Development of the CsI(Tl) Muon Beam Profile Monitor for the Muon g − 2/EDM Experiment at J-PARC

In this work a muon beam profile monitor based on a thin CsI(Tl) screen with optical readout is suggested. This monitor is intended to measure an upcoming surface muon beam to the silica aerogel target of the muon g−2/EDM experiment at J-PARC. The measurements of luminophore foil parameters with a camera were done as well as the test of the monitor prototype with a surface muon beam at D2 beamline in J-PARC MLF

Development of the CsI(Tl) Muon Beam Profile Monitor for the Muon

In this work a muon beam profile monitor based on a thin CsI(Tl) screen with optical readout is suggested. This monitor is intended to measure an upcoming surface muon beam to the silica aerogel target of the muon g−2/EDM experiment at J-PARC. The measurements of luminophore foil parameters with a camera were done as well as the test of the monitor prototype with a surface muon beam at D2 beamline in J-PARC MLF

Design and Beam Dynamics Study of Disk-Loaded Structure for Muon Linac

The disk-loaded structures (DLS) in the muon LINAC are under development for the J-PARC muon g-2/EDM experiment. Four DLSs with an accelerating gradient of 20 MV/m take charge of muon acceleration from 40 MeV to 212 MeV, which corresponds to 70% to 94% of the speed of light. The quasi-constant gradient type TM01-2pi/3 mode DLSs with gradually varying disk spacing was designed and confirmed that the cumulative phase slip due to the mismatch between muon and phase velocity can be suppressed to less than 2 degrees at the frequency of 2592 MHz. In addition, the optimum synchronous phase and the lattice were investigated to satisfy the requirements of the total emittance less than 1.5 pi mm mrad and the momentum spread less than 0.1% in RMS

Fabrication and Low-Power Test of Disk-and-Washer Cavity for Muon Acceleration

The muon g-2/EDM experiment is under preparation at Japan Proton Accelerator Research Complex (J-PARC), and the muon linear accelerator for the experiment is being developed. A Disk-and-Washer (DAW) cavity will be used for the medium-velocity part of the accelerator, and muons will be accelerated from v/c=ß=0.3 to 0.7 with the operating frequency of 1.296 GHz. Machining, brazing, and low-power measurements of a prototype cell reflecting the design of the first tank of DAW were performed to identify fabrication problems. Several problems were identified, such as displacement of washers during brazing, and some measures will be taken in the actual tank fabrication. In this paper, the results of the prototype cell fabrication will be reported

New beamlines and future prospects of the J-PARC muon facility

At the J-PARC muon facility (MUSE), new beamlines started operation recently. H-line is a high-intensity pulsed muon beamline for fundamental physics experiments. The first beam of the H-line was delivered to its first branch (H1 area) in January 2022, where a precise measurement of the muonium hyperfine structure and a search for μ-e conversion will be conducted. Further extension of the second branch of the H-line for a muon g-2/EDM experiment and a transmission muon microscope project is also ongoing. In addition, the second branch of the surface muon beamline (S2 area of the S-line) was opened for a muonium 1S-2S spectroscopy experiment in FY2021. In this paper, the recent upgrade and present status of the J-PARC muon facility and its prospects are presented