Current status of RAON muon irradiation system (RAMIS) for μSR spectrometer at RAON

Abstract

A muon beam line, called as RAMIS (RAON Muon Irradiation System), was constructed as a part of the Rare isotope Accelerator complex for ON-line experiment (RAON) facility at the Institute for Rare Isotope Science (IRIS) in Korea. The muon beam line will be utilized to provide an almost 100% spin-polarized surface muon beam as a magnetic probe for various experimental studies for structure and dynamics of matter. The integration test was performed for the purpose of evaluation of the muon beam transport system and the nominal performance of the spin rotator. β-particle transport test was performed using 106Ru/Rh radioactive source, and its transport to the sample irradiation position of F2 was verified by beam profile measurement. The conditioning test of the spin rotator suggested its nominal performance, particularly operation voltages of ± 120 kV to two electrodes. We report on the current status of the muon beam line, including muon production system, proton beam dump, muon beam transport line, and spin rotator. The test result of the β-particle transport and the spin rotator conditioning are also presented.