Hypernuclei offer a unique approach to investigating hyperon-nucleon interactions. However, their extremely short lifetimes, on the order of sub-nanoseconds, pose significant experimental challenges. The HYpernuclei Decay at R³B Apparatus (HYDRA) experiment, designed for operation within the R³B setup at GSI/FAIR, aims to perform heavy-ion collision experiments with the primary objective of performing high-precision invariant mass spectroscopy of light hypernuclei.This thesis presents the development of the HYDRA Time Projection Chamber (TPC) specifically designed for tracking π − produced from hypernuclear decays within the GLAD magnet of the R³B. The TPC incorporates a double-layer wired drift field cage with a drift distance of 300 mm and an active area of 256 × 88 mm2. A hybrid amplification stage was implemented, comprising a Gas Electron Multiplier (GEM) and a Micromegas detector. This configuration is expected to achieve an ion back-flow of less than 1%.The design of the field cage was optimized through two-dimensional simulations employing the finite element method and Monte Carlo techniques to ensure a homogeneous drift field. Electron drift displacement was determined to be less than 250 µm at the edge of the active region and less than 200 µm in the central regionof the TPC.The gain performance of the TPC was characterized using an X-ray source. By adjusting the high voltage applied to the electrodes, the influence of varying high voltages in different regions on the overall effective gain of the TPC was quantified.The TPC was successfully commissioned with a front-end readout system incorporating multiplexing boards and digitizing readout electronics based on the GET system. Subsequently, its tracking performance was assessed through measurements of laser tracks generated by a 266-nm ultraviolet laser source and reflected into the drift volume by micromirror bundles, which were integrated within the TPC. A tracking algorithm was developed to reconstruct these laser tracks. Experimental results demonstrated a spatial resolution better than 3 mm in the drift direction, while the pad plane resolution did not meet the desired 200 µm requirement.Finally, the influence of magnetic fields on the drift electron trajectories was investigated within the GLAD magnet at magnetic field strengths ranging from 0 to 0.92 T.
Ji Liancheng (Wed,) studied this question.