Progress of beam-transport simulations of S-line at J-PARC

by Ms Phanthip Jaikaew (RIKEN/Chaing Mai University)

Thursday 23 May 2024, 14:00 → 15:00 Europe/Zurich

SZ-WBGB/019

The Materials and Life Science Facility (MLF) at J-PARC can provide both neutrons and muons. The surface-muon beamline (S-line) is designed to accommodate four experimental areas (S1-S4). In 2017, the surface-muon flux reached 8.5 × 10⁴ per second during 150 kW operation at the end of S1, with a tailored beam spot size of ø20 mm. Currently, two beamlines, S1 and S2, are operational. Our group intends to introduce a new muon beamline, S3, in the space between S1 and S2, in collaboration with the KEK muon group. To maximize muon-transport efficiency to the new beamline, we are now re-simulating the beam transport from the muon-production target using Monte Carlo simulation programs, specifically G4beamline. The results showed a ~95% proton transmission through the muon target. At the S-line entrance, the surface muon yield is 1.43 × 10⁻⁷. The transverse positional distribution and phase space of the surface muon beam were used for beam dynamic calculations and will be provided in this presentation.