Intense beam of metastable Muonium

Precision spectroscopy of the Muonium Lamb shift and fine structure requires a robust source of 2S Muonium. To date, the beam-foil technique is the only demonstrated method for creating such a beam in vacuum. Previous experiments using this technique were statistics limited, and new measurements would benefit tremendously from the efficient 2S production at a low energy muon ($$<20$$ < 20 keV) facility. Such a source of abundant low energy $${\mu }^{+}$$ μ + has only become available in recent years, e.g. at the Low-Energy Muon beamline at the Paul Scherrer Institute. Using this source, we report on the successful creation of an intense, directed beam of metastable Muonium. We find that even though the theoretical Muonium fraction is maximal in the low energy range of 2–5 keV, scattering by the foil and transport characteristics of the beamline favor slightly higher $${\mu }^{+}$$ μ + energies of 7–10 keV. We estimate that an event detection rate of a few events per second for a future Lamb shift measurement is feasible, enabling an increase in precision by two orders of magnitude over previous determinations.

ID30A-3 (MASSIF-3) – a beamline for macromolecular crystallography at the ESRF with a small intense beam

ID30A-3 (or MASSIF-3) is a mini-focus (beam size 18 µm × 14 µm) highly intense (2.0 × 1013 photons s−1), fixed-energy (12.81 keV) beamline for macromolecular crystallography (MX) experiments at the European Synchrotron Radiation Facility (ESRF). MASSIF-3 is one of two fixed-energy beamlines sited on the first branch of the canted undulator setup on the ESRF ID30 port and is equipped with a MD2 micro-diffractometer, a Flex HCD sample changer, and an Eiger X 4M fast hybrid photon-counting detector. MASSIF-3 is recommended for collecting diffraction data from single small crystals (≤15 µm in one dimension) or for experiments using serial methods. The end-station has been in full user operation since December 2014, and here its current characteristics and capabilities are described.

Measurement of radioactivity and evaluation of activated nuclides due to secondary particles produced in stripper foil in J-PARC RCS

Multi-turn charge-exchange beam injection is the key technique to achieve high-intensity proton beam accelerators. In J-PARC RCS, 400-MeV H- beams from LINAC are injected into stripper foils such that most of the beams are converted into protons. The stripper foils are irradiated not only with the injected H- beams but also with the protons circulating during the beam injection period. The high energy and intense beam irradiation into the foil generates secondary neutrons and protons via nuclear reactions. These secondary particles cause high residual activation around the stripper foils. Therefore, an activation analysis method that uses sample pieces is required to investigate the secondary particle. Furthermore, a new experimental system to measure secondary particles from the foil was installed at the L3BT 100BD line. Initial testing of the system has been completed, and beam testing will commence in October 2018.