-mass methods. The experimental setup currently includes advanced detector arrays positioned to capture data from the (p,2p) reactions that take place. The reactions happen at the target, and then particles are separated with a sweeper magnet, where charged particles are channeled towards the drift chamber and neutrons proceed to the MoNA-LISA array. To enhance resolution and luminosity, a new development is underway to use a liquid hydrogen (LH2) target in lieu of the conventional solid targets that will be surrounded by the CAESAR gamma ray detector. This involves the integration of a thick liquid hydrogen (LH2) target coupled with a silicon (Si) tracker array.
The precise positioning of LH2 targets within detectors is critical for achieving accurate measurements, and this new setup aims to significantly improve both the spatial resolution and the overall luminosity of the experiments. To determine the optimal geometry and assess the vertex resolution capabilities of this enhanced setup, NPTool simulations of the quasi-free scattering (QFS) reaction are being employed. These simulations are crucial for designing an experimental arrangement that maximizes the potential of the FRIB's intense beams, thus advancing our understanding of nuclear structure at the extremes.