Development of large acceptance multi-purpose spectrometer in Korea for symmetry energy

The Rare Isotope Accelerator complex for ON-line experiments (RAON) is a new radioactive ion beam accelerator facility under construction in Korea. The large acceptance multi-purpose spectrometer (LAMPS) is one of the experimental devices for nuclear physics at RAON. It focuses on the nuclear symmetry energy at supra-saturation densities. The LAMPS Collaboration has developed and constructed various detector elements, including a time projection chamber (TPC) and a forward neutron detector array. From the positron beam test, the drift velocity of the secondary electrons in the TPC is 5.3 ± 0.2 cm/μ s with P10 gas mixture, and the position resolution for pads with dimensions of 4 × 15 mm² is in the range of ∼ 0.6–0.8 mm, depending on the beam position. From the neutron beam test, the energy resolution of the prototype neutron detector module is determined to be 3.4%, and the position resolution is estimated to be better than 5.28 cm. At present, the construction of the LAMPS neutron detector system is in progress.