[en] The TRIUMF Centre for Molecular and Materials Sciences (MMS) supports a MuSR user facility and a βNMR research program. An overview of this infrastructure, and its future prospects, are presented. (author)

[en] We developed a beam scraper that can handle up to 2 MW proton beams and replaced the conventional scraper with the new one. For the replacement work, Monte Carlo calculation code was carried out to evaluate the protection of induced radiation by 3-GeV proton beam irradiation. New scraper is running smoothly at 0.5 MW operation and can withstand the upgrading of the beam power that is planned in the future. (author)

[en] We have developed a general purpose μSR spectrometer ARTEMIS and installed at S1 experimental area of MLF, J-PARC. The new spectrometer has the identical design with the D1-spectrometer developed in 2013; the common design of the two general purposes spectrometers helps sharing the sample environment apparatus and direct comparison of the beam characteristics between the two experimental areas. We have upgraded the front-end circuit of positron/electron detectors, and achieved high enough hit rate tolerance for muon beam available in the future 1 MW operation of MLF. Other revisions and modifications, which became necessary after the commissioning and the actual usage of the S1/D1 spectrometers have been applied to both of the twin spectrometers. (author)

[en] For the last 30 years, muon experiments at ISIS have been making a significant contribution to a number of scientific fields. However, as a community of researchers, we are always aiming to improve and extend the instruments' capabilities. In this paper, we will review key developments at the ISIS muon facility, the primary beamline upgrade and recent technique developments, before taking a forward look to new projects, such as: the upgrade for MuSR, e-learning, detector development and sample environment. (author)

[en] The 14th International Conference on Muon Spin Rotation, Relaxation, and Resonance (μSR2017) was held in Sapporo, Japan from 25th to 30th June 2017 at Hokkaido University. The conference provided the opportunity for researchers from around the world with interests in the application of μSR, β-NMR, and muonic x-rays to a wide range of topics in condensed matter physics, inorganic and organic chemistry, electrochemistry, biology, materials science, fundamental physics, and facility developments to know the recent situation and progress in each topic. The conference was attended by 181 researchers (with a further 12 accompanying persons) from 16 countries; 45 of whom registered as students. During the conference, a total of 181 talks and posters were presented, which is accidentally the same number to the attended researchers. More correctly, the talks consisted of a Yamazaki-prize lecture, 7 invited talks, 36 oral presentations, 136 poster presentations, and a summary talk by Elvezio Morenzoni. These conference proceedings contain 66 refereed publications from presentations covering magnetism, superconductivity, chemistry, electrochemistry, semiconductors, biophysics, muonic x-ray elemental analysis, and techniques. The presented papers are indexed individually. (J.P.N.)

[en] A pulsed muon beam with unprecedented intensity will be generated by a 3-GeV 333-microA proton beam on a muon target made of 20-mm thick isotropic graphite at J-PARC MLF MUSE (Muon Science Establishment). The first muon beam was successfully generated on September 26th, 2008. Gradually upgrading the beam intensity, continuous 300-kW proton beam has been operated by a fixed target method without replacements till June of 2014. However, the lifetime of the fixed target was anticipated to be less than 1 year by the proton-irradiation damage of the graphite through 1-MW beam operation. To extend the lifetime, a muon rotating target, in which the radiation damage is distributed to a wider area, was installed in September of 2014, and continuous and stable operation has been successfully performed. Because the muon target becomes highly radioactive by the proton irradiation, the maintenance is conducted by remote handling in the Hot cell. In September of 2015, a scraper No. 1 to collimate the proton beam scattered by the target was replaced for further high-power beam operation. Recently, new developments on monitoring and maintenance of the muon target for higher power operation are in progress. In this article, perspective of muon production target at J-PARC MLF MUSE will be described. (author)

[en] At the new DC muon beamline MuSIC at Research Center for Nuclear Physics (RCNP), Osaka University, the beamline construction from the solenoid system of the muon production to the experimental port was completed. A beamline commissioning and a feasibility study for μSR are now in progress. With newly refurbished spectrometer installed at the experimental port, we succeeded in observing μSR spectra and μ-e decay asymmetry in a simple setup down to 4 K. We are still under development of other μSR apparatuses. (author)

[en] At J-PARC MUSE (Muon Science Establishment), one graphite target was installed in the proton beam line on the way to the neutron source, from which four sets of the secondary lines were designed to be extracted and extended into two experimental halls (toward the west wing, one decay-surface muon channel (D-Line) and the axial focusing muon channel (U-Line), and towards the east wing one surface muon channel (S-Line) and one fundamental muon channel (H-Line). MUSE has been suffering from many troubles such as the giant earthquake, fire, twice water leakage from the neutron target. Although the proton beam intensity was restricted lower than 200 kW, we have been having a rather stable operation at the MUSE since February, 2016. In this paper, the latest situation on the MUSE is reported. (author)

[en] We propose the next generation of precision microwave spectroscopy measurements of the ground state hyperfine structure (HFS) of the muonic helium atom. The HFS interval is a sensitive tool to test three-body atomic system and bound-state QED theory as well as precise direct determination of the negative muon magnetic moment and hence its mass. Previous measurements performed in 1980s at PSI and LAMPF had uncertainties dominated by statistical errors. The new high-intensity pulsed negative muon beam at J-PARC MUSE give an opportunity to improve these measurements by nearly two orders of magnitude for the HFS interval, and almost tenfold for the negative muon mass, thus providing a more precise test of CPT invariance and determination of the negative counterpart of the anomalous g-factor for the existing BNL muon g-2 experiment. Both measurements at zero field and at high magnetic field are considered. An overview of the different aspects of these new muonic helium HFS measurements is presented. (author)

[en] Zero-field muon spin relaxation measurements were carried out on an Al-3.4%Zn-1.9%Mg alloy in the temperature range from 10 to 300 K. A sample heat treatment clearly made an effect on the relaxation rates of Al-3.4%Zn-1.9%Mg alloys; the dipole width and trapping rate of the heat-treated sample were smaller than those of the non-treated sample below 140 K. The temperature dependence of the trapping and detrapping rates was used to estimate activation energies of muons in Al-3.4%Zn-1.9%Mg. (author)