Abstract Summary/Description
The sPHENIX experiment at the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory is dedicated to exploring the properties of the quark-gluon plasma, a state of matter that existed mere microseconds after the Big Bang. By investigating high-energy particle collisions, sPHENIX aims to deepen our understanding of this exotic matter and its role in shaping the early universe. Central to the sPHENIX detector is the Hadronic Calorimeter (HCal), which measures the energy of hadrons produced in these collisions. The HCal's performance is critically dependent on the Sampling Fraction (SF), the ratio of energy detected in the active medium to the total energy deposited in the calorimeter. An optimized SF improves the detector's energy resolution and linearity, essential for precision measurements. The sPHENIX HCal at RHIC is composed of two parts: the Inner HCal (IHCal) and the Outer HCal (OHCal), using scintillator plates interleaved with aluminum and stainless steel, respectively. This study investigates SF using analytical methods and GEANT4-based simulations, finding consistent results. Variations in SF were observed in the OHCal, particularly in the chimney sector, due to differences in material composition and thickness. The IHCal exhibited smaller but more distributed SF variations. Across different z-vertex positions, the SF remained stable within an 8% variation in the HCal. These results enhance our understanding of HCal performance, enabling its optimization for improved energy resolution, a critical factor in achieving the sPHENIX experiment's goals of probing the early universe's matter properties.
