“Three-dimensional spiral beam injection scheme” [1] is a key to realize J-PARC muon g-2/EDM experiment exploring the beyond standard model of elementary physics. Muon is stored in a compact orbit of 0.33 m radius in the super conducting solenoid storage magnet. Appropriate X-Y coupled beam phase space, which strongly coupled radial and solenoid axes, is crucial to inject the beam passing through the static solenoid fringe field. Vertical kicker [2] is also crucial to stabilize beam motion in the storage ring. In this report, results from the validation experiment [3] which utilize 80 keV electron beam and super compact storage ring with 0.12 m radius orbit are discussed: how well we do with (1) extended Twiss parameters for X-Y coupled beam in accordance with parameter weighting priority, (2) evaluate four-dimensional sigma-matrix of such strongly X-Y coupled beam phase space, (3) control the beam size during the injection, especially along the solenoid-axis. Utilizing several beam diagnostic methods in the storage volume (beam visualization monitor, wire-scan system), we discuss comparison between design and real data, and judge strategic robustness.

To realize very precise measurement of the muon spin precession frequency in the level of sub-ppm, a muon beam is injected into a precisely adjusted storage magnet of sub-ppm uniformity via “Three-dimensional spiral beam injection scheme [1]” at J-PARC muon g-2/EDM experiment. This injection scheme requires a strongly X-Y coupled beam which is applied by eight rotating quadrupoles on the 10m of beam transport line [2]. Currently we have two scenarios of set of rotation angles (1) 45 or 60 degrees fixed, (2) any angles. In this presentation, strategy to precise control of the X-Y coupling at the beam transport line is discussed: how to control/monitor X-Y coupled phase space with eight rotatable quadrupole magnets including its alignment requirements for the case of (1) and (2). Results of alignment of the newly developed mount system for the rotating quad is also introduced. A pair of dedicated magnets called active shield multipole magnet (ASXM) will be set at the entrance and the exit of the beam channel of the storage magnet yoke. These devices will guarantee how well the beam phase space is matched with requirements at the reference point inside the storage magnet [3].

Anomalous magnetic moment (g-2) of a muon has been precisely measured by the BNL and FNAL experiments, and there is a discrepancy from the Standard Model prediction. A new measurement of muon g-2 is planned at J-PARC based on a different strategy. In the J-PARC experiment, a low emittance 300 MeV muon beam is injected into a compact storage orbit by newly developed 3-D spiral injection scheme*. Injected muons follow a vertical betatron oscillation around the storage orbit. A reduction of betatron oscillation amplitude is a key to achieve the physics goal of this experiment. This paper presents a new beam profile monitor which measures vertical distribution of stored muons to realize the 3-D spiral injection and to minimize vertical oscillation amplitude. There is a stringent requirement on the effective material budget in order to suppress multiple scattering of muon beam which passes through this monitor for hundred times on every cyclotron period. To achieve this, the monitor utilizes thin scintillating fibers of 0.2 mm diameter are placed with an interval of 10 mm. Reconstruction procedure of vertical beam motion from measured hit distribution will also be discussed.